Mesenchymal stem cell application improves tendon healing via anti-apoptotic effect (Animal study).

OBJECTIVE: The aim of this study was to determine the effects of mesenchymal stem cell (MSC) application and the possible pathways of MSC's effects on tendon strength and healing after tendon repair.

METHODS: The study included 40 Wistar albino rats. Mesenchymal stem cells were obtained from the femurs and tibias of 6 rats. Achilles tendons of the remaining 34 rats were cut and repaired with open surgical procedures. Rats were divided into 2 groups. Percutaneous MSCs were applied to the study group (n=17) and physiological serum only was applied to the control group (n=17) at the 4th week. Rats were sacrificed using the cervical dislocation method under ether anesthesia at the 12th week and samples were analyzed by histological and immunohistochemical methods. For biomechanical analysis, a traction force was applied at 10 mm/min and load to failure was recorded for each specimen in Newtons.

RESULTS: Histologically, there was no significant difference between groups (p>0.05). In the immunohistochemical studies, MSCs were located more intensively at the repair zone. Apoptosis was minimally present in the study group and was clearly increased in the control group. Increase in tendon strength was significantly higher in the study group than in the control group at the 12th week (p<0.05).

CONCLUSION: The application of MSCs to decrease re-ruptures has a positive effect on tendon strength, probably due to their anti-apoptotic effects. Mesenchymal stem cell application can be used percutaneously and is effective in clinical practice in the late stages of tendon healing.