Journal articles on the topic 'Cell-free scaffolds'
To see the other types of publications on this topic, follow the link: Cell-free scaffolds.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Cell-free scaffolds.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Kwan, Haowen, Emanuele Chisari, and Wasim S. Khan. "Cell-Free Scaffolds as a Monotherapy for Focal Chondral Knee Defects." Materials 13, no. 2 (January 9, 2020): 306. http://dx.doi.org/10.3390/ma13020306.
Full textAbstract:
Chondral knee defects have a limited ability to be repaired. Current surgical interventions have been unable to regenerate articular cartilage with the mechanical properties of native hyaline cartilage. The use of a scaffold-based approach is a potential solution. Scaffolds are often implanted with cells to stimulate cartilage regeneration, but cell-based therapies are associated with additional regulatory restrictions, an additional surgical procedure for cell harvest, time for cell expansion, and the associated costs. To overcome these disadvantages, cell-free scaffolds can be used in isolation allowing native cells to attach over time. This review discusses the optimal properties of scaffolds used for chondral defects, and the evidence for the use of hydrogel scaffolds and hydrogel–synthetic polymer hybrid scaffolds. Preclinical and clinical studies have shown that cell-free scaffolds can support articular cartilage regeneration and have the potential to treat chondral defects. However, there are very few studies in this area and, despite the many biomaterials tested in cell-based scaffolds, most cell-free studies focused on a specific type I collagen scaffold. Future studies on cell-free scaffolds should adopt the modifications made to cell-based scaffolds and replicate them in the clinical setting. More studies are also needed to understand the underlying mechanism of cell-free scaffolds.
2
Valdoz, Jonard Corpuz, Benjamin C. Johnson, Dallin J. Jacobs, Nicholas A. Franks, Ethan L. Dodson, Cecilia Sanders, Collin G. Cribbs, and Pam M. Van Ry. "The ECM: To Scaffold, or Not to Scaffold, That Is the Question." International Journal of Molecular Sciences 22, no. 23 (November 24, 2021): 12690. http://dx.doi.org/10.3390/ijms222312690.
Full textAbstract:
The extracellular matrix (ECM) has pleiotropic effects, ranging from cell adhesion to cell survival. In tissue engineering, the use of ECM and ECM-like scaffolds has separated the field into two distinct areas—scaffold-based and scaffold-free. Scaffold-free techniques are used in creating reproducible cell aggregates which have massive potential for high-throughput, reproducible drug screening and disease modeling. Though, the lack of ECM prevents certain cells from surviving and proliferating. Thus, tissue engineers use scaffolds to mimic the native ECM and produce organotypic models which show more reliability in disease modeling. However, scaffold-based techniques come at a trade-off of reproducibility and throughput. To bridge the tissue engineering dichotomy, we posit that finding novel ways to incorporate the ECM in scaffold-free cultures can synergize these two disparate techniques.
3
Xu, Shanglong, Yue Yang, Xibin Wang, and Chaofeng Wang. "Branched Channel Scaffolds Fabricated by SFF for Direct Cell Growth Observations." Journal of Bioactive and Compatible Polymers 24, no. 1_suppl (May 2009): 63–74. http://dx.doi.org/10.1177/0883911509103602.
Full textAbstract:
A β-TCP scaffold with a branched channel system was designed to create a novel micro-device that allowed culture perfusion and direct time observation of the cells attached. The scaffold was made by indirect solid free form fabrication (SFF) technology. The flow channel structure was exposed so that the perfusion of the mesenchymal stem cell (MSC) culture could be viewed directly. The cell-seeded scaffolds were continuously perfused for 7 days in the micro-device; during this time, it was possible to observe the dynamic culture processes with cells adhering to the scaffolds and real time cell growth directly. This concept has great potential for use in bone tissue engineering and for versatile fabrication of enhanced scaffolds.
4
Barreto, Rodrigo SN, Patricia Romagnolli, Paula Fratini, Andrea Maria Mess, and Maria Angelica Miglino. "Mouse placental scaffolds: a three-dimensional environment model for recellularization." Journal of Tissue Engineering 10 (January 2019): 204173141986796. http://dx.doi.org/10.1177/2041731419867962.
Full textAbstract:
The rich extracellular matrix (ECM) and availability make placenta eligible as alternative biomaterial source. Herein we produced placental mouse scaffolds by decellularization, and structure, composition, and cytocompatibility were evaluated to be considered as a biomaterial. We obtained a cell-free scaffold containing 9.42 ± 5.2 ng dsDNA per mg of ECM, presenting well-preserved structure and composition. Proteoglycans were widespread throughout ECM without cell nuclei and cell remnants. Collagen I, weak in native placenta, clearly appears in the scaffold after recellularization, opposite distribution was observed for collagen III. Fibronectin was well-observed in placental scaffolds whereas laminin and collagen IV were strong expressed. Placental scaffolds recellularization potential was confirmed after mouse embryonic fibroblasts 3D dynamic culture, resulting in massive scaffold repopulation with cell–cell interactions, cell-matrix adhesion, and maintenance of natural morphology. Our small size scaffolds provide a useful tool for tissue engineering to produce grafts and organ fragments, as well as for cellular biology purposes for tridimensional culture substrate.
5
Khandaker, Morshed, Hembafan Nomhwange, Helga Progri, Sadegh Nikfarjam, and Melville B. Vaughan. "Evaluation of Polycaprolactone Electrospun Nanofiber-Composites for Artificial Skin Based on Dermal Fibroblast Culture." Bioengineering 9, no. 1 (January 6, 2022): 19. http://dx.doi.org/10.3390/bioengineering9010019.
Full textAbstract:
The study’s aim was to develop a dermal equivalent scaffold that can mimic the architecture and biological performance of the human dermis. Poly ε-caprolactone (PCL) electrospun nanofiber material (ENF) was assembled with polyethylene glycol diacrylate (PEGDA), sodium alginate (SA) and type I collagen (CG1) to develop three groups of dermal equivalent scaffolds. These scaffolds were named PEGDA-PCL, SA-PCL and CG1-PCL. Scanning electron microscopy (SEM) images of cell-free scaffolds’ top and cross-sectional surface were collected and analyzed to examine internal morphology, specifically the adhesiveness of PCL fibers with the different scaffolds. Human dermal fibroblasts were cultured on each of the scaffolds. Cell viability studies including cell adhesion, cell differentiation and stress fiber production were conducted on each scaffold. Furthermore, the architectural integrity of each scaffold was verified by degradation analysis for 2 weeks by soaking each scaffold in phosphate-buffered saline (PBS) solution. Finally, we conducted rheological characteristics of each scaffold. Based on our results from the above analysis, the study concluded that CG1-PCL is best suitable for the dermal equivalent model and has potential to be used as a graft for skin repair.
6
Soares, D. G., E. A. F. Bordini, E. S. Bronze-Uhle, F. B. Cassiano, I. S. P. Silva, M. O. Gallinari, H. R. Matheus, et al. "Chitosan-Calcium-Simvastatin Scaffold as an Inductive Cell-Free Platform." Journal of Dental Research 100, no. 10 (July 27, 2021): 1118–26. http://dx.doi.org/10.1177/00220345211024207.
Full textAbstract:
The development of biomaterials based on the combination of biopolymers with bioactive compounds to develop delivery systems capable of modulating dentin regeneration mediated by resident cells is the goal of current biology-based strategies for regenerative dentistry. In this article, the bioactive potential of a simvastatin (SV)–releasing chitosan-calcium-hydroxide (CH-Ca) scaffold was assessed. After the incorporation of SV into CH-Ca, characterization of the scaffold was performed. Dental pulp cells (DPCs) were seeded onto scaffolds for the assessment of cytocompatibility, and odontoblastic differentiation was evaluated in a microenvironment surrounded by dentin. Thereafter, the cell-free scaffold was adapted to dentin discs positioned in artificial pulp chambers in direct contact with a 3-dimensional (3D) culture of DPCs, and the system was sealed to simulate internal pressure at 20 cm/H2O. In vivo experiments with cell-free scaffolds were performed in rats’ calvaria defects. Fourier-transform infrared spectroscopy spectra proved incorporation of Ca and SV into the scaffold structure. Ca and SV were released upon immersion in a neutral environment. Viable DPCs were able to spread and proliferate on the scaffold over 14 d. Odontoblastic differentiation occurred in the DPC/scaffold constructs in contact with dentin, in which SV supplementation promoted odontoblastic marker overexpression and enhanced mineralized matrix deposition. The chemoattractant potential of the CH-Ca scaffold was improved by SV, with numerous viable and dentin sialoprotein–positive cells from the 3D culture being observed on its surface. Cells at 3D culture featured increased gene expression of odontoblastic markers in contact with the SV-enriched CH-Ca scaffold. CH-Ca-SV led to intense mineralization in vivo, presenting mineralization foci inside its structure. In conclusion, the CH-Ca-SV scaffold induces differentiation of DPCs into a highly mineralizing phenotype in the presence of dentin, creating a microenvironment capable of attracting pulp cells to its surface and inducing the overexpression of odontoblastic markers in a cell-homing strategy.
7
Lahner, Matthias, Christian Duif, Andreas Ficklscherer, Christian Kaps, Lukas Kalwa, and Tobias Seidl. "Arthroscopic Fixation of Cell Free Polymer-Based Cartilage Implants with a Bioinspired Polymer Surface on the Hip Joint: A Cadaveric Pilot Study." BioMed Research International 2014 (2014): 1–6. http://dx.doi.org/10.1155/2014/717912.
Full textAbstract:
This study investigates the adhesion capacity of a polyglycolic acid- (PGA-) hyaluronan scaffold with a structural modification based on a planar polymer (PM) surface in a cadaver cartilage defect model. Two cadaver specimens were used to serially test multiple chondral matrices. In a cadaver hip model, cell free polymer-based cartilage implants with a planar bioinspired PM surface (PGA-PM-scaffolds) were implanted arthroscopically on 10 mm × 15 mm full-thickness femoral hip cartilage lesions. Unprocessed cartilage implants without a bioinspired PM surface were used as control group. The cartilage implants were fixed without and with the use of fibrin glue on femoral hip cartilage defects. After 50 movement cycles and removal of the distraction, a rearthroscopy was performed to assess the outline attachment and integrity of the scaffold. The fixation techniques without and with fibrin fixation showed marginal differences for outline attachment, area coverage, scaffold integrity, and endpoint fixation after 50 cycles. The PGA-PM-scaffolds with fibrin fixation achieved a higher score in terms of the attachment, integrity, and endpoint fixation than the PGA-scaffold on the cartilage defect. Relating to the outline attachment, area coverage, scaffold integrity, and endpoint fixation, the fixation with PGA-PM-scaffolds accomplished significantly better results compared to the PGA-scaffolds(P=0.03752, P=0.03078, P=0.00512, P=0.00512). PGA-PM-scaffolds demonstrate increased observed initial fixation strength in cadaver femoral head defects relative to PGA-scaffold, particularly when fibrin glue is used for fixation.
