[Decellularized human tissue engineering aortic valves conduit].

ABSTRACT

OBJECTIVE: To explore the suitable method to create a decellularized human tissue engineering homograft aortic valves conduit and to study its biologic, immol/Lunological, and biomechanical properties. METHODS: Human homograft aortic valves conduits donated by healthy adult males undergoing brain death preserved in liquid nitrogen were treated with pH 8.0 hypotonic Tris buffer for 12 hours; then pH 8.0 isotonic buffer with 0.5% DOA, 1% DOA or 1% Triton for 12 hours-24 h; l and then pH 7.6 isotonic buffer with DNAase 200 micro g/ml, RNAase 20 micro g/ml for 2 hours. the histology, HLA-DR antigen, water content, thinkness, denaturation temperature, DNA content, Collagen Contents, stress-strain, destroying stress were examined. RESULTS: In comparison with the standard cryopreserved human homograft aortic valves conduit, the valves, wall and muscle of the homograft aorta treated by 1% DOA for 24 hours were decellularized completely, and the 3-dimensional network structure of elastic fibers and collagenous fibers remained intact. Immol/Lunohistochemistry showed a remarkable decrease of expression of tissue genome DNA contents, a decrease by 91.14% in the valves, and by 91.53% in the wall, and a remarkable decrease of the expression of HLA-DR antigens. However, the water content in the decellular aortic wall was increased significantly (75.4 +/- 1.8 vs 82.0 +/- 0.7, P < 0.05). No significant differences were found in the denaturation temperature, stress-strain, destroying stress parameter, and tissue extension ratio in the decellular human homograft aortic valves conduits. CONCLUSION: The decellularization method by isotonic buffer with 1% DOA-DNAase is effective. The decellularized human homograft aortic valves conduits are unaltered in biologic, biomechanical, and physical properties with lowered immol/Lunogenicity, It can be used as an ideal valve for patients or as a homograft stent for developing tissue engineering valve by host recellularization.