The Experts below are selected from a list of 16101 Experts worldwide ranked by ideXlab platform
Yu Luo - One of the best experts on this subject based on the ideXlab platform.
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Bioprosthetic heart valves with reduced immunogenic residuals using vacuum-assisted Decellularization treatment.
Biomedical materials (Bristol England), 2020Co-Authors: Yu LuoAbstract:Despite the good hemodynamic characteristics of bioprosthetic heart valves, it is inevitable that they will suffer from calcification and tissue deterioration. Decellularization has been utilized to reduce the immunogenicity and calcification of bioprosthetic heart valves. However, it can take several days or even weeks to obtain the decellularized tissues or organs. Therefore, time-frame should be taken into consideration during the Decellularization process. A detergent-enzymatic-method, combined with vacuum, has been proposed as a method of obtaining desirable decellularized heart valves. In this study, heart valves treated under vacuum and normal atmosphere are investigated via histological, biochemical and mechanical analysis. The results show that the Decellularization efficiency of heart valves treated under vacuum is enhanced, based on histological staining, DNA contents and α-Gal quantification. The Decellularization procedures decrease the contents of the extracellular matrix. However, the mechanical properties, including elastic modulus, fracture tensile strength and fracture strain, show no significant difference between the samples. In vitro cell cytotoxicity experiments indicate the feasibility of further in vivo experiments. Therefore, we conclude that vacuum-assisted Decellularization procedures can significantly enhance Decellularization efficiency by reducing the Decellularization time, without compromising the properties of the heart valves, which is also beneficial in terms of reducing clinical costs. To the best of our knowledge, vacuum is a novel parameter which can be designed into Decellularization procedures for heart valves.
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Bioprosthetic heart valves with reduced immunogenic residuals by vacuum-assisted Decellularization treatment
Biomedical Materials, 2020Co-Authors: Yu LuoAbstract:Despite the good hemodynamic characteristics of bioprosthetic heart valves, it is inevitable that they will suffer from calcification and tissue deterioration. Decellularization has been utilized to reduce the immunogenicity and calcification of bioprosthetic heart valves. However, it costs several days or even weeks to obtain the decellularized tissues or organs. Therefore, time-frame should be taken into consideration during the Decellularization process. Detergent-enzymatic-method combined with vacuum was performed to obtain desirable decellularized heart valves. In this study, heart valves treated under vacuum or normal atmosphere were investigated through histological, biochemical and mechanical analysis. Decellularization efficiency of heart valves treated under vacuum was enhanced according to the histological staining, DNA contents and α-Gal quantification results. The Decellularization procedures decreased the contents of extra-cellular matrix. However, the mechanical properties, including elastic modulus, fracture tensile strength and fracture strain, didn't show significant difference among the samples. In vitro cell cytotoxicity experiments indicated the feasibility for the further in vivo experiments. Therefore, vacuum-assisted Decellularization procedures can significantly enhance the Decellularization efficiency by reducing the Decellularization time without compromising the properties of heart valves, which can also be beneficial for lowering the costs in clinical. To the best of our knowledge, vacuum is one novel parameter which can be designed into Decellularization procedures of heart valves.
Amelia Seifalian - One of the best experts on this subject based on the ideXlab platform.
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development of a cost effective and simple protocol for Decellularization and preservation of human amniotic membrane as a soft tissue replacement and delivery system for bone marrow stromal cells
Advanced Healthcare Materials, 2015Co-Authors: Mazaher Gholipourmalekabadi, Masoud Mozafari, Mohammad Salehi, Amelia Seifalian, Mojgan Bandehpour, Hossein Ghanbarian, Aleksandra M Urbanska, Marzieh Sameni, Ali SamadikuchaksaraeiAbstract:The aim of this study is to develop a simple andcost-effective method for Decellularization and preservation of human amniotic membrane (HAM) as a soft tissue replacement and a delivery system for stem cells. The HAM is decellularized (D) using new chemical and mechanical techniques. The Decellularization scaffold is evaluated histologically and fully characterized. The cell adhesion and proliferation on the scaffold are also investigated and the biocompatibility of D tissues is evaluated in vivo. The histological studies reveal that the cells are successfully removed from the D tissue. The DNA extraction shows more than 95% cell removal (p = 0.001). The in vitro results indicate that the decellularisation process does not deteriorate the mechanical properties of the tissue, whereas it increases the in vitro biodegradation value (p 0.05). Immunohistochemistry staining indicates that all the tested components remain unchanged within the D tissues. The count of inflammatory cells show that the Decellularization process slightly increases the biocompatibility of the tissue after 7 days post-surgery. The results indicate that scaffold proves to be reproducible, rapid, and cost-effective, with a potential role for clinical application.
Richard A. Hopkins - One of the best experts on this subject based on the ideXlab platform.
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Species-specific effects of aortic valve Decellularization.