8
Mattioli-Belmonte, Monica, Francesca Montemurro, Caterina Licini, Iolanda Iezzi, Manuela Dicarlo, Giorgia Cerqueni, Florinda Coro, and Giovanni Vozzi. "Cell-Free Demineralized Bone Matrix for Mesenchymal Stem Cells Survival and Colonization." Materials 12, no. 9 (April 26, 2019): 1360. http://dx.doi.org/10.3390/ma12091360.
Full textAbstract:
Decellularized bone matrix is receiving much attention as biological scaffolds and implantable biomaterials for bone tissue regeneration. Here, we evaluated the efficacy of a cell-free demineralized bone matrix on mesenchymal stem cells (MSCs) survival and differentiation in vitro. The seeding of human umbilical cord-derived MSCs (hUC-SCs) on decellularized bone matrices up to 14 days was exploited, assessing their capability of scaffold colonization and evaluating gene expression of bone markers. Light and Scanning Electron Microscopies were used. The obtained cell-free decalcified structures showed elastic moduli attributable to both topology and biochemical composition. Morphological observation evidenced an almost complete colonization of the scaffolds after 14 days of culture. Moreover, in hUC-SCs cultured on decalcified scaffolds, without the addition of any osteoinductive media, there was an upregulation of Collagen Type I (COL1) and osteonectin (ON) gene expression, especially on day 14. Modifications in the expression of genes engaged in stemness were also detected. In conclusion, the proposed decellularized bone matrix can induce the in vitro hUC-SCs differentiation and has the potential to be tested for in in vivo tissue regeneration.
9
Huang, Zhao, Benjamin Kohl, Maria Kokozidou, Stephan Arens, and Gundula Schulze-Tanzil. "Establishment of a Cytocompatible Cell-Free Intervertebral Disc Matrix for Chondrogenesis with Human Bone Marrow-Derived Mesenchymal Stromal Cells." Cells Tissues Organs 201, no. 5 (2016): 354–65. http://dx.doi.org/10.1159/000444521.
Full textAbstract:
Tissue-engineered intervertebral discs (IVDs) utilizing decellularized extracellular matrix (ECM) could be an option for the reconstruction of impaired IVDs due to degeneration or injury. The objective of this study was to prepare a cell-free decellularized human IVD scaffold and to compare neotissue formation in response to recellularization with human IVD cells (hIVDCs) or human bone marrow-derived (hBM) mesenchymal stromal cells (MSCs). IVDs were decellularized via freeze-thaw cycles, detergents and trypsin. Histological staining was performed to monitor cell removal and glycosaminoglycan (GAG) removal. The decellularized IVD was preconditioned using bovine serum albumin and fetal bovine serum before its cytocompatibility for dynamically cultured hBM-MSCs (chondrogenically induced or not) and hIVDCs was compared after 14 days. In addition, DNA, total collagen and GAG contents were assessed. The decellularization protocol achieved maximal cell removal, with only few remaining cell nuclei compared with native tissue, and low toxicity. The DNA content was significantly higher in scaffolds seeded with hIVDCs compared with native IVDs, cell-free and hBM-MSC-seeded scaffolds (p < 0.01). The GAG content in the native tissue was significantly higher compared to the others groups except for the scaffolds reseeded with chondrogenically induced hBM-MSCs (p < 0.05). In addition, there was a significantly increased total collagen content in the chondrogenically induced hBM-MSCs group (p < 0.01) compared with the native IVDs, cell-free and hIVDC-seeded scaffolds (p < 0.01); both recolonizing cell types were more evenly distributed on the scaffold surface, but only few cells penetrated the scaffold. The resulting decellularized ECM was cytocompatible and allowed hBM-MSCs/hIVDCs survival and ECM production.
10
Salerno, Aurelio, Giuseppe Cesarelli, Parisa Pedram, and Paolo Antonio Netti. "Modular Strategies to Build Cell-Free and Cell-Laden Scaffolds towards Bioengineered Tissues and Organs." Journal of Clinical Medicine 8, no. 11 (November 1, 2019): 1816. http://dx.doi.org/10.3390/jcm8111816.
Full textAbstract:
Engineering three-dimensional (3D) scaffolds for functional tissue and organ regeneration is a major challenge of the tissue engineering (TE) community. Great progress has been made in developing scaffolds to support cells in 3D, and to date, several implantable scaffolds are available for treating damaged and dysfunctional tissues, such as bone, osteochondral, cardiac and nerve. However, recapitulating the complex extracellular matrix (ECM) functions of native tissues is far from being achieved in synthetic scaffolds. Modular TE is an intriguing approach that aims to design and fabricate ECM-mimicking scaffolds by the bottom-up assembly of building blocks with specific composition, morphology and structural properties. This review provides an overview of the main strategies to build synthetic TE scaffolds through bioactive modules assembly and classifies them into two distinct schemes based on microparticles (µPs) or patterned layers. The µPs-based processes section starts describing novel techniques for creating polymeric µPs with desired composition, morphology, size and shape. Later, the discussion focuses on µPs-based scaffolds design principles and processes. In particular, starting from random µPs assembly, we will move to advanced µPs structuring processes, focusing our attention on technological and engineering aspects related to cell-free and cell-laden strategies. The second part of this review article illustrates layer-by-layer modular scaffolds fabrication based on discontinuous, where layers’ fabrication and assembly are split, and continuous processes.
11
Irem Demir, Ahder, Anil Pulatkan, Vahdet Ucan, Bengi Yilmaz, Aydin Tahmasebifar, Olgu Enis Tok, Ibrahim Tuncay, Nurzat Elmali, Burak Yagmur Ozturk, and Gokcer Uzer. "Comparison of 3 Cell-Free Matrix Scaffolds Used to Treat Osteochondral Lesions in a Rabbit Model." American Journal of Sports Medicine 50, no. 5 (March 30, 2022): 1399–408. http://dx.doi.org/10.1177/03635465221074292.
Full textAbstract:
Background: Various cell-free scaffolds are already in use for the treatment of osteochondral defects (OCDs); however, a gold standard material has not yet been defined. Purpose: This study compared the macroscopic, histological, and scanning electron microscopy (SEM) characteristics of Chondro-Gide (CG), MaioRegen (MA), and poly-d,l-lactide-co-caprolactone (PLCL) cell-free scaffolds enhanced with small-diameter microfractures (SDMs) for OCDs in a rabbit model. Study Design: Controlled laboratory study. Methods: In total, 54 knees from 27 rabbits were used in this study. Three rabbits were sacrificed at the beginning of the study to form an intact cartilage control group (group IC). An OCD model was created at the center of the trochlea, and SDMs were generated in 24 rabbits. Rabbits with OCDs were divided into 4 groups (n = 12 knees per group) according to the cell-free scaffold applied: CG (group CG), MA (group MA), PLCL (group PLCL), and a control group (group SDM). Half of the rabbits were sacrificed at 1 month after treatment, while the other half were sacrificed at 3 months after treatment. Healed cartilage was evaluated macroscopically (using International Cartilage Regeneration & Joint Preservation Society [ICRS] classification criteria) and histopathologically (using modified O’Driscoll scores and collagen staining). Additionally, cell-free scaffold morphologies were compared using SEM analysis. Results: ICRS and modified O’Driscoll classification and staining with collagen type 1 and type 2 demonstrated significant differences among groups at both 1 and 3 months after treatment ( P < .05). The histological characteristics of the group IC samples were superior to those of all other groups, except group PLCL, at 3 months after treatment ( P < .05). In addition, the histological properties of group PLCL samples were superior to those of group SDM samples at both 1 and 3 months after treatment in terms of the modified O’Driscoll scores and type 1 collagen staining ( P < .05). Concerning type 2 collagen staining intensity, the groups were ranked from highest to lowest at 3 months after treatment as follows: group PLCL (30.3 ± 2.6) > group MA (26.6 ± 1.2) > group CG (23.3 ± 2.3) > group SDM (18.9 ± 0.9). Conclusion: OCDs treated with enhanced SDM using cell-free PLCL scaffolds had superior histopathological and microenvironmental properties, more hyaline cartilage, and more type 2 collagen compared with those treated using CG or MA scaffolds. Clinical Relevance: OCDs treated with PLCL cell-free scaffolds may have superior histopathological properties and contain more type 2 collagen than do OCDs treated with CG or MA cell-free scaffolds.
12
Zhang, Zheng-Zheng, Shao-Jie Wang, Ji-Ying Zhang, Wen-Bo Jiang, Ai-Bing Huang, Yan-Song Qi, Jian-Xun Ding, Xue-Si Chen, Dong Jiang, and Jia-Kuo Yu. "3D-Printed Poly(ε-caprolactone) Scaffold Augmented With Mesenchymal Stem Cells for Total Meniscal Substitution: A 12- and 24-Week Animal Study in a Rabbit Model." American Journal of Sports Medicine 45, no. 7 (March 9, 2017): 1497–511. http://dx.doi.org/10.1177/0363546517691513.
Full textAbstract:
Background: Total meniscectomy leads to knee osteoarthritis in the long term. The poly(ε-caprolactone) (PCL) scaffold is a promising material for meniscal tissue regeneration, but cell-free scaffolds result in relatively poor tissue regeneration and lead to joint degeneration. Hypothesis: A novel, 3-dimensional (3D)–printed PCL scaffold augmented with mesenchymal stem cells (MSCs) would offer benefits in meniscal regeneration and cartilage protection. Study Design: Controlled laboratory study. Methods: PCL meniscal scaffolds were 3D printed and seeded with bone marrow–derived MSCs. Seventy-two New Zealand White rabbits were included and were divided into 4 groups: cell-seeded scaffold, cell-free scaffold, sham operation, and total meniscectomy alone. The regeneration of the implanted tissue and the degeneration of articular cartilage were assessed by gross and microscopic (histological and scanning electron microscope) analysis at 12 and 24 weeks postoperatively. The mechanical properties of implants were also evaluated (tensile and compressive testing). Results: Compared with the cell-free group, the cell-seeded scaffold showed notably better gross appearance, with a shiny white color and a smooth surface. Fibrochondrocytes with extracellular collagen type I, II, and III and proteoglycans were found in both seeded and cell-free scaffold implants at 12 and 24 weeks, while the results were significantly better for the cell-seeded group at week 24. Furthermore, the cell-seeded group presented notably lower cartilage degeneration in both femur and tibia compared with the cell-free or meniscectomy group. Both the tensile and compressive properties of the implants in the cell-seeded group were significantly increased compared with those of the cell-free group. Conclusion: Seeding MSCs in the PCL scaffold increased its fibrocartilaginous tissue regeneration and mechanical strength, providing a functional replacement to protect articular cartilage from damage after total meniscectomy. Clinical Relevance: The study suggests the potential of the novel 3D PCL scaffold augmented with MSCs as an alternative meniscal substitution, although this approach requires further improvement before being used in clinical practice.
