Academic literature on the topic 'Bio-scaffold'
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Journal articles on the topic "Bio-scaffold"
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Rohman, Géraldine, Credson Langueh, Salah Ramtani, Jean-Jacques Lataillade, Didier Lutomski, Karim Senni, and Sylvie Changotade. "The Use of Platelet-Rich Plasma to Promote Cell Recruitment into Low-Molecular-Weight Fucoidan-Functionalized Poly(Ester-Urea-Urethane) Scaffolds for Soft-Tissue Engineering." Polymers 11, no. 6 (June 9, 2019): 1016. http://dx.doi.org/10.3390/polym11061016.
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Due to their elastomeric behavior, polyurethane-based scaffolds can find various applications in soft-tissue engineering. However, their relatively inert surface has to be modified in order to improve cell colonization and control cell fate. The present study focuses on porous biodegradable scaffolds based on poly(ester-urea-urethane), functionalized concomitantly to the scaffold elaboration with low-molecular-weight (LMW) fucoidan; and their bio-activation with platelet rich plasma (PRP) formulations with the aim to promote cell response. The LMW fucoidan-functionalization was obtained in a very homogeneous way, and was stable after the scaffold sterilization and incubation in phosphate-buffered saline. Biomolecules from PRP readily penetrated into the functionalized scaffold, leading to a biological frame on the pore walls. Preliminary in vitro assays were assessed to demonstrate the improvement of scaffold behavior towards cell response. The scaffold bio-activation drastically improved cell migration. Moreover, cells interacted with all pore sides into the bio-activated scaffold forming cell bridges across pores. Our work brought out an easy and versatile way of developing functionalized and bio-activated elastomeric poly(ester-urea-urethane) scaffolds with a better cell response.
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Chen, Xiao Feng, Ying Jun Wang, Na Ru Zhao, and Chun Rong Yang. "Investigation on the Biomimetic Scaffold for Bone Tissue Engineering Based on Bioglass-Collagen-Hyaluronic Acid-Phosphatidylserine." Key Engineering Materials 330-332 (February 2007): 939–42. http://dx.doi.org/10.4028/www.scientific.net/kem.330-332.939.
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The new type of bone tissue engineering scaffold composed of the sol-gel derived bioactive glass particles, type I collagen, hyaluronic acid and phosphatidylserine were prepared through cross-linking and freeze-drying techniques. SEM observation indicated that the scaffold possessed a 3-D interconnected porous structure and a high porosity. The properties of bio-mineralization and cells biocompatibility were investigated using SBF immersion and cells culture methods combined with SEM, XRD and FTIR techniques. The study revealed that this biomimetic scaffold possessed satisfactory functions of cells attachment, bio-mineralization, and cells biocompatibility. The porous structure and the surface of the scaffold which was covered by a bone-like HA crystal layer due to bio-mineralization were profitable for cells attachment and spread.
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Hu, Xueyan, Yuan Man, Wenfang Li, Liying Li, Jie Xu, Roxanne Parungao, Yiwei Wang, et al. "3D Bio-Printing of CS/Gel/HA/Gr Hybrid Osteochondral Scaffolds." Polymers 11, no. 10 (September 30, 2019): 1601. http://dx.doi.org/10.3390/polym11101601.
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Cartilage is an important tissue contributing to the structure and function of support and protection in the human body. There are many challenges for tissue cartilage repair. However, 3D bio-printing of osteochondral scaffolds provides a promising solution. This study involved preparing bio-inks with different proportions of chitosan (Cs), Gelatin (Gel), and Hyaluronic acid (HA). The rheological properties of each bio-ink was used to identify the optimal bio-ink for printing. To improve the mechanical properties of the bio-scaffold, Graphene (GR) with a mass ratio of 0.024, 0.06, and 0.1% was doped in the bio-ink. Bio-scaffolds were prepared using 3D printing technology. The mechanical strength, water absorption rate, porosity, and degradation rate of the bio-scaffolds were compared to select the most suitable scaffold to support the proliferation and differentiation of cells. P3 Bone mesenchymal stem cells (BMSCs) were inoculated onto the bio-scaffolds to study the biocompatibility of the scaffolds. The results of SEM showed that the Cs/Gel/HA scaffolds with a GR content of 0, 0.024, 0.06, and 0.1% had a good three-dimensional porous structure and interpenetrating pores, and a porosity of more than 80%. GR was evenly distributed on the scaffold as observed by energy spectrum analyzer and polarizing microscope. With increasing GR content, the mechanical strength of the scaffold was enhanced, and pore walls became thicker and smoother. BMSCs were inoculated on the different scaffolds. The cells distributed and extended well on Cs/Gel/HA/GR scaffolds. Compared to traditional methods in tissue-engineering, this technique displays important advantages in simulating natural cartilage with the ability to finely control the mechanical and chemical properties of the scaffold to support cell distribution and proliferation for tissue repair.
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Liu, Fwu-Hsing, Ruey-Tsung Lee, Wen-Hsueng Lin, and Yunn-Shiuan Liao. "Selective Laser Sintering of Bio-Metal Scaffold." Procedia CIRP 5 (2013): 83–87. http://dx.doi.org/10.1016/j.procir.2013.01.017.
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Kovach, Ildiko, Jens Rumschöttel, Stig E. Friberg, and Joachim Koetz. "Janus emulsion mediated porous scaffold bio-fabrication." Colloids and Surfaces B: Biointerfaces 145 (September 2016): 347–52. http://dx.doi.org/10.1016/j.colsurfb.2016.05.018.
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Chen, Xiao Feng, Ying Jun Wang, Chun Rong Yang, and Na Ru Zhao. "Biomimetic Fabrication and Characterization of BG/COL/HCA Scaffolds for Bone Tissue Engineering." Key Engineering Materials 336-338 (April 2007): 1574–76. http://dx.doi.org/10.4028/www.scientific.net/kem.336-338.1574.
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The bone tissue engineering scaffold was developed by compounded the type I collagen with the porous scaffold of the sol-gel derived bioactive glass (BG) in the system CaO-P2O5-SiO2. The resultant porous scaffold was treated in supersaturated calcification solution (SCS) to form the surface layer of hydroxyl-carbonate-apatite (HCA) since the type I collagen possessed good biocompatibility and bio-absorbability, and also, the ability of inducting calcium phosphates to precipitated inside and outside the collagen fibers where the collagen fibers acted as bio-macromolecules template for formation of bone-like inorganic minerals in nature bone such as: octo-calcium phosphate (OCP), tri-calcium phosphate (TCP) and hydroxyl-carbonate-apatite (HCA). On the other hand, the sol-gel derived bioactive glass also played an important role in formation of the above bio-minerals owing to its serial chemical reactions with the body fluid. The in vitro study in supersaturated calcification solution SCS indicated that the surface of the porous scaffold was able to induce formation of bone-like HCA crystals on the pore walls of the scaffold which possessed satisfactory cells biocompatibility.
