Microneedle-Mediated Adaptive Phototherapy (MAP) Wound Patch with Microlens

This paper reports on a new light-delivery approach for wound-healing therapy that integrates microneedles with converging microlenses and a pH -responsive actuation mechanism, referred to as microneedle-mediated adaptive phototherapy (MAP) wound patch. The device consists of a$3 \times 3$microneedle array integrated with planoconvex microlenses, gelatin, and pH -sensitive hydrogel, enabling controlled penetration depth and localized light guidance. Notably, the microneedles enhance light guidance into the tissue, with microlenses resulting in a significant increase in energy density at the cellular level. Our optical testing with a 660 nm LED showed that the microlenses nearly doubled the transmitted irradiance compared to no-lens controls. The MAP-mediated red-light therapy accelerated NIH-3T3 scratch closure in vitro and increased fibroblast viability at low fluences, indicating a dose-dependent photobiomodulation (PBM) effect. These results demonstrate the feasibility of MAP as a platform for targeted, depth-adjustable wound phototherapy.