Advances in Hydrogel Drug Delivery Systems for Myocardial Infarction Treatment.

Myocardial infarction (MI) has the highest mortality rate among cardio-vascular diseases. Hydrogel biomaterials mimicking the extracellular matrix (ECM) have recently demonstrated excellent biocompatibility, low immunogenicity, favorable biode-gradability, and multifunctionality, showcasing significant potential for MI treatment. Hydrogels can provide mechanical support to the damaged myocardium, alleviating pathological remodeling. Moreover, their porous structure makes them ideal carriers for localized and sustained drug delivery. Hydrogels derived from various matrices-including polysaccharides, polypeptides, proteins, decellularized extracellular matrix (dECM), and synthetic polymers-exhibit distinct properties in terms of biocompatibility, mechanical performance, and drug delivery capacity. These hydrogels support tissue regeneration and enable targeted release of diverse therapeutics, meeting the varied therapeutic demands of myocardial repair. Specific signals within the MI microenvironment-such as low pH, overexpression of specific enzymes, and elevated reactive oxygen species (ROS) levels-can trigger responsive drug release from hydrogels, significantly enhancing therapeutic efficacy while reducing systemic side effects. This review summarizes recent advances in hydrogel-based drug delivery systems for MI treatment, focusing particularly on the characteristics and advantages of different hydrogel materials for myocardial repair. Furthermore, the responsive drug release behavior of hydrogels is analyzed in the context of the cardiac injury microenvironment, providing a reference for future research.