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Ahsan, AMM, Ruinan Xie, and Bashir Khoda. "Heterogeneous topology design and voxel-based bio-printing." Rapid Prototyping Journal 24, no. 7 (October 8, 2018): 1142–54. http://dx.doi.org/10.1108/rpj-05-2017-0076.
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Purpose The purpose of this paper is to present a topology-based tissue scaffold design methodology to accurately represent the heterogeneous internal architecture of tissues/organs. Design/methodology/approach An image analysis technique is used that digitizes the topology information contained in medical images of tissues/organs. A weighted topology reconstruction algorithm is implemented to represent the heterogeneity with parametric functions. The parametric functions are then used to map the spatial material distribution following voxelization. The generated chronological information yields hierarchical tool-path points which are directly transferred to the three-dimensional (3D) bio-printer through a proposed generic platform called Application Program Interface (API). This seamless data corridor between design (virtual) and fabrication (physical) ensures the manufacturability of personalized heterogeneous porous scaffold structure without any CAD/STL file. Findings The proposed methodology is implemented to verify the effectiveness of the approach and the designed example structures are bio-fabricated with a deposition-based bio-additive manufacturing system. The designed and fabricated heterogeneous structures are evaluated which shows conforming porosity distribution compared to uniform method. Originality/value In bio-fabrication process, the generated bio-models with boundary representation (B-rep) or surface tessellation (mesh) do not capture the internal architectural information. This paper provides a design methodology for scaffold structure mimicking the native tissue/organ architecture and direct fabricating the structure without reconstructing the CAD model. Therefore, designing and direct bio-printing the heterogeneous topology of tissue scaffolds from medical images minimize the disparity between the internal architecture of target tissue and its scaffold.
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Gonzalez, Brittany A., Ariadna Herrera, Claudia Ponce, Marcos Gonzalez Perez, Chia-Pei Denise Hsu, Asad Mirza, Manuel Perez, and Sharan Ramaswamy. "Stem Cell-Secreted Allogeneic Elastin-Rich Matrix with Subsequent Decellularization for the Treatment of Critical Valve Diseases in the Young." Bioengineering 9, no. 10 (October 20, 2022): 587. http://dx.doi.org/10.3390/bioengineering9100587.
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Critical valve diseases in infants have a very poor prognosis for survival. Particularly challenging is for the valve replacement to support somatic growth. From a valve regenerative standpoint, bio-scaffolds have been extensively investigated recently. While bio-scaffold valves facilitate acute valve functionality, their xenogeneic properties eventually induce a hostile immune response. Our goal was to investigate if a bio-scaffold valve could be deposited with tissues derived from allogeneic stem cells, with a specific dynamic culture protocol to enhance the extracellular matrix (ECM) constituents, with subsequent stem cell removal. Porcine small intestinal submucosa (PSIS) tubular-shaped bio-scaffold valves were seeded with human bone marrow-derived mesenchymal stem cells (hBMMSCs), cultured statically for 8 days, and then exposed to oscillatory fluid-induced shear stresses for two weeks. The valves were then safely decellularized to remove the hBMMSCs while retaining their secreted ECM. This de novo ECM was found to include significantly higher (p < 0.05) levels of elastin compared to the ECM produced by the hBMMSCs under standard rotisserie culture. The elastin-rich valves consisted of ~8% elastin compared to the ~10% elastin composition of native heart valves. Allogeneic elastin promotes chemotaxis thereby accelerating regeneration and can support somatic growth by rapidly integrating with the host following implantation. As a proof-of-concept of accelerated regeneration, we found that valve interstitial cells (VICs) secreted significantly more (p < 0.05) collagen on the elastin-rich matrix compared to the raw PSIS bio-scaffold.
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Wang, Siyi, Rong Li, Yongxiang Xu, Dandan Xia, Yuan Zhu, Jungmin Yoon, Ranli Gu, et al. "Fabrication and Application of a 3D-Printed Poly-ε-Caprolactone Cage Scaffold for Bone Tissue Engineering." BioMed Research International 2020 (January 30, 2020): 1–12. http://dx.doi.org/10.1155/2020/2087475.
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Poly-ε-caprolactone (PCL) is a promising synthetic material in bone tissue engineering (BTE). Particularly, the introduction of rapid prototyping (RP) represents the possibility of manufacturing PCL scaffolds with customized appearances and structures. Bio-Oss is a natural bone mineral matrix with significant osteogenic effects; however, it has limitations in being constructed and maintained into specific shapes and sites. In this study, we used RP and fabricated a hollow-structured cage-shaped PCL scaffold loaded with Bio-Oss to form a hybrid scaffold for BTE. Moreover, we adopted NaOH surface treatment to improve PCL hydrophilicity and enhance cell adhesion. The results showed that the NaOH-treated hybrid scaffold could enhance the osteogenesis of human bone marrow-derived mesenchymal stem cells (hBMMSCs) both in vitro and in vivo. Altogether, we reveal a novel hybrid scaffold that not only possesses osteoinductive function to promote bone formation but can also be fabricated into specific forms. This scaffold design may have great application potential in bone tissue engineering.
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Leng, Chong Yan, Yong Shun Cui, Yin Li, Xiao Pei Wu, and Qing Hua Chen. "Investigation of Bio-Mimetic Synthesis SH/KGM/HAP Scaffold." Advanced Materials Research 763 (September 2013): 41–44. http://dx.doi.org/10.4028/www.scientific.net/amr.763.41.
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Sodium hyaluronate / konjac glucomannan (SH/KGM) porous scaffolds were prepared via blending sodium hyaluronate and konjac glucomannan. The ammonia was used as cross-linker in blending process. The SH/KGM scaffolds were soaked into calcium nitrate solution and then followed by immersing into simulated body fluid to get SH/KGM/HAP porous scaffolds. X-ray diffraction and fourier transform infrared spectroscopy (FTIR) were used to characterize the crystallization and chemical structure of SH/KGM and SH/KGM/HAP scaffold materials. The scanning electron microscope (SEM) was used to analysis the morphology of SH/KGM/HAP scaffold and BMSCs on surface of the scaffold. The results show that hydroxyl-apatite produced on the surface of the SH/KGM, which appears as spherical particles in the SH/KGM/HAP scaffold surface, and the SH/KGM/HAP porous scaffold possesses good biocompatibility with cell.
Dissertations / Theses on the topic "Bio-scaffold"
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Capranzano, Piera. "Sviluppo tecnologico ed implementazione clinica degli scaffold coronarici bio-riassorbibili." Doctoral thesis, Università di Catania, 2019. http://hdl.handle.net/10761/4131.
