Hydrogels loaded with different substances for treating heart failure: a promising therapy.

Acute myocardial infarction (AMI), which causes cardiomyocyte death due to ischemia, affects ∼7 million people annually worldwide, and its mortality rate is greater than one-third. Furthermore, AMI severely impairs cardiac function, leading to heart failure and fatal arrhythmias. While timely reperfusion improves survival, adverse remodeling and subsequent heart failure remain major challenges. After cardiomyocyte death, excessive fibrosis in and around the infarct decreases heart size and impairs cardiac function, leading to heart failure. Current end-stage treatments (e.g., drugs and devices) cannot repair damaged tissue, but injectable biomaterials, particularly hydrogels, offer promising new therapeutic strategies; their excellent biocompatibility, degradability, high water content, and injectability allow the targeted delivery of bioactive molecules, drugs, cells, and exosomes (exos) directly into the damaged myocardium to promote repair after AMI. Here, we describe the mechanism of progression from coronary atherosclerotic heart disease to myocardial infarction and myocardial injury and the superiority of hydrogels for treating this disease. We also discuss the mechanisms of action of different bioactive molecules, drugs, cells, exos, miRNA and two therapeutic agents-loaded hydrogels for treating myocardial injury and the experimental effects of these hydrogels. Finally, we discuss the existing problems associated with injectable hydrogels and the prospects of using hydrogel formulations in the treatment of myocardial infarction.