Comparative Study on Functional Effects of Allotransplantation of Bone Marrow Stromal Cells and Adipose Derived Stromal Vascular Fraction on Tendon Repair: A Biomechanical Study in Rabbits

Objective: tendon never returns to its complete biological and mechanical propertiesafter repair. bone marrow and, recently, adipose tissue have been used as sources ofmesenchymal stem cells which have been proven to enhance tendon healing. in thepresent study, we compared the effects of allotransplantation of bone marrow derivedmesenchymal stromal cells (bmscs) and adipose derived stromal vascular fraction(svf) on tendon mechanical properties after experimentally induced flexor tendontransection.materials and methods: in this experimental study, we used 48 adult male new zealandwhite rabbits. twelve of rabbits were used as donors of bone marrow and adipose tissue,the rest were divided into control and treatment groups. the injury model was a unilateralcomplete transection of the deep digital flexor tendon. immediately after suture repair,4×106 cells of either fresh svf from enzymatic digestion of adipose tissue or culturedbmscs were intratendinously injected into tendon stumps in the treatment groups. controlsreceived phosphate-buffered saline (pbs). immobilization with a cast was continuedfor two weeks after surgery. animals were sacrificed three and eight weeks after surgeryand tendons underwent mechanical evaluations. the differences among the groups wereanalyzed using the analysis of variance (anova) test followed by tukey’s multiple comparisonstest.results: stromal cell transplantation resulted in a significant increase in ultimate andyield loads, energy absorption, and stress of repairs compared to the controls. however,there were no statistically significant changes detected in terms of stiffness. in comparison,we observed no significant differences at the third week between svf and bmscstreated tendons in terms of all load related properties. however, at the eighth week svftransplantation resulted in significantly increased energy absorption, stress and stiffnesscompared to bmscs.conclusion: the enhanced biomechanical properties of repairs in this study advocatesthe application of adipose derived svf as an excellent source of multipotent cells insteadof traditional bmscs and may seem more encouraging in cell-based therapy for tendoninjuries.