Silk fibroin and hydroxypropyl cellulose composite injectable hydrogel-containing extracellular vesicles for myocardial infarction repair.

Extracellular vesicles (EVs) have been recognized as one of the promising specific drugs for myocardial infarction (MI) prognosis. Nevertheless, low intramyocardial retention of EVs remains a major impediment to their clinical application. In this study, we developed a silk fibroin/hydroxypropyl cellulose (SF/HPC) composite hydrogel combined with AC16 cell-derived EVs targeted modification by folic acid for the treatment of acute myocardial infarction repair. EVs were functionalized by distearoylphosphatidyl ethanolamine-polyethylene glycol (DSPE-PEG-FA) via noncovalent interaction for targeting and accelerating myocardial infarction repair. In vitro , cytocompatibility analyses revealed that the as-prepared hydrogels had excellent cell viability by MTT assay and the functionalized EVs had higher cell migration by scratch assay. In vivo , the composite hydrogels can promote myocardial tissue repair effects by delaying the process of myocardial fibrosis and promoting angiogenesis of infarct area in MI rat model.