Polymeric Micelles for the Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) affects around 1% of the world's population and places heavy burdens on patients and society. RA pathogenesis has been studied for centuries, and findings suggest that it is activated by varied factors such as infection, genetic activation, and environmental changes, and travels differential pathways in patients, which increases the difficulty of treatment. There is currently no cure for RA. Current treatments inhibit inflammation, protect joints, and suppress immune cells like macrophages and T-lymphocytes. However, these therapies usually have issues of ineffectiveness, drug resistance, and many side effects. The reason is that therapies like methotrexate (MTX), dexamethasone (Dex), and cyclosporine A (CsA) are very lipophilic and have broad distribution in vivo. Micelles are ideal carriers to increase the solubility, bioavailability, half-life, and targeting of these hydrophobic drugs, and thus can be used for RA treatment. In the past decade, micelle-based therapies have become an attractive new strategy for RA treatment. This review summarizes the merits of micelles for RA, the therapeutic targets for RA, and studies that show the recent progress of developed micelles for RA. We compare the composition, performance, potential merits, and limitations of current therapies, and discusses the future directions of advanced and smart micelles for RA.