13
Fernández-Pérez, Julia, Peter W. Madden, Robert Thomas Brady, Peter F. Nowlan, and Mark Ahearne. "The effect of prior long-term recellularization with keratocytes of decellularized porcine corneas implanted in a rabbit anterior lamellar keratoplasty model." PLOS ONE 16, no. 6 (June 1, 2021): e0245406. http://dx.doi.org/10.1371/journal.pone.0245406.
Full textAbstract:
Decellularized porcine corneal scaffolds are a potential alternative to human cornea for keratoplasty. Although clinical trials have reported promising results, there can be corneal haze or scar tissue. Here, we examined if recellularizing the scaffolds with human keratocytes would result in a better outcome. Scaffolds were prepared that retained little DNA (14.89 ± 5.56 ng/mg) and demonstrated a lack of cytotoxicity by in vitro. The scaffolds were recellularized using human corneal stromal cells and cultured for between 14 in serum-supplemented media followed by a further 14 days in either serum free or serum-supplemented media. All groups showed full-depth cell penetration after 14 days. When serum was present, staining for ALDH3A1 remained weak but after serum-free culture, staining was brighter and the keratocytes adopted a native dendritic morphology with an increase (p < 0.05) of keratocan, decorin, lumican and CD34 gene expression. A rabbit anterior lamellar keratoplasty model was used to compare implanting a 250 μm thick decellularized lenticule against one that had been recellularized with human stromal cells after serum-free culture. In both groups, host rabbit epithelium covered the implants, but transparency was not restored after 3 months. Post-mortem histology showed under the epithelium, a less-compact collagen layer, which appeared to be a regenerating zone with some α-SMA staining, indicating fibrotic cells. In the posterior scaffold, ALDH1A1 staining was present in all the acellular scaffold, but in only one of the recellularized lenticules. Since there was little difference between acellular and cell-seeded scaffolds in our in vivo study, future scaffold development should use acellular controls to determine if cells are necessary.
14
Xu, Qi, Michael G. Resch, Kara Podkaminer, Shihui Yang, John O. Baker, Bryon S. Donohoe, Charlotte Wilson, et al. "Dramatic performance ofClostridium thermocellumexplained by its wide range of cellulase modalities." Science Advances 2, no. 2 (February 2016): e1501254. http://dx.doi.org/10.1126/sciadv.1501254.
Full textAbstract:
Clostridium thermocellumis the most efficient microorganism for solubilizing lignocellulosic biomass known to date. Its high cellulose digestion capability is attributed to efficient cellulases consisting of both a free-enzyme system and a tethered cellulosomal system wherein carbohydrate active enzymes (CAZymes) are organized by primary and secondary scaffoldin proteins to generate large protein complexes attached to the bacterial cell wall. This study demonstrates thatC. thermocellumalso uses a type of cellulosomal system not bound to the bacterial cell wall, called the “cell-free” cellulosomal system. The cell-free cellulosome complex can be seen as a “long range cellulosome” because it can diffuse away from the cell and degrade polysaccharide substrates remotely from the bacterial cell. The contribution of these two types of cellulosomal systems inC. thermocellumwas elucidated by characterization of mutants with different combinations of scaffoldin gene deletions. The primary scaffoldin, CipA, was found to play the most important role in cellulose degradation byC. thermocellum, whereas the secondary scaffoldins have less important roles. Additionally, the distinct and efficient mode of action of theC. thermocellumexoproteome, wherein the cellulosomes splay or divide biomass particles, changes when either the primary or secondary scaffolds are removed, showing that the intact wild-type cellulosomal system is necessary for this essential mode of action. This new transcriptional and proteomic evidence shows that a functional primary scaffoldin plays a more important role compared to secondary scaffoldins in the proper regulation of CAZyme genes, cellodextrin transport, and other cellular functions.
15
Tan, K. H., C. K. Chua, K. F. Leong, M. W. Naing, and C. M. Cheah. "Fabrication and characterization of three-dimensional poly(ether-ether-ketone)/-hydroxyapatite biocomposite scaffolds using laser sintering." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 219, no. 3 (March 1, 2005): 183–94. http://dx.doi.org/10.1243/095441105x9345.
Full textAbstract:
The ability to have precise control over porosity, scaffold shape, and internal pore architecture is critical in tissue engineering. For anchorage-dependent cells, the presence of three-dimensional scaffolds with interconnected pore networks is crucial to aid in the proliferation and reorganization of cells. This research explored the potential of rapid prototyping techniques such as selective laser sintering to fabricate solvent-free porous composite polymeric scaffolds comprising of different blends of poly(ether-ether-ketone) (PEEK) and hydroxyapatite (HA). The architecture of the scaffolds was created with a scaffold library of cellular units and a corresponding algorithm to generate the structure. Test specimens were produced and characterized by varying the weight percentage, starting with 10 wt% HA to 40 wt% HA, of physically mixed PEEK-HA powder blends. Characterization analyses including porosity, microstructure, composition of the scaffolds, bioactivity, and in vitro cell viability of the scaffolds were conducted. The results obtained showed a promising approach in fabricating scaffolds which can produce controlled microarchitecture and higher consistency.
16
Chen, Rung-Shu, Sheng-Hao Hsu, Hao-Hueng Chang, and Min-Huey Chen. "Challenge Tooth Regeneration in Adult Dogs with Dental Pulp Stem Cells on 3D-Printed Hydroxyapatite/Polylactic Acid Scaffolds." Cells 10, no. 12 (November 23, 2021): 3277. http://dx.doi.org/10.3390/cells10123277.
Full textAbstract:
Tooth regeneration is an important issue. The purpose of this study was to explore the feasibility of using adult dental pulp stem cells on polylactic acid scaffolds for tooth regeneration. Three teeth were extracted from each side of the lower jaws of two adult dogs. In the experimental group, dental pulp stem cells were isolated and seeded in the 3D-printed hydroxyapatite/polylactic acid (HA/PLA) scaffolds for transplantation into left lower jaw of each dog. The right-side jaw of each dog was transplanted with cell-free scaffolds as the control group. Polychrome sequentially labeling was performed for observation of mineralization. Dental cone beam computed tomography (CBCT) irradiation was used for assessment. Nine months after surgery, dogs were euthanized, and the lower jaws of dogs were sectioned and fixed for histological observation with hematoxylin and eosin staining. The results showed that the degree of mineralization in the experimental group with cells seeded in the scaffolds was significantly higher than that of the control group transplanted with cell-free scaffolds. However, the HA/PLA scaffolds were not completely absorbed in both groups. It is concluded that dental pulp stem cells are important for the mineralization of tooth regeneration. A more rapid absorbable material was required for scaffold design for tooth regeneration.
17
Ibragimova, Shabnam I., Ekaterina V. Medvedeva, Irina A. Romanova, Leonid P. Istranov, Elena V. Istranova, Aleksey V. Lychagin, Andrey A. Nedorubov, Peter S. Timashev, Vladimir I. Telpukhov, and Andrei S. Chagin. "Implantation of Various Cell-Free Matrixes Does Not Contribute to the Restoration of Hyaline Cartilage within Full-Thickness Focal Defects." International Journal of Molecular Sciences 23, no. 1 (December 28, 2021): 292. http://dx.doi.org/10.3390/ijms23010292.
Full textAbstract:
Articular cartilage is a highly organized tissue that has a limited ability to heal. Tissue engineering is actively exploited for joint tissue reconstruction in numerous cases of articular cartilage degeneration associated with trauma, arthrosis, rheumatoid arthritis, and osteoarthritis. However, the optimal scaffolds for cartilage repair are not yet identified. Here we have directly compared five various scaffolds, namely collagen-I membrane, collagen-II membrane, decellularized cartilage, a cellulose-based implant, and commercially available Chondro-Gide® (Geistlich Pharma AG, Wolhusen, Switzerland) collagen membrane. The scaffolds were implanted in osteochondral full-thickness defects, formed on adult Wistar rats using a hand-held cutter with a diameter of 2.0 mm and a depth of up to the subchondral bone. The congruence of the articular surface was almost fully restored by decellularized cartilage and collagen type II-based scaffold. The most vivid restoration was observed 4 months after the implantation. The formation of hyaline cartilage was not detected in any of the groups. Despite cellular infiltration into scaffolds being observed in each group except cellulose, neither chondrocytes nor chondro-progenitors were detected. We concluded that for restoration of hyaline cartilage, scaffolds have to be combined either with cellular therapy or morphogens promoting chondrogenic differentiation.
18
Rabionet, Marc, Emma Polonio, Antonio Guerra, Jessica Martin, Teresa Puig, and Joaquim Ciurana. "Design of a Scaffold Parameter Selection System with Additive Manufacturing for a Biomedical Cell Culture." Materials 11, no. 8 (August 14, 2018): 1427. http://dx.doi.org/10.3390/ma11081427.
Full textAbstract:
Open-source 3D printers mean objects can be quickly and efficiently produced. However, design and fabrication parameters need to be optimized to set up the correct printing procedure; a procedure in which the characteristics of the printing materials selected for use can also influence the process. This work focuses on optimizing the printing process of the open-source 3D extruder machine RepRap, which is used to manufacture poly(ε-caprolactone) (PCL) scaffolds for cell culture applications. PCL is a biocompatible polymer that is free of toxic dye and has been used to fabricate scaffolds, i.e., solid structures suitable for 3D cancer cell cultures. Scaffold cell culture has been described as enhancing cancer stem cell (CSC) populations related to tumor chemoresistance and/or their recurrence after chemotherapy. A RepRap BCN3D+ printer and 3 mm PCL wire were used to fabricate circular scaffolds. Design and fabrication parameters were first determined with SolidWorks and Slic3r software and subsequently optimized following a novel sequential flowchart. In the flowchart described here, the parameters were gradually optimized step by step, by taking several measurable variables of the resulting scaffolds into consideration to guarantee high-quality printing. Three deposition angles (45°, 60° and 90°) were fabricated and tested. MCF-7 breast carcinoma cells and NIH/3T3 murine fibroblasts were used to assess scaffold adequacy for 3D cell cultures. The 60° scaffolds were found to be suitable for the purpose. Therefore, PCL scaffolds fabricated via the flowchart optimization with a RepRap 3D printer could be used for 3D cell cultures and may boost CSCs to study new therapeutic treatments for this malignant population. Moreover, the flowchart defined here could represent a standard procedure for non-engineers (i.e., mainly physicians) when manufacturing new culture systems is required.
