Enhancing Deep-Seated Melanoma Therapy through Wearable Self-Powered Microneedle Patch.

Effective treatment of deep-seated tumors relies on enhanced drug penetration in transdermal drug delivery systems. While microneedles (MNs) and iontophoresis techniques have shown improved transdermal drug delivery efficiency, challenges such as skin elasticity, high electrical resistance of the stratum corneum, and external power supply requirements hinder their efficacy in treating deep-seated tumors. In this study, a wearable, self-powered MN patch that integrates a flexible triboelectric nanogenerator (F-TENG) is presented, aimed at advancing deep-seated tumor therapy. MNs are composed of water-soluble materials mixed with negatively charged pH-responsive nanoparticles (NPs) loaded with therapeutic drugs. The F-TENG harnesses personal mechanical movements generate electrical energy. Leveraging the advantages of both MNs and F-TENG, therapeutic NPs can penetrate deep skin locations upon MN patch insertion, releasing drugs rapidly in acidic tumor tissues. Owing to these features, a single administration of the integrated MN-patch in a mouse model with deep-seated melanoma exhibits superior therapeutic efficacy in inhibiting deep-located tumor compared to using the MN-patch alone, indicating promising potential for treating tumors at deep sites.