ABSTRACT
BACKGROUND: In recent years, the development of tissue engineering provides more choices for the repair of urethral injury.OBJECTIVE: To investigate the effect of bone marrow mesenchymal stem cells (BMSCs) combined with acellular dermal matrix in the repair of urethral injuries. METHODS: Passage 3 BMSCs from New Zealand white rabbits were inoculated on the acellular dermal matrix to construct tissue-engineered urethra grafts. Thirty-six New Zealand rabbits were randomized into three groups (n=12 per group). Experimental group was implanted with BMSCs-acellular dermal matrix complex at urethral injury. Control group was implanted with acellular dermal matrix material at urethral injury. Normal group had neither injury nor treatment. At postoperative 4, 8 and 12 weeks, the repaired urethral tissue was subjected to hematoxylin-eosin staining. At postoperative 12 weeks, immunohistochemical staining and urodynamic study were performed. RESULTS AND CONCLUSION: At postoperative 4 weeks, thin-layer epithelial regeneration was visible in the urethra defect area of the experimental group, and the continuity was better. The urethra mucosa of the control group was discontinuous. At postoperative 8-12 weeks, the urethral epithelial layer in the experimental group became thickened, exhibiting a good continuity with the normal urethral epithelium, thickened mucosa, and smooth and continuous urethral mucosa; the regenerated urethral mucosa of the control group exhibited good continuity, but less regenerated epithelial layers. At postoperative 12 weeks, immunohistochemical results showed the repaired urethra in the experimental group was positive for uroplakin IIIa, CK AE1/AE3, and α-smooth muscle actin. The maximum urethral pressure in the experimental group showed no significant difference before and after operation, while the postoperative pressure in the control group showed a significant increase (P < 0.05). Overall findings indicate that the combination of BMSCs and acellular dermal matrix has better efficacy than the acellular dermal matrix alone.