Breaking the skin barrier: How nanoparticle-loaded microneedles are poised to redefine drug delivery

Microneedle-mediated nanoparticle delivery (MND) has emerged as a transformative approach in transdermal drug delivery because it integrates the benefits of nanoparticles, such as improving drug stability, targeted delivery, and controlled release, with the minimally invasive and patient-compliant characteristics of microneedles (MNs). These hybrid systems enable the delivery of multifunctional nanomedicines, presenting significant potential to revolutionize the prevention and treatment of a wide range of diseases. In addition, compared to conventional microinjections, the minimally invasive and patient-friendly nature of MNs results in reduced pain and discomfort for patients. This review highlights recent advancements in nanoparticle-integrated MN technology for treating cancer, immune disorders, skin diseases, pain management, and diabetes. The synergistic combination of MNs with nanocarriers, such as polymeric nanoparticles, liposomes, and metal-based nanostructures, to enable precise drug localization, control drug release, reduce systemic toxicity, and enhance therapeutic response is also reviewed, demonstrating how nanoparticle-loaded MNs may revolutionize non-invasive drug delivery as an efficient, painless, and patient-compliant formulation. Additionally, we discuss the challenges and future directions in optimizing these systems for clinical translation.