The Effects Of Tendon-derived Stem Cell Sheet In Tendon-bone Healing

Objective Tendon-bone healing is a slow process after anterior cruciate ligament(ACL)reconstruction.The promoting of tendon-bone healing could improve knee pain and dysfunction.In this study,we investigated the role of tendon-derived stem cells(TDSCs)sheet in tendon-bone healing in an extra-articular bone tunnel rat model.Methods The TDSCs sheet was wrapped around the superficial flexor tendon to form the complex of cell sheet and tendon as experimental group,simple superficial flexor tendon as control group.Both of them was transplanted into 1.0-mm diameter bone tunnel of proximal tibia,At week 2,4,8 after reconstruction,the bone-graft-bone complex were obtained and measured by radiology,histology,biomechanics.Results Radiology showed TDSCs sheet significantly enhanced tendon-bone healing as indicated by higher tunnel bone mineral density(BMD)and bone volume/total volume(BV/TV)at week 4 after operation.Hematoxylin-eosin(HE)staining revealed that TDSCs sheet enhanced the perpendicular collagen fibers connecting the tendon to the bone,sharpey's fibers,and new bone formation in the tendon-bone junction at week 4 and 8 histologically;Masson staining showed the tendon-bone interface was filled with abundant collagen fibers,and the proportion of collagen fiber area was significantly higher in TDSCs sheet group than the control group at week 4 and 8.The ultimate load and healing strength of bone-graft-bone complex were significantly greater in the TDSCs sheet group compared to those in the control group.Conclusion TDSCs sheet could promotes tendon-bone healing in the early stage,which might provide a new feasible therapeutic strategy to accelerate early remodeling of tendon-bone healing.