Abstract: Objective To explore the techniques of constructing tissue engineered meniscus with bone marrow mesenchymal stem cells (BMSCs) in dog model in vitro. Methods Biodegradable scaffolds in shape of meniscus were fabricated with polyglycolic acid (PGA) and polylactic acid (PLA) by mold. BMSCs were harvested from bone marrow of dogs and cultured in vitro. Then the expanded cells were seeded onto the scaffolds, and transferred to chondrogenic medium after 5 days. Gross observation, histological observation and biomechanical test were carried out after cultured for 6 weeks. Results The constructs cultured in vitro for 6 weeks maintained three-dimensional structure of meniscus approximately, and formed smooth white cartilage-like tissue with elasticity. HE staining showed typical mature lacuna, suggesting the formation of mature cartilage tissue. Safranin'O staining showed abundant proteoglycan. Biomechanical analyses indicated that Young's modulus of constructs can reach 13.2% of native meniscus. Conclusion BMSCs can differentiate into heterogeneous cartilage-like tissue successfully through cultivation of inducing system, and construct tissue engineered meniscus in vitro.

Key words: Bone marrow mesenchymal stem cells, Tissue engineered meniscus, Polyglycolic acid/polylactic acid scaffold