Journal articles on the topic 'Scaffold-host integration'
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Cui, Lei, Jing Li, Yunze Long, Min Hu, Jinqing Li, Zhanjun Lei, Hongjun Wang, Rong Huang, and Xueyong Li. "Vascularization of LBL structured nanofibrous matrices with endothelial cells for tissue regeneration." RSC Advances 7, no. 19 (2017): 11462–77. http://dx.doi.org/10.1039/c6ra26931a.
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Smith, S. E., R. A. White, D. A. Grant, and S. A. Grant. "The Use of a Green Fluorescent Protein Porcine Model to Evaluate Host Tissue Integration into Extracellular Matrix Derived Bionanocomposite Scaffolds." International Journal of Tissue Engineering 2015 (January 8, 2015): 1–10. http://dx.doi.org/10.1155/2015/586493.
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When using heterogeneous extracellular matrix (ECM) derived scaffolds for soft tissue repair, current methods of in vivo evaluation can fail to provide a clear distinction between host collagen and implanted scaffolds making it difficult to assess host tissue integration and remodeling. The purpose of this study is both to evaluate novel scaffolds conjugated with nanoparticles for host tissue integration and biocompatibility and to assess green fluorescent protein (GFP) expressing swine as a new animal model to evaluate soft tissue repair materials. Human-derived graft materials conjugated with nanoparticles were subcutaneously implanted into GFP expressing swine to be evaluated for biocompatibility and tissue integration through histological scoring and confocal imaging. Histological scoring indicates biocompatibility and remodeling of the scaffolds with and without nanoparticles at 1, 3, and 6 months. Confocal microscope images display host tissue integration into scaffolds although nonspecificity of GFP does not allow for quantification of integration. However, the confocal images do allow for spatial observation of host tissue migration into the scaffolds at different depths of penetration. The study concludes that the nanoparticle scaffolds are biocompatible and promote integration and that the use of GFP expressing swine can aid in visualizing the scaffold/host interface and host cell/tissue migration.
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Miceli, Giovanni Carlo, Fabio Salvatore Palumbo, Francesco Paolo Bonomo, Massimiliano Zingales, and Mariano Licciardi. "Polybutylene Succinate Processing and Evaluation as a Micro Fibrous Graft for Tissue Engineering Applications." Polymers 14, no. 21 (October 23, 2022): 4486. http://dx.doi.org/10.3390/polym14214486.
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A microfibrous tubular scaffold has been designed and fabricated by electrospinning using poly (1,4-butylene succinate) as biocompatible and biodegradable material. The scaffold morphology was optimized as a small diameter and micro-porous conduit, able to foster cell integration, adhesion, and growth while avoiding cell infiltration through the graft’s wall. Scaffold morphology and mechanical properties were explored and compared to those of native conduits. Scaffolds were then seeded with adult normal human dermal fibroblasts to evaluate cytocompatibility in vitro. Haemolytic effect was evaluated upon incubation with diluted whole blood. The scaffold showed no delamination, and mechanical properties were in the physiological range for tubular conduits: elastic modulus (17.5 ± 1.6 MPa), ultimate tensile stress (3.95 ± 0.17 MPa), strain to failure (57 ± 4.5%) and suture retention force (2.65 ± 0.32 N). The shown degradation profile allows the graft to provide initial mechanical support and functionality while being colonized and then replaced by the host cells. This combination of features might represent a step toward future research on PBS as a biomaterial to produce scaffolds that provide structure and function over time and support host cell remodelling.
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Alnojeidi, Hatem, Ruhangiz Taghi Kilani, and Aziz Ghahary. "Evaluating the Biocompatibility of an Injectable Wound Matrix in a Murine Model." Gels 8, no. 1 (January 9, 2022): 49. http://dx.doi.org/10.3390/gels8010049.
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(1) Background: Developing a high-quality, injectable biomaterial that is labor-saving, cost-efficient, and patient-ready is highly desirable. Our research group has previously developed a collagen-based injectable scaffold for the treatment of a variety of wounds including wounds with deep and irregular beds. Here, we investigated the biocompatibility of our liquid scaffold in mice and compared the results to a commercially available injectable granular collagen-based product. (2) Methods: Scaffolds were applied in sub-dermal pockets on the dorsum of mice. To examine the interaction between the scaffolds and the host tissue, samples were harvested after 1 and 2 weeks and stained for collagen content using Masson’s Trichrome staining. Immunofluorescence staining and quantification were performed to assess the type and number of cells infiltrating each scaffold. (3) Results: Histological evaluation after 1 and 2 weeks demonstrated early and efficient integration of our liquid scaffold with no evident adverse foreign body reaction. This rapid incorporation was accompanied by significant cellular infiltration of stromal and immune cells into the scaffold when compared to the commercial product (p < 0.01) and the control group (p < 0.05). Contrarily, the commercial scaffold induced a foreign body reaction as it was surrounded by a capsule-like, dense cellular layer during the 2-week period, resulting in delayed integration and hampered cellular infiltration. (4) Conclusion: Results obtained from this study demonstrate the potential use of our liquid scaffold as an advanced injectable wound matrix for the management of skin wounds with complex geometries.
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Luo, Ziming, Kang Li, Kaijing Li, Bikun Xian, Ying Liu, Sijing Yang, Chaochao Xu, et al. "Establishing a Surgical Procedure for Rhesus Epiretinal Scaffold Implantation with HiPSC-Derived Retinal Progenitors." Stem Cells International 2018 (2018): 1–10. http://dx.doi.org/10.1155/2018/9437041.
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Background. To develop an effective surgical procedure for cellular scaffold epiretinal implantation in rhesus, facilitating subsequent epiretinal stem cell transplantation. Methods. Retinal progenitors were seeded onto a poly(lactic-co-glycolic) acid (PLGA) scaffold. First, the cellular scaffolds were delivered by 18G catheter or retinal forceps into rabbit epiretinal space (n=50). Then, the cell survival rate was evaluated by Cell Counting Kit-8 (CCK-8). Second, three methods of scaffold fixation, including adhesion after gas-liquid exchange (n=1), tamponade by hydrogel (n=1), and fixation by retinal tacks (n=4), were performed in rhesus monkeys. After one month, fundus photography and SD-OCT were performed to assess the outcomes, and histological examination was performed to evaluate proliferation. Results. The cell survival rate was significantly higher in the catheter group. Follow-up examination showed that retinal tack fixation was the only method to maintain the scaffolds attached to host retina for at least 3 weeks, which is the minimal time required for cell integration. Histological staining demonstrated slight glial fibrillary acidic protein (GFAP) accumulation in the retinal tack insertion area. Conclusions. The established surgical procedure offers a new insight into research of epiretinal cell replacement therapy in rhesus eyes. The successful delivery and long-term fixation provide a prerequisite for cell migration and integration.
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Lu, H. H., J. Jiang, Ai Tao Tang, C. T. Hung, and X. E. Guo. "Development of Controlled Heterogeneity on a Polymer-Ceramic Hydrogel Scaffold for Osteochondral Repair." Key Engineering Materials 284-286 (April 2005): 607–10. http://dx.doi.org/10.4028/www.scientific.net/kem.284-286.607.
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Due to its intrinsically poor repair potential, injuries to articular cartilage do not heal and clinical intervention is required. Osteochondral grafts may improve healing while promoting integration with host tissue. We report here the development of an osteochondral graft based on a hybrid of a hyrogel and a polymer-bioactive glass composite (PLAGA-BG) microsphere scaffold. This novel osteochondral construct consists of three regions: gel-only, gel/composite interface, and a composite-only-region. The three phases differ in calcium phospate (Ca-P) or BG content. The objective of the current study is to investigate the effects of scaffold composition on chondrocyte response, and to evaluate the effects of co-culture on osteoblasts and chondrocyte growh and differentiation on the hybrid scaffold. The PLAGA-BG microsphere scaffold supported the growth of chondrocytes and initial results indicate that in the presence of BG, chondrocyte-mediated mineralization may be stimulated. Co-culture of osteoblasts and chondrocytes on the multi-phased scaffold with varied Ca-P content facilitated the formation of multiple matrix zones: a GAGrich chondrocyte region, an interfacial matrix rich in GAG+collagen, and a mineralized collagen matrix with osteoblasts. In summary, chondrocyte response has been optimized as a function of scaffold composition and the novel osteochondral graft has the potential to support the simultaneous formation of multiple types of tissue in vitro.
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Kitajima, Hiroaki, Makoto Hirota, Keiji Komatsu, Hitoshi Isono, Takanori Matsuura, Kenji Mitsudo, and Takahiro Ogawa. "Ultraviolet Light Treatment of Titanium Microfiber Scaffolds Enhances Osteoblast Recruitment and Osteoconductivity in a Vertical Bone Augmentation Model: 3D UV Photofunctionalization." Cells 12, no. 1 (December 21, 2022): 19. http://dx.doi.org/10.3390/cells12010019.
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Vertical bone augmentation to create host bone prior to implant placement is one of the most challenging regenerative procedures. The objective of this study is to evaluate the capacity of a UV-photofunctionalized titanium microfiber scaffold to recruit osteoblasts, generate intra-scaffold bone, and integrate with host bone in a vertical augmentation model with unidirectional, limited blood supply. Scaffolds were fabricated by molding and sintering grade 1 commercially pure titanium microfibers (20 μm diameter) and treated with UVC light (200–280 nm wavelength) emitted from a low-pressure mercury lamp for 20 min immediately before experiments. The scaffolds had an even and dense fiber network with 87% porosity and 20–50 mm inter-fiber distance. Surface carbon reduced from 30% on untreated scaffold to 10% after UV treatment, which corresponded to hydro-repellent to superhydrophilic conversion. Vertical infiltration testing revealed that UV-treated scaffolds absorbed 4-, 14-, and 15-times more blood, water, and glycerol than untreated scaffolds, respectively. In vitro, four-times more osteoblasts attached to UV-treated scaffolds than untreated scaffolds three hours after seeding. On day 2, there were 70% more osteoblasts on UV-treated scaffolds. Fluorescent microscopy visualized confluent osteoblasts on UV-treated microfibers two days after seeding but sparse and separated cells on untreated microfibers. Alkaline phosphatase activity and osteocalcin gene expression were significantly greater in osteoblasts grown on UV-treated microfiber scaffolds. In an in vivo model of vertical augmentation on rat femoral cortical bone, the interfacial strength between innate cortical bone and UV-treated microfiber scaffold after two weeks of healing was double that observed between bone and untreated scaffold. Morphological and chemical analysis confirmed seamless integration of the innate cortical and regenerated bone within microfiber networks for UV-treated scaffolds. These results indicate synergy between titanium microfiber scaffolds and UV photofunctionalization to provide a novel and effective strategy for vertical bone augmentation.
