Poly (L-lactic acid)/Gelatin microfiber membrane loaded with Mitomycin C promoting bladder defect repair by anti-fibrosis and anti-bacteria

When the bladder is affected by factors such as tumors, tuberculosis, and trauma, its normal structure and function will be damaged inescapably. At this point, bladder replacement or enlargement surgery becomes necessary to restore its structure and improve the patient's quality of life. Traditional bladder reconstruction surgery, specifically ileum augmentation cystoplasty, has a complex surgical process, along with relatively large operative wounds and intestinal obstruction complications. There is an urgent need for bladder replacement material. Over the past decade, synthetic bladder scaffolds have emerged as alternatives; however, most fail to simultaneously address postoperative fibrosis and bacterial infection. To overcome these challenges, we developed an electrospinning poly (L-lactic acid)/gelatin (PLLA/GEL) microfiber membrane loaded with mitomycin C (MMC). By optimizing the PLLA/GEL ratio (7:3), the membrane had both good rigidity and excellent elasticity. The MMC-loaded fibers demonstrated sustained drug release, effectively inhibiting E. coli and S. aureus in vitro. In rat partial cystectomy models, the PLLA/GEL/MMC group showed reducing collagen III deposition through TGF-β/Smad2 pathway inhibition, enhancing urothelium regeneration and promoting angiogenesis. Notably, the membrane-maintained cell viability for both urothelial cells and smooth muscle cells over 7 days, confirming biocompatibility. These findings highlight a promising potential of the PLLA/GEL/MMC microfiber membrane not only as a material for bladder tissue engineering but also as a tool for therapeutic intervention that addresses multiple facets of bladder healing and regeneration.