Immunomodulatory nano-preparations for rheumatoid arthritis.

Rheumatoid arthritis (RA) is a systemic autoimmune disease (AD) caused by the aberrant attack of the immune system on its own joint tissues. Genetic and environmental factors are the main reasons of immune system impairment and high incidence of RA. Although there are medications on the market that lessen disease activity, there is no known cure for RA, and patients are at risk in varying degrees of systemic immunosuppression. By transporting (encapsulating or surface binding) RA-related self-antigens, nucleic acids, immunomodulators, or cytokines, tolerogenic nanoparticles-also known as immunomodulatory nano-preparations-have the potential to gently regulate local immune responses and ultimately induce antigen-specific immune tolerance. We review the recent advances in immunomodulatory nano-preparations for delivering self-antigen or self-antigen plus immunomodulator, simulating apoptotic cell avatars in vivo, acting as artificial antigen-presenting cells, and based on scaffolds and gels, to provide a reference for developing new immunotherapies for RA.

Nanoemulsions Target to Ectopic Lymphoids in Inflamed Joints to Restore Immune Tolerance in Rheumatoid Arthritis.

Inducing immune tolerance through repeated administration of self-antigens is a promising strategy for treating rheumatoid arthritis (RA), and current research indicates that coadministration of immunomodulators can further orchestrate the tolerogenic response. However, most of the clinical trials based on tolerance induction have negligible therapeutic effects. Peripheral lymphoid organs play critical roles in immunotherapy. Here, we design an engineered nanoemulsion for targeted codelivery of self-antigens and an immunomodulator to ectopic lymphoid structures (ELSs) in inflamed joints of RA. Namely, a citrullinated multiepitope self-antigen (CitP) and rapamycin are incorporated into the nanoemulsions (NEs@CitP/Rapa), which are fabricated by a facial method using commercialized pharmaceutical excipients. After intravenous administration, the nanoemulsion shows satisfactory accumulation in the inflamed paws and provides enhanced anti-inflammatory effect in various experimental murine models of RA. Our study provides a promising targeting strategy to induce immune tolerance for the treatment of RA.