Integrated 'Shield-Spear' Biological Patch for Fibrosis-Free Bladder Reconstruction.

Bladder reconstruction without fibrosis remains a global challenge. Current bladder defect treatments primarily focus on repair at the level of vascularization, failing to balance healing and excessive collagen deposition, and neglecting the exacerbation of fibrosis due to neural dysregulation. In this study, an integrated 'shield-spear' patch composed of an anionic 'shield' hydrogel (HAD) and neuro-targeted 'spear' engineered extracellular vesicles (S100Aptamer-EVs) using Schiff base chemistry and Michael addition reactions is engineered.