Degradation behaviors of biological grafts derived from different tissue were investigated by taking the degradation experiments in vivo and in vitro respectively.

In vitro, solutions of collagenase type I was used to mimic the degradation of biological grafts including the basement membrane (BM)/small intestine submucosa (SIS) composite extracellular matrix (ECM) graft, SIS and chemical cross-linking pericardium (PC). Wistar mice were used as abdominal degradation model in vivo to evaluate the degradation process and therapeutic effect of biological grafts derived from different tissue.

Results showed that the non-crosslinked BM/SIS and SIS matrix were totally degraded in 120 h for collagenase I in vitro corresponding the degradation rate of the PC patch was only 4.3%±1.9%. BM/SIS matrix was totally degraded in 2 months in vivo, the samples replaced with dense and well-organized collagen fibers. At 2 months post-surgery, SIS also was degraded. While SIS had reconstructed tissue defects with novel-organized collagen fibers. During the experimental period, no degradation was observed and fibrous encapsulations were formed in pericardium repaired samples at 12 months post-surgery.

Results demonstrated the processes of degradation and tissue repair were matched well of BM composite graft with a better degradation rate and tissue regeneration compared with SIS and pericardium.