Magnesium Oxide Nanoparticle-Incorporated Electrospun Nanofiber Scaffolds for Bladder Repair

Functional bladder repair remains a significant clinical challenge due to the limitations of autologous tissue grafts, including donor site morbidity, limited availability, and poor integration, often leading to postoperative complications and surgical failure. To address this, we developed a bioactive electrospun membrane by incorporating magnesium oxide nanoparticles (MgONPs, diameter <44 nm) into a polycaprolactone (PCL)/gelatin nanofibrous scaffold. The fabricated membranes maintained excellent fiber continuity and uniformity, with the addition of MgO NPs significantly enhancing the ultimate tensile strength by over 50% and promoting a sustained release of Mg 2+ ions over 14 days. In vitro, the optimized nanostructured membrane (PGM-0.5, with 0.5% MgO) exhibited strong antibacterial activity, reducing the viability of E. coli and S. aureus by over 90% and 85%, respectively. Cell culture experiments demonstrated that PGM-0.5 enhanced the proliferation of urothelial cells and smooth muscle cells by approximately 40% compared to the control after 7 days. Crucially, these scaffolds modulated the immune response by reducing the expression of the M1 macrophage marker CD86 by ∼40% and increasing the M2 marker CD206 by ∼60%, indicating a shift toward a pro-healing anti-inflammatory phenotype. In vivo implantation in a rat bladder defect model confirmed the therapeutic efficacy, where the PGM-0.5 group achieved near-complete tissue regeneration, characterized by a well-organized, continuous urothelial layer, mature collagen deposition (with a collagen I/III ratio comparable to native tissue), and significant downregulation of the pro-inflammatory cytokine IL-1β. Therefore, this multifunctional nanofibrous electrospun patch, which integrates robust mechanical properties, antibacterial capability, and potent anti-inflammatory action, represents a promising nanotechnology-based strategy for effective bladder reconstruction, overcoming the key limitations of traditional approaches.