Various methods of preparing acellular tissue-engineered xenogeneic valve stents

Background: Excellent low-antigenicity xenogeneic biological valve scaffold is the premise of constructing tissue-engineered valve by using which kind of acellular methods. Objective: To explore the optimal preparation method of making tissue engineered heart valves by measuring efficiency of different acellular methods and ability to preserve the matrix. Design, time and setting: The prospective randomly controlled study was performed at the Central Laboratory of Taian Central Hospital from January 2007 to June 2008. Materials: Sixteen specimens of porcine aortic valves were randomly divided into control, NaCl-sodium-dodecyl-sulfate (SDS), trypsin and triton-X100 groups. Methods: Specimens in the control group were left intact. Three test groups were decellularized with NaCl, trypsin and Triton-X100 respectively. Main outcome measures: The gross structure, optical and electron microscope ultrastructure of the decelluarated porcine heart valve matrix was compared. The expression of vascular endothelial cell major histocompatibility complex (MHC)- I antigen was detected by immunohistochemical method. Results: Treatment with NaCL-SDS achieved only incomplete decellularization. The main components of extracellular matrix were reserved completely, but the fibrous components became unclear and swelling. Treatment with trypsin removed cells completely, but caused serious structural alterations, with the presence of swollen collagen fiber, crude edge, widen and irregular fiber interspace. Treatment with Triton-X100 achieved both complete decelluarization and preservation of the matrix structure. Valves following treatment of NaCl-SDS, trypsin and Triton-X100 had certain immunogenicity. However, the immunogenicity of valves following treatment of trypsin and Triton-X100 was significantly lower compared with the treatment of NaCL-SDS. Conclusion: The decellularization method by Triton-X100 is effective and complete. The Triton-X100 method does not change matrix structure and has low immunogenicity.