Glass sponge-inspired interpenetrating hydrogel patch achieves rapid wet adhesion, long-term mechanical support, and...

Myocardial patches, particularly collagen-based systems, have emerged as promising therapeutic platforms for repairing injured cardiac tissue after myocardial infarction (MI). However, their clinical translation remains constrained by insufficient wet-tissue adhesion, mechanical mismatch with the native myocardium, and limited regenerative bioactivity. Inspired by the interpenetrating rigid-flexible architecture of deep-sea glass sponge spicules, we developed a biomimetic hydrogel cardiac patch (PCH@D) designed to address these challenges in an integrated manner. The patch is constructed as a multi-component interpenetrating network, in which diatom-derived biosilica serves as a rigid skeletal framework and silicate ion reservoir, while a dual-network matrix of acrylated collagen and poly(acrylic acid), reinforced by catechol-functionalized hyperbranched polymers, forms a flexible organic phase that mediates wet-tissue adhesion through cooperative hydrophobic-catechol interactions by actively displacing interfacial water and forming stable covalent bonds with tissues. As a result, the PCH@D patch achieves rapid and robust adhesion to wet myocardium (40.59 ± 3.30 kPa), exhibits mechanical properties well matched to native myocardium, and offers sustained silicate ion release over 28 days. In a murine MI model, implantation of the PCH@D patch reduced cardiomyocyte apoptosis, promoted M2 macrophage polarization, enhanced angiogenesis, and effectively mitigated adverse ventricular remodeling, leading to improved cardiac function. This work highlights a bioinspired materials design strategy for cardiac patches that integrates mechanical compatibility with active biological regulation.