Microneedles: A Promising Therapeutic Strategy for Next-Generation Drug Delivery, Diagnosis and Biosensing

Microneedles (MNs) have emerged as a transformative drug delivery technology, offering a minimally invasive, painless alternative that bridges the gap between conventional injections and topical therapies. Initially developed for transdermal delivery, MNs have rapidly evolved into multifunctional platforms capable of administering diverse therapeutic agents, with enhanced precision and bioavailability. Recent innovations have extended MN applications far beyond the skin, enabling closed-loop therapeutic systems through integration with biosensors and stimuli-responsive release mechanisms for the treatment of chronic diseases such as diabetes and cancer. Expanding beyond human medicine, MNs are also being explored in plant science for precise agrochemical delivery and real-time physiological monitoring. Moreover, the adaptability of MNs has led to their successful deployment in challenging anatomical sites, including the oral cavity, eyes, and myocardium, enabling localized and targeted treatments. As the field advances, key challenges remain in material optimization, scalable manufacturing, and clinical translation. Looking forward, the convergence of MNs with wearable technologies and artificial intelligence holds promise for achieving personalized, data-driven therapeutic interventions. This review highlights the recent progress, diverse applications, and future potential of MNs as a next-generation delivery and diagnostic platform.