Paintable Decellularized‐ECM Hydrogel for Preventing Cardiac Tissue Damage

The tissue‐specific heart decellularized extracellular matrix (hdECM) demonstrates a variety of therapeutic advantages, including fibrosis reduction and angiogenesis. Consequently, recent research for myocardial infarction (MI) therapy has utilized hdECM with various delivery techniques, such as injection or patch implantation. In this study, a novel approach for hdECM delivery using a wet adhesive paintable hydrogel is proposed. The hdECM‐containing paintable hydrogel (pdHA_t) is simply applied, with no theoretical limit to the size or shape, making it highly beneficial for scale‐up. Additionally, pdHA_t exhibits robust adhesion to the epicardium, with a minimal swelling ratio and sufficient adhesion strength for MI treatment when applied to the rat MI model. Moreover, the adhesiveness of pdHA_t can be easily washed off to prevent undesired adhesion with nearby organs, such as the rib cages and lungs, which can result in stenosis. During the 28 days of in vivo analysis, the pdHA_t not only facilitates functional regeneration by reducing ventricular wall thinning but also promotes neo‐vascularization in the MI region. In conclusion, the pdHA_t presents a promising strategy for MI treatment and cardiac tissue regeneration, offering the potential for improved patient outcomes and enhanced cardiac function post‐MI. The heart decellularized extracellular matrix (hdECM) is one well‐known factor for the myocardial infarction (MI) regeneration. Here, a novel hdECM delivery method using paintable hydrogel with no size or shape limitations on application is shown. It exhibits stable wet cardiac tissue adhesion that is easily regulated with a simple treatment. Moreover, it demonstrates angiogenesis and MI regeneration abilities upon in vivo implantation.