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La ricerca riportata nel presente elaborato è stata focalizzata sull'emergente tecnologia degli stent coronarici riassorbibili (BRS, bioresorbable scaffold), con l obiettivo di generare dati a medio e lungo termine che potessero contribuire a chiarire il comportamento di tale tecnologia nei diversi contesti clinici, a ottimizzarne l uso e a definire gli ostacoli alla sua applicazione ordinaria, per poter definire strategie mirate di sviluppo e miglioramento dell intera tecnologia dei BRS.
Per tale scopo, il presente progetto consta di diversi studi che possono essere raggruppati in:
- valutazione dei risultati clinici a medio termine associati all impianto del BRS Absorb;
- analisi di sottogruppo da registri monocentrici e multicentrici del BRS Absorb;
- registro con survey multicentrica mirata a valutare nella pratica clinica quotidiana i criteri di selezione dei pazienti da trattare con i BRS;
- documenti di consenso mirati a definire la tecnica di impianto ottimale e la selezione dei pazienti e delle lesioni potenzialmente candidate all'impianto del BRS Absorb;
- analisi mediante tecniche di imaging intravascolare mirate a valutare le caratteristiche dell interazione tra lo scaffold e la parete coronarica, che possono traslare in outcome clinici;
- valutazione dei risultati clinici a lungo termine associati all impianto del BRS Absorb.
Le caratteristiche e i risultati di tali studi sono stati riportati nel presente elaborato finale.
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Ju, Young Min. "A novel bio-stable 3D porous collagen scaffold for implantable biosensor." [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002354.
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PATRUCCO, ALESSIA. "KERATIN-BASED 3D SCAFFOLD DESIGN FOR BONE TISSUE ENGINEERING." Doctoral thesis, Università degli studi di Pavia, 2017. http://hdl.handle.net/11571/1203394.
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In questo lavoro di tesi è stato progettato e caratterizzato uno scaffold 3D di cheratina innovativo tramite un approccio bio-ingegneristico integrato che unisce anche lo stimolo bio-meccanico generato da un campo elettromagnetico pulsato (PEMF).
Lo scaffold è stato preparato mediante la fibrillazione di fibre di lana (cheratina) sfruttando i componenti istologici che le compongono (fibrille o cellule corticali), al fine di ottenere una struttura adatta alla rigenerazione ossea. E’ stato quindi progettato uno scaffold di cheratina (spugna di fibrille di lana) con micro e macro-porosità interconnesse di dimensione controllata, al fine di ospitare le cellule, favorendone l’adesione e guidando opportunamente la formazione di nuovo tessuto.
Crosslinks aggiuntivi impartiti alle catene cheratiniche hanno permesso di ottenere uno scaffold con eccellente stabilità in acqua nonostante l’elevato rigonfiamento, resilienza alla compressione e stabilità alla degradazione. La cheratina contiene sequenze di adesione cellulare che facilitano la crescita delle cellule. Infatti, cellule SAOS-2 coltivate sulle spugne di fibrille di lana in condizioni proliferative (PM) e osteoinduttive (OM), hanno mostrato rispettivamente una crescita e differenziamento ottimali. Il differenziamento, in termini di aumento della mineralizzazione e deposizione di proteine della matrice è stimolato dall’applicazione del PEMF. Lo stimolo bio-meccanico velocizza il processo di differenziamento in condizioni osteoinduttive, mostrando una perfetta sinergia tra gli stimoli biochimici e meccanici nell’accelerazione del processo differenziativo.
La valutazione della crescita di cellule staminali da midollo osseo su scaffold di cheratina 2D e 3D (film di fibrille di lana e idrogeli di cheratina) ha mostrato la loro efficacia nel supportare le cellule staminali; in particolare, i sistemi 3D, grazie al loro diverso tempo di degradazione, possono funzionare da cell-delivery system o da impalcatura a lungo termine.
L’elevato tempo di degradazione mostrato dalla spugna di fibrille di lana suggerisce che questo scaffold possa essere promettente come supporto a lungo termine per la formazione ossea in vivo.Novel keratin-based 3D scaffold for bone tissue engineering have been produced, characterized and tested, applying bio-mechanical stimuli generated by a pulsed electromagnetic field (PEMF). Controlled-size, interconnected porosity, tailored to match the natural bone tissue features, has been designed for cell guesting, proliferation and guided tissue formation, exploiting the natural histological structure of the wool fibers. Additional crosslinking of the keratin chains allowed obtaining excellent water stability and significant swelling due to the synergic contribution of hydrophilicity and porosity, associated to increased compression resilience and ageing resistance. Keratin contains cellular-binding motifs for cell attachment found in the native extra-cellular matrix which facilitate better growth, providing proliferation signals and minimising apoptotic cell death. Viability and consistent proliferation were observed for SAOS-2 human osteoblast cells cultured both in proliferative (PM) and osteogenic (OM) media, highlighted by PEMF application, especially in osteogenic conditions, with increased mineralization and higher ECM proteins deposition. PEMF stimulated an earlier differentiation in osteogenic conditions, showing a perfect synergy between biochemical and mechanical stimuli in acceleration of the differentiation process. Evaluation of the attachment and growth of human bone marrow mesenchymal cells on different 2D and 3D keratin-based scaffolds, made with wool fibril films, sponges and hydrogels, showed that keratin-based materials are an effective support for stem cell growth. In particular, 3D systems gave the best results and, thanks to the different ageing time, they can be suitable as cell delivery system or for long-term scaffolding. The longer degradation rate suggests that wool fibril sponges can be promising candidates for long-term support of bone formation in vivo.
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PECE, ROBERTA. "In vitro 3D co-culture of mesenchymal stromal cells and Hodgkin Lymphoma cells on Collagen Scaffolds." Doctoral thesis, Università degli studi di Genova, 2021. http://hdl.handle.net/11567/1047332.
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PURPOSE. Conventional 2D culture systems do not consider the importance of tissue architecture that is particularly relevant since tissue microenvironment deeply contribute to determine the outcome of anti-cancer treatments. In this study we aimed to set up and use an in vitro 3D models for Hodgkin lymphoma (HL) to evaluate the activity of specific ADAM10 inhibitors LT4 and MN8, alone or in combination with the anti-CD30 ADC brentuximab-vedotin (Bre-Ved).
METHODS. Three different 3D culture models were set up: mixed spheroids made of HL lymph node (LN) mesenchymal stromal cells (MSC) and Reed Sternberg/Hodgkin lymphoma cells (HL cells), LN-derived de-cellularized matrices and collagen sponges repopulated with both LN-MSC and HL cells.
