Effect of intra-articular injection of adipose stem cells on traumatic osteoarthritis cartilage defects

Abstract

Traumatic osteoarthritis with cartilage defects can lead to mobility problems. Mitotic activity in cartilage is extremely low, and once damaged, repairing can be difficult. The commonly used autologous or allogeneic cartilage transplantation techniques also have certain limitations. In recent years, directed induction of osteoblastic differentiation using adipocytes has been shown to be effective in repairing cartilage defects. However, it is often induced in vitro and is prone to incomplete or over-differentiation. In addition, because of the large differences in the in vivo and in vitro microenvironment, exploring the influence of these differences in the in vivo microenvironment on the directional differentiation of adipose-derived stem cells (ADSCs) and their effect on cartilage repair is necessary. In this study, a cartilage defect model in rabbits with traumatic osteoarthritis of the left knee was established, and different interventions were conducted in different groups. We determined the effect of directly injecting ADSCs into the joints on repairing cartilage defects in rabbits with traumatic osteoarthritis and analyzed the differences in repair time of newly developed cartilage defects and old cartilage frontal defects. The results indicated that the placement of a stent and injection of ADSCs improved the knee joint activity, increased the expression of BMP and TGF-β protein, and reduced the expression of inflammatory factors, including IL-1β, IL-6, IL-17, and TNF-α. No difference was found between the new cartilage defect and the old one. By directly observing the cartilage defect, intervention with ADSCs + scaffold increased the connection between the cartilage defect and the normal tissue and improved the cartilage repair effect. These results indicated that directly injecting ADSCs into the joints is an effective approach for repairing cartilage defects in traumatic osteoarthritis, and it was not affected by the age of the defect.