[Effect of decellular treatment on the framework of extracellular matrix in bovine jugular vein conduit].

ABSTRACT

OBJECTIVE: To investigate the effect of decellular treatment on the framework constituents of extracellular matrix and tissue stability in bovine jugular vein conduit (BJVC), and to provide an evidence for tissue engineering of vascular prosthesis. METHODS: Bovine jugular veins were obtained fresh from a local slaughterhouse and were stored in chilled PBS. In the laboratory, any fat and loose connective tissue on the outer surface of the vessel was trimmed. BJVCs were decellularized by a 3-step extraction method as detergent Triton X-100 (0.5%), Trypsin (0.025%) EDTA (0.02%), and DNase I(30kU/L) RNaseA(0.3g/L). Histological and transmission electron microscopy (TEM) techniques were used to study the framework constituents of extracellular matrix of treated the examples, and fresh tissues were used as controls. Tissue contents of hydroxyproline(alkaline hydrolysis method) and elastin (Fastin Elastin Assay) were assayed respectively in the fresh and decellularized groups (n=10). The vascular wall heat shrinking temperature and mechanical strength were measured to evaluate the tissue stability (n=10). RESULTS: Histochemical and TEM analysis of BJVCs treated with decellularization proved a complete removal of nuclear and other cell components. Tissue collagen was well kept,but elastin was partly lessened. Tissue content of hydroxyproline increased comparatively [(25.73+/-2.97)mg/g vs. (29.25+/-2.99)mg/g, P<0.05] and the elastin content obviously decreased [(159.71+/-21.06)mg/g vs. (134.91+/-35.40)mg/g, P<0.05] in the decellular treatment group compared with the control group. The heat shrinking temperature and tensile stress of decelluarized tissue were lower than those of the fresh tissue[(72.50+/-0.53) degrees C vs. (69.75+/-0.54)degrees C ,P<0.05], [(5.19+/-0.65)MPa vs. (3.13+/-0.94)MPa, P<0.05]. CONCLUSION: The basic framework of extracellular matrix in the decellularized BJVC is partly damaged and tissue stability is reduced. Decellularized BJVC should be further crosslinked before being used as a tissue engineering scaffold for clinical pulmonary artery graft.