Mass General Brigham researchers reported a disease‑severity‑responsive nanoparticle platform (MINT) that preferentially delivers ghrelin mRNA to cartilage regions undergoing glycosaminoglycan loss, a hallmark of osteoarthritis. Published in Nature Nanotechnology, the approach exploits electrostatic changes in diseased tissue to repel particles from healthy cartilage and concentrate them in damaged lesions, increasing payload to the worst areas. In mouse OA models, ghrelin mRNA via MINT reduced cartilage degeneration, inflammation and pain signaling. The platform offers a precision delivery solution that may generalize to other localized mRNA therapies.