To evaluate the therapeutic effects of biological grafts derived from different tissue, to provide reference information for the clinical choice of biological grafts.

Healthy SD rats were randomly divided into 5 groups (n=10). Bilateral partial thickness defect in abdominal wall of rats were created and repaired with either basement membrane (BM)/small intestine submucosa (SIS) composite extracellular matrix (ECM) graft, SIS, dermis or pericardium, while untreated defects were served as control. Animals were sacrificed at 2, 4, 8 and 16 weeks after surgery, the incidence of seroma, shrinkage in repair area and degradation of implants were recorded. The repaired abdominal walls were harvested for histological evaluation to observe cell ingrowth, neovascularization, and fibrous encapsulation.

No seroma formation was observed in BM/SIS composite ECM graft repaired samples, and the samples replaced with dense and well-organized collagen fibers with mainly initial dimensions at 4 weeks post-surgery, degraded at 8 weeks post-surgery. There still presents massive inflammatory cells infiltration in SIS repaired area at 4 weeks post-surgery. At 8 weeks post-surgery, seroma incidence in SIS repaired samples was 65% and SIS was degraded. SIS had reconstructed tissue defects with a notable shrinkage rate of -52.0%±9.8%. 50% of dermis repaired area was infiltrated by cells and fully degraded. Fibrous encapsulation was formed in other dermis repaired area and cells were only infiltrated in the interface area. Significant enlargement compared with original implant area and no obvious degradation were observed. During the experimental period, scarcely any cells infiltrated the scaffold of pericardium with a shrinkage rate of -29.5%±14.0% at 16 weeks post-surgery. No degradation was observed and fibrous encapsulations were formed in pericardium repaired samples.

BM composite graft has shown a better tissue regeneration compared with SIS, dermis and pericardium.