Biodegradable Microneedle Patch Confers Crocin with Outstanding Effects in the Treatment of Myocardial Infarction

Crocin (CRO), the main active component of Crocus sativus (saffron), exhibits significant therapeutic potential for the treatment of myocardial infarction (MI). However, its clinical application is hindered by poor oral administration due to the intestinal barrier. To overcome this limitation, a CRO-incorporated biodegradable microneedle (CRO–DMN) patch was developed to transdermally deliver CRO into the bloodstream, enhancing its therapeutic effect against MI. The microneedle patch, fabricated from sodium hyaluronate (HA), demonstrated excellent mechanical strength, effectively penetrating the stratum corneum and facilitating CRO infiltration to a depth exceeding 300 μm successfully. Studies revealed that CRO was fully released within 30 min postapplication, and the skin self-healed within 90 min after patch removal. Importantly, administration of CRO–DMNs to MI mice resulted in significant improvements in cardiac function and reductions in infarct size compared with CRO treatment alone. Additionally, CRO–DMNs also provided superior protective effects on the myocardium and mitochondria and significantly increased angiogenesis in the infarction border area. In conclusion, CRO–DMNs represent a promising transdermal drug delivery system that effectively improves the therapeutic efficacy of CRO in the treatment of MI.