A chitosan-based multifunctional hydrogel patch improves cardiac health and function by repairing the post-myocardial...

Myocardial infarction (MI) induced ischemia and hypoxia trigger a complex pathological microenvironment characterized by oxidative stress, inflammation, and fibrosis. However, the existing surgical and pharmacological treatments, as well as some tissue engineering techniques, fail to adequately therapy these symptoms, ultimately leading to cardiac dysfunction and poor prognosis. In this study, a multifunctional hydrogel patch composed of chitosan (CS), intrinsically hierarchical silk fibroin (SF) fibers, and reactive oxygen species (ROS) scavenging tannic acid (TA) for cardiac implantation was developed for treating the intricate post-MI microenvironment. This hydrogel not only provides favorable mechanical compliance but also enables sustained release of TA for over 30 days, ensuring long-term ROS scavenging while promoting cardiomyocyte adhesion and survival. In vitro experiments, the hydrogel demonstrates favorable biocompatibility and achieves an effective ROS clearance rate of approximately 80%. In a rat MI model, implantation of the patch reduces inflammatory factor secretion, decreases the myocardial fibrosis area by approximately 25%, and improves the ejection fraction (EF%) by approximately 20% for over 28 days post-MI. Mechanistically, the hydrogel patch synergistically regulates PI3K/Akt, Wnt5a/β-catenin, and TGF-β/Smad5 signaling pathways. In summary, this hydrogel patch offers a promising target strategy for repairing the complex post-MI microenvironment.