Mesoporous polydopamine@CeO2 nanoparticles for photoacoustic-guided photothermal therapy in suppressing arthritis.

Rheumatoid arthritis (RA) is characterized by poor oxygen supply and overproduction of reactive oxygen species (ROS), thereby exacerbating synovial inflammation. We synthesized MPDA@CeO2 nanoparticles (NPs) by incorporating mesoporous polydopamine (MPDA) NPs and CeO2 for photoacoustic imaging (PAI)-guided synergistic light-controlled PTT/oxygen-boosting/ROS-eliminating therapy. Upon irradiation with a near-infrared (NIR) laser, MPDA@CeO2 NPs trigger photothermal conversion to eradicate inflammatory cells and release CeO2, which have a catalytic activity to eliminate ROS and release oxygen. The oxygen-release and ROS-depleting efficiency was simultaneously augmented by heat to further combat the harmful environment of inflammation. We validated the therapeutic effect of MPDA@CeO2 in vitro and in vivo. We further applied multiwavelength PAI to observe the distribution of NPs and the change in oxygen saturation during the treatment process in vivo. The study highlights the therapeutic value of MPDA@CeO2 in inhibiting arthritis in RA through imaging-guided synergistic therapy.