1. Department of Sports Medicine and Joint Surgery, Hokkaido University Graduate School of Medicine, Sapporo 060‐8638, Japan;2. Department of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo 060‐0810 Japan;3. Department of Orthopedic Surgery, Faculty of Medicine, University of the Ryukyu, Okinawa 903‐0215, Japan;4. Department of Photobiology, Hokkaido University Graduate School of Medicine, Sapporo 060‐8638, Japan;5. RIKEN Wako Institute, Wako 351‐0198, Japan
Abstract:
We have developed a novel method to induce spontaneous hyaline cartilage regeneration in vivo for a large osteochondral defect by implanting a plug made from a double‐network hydrogel composed of poly(2‐acrylamido‐2‐methylpropanesulfonic acid) and poly(N,N′‐dimethylacrylamide) at the bottom of the defect, leaving the cavity vacant. In cells regenerated in the treated defect, type‐2 collagen, Aggrican, and SOX9 mRNAs were highly expressed and the regenerated matrix was rich in proteoglycan and type‐2 collagen at 4 weeks. This fact gave a significant modification to the commonly established concept that hyaline cartilage tissue cannot regenerate in vivo. This study prompted an innovative strategy in the field of joint surgery to repair an osteochondral defect using an advanced, high‐function hydrogel.
