ICAM-1 targeted thermal-sensitive micelles loaded with tofacitinib for enhanced treatment of rheumatoid arthritis via microwave assistance

Rheumatoid arthritis (RA) is an immune-mediated inflammatory disease without effective treatment. Tofacitinib (TOF) is a JAK inhibitor that can be used for RA therapy, but it still faces the problems of nonspecific distribution and relatively low therapeutic effect. Herein, ICAM-1-modified TOF-loaded P(AN-co-AAm)-PEG micelles (AI-TM) were developed, which can result in an enhanced RA therapy when combining with microwave hyperthermia (MH). It was found that AI-TM could rapidly release the encapsulated TOF under a thermal condition of >43 °C, which was due to the fact that the polymeric micelles has an upper critical solution temperature (UCST) of 43 °C. AI-TM could specifically distribute into the inflamed joints of RA mice, which is associated with the high affinity between anti-ICAM-1 and overexpressed ICAM-1 receptors. Moreover, the combination of AI-TM and MH could result in a remarkably enhanced anti-rheumatic activity, which was related to the RA-targeted ability of AI-TM, the rapid TOF release under MH, and the combined effect between TOF and MH treatment. Our study definitely provides a novel strategy for effective treatment of RA.