19
Martín, Anthony R., Jay M. Patel, Hannah M. Zlotnick, Mackenzie L. Sennet, James L. Carey, and Robert L. Mauck. "2061 Acellular hyaluronic acid scaffold with growth factor delivery for cartilage repair in a large animal model." Journal of Clinical and Translational Science 2, S1 (June 2018): 3. http://dx.doi.org/10.1017/cts.2018.43.
Full textAbstract:
OBJECTIVES/SPECIFIC AIMS: Focal cartilage injuries of the knee joint are common and present a treatment challenge due to minimal intrinsic repair. Cartilage tissue engineering techniques currently used in clinical practice are expensive, cumbersome, and often ineffective in patients with mechanical or medical comorbidities. To address these issues, we developed an acellular nanofibrous scaffold with encapsulated growth factors designed to enhanced articular cartilage repair. Our goal is to evaluate this technology in vitro and pilot a large animal model for eventual translation into human subjects. METHODS/STUDY POPULATION: Hyaluronic acid (HA, 65 kDa) will be methacrylated (~40% modification, MeHA) and conjugated with cell-adhesive (RGD) groups. A solution of 4% wt/vol MeHA, 2% wt/vol polyethylene oxide (900 kDa), 0.05% wt/vol Irgacure 2959, and 0.005% wt/vol stromal cell-derived factor-1α (SDF-1α) and/or transforming growth factor-β3 (TGF-β3) will be prepared in ddH2O. The solution will be electrospun onto a rotating mandrel to achieve a dry scaffold thickness of 0.5 mm. The scaffold matt will be UV cross-linked and 5 mm-diameter samples will be cut out. Four groups of scaffolds will be prepared: MeHA, MeHA+SDF, MeHA+TGF, MeHA+SDF+TGF. All groups will be evaluated for fiber diameter, swell thickness, equilibrium compressive modulus, degradation rate, and growth factor release rate over 4 weeks (n=10). Scaffolds will also be seeded with juvenile porcine MSCs (5×104) in 200 μL of medium incubated for 24 hours. Seeded scaffolds will be evaluated for equilibrium compressive modulus, cell infiltration, and chondrogenesis at 4 and 8 weeks (n=10). Scaffolds will then be evaluated in a juvenile Yucatan minipig cartilage defect model. In total, 6 animals will undergo bilateral knee surgery to create four 4 mm-diameter full-thickness cartilage defects in each trochlear grove. All defects will receive microfracture to release marrow elements. Each knee will receive 2 scaffolds of the same group (replicates) with paired microfracture controls, resulting in a sample size of 3. Animals will be sacrificed at 12 weeks and defects will be evaluated via non-destructive indentation testing for mechanical properties, microCT for defect fill and subchondral bone morphology, and histology for ICRS II Visual Histological Assessment Scoring. RESULTS/ANTICIPATED RESULTS: Our preliminary studies have shown reliable replication of electrospun MeHA scaffolds. We anticipate cross-linking density to correlate positively with compressive modulus, and negatively with swell thickness, degradation rate, and growth factor release rate. We anticipate the addition of SDF-1α and TGF-β3 to increase cell infiltration and chondrogenesis, respectively, within seeded scaffolds. Similarly, we expect minipig defects treated with growth factor-releasing scaffolds to show greater mechanical properties, defect fill, and ICRS II score compared with MeHA scaffolds without growth factor. DISCUSSION/SIGNIFICANCE OF IMPACT: This study has the potential to show how an HA-based cell-free scaffold can be augmented with 2 growth factors that act synergistically to improve cartilage repair in a large animal model. This technology would improve upon the cell-free scaffolds already used clinically for autologous matrix-induced chondrogenesis and is directly translatable.
20
Islam, Mohammad Mirazul, Dina B. AbuSamra, Alexandru Chivu, Pablo Argüeso, Claes H. Dohlman, Hirak K. Patra, James Chodosh, and Miguel González-Andrades. "Optimization of Collagen Chemical Crosslinking to Restore Biocompatibility of Tissue-Engineered Scaffolds." Pharmaceutics 13, no. 6 (June 3, 2021): 832. http://dx.doi.org/10.3390/pharmaceutics13060832.
Full textAbstract:
Collagen scaffolds, one of the most used biomaterials in corneal tissue engineering, are frequently crosslinked to improve mechanical properties, enzyme tolerance, and thermal stability. Crosslinkers such as 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) are compatible with tissues but provide low crosslinking density and reduced mechanical properties. Conversely, crosslinkers such as glutaraldehyde (GTA) can generate mechanically more robust scaffolds; however, they can also induce greater toxicity. Herein, we evaluated the effectivity of double-crosslinking with both EDC and GTA together with the capability of sodium metabisulfite (SM) and sodium borohydride (SB) to neutralize the toxicity and restore biocompatibility after crosslinking. The EDC-crosslinked collagen scaffolds were treated with different concentrations of GTA. To neutralize the free unreacted aldehyde groups, scaffolds were treated with SM or SB. The chemistry involved in these reactions together with the mechanical and functional properties of the collagen scaffolds was evaluated. The viability of the cells grown on the scaffolds was studied using different corneal cell types. The effect of each type of scaffold treatment on human monocyte differentiation was evaluated. One-way ANOVA was used for statistical analysis. The addition of GTA as a double-crosslinking agent significantly improved the mechanical properties and enzymatic stability of the EDC crosslinked collagen scaffold. GTA decreased cell biocompatibility but this effect was reversed by treatment with SB or SM. These agents did not affect the mechanical properties, enzymatic stability, or transparency of the double-crosslinked scaffold. Contact of monocytes with the different scaffolds did not trigger their differentiation into activated macrophages. Our results demonstrate that GTA improves the mechanical properties of EDC crosslinked scaffolds in a dose-dependent manner, and that subsequent treatment with SB or SM partially restores biocompatibility. This novel manufacturing approach would facilitate the translation of collagen-based artificial corneas to the clinical setting.
21
Simsek, Abdulmuttalip, Anthony J. Bullock, Sabi Roman, Chirstoper R. Chapple, and Sheila MacNeil. "Developing improved tissue-engineered buccal mucosa grafts for urethral reconstruction." Canadian Urological Association Journal 12, no. 5 (February 2, 2018): E234–42. http://dx.doi.org/10.5489/cuaj.4826.
Full textAbstract:
Introduction: We aimed to compare alternative synthetic scaffolds suitable for future implantation and to examine the use of an inhibitor of lysyl oxidase (beta-amino-propionitrile [β-APN]) to reduce contraction in these implants.Methods: Three synthetic scaffolds were compared to natural dermis as substrates for the production of tissue-engineered skin. For natural dermis, Euroskin was used to provide a cell-free cadaveric dermis. Synthetic scaffolds consisted of microfibrous poly-L-lactic acid (PLA), nanofibrous poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), and a micro-/nanofibrous trilayer of PLA-PHBV-PLA. The latter were all electrospun and then all four scaffolds (three synthetic, one natural) were placed in six well plates. A culture well was formed on the scaffold using a 1 cm diameter stainless steel ring and 1.5x105 oral fibroblasts were seeded one side; after two days of culture, the ring was placed on the other side of the scaffolds and 3x105 oral keratinocytes were seeded on to the scaffolds and cultured with keratinocytes uppermost. After a further two days of culture, scaffolds were cut to 1 cm2 and raised to an air-liquid interface on stainless steel grids; some were treated with 200 μg/ mL β-APN throughout the culture period (28 days). Contraction in vitro was assessed by serial digital photography of cell-seeded scaffolds and cell-free scaffolds three times a week for 28 days. All cell-seeded scaffolds were assessed for cell metabolic activity, mechanical properties, histology, and morphology by scanning electron microscopy (SEM).Results: The mean fibre diameters and pore sizes of PLA and PHBV scaffolds were 2.4±0.77, 0.85±0.21 μm (p<0.001), and 10.8±2.3, 4.3±1.1 μm (p<0.001), respectively. Oral fibroblasts and keratinocytes were tightly adhered and grew well on both surfaces of trilayer. The ultimate tensile strength (UTS) and Young’s modulus (YM) of PLA samples were significantly lower than Euroskin (p<0.001 and p<0.05, respectively); only the UTS of the trilayer samples was slightly significantly lower (p<0.05). Metabolic activity was significantly increased for cells on all scaffolds, without significant differences between them from Day 0 to Day 28. There were no adverse effects of β-APN on cell viability. With respect to contraction, cells on trilayer and PHBV monolayers did not undergo any significant contraction; however, cells on PLA monolayer and Euroskin contracted 25.3% and 56.4%, respectively, over 28 days. The addition of 200 μg/ml β-APN significantly reduced contraction of Euroskin compared with the control (p<0.01); however, β-APN did not affect PLA contraction during this culture period (p>0.05).Conclusions: This study shows that a trilayer micro-nano-3D porous synthetic scaffold is suitable for oral keratinocyte and fibroblast growth with good cell viability and minimal contraction. This material also has good mechanical properties and histological analyses showed its ability to mimic normal human oral mucosal morphology. Furthermore, synthetic trilayer scaffolds have advantages over biological scaffolds — there is no risk of disease transmission or immunological rejection and they appear resistant to contraction. We suggest they present a good alternative to allodermis for future use in urethral reconstruction.
22
Womack, S. A., D. J. Milner, D. W. Weisgerber, B. A. C. Harley, and M. B. Wheeler. "192 BEHAVIOR OF PORCINE MESENCHYMAL STEM CELLS ON A COLLAGEN-GLYCOSAMINOGLYCAN HYDROGEL SCAFFOLD FOR BONE AND CARTILAGE TISSUE ENGINEERING." Reproduction, Fertility and Development 29, no. 1 (2017): 205. http://dx.doi.org/10.1071/rdv29n1ab192.
