Direct transplantation of mesenchymal stem cells into the knee joints of Hartley Strain guinea pig with spontaneous osteoarthritis.

摘要

ABSTRACT: INTRODUCTION: Mesenchymal stem cells (MSCs) can differentiate into various connective tissue cells. Several techniques have been used for the clinical application of MSCs in articular cartilage repair, however, there are many issues associated with the selection of the scaffold material, including its ability to support cell viability and differentiation and its retention and degradation in situ. The application of MSCs via a scaffold also requires a technically demanding surgical procedure. The aim of this study was to test the outcome of intra-articular transplantation of mesenchymal stem cells suspended in hyaluronic acid (HA) in the knee joints of Hartley strain guinea pigs with spontaneous osteoarthritis (OA). METHODS: Commercially-available human MSCs were cultured, labeled with carboxyfluorescein diacetate succinimidyl ester (CFDA-SE), suspended in either phosphate-buffered-saline (PBS) or HA, and injected into the knee joints of 7-month-old animals. The control animals were injected with either PBS or HA alone. The animals were sacrificed at 1, 3, and 5 weeks post-transplantation and the knee joints harvested, fluorescent microscopic analysis was performed. Histological and immunohistochemical analysis were performed at 5 weeks post-transplantation. RESULTS: At 5 weeks post-transplantation, partial cartilage repair was noted in the HA-MSC group but not in the other groups. Examination of CFDA-SE-labeled cells demonstrated migration, differentiation and proliferation of MSC in the HA-MSC group. There was strong immunostaining for type-II collagen around both residual chondrocytes and transplanted MSCs in the OA cartilage. CONCLUSIONS: This scaffold-free and technically un-demanding technique appears to result in the regeneration of articular cartilage in the spontaneous OA animal model. Although further examination of the long-term effects of transplantation is necessary, the findings suggest that intra-articular injection of a mixture of MSCs-HA is potentially beneficial for OA.