Development of a Controllable Intelligent Drug Delivery System for Efficient Treatment of Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is a complex inflammatory disease of the joints, which is often accompanied by degeneration of articular cartilage and bone erosion, seriously affecting the quality of life and psychological state of patients. RA is difficult to be cured completely, and currently the main purpose of relief is through the use of anti-inflammatory and antirheumatic drugs, hormones, and biological agents. Tofacitib is a new type of small molecule inhibitor, which has a good effect in the treatment of RA. The current direct drug delivery method has serious side effects caused by the systemic distribution of the drug, so there is a need to develop an intelligent drug delivery system to realize precise treatment. In this work, tofacitib, gallic acid, targeted molecule folic acid, and Fe(III) were selected to assemble a novel type of artificial controllable nanodrug GF-TF. The self-photoacoustic/magnetic resonance imaging (self-PA/MRI) monitored the enrichment of GF-TF in the lesion in real-time, and artificially regulated the addition of deferoxamine (DFO) at the optimal enrichment. DFO strongly chelates Fe(III) in GF-TF and causes its structure to disintegrate gradually, and the self-PA/MRI signal of GF-TF became weaker while tofacitib began to be released, thus realizing the precise and artificially controlled release of the drug under the guidance of imaging. This nanodrug not only achieves efficient aggregation of drugs in inflamed joints, but also achieves real-time monitoring and precise control of drug release through self-PA/MRI, providing a new strategy for the precise treatment of RA.