RESULTS AND DISCUSSION. In these 3D systems LT4 and MN8 reduced the size of mixed spheroids and intracellular ATP content. In addition, sCD30 and TNFα shedding was limited by LT4 and MN8 that not only interfered with HL cell growth, but also enhanced the anti-lymphoma effect of Bre-Ved. This effect was evident at low and ineffective doses of Bre-Ved as well, indicating a possible synergistic scheme to potentiate ADC-based lymphoma therapy.
CONCLUSIONS. Both direct and combined anti-lymphoma effect of ADAM10 inhibitors with Bre-Ved can be studied in in vitro 3D model recapitulating features of LN microenvironment and leading to ADC effects improvement. For this reason, scaffolds may represent a new promising tool to reproduce LN architecture and useful for the study of pharmacological response.
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Borgio, Luca. "Design and development of a PVA composite scaffold for peripheral nerve regeneration." Doctoral thesis, Università degli studi di Padova, 2013. http://hdl.handle.net/11577/3423610.
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The peripheral nerve injuries represent 2.8% of the total annual trauma. More than 360.000 people at year in the U.S.A. and more than 300.000 in Europe undergo this type of lesion, which often can lead to a condition of permanent disability (Ciardelli and Chiono, 2005).
The main cause is represented by motor vehicle and sports accidents, nevertheless knives, glass, metal lacerations and bone fractures cover as much as 30% of the total cases. Even the same surgery, especially orthopedic on upper limb, it is often due to nerve injury, as they are traction maneuvers that are performed in childbirth, which cover a rate of 0.12% in all lesions (Ichiara et al , 2008).
Although surgery is a frequent medical practice in most of the cases, tissue engineering, based on knowledge and used of engineering materials, growth factors and cells (both staminal or somatic cells) is becoming more and more like a viable, and sometimes, only possibility of repair the peripheral nerve lesions (Geuna et al, 2007).
Based on these considerations it has been designed, built, developed and tested a composed tubular scaffold in polyvinyl alcohol (PVA) from chemical, physical and biological point of view. The PVA is a synthetic polymer, water-soluble, biocompatible, durable, inexpensive and hardly degradable. In order to facilitate a better kinetic of degradation of the material it has been chemically modified, by a oxidative reaction. This same reaction has been shown, moreover, to promote the release of neurotrophic factors, including TAT-CNTF, whose activity is known to be essential in the various stages of the peripheral nerves regeneration process.
The work course, from the material oxidation to the final product (through the freeze thawing technique) has developed a tubular polymer scaffold which is a patented industrial invention (No: VI2013A000019, class: A61K) deposited in “Camera di Commercio Industria, Artigianato e Agricoltura” of Vicenza, Italy.Le lesioni dei nervi periferici rappresentano il 2,8 % dei traumi totali annui. Più di 360.000 persone all’anno negli USA e più di 300.000 in Europa vanno incontro a questo genere di lesione, che spesso può portare ad una condizione di disabilità permanente (Ciardelli e Chiono, 2005). La causa principale è rappresentata dagli incidenti automobilistici e pratica sportiva; ciò nonostante lacerazioni da coltelli, vetri, metalli e fratture ossee ricoprono il 30 % della casistica. Anche la stessa chirurgia, specialmente quella ortopedica degli arti superiori, è spesso causa di lesione nervosa, come lo sono anche le manovre di trazione che vengono effettuate durante il parto, che ricoprono il 0,12 % della totalità delle lesioni (Ichiara et al, 2008). Sebbene nella maggior parte dei casi si ricorra alla chirurgia, l’ingegneria tissutale, basata su conoscenze di ingegneria dei materiali, fattori di crescita proteici e cellule (sia staminale che somatiche) si sta affermando sempre più come una valida, ed a volte, unica possibilità di riparazione delle lesioni nervose periferiche (Geuna et al,2007). Basandosi su queste considerazioni è stato ideato, costruito, sviluppato e testato, da un punto di vista chimico, fisico e biologico uno scaffold tubulare di polivinilalcol (PVA). Il PVA è un polimero sintetico, idrosolubile, biocompatibile, resistente, poco costoso e difficilmente degradabile. Al fine di favorire una migliore cinetica di degradazione, il materiale è stato modificato chimicamente, mediante una reazione di tipo ossidativo. Questa stessa reazione si è dimostrata, inoltre, idonea a favorire il rilascio di fattori neurotrofici, tra cui TAT-CNTF, la cui attività è fondamentale nelle varie tappe del processo rigenerativo dei nervi periferici. Il percorso di lavoro svolto, dalla ossidazione del materiale fino al prodotto finito (attraverso la tecnica di freese thawing) ha prodotto uno scaffold polimerico tubulare coperto da brevetto come invenzione industriale ((No: VI2013A000019, classe: A61K) depositato presso “Camera di Commercio Industria, Artigianato e Agricoltura” di Vicenza.
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Mondy, William Lafayette. "Data acquisition for modeling and visualization of vascular tree." [Tampa, Fla] : University of South Florida, 2009. http://purl.fcla.edu/usf/dc/et/SFE0003082.
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LANZILLOTTI, CARMEN. "Innovative drug delivery scaffolds as novel therapeutic strategy for bone tissue regeneration and treatment of osteosarcoma." Doctoral thesis, Università degli studi di Ferrara, 2022. http://hdl.handle.net/11392/2482878.
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Nuovi biomateriali impiantabili con sistema di rilascio di farmaci anti-tumorali stanno emergendo come terapia alternativa per la riparazione del tessuto osseo e il trattamento del cancro osseo, compreso l'osteosarcoma (OS). Biomateriali composti da idrossiapatite nanostrutturata, con stronzio (CD-HA2%Sr) funzionalizzati con i farmaci metotrexato (CD-HA2%Sr-MTX) e doxorubicina (CD-HA2%Sr-DOX), potrebbero rappresentare una nuova strategia terapeutica per la rigenerazione ossea e il trattamento dell’OS. L’OS è una neoplasia maligna dell’osso che colpisce pazienti pediatrici. Nonostante gli svantaggi, la linea terapeutica attuale consiste in chirurgia associata a chemioterapia con alte dosi di metotrexato e doxorubicina. Per la prima volta in questo studio, l’efficacia dei suddetti biomateriali è stata testata in vitro.
Gli obiettivi dello studio erano la valutazione delle (1)citocompatibilità e (2)osteoinduttività del biomateriale CD-HA2%Sr con l’impiego di cellule staminali mesenchimali da tessuto adiposo umano (hASCs) e (3)dell’effetto citotossico dei biomateriali funzionalizzati CD-HA2%Sr-MTX e CD-HA2%Sr-DOX su cellule tumorali di OS.
