Mechanisms and Research Advances in Drug Delivery Systems for Psoriasis and Atopic Dermatitis.

Inflammatory skin diseases, including psoriasis and atopic dermatitis (AD), are distinguished by their chronic nature, high rates of recurrence, and intricate immune mechanisms, severely compromising patients' physical and mental health. The stratum corneum's innate barrier property contributes to the low bioavailability of conventional topical formulations, while prolonged systemic administration entails substantial systemic toxicity concerns. There is an urgent clinical need for novel therapeutic strategies that balance high transdermal efficacy with safety. The Drug Delivery Systems (DDS) overcome physical barriers through distinct structural and material mechanisms, ranging from lipid fusion and stratum corneum hydration to the minimally invasive construction of physical microchannels. Furthermore, these systems enable precise accumulation and on-demand release of drugs at the target site via stimuli-responsive and biomimetic strategies. This review summarizes the research progress and mechanisms of action for these novel delivery platforms, with a focus on psoriasis and atopic dermatitis. The article provides a theoretical basis for the advancement of the DDS from the management of symptoms to the provision of precise cures by outlining these advancements.