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Altinova, Haktan, Pascal Achenbach, Moniek Palm, Istvan Katona, Emmanuel Hermans, Hans Clusmann, Joachim Weis, and Gary Anthony Brook. "Characterization of a Novel Aspect of Tissue Scarring Following Experimental Spinal Cord Injury and the Implantation of Bioengineered Type-I Collagen Scaffolds in the Adult Rat: Involvement of Perineurial-like Cells?" International Journal of Molecular Sciences 23, no. 6 (March 16, 2022): 3221. http://dx.doi.org/10.3390/ijms23063221.
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Numerous intervention strategies have been developed to promote functional tissue repair following experimental spinal cord injury (SCI), including the bridging of lesion-induced cystic cavities with bioengineered scaffolds. Integration between such implanted scaffolds and the lesioned host spinal cord is critical for supporting regenerative growth, but only moderate-to-low degrees of success have been reported. Light and electron microscopy were employed to better characterise the fibroadhesive scarring process taking place after implantation of a longitudinally microstructured type-I collagen scaffold into unilateral mid-cervical resection injuries of the adult rat spinal cord. At long survival times (10 weeks post-surgery), sheets of tightly packed cells (of uniform morphology) could be seen lining the inner surface of the repaired dura mater of lesion-only control animals, as well as forming a barrier along the implant–host interface of the scaffold-implanted animals. The highly uniform ultrastructural features of these scarring cells and their anatomical continuity with the local, reactive spinal nerve roots strongly suggest their identity to be perineurial-like cells. This novel aspect of the cellular composition of reactive spinal cord tissue highlights the increasingly complex nature of fibroadhesive scarring involved in traumatic injury, and particularly in response to the implantation of bioengineered collagen scaffolds.
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Koch, Holger, Cora Graneist, Frank Emmrich, Holger Till, Roman Metzger, Heike Aupperle, Katrin Schierle, Ulrich Sack, and Andreas Boldt. "Xenogenic Esophagus Scaffolds Fixed with Several Agents: ComparativeIn VivoStudy of Rejection and Inflammation." Journal of Biomedicine and Biotechnology 2012 (2012): 1–11. http://dx.doi.org/10.1155/2012/948320.
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Most infants with long-gap esophageal atresia receive an esophageal replacement with tissue from stomach or colon, because the native esophagus is too short for true primary repair. Tissue-engineered esophageal conducts could present an attractive alternative. In this paper, circular decellularized porcine esophageal scaffold tissues were implanted subcutaneously into Sprague-Dawley rats. Depending on scaffold cross-linking with genipin, glutaraldehyde, and carbodiimide (untreated scaffolds : positive control; bovine pericardium : gold standard), the number of infiltrating fibroblasts, lymphocytes, macrophages, giant cells, and capillaries was determined to quantify the host response after 1, 9, and 30 days. Decellularized esophagus scaffolds were shown to maintain native matrix morphology and extracellular matrix composition. Typical inflammatory reactions were observed in all implants; however, the cellular infiltration was reduced in the genipin group. We conclude that genipin is the most efficient and best tolerated cross-linking agent to attenuate inflammation and to improve the integration of esophageal scaffolds into its surrounding tissue after implantation.
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Baino, Francesco, Francesca Tallia, Giorgia Novajra, Joaquim Minguella, Maria Angeles Montealegre, Feza Korkusuz, and Chiara Vitale-Brovarone. "Novel Bone-Like Porous Glass Coatings on Al2O3 Prosthetic Substrates." Key Engineering Materials 631 (November 2014): 236–40. http://dx.doi.org/10.4028/www.scientific.net/kem.631.236.
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Over the last two decades, the philosophy behind an optimal fixation of orthopaedic implants progressively evolved towards “bone-conservative” solutions and, accordingly, the researchers’ attention moved from simple mechanical fixation of the prosthesis to host bone by using screws or acrylic cement to new strategies based on a physico-chemical bond (surface modification) in order to minimize bone resection/loss and maximize tissue-implant integration. This research work explores the feasibility of a novel bioceramic single-piece acetabular cup for hip joint prosthesis that can be anchored to the patient’s pelvic bone by means of a bone-like trabecular coating (scaffold) able to promote implant osteointegration.
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Hacker, D., and M. M. Fluck. "High-level recombination specific to polyomavirus genomes targeted to the integration-transformation pathway." Molecular and Cellular Biology 9, no. 3 (March 1989): 995–1004. http://dx.doi.org/10.1128/mcb.9.3.995-1004.1989.
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An unusually high incidence of interviral recombination was found in the process of integration of the polyomavirus genome concomitant with neoplastic transformation of nonpermissive cells. Transformants were isolated after mixed infections of Fischer rat cells with two mutants lacking restriction endonuclease sites and were analyzed for the presence of unselected integrated recombinant restriction fragments. A large fraction of the transformants isolated (38% of the 64 transformed cell lines studied) contained recombinant viral genomes that had undergone recombination in a 1.3-, 1.7-, or 3.6-kilobase-pair interval. More than 90% of these recombinant transformants showed evidence of crossovers in multiple intervals. To our knowledge, the recombination frequencies observed in these experiments represent the highest frequencies of homologous recombination reported for a mitotic mammalian system that does not involve transfection. In contrast to the elevated level of recombination in the integrated viral genomes, no evidence of recombination was obtained among the replicated unintegrated pool of viral genomes isolated from the same population of infected cells from which the recombinant transformants were derived. Either of two hypotheses can provide an explanation for the segregated recombination: either recombination occurs at elevated levels in a small, recombination-prone fraction of the population destined to become transformed, or recombination occurs only among those viral genomes which are engaged in the process of integration and thus interact with a recombinogenic host machinery (for example, the host scaffold). We favor the latter hypothesis.
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Hacker, D., and M. M. Fluck. "High-level recombination specific to polyomavirus genomes targeted to the integration-transformation pathway." Molecular and Cellular Biology 9, no. 3 (March 1989): 995–1004. http://dx.doi.org/10.1128/mcb.9.3.995.
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An unusually high incidence of interviral recombination was found in the process of integration of the polyomavirus genome concomitant with neoplastic transformation of nonpermissive cells. Transformants were isolated after mixed infections of Fischer rat cells with two mutants lacking restriction endonuclease sites and were analyzed for the presence of unselected integrated recombinant restriction fragments. A large fraction of the transformants isolated (38% of the 64 transformed cell lines studied) contained recombinant viral genomes that had undergone recombination in a 1.3-, 1.7-, or 3.6-kilobase-pair interval. More than 90% of these recombinant transformants showed evidence of crossovers in multiple intervals. To our knowledge, the recombination frequencies observed in these experiments represent the highest frequencies of homologous recombination reported for a mitotic mammalian system that does not involve transfection. In contrast to the elevated level of recombination in the integrated viral genomes, no evidence of recombination was obtained among the replicated unintegrated pool of viral genomes isolated from the same population of infected cells from which the recombinant transformants were derived. Either of two hypotheses can provide an explanation for the segregated recombination: either recombination occurs at elevated levels in a small, recombination-prone fraction of the population destined to become transformed, or recombination occurs only among those viral genomes which are engaged in the process of integration and thus interact with a recombinogenic host machinery (for example, the host scaffold). We favor the latter hypothesis.
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Villet, Outi M., Antti Siltanen, Tommi Pätilä, M. Ali A. Mahar, Antti Vento, Esko Kankuri, and Ari Harjula. "Advances in Cell Transplantation Therapy for Diseased Myocardium." Stem Cells International 2011 (2011): 1–8. http://dx.doi.org/10.4061/2011/679171.
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The overall objective of cell transplantation is to repopulate postinfarction scar with contractile cells, thus improving systolic function, and to prevent or to regress the remodeling process. Direct implantation of isolated myoblasts, cardiomyocytes, and bone-marrow-derived cells has shown prospect for improved cardiac performance in several animal models and patients suffering from heart failure. However, direct implantation of cultured cells can lead to major cell loss by leakage and cell death, inappropriate integration and proliferation, and cardiac arrhythmia. To resolve these problems an approach using 3-dimensional tissue-engineered cell constructs has been investigated. Cell engineering technology has enabled scaffold-free sheet development including generation of communication between cell graft and host tissue, creation of organized microvascular network, and relatively long-term survival afterin vivotransplantation.
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Chen, Jishizhan. "Recent Development of Biomaterials Combined with Mesenchymal Stem Cells as a Strategy in Cartilage Regeneration." International Journal of Translational Medicine 2, no. 3 (August 29, 2022): 456–81. http://dx.doi.org/10.3390/ijtm2030035.
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Osteoarthritis leads to the progressive decay of articular cartilage. Due to its intrinsic avascular character, cartilage shows an inadequate capacity for regeneration. Cartilage loss may result in chronic pain, movement disorder and morbidity, which lack effective treatments except for joint replacement for late-stage osteoarthritis. To overcome this challenge, tissue engineering has emerged as a promising method. Scaffolds provide mechanical and biochemical support to stem cells that undergo differentiation and secrete a cartilage-specific matrix, and this strategy has been proven to have positive results. However, there is still a gap between the current strategy and perfection. Researchers are confronted with difficulties such as poor cell survival, insufficient differentiation, hypertrophy and endochondral calcification of neocartilage, and inadequate integration into the host tissue. The current research focuses on modifying scaffold parameters, including composition, stiffness, pore size, surface morphology, hydrophilicity and electric charge. On the other hand, cell regulation is another focus, including predifferentiation, gene editing, dynamic mechanical stimulus, and hypoxia. This review aims to provide a comprehensive discussion of existing challenges, scaffold types and properties, practical methods to improve chondrogenic potential and an outlook on future trends in cartilage bioengineering.
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Wang, Hsueh-Chun, Tzu-Hsiang Lin, Che-Chia Hsu, and Ming-Long Yeh. "Restoring Osteochondral Defects through the Differentiation Potential of Cartilage Stem/Progenitor Cells Cultivated on Porous Scaffolds." Cells 10, no. 12 (December 14, 2021): 3536. http://dx.doi.org/10.3390/cells10123536.
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Cartilage stem/progenitor cells (CSPCs) are cartilage-specific, multipotent progenitor cells residing in articular cartilage. In this study, we investigated the characteristics and potential of human CSPCs combined with poly(lactic-co-glycolic acid) (PLGA) scaffolds to induce osteochondral regeneration in rabbit knees. We isolated CSPCs from human adult articular cartilage undergoing total knee replacement (TKR) surgery. We characterized CSPCs and compared them with infrapatellar fat pad-derived stem cells (IFPs) in a colony formation assay and by multilineage differentiation analysis in vitro. We further evaluated the osteochondral regeneration of the CSPC-loaded PLGA scaffold during osteochondral defect repair in rabbits. The characteristics of CSPCs were similar to those of mesenchymal stem cells (MSCs) and exhibited chondrogenic and osteogenic phenotypes without chemical induction. For in vivo analysis, CSPC-loaded PLGA scaffolds produced a hyaline-like cartilaginous tissue, which showed good integration with the host tissue and subchondral bone. Furthermore, CSPCs migrated in response to injury to promote subchondral bone regeneration. Overall, we demonstrated that CSPCs can promote osteochondral regeneration. A monophasic approach of using diseased CSPCs combined with a PLGA scaffold may be beneficial for repairing complex tissues, such as osteochondral tissue.
