Reversing detrimental effects of OA-related terminal maturation in high-throughput in vitro and biomimetic ex vivo human models

Osteoarthritis (OA) lacks disease-modifying therapies, in part due to limited human-relevant preclinical models. OA pathophysiology is characterized by loss of chondrocyte maturation arrest, producing growth plate–like changes and terminal differentiation. We aimed to establish a scalable human organoid-based platform for efficient therapeutic screening. Cartilage organoids were derived from OA patient tissues in a 96-well format and benchmarked against matched osteochondral explants. Terminal maturation was induced using triiodothyronine (T3). Three candidate compounds, all thyroid hormone receptor blockers, were tested across dose ranges and incubation times. The most effective compound was validated in a human biomimetic osteochondral explant model to assess translational relevance. The high-throughput organoid platform consistently reproduced hypertrophic responses, closely mirroring osteochondral explant behavior, and provided reliable readouts of terminal maturation marker CCDC80 , Of the three compounds evaluated, Compound A demonstrated the strongest effects, significantly increasing CCDC80 mRNA and MMP3 protein levels in the organoid system. In the osteochondral explant model, Compound A reversed T3-induced terminal maturation, suppressing markers including CCDC80 , PHOSPHO1 , and MMP3 . This study introduces a scalable and reproducible preclinical screening strategy using human OA tissues for compound evaluation. The platform enables efficient dose-response testing and identifies thyroid signaling as a promising therapeutic axis for modulating chondrocyte maturation. These findings suggest a novel approach to slow OA progression, preserve joint function, and improve mobility and quality of life in affected individuals.