Abstract: Objective To study the effect of bone marrow mesenchymal stem cells(BM-MSCs) combined with chitosan composite hydrogel loaded with transforming growth factor beta 3 (TGF-β3) to repair meniscus defects. Methods A full-thickness defect model of the anterior horn of the meniscus was developed in 60 New Zealand white rabbits. They were randomly divided into: the control group which did not implant any materials. The repair group Ⅰ in which chitosan composite hydrogel and bone marrow mesenchymal stem cells composite were injected into the defect group, and in group Ⅱ,the chitosan composite hydrogel loaded with TGF-beta 3 and bone marrow mesenchymal stem cells complex were repaired. After 12 weeks of operation, the samples were taken for radiology, gross and histological observation. Western blot was used to detect type Ⅱ collagen and proteoglycan protein. Results In the control group, the full-thickness defect of the meniscus anterior horn was not obviously repaired; in the repair group Ⅰ,most of the defects were filled with repaired tissue; in the repair group Ⅱ, the defects were completely filled with repaired tissue. The expression level of type Ⅱ collagen and proteoglycan protein in repair group Ⅱ was higher than that in control group (P＜0.05). Conclusions Bone marrow mesenchymal stem cells combined with chitosan hydrogel loaded with TGF-beta 3 can promote the repair of meniscus defects in rabbits.

Key words: chitosan composite hydrogel, transforming growth factor beta 3, meniscus defect, type Ⅱ collagen, proteoglycan