Polymer Brush‐Based Asymmetric Porous Patch with Excellent Anti‐Bacterial and Anti‐Contamination Properties Enables Infectious Abdominal Wall Defect Repair

Well-integration of multiple bioactive components into a biological patch without damaging its cellular matrix structure is crucial for infectious abdominal wall defect repair but remains challenging. Herein, a novel asymmetric biological composite patch (bPVA/SIS⁺-NP) is developed by in situ introducing zwitterionic polyvinyl alcohol molecular brush (bPVA) hydrogel to a cationic small intestinal submucosal decellularized matrix (SIS⁺) via a self-induced phase separation based united strategy. Due to its high hydrogen bonding crosslinking and strong mechanical interlocking with SIS⁺-NP layer, bPVA layer can maintain stable anti-contamination and the corresponding anti-adhesion properties in the contaminated environment. On the basis of preserving an original extracellular matrix skeleton, SIS⁺-NP layer can show strong contact anti-bacterial ability at the acute stage of repair together with the prolonged drug release during the healing stage of repair. Furthermore, the in situ combination of bPVA and SIS⁺-NP layers can lead to a high and stable burst pressure tolerance. By comprehensive control of bacteria and their necrotic products, bPVA/SIS⁺-NP patch can achieve anti-infection, anti-adhesion, and pro-healing properties in the infectious abdominal wall defect on rats. Therefore, the bPVA/SIS⁺-NP patch opens a new avenue for bio-friendly construction of multifunctional biological patches to address the stringent requirements of infectious abdominal wall defect repair.