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Beisbayeva, Zhuldyz, Ainur Zhanbassynova, Gulzada Kulzhanova, Fariza Mukasheva, and Cevat Erisken. "Change in Collagen Fibril Diameter Distribution of Bovine Anterior Cruciate Ligament upon Injury Can Be Mimicked in a Nanostructured Scaffold." Molecules 26, no. 5 (February 24, 2021): 1204. http://dx.doi.org/10.3390/molecules26051204.
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More than 200,000 people are suffering from Anterior Cruciate Ligament (ACL) related injuries each year in the US. There is an unmet clinical demand for improving biological attachment between grafts and the host tissue in addition to providing mechanical support. For biological graft integration, it is important to provide a physiologically feasible environment for the host cells to enable them to perform their duties. However, behavior of cells during ACL healing and the mechanism of ACL healing is not fully understood partly due to the absence of appropriate environment to test cell behavior both in vitro and in vivo. This study aims at (i) investigating the change in fibril diameter of bovine ACL tissue upon injury and (ii) fabricating nanofiber-based scaffolds to represent the morphology and structure of healthy and injured ACL tissues. We hypothesized that distribution and mean diameter of ACL fibrils will be altered upon injury. Findings revealed that the collagen fibril diameter distribution of bovine ACL changed from bimodal to unimodal upon injury with subsequent decrease in mean diameter. Polycaprolactone (PCL) scaffold fiber diameter distribution exhibited similar bimodal and unimodal distribution behavior to qualitatively represent the cases of healthy and injured ACL, respectively. The native ACL tissue demonstrated comparable modulus values only with the aligned bimodal PCL scaffolds. There was significant difference between mechanical properties of aligned bimodal and unaligned unimodal PCL scaffolds. We believe that the results obtained from measurements of diameter of collagen fibrils of native bovine ACL tissue can serve as a benchmark for scaffold design.
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Roman Regueros, Sabiniano, Maarten Albersen, Stefano Manodoro, Silvia Zia, Nadir I. Osman, Anthony J. Bullock, Christopher R. Chapple, Jan Deprest, and Sheila MacNeil. "AcuteIn VivoResponse to an Alternative Implant for Urogynecology." BioMed Research International 2014 (2014): 1–10. http://dx.doi.org/10.1155/2014/853610.
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Purpose. To investigatein vivothe acute host response to an alternative implant designed for the treatment of stress urinary incontinence (SUI) and pelvic organ prolapse (POP).Methods. A biodegradable scaffold was produced from poly-L-lactic acid (PLA) using the electrospinning technique. Human and rat adipose-derived stem cells (ADSCs) were isolated and characterized by fluorescence-activated cell sorting and differentiation assays. PLA scaffolds were seeded and cultured for 2 weeks with human or rat ADSCs. Scaffolds with and without human or rat ADSCs were implanted subcutaneously on the abdominal wall of rats. After 3 and 7 days, 6 animals from each group were sacrificed. Sections from each sample were analyzed by Haematoxylin and Eosin staining, Sirius red staining, and immunohistochemistry for CD68, PECAM-1, and collagen I and III.Results. Animals responded to the scaffolds with an acute macrophage response. After 7 days of implantation, there was extensive host cell penetration, new blood vessel formation, and new collagen deposition throughout the full thickness of the samples without obvious differences between cell-containing and cell-free scaffolds.Conclusions. The acutein vivoresponse to an alternative implant (both with and without cells) for the treatment of SUI and POP showed good acute integration into the host tissues.
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CHANG, CHIH-HUNG, CHIEN-CHENG LIN, CHENG-HUNG CHOU, FENG-HUEI LIN, and HWA-CHANG LIU. "NOVEL BIOREACTORS FOR OSTEOCHONDRAL TISSUE ENGINEERING." Biomedical Engineering: Applications, Basis and Communications 17, no. 01 (February 25, 2005): 38–43. http://dx.doi.org/10.4015/s101623720500007x.
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Tissue engineering is a new approach for articular cartilage repair, but the integration of engineered cartilage into the host subchondral bone is a major problem. One approach for solving this problem is to make osteochondral tissue engineering instead of cartilage tissue engineering only. The aim of the present paper was to describe two patented newly designed bioreactors for tissue-engineered osteochondral graft. The first bioreactor is double-chamber bioreactor, which is made of glass and is completely transparent. The whole system consists of one chamber for culture of chondrocytes and the other chamber for osteoblast culture. One important role for this bioreactor is to co-culture osteoblasts and chondrocytes at the same time in a biphasic scaffold. The bioreactor is modified from spinner flasks. The stirring of the magnetic bars provides medium mixing and mechanical stimulations for the cells. The second bioreactor is modified from perfusion chamber. The driven force of the medium flow is produced by siphon phenomenon. The bioreactor is composed with two parts. The first part is a modified siphon tube which can hold the biphasic scaffold for osteochondral tissue engineering. The second part is a medium reservoir bottle, which contains large amount of medium and can connect to multiple siphon tubes at the same time. The medium reservoir bottle is placed higher than the siphon tubes. The gravity will drive medium into the siphon tubes. The siphon phenomenon will make the cell-seeded scaffold covered with the medium. When the height of medium reach the height of outflow tube of the siphon tube, the medium will drain out, and the scaffold will be exposed to the air in incubator, which provides oxygen exposure. Then the gravity will make the medium refill again, the scaffold will be immersed in medium until next cycle of medium drainage out. The curve shape of the siphon tube will prevent backward bacteria contamination. The flow of the medium from reservoir through the siphon tube will produce an effect like traditional perfusion chamber bioreactor; however no power supply is necessary in this system.
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Tian, T., T. Zhang, Y. Lin, and X. Cai. "Vascularization in Craniofacial Bone Tissue Engineering." Journal of Dental Research 97, no. 9 (April 2, 2018): 969–76. http://dx.doi.org/10.1177/0022034518767120.
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Craniofacial bones, separate from the appendicular skeleton, bear a significant amount of strain and stress generated from mastication-related muscles. Current research on the regeneration of craniofacial bone focuses on the reestablishment of an elaborate vascular network. In this review, current challenges and efforts particularly in advances of scaffold properties and techniques for vascularization remodeling in craniofacial bone tissue engineering will be discussed. A microenvironment of ischemia and hypoxia in the biomaterial core drives propagation and reorganization of endothelial progenitor cells (EPCs) to assemble into a primitive microvascular framework. Co-culture strategies and delivery of vasculogenic molecules enhance EPCs’ differentiation and stimulate the host regenerative response to promote vessel sprouting and strength. To optimize structural and vascular integration, well-designed microstructures of scaffolds are biologically considered. Proper porous structures, matrix stiffness, and surface morphology of scaffolds have a profound influence on cell behaviors and thus affect revascularization. In addition, advanced techniques facilitating angiogenesis and vaculogenesis have also been discussed. Oxygen delivery biomaterials, scaffold-free cell sheet techniques, and arteriovenous loop-induced axial vascularization strategies bring us new understanding and powerful strategies to manage revascularization of large craniofacial bone defects. Although promising histological results have been achieved, the efficient perfusion and functionalization of newly formed vessels are still challenging.
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Riewruja, Kanyakorn, Alyssa M. Aguglia, Sophie Hines, Meagan J. Makarcyzk, Sittisak Honsawek, and Hang Lin. "PEG Reinforced Scaffold Promotes Uniform Distribution of Human MSC-Created Cartilage Matrix." Gels 8, no. 12 (December 3, 2022): 794. http://dx.doi.org/10.3390/gels8120794.
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Previously, we used a gelatin/hyaluronic acid (GH)-based scaffold to induce chondrogenic differentiation of human bone marrow-derived mesenchymal stromal cells (hBMSC). The results showed that hBMSCs underwent robust chondrogenesis and facilitated in vivo cartilage regeneration. However, it was noticed that the GH scaffolds display a compressive modulus that is markedly lower than native cartilage. In this study, we aimed to enhance the mechanical strength of GH scaffolds without significantly impairing their chondrosupportive property. Specifically, polyethylene glycol diacrylate (PEGDA) and photoinitiators were infiltrated into pre-formed hBMSC-laden GH scaffolds and then photo-crosslinked. Results showed that infiltration of PEG at the beginning of chondrogenesis significantly increased the deposition of glycosaminoglycans (GAGs) in the central area of the scaffold. To explore the mechanism, we compared the cell migration and proliferation in the margin and central areas of GH and PEG-infiltrated GH scaffolds (GH+PEG). Limited cell migration was noticed in both groups, but more proliferating cells were observed in GH than in GH+PEG. Lastly, the in vitro repairing study with bovine cartilage explants showed that PEG- impregnated scaffolds integrated well with host tissues. These results indicate that PEG-GH hybrid scaffolds, created through infiltrating PEG into pre-formed GH scaffolds, display good integration capacity and represent a new tool for the repair of chondral injury.
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Ruzicka, Jiri, Nataliya Romanyuk, Klara Jirakova, Ales Hejcl, Olga Janouskova, Lucia Urdzikova Machova, Marcel Bochin, Martin Pradny, Lydia Vargova, and Pavla Jendelova. "The Effect of iPS-Derived Neural Progenitors Seeded on Laminin-Coated pHEMA-MOETACl Hydrogel with Dual Porosity in a Rat Model of Chronic Spinal Cord Injury." Cell Transplantation 28, no. 4 (January 18, 2019): 400–412. http://dx.doi.org/10.1177/0963689718823705.
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Spinal cord injury (SCI), is a devastating condition leading to the loss of locomotor and sensory function below the injured segment. Despite some progress in acute SCI treatment using stem cells and biomaterials, chronic SCI remains to be addressed. We have assessed the use of laminin-coated hydrogel with dual porosity, seeded with induced pluripotent stem cell-derived neural progenitors (iPSC-NPs), in a rat model of chronic SCI. iPSC-NPs cultured for 3 weeks in hydrogel in vitro were positive for nestin, glial fibrillary acidic protein (GFAP) and microtubule-associated protein 2 (MAP2). These cell-polymer constructs were implanted into a balloon compression lesion, 5 weeks after lesion induction. Animals were behaviorally tested, and spinal cord tissue was immunohistochemically analyzed 28 weeks after SCI. The implanted iPSC-NPs survived in the scaffold for the entire experimental period. Host axons, astrocytes and blood vessels grew into the implant and an increased sprouting of host TH+ fibers was observed in the lesion vicinity. The implantation of iPSC-NP-LHM cell-polymer construct into the chronic SCI led to the integration of material into the injured spinal cord, reduced cavitation and supported the iPSC-NPs survival, but did not result in a statistically significant improvement of locomotor recovery.