Full textAbstract:
The pig is an ideal species for use in tissue engineering studies of bone and cartilage defect repair. Novel collagen-glycosaminoglycan hydrogel (CG) scaffolds have shown promise for supporting bone and cartilage growth from mesenchymal stem cells. In order to determine the suitability of these scaffolds for use in porcine models for bone and cartilage tissue engineering, we have begun to investigate the behaviour of porcine mesenchymal stem cells on this material. The purpose of this study was to determine if mesenchymal stem cells from fat (ASC) or bone marrow (BMSC) displayed better adherence and penetration into the CG scaffold material. The BMSC and ASC isolated from young adult Yorkshire pigs were cultured in DMEM with 10% fetal bovine serum. The ASC and BMSC were then trypsinized and used to seed ~3 mm diameter CG scaffolds with 140,000 cells/scaffold. Scaffolds were then cultured for 10 days by 3 different methods: roller culture, free-floating non-adherent dishes (floating), or attached to tissue culture-treated dishes (static). At the conclusion of the incubation period, the scaffold pieces were then fixed with 4% paraformaldehyde, embedded for cryosectioning, and sliced into 10 µm cryosections. Sections were stained for vimentin and 4’,6-diamidino-2-phenylindole (DAPI) to label cells. Stained sections were observed on a Leica DMB4200 microscope (Leica Microsystems, Wetzlar, Germany) and images acquired using ImagePro Plus software (Media Cybernetics Inc., Rockville, MD, USA). The DAPI-stained cells were counted to determine cell density and expressed as average number of nuclei per millimeter squared for each cell and culture type. Data were analysed by ANOVA utilising a post hoc Holm multiple comparison analysis. Samples from roller cultures did not display adhered cells for either BMSC or ASC. In contrast, floating and static culture allowed both ASC and BMSC to adhere to the scaffold and migrate to the centre of the scaffold equally well. However, significant differences in cell densities were noted between ASC and BMSC on CG scaffolds, with BMSC growing to higher densities than ASC in both floating and static culture. For floating cultures, BMSC-loaded scaffolds exhibited a cell density of 105.7 compared with 53.3 cells/mm2 for ASC (n = 4; P < 0.05). For static cultures, BMSC-loaded scaffolds exhibited a cell density of 128.3 compared with 36.8 cells/mm2 for ASC-loaded samples (n = 3; P < 0.01). Thus, BMSC grow to greater densities more rapidly than ASC and may be more efficient for use in forming bone and cartilage on these scaffolds. Current experiments underway will compare osteogenic and chondrogenic differentiation potential of ASC and BMSC on CG scaffolds, and will attempt to engineer osteochondral interface tissue on CG scaffolds from co-cultures of chondrocytes and stem cells.
23
Muller, Daniel, Harvey Chim, Augustinus Bader, Matthew Whiteman, and Jan-Thorsten Schantz. "Vascular Guidance: Microstructural Scaffold Patterning for Inductive Neovascularization." Stem Cells International 2011 (2011): 1–6. http://dx.doi.org/10.4061/2011/547247.
Full textAbstract:
Current tissue engineering techniques are limited by inadequate vascularisation and perfusion of cell-scaffold constructs. Microstructural patterning through biomimetic vascular channels within a polymer scaffold might induce neovascularization, allowing fabrication of large engineered constructs. The network of vascular channels within a frontal-parietal defect in a patient, originating from the anterior branch of the middle meningeal artery, was modeled using computer-aided design (CAD) techniques and subsequently incorporated into polycaprolactone (PCL) scaffolds fabricated using fused deposition modeling (FDM). Bone marrow-derived mesenchymal stem cells (MSCs) were seeded onto the scaffolds and implanted into a rat model, with an arteriovenous bundle inserted at the proximal extent of the vascular network. After 3 weeks, scaffolds were elevated as a prefabricated composite tissue-polymer flap and transferred using microsurgical technique. Histological examination of explanted scaffolds revealed vascular ingrowth along patterned channels, with abundant capillary and connective tissue formation throughout experimental scaffolds, while control scaffolds showed only granulation tissue. All prefabricated constructs transferred as free flaps survived and were viable. We term this concept “vascular guidance,” whereby neovascularization is guided through customized channels in a scaffold. Our technique might potentially allow fabrication of much larger tissue-engineered constructs than current technologies allow, as well as allowing tailored construct fabrication with a patient-specific vessel network based on CT scan data and CAD technology.
24
Wu, Jingwen, Guohou Miao, Zhichao Zheng, Zhengmao Li, Wen Ren, Caijuan Wu, Yuanjing Li, Zhu Huang, Lan Yang, and Lvhua Guo. "3D printing mesoporous bioactive glass/sodium alginate/gelatin sustained release scaffolds for bone repair." Journal of Biomaterials Applications 33, no. 6 (November 14, 2018): 755–65. http://dx.doi.org/10.1177/0885328218810269.
Full textAbstract:
Drug delivery and release are a major challenge fabricating bone tissue engineering. In this study, we fabricated new sustained release hydrogel scaffolds composited of mesoporous bioactive glass, sodium alginate and gelatin by a three-dimensional printing technique. Naringin and calcitonin gene-related peptide were used as drugs to prepare drug-loaded scaffolds by direct printing or surface absorption. The physicochemical properties of the scaffolds and the drug release profiles of the two drug-loading models were investigated. We also examined the biocompatibility of the scaffolds, as well as the effect of the released medium on the proliferation and osteogenic differentiation of human osteoblast-like MG-63 cell. The results showed that the scaffolds had a high porosity (approximately 80%) with an interconnected cubic pore structure, rough surface morphology, bioactivity and strong biocompatibility. Furthermore, the naringin or calcitonin gene-related peptide co-printed into the scaffold displayed a steady sustained release behaviour for up to 21 days without an initial burst release, while both naringin and calcitonin gene-related peptide absorbed onto the surface of the scaffold were completely released within two days. MG-63 cells cultured with the extraction containing released drugs displayed promoted cell proliferation and the expression of osteogenesis-related genes more effectively compared with the drug-free extractions. Therefore, these results demonstrate that the developed mesoporous bioactive glass/sodium alginate/gelatin sustained release scaffolds provide a potential application for bone tissue engineering.
25
Stocco, Elena, Silvia Barbon, Alessia Lamanna, Enrico De Rose, Annj Zamuner, Deborah Sandrin, Martina Marsotto, et al. "Bioactivated Oxidized Polyvinyl Alcohol towards Next-Generation Nerve Conduits Development." Polymers 13, no. 19 (September 30, 2021): 3372. http://dx.doi.org/10.3390/polym13193372.
Full textAbstract:
The limitations and difficulties that nerve autografts create in normal nerve function recovery after injury is driving research towards using smart materials for next generation nerve conduits (NCs) setup. Here, the new polymer partially oxidized polyvinyl alcohol (OxPVA) was assayed to verify its future potential as a bioactivated platform for advanced/effective NCs. OxPVA-patterned scaffolds (obtained by a 3D-printed mold) with/without biochemical cues (peptide IKVAV covalently bound (OxPVA-IKVAV) or self-assembling peptide EAK (sequence: AEAEAKAKAEAEAKAK), mechanically incorporated (OxPVA+EAK) versus non-bioactivated scaffold (peptide-free OxPVA (PF-OxPVA) supports, OxPVA without IKVAV and OxPVA without EAK control scaffolds) were compared for their biological effect on neuronal SH-SY5Y cells. After cell seeding, adhesion/proliferation, mediated by (a) precise control over scaffolds surface ultrastructure; (b) functionalization efficacy guaranteed by bioactive cues (IKVAV/EAK), was investigated by MTT assay at 3, 7, 14 and 21 days. As shown by the results, the patterned groove alone stimulates colonization by cells; however, differences were observed when comparing the scaffold types over time. In the long period (21 days), patterned OxPVA+EAK scaffolds distinguished in bioactivity, assuring a significantly higher total cell amount than the other groups. Experimental evidence suggests patterned OxPVA-EAK potential for NCs device fabrication.
26
Zahn, Ingrid, Daniel David Stöbener, Marie Weinhart, Clemens Gögele, Annette Breier, Judith Hahn, Michaela Schröpfer, Michael Meyer, and Gundula Schulze-Tanzil. "Cruciate Ligament Cell Sheets Can Be Rapidly Produced on Thermoresponsive poly(glycidyl ether) Coating and Successfully Used for Colonization of Embroidered Scaffolds." Cells 10, no. 4 (April 12, 2021): 877. http://dx.doi.org/10.3390/cells10040877.
Full textAbstract:
Anterior cruciate ligament (ACL) cell sheets combined with biomechanically competent scaffolds might facilitate ACL tissue engineering. Since thermoresponsive polymers allow a rapid enzyme-free detachment of cell sheets, we evaluated the applicability of a thermoresponsive poly(glycidyl ether) (PGE) coating for cruciate ligamentocyte sheet formation and its influence on ligamentocyte phenotype during sheet-mediated colonization of embroidered scaffolds. Ligamentocytes were seeded on surfaces either coated with PGE or without coating. Detached ligamentocyte sheets were cultured separately or wrapped around an embroidered scaffold made of polylactide acid (PLA) and poly(lactic-co-ε-caprolactone) (P(LA-CL)) threads functionalized by gas-phase fluorination and with collagen foam. Ligamentocyte viability, protein and gene expression were determined in sheets detached from surfaces with or without PGE coating, scaffolds seeded with sheets from PGE-coated plates and the respective monolayers. Stable and vital ligamentocyte sheets could be produced within 24 h with both surfaces, but more rapidly with PGE coating. PGE did not affect ligamentocyte phenotype. Scaffolds could be colonized with sheets associated with high cell survival, stable gene expression of ligament-related type I collagen, decorin, tenascin C and Mohawk after 14 d and extracellular matrix (ECM) deposition. PGE coating facilitates ligamentocyte sheet formation, and sheets colonizing the scaffolds displayed a ligament-related phenotype.
27
Szychlinska, Marta Anna, Giovanna Calabrese, Silvia Ravalli, Anna Dolcimascolo, Paola Castrogiovanni, Claudia Fabbi, Caterina Puglisi, et al. "Evaluation of a Cell-Free Collagen Type I-Based Scaffold for Articular Cartilage Regeneration in an Orthotopic Rat Model." Materials 13, no. 10 (May 21, 2020): 2369. http://dx.doi.org/10.3390/ma13102369.