Acta biomaterialia, 2017Co-Authors: Mitchell C. Vedepo, Michael S. Detamore, Richard A. Hopkins, Rachael W. Quinn, Eric E. Buse, Todd D. Williams, Gabriel L. ConverseAbstract:Abstract Decellularized heart valves have great potential as a stand-alone valve replacement or as a scaffold for tissue engineering heart valves. Before decellularized valves can be widely used clinically, regulatory standards require pre-clinical testing in an animal model, often sheep. Numerous Decellularization protocols have been applied to both human and ovine valves; however, the ways in which a specific process may affect valves of these species differently have not been reported. In the current study, the comparative effects of Decellularization were evaluated for human and ovine aortic valves by measuring mechanical and biochemical properties. Cell removal was equally effective for both species. The initial cell density of the ovine valve leaflets (2036 ± 673 cells/mm2) was almost triple the cell density of human leaflets (760 ± 386 cells/mm2; p 0.10). This species-dependent difference in the effect of Decellularization was likely due to the higher initial cellularity in ovine valves, as well as a significant decrease in collagen crosslinking following the Decellularization of ovine leaflets that was not observed in the human leaflet. Decellularization also caused a significant decrease in the circumferential relaxation of ovine leaflets (p 0.30), which was credited to a greater reduction of glycosaminoglycans in the ovine tissue post-Decellularization. These results indicate that an identical Decellularization process can have differing species-specific effects on heart valves. Statement of Significance The decellularized heart valve offers potential as an improved heart valve substitute and as a scaffold for the tissue engineered heart valve; however, the consequences of processing must be fully characterized. To date, the effects of Decellularization on donor valves from different species have not been evaluated in such a way that permits direct comparison between species. In this manuscript, we report species-dependent variation in the biochemical and biomechanical properties of human and ovine aortic heart valve leaflets following Decellularization. This is of clinical significance, as current regulatory guidelines required pre-clinical use of the ovine model to evaluate candidate heart valve substitutes.
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Recellularization of decellularized heart valves: Progress toward the tissue-engineered heart valve:
Journal of tissue engineering, 2017Co-Authors: Mitchell C. Vedepo, Michael S. Detamore, Richard A. Hopkins, Gabriel L. ConverseAbstract:The tissue-engineered heart valve portends a new era in the field of valve replacement. Decellularized heart valves are of great interest as a scaffold for the tissue-engineered heart valve due to their naturally bioactive composition, clinical relevance as a stand-alone implant, and partial recellularization in vivo. However, a significant challenge remains in realizing the tissue-engineered heart valve: assuring consistent recellularization of the entire valve leaflets by phenotypically appropriate cells. Many creative strategies have pursued complete biological valve recellularization; however, identifying the optimal recellularization method, including in situ or in vitro recellularization and chemical and/or mechanical conditioning, has proven difficult. Furthermore, while many studies have focused on individual parameters for increasing valve interstitial recellularization, a general understanding of the interacting dynamics is likely necessary to achieve success. Therefore, the purpose of this revi...
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Recellularization of decellularized heart valves: Progress toward the tissue-engineered heart valve
SAGE Publishing, 2017Co-Authors: Mitchell C. Vedepo, Michael S. Detamore, Richard A. Hopkins, Gabriel L. ConverseAbstract:The tissue-engineered heart valve portends a new era in the field of valve replacement. Decellularized heart valves are of great interest as a scaffold for the tissue-engineered heart valve due to their naturally bioactive composition, clinical relevance as a stand-alone implant, and partial recellularization in vivo. However, a significant challenge remains in realizing the tissue-engineered heart valve: assuring consistent recellularization of the entire valve leaflets by phenotypically appropriate cells. Many creative strategies have pursued complete biological valve recellularization; however, identifying the optimal recellularization method, including in situ or in vitro recellularization and chemical and/or mechanical conditioning, has proven difficult. Furthermore, while many studies have focused on individual parameters for increasing valve interstitial recellularization, a general understanding of the interacting dynamics is likely necessary to achieve success. Therefore, the purpose of this review is to explore and compare the various processing strategies used for the Decellularization and subsequent recellularization of tissue-engineered heart valves
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Performance and Morphology of Decellularized Pulmonary Valves Implanted in Juvenile Sheep
The Annals of thoracic surgery, 2011Co-Authors: Rachael W. Quinn, Stephen L. Hilbert, Arthur A. Bert, Bill W. Drake, Julie A. Bustamante, Jason Fenton, Sara J. Moriarty, Stacy L. Neighbors, Gary K. Lofland, Richard A. HopkinsAbstract:Background Because of cryopreserved heart valve–mediated immune responses, decellularized allograft valves are an attractive option in children and young adults. The objective of this study was to investigate the performance and morphologic features of decellularized pulmonary valves implanted in the right ventricular outflow tract of juvenile sheep. Methods Right ventricular outflow tract reconstructions in juvenile sheep (160 ± 9 days) using cryopreserved pulmonary allografts (n = 6), porcine aortic root bioprostheses (n = 4), or detergent/enzyme–decellularized pulmonary allografts (n = 8) were performed. Valve performance (echocardiography) and morphologic features (gross, radiographic, and histologic examination) were evaluated 20 weeks after implantation. Results Decellularization reduced DNA in valve cusps by 99.3%. Bioprosthetic valves had the largest peak and mean gradients versus decellularized valves ( p = 0.03; p p = 0.01; p = 0.001), which were similar ( p = 0.45; p = 0.40). Regurgitation was minimal and similar for all groups ( p = 0.16). No cusp calcification was observed in any valve type. Arterial wall calcification was present in cryopreserved and bioprosthetic grafts but not in decellularized valves. No autologous recellularization or inflammation occurred in bioprostheses, whereas cellularity progressively decreased in cryopreserved grafts. Autologous recellularization was present in decellularized arterial walls and variably extending into the cusps. Conclusions Cryopreserved and decellularized graft hemodynamic performance was comparable. Autologous recellularization of the decellularized pulmonary arterial wall was consistently observed, with variable cusp recellularization. As demonstrated in this study, decellularized allograft valves have the potential for autologous recellularization.
