Photothermal-Augmented CoP-Carbon Polyhedral Nanozyme: Redox Homeostasis and Immune Reprogramming Mediated Psoriasis Therapy.

Psoriasis, a chronic inflammatory skin disease characterized by oxidative stress and dysregulated immunity, necessitates innovative therapies to overcome the limitations of conventional treatments. This study introduces cobalt phosphide nanoparticles deposited on carbon polyhedral frameworks (CoP-C PFs) as a multifunctional nanoplatform integrating enzyme-mimicking catalysis and photothermal activity for synergistic psoriasis management. CoP-C PFs exhibit superior catalytic efficiency, with low Michaelis-Menten constants (e.g., Km = 0.26 mM for H2O2 decomposition), enabling potent reactive oxygen species (ROS) scavenging to alleviate oxidative damage in RAW264.7 macrophages and HaCaT keratinocytes. Under 808 nm near-infrared irradiation, CoP-C PFs exhibit a high photothermal conversion efficiency of 68.6%, enabling precise control of the local temperature to generate localized hyperthermia to enhance catalytic ROS elimination and antibacterial activity. In an imiquimod-induced psoriatic murine model, CoP-C PFs alleviated inflammation by restoring redox balance, suppressing CD3+ T cell/F4/80+ macrophage infiltration, modulating IL-17A/IL-23 and TNF-α/NF-κB pathways, and promoting M2 macrophage polarization (increased CD206+/CD68+ ratio), resulting in epidermal normalization and reduced abnormal keratinization without organ toxicity, underscoring effectiveness and biosafety. By integrating photothermal enhancement with multienzyme catalysis, this "all-in-one" nanozyme platform enables dual regulation of oxidative stress and immune microenvironment, offering a promising therapeutic strategy for psoriasis and other inflammatory skin disorders.