Oxygen-boosted dual-section microneedle patch for enhanced drug penetration and improved photodynamic and anti-inflammatory therapy in psoriasis.

Psoriasis is a prevalent chronic inflammatory skin disorder, characterized by epidermal thickening and an inflammatory hypoxic microenvironment, which significantly hinder drug penetration through the thickened skin and limit the efficacy of photodynamic therapy (PDT). Here, we introduce a dual-section microneedle (MN) patch (termed S-PTP MN patch) to enhance the therapeutic efficacy of psoriasis treatment. The needle section contains PTP nanoparticles (NPs) loaded with triamcinolone acetonide (TA) and coated with a reactive oxygen species (ROS)-responsive layer, while the base section of the patch encapsulates sodium percarbonate (SPC) particles that serve as oxygen generators to facilitate deep penetration of the PTP NPs into inflammatory sites and improve PDT efficacy. Moreover, the PTP NPs enable sustained release of TA drug over 6 days, demonstrating potent anti-inflammatory activity. In an imiquimod-induced psoriatic mouse model, a single application of the S-PTP MN patch demonstrated superior therapeutic efficacy compared to the conventional topical TA cream, with significantly alleviated clinical symptoms, reduced epidermal thickness, and lowered inflammatory cytokine levels, highlighting the potential of the S-PTP MN patch as a clinically translatable strategy for effective psoriasis therapy.