OBJECTIVETo investigate the effect of rabbit bone marrow mesenchymal stem cells (MSCs) as seed cells for the repair of tendon defect.

METHODSThe MSCs were isolated, amplified and identified by detection of surface protein CD44 mRNA. A 3 cm long defect was made in the Achilles tendon of the rabbit. The rabbits were divided into experimental (E) and control (C) groups. The autologous MSCs were implanted into a collagen-polyglycolic acid (PGA) scaffold to form a tissue-engineered tendon, which was then transplanted to bridge the defect in the E group, while only collagen-PGA was transplanted to bridge the defect in the C group. The transplanted tendon was observed grossly and microscopically at 4, 8, 12 weeks after operation.

RESULTSThe cultured MSCs exhibited positive staining of CD44 on 11 days after in vitro culture. A tendon-like tissue could be discerned at the operation site in the E group 4 weeks after operation. Tendon-like cells similar to normal tendon tissue, being axially arranged in collagen matching the mechanical direction, with uniform morphology could be seen in E group 12 weeks after operation. The newly regenerated tissue in C group adhered to the adjacent tissue and was smaller than that in E group. The collagen fibers in the regenerated tissue were loose with reticular and filiform structure, and the cells were arranged disorderly 12 weeks after the transplantation.

CONCLUSIONIt is feasible to repair the tendon defect with autologous MSCs as seed cells.