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Gu, Ben Jiahe, Dennis Jgamadze, Guoming (Tony) Man, and Han-Chiao Isaac Chen. "4418 Optimization and Validation of a Silk Scaffold-Based Neural Tissue Construct." Journal of Clinical and Translational Science 4, s1 (June 2020): 13–14. http://dx.doi.org/10.1017/cts.2020.85.
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OBJECTIVES/GOALS: Our goal is to develop a silk fibroin scaffold-based neural tissue construct and characterize it in a rat model of cortical injury. We aim to optimize the construct for transplantation, test pharmacologic interventions that may enhance its survival, and evaluate its integration with the host brain. METHODS/STUDY POPULATION: To optimize cell density and health, silk fibroin scaffolds varying in porosity and stiffness were seeded with E18 GFP+ rat cortical neurons and imaged at DIV 5. Different seeding methods and loads were similarly tested. Constructs, loaded with an inhibitor of apoptosis (ROCK inhibitor Y-27632) or necroptosis (necrostatin-1) in a fibrin hydrogel, were transplanted into aspiration lesions created in the primary motor cortex of Sprague-Dawley rats, and graft survival was compared to negative control at 2 weeks. Lastly, constructs were transplanted and evaluated via immunohistochemistry at 1, 2, and 4-month time points for survival, differentiation, inflammation, and anatomic integration. RESULTS/ANTICIPATED RESULTS: Scaffolds with smaller pore sizes retained more cells after seeding. Softer scaffolds, which enhance hemostasis at transplantation, did not compromise cell health on live/dead assay. We anticipate that seeding concentrated cell suspensions onto multiple surfaces of the construct will produce the most evenly seeded and cell-dense constructs. Based on a prior pilot study, we anticipate that necrostatin-1 will significantly improve intermediate-term construct survival. We have observed up to 15% cell survival at 1 month with retained neuronal identity and abundant axonal projections into the brain despite evidence of persistent inflammation; we anticipate similar outcomes at later time points. DISCUSSION/SIGNIFICANCE OF IMPACT: Our construct, due to its exceptional longevity in vitro, manipulability, and modularity, is an attractive platform for neural tissue engineering. In the present work, we optimize and validate this technology for transplantation with the goal of addressing the morbidity burden of cortical injury.
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Kosinski, Michal, Anna Figiel-Dabrowska, Wioletta Lech, Lukasz Wieprzowski, Ryszard Strzalkowski, Damian Strzemecki, Lukasz Cheda, Jacek Lenart, Krystyna Domanska-Janik, and Anna Sarnowska. "Bone Defect Repair Using a Bone Substitute Supported by Mesenchymal Stem Cells Derived from the Umbilical Cord." Stem Cells International 2020 (March 18, 2020): 1–15. http://dx.doi.org/10.1155/2020/1321283.
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Objective. Bone defects or atrophy may arise as a consequence of injury, inflammation of various etiologies, and neoplastic or traumatic processes or as a result of surgical procedures. Sometimes the regeneration process of bone loss is impaired, significantly slowed down, or does not occur, e.g., in congenital defects. For the bone defect reconstruction, a piece of the removed bone from ala of ilium or bone transplantation from a decedent is used. Replacement of the autologous or allogenic source of the bone-by-bone substitute could reduce the number of surgeries and time in the pharmacological coma during the reconstruction of the bone defect. Application of mesenchymal stem cells in the reconstruction surgery may have positive influence on tissue regeneration by secretion of angiogenic factors, recruitment of other MSCs, or differentiation into osteoblasts. Materials and Methods. Mesenchymal stem cells derived from the umbilical cord (Wharton’s jelly (WJ-MSC)) were cultured in GMP-grade DMEM low glucose supplemented with heparin, 10% platelet lysate, glucose, and antibiotics. In vitro WJ-MSCs were seeded on the bone substitute Bio-Oss Collagen® and cultured in the StemPro® Osteogenesis Differentiation Kit. During the culture on the 1st, 7th, 14th, and 21st day (day in vitro (DIV)), we analyzed viability (confocal microscopy) and adhesion capability (electron microscopy) of WJ-MSC on Bio-Oss scaffolds, gene expression (qPCR), and secretion of proteins (Luminex). In vivo Bio-Oss® scaffolds with WJ-MSC were transplanted to trepanation holes in the cranium to obtain their overgrowth. The computed tomography was performed 7, 14, and 21 days after surgery to assess the regeneration. Results. The Bio-Oss® scaffold provides a favourable environment for WJ-MSC survival. WJ-MSCs in osteodifferentiation medium are able to attach and proliferate on Bio-Oss® scaffolds. Results obtained from qPCR and Luminex® indicate that WJ-MSCs possess the ability to differentiate into osteoblast-like cells and may induce osteoclastogenesis, angiogenesis, and mobilization of host MSCs. In animal studies, WJ-MSCs seeded on Bio-Oss® increased the scaffold integration with host bone and changed their morphology to osteoblast-like cells. Conclusions. The presented construct consisted of Bio-Oss®, the scaffold with high flexibility and plasticity, approved for clinical use with seeded immunologically privileged WJ-MSC which may be considered reconstructive therapy in bone defects.
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Bonfield, William. "Designing porous scaffolds for tissue engineering." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 364, no. 1838 (November 29, 2005): 227–32. http://dx.doi.org/10.1098/rsta.2005.1692.
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Biomaterials are either modified natural or synthetic materials, with an appropriate response in the host tissue, which find application in a wide spectrum of implants and prostheses used in reconstructive medicine. The subsequent integration and longevity of the implanted device depends on the effectiveness of the associated biological repair. Hence, there has been considerable interest in the development of novel, second generation, biomaterials, which are favourably bioactive in terms of promoting the desired cellular response in vivo . Such biomaterials in a porous form can also act as cellular scaffolds and allow in vitro , as well as in vivo incorporation of the appropriate tissue cells, with potential control of the sequence of cell attachment, proliferation and the production of extra-cellular matrix. Such generic tissue engineering depends critically on the porous architecture of the biomaterial scaffold so as to allow both the cellular ingress and vascularization required to create a living tissue. The particular requirements of tissue-engineering scaffolds with respect to macro- and micro-porosity, as well as chemistry, are reviewed.
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Tonietto, Leonardo, Andres F. Vasquez, Luís A. dos Santos, and João BB Weber. "Histological and structural evaluation of growth hormone and PLGA incorporation in macroporous scaffold of α-tricalcium phosphate cement." Journal of Biomaterials Applications 33, no. 6 (November 14, 2018): 866–75. http://dx.doi.org/10.1177/0885328218812173.
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An in vivo study was conducted to evaluate the effects of the incorporation of fibers of poly(lactic acid-co-glycolic acid, PLGA) and poly(isoprene) blend and recombinant human growth hormone (rhGH) in a macroporous scaffold of α-tricalcium phosphate cement (α-TCP) samples inserted into calvarial defects (8 mm in diameter) of 48 Wistar rats. The samples of α-TCP + PLGA/poly(isoprene) blend fibers were also submitted to a mechanical test of flexural strength. The animals of the different experimental groups [1] α-TCP (n = 6); [2] α-TCP + PLGA/poly(isoprene) blend fibers (n = 6); [3] α-TCP + rhGH, (n = 6) and [4] α-TCP + PLGA/poly(isoprene) blend fibers + rhGH, (n = 6) (the numbers within square brackets identify the experimental groups), after two weeks (subdivision “a”) and four weeks (subdivision “b”), were euthanized and the implants removed for histological analysis. There was no statistical difference (p > 0.05) between the samples with and without fibers in the mechanical test. Light microscopy revealed good integration of the material in the host tissue, represented by tissue penetration into the macropores and adequate angiogenesis. In the two-week period, the groups [3a] and [4a] were significantly superior (p < 0.05) to the other groups with regard to angiogenesis and bone neoformation. In the four-week period, the group [3b] was significantly superior (p < 0.05) to the other groups with regard to bone neoformation. We conclude that the macroporous α-TCP scaffold used in this study has low mechanical resistance, is biocompatible and has significantly improved the osteoconductive capacity when rhGH is incorporated into its structure.
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Alvarado-Hidalgo, Fernando, Karla Ramírez-Sánchez, and Ricardo Starbird-Perez. "Smart Porous Multi-Stimulus Polysaccharide-Based Biomaterials for Tissue Engineering." Molecules 25, no. 22 (November 13, 2020): 5286. http://dx.doi.org/10.3390/molecules25225286.
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Recently, tissue engineering and regenerative medicine studies have evaluated smart biomaterials as implantable scaffolds and their interaction with cells for biomedical applications. Porous materials have been used in tissue engineering as synthetic extracellular matrices, promoting the attachment and migration of host cells to induce the in vitro regeneration of different tissues. Biomimetic 3D scaffold systems allow control over biophysical and biochemical cues, modulating the extracellular environment through mechanical, electrical, and biochemical stimulation of cells, driving their molecular reprogramming. In this review, first we outline the main advantages of using polysaccharides as raw materials for porous scaffolds, as well as the most common processing pathways to obtain the adequate textural properties, allowing the integration and attachment of cells. The second approach focuses on the tunable characteristics of the synthetic matrix, emphasizing the effect of their mechanical properties and the modification with conducting polymers in the cell response. The use and influence of polysaccharide-based porous materials as drug delivery systems for biochemical stimulation of cells is also described. Overall, engineered biomaterials are proposed as an effective strategy to improve in vitro tissue regeneration and future research directions of modified polysaccharide-based materials in the biomedical field are suggested.
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Vasileva, Radina, and Tzvetan Chaprazov. "Bone Healing of Critical-Sized Femoral Defects in Rats Treated with Erythropoietin Alone or in Combination with Xenograft." Veterinary Sciences 10, no. 3 (March 5, 2023): 196. http://dx.doi.org/10.3390/vetsci10030196.
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Critical-size bone defect models are the standard in studies of the osteogenic potential of biomaterials. The present investigation aimed to evaluate the ability of recombinant human erythropoietin (EPO) to induce trabecular bone healing either alone or combined with a xenograft in a rat femoral critical-size defect model. Five-mm bone defects were created in the femoral diaphysis of fifty-six skeletally mature male Wistar albino rats. The animals were divided into six groups: one control group and five experimental groups. The defects in the control group were left empty, whereas an absorbable collagen cone soaked either with saline or erythropoietin (alone or in combination with xenograft) was placed in locally treated groups. The systemic treatment group received EPO subcutaneously. Bone formation was objectively evaluated through radiography, osteodensitometry and histological examination on post-operative days 30 and 90. The results demonstrate that EPO, locally applied on a collagen scaffold, was capable of inducing bone healing, whereas the single systemically administered high EPO dose had only an insignificant effect on bone formation. The combination of EPO with a bone substitute under the form of cancellous granules resulted in more rapid integration between the xenograft and host bone.
