Coated sponge spicules for remodeling skin immune homeostasis in psoriasis treatment by releasing self-assembled phospholipid complex nanoparticles.

Psoriasis is an autoimmune skin disease where dendritic cells play a crucial role. In psoriasis topical treatment, pathologically-induced thickening of the stratum corneum and epidermal hyperplasia severely hinder the penetration of drugs into the deep skin, thereby reducing therapeutic efficacy. Here, we developed the curcumin-POPG phospholipid complex coated Sponge Haliclona sp. Spicules (CUR-Ph-SHS) with the supercritical antisolvent-fluidized bed coating (SAS-FB) technology. This innovative formulation was designed to enhance skin permeation and suppress dendritic cell activation in the psoriasis mouse model. Through the process of SAS-FB, the phospholipid complex formed a uniform amorphous coating on CUR-Ph-SHS, which increased the dissolution of the active ingredient and self-assembled into nanoparticles after release. Moreover, the nanoparticles released from CUR-Ph-SHS could be efficiently internalized by dendritic cells, demonstrating superior anti-maturation activity in vitro compared to raw curcumin. Owing to its dual-tip structure and excellent wettability, CUR-Ph-SHS could effectively penetrate the stratum corneum, releasing self-assembled phospholipid complex nanoparticles into the deep skin and draining lymph nodes of psoriasis mice. In addition, the in-vivo anti-psoriasis experiment revealed that CUR-Ph-SHS relieved the psoriasis symptoms and inhibited the expression of inflammatory cytokines in the skin lesions. Meanwhile, CUR-Ph-SHS successfully inhibited the activation of dendritic cells while inducing the proliferation of regulatory T cells. Overall, these findings highlight CUR-Ph-SHS as novel coated microneedles for remodeling skin immune homeostasis in psoriasis topical therapy, suggesting potential applications in treating other skin inflammatory diseases.