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Query: UNIPROT:P00790 (PGA)
 2,475 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Several surgical disciplines apply cartilage grafts for reconstructive purposes and have to overcome the scarcity of donor sites for this unique tissue. Employing the techniques of tissue engineering, cartilage might be generated in reasonable amounts for clinical purposes. Application of growth factors together with biochemical and biomechanical scaffold properties influence the process of ex vivo transplant production. The aims of this study are: 1) to investigate the influence of IGF-1 and TGFbeta-2 on tissue engineered human septal cartilage in vitro and in vivo after transplantation in nude mice; 2) to analyse the effect of the polydioxanone (PDS) content of the biodegradable Ethisorb E210 scaffold on the properties of the implanted constructs. Cells were three-dimensionally cultured on biodegradable Ethisorb E210 (PGA-PLA-copolymer fleeces with polydioxanone (PDS) adhesions), or on E210 scaffolds with a reduced polydioxanone content. Wet weight (ww), GAG-, and hydroxyprolin-content, as well as the cellularity of the neocartilage constructs were quantitatively evaluated. Additionally, the in vivo resorption of the two types of cell carriers was monitored. Addition of growth factors clearly increased the wet weight of the in vitro cultured constructs before transplantation. After transplantation, high PDS content improved the in vivo stability and macroscopic morphometric appearance of the tissue engineered specimens and led to enhanced deposition of glycosaminoglycans in transplanted constructs. Hydroxyproline content of the implants was not affected by either growth factors or PDS content. These data suggest a role for IGF-1 and TGFbeta-2 in preparative in vitro culture of chondrocytes before implantation, while PDS content of the scaffold is important for in vivo properties of the implanted material.
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PMID:Growth factors and scaffold composition influence properties of tissue engineered human septal cartilage implants in a murine model. 1914 66

Human articular cartilage is an avascular structure, which, when injured, poses significant hurdles to repair strategies. Not only does the defect need to be repopulated with cells, but preferentially with hyaline-like cartilage.SUCCESSFUL TISSUE ENGINEERING RELIES ON FOUR SPECIFIC CRITERIA: cells, growth factors, scaffolds, and the mechanical environment. The cell population utilized may originate from cartilage itself (chondrocytes) or from growth factors that direct the development of mesenchymal stem cells toward a chondrogenic phenotype. These stem cells may originate from various mesenchymal tissues including bone marrow, synovium, adipose tissue, skeletal muscle, and periosteum. Another unique population of multipotent cells arises from Wharton's jelly in human umbilical cords. A number of growth factors have been associated with chondrogenic differentiation of stem cells and the maintenance of the chondrogenic phenotype by chondrocytes in vitro, including TGFbeta; BMP-2, 4 and 7; IGF-1; and GDF-5.Scaffolds chosen for effective tissue engineering with respect to cartilage repair can be protein based (collagen, fibrin, and gelatin), carbohydrate based (hyaluronan, agarose, alginate, PLLA/PGA, and chitosan), or formed by hydrogels. Mechanical compression, fluid-induced shear stress, and hydrostatic pressure are aspects of mechanical loading found in within the human knee joint, both during gait and at rest. Utilizing these factors may assist in stimulating the development of more robust cells for implantation.Effective tissue engineering has the potential to improve the quality of life of millions of patients and delay future medical costs related to joint arthroplasty and associated procedures.
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PMID:Tissue engineering and cartilage. 1927 12