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Mancuso, Antonia, Antonella Barone, Maria Chiara Cristiano, Eleonora Cianflone, Massimo Fresta, and Donatella Paolino. "Cardiac Stem Cell-Loaded Delivery Systems: A New Challenge for Myocardial Tissue Regeneration." International Journal of Molecular Sciences 21, no. 20 (October 18, 2020): 7701. http://dx.doi.org/10.3390/ijms21207701.
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Cardiovascular disease (CVD) remains the leading cause of death in Western countries. Post-myocardial infarction heart failure can be considered a degenerative disease where myocyte loss outweighs any regenerative potential. In this scenario, regenerative biology and tissue engineering can provide effective solutions to repair the infarcted failing heart. The main strategies involve the use of stem and progenitor cells to regenerate/repair lost and dysfunctional tissue, administrated as a suspension or encapsulated in specific delivery systems. Several studies demonstrated that effectiveness of direct injection of cardiac stem cells (CSCs) is limited in humans by the hostile cardiac microenvironment and poor cell engraftment; therefore, the use of injectable hydrogel or pre-formed patches have been strongly advocated to obtain a better integration between delivered stem cells and host myocardial tissue. Several approaches were used to refine these types of constructs, trying to obtain an optimized functional scaffold. Despite the promising features of these stem cells’ delivery systems, few have reached the clinical practice. In this review, we summarize the advantages, and the novelty but also the current limitations of engineered patches and injectable hydrogels for tissue regenerative purposes, offering a perspective of how we believe tissue engineering should evolve to obtain the optimal delivery system applicable to the everyday clinical scenario.
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Talsania, Keyur, Monika Mehta, Castle Raley, Yuliya Kriga, Sujatha Gowda, Carissa Grose, Matthew Drew, et al. "Genome Assembly and Annotation of the Trichoplusia ni Tni-FNL Insect Cell Line Enabled by Long-Read Technologies." Genes 10, no. 2 (January 23, 2019): 79. http://dx.doi.org/10.3390/genes10020079.
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Background: Trichoplusia ni derived cell lines are commonly used to enable recombinant protein expression via baculovirus infection to generate materials approved for clinical use and in clinical trials. In order to develop systems biology and genome engineering tools to improve protein expression in this host, we performed de novo genome assembly of the Trichoplusia ni-derived cell line Tni-FNL. Methods: By integration of PacBio single-molecule sequencing, Bionano optical mapping, and 10X Genomics linked-reads data, we have produced a draft genome assembly of Tni-FNL. Results: Our assembly contains 280 scaffolds, with a N50 scaffold size of 2.3 Mb and a total length of 359 Mb. Annotation of the Tni-FNL genome resulted in 14,101 predicted genes and 93.2% of the predicted proteome contained recognizable protein domains. Ortholog searches within the superorder Holometabola provided further evidence of high accuracy and completeness of the Tni-FNL genome assembly. Conclusions: This first draft Tni-FNL genome assembly was enabled by complementary long-read technologies and represents a high-quality, well-annotated genome that provides novel insight into the complexity of this insect cell line and can serve as a reference for future large-scale genome engineering work in this and other similar recombinant protein production hosts.
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Lawson, Jeffrey. "Engineered Blood Vessels." Blood 130, Suppl_1 (December 7, 2017): SCI—12—SCI—12. http://dx.doi.org/10.1182/blood.v130.suppl_1.sci-12.sci-12.
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Abstract The field of tissue engineering has has made significant progress in the past 20 years. Of the many tissues and organs in development, the area of vascular tissue engineering is now one of the most mature. In that regard, we have developed a novel tissue engineered vascular graft (human acellular vessel [HAV]) that addresses many of the limitations of native vein harvest and the performance of both synthetic ePTFE and autologous vein grafts. The HAV is manufactured in a laboratory by culturing human vascular cells within a biodegradable scaffold that forms a mechanically robust tissue engineered blood vessel. The cells are then completely removed (decellularization), leaving behind a non-immunogenic human collagen-based vascular tissue that can be stored on the shelf for months at a time and ready for immediate implantation into any patient. The HAV is currently being evaluated in Phase II and Phase III clinical trials in the U.S., E.U. and Israel as an arteriovenous vascular access graft for hemodialysis in patients with end-stage renal failure and as an arterial substitute for patients in need of vascular bypass for peripheral arterial disease or vascular trauma. Following clinical implantation, we have observed repopulation and remodeling of the manufactured vessel with the hosts' own cells. We hypothesize that the biological composition of the HAV, compared to synthetic vascular grafts, promotes its physiological integration into host tissue including support of normal host cell infiltration and function. Host cells that identify histologically similar to vascular smooth muscle cells appear to repopulate the middle of the vessel and recipient cells characterized as endothelial cells appear to cover the luminal surface of the implanted vessel. Clinical observations of the Phase II trials have demonstrated excellent vessel durability and a freedom from both early and delayed infection. Based on the success of the Phase II studies, a Global Phase III study is underway for patients in need of dialysis access shunts and vascular programs for vascular (arterial) bypass and trauma are expanding. Disclosures Lawson: InnaVasc: Patents & Royalties; Humacyte, Inc.: Employment.
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Fang, Hsu-Wei. "TRENDS AND CHALLENGES OF CARTILAGE TISSUE ENGINEERING." Biomedical Engineering: Applications, Basis and Communications 21, no. 03 (June 2009): 149–55. http://dx.doi.org/10.4015/s1016237209001209.
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Cartilage injuries may be caused by trauma, biomechanical imbalance, or degenerative changes of joint. Unfortunately, cartilage has limited capability to spontaneous repair once damaged and may lead to progressive damage and degeneration. Cartilage tissue-engineering techniques have emerged as the potential clinical strategies. An ideal tissue-engineering approach to cartilage repair should offer good integration into both the host cartilage and the subchondral bone. Cells, scaffolds, and growth factors make up the tissue engineering triad. One of the major challenges for cartilage tissue engineering is cell source and cell numbers. Due to the limitations of proliferation for mature chondrocytes, current studies have alternated to use stem cells as a potential source. In the recent years, a lot of novel biomaterials has been continuously developed and investigated in various in vitro and in vivo studies for cartilage tissue engineering. Moreover, stimulatory factors such as bioactive molecules have been explored to induce or enhance cartilage formation. Growth factors and other additives could be added into culture media in vitro, transferred into cells, or incorporated into scaffolds for in vivo delivery to promote cellular differentiation and tissue regeneration.Based on the current development of cartilage tissue engineering, there exist challenges to overcome. How to manipulate the interactions between cells, scaffold, and signals to achieve the moderation of implanted composite differentiate into moderate stem cells to differentiate into hyaline cartilage to perform the optimum physiological and biomechanical functions without negative side effects remains the target to pursue.
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Fan, Hongbin, Haifeng Liu, Rui Zhu, Xusheng Li, Yuming Cui, Yunyu Hu, and Yongnian Yan. "Comparison of Chondral Defects Repair with In Vitro and In Vivo Differentiated Mesenchymal Stem Cells." Cell Transplantation 16, no. 8 (September 2007): 823–32. http://dx.doi.org/10.3727/000000007783465181.
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The purpose of this study was to compare chondral defects repair with in vitro and in vivo differentiated mesenchymal stem cells (MSCs). A novel PLGA-gelatin/chondroitin/hyaluronate (PLGA-GCH) hybrid scaffold with transforming growth factor-β1 (TGF-β1)-impregnated microspheres (MS-TGF) was fabricated to mimic the extracellular matrix. MS-TGF showed an initial burst release (22.5%) and a subsequent moderate one that achieved 85.1% on day 21. MSCs seeded on PLGA-GCH/MS-TGF or PLGA-GCH were incubated in vitro and showed that PLGA-GCH/MS-TGF significantly augmented proliferation of MSCs and glycosaminoglycan synthesis compared with PLGA-GCH. Then MSCs seeded on PLGA-GCH/MS-TGF were implanted and differentiated in vivo to repair chondral defect on the right knee of rabbit (in vivo differentiation repair group), while the contralateral defect was repaired with in vitro differentiated MSCs seeded on PLGA-GCH (in vitro differentiation repair group). The histology observation demonstrated that in vivo differentiation repair showed better chondrocyte morphology, integration, and subchondral bone formation compared with in vitro differentiation repair 12 and 24 weeks postoperatively, although there was no significant difference after 6 weeks. The histology grading score comparison also demonstrated the same results. The present study implies that in vivo differentiation induced by PLGA-GCH/MS-TGF and the host microenviroment could keep chondral phenotype and enhance repair. It might serve as another way to induce and expand seed cells in cartilage tissue engineering.
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Lua, B. L., and B. C. Low. "Filling the GAPs in cell dynamics control: BPGAP1 promotes cortactin translocation to the cell periphery for enhanced cell migration." Biochemical Society Transactions 32, no. 6 (October 26, 2004): 1110–12. http://dx.doi.org/10.1042/bst0321110.
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Cells undergo dynamic changes in morphology or motility during cellular division and proliferation, differentiation, neuronal pathfinding, wound healing, apoptosis, host defense and organ development. These processes are controlled by signalling events relayed through cascades of protein interactions leading to the establishment and maintenance of cytoskeletal networks of microtubules and actin. Various regulators, including the Rho small GTPases (guanine nucleotide triphosphatases), serve as master switches to fine-tune the amplitude, duration as well as the integration of such circuitry responses. Rho GTPases are activated by guanine nucleotide-exchange factors and inactivated by GAPs (GTPase-activating proteins). Although normally down-regulating signalling pathways by catalysing their GTPase activity, many GAPs exist with various protein modules, the functions of which still largely remain unknown. BPGAP1 is a novel RhoGAP that co-ordinately regulates pseudopodia and cell migration through the interplay of its BNIP-2 and Cdc42GAP homology domains serving as a homophilic/heterophilic interaction device, an enzymic RhoGAP domain that inactivates RhoA and a proline-rich region that binds the Src homology-3 domain of cortactin. Both proteins co-localize to cell periphery and enhance cell migration. As a molecular scaffold in cortical actin assembly and organization, cortactin and its interaction with small GTPases, GAPs and tyrosine kinases seems set to provide further insights to the multiplicity and complexity of cell dynamics control. Elucidating how these processes might be individually or co-ordinately regulated through cortactin remains an exciting future challenge.
