Mitoprotective therapy preserves chondrocyte viability and prevents cartilage degeneration in an ex vivo model of posttraumatic osteoarthritis

Delco ML, Bonnevie ED, Szeto HS, Bonassar LJ, Fortier LA · Journal of Orthopaedic Research

SS-31 given up to 6 hours after impact cut impact-induced chondrocyte death by 37-48%, leaving viability statistically indistinguishable from un-injured controls, prevented apoptosis, roughly halved cell-membrane damage, and blocked the ~30% impact-induced GAG loss; in adult bovine cartilage it halved impact-induced death. Delaying treatment to 12 hours lost both the viability and the matrix effect. SS-31 was withdrawn from the medium at 24 hours in every arm.

Population

Cartilage explants from the medial femoral condyles of 8 neonatal calves given a single rapid impact injury (24.0 MPa), with a two-animal adult-bovine confirmation

Intervention

SS-31 1 µM added immediately or 1, 6, or 12 hours after impact, cultured up to 7 days

Comparator

Injured untreated and uninjured explants

Limitations

Ex vivo explants, mostly neonatal bovine tissue; the abstract claims benefit at all treatment times but the paper's own data show the 12-hour-delay group was no different from untreated injury, and the authors note that arm also had the shortest drug exposure; co-author Szeto invented the SS peptides, and Stealth supplied the SS-31. NIH, Weill Cornell and Zweig Fund grants.