Poly(l-lactic acid)/gelatin microfiber membrane loaded with mitomycin C promoting bladder defect repair by anti-fibrosis and antibacterial action

Abstract

When the bladder is affected by factors such as tumors, tuberculosis, or trauma, its normal structure and function can be severely damaged. At this point, bladder replacement or enlargement surgery may become necessary to restore its structure and improve the patient's quality of life. Traditional bladder reconstruction surgery, specifically ileum augmentation cystoplasty, involves a complex surgical process, along with relatively large operative wounds and possible intestinal obstruction complications. There is also an urgent need for suitable bladder replacement materials. Over the past decade, synthetic bladder scaffolds have emerged as alternatives; however, most fail to simultaneously address the issues of postoperative fibrosis and bacterial infection. To overcome these challenges, we developed an electrospun poly(L-lactic acid)/gelatin (PLLA/GEL) microfiber membrane loaded with mitomycin C (MMC). By optimizing the PLLA/GEL ratio (7 : 3), the membrane exhibited 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 a reduction in collagen III deposition through inhibition of the TGF-β/Smad2 pathway, as well as enhanced urothelium regeneration and promotion of angiogenesis. Notably, the membrane maintained cell viability for both urothelial cells and smooth muscle cells over 7 days, confirming its biocompatibility. These findings highlight the 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.