La citocompatibilità e osteoinduttività del biomateriale CD-HA2%Sr sono state analizzate nelle hASCs cresciute a contatto con i biomateriali fino a 14 giorni. La citocompatibilità è stata investigata tramite i saggi di vitalità cellulare Alamar Blue e Live/Dead, morfologia del citoscheletro e PCR Array per l’analisi dei geni coinvolti nella deposizione della matrice extracellulare. L’osteoinduttività è stata valutata tramite PCR Array per l’analisi dei geni coinvolti nel processo di osteogenesi, test ELISA specifico per l’osteocalcina (OCN) e l’analisi della deposizione di fosfati di calcio. L’attività citotossica dei biomateriali CD-HA2%Sr-MTX (45μg/mL) e CD-HA2%Sr-DOX (5μg/mL) è stata valutata utilizzando cellule umane di osteosarcoma ingegnerizzate con la proteina verde fluorescente (SAOS-eGFP) cresciute a contatto con i biomateriali fino a 7 giorni. L’effetto citotossico dei farmaci rilasciati è stato analizzato mediante la valutazione del numero di cellule e la misurazione dell’intensità della fluorescenza emessa dalle cellule cresciute a contatto con i biomateriali. Inoltre, la struttura dei biomateriale CD-HA2%Sr a contatto con hASCs e SAOS-eGFP, e CD-HA2%Sr-MTX e CD-HA2%Sr-DOX a contatto con SAOS-eGFP sono state analizzate con il microscopio elettronico a scansione (SEM) e confocale (CM).
La proliferazione delle hASCs a contatto con il biomateriale, l’architettura del citoscheletro ben organizzata e l’up-regolazione dei geni coinvolti nella deposizione della matrice extracellulare come integrine, caderine, collagene e metalloproteinasi hanno dimostrato che il biomateriale CD-HA2%Sr presenta citocompatibilità in vitro. L’aumentata espressione di OCN e mineralizzazione della matrice nelle colture di hASCs, insieme all’up-regolazione dei geni coinvolti nell’osteogenesi, hanno confermato l’osteoinduttività in vitro del biomateriale CD-HA2%Sr. D’altra parte, i risultati delle analisi Alamar Blue, SEM e CM, insieme alla misurazione della fluorescenza, hanno mostrato una diminuzione del numero di cellule SAOS-eGFP a contatto con i biomateriali funzionalizzati, CD-HA2%Sr-MTX e CD-HA2%Sr-DOX, rispetto a quello non funzionalizzato, CD-HA2%Sr, confermando la loro proprietà citotossica nei confronti delle cellule tumorali di OS.
I risultati in vitro hanno dimostrato le proprietà di citocompatibilità e osteoinduttività del biomateriale CD-HA2%Sr e che i biomateriali funzionalizzati, CD-HA2%Sr-MTX e CD-HA2%Sr-DOX, potrebbero rappresentare un buon sistema di rilascio dei farmaci metotrexato e doxorubicina per la cura dell’OS. Poiché questi biomateriali possiedono buone proprietà osteoinduttive, potrebbero rappresentare una nuova strategia terapeutica per la rigenerazione dell’osso.Introduction: New implantable drug-delivery scaffolds, which combine bone substitutes and anti-cancer molecules, are emerging as an alternative therapy for bone tissue repair and treatment of bone cancer, including osteosarcoma (OS). Innovative ceramic scaffolds composed of strontium-substituted nanostructured calcium-deficient hydroxyapatite (CD-HA 2%Sr) with drugs methotrexate (CD-HA 2%Sr-MTX) and doxorubicin (CD-HA 2%Sr-DOX) may represent an innovative delivery system for a novel therapeutic strategy, both for bone regeneration and OS treatment. OS is an aggressive malignant neoplasm of the bone, which mainly affects pediatric and young adult patients. Despite the several disadvantages, treatments consist of surgery and chemotherapy using high-dose methotrexate and doxorubicin drugs. In this study, for the first time, these innovative biomaterials were tested in vitro for their efficacy. Aims. The aims of this study were to evaluate on human adipose-derived mesenchymal stem cells (hASCs) (i) the cytocompatibility and (ii) the osteoinductivity of CD-HA 2%Sr scaffolds and (iii) to assess the cytotoxic effect of CD-HA 2%Sr-MTX and CD-HA 2%Sr-DOX drug-delivery scaffolds on OS cells proliferation. Material and methods. The cytocompatibility and osteoinductivity properties of CD-HA 2%Sr were assessed in hASCs grown on the scaffold, up to day 14. Cytocompatibility was investigated using Alamar Blue and Live/Dead assays, cytoskeleton morphology and human extracellular matrix PCR Array, whereas osteoinductivity was evaluated using human osteogenesis PCR Array, ELISA test specific for osteocalcin (OCN) and mineral matrix deposition analysis. The anti-OS cell proliferation activity of CD-HA 2%Sr-MTX (45μg/mL) and CD-HA 2%Sr-DOX (5μg/mL) was assessed employing the fluorescent engineered human osteosarcoma cell line SAOS-eGFP grown on biomaterials, up to day 7. The effects of released drugs were evaluated in terms of cell numbers and fluorescence intensity rate reductions in SAOS-eGFP cells grown on scaffolds. In addition, the structure of CD-HA 2%Sr scaffolds with both hASCs and SAOS-eGFP cells, and the structure of CD-HA 2%Sr-MTX and CD-HA 2%Sr-DOX scaffolds with SAOS-eGFP cells were analysed by scanning electron (SEM) and confocal microscopes (CM). Results. The increasing number of hASCs, the well-organised cytoskeleton architecture alongside the up-regulation of extracellular matrix genes including integrins, cadherins, collagens and MMPs suggested that CD-HA 2%Sr scaffold owns in vitro cytocompatibility. In hASC cultures, the increased OCN protein expression and matrix mineralization, alongside the up-regulation of genes involved in skeletal development, demonstrated CD-HA 2%Sr scaffold displays in vitro osteoinductivity. In addition, decreasing cell numbers, SEM and CM analyses, alongside fluorescence intensity measurement indicated that CD-HA 2%Sr-MTX and CD-HA 2%Sr-DOX scaffolds displayed a cell-killing effect on SAOS-eGFP cells compared to CD-HA 2%Sr, thus validating the in vitro anti-proliferative properties of these scaffolds. Conclusion. Overall, these in vitro results demonstrated the cytocompatibility and osteoinductivity properties of CD-HA 2%Sr scaffold. In addition, experimental data with functionalized CD-HA 2%Sr-MTX and CD-HA 2%Sr-DOX scaffolds indicate that these innovative biomaterials could represent a good delivery system for methotrexate and doxorubicin, which are anti-tumour drugs, for OS therapy. At the same time, since these innovative scaffolds, employed in vitro as with drug-delivery system, own a good osteoinductive properties too, they could be used as a novel therapeutic strategy for bone tissue regeneration.
