Abstract: Objective To observe the role of subcutaneous pretreated bladder acellular matrix graft-silk fibroin （BAMG-SF） for bladder reconstruction in a rat bladder augmentation model. Methods After BAMG-SF was implanted subcutaneously for 1 day, 3 days, 7 days and 14 days in 4 four-week-old female Sprague Dawley rat, the scaffold and tissues around it were harvested for histology evaluation. Set 4 groups （n=3）： simple BAMG-SF （control group）, BAMG-SF 3 days subcutaneous precondition （3 days group）, BAMG-SF 7 days subcutaneous precondition （7 days group） and the autologous tissue around BAMG-SF 7 days subcutaneous precondition （autologous group）. All groups were used to reconstruct bladder in a rat bladder augmentation model, the bladder was harvested for histology and immunology evaluation 4 weeks later. Results After BAMG-SF implanted subcutaneously for 7 days, a large number of cells were observed in BAMG-SF. After BAMG-SF implanted subcutaneously for 14 days, BAMG-SF was covered by autologous tissue. The reconstruction of vascular and muscle in 3 days group were better than other groups, only the autologous group had no stone found. Conclusion BAMG- SF can be used for bladder repair, 3-day group has the best effect on bladder reconstruction and autologous group can avoid stone formation effectively.

Key words: Bladder acellular matrix graft, Silk fibroin, Subcutaneous pretreatment, Bladder augmentation model