• • SA-PBA/E/Sr hydrogel reduced infarct size and increased left ventricular wall thickness, with Masson's staining showing significantly less collagen deposition (blue) compared to MI groups (***P < 0.001), indicating effective mitigation of fibrosis and scar tissue formation.
• • The hydrogel promoted macrophage polarization from pro-inflammatory M1 to anti-inflammatory M2 phenotype, decreasing TNF-α secretion and increasing IL-10 production, which is critical for resolving inflammation and fostering a pro-repair microenvironment.
• • Incorporation of Sr2+ significantly enhanced endothelial cell migration, a key factor in angiogenesis, leading to accelerated neovascularization in the infarcted tissue, as evidenced by increased vessel density.
• • Echocardiographic analysis demonstrated a remarkable increase in ejection fraction and reduced left ventricular dilation, confirming significant cardiac functional recovery after SA-PBA/E/Sr treatment compared to other groups.