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RIZZUTO, Luigi. "CARDIAC STEM CELLS AND BIOMATERIALS: INDUCTION OF MYOGENIC DIFFERENTIATION AND IMPLANTION OF BIOSYNTHETIC AND NATURAL MATRICES IN THE ADULT HEART." Doctoral thesis, Università degli Studi di Palermo, 2014. http://hdl.handle.net/10447/90847.
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Principal purpose of regenerative medicine for the cardiac tissue is to find the best way to inoculate stem cells in a specific myocardial area damage, improving their homing, integration and survival. To achieve this goal, the field of biomaterials is important to bypass this obstacles, modulating the environment for implanted cells and enhance CSC function in the heart. Biomaterials can mimic or include naturally occurring extracellular matrix and instruct stem cell function in different ways: promoting angiogenesis, enhancing stem cell engraftment and differentiation, and accelerating electromechanical integration of transplanted cells. The aim of this thesis was to assess whether the properties of three-dimensional polymer matrices in synthetic biomaterial such as polylactic acid and in natural origin as silk fibroin, if and how influence differentiative process of stem cells cardiac c-kit +. Another point considered was been the evaluation of expression of cardiac markers and sarcomeric proteins of cells isolated, inoculated in different types of scaffold and maintained in colture for 21gg in vitro and analyzed in RT-PCR and Real-time quantitative RT–PCR analysis. Also it was analyzed the immunogenicity of the scaffold when implanted in the dorsal subcutaneous region of nude mice, nude rats and SCID mice in order a possible use in vivo in the cardiac regeneration. These experiments showed a myocardial-like differentiation, in which the CSCs acquired a muscle-like shape, with the formation of initial intercalated disks, and a striated-like myofilament organization. In results shown below highlights evidence of an higher degree of differentiation using 3D scaffold for CSCs c-Kit+ that can be induced to differentiate definitely into cardiomyocytes thanks to three-dimensional culture of the scaffold, where is possible an environment similar to a cardiac niche in vivo.
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Yurie, Hirofumi. "The efficacy of a scaffold-free Bio 3D conduit developed from human fibroblasts on peripheral nerve regeneration in a rat sciatic nerve model." Kyoto University, 2019. http://hdl.handle.net/2433/242407.
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Chen, Zhichao. "Fabrication and research of 3D complex scaffolds for bone tissue engineering based on extrusion-deposition technique." Thesis, Loughborough University, 2017. https://dspace.lboro.ac.uk/2134/27522.
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Fabrication of scaffold is the key for bone tissue engineering, which is commonly regarded as the most potential route for repairing bone defects. Previously, porous ceramic scaffolds were fabricated through a variety of traditional methods, like moulding and casting, but most of them cannot produce customised tissue-engineered scaffolds. Therefore, 3D printing methods are gaining more attention and are currently being explored and developed to make scaffolds with acceptable biocompatibility. With the considerable development of bone tissue engineering, the bioactivity of scaffolds is becoming increasingly demanded, which leads to new methods and techniques to produce highly biomimetic bone scaffolds. In this study, a new fabrication process to optimise the structures of scaffolds was developed, and intensive researches were performed on the porous scaffolds to confirm their advantages in biological performance. Specifically, by combination of motor assisted extrusion deposition and gas-foaming (graphite as the porogen) technique, hierarchically porous scaffolds with improved microstructures, i.e. multi-scaled pores from nanometre to millimetre (nm-μm-mm), was successfully developed. In this thesis, the optimal content of porogen for scaffolds was studied in terms of compressive strength and in-rod porosities. The most concerned physicochemical properties of scaffolds were carefully examined and the results revealed that such scaffolds exhibit excellent physicochemical properties owing to hierarchically porous structures. Due to additional in-rod micropores and increased specific surface area, along with better hydrophilicity, hierarchically porous scaffolds exerted complete superiority in biological activity, including promoting cellular proliferation of osteoblasts, adhesion and spreading status, as well as the ability to induce cellular differentiation.
Book chapters on the topic "Bio-scaffold"
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Pais, A., J. L. Alves, and J. Belinha. "Optimized bone scaffold using a bio-inspired remodelling algorithm (BIRA) and additive manufacturing." In Advances and Current Trends in Biomechanics, 236–40. London: CRC Press, 2021. http://dx.doi.org/10.1201/9781003217152-52.
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Pennarossa, Georgia, Matteo Ghiringhelli, Fulvio Gandolfi, and Tiziana A. L. Brevini. "Tracheal In Vitro Reconstruction Using a Decellularized Bio-Scaffold in Combination with a Rotating Bioreactor." In Methods in Molecular Biology, 157–65. New York, NY: Springer US, 2021. http://dx.doi.org/10.1007/7651_2021_398.
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Izquierdo-Barba, Isabel. "Scaffold Designing." In Bio-Ceramics with Clinical Applications, 291–313. Chichester, UK: John Wiley & Sons, Ltd, 2014. http://dx.doi.org/10.1002/9781118406748.ch10.
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Bulgheroni, P., E. Bulgheroni, and M. Campagnolo. "Clinical Use of the Meniscal Scaffold." In Bio-orthopaedics, 389–97. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-54181-4_30.
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Dye, J. F. "From Secondary Intent to Accelerated Regenerative Healing: Emergence of the Bio-intelligent Scaffold Vasculogenic Strategy for Skin Reconstruction." In Vascularization for Tissue Engineering and Regenerative Medicine, 1–68. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-319-21056-8_20-1.
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Dye, J. F. "From Secondary Intent to Accelerated Regenerative Healing: Emergence of the Bio-intelligent Scaffold Vasculogenic Strategy for Skin Reconstruction." In Vascularization for Tissue Engineering and Regenerative Medicine, 205–71. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-319-54586-8_20.
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Batzli, Janet M., Michelle A. Harris, Dennis Lee, and Heidi A. Horn. "Feedback and Discourse as a Critical Skill for the Development of Experimentation Competencies." In Trends in Teaching Experimentation in the Life Sciences, 243–62. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-98592-9_12.
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AbstractDeveloping experimentation competencies is enhanced through scientific discourse and feedback. Students who are able to give and receive feedback through authentic scientific discourse are better able to reason about their science, identify questions, to value collaboration, construct knowledge, and to gain intellectual confidence as practicing scientists. Although the ACE-Bio Competencies were not the driver for our work, they were an important lens and affirmation of our curriculum where students learn to reason scientifically and do biological experimentation through scientific discourse and feedback. In this chapter we discuss the value of feedback, how we scaffold opportunities to practice giving and receiving feedback into a multi-week experimentation curriculum, and some practical implementation strategies with particular focus on the influence of a feedback-rich curriculum for students’ achievement of experimentation competencies. We provide examples, evidence, and instructional materials that support student learning through feedback and discourse. We articulate implications that would be relevant to junior faculty new to teaching experimentation as well as long-time practitioners. Finally, we outline affordances and persistent challenges to this type of teaching and learning, especially important when making decisions with limited resources.
