Biomedical PCL Janus patch with mushroom-structured wet adhesive and PEG-coated anti-adhesive surface.

Simultaneously achieving tissue adhesion and anti-adhesion remains a fundamental challenge for biomedical patch development. Here, we developed a PCL-based Janus patch that combines wet adhesion mediated by mushroom-shaped microstructures with an anti-adhesive surface formed by UV-crosslinked PEG. The mushroom-structured surface enhanced wet adhesion, whereas the PEG-coated surface reduced nonspecific fibroblast attachment, enabling spatially separated adhesive and anti-adhesive functions within a single PCL platform.