BACKGROUND:Trauma easily leads to the emergence of articular cartilage defects, which is a difficult problem in the orthopedics field. Tissue engineering technology provides a new method for cartilage repair. OBJECTIVE:To explore the feasibility of combining chitosan and bone marrow mesenchymal stem cels to repair injured articular cartilage in rabbits. METHODS: Cultured rabbit bone marrow mesenchymal stem cels were seeded onto chitosan scaffold, and then the composite material was implanted into the defect as experimental group. Rabbits with no treatment served as control group. Gross observation and toluidine blue staining were carried out at 6 and 12 weeks after operation. RESULTS AND CONCLUSION:At 6 weeks after operation, the control group had only fibrous tissue hyperplasia, and in the experimental group, cartilage-like tissues were generated at the defect site. At 12 weeks after operation, a smal amount of hyaline cartilage-like tissues were observed in the control group, and the defects in the experimental group were covered with smooth and hyaline cartilage tissues. After 12 weeks, the toluidine blue staining was light in the control group with a smal amount of cartilage tissues; in the experimental group, the toluidine blue staining was remarkable, and the defects were completely covered with hyaline cartilage tissues, and cartilage cels were increased in number. The findings indicate that chitosan-bone marrow mesenchymal stem cels composite material is better to induce cartilage tissue formation and promote cartilage defect repair.

BACKGROUND:With respect to mesenchymal stem cels from other sources, synovial mesenchymal stem cels are rich in source, and moreover, the synovial tissue can regenerate quickly after partial hepatectomy and lead to fewer complications, in recent year, which have become a hot spot in stem cel research. OBJECTIVE:To observe the proliferation and directional differentiation of synovial mesenchymal stem cels from osteoarthritis patients. METHODS:Synovial mesenchymal stem cels were isolated and cultured. MTT assay was used to detect cel proliferation ability. Alkaline phosphatase activity was detected quantitatively at 7 days of osteogenic induction, and osteogensis-related gene expression was measured at 7, 14, 21 days of osteogenic induction. Alizarin red staining was performed at 21 days of induction. RESULTS AND CONCLUSION:(1) Passage 3 synovial mesenchymal stem cels proliferated faster, which were in latent period at 1, 2 days after inoculation, in logarithmic growth phase at 3-6 days, and then entered into the plateau phase at 7 days. (2) The activity of alkaline phosphatase was significantly higher in the induction group than the control group at 3, 7, 10 days after osteogenic induction (P < 0.05). The cels were positive for alizarin red staining at 21 days of osteogenic induction, and there were calcium deposits and calcium nodules in the extracelular matrix. (3) Bone-binding protein and Runx2 were visible at 7 days of osteogenic induction, and reached the peak at 21 days. These findings indicate that synovial mesenchymal stem cels from patients with advanced osteoarthritis have strong proliferation ability, which can differentiate into osteoblasts under in vitro induction.