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Xu, Zhanyan, and Paulo Jorge Bártolo. "Scaffold Design for Nerve Regeneration." In Virtual Prototyping & Bio Manufacturing in Medical Applications, 257–83. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-35880-8_11.
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Arai, Kenichi, and Koichi Nakayama. "Bio-3D Printed Organs as Drug Testing Tools." In Kenzan Method for Scaffold-Free Biofabrication, 149–64. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-58688-1_12.
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Ikeguchi, Ryosuke, Tomoki Aoyama, Hirofumi Yurie, Hisataka Takeuchi, Sadaki Mitsuzawa, Maki Ando, Souichi Ohta, et al. "Peripheral Nerve Regeneration Using Bio 3D Nerve Conduits." In Kenzan Method for Scaffold-Free Biofabrication, 127–37. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-58688-1_10.
Full textConference papers on the topic "Bio-scaffold"
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Foresti, Ruben, Stefano Rossi, and Stefano Selleri. "Bio composite materials: nano functionalization of 4D bio engineered scaffold." In 2019 IEEE International Conference on BioPhotonics (BioPhotonics). IEEE, 2019. http://dx.doi.org/10.1109/icb47650.2019.8945042.
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Huan, Zhijie, Weicheng Ma, Mingyang Xie, Hao Yang, and Xiangpeng Li. "Automated cell manipulation through 3D bio-scaffold via dielectrophoresis*." In 2018 13th World Congress on Intelligent Control and Automation (WCICA). IEEE, 2018. http://dx.doi.org/10.1109/wcica.2018.8630413.
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Boersma, Arnold, Fiora Rosati, and Gerard Roelfes. "DNA as scaffold for new bio-inspired catalytic systems." In XVth Symposium on Chemistry of Nucleic Acid Components. Prague: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, 2011. http://dx.doi.org/10.1135/css201112108.
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Habib, Ahasan, and Bashir Khoda. "Fiber Filled Hybrid Hydrogel for Bio-Manufacturing." In ASME 2020 15th International Manufacturing Science and Engineering Conference. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/msec2020-8294.
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Abstract The extrusion based three-dimensional (3D) bio-printing deposits cell-laden bio-ink with high spatial resolution and may offer living tissue regeneration. Due to the biocompatibility, less cytotoxicity and high water content, natural hydrogels are commonly considered as the bio-ink for scaffold fabrication. However, due to the low mechanical integrity, a large scale scaffold (> 10 layers) with intricate architecture is a challenge. In this paper, Cellulose-based nano-fiber and CMC are added with alginate material to improve the rheological behavior of the hybrid hydrogel. Shear-thinning behavior, shape fidelity, printability of the composition are investigated and evaluated for various compositions. Finally, both regular and freeform 3D scaffolds are fabricated with the proposed hybrid hydrogel to validate its printability and shape fidelity. The required properties of bio-ink are highly dependent upon the percentage composition and the solid content.
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Sharif, Hajar, Yaser Shanjani, Mihaela Vlasea, and Ehsan Toyserkani. "On the Bio-Mechanical Properties of a Dual-Porous Osteochondral Scaffold." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-68108.
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This work is concerned with the finite element modeling of a dual-porous scaffold including both fine and coarse pores. The layer with coarse pores is suitable for bone in vivo ingrowth and the finer pore layer is appropriate for in vitro cartilage culturing. Such scaffolds can be extensively used for repairing of osteochondral defects. The bio-mechanical properties of the proposed scaffold, including apparent stiffness and strain-based capability of the cell ingrowth, are identified using a 3D Finite Element Model. Moreover, to study the effect of the second layer on the strength of the whole scaffold, the stiffness of the dual and single-porous scaffolds was compared. The result of this study shows that the stiffness decreases by adding the second layer to a single-porous scaffold. Additionally, principal strain histograms of the single and the dual-porous scaffolds are compared to assess the effect of added layer on the capability for cell ingrowth stimulation of the whole structure. According to the results, the dual-porous scaffold provides more homogeneous distribution but a smaller amount of micro-strains which may cause different cell-growth behavior.
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Lin, Liulan, Jiafeng Zhang, and Minglun Fang. "Modelling the Bio-Scaffold for Repairing Symmetrical and Unsymmetrical Defective Skull." In 2008 2nd International Conference on Bioinformatics and Biomedical Engineering. IEEE, 2008. http://dx.doi.org/10.1109/icbbe.2008.222.
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Suzuki, Seiichi, Emiko Ito, and Tsutom Takahashi. "Fabrication of permeable separator as a nano-porous scaffold for bio-reactor." In 2012 5th Biomedical Engineering International Conference (BMEiCON). IEEE, 2012. http://dx.doi.org/10.1109/bmeicon.2012.6465427.
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Khoda, A. K. M. B., and Bahattin Koc. "Functionally Heterogeneous Porous Scaffold Design for Tissue Engineering." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-86927.
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Most of the current tissue scaffolds are mainly designed with homogeneous porosity which does not represent the spatial heterogeneity found in actual tissues. Therefore engineering a realistic tissue scaffolds with properly graded properties to facilitate the mimicry of the complex elegance of native tissues are critical for the successful tissue regeneration. In this work, novel bio-mimetic heterogeneous porous scaffolds have been modeled. First, the geometry of the scaffold is extracted along with its internal regional heterogeneity. Then the model has been discretized with planner slices suitable for layer based fabrication. An optimum filament deposition angle has been determined for each slice based on the contour geometry and the internal heterogeneity. The internal region has been discritized considering the homogeneity factor along the deposition direction. Finally, an area weight based approach has been used to generate the spatial porosity function that determines the filament deposition location for desired bio-mimetic porosity. The proposed methodology has been implemented and illustrative examples are provided. The effective porosity has been compared between the proposed design and the conventional homogeneous scaffolds. The result shows a significant error reduction towards achieving the bio-mimetic porosity in the scaffold design and provides better control over the desired porosity level. Moreover, sample designed structures have also been fabricated with a NC motion controlled micro-nozzle biomaterial deposition system.
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Fujita, H., and Y. Tanaka. "Investigation of scaffold materials for a bio-micropump using IPS cell derived cardiomyocytes." In TRANSDUCERS 2015 - 2015 18th International Solid-State Sensors, Actuators and Microsystems Conference. IEEE, 2015. http://dx.doi.org/10.1109/transducers.2015.7181381.
