Cerium-cobalt composite nanoparticles (CC NPs) as a multifunctional reactive oxygen species (ROS) scavenger for psoriasis therapy.

Psoriasis is a chronic inflammatory disorder with a worldwide prevalence of 1-3 %, which has no cure. By inducing inflammation, keratinocyte hyperproliferation, and oxidative stress, reactive oxygen species (ROS) play a pivotal role in the pathogenesis of psoriasis. Although the clinical application of ROS-scavenging nanozymes is expected, their translation has been limited by complicated synthesis and high cost. To bypass these problems, in the present study, cerium cobalt composite nanoparticles (CC NPs) were fabricated via facile coprecipitation. The optimization results revealed that 8CC NPs (CeCo = 8:2) were optimal with uniform spherical morphology and enhanced oxygen vacancies, which enhanced the ROS-scavenging activities, and enabled the efficient scavenging of H2O2, O2•-, and •OH radicals. Then, 8CC NPs suppressed the intracellular ROS accumulation, inhibited proliferation, and attenuated the NF-κB inflammatory signaling in the IL-17-stimulated HaCaT keratinocytes. Additionally, in a murine imiquimod-induced psoriasis model, the treatment with 8CC NPs markedly alleviated the clinical symptoms, and no toxicity was observed. Therefore, CC NPs could serve as a novel, cost-effective, and biocompatible nanozyme platform with powerful ROS scavenging, simple synthesis, and promising inflammatory suppression, which provided strong support for their application in the translation of psoriasis. Given the inherent differences between murine models and human psoriasis, further studies are essential to validate the therapeutic potential of this nanozyme platform in clinical settings.