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Han, Ian C., Laura R. Bohrer, Katherine N. Gibson-Corley, Luke A. Wiley, Arwin Shrestha, Brynnon E. Harman, Chunhua Jiao, et al. "Biocompatibility of Human Induced Pluripotent Stem Cell–Derived Retinal Progenitor Cell Grafts in Immunocompromised Rats." Cell Transplantation 31 (January 2022): 096368972211044. http://dx.doi.org/10.1177/09636897221104451.
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Loss of photoreceptor cells is a primary feature of inherited retinal degenerative disorders including age-related macular degeneration and retinitis pigmentosa. To restore vision in affected patients, photoreceptor cell replacement will be required. The ideal donor cells for this application are induced pluripotent stem cells (iPSCs) because they can be derived from and transplanted into the same patient obviating the need for long-term immunosuppression. A major limitation for retinal cell replacement therapy is donor cell loss associated with simple methods of cell delivery such as subretinal injections of bolus cell suspensions. Transplantation with supportive biomaterials can help maintain cellular integrity, increase cell survival, and encourage proper cellular alignment and improve integration with the host retina. Using a pig model of retinal degeneration, we recently demonstrated that polycaprolactone (PCL) scaffolds fabricated with two photon lithography have excellent local and systemic tolerability. In this study, we describe rapid photopolymerization-mediated production of PCL-based bioabsorbable scaffolds, a technique for loading iPSC-derived retinal progenitor cells onto the scaffold, methods of surgical transplantation in an immunocompromised rat model and tolerability of the subretinal grafts at 1, 3, and 6 months of follow-up ( n = 150). We observed no local or systemic toxicity, nor did we observe any tumor formation despite extensive clinical evaluation, clinical chemistry, hematology, gross tissue examination and detailed histopathology. Demonstrating the local and systemic compatibility of biodegradable scaffolds carrying human iPSC-derived retinal progenitor cells is an important step toward clinical safety trials of this approach in humans.
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Litak, Jakub, Wojciech Czyzewski, Michał Szymoniuk, Bartlomiej Pastuszak, Joanna Litak, Grzegorz Litak, Cezary Grochowski, Mansur Rahnama-Hezavah, and Piotr Kamieniak. "Hydroxyapatite Use in Spine Surgery—Molecular and Clinical Aspect." Materials 15, no. 8 (April 15, 2022): 2906. http://dx.doi.org/10.3390/ma15082906.
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Hydroxyapatite possesses desirable properties as a scaffold in tissue engineering: it is biocompatible at a site of implantation, and it is degradable to non-toxic products. Moreover, its porosity enables infiltration of cells, nutrients and waste products. The outcome of hydroxyapatite implantation highly depends on the extent of the host immune response. Authors emphasise major roles of the chemical, morphological and physical properties of the surface of biomaterial used. A number of techniques have been applied to transform the theoretical osteoconductive features of HAp into spinal fusion systems—from integration of HAp with autograft to synthetic intervertebral implants. The most popular uses of HAp in spine surgery include implants (ACDF), bone grafts in posterolateral lumbar fusion and transpedicular screws coating. In the past, autologous bone graft has been used as an intervertebral cage in ACDF. Due to the morbidity related to autograft harvesting from the iliac bone, a synthetic cage with osteoconductive material such as hydroxyapatite seems to be a good alternative. Regarding posterolateral lumbar fusion, it requires the graft to induce new bone growth and reinforce fusion between the vertebrae. Hydroxyapatite formulations have shown good results in that field. Moreover, the HAp coating has proven to be an efficient method of increasing screw fixation strength. It can decrease the risk of complications such as screw loosening after pedicle screw fixation in osteoporotic patients. The purpose of this literature review is to describe in vivo reaction to HAp implants and to summarise its current application in spine surgery.
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Saunders, Sarah K., Sam Y. Cole, Valeria Acuna Sierra, Johane H. Bracamonte, Stefano Toldo, and Joao S. Soares. "Evaluation of perfusion-driven cell seeding of small diameter engineered tissue vascular grafts with a custom-designed seed-and-culture bioreactor." PLOS ONE 17, no. 6 (June 16, 2022): e0269499. http://dx.doi.org/10.1371/journal.pone.0269499.
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Tissue engineering commonly entails combining autologous cell sources with biocompatible scaffolds for the replacement of damaged tissues in the body. Scaffolds provide functional support while also providing an ideal environment for the growth of new tissues until host integration is complete. To expedite tissue development, cells need to be distributed evenly within the scaffold. For scaffolds with a small diameter tubular geometry, like those used for vascular tissue engineering, seeding cells evenly along the luminal surface can be especially challenging. Perfusion-based cell seeding methods have been shown to promote increased uniformity in initial cell distribution onto porous scaffolds for a variety of tissue engineering applications. We investigate the seeding efficiency of a custom-designed perfusion-based seed-and-culture bioreactor through comparisons to a static injection counterpart method and a more traditional drip seeding method. Murine vascular smooth muscle cells were seeded onto porous tubular electrospun polycaprolactone scaffolds, 2 mm in diameter and 30 mm in length, using the three methods, and allowed to rest for 24 hours. Once harvested, scaffolds were evaluated longitudinally and circumferentially to assess the presence of viable cells using alamarBlue and live/dead cell assays and their distribution with immunohistochemistry and scanning electron microscopy. On average, bioreactor-mediated perfusion seeding achieved 35% more luminal surface coverage when compared to static methods. Viability assessment demonstrated that the total number of viable cells achieved across methods was comparable with slight advantage to the bioreactor-mediated perfusion-seeding method. The method described is a simple, low-cost method to consistently obtain even distribution of seeded cells onto the luminal surfaces of small diameter tubular scaffolds.
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Schmidt, Thomas, Charles D. Schwieters, and G. Marius Clore. "Spatial domain organization in the HIV-1 reverse transcriptase p66 homodimer precursor probed by double electron-electron resonance EPR." Proceedings of the National Academy of Sciences 116, no. 36 (August 5, 2019): 17809–16. http://dx.doi.org/10.1073/pnas.1911086116.
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HIV type I (HIV-1) reverse transcriptase (RT) catalyzes the conversion of viral RNA into DNA, initiating the chain of events leading to integration of proviral DNA into the host genome. RT is expressed as a single polypeptide chain within the Gag-Pol polyprotein, and either prior to or following excision by HIV-1 protease forms a 66 kDa chain (p66) homodimer precursor. Further proteolytic attack by HIV-1 protease cleaves the ribonuclease H (RNase H) domain of a single subunit to yield the mature p66/p51 heterodimer. Here, we probe the spatial domain organization within the p66 homodimer using pulsed Q-band double electron-electron resonance (DEER) EPR spectroscopy to measure a large number of intra- and intersubunit distances between spin labels attached to surface-engineered cysteines. The DEER-derived distances are fully consistent with the structural subunit asymmetry found in the mature p66/p51 heterodimer in which catalytic activity resides in the p66 subunit, while the p51 subunit purely serves as a structural scaffold. Furthermore, the p66 homodimer precursor undergoes a conformational change involving the thumb, palm, and finger domains in one of the subunits (corresponding to the p66 subunit in the mature p66/p51 heterodimer) from a closed to a partially open state upon addition of a nonnucleoside inhibitor. The relative orientation of the domains was modeled by simulated annealing driven by the DEER-derived distances. Finally, the RNase H domain that is cleaved to generate p51 in the mature p66/p51 heterodimer is present in 2 major conformers. One conformer is fully solvent accessible thereby accounting for the observation that only a single subunit of the p66 homodimer precursor is susceptible to HIV-1 protease.
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Tate, Matthew C., Deborah A. Shear, Stuart W. Hoffman, Donald G. Stein, David R. Archer, and Michelle C. Laplaca. "Fibronectin Promotes Survival and Migration of Primary Neural Stem Cells Transplanted into the Traumatically Injured Mouse Brain." Cell Transplantation 11, no. 3 (April 2002): 283–95. http://dx.doi.org/10.3727/096020198389933.
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Multipotential stem cells are an attractive choice for cell therapy after traumatic brain injury (TBI), as replacement of multiple cell types may be required for functional recovery. In the present study, neural stem cells (NSCs) derived from the germinal zone of E14.5 GFP-expressing mouse brains were cultured as neurospheres in FGF2-enhanced medium. When FGF2 was removed in vitro, NSCs expressed phenotypic markers for neurons, astrocytes, and oligodendrocytes and exhibited migratory behavior in the presence of adsorbed fibronectin (FN). NSCs (105 cells) were transplanted into mouse brains 1 week after a unilateral, controlled, cortical contusion (depth = 1 mm, velocity = 6 m/s, duration = 150 ms) (n = 19). NSCs were injected either directly into the injury cavity with or without an injectable FN-based scaffold [collagen I (CnI)/ FN gel; n = 14] or into the striatum below the injury cavity (n = 5). At all time points examined (1 week to 3 months posttransplant), GFP+ cells were confined to the ipsilateral host brain tissue. At 1 week, cells injected into the injury cavity lined the injury penumbra while cells inserted directly into the striatum remained in or around the needle track. Striatal transplants had a lower number of surviving GFP+ cells relative to cavity injections at the 1 week time point (p < 0.01). At the longer survival times (3 weeks–3 months), 63–76% of transplanted cells migrated into the fimbria hippocampus regardless of injection site, perhaps due to cues from the degenerating hippocampus. Furthermore, cells injected into the cavity within a FN-containing matrix showed increased survival and migration at 3 weeks (p < 0.05 for both) relative to injections of cells alone. These results suggest that FGF2-responsive NSCs present a promising approach for cellular therapy following trauma and that the transplant location and environment may play an important role in graft survival and integration.
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Storti, Gabriele, Maria Giovanna Scioli, Bong-Sung Kim, Augusto Orlandi, and Valerio Cervelli. "Adipose-Derived Stem Cells in Bone Tissue Engineering: Useful Tools with New Applications." Stem Cells International 2019 (November 6, 2019): 1–18. http://dx.doi.org/10.1155/2019/3673857.
