Experimental study on mechanical properties of decellularized porcine aortic valve and effects of precoating methods of biological scaffold on histocompatibility

Objective To observe the mechanical properties of decellularized porcine aortic valve, and to explore the effects of precoating methods of biological scaffold on histocompatibility.Methods Fresh porcine aortic valves were decellularized using trypsin,TritonX-100 and nuclease.Treated valves were evaluated by light microscopy,scanning electron microscopy(SEM)and mechanical test.Three groups of scaffold were precoated with phosphate buffered saline(PBS),poly-L-lysine(PLL)and fetal bovine serum (FBS)respectively.Myofibroblasts were seeded onto each scaffold.Light and electron microscopic observation was performed and MTT test was used to examine efficiency of cell attachment.Results HE stain and SEM showed that cells were almost absent in the treated leaflet.The wave-like collagen together with the whole three-dimensional structure was maintained.Compared with normal valves,the Max-load, Max-stress and elastic modulus decreased while the Max-strain increased(P0.05).The result of MTT test showed more cells were attached on the valves treated with FBS compared to the other two groups. Histological investigations also confirm that the high degree of cell attachment on the valves precoated with FBS(F=129.26,P=0.000).Conclusions Enzyme combined with detergent and nucleases can remove ceils from porcine aortic valves.Meanwhile the mechanical properties of these valves may be altered. Precoating porcine aortic valve with FBS is an effective method to improve cell attachment,growth and increasing.