Bio-inspired multiple composite film with anisotropic surface wettability and adhesion for tissue repair

The ideal patch for tissue repair can induce host cells to migrate directionally to defected area and proliferate rapidly to form healthy granulation, while avoiding the adhesion and abrasion with adjacent tissues. However, existing patches hardly achieve this goal because of the contradictory processes during tissue repair, the single property of biomaterials as well as the absence of effective surface microstructures. Herein, we present a bio-inspired composite patch film that simultaneously integrate opposite properties of adhesion and anti-adhesion. Based on a double-layered inverse opal scaffold, the liquid paraffin is infused into one surface to form an anti-adhesive Nepenthes-like slippery liquid-infused porous surface (SLIPS) for isolating defected area with adjacent viscera; while methacrylated gelatin (GelMA) hydrogel is infiltrated into the opposite surface with design of anisotropic microgrooved structures, aiming to facilitate cell adhesion, promote division growth, and induce oriented migration. We have demonstrated that the patch film could promote tissue repair without adhesion-related complications after being implanted into a rat model with abdominal wall defects. These features make such patch film highly versatile for application in regenerative medicine.