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Adipose stem cells (ASCs) are a crucial element in bone tissue engineering (BTE). They are easy to harvest and isolate, and they are available in significative quantities, thus offering a feasible and valid alternative to other sources of mesenchymal stem cells (MSCs), like bone marrow. Together with an advantageous proliferative and differentiative profile, they also offer a high paracrine activity through the secretion of several bioactive molecules (such as growth factors and miRNAs) via a sustained exosomal release which can exert efficient conditioning on the surrounding microenvironment. BTE relies on three key elements: (1) scaffold, (2) osteoprogenitor cells, and (3) bioactive factors. These elements have been thoroughly investigated over the years. The use of ASCs has offered significative new advancements in the efficacy of each of these elements. Notably, the phenotypic study of ASCs allowed discovering cell subpopulations, which have enhanced osteogenic and vasculogenic capacity. ASCs favored a better vascularization and integration of the scaffolds, while improvements in scaffolds’ materials and design tried to exploit the osteogenic features of ASCs, thus reducing the need for external bioactive factors. At the same time, ASCs proved to be an incredible source of bioactive, proosteogenic factors that are released through their abundant exosome secretion. ASC exosomes can exert significant paracrine effects in the surroundings, even in the absence of the primary cells. These paracrine signals recruit progenitor cells from the host tissues and enhance regeneration. In this review, we will focus on the recent discoveries which have involved the use of ASCs in BTE. In particular, we are going to analyze the different ASCs’ subpopulations, the interaction between ASCs and scaffolds, and the bioactive factors which are secreted by ASCs or can induce their osteogenic commitment. All these advancements are ultimately intended for a faster translational and clinical application of BTE.
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Lee, Jin Woo. "New Perspectives of Osteochondral Lesion of the Talus." Orthopaedic Journal of Sports Medicine 7, no. 11_suppl6 (November 1, 2019): 2325967119S0045. http://dx.doi.org/10.1177/2325967119s00453.
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Osteochondral lesions of the talus(OLT) are the most common articular cartilage defects in the ankle and may cause disability as a result of chronic pain and limited weight-bearing capacity. Numerous treatment strategies for symptomatic OLT have advanced significantly over the past decades. OLT are often managed conservatively for an initial stage before the surgical treatment. However, the conservative management determined solely on symptomatology, and not on the physiological healing. A systematic review for the treatment of OLT demonstrated a 45% success rate of non-operative management. Surgical treatment of OLT is reserved for symptomatic focal lesions that fail to respond to conservative treatments. There are three major operative strategies for OLT, reparative, replacement and regenerative manners. For the reparative modality, arthroscopic bone marrow stimulation(BMS) is widely regarded as the first-line treatment for OLT, as it is a technically undemanding, cost-effective, and minimally invasive procedure with low rates of complication and postoperative pain. Small lesion (<15 mm in diameter or <150mm2 in size) is the ideal candidate for BMS supported by several literatures. And a study reported the long-term follow-up study to date at 8-20 years after BMS in which 78% of patients had an excellent or good functional outcome score. As a replacement strategy, autologous osteochondral transplantation(AOT) is often indicated for symptomatic large, cystic lesions, including those that have failed previous reparative procedures, such as BMS. Osteochondral autograft transfer carries the inherent advantage over osteochondral allograft of being from the host with fresh viable cartilage, most commonly harvested from the ipsilateral knee. Clinical studies have found favorable results with osteochondral autograft techniques, including a recent systematic review of clinical outcomes at mid-term follow-up demonstrating excellent or good outcomes in 87% of patients. In recent years, Scaffold-based regenerative techniques are getting more attention. Matrix-associated chondrocyte implantation(MACI) is a 2-step procedure in which culture-expanded autologous chondrocytes are seeded on a scaffold, which is then secured in the OLT. More recently, 1-step procedures have been developed in which scaffolds and/or orthobiologics, including bone marrow aspirate concentrate(BMAC) and platelet-rich plasma(PRP), and hyaluronic acid(HA) have been used to augment microfracture with the intention of overcoming the 2-step procedures while concurrently promoting chondrogenic differentiation of endogenous stem cells. Matrix-augmented BMS is one such technique that has been reported with good results in case series. In the future, an advanced strategy for tissue engineering with gene therapy may influence the quality of integration and longevity in treatment of OLT.
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Verghese, Santhosh Chakkaramakkil, Amy M. Skinner, Karen L. Huan, Hans J. Lipps, and Peter Kurre. "Episomal Anchorage Maintains Non-Integrating Lentiviral Vectors in Dividing Cells." Blood 120, no. 21 (November 16, 2012): 4224. http://dx.doi.org/10.1182/blood.v120.21.4224.4224.
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Abstract Abstract 4224 Insertional mutagenesis has been a major setback in retroviral stem cell gene therapy. Vector integration events can induce alternative splicing, aberrant transcripts and read-through transcription of endogenous genes. Non-integrating vectors provide a potentially safer approach in some tissue targets. However, due to the lack of nuclear retention, the vector genome is rapidly lost during cell division and differentiation. Genomic Scaffold/Matrix Associated Regions (S/MARs) efficiently anchor the DNA to nuclear matrix proteins to generate chromosome domains in the nucleus and have been successfully used for non-viral approaches to genetic modification. Here we incorporated human ß-interferon derived S/MAR sequence between GFP reporter reading frame and 3'LTR of a non-integrating 3rd generation lentiviral transfer vector, in an effort to ‘anchor’ the vector (termed ‘aLV’) to the host cell genome in dividing cells. Our approach exploits two key properties of lentiviral life cycle, i.e. nuclear translocation of the viral genomic DNA and circularization to generate episomal genomes comprised of 1-LTR or 2-LTR circles. Integrating vector (iLV) and aLV (integrase-defective gag packaging plasmid) were VSV-G pseudotyped and concentrated, yielding stocks with titers of 2.3 x108 and 3×106 TU/ml, respectively. Transduction of 293T cells with aLV showed dose-dependent transduction and GFP expression similar to iLV. Transduced 293T cells were clonally expanded and maintained in vitro up to 10 weeks. A subset of 22 aLV clones and 9 iLV clones were followed over time and analyzed for transgene expression and molecular persistence of LTR circles. After >70 rounds of cell division, GFP fluorescence intensity was consistently lower, but persisted in aLV-293T clones at MFI 406.5±34.9 versus iLV at MFI 786.3±58.5. As predicted, 1-LTR and 2-LTR vector episomes were detected by PCR in genomic DNA from aLV transduced cells at the 10-week time point. Additional sequencing confirmed the presence of episomal junctions indicating the persistence of completely circularized episomes. With evidence of molecular persistence and GFP expression of S/MAR-anchored, episomal vector genomes in rapidly dividing cell lines, we next tested the performance of aLV in lineage-depleted murine hematopoietic stem and progenitor cells (mHSPCs). Overnight transduction of lin- progenitors at matched MOI yielded 96.3%±22 GFP-positive clonogenic methylcellulose colonies after iLV exposure versus 39.4%±21 after aLV exposure. Transduced mHSPCs were also transplanted into sublethally irradiated C57B/6 mice and peripheral blood leukocytes were analyzed for gene expression. Here GFP expression in the donor compartment averaged 62% for iLV compared with 10% for aLV. We are evaluating leukocyte donor subset GFP expression and will undertake secondary transplantation to formally demonstrate transduction in the stem cell compartment. In summary, lentivector mediated nuclear localization followed by beta-interferon S/MAR anchorage of the vector genome leads to episomal transgene expression in dividing target cells. Our studies suggest that S/MAR elements can serve as molecular anchors for non-integrating lentiviral episomes to provide sustained gene expression through successive rounds of cell division and progenitor differentiation in vitro and in vivo. We propose further study of aLV as a candidate vector for gene delivery to HSPCs while avoiding proviral integration and its potentially deleterious consequences. Disclosures: No relevant conflicts of interest to declare.
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Kolpakov, V. N., Y. I. Pigareva, A. A. Gladkov, A. S. Bukatin, V. B. Kazantsev, I. V. Mukhina, and A. S. Pimashkin. "Model of ‘implant-host’ neural circuits in a microfluidic chip in vitro." Journal of Physics: Conference Series 2086, no. 1 (December 1, 2021): 012111. http://dx.doi.org/10.1088/1742-6596/2086/1/012111.
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Abstract In this study, we developed a new model of neuronal cells plating into a developed neural network to study functional integration using microfluidic methods. The integration was modeled in a three-chamber microfluidic chip by growing two weakly coupled neuronal networks and enhancing its connectivity by plating new dissociated cells. The direction of connections was formed by the asymmetric design of the chip. Such technology can be used to develop a new type of scaffold to recover the modular structure of the network.
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Shokouhimehr, Mohammadreza, Andrea S. Theus, Archana Kamalakar, Liqun Ning, Cong Cao, Martin L. Tomov, Jarred M. Kaiser, et al. "3D Bioprinted Bacteriostatic Hyperelastic Bone Scaffold for Damage-Specific Bone Regeneration." Polymers 13, no. 7 (March 30, 2021): 1099. http://dx.doi.org/10.3390/polym13071099.
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Current strategies for regeneration of large bone fractures yield limited clinical success mainly due to poor integration and healing. Multidisciplinary approaches in design and development of functional tissue engineered scaffolds are required to overcome these translational challenges. Here, a new generation of hyperelastic bone (HB) implants, loaded with superparamagnetic iron oxide nanoparticles (SPIONs), are 3D bioprinted and their regenerative effect on large non-healing bone fractures is studied. Scaffolds are bioprinted with the geometry that closely correspond to that of the bone defect, using an osteoconductive, highly elastic, surgically friendly bioink mainly composed of hydroxyapatite. Incorporation of SPIONs into HB bioink results in enhanced bacteriostatic properties of bone grafts while exhibiting no cytotoxicity. In vitro culture of mouse embryonic cells and human osteoblast-like cells remain viable and functional up to 14 days on printed HB scaffolds. Implantation of damage-specific bioprinted constructs into a rat model of femoral bone defect demonstrates significant regenerative effect over the 2-week time course. While no infection, immune rejection, or fibrotic encapsulation is observed, HB grafts show rapid integration with host tissue, ossification, and growth of new bone. These results suggest a great translational potential for 3D bioprinted HB scaffolds, laden with functional nanoparticles, for hard tissue engineering applications.
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Gonzalez, Brittany A., Ariadna Herrera, Claudia Ponce, Marcos Gonzalez Perez, Chia-Pei Denise Hsu, Asad Mirza, Manuel Perez, and Sharan Ramaswamy. "Stem Cell-Secreted Allogeneic Elastin-Rich Matrix with Subsequent Decellularization for the Treatment of Critical Valve Diseases in the Young." Bioengineering 9, no. 10 (October 20, 2022): 587. http://dx.doi.org/10.3390/bioengineering9100587.