Full textAbstract:
The management of chondral defects represents a big challenge because of the limited self-healing capacity of cartilage. Many approaches in this field obtained partial satisfactory results. Cartilage tissue engineering, combining innovative scaffolds and stem cells from different sources, emerges as a promising strategy for cartilage regeneration. The aim of this study was to evaluate the capability of a cell-free collagen I-based scaffold to promote cartilaginous repair after orthotopic implantation in vivo. Articular cartilage lesions (ACL) were created at the femoropatellar groove in rat knees and cell free collagen I-based scaffolds (S) were then implanted into right knee defect for the ACL-S group. No scaffold was implanted for the ACL group. At 4-, 8- and 16-weeks post-transplantation, degrees of cartilage repair were evaluated by morphological, histochemical and gene expression analyses. Histological analysis shows the formation of fibrous tissue, at 4-weeks replaced by a tissue resembling the calcified one at 16-weeks in the ACL group. In the ACL-S group, progressive replacement of the scaffold with the newly formed cartilage-like tissue is shown, as confirmed by Alcian Blue staining. Immunohistochemical and quantitative real-time PCR (qRT-PCR) analyses display the expression of typical cartilage markers, such as collagen type I and II (ColI and ColII), Aggrecan and Sox9. The results of this study display that the collagen I-based scaffold is highly biocompatible and able to recruit host cells from the surrounding joint tissues to promote cartilaginous repair of articular defects, suggesting its use as a potential approach for cartilage tissue regeneration.
28
Li, Lan, Jiayi Li, Jiamin Guo, Huikang Zhang, Xin Zhang, Caiyun Yin, Liming Wang, Yishen Zhu, and Qingqiang Yao. "3D Molecularly Functionalized Cell‐Free Biomimetic Scaffolds for Osteochondral Regeneration." Advanced Functional Materials 29, no. 6 (December 6, 2018): 1807356. http://dx.doi.org/10.1002/adfm.201807356.
Full text
29
Vaiselbuh, Sarah Rivkah, Morris Edelman, Jeffrey Michael Lipton, and Johnson M. Liu. "Ectopic Human Mesenchymal Stem Cell-Coated Scaffolds Create An In Vivo Leukemia Niche in NOD/SCID Mice." Blood 114, no. 22 (November 20, 2009): 559. http://dx.doi.org/10.1182/blood.v114.22.559.559.
Full textAbstract:
Abstract Abstract 559 Introduction: Different cellular components of the normal hematopoietic niche have been identified. However, the niche for malignant hematopoiesis remains to be elucidated. Recent work of other groups has suggested that hematopoietic stem cells (HSC) within the bone marrow anchor themselves in place by attaching to osteoblasts and/or vascular sinusoid endothelial cells. We have recently identified mesenchymal stem cells (MSC) as niche-maker cells and found a crucial role of the SDF-1/CXCR4 axis in this process. Stromal Derived Factor-1 (SDF-1/CXCL12) regulates stem cell trafficking and the cell cycle via its receptor CXCR4. Methods: Polyurethane scaffolds, coated in vitro with human bone marrow MSC, were implanted subcutaneously in non-irradiated NOD/SCID mice. CD34+ HSC or primary AML cells (from a leukapheresis product) were injected either in situ or retro-orbitally in the mice and analyzed for engraftment. The mice were treated twice per week with in situ injections of SDF-1, AMD3100 (a CXCR4 antagonist) or PBS (control). After 2 to 4 weeks, the scaffolds were processed and evaluated for cell survival in the mesenchymal niche by immunohistochemistry. Results: We created in vitro MSC-coated scaffolds that retained inoculated AML cells in the presence of SDF-1, while AML cells seeded on empty scaffolds were not retained. In vivo in NOD/SCID mice, the MSC-coated scaffolds, in the presence of SDF-1 enabled homing of both in situ injected normal CD34+ HSC and retroorbital- or in situ injected primary human AML cells. The scaffolds were vascularized and showed osteoclasts and adipocytes present, suggestive of an ectopic human bone marrow microenvironment in the murine host. Finally, the SDF-1-treated scaffolds showed proliferation of the MSC stromal layer with multiple adherent AML cells, while in the AMD3100-treated scaffolds the stromal lining was thin and disrupted at several points, leaving AML cells free floating in proximity. The PBS-treated control-scaffold showed a thin single cell MSC stromal layer without disruption, with few AML cells attached. Conclusion: The preliminary data of this functional ectopic human microenvironment in NOD/SCID mice suggest that AMD3100 (a CXCR4 antagonist) can disrupt the stem cell niche by modulation of the mesenchymal stromal. Further studies are needed to define the role of mesenchymal stem cells in maintaining the hematopoietic/leukemic stem cell niche in vivo. In Vivo Leukemia Stem Cell Niche: (A) Empty polyurethane scaffold. (B)Vascularization in SQ implanted MSC-coated scaffold (s) niche in NOD/SCID mice. (C) DAB Peroxidase (brown) human CD45 positive nests of AML cells (arrows) 1 week after direct in situ AML injection. (D) Human CD45 positive myeloid cells adhere to MSC in vivo (arrows). Disclosures: No relevant conflicts of interest to declare.
30
Crovace, Alberto M., Alessia Di Giancamillo, Francesca Gervaso, Laura Mangiavini, Davide Zani, Francesca Scalera, Barbara Palazzo, et al. "Evaluation of in Vivo Response of Three Biphasic Scaffolds for Osteochondral Tissue Regeneration in a Sheep Model." Veterinary Sciences 6, no. 4 (November 9, 2019): 90. http://dx.doi.org/10.3390/vetsci6040090.
Full textAbstract:
Osteochondral defects are a common problem in both human medicine and veterinary practice although with important limits concerning the cartilaginous tissue regeneration. Interest in the subchondral bone has grown, as it is now considered a key element in the osteochondral defect healing. The aim of this work was to generate and to evaluate the architecture of three cell-free scaffolds made of collagen, magnesium/hydroxyapatite and collagen hydroxyapatite/wollastonite to be implanted in a sheep animal model. Scaffolds were designed in a bilayer configuration and a novel “Honey” configuration, where columns of hydroxyapatite were inserted within the collagen matrix. The use of different types of scaffolds allowed us to identify the best scaffold in terms of integration and tissue regeneration. The animals included were divided into four groups: three were treated using different types of scaffold while one was left untreated and represented the control group. Evaluations were made at 3 months through CT analysis. The novel “Honey” configuration of the scaffold with hydroxyapatite seems to allow for a better reparative process, although we are still far from obtaining a complete restoration of the defect at this time point of follow-up.
31
Allafchian, Alireza, Shiva Saeedi, and Seyed Amir Hossein Jalali. "Biocompatibility of electrospun cell culture scaffolds made from balangu seed mucilage/PVA composites." Nanotechnology 33, no. 7 (November 25, 2021): 075302. http://dx.doi.org/10.1088/1361-6528/ac3860.
Full textAbstract:
Abstract Synthesis of Balangu (Lallemantia royleana) seed mucilage (BSM) solutions combined with polyvinyl alcohol (PVA) was studied for the purpose of producing 3D electrospun cell culture scaffolds. Production of pure BSM nanofibers proved to be difficult, yet integration of PVA contributed to a facile and successful formation of BSM/PVA nanofibers. Different BSM/PVA ratios were fabricated to achieve the desired nanofibrous structure for cell proliferation. It is found that the optimal bead-free ratio of 50/50 with a mean fiber diameter of ≈180 nm presents the most desirable scaffold structure for cell growth. The positive effect of PVA incorporation was approved by analyzing BSM/PVA solutions through physiochemical assays such as electrical conductivity, viscosity and surface tension tests. According to the thermal analysis (TGA/DSC), incorporation of PVA enhanced thermal stability of the samples. Successful fabrication of the nanofibers is verified by FT-IR spectra, where no major chemical interaction between BSM and PVA is detected. The crystallinity of the electrospun nanofibers is investigated by XRD, revealing the nearly amorphous structure of BSM/PVA scaffolds. The MTT assay is employed to verify the biocompatibility of the scaffolds. The cell culture experiment using epithelial Vero cells shows the affinity of the cells to adhere to their nanofibrous substrate and grow to form continuous cell layers after 72 h of incubation.
32
LaBarge, Wesley, Andrés Morales, Daniëlle Pretorius, Asher Kahn-Krell, Ramaswamy Kannappan, and Jianyi Zhang. "Scaffold-Free Bioprinter Utilizing Layer-By-Layer Printing of Cellular Spheroids." Micromachines 10, no. 9 (August 29, 2019): 570. http://dx.doi.org/10.3390/mi10090570.
Full textAbstract:
Free from the limitations posed by exogenous scaffolds or extracellular matrix-based materials, scaffold-free engineered tissues have immense clinical potential. Biomaterials may produce adverse responses, interfere with cell–cell interaction, or affect the extracellular matrix integrity of cells. The scaffold-free Kenzan method can generate complex tissues using spheroids on an array of needles but could be inefficient in terms of time, as it moves and places only a single spheroid at a time. We aimed to design and construct a novel scaffold-free bioprinter that can print an entire layer of spheroids at once, effectively reducing the printing time. The bioprinter was designed using computer-aided design software and constructed from machined, 3D printed, and commercially available parts. The printing efficiency and the operating precision were examined using Zirconia and alginate beads, which mimic spheroids. In less than a minute, the printer could efficiently pick and transfer the beads to the printing surface and assemble them onto the 4 × 4 needles. The average overlap coefficient between layers was measured and found to be 0.997. As a proof of concept using human induced pluripotent stem cell-derived spheroids, we confirmed the ability of the bioprinter to place cellular spheroids onto the needles efficiently to print an entire layer of tissue. This novel layer-by-layer, scaffold-free bioprinter is efficient and precise in operation and can be easily scaled to print large tissues.
33
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.
Full textAbstract:
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.
34
Isaeva, Elena V., Evgeny E. Beketov, Grigory A. Demyashkin, Nina D. Yakovleva, Nadezhda V. Arguchinskaya, Anastas A. Kisel, Tatiana S. Lagoda, et al. "Cartilage Formation In Vivo Using High Concentration Collagen-Based Bioink with MSC and Decellularized ECM Granules." International Journal of Molecular Sciences 23, no. 5 (February 28, 2022): 2703. http://dx.doi.org/10.3390/ijms23052703.
Full textAbstract:
The aim of this study was to verify the applicability of high-concentration collagen-based bioink with MSC (ADSC) and decellularized ECM granules for the formation of cartilage tissue de novo after subcutaneous implantation of the scaffolds in rats. The printability of the bioink (4% collagen, 2.5% decellularized ECM granules, derived via 280 μm sieve) was shown. Three collagen-based compositions were studied: (1) with ECM; (2) with MSC; (3) with ECM and MSC. It has been established that decellularized ECM granules are able to stimulate chondrogenesis both in cell-free and MSC-laden scaffolds. Undesirable effects have been identified: bone formation as well as cartilage formation outside of the scaffold area. The key perspectives and limitations of ECM granules (powder) application have been discussed.