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Khoda, A. K. M. B., Ibrahim T. Ozbolat, and Bahattin Koc. "Modeling of Multifunctional Porous Tissue Scaffolds With Continuous Deposition Path Plan." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-86926.
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A novel modeling technique for porous tissue scaffolds with targeting the functionally gradient variational porosity with continuous material deposition planning has been proposed. To vary the porosity of the designed scaffold functionally, medial axis transformation is used. The medial axis of each layers of the scaffold is calculated and used as an internal feature. The medial axis is then used connected to the outer contour using an optimum matching. The desired pore size and hence the porosity have been achieved by discretizing the sub-regions along its peripheral direction based on the pore size while meeting the tissue scaffold design constraints. This would ensure the truly porous nature of the structure in every direction as well as controllable porosity with interconnected pores. Thus the desired controlled variational porosity along the scaffold architecture has been achieved with the combination of two geometrically oriented consecutive layers. A continuous, interconnected and optimized tool-path has been generated for successive layers for additive-manufacturing or solid free form fabrication process. The proposed methodology has been computationally implemented with illustrative examples. Furthermore, the designed example scaffolds with the desired pore size and porosity has been fabricated with an extrusion based bio-fabrication process.
Reports on the topic "Bio-scaffold"
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Altstein, Miriam, and Ronald J. Nachman. Rational Design of Insect Control Agent Prototypes Based on Pyrokinin/PBAN Neuropeptide Antagonists. United States Department of Agriculture, August 2013. http://dx.doi.org/10.32747/2013.7593398.bard.
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The general objective of this study was to develop rationally designed mimetic antagonists (and agonists) of the PK/PBAN Np class with enhanced bio-stability and bioavailability as prototypes for effective and environmentally friendly pest insect management agents. The PK/PBAN family is a multifunctional group of Nps that mediates key functions in insects (sex pheromone biosynthesis, cuticular melanization, myotropic activity, diapause and pupal development) and is, therefore, of high scientific and applied interest. The objectives of the current study were: (i) to identify an antagonist biophores (ii) to develop an arsenal of amphiphilic topically active PK/PBAN antagonists with an array of different time-release profiles based on the previously developed prototype analog; (iii) to develop rationally designed non-peptide SMLs based on the antagonist biophore determined in (i) and evaluate them in cloned receptor microplate binding assays and by pheromonotropic, melanotropic and pupariation in vivo assays. (iv) to clone PK/PBAN receptors (PK/PBAN-Rs) for further understanding of receptor-ligand interactions; (v) to develop microplate binding assays for screening the above SMLs. In the course of the granting period A series of amphiphilic PK/PBAN analogs based on a linear lead antagonist from the previous BARD grant was synthesized that incorporated a diverse array of hydrophobic groups (HR-Suc-A[dF]PRLa). Others were synthesized via the attachment of polyethylene glycol (PEG) polymers. A hydrophobic, biostablePK/PBAN/DH analog DH-2Abf-K prevented the onset of the protective state of diapause in H. zea pupae [EC50=7 pmol/larva] following injection into the preceding larval stage. It effectively induces the crop pest to commit a form of ‘ecological suicide’. Evaluation of a set of amphiphilic PK analogs with a diverse array of hydrophobic groups of the formula HR-Suc-FTPRLa led to the identification of analog T-63 (HR=Decyl) that increased the extent of diapause termination by a factor of 70% when applied topically to newly emerged pupae. Another biostablePK analog PK-Oic-1 featured anti-feedant and aphicidal properties that matched the potency of some commercial aphicides. Native PK showed no significant activity. The aphicidal effects were blocked by a new PEGylated PK antagonist analog PK-dF-PEG4, suggesting that the activity is mediated by a PK/PBAN receptor and therefore indicative of a novel and selective mode-of-action. Using a novel transPro mimetic motif (dihydroimidazole; ‘Jones’) developed in previous BARD-sponsored work, the first antagonist for the diapause hormone (DH), DH-Jo, was developed and shown to block over 50% of H. zea pupal diapause termination activity of native DH. This novel antagonist development strategy may be applicable to other invertebrate and vertebrate hormones that feature a transPro in the active core. The research identifies a critical component of the antagonist biophore for this PK/PBAN receptor subtype, i.e. a trans-oriented Pro. Additional work led to the molecular cloning and functional characterization of the DH receptor from H. zea, allowing for the discovery of three other DH antagonist analogs: Drosophila ETH, a β-AA analog, and a dF analog. The receptor experiments identified an agonist (DH-2Abf-dA) with a maximal response greater than native DH. ‘Deconvolution’ of a rationally-designed nonpeptide heterocyclic combinatorial library with a cyclic bis-guanidino (BG) scaffold led to discovery of several members that elicited activity in a pupariation acceleration assay, and one that also showed activity in an H. zea diapause termination assay, eliciting a maximal response of 90%. Molecular cloning and functional characterization of a CAP2b antidiuretic receptor from the kissing bug (R. prolixus) as well as the first CAP2b and PK receptors from a tick was also achieved. Notably, the PK/PBAN-like receptor from the cattle fever tick is unique among known PK/PBAN and CAP2b receptors in that it can interact with both ligand types, providing further evidence for an evolutionary relationship between these two NP families. In the course of the granting period we also managed to clone the PK/PBAN-R of H. peltigera, to express it and the S. littoralis-R Sf-9 cells and to evaluate their interaction with a variety of PK/PBAN ligands. In addition, three functional microplate assays in a HTS format have been developed: a cell-membrane competitive ligand binding assay; a Ca flux assay and a whole cell cAMP ELISA. The Ca flux assay has been used for receptor characterization due to its extremely high sensitivity. Computer homology studies were carried out to predict both receptor’s SAR and based on this analysis 8 mutants have been generated. The bioavailability of small linear antagonistic peptides has been evaluated and was found to be highly effective as sex pheromone biosynthesis inhibitors. The activity of 11 new amphiphilic analogs has also been evaluated. Unfortunately, due to a problem with the Heliothis moth colony we were unable to select those with pheromonotropic antagonistic activity and further check their bioavailability. Six peptides exhibited some melanotropic antagonistic activity but due to the low inhibitory effect the peptides were not further tested for bioavailability in S. littoralis larvae. Despite the fact that no new antagonistic peptides were discovered in the course of this granting period the results contribute to a better understanding of the interaction of the PK/PBAN family of Nps with their receptors, provided several HT assays for screening of libraries of various origin for presence of PK/PBAN-Ragonists and antagonists and provided important practical information for the further design of new, peptide-based insecticide prototypes aimed at the disruption of key neuroendocrine physiological functions in pest insects.