Hierarchical Structures of Protein-Fiber-Infused Aminoglycan Hydrogels to Promote Myocardial Repair.

Myocardial infarction (MI) is followed by irreversible damage to the myocardium, which eventually evolves into ventricular remodeling and heart failure. An imbalanced inflammatory response after MI can exacerbate myocardial injury. Current strategies to modulate inflammation and thereby improve myocardial tissue repair are limited. Material surface microstructures can modulate the immune microenvironment and thus influence the tissue damage repair process. Therefore, modulation of the postinfarction immune microenvironment through the hierarchical structure of materials becomes a feasible strategy. In this study, hierarchically structured hydrogels were prepared using a polysaccharide gel matrix and a protein fiber network to modulate the postinfarction immune microenvironment. The hierarchical structure of the hydrogel was able to recruit macrophages and further promote the multicellular response of endothelial cells and cardiomyocytes, resulting in angiogenesis and cardiomyocyte survival by modulating macrophage conversion to the M2 type. In the MI model, the hierarchically structured hydrogels effectively reduced the infarct area, increased the ventricular wall thickness, and improved cardiac contractile function. This study is based on the structural modification of materials to facilitate myocardial defect repair, which is expected to provide ideas for the current treatment paradigm after myocardial injury.