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Critical valve diseases in infants have a very poor prognosis for survival. Particularly challenging is for the valve replacement to support somatic growth. From a valve regenerative standpoint, bio-scaffolds have been extensively investigated recently. While bio-scaffold valves facilitate acute valve functionality, their xenogeneic properties eventually induce a hostile immune response. Our goal was to investigate if a bio-scaffold valve could be deposited with tissues derived from allogeneic stem cells, with a specific dynamic culture protocol to enhance the extracellular matrix (ECM) constituents, with subsequent stem cell removal. Porcine small intestinal submucosa (PSIS) tubular-shaped bio-scaffold valves were seeded with human bone marrow-derived mesenchymal stem cells (hBMMSCs), cultured statically for 8 days, and then exposed to oscillatory fluid-induced shear stresses for two weeks. The valves were then safely decellularized to remove the hBMMSCs while retaining their secreted ECM. This de novo ECM was found to include significantly higher (p < 0.05) levels of elastin compared to the ECM produced by the hBMMSCs under standard rotisserie culture. The elastin-rich valves consisted of ~8% elastin compared to the ~10% elastin composition of native heart valves. Allogeneic elastin promotes chemotaxis thereby accelerating regeneration and can support somatic growth by rapidly integrating with the host following implantation. As a proof-of-concept of accelerated regeneration, we found that valve interstitial cells (VICs) secreted significantly more (p < 0.05) collagen on the elastin-rich matrix compared to the raw PSIS bio-scaffold.
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Patumcharoenpol, Preecha, Massalin Nakphaichit, Gianni Panagiotou, Anchalee Senavonge, Narissara Suratannon, and Wanwipa Vongsangnak. "MetGEMs Toolbox: Metagenome-scale models as integrative toolbox for uncovering metabolic functions and routes of human gut microbiome." PLOS Computational Biology 17, no. 1 (January 6, 2021): e1008487. http://dx.doi.org/10.1371/journal.pcbi.1008487.
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Investigating metabolic functional capability of a human gut microbiome enables the quantification of microbiome changes, which can cause a phenotypic change of host physiology and disease. One possible way to estimate the functional capability of a microbial community is through inferring metagenomic content from 16S rRNA gene sequences. Genome-scale models (GEMs) can be used as scaffold for functional estimation analysis at a systematic level, however up to date, there is no integrative toolbox based on GEMs for uncovering metabolic functions. Here, we developed the MetGEMs (metagenome-scale models) toolbox, an open-source application for inferring metabolic functions from 16S rRNA gene sequences to facilitate the study of the human gut microbiome by the wider scientific community. The developed toolbox was validated using shotgun metagenomic data and shown to be superior in predicting functional composition in human clinical samples compared to existing state-of-the-art tools. Therefore, the MetGEMs toolbox was subsequently applied for annotating putative enzyme functions and metabolic routes related in human disease using atopic dermatitis as a case study.
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Barbon, Silvia, Elena Stocco, Martina Contran, Federico Facchin, Rafael Boscolo-Berto, Silvia Todros, Deborah Sandrin, et al. "Preclinical Development of Bioengineered Allografts Derived from Decellularized Human Diaphragm." Biomedicines 10, no. 4 (March 22, 2022): 739. http://dx.doi.org/10.3390/biomedicines10040739.
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Volumetric muscle loss (VML) is the traumatic/surgical loss of skeletal muscle, causing aesthetic damage and functional impairment. Suboptimal current surgical treatments are driving research towards the development of optimised regenerative therapies. The grafting of bioengineered scaffolds derived from decellularized skeletal muscle may be a valid option to promote structural and functional healing. In this work, a cellular human diaphragm was considered as a scaffold material for VML treatment. Decellularization occurred through four detergent-enzymatic protocols involving (1) sodium dodecyl sulfate (SDS), (2) SDS + TergitolTM, (3) sodium deoxycholate, and (4) TergitolTM. After decellularization, cells, DNA (≤50 ng/mg of tissue), and muscle fibres were efficiently removed, with the preservation of collagen/elastin and 60%–70% of the glycosaminoglycan component. The detergent-enzymatic treatments did not affect the expression of specific extracellular matrix markers (Collagen I and IV, Laminin), while causing the loss of HLA-DR expression to produce non-immunogenic grafts. Adipose-derived stem cells grown by indirect co-culture with decellularized samples maintained 80%–90% viability, demonstrating the biosafety of the scaffolds. Overall, the tested protocols were quite equivalent, with the patches treated by SDS + TergitolTM showing better collagen preservation. After subcutaneous implant in Balb/c mice, these acellular diaphragmatic grafts did not elicit a severe immune reaction, integrating with the host tissue.
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Henckes, Nicole Andréa Corbellini, Laura Chuang, Isadora Bosak, Rafael Carazzai, Tuane Garcez, Cristiana Palma Kuhl, Fernanda dos Santos de Oliveira, Luis Alberto Loureiro dos Santos, Fernanda Visioli, and Elizabeth Obino Cirne-Lima. "Tissue engineering application combining epoxidized natural rubber blend and mesenchymal stem cells in in vivo response." Journal of Biomaterials Applications, June 22, 2022, 088532822211104. http://dx.doi.org/10.1177/08853282221110476.
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This study aimed to investigate biocompatibility, integration, and tissue host response of the Poly (Lactic-co-Glycolic acid) (PLGA)/Poly (isoprene) (PI) epoxidized (PLGA/PIepox) innovative scaffold combined with adipose derived mesenchymal stem cells (ADSC). We implanted the scaffold subcutaneously on the back of 18 female rats and monitored them for up to 14 days. When compared to controls, PLGA/PIepox + ADSC demonstrated an earlier vascularization, a tendency of inflammation reduction, an adequate tissue integration, higher cell proliferation, and a tendency of expression of collagen decreasing. However, 14 days post-implantation we found similar levels of CD31, Ki67 and AE1/AE3 in PLGA/PIepox when compared to control groups. The interesting results, lead us to the assumption that PLGA/PIepox is able to provide an effective delivery system for ADSC on tissue host. This animal study assesses PLGA/PIepox + ADSC in in vivo tissue functionality and validation of use, serving as a proof of concept for future clinical translation as it presents an innovative and promising tissue engineering opportunity for the use in tissue reconstruction.
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Clough, Daniel W., Jessica L. King, Feiran Li, and Lonnie D. Shea. "Integration of Islet/Beta-Cell Transplants with Host Tissue Using Biomaterial Platforms." Endocrinology 161, no. 11 (September 7, 2020). http://dx.doi.org/10.1210/endocr/bqaa156.
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Abstract Cell-based therapies are emerging for type I diabetes mellitus (T1D), an autoimmune disease characterized by the destruction of insulin-producing pancreatic β-cells, as a means to provide long-term restoration of glycemic control. Biomaterial scaffolds provide an opportunity to enhance the manufacturing and transplantation of islets or stem cell–derived β-cells. In contrast to encapsulation strategies that prevent host contact with the graft, recent approaches aim to integrate the transplant with the host to facilitate glucose sensing and insulin distribution, while also needing to modulate the immune response. Scaffolds can provide a supportive niche for cells either during the manufacturing process or following transplantation at extrahepatic sites. Scaffolds are being functionalized to deliver oxygen, angiogenic, anti-inflammatory, or trophic factors, and may facilitate cotransplantation of cells that can enhance engraftment or modulate immune responses. This local engineering of the transplant environment can complement systemic approaches for maximizing β-cell function or modulating immune responses leading to rejection. This review discusses the various scaffold platforms and design parameters that have been identified for the manufacture of human pluripotent stem cell–derived β-cells, and the transplantation of islets/β-cells to maintain normal blood glucose levels.
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Cheng, Baixiang, Teng Tu, Xiao Shi, Yanzheng Liu, Ying Zhao, Yinhua Zhao, Yijie Li, Hui Chen, Yongjin Chen, and Min Zhang. "A novel construct with biomechanical flexibility for articular cartilage regeneration." Stem Cell Research & Therapy 10, no. 1 (September 23, 2019). http://dx.doi.org/10.1186/s13287-019-1399-2.
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Abstract Background Although tissue-engineered cartilage has been broadly studied, complete integration of regenerated cartilage with residual cartilage is still difficult for the inferior mechanical and biochemical feature of neocartilage. Chondrogenesis of mesenchymal stem cells can be induced by biophysical and biochemical factors. Methods In this study, autologous platelet-rich fibrin (PRF) membrane was used as a growth factor-rich scaffold that may facilitate differentiation of the transplanted bone marrow mesenchymal stem cells (BMSCs). At the same time, hydrostatic pressure was adopted for pre-adjustment of the seed cells before transplantation that may promote the mechanical flexibility of neocartilage. Results An in vitro study showed that the feasible hydrostatic pressure stimulation substantially promoted the chondrogenic potential of in vitro-cultured BMSC/PRF construct. In vivo results revealed that at every time point, the newborn tissues were the most favorable in the pressure-pretreated BMSC/PRF transplant group. Besides, the transplantation of feasible hydrostatic pressure-pretreated construct by BMSC sheet fragments and PRF granules could obviously improve the integration between the regenerated cartilage and host cartilage milieu, and thereby achieve boundaryless repair between the neocartilage and residual host cartilage tissue in rabbit temporomandibular joints. It could be concluded that feasible hydrostatic pressure may effectively promote the proliferation and chondrogenic differentiation of BMSCs in a BMSC/PRF construct. Conclusion This newly formed construct with biomechanical flexibility showed a superior capacity for cartilage regeneration by promoting the mechanical properties and integration of neocartilage.
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Chen, Jiaxi, Huiqun Zhou, Daping Xie, and Yiming Niu. "Bletilla striata polysaccharide cryogel scaffold for spatial control of foreign-body reaction." Chinese Medicine 16, no. 1 (December 2021). http://dx.doi.org/10.1186/s13020-021-00526-y.
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Abstract Background Implantation of a biomaterial may induce the foreign-body reaction to the host tissue that determines the outcome of the integration and the biological performance of the implants. The foreign-body reaction can be modulated by control of the material properties of the implants. Methods First, we synthesized methacrylated Bletilla striata Polysaccharide (BSP-MA) and constructed a series of open porous cryogels utilizing this material via the freezing-thawing treatment of solvent-precursors systems. Second, Pore size and modulus were measured to characterize the properties of BSP cryogels. Live/dead staining of cells and CCK-8 were performed to test the cytocompatibility of the scaffolds. In addition, the Real-Time qPCR experiments were carried for the tests. Finally, the BSP scaffolds were implanted subcutaneously to verify the foreign-body reaction between host tissue and materials. Results Our data demonstrated that cryogels with different pore sizes and modulus can be fabricated by just adjusting the concentration. Besides, the cryogels showed well cytocompatibility in the in vitro experiments and exhibited upregulated expression levels of pro-inflammation-related genes (Tnfa and Il1b) with the increase of pore size. In vivo experiments further proved that with the increase of pore size, more immune cells infiltrated into the inner zone of materials. The foreign-body reaction and the distribution of immune-regulatory cells could be modulated by tuning the material microstructure. Conclusions Collectively, our findings revealed Bletilla striata polysaccharide cryogel scaffold with different pore sizes can spatially control foreign-body reaction. The microstructure of cryogels could differentially guide the distribution of inflammatory cells, affect the formation of blood vessels and fibrous capsules, which eventually influence the material-tissue integration. This work demonstrates a practical strategy to regulate foreign body reaction and promote the performance of medical devices.