Microneedles meet photomedicine: emerging strategies for diagnosis and therapy of skin diseases

Abstract

Microneedle technology, a minimally invasive transdermal delivery platform, has attracted increasing attention in dermatology due to its ability to bypass the first-pass effect, reduce injection-associated pain, and achieve precise targeting in the diagnosis and therapy of skin diseases. Beyond drug transport, MNs can serve as multifunctional tools for in situ biosensing, controlled release, and stimuli-responsive modulation through light, heat, pH, and electrical signals within the cutaneous microenvironment. Photomedicine, as a cornerstone of dermatological practice, enables noninvasive visualization and molecular profiling of skin lesions, while photodynamic, photothermal, and photobiological therapies have become integral in managing infections, immune-mediated dermatoses, and benign or malignant cutaneous tumors. The convergence of these two technologies offers new opportunities to enhance light penetration, improve therapeutic selectivity, and achieve spatiotemporal control of treatment. This review systematically summarizes advances in microneedle-assisted photomedicine for skin diseases, including diagnostic strategies such as optical clearing, fluorescence imaging, and biomarker detection, as well as therapeutic approaches such as direct phototherapy, photodynamic therapy, photothermal therapy, and light-controlled drug release. Furthermore, it discusses key design principles, technical challenges, and clinical translation pathways, aiming to provide theoretical guidance and a strategic framework for future dermatological applications.