Cartilage Endplate‐Targeted Engineered Exosome Releasing and Acid Neutralizing Hydrogel Reverses Intervertebral Disc Degeneration

Cartilage endplate cell (CEPC) and nucleus pulposus cell (NPC) inflammation are critical factors that contribute to intervertebral disc degeneration (IVDD). Recent evidence indicated that iron ion influx, reactive oxygen species (ROS), and the cGAS-STING pathway are involved in CEPC inflammatory degeneration. Moreover, cytokines produced by degenerating CEPCs and lactic acid accumulation within the microenvironment significantly contribute to NPC inflammation. Consequently, simultaneous alleviation of CEPC inflammation and correction of the acidic microenvironment are anticipated to reverse IVDD. Herein, CEPC-targeted engineered exosomes loaded with salvianolic acid A are incorporated into a CaCO