Partitioned Microneedle Patch Based on NO Release and HSP Inhibition for mPTT/GT Combination Treatment of Melanoma

Photothermal therapy (PTT) shows promise in cancer treatments due to its good spatiotemporal selectivity and minimal invasiveness. However, PTT has some problems such as excessive heat damage to normal tissues, tumor thermo-resistance caused by heat shock proteins (HSPs), and limited efficacy of monotherapy. Here, we construct a patch named "partitioned microneedles" (PMN-SNAP/CuS), which separates the "catalyst" bovine serum albumin-based copper sulfide nanoparticles (CuS@BSA NPs) and the "reactant" <i>S</i>-nitroso-<i>N</i>-acetylpenicillamine (SNAP) into different regions of microneedles, for enhancing mild PTT (mPTT) of melanoma. PMN-SNAP/CuS showed an excellent photothermal effect, Fenton-like catalytic activity, and nitric oxide (NO) generation ability. The combination of NO and reactive oxygen species (ROS) produced by PMN-SNAP/CuS effectively blocked the synthesis of HSPs at the source and enhanced the efficacy of mPTT. Both in vitro and in vivo results proved that PMN-SNAP/CuS significantly enhanced the inhibition of melanoma under 808 nm laser irradiation. In conclusion, our partitioned microneedle strategy based on the combination of enhanced mPTT and gas therapy (GT) provides a promising approach to enhance the therapeutic effect on melanoma.