[Effect of rolling compression loading bioreactor on chondrogenesis of rabbit bone marrow mesenchymal stem cells with different loading parameters].

OBJECTIVE: To explore the effect of rolling compression loading bioreactor on chondrogenesis of rabbit bone marrow mesenchymal stem cells (BMSCs) with different loading parameters.

METHODS: BMSCs were isolated from New Zealand rabbits, aged 2.5 months. BMSCs at passage 3 were used to prepare BMSCs-agarose gels (4 mm in diameter and height, respectively). Samples were divided into 8 groups: 10% (group A1), 20% (group A2), and 30% (group A3) compression groups (0.4 Hz, 3 h/d) and 20 minutes (group B1), 3 hours (group B2), and 12 hours (group B3) rolling time groups and static culture (control groups). The living cell rate, the collagen type II and Aggrecan gene expressions, and glycosaminoglycan (GAG) content were determined, and histological staining was done at 24 hours, 7 days, 14 days, and 21 days after culture.

RESULTS: At 14 and 21 days, the living cell rates of groups A1 and A2 were significantly higher than that of group A3 (P < 0.05), groups B1 and B2 were significantly higher than group B3 (P < 0.05). Collagen type II and Aggrecan gene expressions of the experimental groups at each time point were significantly higher than those of the control groups (P < 0.05); at 14 and 21 days, collagen type II and Aggrecan gene expressions of groups A1 and A2 were significantly higher than those of group A3, and groups B1 and B2 were also significantly higher than group B3 (P < 0.05). At 14 and 21 days, the GAG contents of groups A1 and A2 were significantly higher than those of group A3 (P < 0.05); groups B1 and B2 were also significantly higher than group B3 (P < 0.05). At 21 days, toluidine blue staining showed that obvious blue-staining and even cartilage lacunae were seen in groups A2 and B2, but light and quite rare blue-staining in groups A1, A3, B1, and B3.

CONCLUSION: The rolling compression loading bioreactor has great promotion effect on chondrogenesis of rabbit BMSCs with rolling parameters of 0.4 Hz, 3 hours, and 20% compression.