Objective: To evaluate the application of tendon-derived stem cells (TDSC) and bone marrow-derived mesenchymal stem cells (BMSC) for patellar tendon injury repair in rat model.
Methods: TDSCs and BMSCs were isolated from patellar tendons or bone marrow of healthy SD rats. The patellar tendon injury model was induced in 60 SD rats, then the animals were divided into 3 groups with 20 in each group: rats in TDSC group received transplantation of TDSC with fibrin glue in defected patellar tendon, rats in BMSC group received BMSC with fibrin glue for transplantation and those in control group received fibrin glue only. The gross morphology, histology and biomechanics of the patellar tendon were examined at 1, 2, 4, 6 and 8 weeks after the treatment.
Results: Gross observation showed that the tendon defects in TDSC group and BMSC group almost disappeared in week 8, while the boundary of tendon defects in control group was still visible. Histology examination showed that the neo-tendon formation in TDSC group and BMSC group was observed at week 8, while there was no neo-tendon formation in control group. Biomechanics study showed that the ultimate stress and Young Modulus, relative ultimate stress and relative Young Modulus increased with the time going in all groups(all P<0.05); the ultimate stress and Young Modulus, relative ultimate stress and relative Young Modulus of TDSC and BMSC groups were significantly higher than those in control group at week 4, 6 and 8(all P<0.05). There was no difference in ultimate stress and Young Modulus between TDSC group and BMSC group(P>0.05), however, the relative Young Modulus of TDSC group was significantly higher than that in BMSC group at week 8(P<0.05).
Conclusion: Allogeneic TDSC and BMSC transplantation facilitates the repair of tendon injury and improves the biomechanics of tendon. TDSC is more suitable for in vivo tendon regeneration than BMSC.
目的: 观察肌腱干细胞(TDSC)和骨髓间充质干细胞(BMSC)对大鼠缺损髌腱的修复作用。
方法: 从SD大鼠的髌腱及骨髓组织中,分离出TDSC和BMSC并培养,分别联合纤维蛋白胶移植到大鼠髌腱缺损模型中。60只SD大鼠分为以下三组:TDSC组采用TDSC＋纤维蛋白胶;BMSC组采用BMSC+纤维蛋白胶;对照组采用纤维蛋白胶。术后1、2、4、6、8周检测移植物的大体外观形态、组织学变化及生物力学指标。
结果: 术后8周TDSC组、BMSC组髌腱缺损基本消失,对照组仍可见髌腱缺损边界。术后8周TDSC组、BMSC组均可见类似肌腱样组织;对照组见肉芽组织增生,细胞排列紊乱,组织杂乱无序。随着时间增长各组的最大应力、最大应力百分比和弹性模量、弹性模量百分比均增加(均 P<0.05);在各个时间点,TDSC组、BMSC组的最大应力和弹性模量均高于对照组(均 P<0.05)。在2周时,TDSC组的最大应力百分比和弹性模量百分比均高于对照组(均 P<0.05);TDSC组、BMSC组在4、6、8周时最大应力百分比和弹性模量百分比均高于对照组(均 P<0.05),TDSC组与BMSC组差异无统计学意义( P>0.05)。8周时,TDSC组与BMSC组的弹性模量百分比差异有统计学意义( P<0.05)。
结论: 同种异体TDSC联合纤维蛋白胶可促进肌腱早期愈合、改善肌腱的生物力学特性,并且其弹性模量优于BMSC联合纤维蛋白胶,提示TDSC能更好地促进肌腱损伤的早期修复。