Targeted Chemo-Photothermal Treatments of Rheumatoid Arthritis Using Gold Half-Shell Multifunctional Nanoparticles

We have developed RGD-attached gold (Au) half-shell nanoparticles containing methotrexate (MIX) for the treatment of rheumatoid arthritis (RA), where MIX is the most widely used disease-modifying anti-rheumatic drug (DMARD) for the treatment of RA, and RGD peptide Is a targeting moiety for inflammation. Upon near-infrared (NIR) irradiation, heat Is locally generated due to Au half-shells, and the drug release rate Is enhanced, delivering heat and drug to the inflamed joints simultaneously. RA is a chronic inflammatory disease characterized by synovial inflammation in multiple joints within the penetration depth of NIR light. When combined with NIR irradiation, these nanoparticles containing a much smaller dosage of MIX (1/930 of MIX solution) showed greater therapeutic effects than that of a conventional treatment with MIX solution in collagen-induced arthritic mice. This novel drug delivery system is a good way to maximize therapeutic efficacy and minimize dosage-related MIX side effects In the treatment of RA. Furthermore, these multifunctional nanoparticles could be applied to other DMARDs for RA or other inflammatory diseases.