Engineering of Low Shrinkage Foams Stabilized by Metal-Phenolic Networks for Wound Healing

Lightweight porous materials hold immense potential across industrial and biomedical applications, while conventional fabrication methods face challenges including energy-intensive drying processes, structural collapse, and limited mechanical strength. Herein, we report a universal strategy to engineer robust dry foams stabilized by metal-phenolic networks (MPNs) through a synergistic combination of high-speed mechanical foaming and freeze-thaw drying process. By introducing carboxymethyl chitosan (CMCS) and metal ions for rapid cross-linking, the foam templates can be stabilized to overcome the instability of conventional foams, enhancing solvent exchange efficiency and achieving hierarchical porosity. The integration of metal-phenolic coordination during the freeze-thaw process further reinforces the CMCS skeletal framework, yielding materials with exceptional mechanical integrity (<16% shrinkage and >80 kPa Young's modulus) and ambient-drying compatibility. The resultant MPN-stabilized dry foams (MPN foams) exhibit excellent antibacterial activity and angiogenesis promotion for wound healing applications.