35
Barone, Ludovica, Federica Rossi, Luigi Valdatta, Mario Cherubino, Roberto Papait, Giorgio Binelli, Nicla Romano, Giovanni Bernardini, and Rosalba Gornati. "Human Adipose-Derived Stem Cell-Conditioned Medium Promotes Vascularization of Nanostructured Scaffold Transplanted into Nude Mice." Nanomaterials 12, no. 9 (April 30, 2022): 1521. http://dx.doi.org/10.3390/nano12091521.
Full textAbstract:
Several studies have been conducted on the interaction between three-dimensional scaffolds and mesenchymal stem cells for the regeneration of damaged tissues. Considering that stem cells do not survive for sufficient time to directly sustain tissue regeneration, it is essential to develop cell-free systems to be applied in regenerative medicine. In this work, by in vivo experiments, we established that a collagen-nanostructured scaffold, loaded with a culture medium conditioned with mesenchymal stem cells derived from adipose tissue (hASC-CM), exerts a synergic positive effect on angiogenesis, fundamental in tissue regeneration. To this aim, we engrafted athymic BALB-C nude mice with four different combinations: scaffold alone; scaffold with hASCs; scaffold with hASC crude protein extract; scaffold with hASC-CM. After their removal, we verified the presence of blood vessels by optical microscopy and confirmed the vascularization evaluating, by real-time PCR, several vascular growth factors: CD31, CD34, CD105, ANGPT1, ANGPT2, and CDH5. Our results showed that blood vessels were absent in the scaffold grafted alone, while all the other systems appeared vascularized, a finding supported by the over-expression of CD31 and CDH5 mRNA. In conclusion, our data sustain the capability of hASC-CM to be used as a therapeutic cell-free approach for damaged tissue regeneration.
36
Vasanthan, Kirthanashri S., Varadharajan Srinivasan, and Deepti Pandita. "Extracellular matrix extraction techniques and applications in biomedical engineering." Regenerative Medicine 16, no. 8 (August 2021): 775–802. http://dx.doi.org/10.2217/rme-2021-0021.
Full textAbstract:
The concept of tissue engineering involves regeneration and repair of damaged tissue and organs using various combinations of cells, growth factors and scaffolds. The extracellular matrix (ECM) forms the integral part of the scaffold to induce cell proliferation thereby leading to new tissue formation. Decellularization technique provides decellularized ECM (dECM), free of cells while preserving the in vivo biomolecules. In this review, we focus on the detailed methodology of diverse decellularization techniques for various organs of different animals, and the biomedical applications employing the dECM. A culmination of different methods of decellularization is optimized, which offers a suitable microenvironment mimicking the native in vivo topography for in vitro organ regeneration. A detailed assessment of the dECM provides information on the microarchitecture, presence of ECM proteins, biocompatibility and cell proliferation. dECM has also been processed as scaffolds and drug-delivery vehicles, and utilized for regeneration.
37
Li, Lan, Jiayi Li, Jiamin Guo, Huikang Zhang, Xin Zhang, Caiyun Yin, Liming Wang, Yishen Zhu, and Qingqiang Yao. "Biomimetic Scaffolds: 3D Molecularly Functionalized Cell‐Free Biomimetic Scaffolds for Osteochondral Regeneration (Adv. Funct. Mater. 6/2019)." Advanced Functional Materials 29, no. 6 (February 2019): 1970036. http://dx.doi.org/10.1002/adfm.201970036.
Full text
38
Mortera-Blanco, Teresa, Athanasios Mantalaris, Alexander Bismarck, and Nicki Panoskaltsis. "Long-Term in Vitro Cytokine-Free and Serum-Free Culture of Human Cord Blood Mononuclear Cells in a Three-Dimensional Scaffold." Blood 114, no. 22 (November 20, 2009): 503. http://dx.doi.org/10.1182/blood.v114.22.503.503.
Full textAbstract:
Abstract Abstract 503 The ability to expand cord blood (CB) cells ex vivo overcomes an important limitation to its wider clinical application in cellular therapies. The current practice of hematopoietic cell culture is based on two-dimensional (2D) tissue culture flasks or well plates which require either co-culture with allogeneic or xenogeneic stromal cells and the exogenous provision of several cytokines. This 2D culture environment is artificial and lacks the 3D cellular niches that characterise the in vivo hematopoietic inductive microenvironment. Specifically, the cultured cells are exposed to abnormally high cytokine concentrations, which may result in differentiation and loss of pluripotency. We have previously developed a 3D bone marrow biomimicry through the use of synthetic scaffolds made of poly (D,L-lactide-co-glycolide) (PLGA) and polyurethane (PU) coated with collagen type I. Our previous work has shown that these scaffolds, which were seeded with cord blood (CB) mononuclear cells (MNCs) at a cell density of 3-6×106cells per scaffold (5×5×5mm3), could successfully support long-term culture in the absence of exogenous growth factors for over 4 weeks. Specifically, the 3D biomimicry facilitated a 53-fold total MNC expansion, with an increase in the BFU-E and CFU-GM progenitor cell population. However, these cultures, although cytokine-free, contained 20-30% (v/v) fetal calf serum which can have both conducive and inhibitory effects on hematopoietic cell cultures due to the unknown composition and concentration of humoral factors contained within. Inclusion of serum in expansion-type cultures can limit the clinical application of the derived product. The serum-free and cytokine-free culture and expansion of hematopoietic cells has not been achieved until now. Herein, we report that for at least 4 weeks the polyurethane (PU) scaffolds coated with collagen type I were able to maintain and expand human CB MNCs. Furthermore the progenitor population, as determined by the colony forming unit assay, was also maintained and preferentially directed towards the granulocytic lineage, even though the CFU-GEMMs declined. Immunophenotypic analysis of the extracted cells confirmed the presence of erythroid precursors (CD71+CD45-) as well as early maturing myeloid cells. In contrast, the 2D cytokine- and serum-free cultures collapsed within 3-4 days. We hypothesized that the 3D biomimicry was able to facilitate serum- and cytokine-free conditions because it can recapitulate the three-dimensional architecture of the human bone marrow. This hypothesis was supported by scanning electron microscopy of the central sections of the scaffolds that showed the migration of cells within the pores and establishment of “niche-like” structures. In conclusion, this novel 3D culture system is capable of long-term, cytokine- and serum-free expansion of haematopoietic cells from cord blood, enabling the study of haematopoiesis as well as facilitating the expansion of cells for future clinical applications. Disclosures: No relevant conflicts of interest to declare.
39
Blanco, Teresa Mortera, Athanasios Mantalaris, Joseph Santiapillai, Alexander Bismarck, and Nicki Panoskaltsis. "Effects of Single-Agent, Low Dose Exogenous Erythropoietin In a Long-Term In Vitro serum-Free 3D Culture of Human Cord Blood Mononuclear Cells for Directed Erythropoiesis." Blood 116, no. 21 (November 19, 2010): 341. http://dx.doi.org/10.1182/blood.v116.21.341.341.
Full textAbstract:
Abstract Abstract 341 Ex vivo expansion of cord blood mononuclear cells (CBMNCs) could provide a safe, flexible and ample supply of blood components for cellular therapies. Traditionally, hematopoietic cell expansion has been performed in 2D tissue culture flask or well-plate static cultures using abnormally high concentrations of cytokines which is expensive, reduces the self-renewal capacity, and skews normal differentiation. We have previously developed a 3D bone marrow biomimicry through the use of a synthetic scaffold made of polyurethane (PU) coated with collagen type I which could expand CBMNCs in a cytokine-free environment for at least 28 days ex vivo, with or without the addition of serum to the media. We hypothesised that the addition of near physiological concentrations (0.2U/mL and 1.845U/mL) of exogenous erythropoietin (EPO) to these established 3D CBMNC ex vivo cultures at day 14 in a serum-free and cytokine-free environment would be sufficient to enhance erythropoiesis. CBMNCs were separated by Ficoll-Paque density gradient and seeded onto collagen-coated PU 3D scaffolds at a cell density of 2.5×106cells per scaffold (5×5×5mm3). Cultures were established in serum-free conditions and only EPO was added at days 14–28, with full-medium exchange every 2 days. Culture output was evaluated at days 14, 21 and 28 both by physically extracting cells from the scaffolds and by in situ analysis. Over 28 days, most stages of maturation, from erythroid progenitors to enucleated erythrocytes were observed by light microscopy of cytospins and by immunophenotypic analysis of extracted cells (CD45−/CD71+/CD235+), with more maturation occurring by day 28 of culture, after the addition of EPO. Although both concentrations of EPO produced comparable erythroid differentiation of cells, even by CFU assay, the viability (75% vs. 61%, p<0.05) and proliferative capacity at day 28 of culture was enhanced in the higher concentration of EPO compared with that in the lower concentration (p<0.05). In contrast, standard 2D control cultures (without serum or cytokines) collapsed within 5 days. In situ, scanning electron microscopy showed maturation of erythrocytes within central sections of the scaffolds to enucleation by day 28 and multiphoton microscopy confirmed the presence of structures resembling erythroid islands as early as day 14 of culture, prior to the addition of EPO. In conclusion, 3D PU-collagen scaffolds may provide a good model to study erythropoiesis ex vivo, using physiological concentrations of EPO, and has the potential to expand red cells in response to higher levels of exogenous EPO in a culture system that would be suitable for clinical applications. Disclosures: No relevant conflicts of interest to declare.
40
Gapska, Paulina, and Maciej Kurpisz. "Perspective in optimization of stem cell therapies for heart regeneration." Postępy Higieny i Medycyny Doświadczalnej 71 (December 7, 2017): 0. http://dx.doi.org/10.5604/01.3001.0010.6665.
Full textAbstract:
There is a variety of mechanisms(s) factor(s) that may influence stem cell therapies for heart regeneration. Among the best candidates for stem cell source are: mesenchymal stem cells (also those isolated from adipose tissue), cardiac cell progenitors (CPC) and descendants of iPSC cells. iPSC/s can be potentially beneficial although their pluripotent induction has been still in question due to: low propagation efficacy, danger of genomic integration/instability, biological risk of current vector system teratoma formation etc. which have been discussed in this review. Optimization protocols are required in order to enhance stem cells resistance to pathological conditions that they may encounter in pathological organ and to increase their retention. Combination between gene transfer and stem cell therapy is now more often used in pre-clinical studies with the prospect of subsequent clinical trials. Complementary substances have been contemplated to support stem cell viability (mainly anti-inflammatory and anti- apoptotic agents), which have been tested in animal models with promising results. Integration of nanotechnology both for efficient stem cell imaging as well as with the aim to provide cell supporting scaffolds seem to be inevitable for further development of cellular therapies. The whole organ (heart) reconstruction as well as biodegradable scaffolds and scaffold-free cell sheets have been also outlined.
