Therapeutic microneedles for myocardial repair.

Local myocardial delivery remains an unmet need in cardiovascular disease, as systemic therapies are hindered by cardiac motion, heterogeneous perfusion, and post-infarction extracellular matrix remodeling. Preclinical microneedle (MN) systems enable direct, localized, and sustained epicardial delivery of drugs, proteins, growth factors, and cells while minimizing systemic exposure. Recent studies have demonstrated tangible benefits: galunisertib-loaded MNs reduced fibrosis from ~14% to ~7%, and vascular endothelial growth factor (VEGF)-based MNs increased vascular density from ~0.2 to ~0.5 vessels per field. Mechanically adaptive and biodegradable MN platforms maintain stable contact with the beating heart and support programmable release profiles. This review synthesizes the current preclinical landscape of cardiac MN technologies and outlines the engineering and translational considerations that will guide their advancement toward future clinical applications.