Research progress of microneedle drug delivery system in the treatment of autoimmune diseases.

Autoimmune diseases represent a heterogeneous group of disorders characterised by immune system dysregulation, wherein aberrant responses to self-antigens result in cellular and tissue damage. According to statistics, there are over 80 different types of autoimmune diseases worldwide, among which psoriasis and rheumatoid arthritis (RA) are relatively common. Current therapeutic strategies emphasise long-term management to mitigate symptoms and retard disease progression. Conventional approaches, including systemic administration of oral medications, injectables, and biologics, are frequently limited by adverse effects that compromise patient adherence. In contrast, the use of microneedle (MN) technology as a minimally invasive transdermal delivery platform has emerged as a promising alternative, offering distinct advantages such as painless self-administration, enhanced patient compliance, localised delivery to disease-specific sites (e.g. skin lesions in psoriasis, inflamed joints in RA), and improved bioavailability of immunomodulatory agents while minimising systemic toxicity. This review systematically examines MN classification, immunomodulatory mechanisms, and therapeutic efficacy in autoimmune disease management, while also providing a critical assessment of MN biosafety and clinical translation challenges in autoimmune patients. Furthermore, it highlights recent advancements in MN technology for prevalent autoimmune disorders, with the goal of informing future innovation and accelerating clinical translation.