41
Lou, Ching Wen, Shih Peng Wen, Wen Cheng Chen, Yueh Sheng Chen, and Jia Horng Lin. "The Freeze-Dry Method and In Vitro Assay of Chitosan/Gelatin/Hydroxyapatite Artificial Bone Scaffolds." Applied Mechanics and Materials 749 (April 2015): 441–44. http://dx.doi.org/10.4028/www.scientific.net/amm.749.441.
Full textAbstract:
This study aims to create avirulent artificial bone scaffolds. Chitosan/gelatin mixture is blended with hydroxyapatite (HA) powder, followed by being processed with a free-dry method in order to form CGH artificial bone scaffolds. A stereomicroscope, an optical microscope and an MTT assay are used to evaluate the applications of the bone scaffolds. The combination of HA powders leads to isotropic pores in the bone scaffolds, while not inflicting their biocompatibility. In addition, the cell viability increases with the increasing content of HA powder. This study successfully produces biocompatible and non-toxic bone scaffolds.
42
Okawa, Hiroko, Hiroki Kayashima, Jun-Ichi Sasaki, Jiro Miura, Yuya Kamano, Yukihiro Kosaka, Satoshi Imazato, Hirofumi Yatani, Takuya Matsumoto, and Hiroshi Egusa. "Scaffold-Free Fabrication of Osteoinductive Cellular Constructs Using Mouse Gingiva-Derived Induced Pluripotent Stem Cells." Stem Cells International 2016 (2016): 1–11. http://dx.doi.org/10.1155/2016/6240794.
Full textAbstract:
Three-dimensional (3D) cell constructs are expected to provide osteoinductive materials to develop cell-based therapies for bone regeneration. The proliferation and spontaneous aggregation capability of induced pluripotent stem cells (iPSCs) thus prompted us to fabricate a scaffold-free iPSC construct as a transplantation vehicle. Embryoid bodies of mouse gingival fibroblast-derived iPSCs (GF-iPSCs) were seeded in a cell chamber with a round-bottom well made of a thermoresponsive hydrogel. Collected ball-like cell constructs were cultured in osteogenic induction medium for 30 days with gentle shaking, resulting in significant upregulation of osteogenic marker genes. The constructs consisted of an inner region of unstructured cell mass and an outer osseous tissue region that was surrounded by osteoblast progenitor-like cells. The outer osseous tissue was robustly calcified with elemental calcium and phosphorous as well as hydroxyapatite. Subcutaneous transplantation of the GF-iPSC constructs into immunodeficient mice contributed to extensive ectopic bone formation surrounded by teratoma tissue. These results suggest that mouse GF-iPSCs could facilitate the fabrication of osteoinductive scaffold-free 3D cell constructs, in which the calcified regions and surrounding osteoblasts may function as scaffolds and drivers of osteoinduction, respectively. With incorporation of technologies to inhibit teratoma formation, this system could provide a promising strategy for bone regenerative therapies.
43
Hammerl, Andreas, Carlos Diaz Cano, Elena De-Juan-Pardo, Martijn van Griensven, and Patrina Poh. "A Growth Factor-Free Co-Culture System of Osteoblasts and Peripheral Blood Mononuclear Cells for the Evaluation of the Osteogenesis Potential of Melt-Electrowritten Polycaprolactone Scaffolds." International Journal of Molecular Sciences 20, no. 5 (March 1, 2019): 1068. http://dx.doi.org/10.3390/ijms20051068.
Full textAbstract:
Scaffolds made of biodegradable biomaterials are widely used to guide bone regeneration. Commonly, in vitro assessment of scaffolds’ osteogenesis potential has been performed predominantly in monoculture settings. Hence, this study evaluated the potential of an unstimulated, growth factor-free co-culture system comprised of osteoblasts (OB) and peripheral blood mononuclear cells (PBMC) over monoculture of OB as an in vitro platform for screening of bone regeneration potential of scaffolds. Particularly, this study focuses on the osteogenic differentiation and mineralized matrix formation aspects of cells. The study was performed using scaffolds fabricated by means of a melt electrowriting (MEW) technique made of medical-grade polycaprolactone (PCL), with or without a surface coating of calcium phosphate (CaP). Qualitative results, i.e., cell morphology by fluorescence imaging and matrix mineralization by von Kossa staining, indicated the differences in cell behaviours in response to scaffolds’ biomaterial. However, no obvious differences were noted between OB and OB+PBMC groups. Hence, quantitative investigation, i.e., alkaline phosphatase (ALP), tartrate-resistant acid phosphatase (TRAP) activities, and gene expression were quantitatively evaluated by reverse transcription-polymerase chain reaction (RT-qPCR), were evaluated only of PCL/CaP scaffolds cultured with OB+PBMC, while PCL/CaP scaffolds cultured with OB or PBMC acted as a control. Although this study showed no differences in terms of osteogenic differentiation and ECM mineralization, preliminary qualitative results indicate an obvious difference in the cell/non-mineralized ECM density between scaffolds cultured with OB or OB+PBMC that could be worth further investigation. Collectively, the unstimulated, growth factor-free co-culture (OB+PBMC) system presented in this study could be beneficial for the pre-screening of scaffolds’ in vitro bone regeneration potential prior to validation in vivo.
44
Noda, Tomoka, Mayumi Hatakeyama, and Takuya Kitaoka. "Combination of Polysaccharide Nanofibers Derived from Cellulose and Chitin Promotes the Adhesion, Migration and Proliferation of Mouse Fibroblast Cells." Nanomaterials 12, no. 3 (January 26, 2022): 402. http://dx.doi.org/10.3390/nano12030402.
Full textAbstract:
Extracellular matrix (ECM) as a structural and biochemical scaffold to surrounding cells plays significant roles in cell adhesion, migration, proliferation and differentiation. Herein, we show the novel combination of TEMPO-oxidized cellulose nanofiber (TOCNF) and surface-N-deacetylated chitin nanofiber (SDCtNF), respectively, having carboxylate and amine groups on each crystalline surface, for mouse fibroblast cell culture. The TOCNF/SDCtNF composite scaffolds demonstrated characteristic cellular behavior, strongly depending on the molar ratios of carboxylates and amines of polysaccharide NFs. Pure TOCNF substrate exhibited good cell attachment, although intact carboxylate-free CNF made no contribution to cell adhesion. By contrast, pure SDCtNF induced crucial cell aggregation to form spheroids; nevertheless, the combination of TOCNF and SDCtNF enhanced cell attachment and subsequent proliferation. Molecular blend of carboxymethylcellulose and acid-soluble chitosan made nearly no contribution to cell culture behavior. The wound healing assay revealed that the polysaccharide combination markedly promoted skin repair for wound healing. Both of TOCNF and SDCtNF possessed rigid nanofiber nanoarchitectures with native crystalline forms and regularly-repeated functional groups, of which such structural characteristics would provide a potential for developing cell culture scaffolds having ECM functions, possibly promoting good cellular adhesion, migration and growth in the designated cellular microenvironments.
45
Muylaert, Dimitri EP, Joost O. Fledderus, Carlijn VC Bouten, Patricia YW Dankers, and Marianne C. Verhaar. "Combining tissue repair and tissue engineering; bioactivating implantable cell-free vascular scaffolds." Heart 100, no. 23 (July 22, 2014): 1825–30. http://dx.doi.org/10.1136/heartjnl-2014-306092.
Full text
46
Xuan, Huixia, Haoran Hu, Congying Geng, Jianchun Song, Yifan Shen, Dong Lei, Qingbao Guan, Shichang Zhao, and Zhengwei You. "Biofunctionalized chondrogenic shape-memory ternary scaffolds for efficient cell-free cartilage regeneration." Acta Biomaterialia 105 (March 2020): 97–110. http://dx.doi.org/10.1016/j.actbio.2020.01.015.
Full text
47
Hao, Li, Zhao Tianyuan, Yang Zhen, Cao Fuyang, Wu Jiang, Yan Zineng, Ding Zhengang, et al. "Biofabrication of cell-free dual drug-releasing biomimetic scaffolds for meniscal regeneration." Biofabrication 14, no. 1 (October 18, 2021): 015001. http://dx.doi.org/10.1088/1758-5090/ac2cd7.
Full text
48
Olaru, Mihaela, Liliana Sachelarie, and Gabriela Calin. "Hard Dental Tissues Regeneration—Approaches and Challenges." Materials 14, no. 10 (May 14, 2021): 2558. http://dx.doi.org/10.3390/ma14102558.
Full textAbstract:
With the development of the modern concept of tissue engineering approach and the discovery of the potential of stem cells in dentistry, the regeneration of hard dental tissues has become a reality and a priority of modern dentistry. The present review reports the recent advances on stem-cell based regeneration strategies for hard dental tissues and analyze the feasibility of stem cells and of growth factors in scaffolds-based or scaffold-free approaches in inducing the regeneration of either the whole tooth or only of its component structures.
49
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.
Full textAbstract:
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.
50
Hausherr, Tanja C., Katja Nuss, Eric Thein, Lee A. Applegate, and Dominique P. Pioletti. "Human Bone Progenitor Cells for Clinical Application: What Kind of Immune Reaction Does Fetal Xenograft Tissue Trigger in Immunocompetent Rats?" Cell Transplantation 26, no. 5 (May 2017): 879–90. http://dx.doi.org/10.3727/096368916x693789.
Full textAbstract:
The potential of human fetal bone cells for successful bone regeneration has been shown in vivo. In particular, it has been demonstrated that the seeding of these cells in porous poly-(L-lactic acid)/β-tricalcium phosphate scaffolds improved the bone formation compared to cell-free scaffolds in skulls of rats. However, even if the outcome is an improvement of bone formation, a thorough analysis concerning any immune responses, due to the implantation of a xenograft tissue, is not known. As the immune response and skeletal system relationship may contribute to either the success or failure of an implant, we were interested in evaluating the presence of any immune cells and specific reactions of human fetal cells (also called human bone progenitor cells) once implanted in femoral condyles of rats. For this purpose, (1) cell-free scaffolds, (2) human bone progenitor cells, or (3) osteogenic human bone progenitor cells within scaffolds were implanted over 3, 7, 14 days, and 12 weeks. The key finding is that human bone progenitor cells and osteogenic human bone progenitor cells do not trigger any particular specific immune reactions in immunocompetent rats but are noted to delay some bone formation.