Xianfeng Lin - One of the best experts on this subject based on the ideXlab platform.
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Decellularized cartilage as a prospective scaffold for cartilage repair.
Materials science & engineering. C Materials for biological applications, 2019Co-Authors: Chen Xia, Sheng Mei, Lin Zheng, Chen Fang, Yiling Shi, Yongming Jin, Xianfeng LinAbstract:Articular cartilage lacks self-healing capacity, and there is no effective therapy facilitating cartilage repair. Osteoarthritis (OA) due to cartilage defects represents large and increasing healthcare burdens worldwide. Nowadays, the generation of scaffolds to preserve bioactive factors and the biophysical environment has received increasing attention. Furthermore, improved Decellularization technology has provided novel insights into OA treatment. This review provides a comparative account of different cartilage defect therapies. Furthermore, some recent effective Decellularization protocols have been discussed. In particular, this review focuses on the Decellularization ratio of each protocol. Moreover, these protocols were compared particularly on the basis of immunogenicity and mechanical functionality. Further, various recellularization methods have been enlisted and the reparative capacity of decellularized cartilage scaffolds is evaluated herein. The advantages and limitations of different recellularization processes have been described herein. This provides a basis for the generation of decellularized cartilage scaffolds, thereby potentially promoting the possibility of Decellularization as a clinical therapeutic target.
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Decellularized tendon as a prospective scaffold for tendon repair
Materials Science and Engineering: C, 2017Co-Authors: Shengyu Wang, Yiyun Wang, Liyang Song, Jiaxin Chen, Chen Yunbin, Shunwu Fan, Xianfeng LinAbstract:Tendon injuries impose significant clinical burdens on healthcare systems worldwide. At present, no therapeutic methods can cure tendon injuries in an ideal manner. With the development and improvement of Decellularization technology, tendon extracellular matrix (ECM) can develop into novel scaffolds with potential for repairing injured tendons. Proper agents and Decellularization protocols were developed to obtain tendon ECMs, and the method used to recellularize the tendon ECM was explored to create bio-functional neo-tendons for transplants. Further, preliminary testing was done to evaluate the reparative capacity of decellularized tendon scaffolds (DTSs). Here, we assess developments in tendon Decellularization and recellularization processes, as well as the possibility for advancing DTSs into clinical applications based on recent findings.
Fabio Gava Aoki - One of the best experts on this subject based on the ideXlab platform.
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de epithelialization of porcine tracheal allografts as an approach for tracheal tissue engineering
Scientific Reports, 2019Co-Authors: Fabio Gava Aoki, Ratna Varma, Alba E Marinaraujo, Hankyu Lee, John P Soleas, Kayla Soon, David A RomeroAbstract:Replacement of large tracheal defects remains an unmet clinical need. While recellularization of acellular tracheal grafts appeared to be a viable pathway, evidence from the clinic suggests otherwise. In hindsight, complete removal of chondrocytes and repopulation of the tracheal chondroid matrix to achieve functional tracheal cartilage may have been unrealistic. In contrast, the concept of a hybrid graft whereby the epithelium is removed and the immune-privileged cartilage is preserved is a radically different path with initial reports indicating potential clinical success. Here, we present a novel approach using a double-chamber bioreactor to de-epithelialize tracheal grafts and subsequently repopulate the grafts with exogenous cells. A 3 h treatment with sodium dodecyl sulfate perfused through the inner chamber efficiently removes the majority of the tracheal epithelium while the outer chamber, perfused with growth media, keeps most (68.6 ± 7.3%) of the chondrocyte population viable. De-epithelialized grafts support human bronchial epithelial cell (BEAS-2B) attachment, viability and growth over 7 days. While not without limitations, our approach suggests value in the ultimate use of a chimeric allograft with intact donor cartilage re-epithelialized with recipient-derived epithelium. By adopting a brief and partial Decellularization approach, specifically removing the epithelium, we avoid the need for cartilage regeneration.
