Effect of decellularization on tissue composition and immunogenicity of porcine and human aortic valves

Objective To study the changes of tissue composition and immunogenicity of porcine and human aortic valves after decellularization.Methods Three cryopreserved human aortic valves and 4 porcine valves were decellularized with trypsin,and the leaflet tissue was homogenized for SDS-PAGE protein electrophoresis and U-937 migration assay.Results Trypsin effectively removed the cells from the valve.SDS-PAGE demonstrated an obvious difference in the tissue composition between porcine and human valves.Although decellularization significantly diminished the differences between the valves,decellularized procine aortic valve stilled contained more protein components(between 26 000 and 43 000) than human valve.U-937 migration assay showed an obvious decrease of cell migration in the valves by decellularization(from 832.7×103 to 152.4±31.1×103 for porcine valves,P0.01,and from 644.9×103 to 91.2×103 for the human valves,P0.01).Decellularized porcine valves induced a significantly greater cell migration than decellularized human valves(P0.05).Conclusion Decellularization with trypsin can effectively decrease the immunogenicity of human or porcine heart valve,but can not completely eliminate the antigen,and decellularized porcine valve still retain strong immunogenicity.