脂肪干细胞复合PLGA对骨质疏松骨折愈合后生物力学的影响

目的探讨骨质疏松骨折后脂肪干细胞(ADSCs)复合聚乳酸共聚物(PLGA)对骨折愈合后生物力学的影响。方法建立大鼠骨质疏松骨折模型,将成功建立模型的27只大鼠分为治疗组(n=18)和空白对照组(n=9),治疗组大鼠的右侧股骨骨折肢为脂肪干细胞复合PLGA治疗组(ADSCs/PLGA组),左侧为单纯脂肪干细胞组(ADSCs组),于治疗后2、4、8周分别处死大鼠,取股骨测量新生骨痂的横截面积及相关生物力学指标。结果骨折后2周,与空白对照组和ADSCs组比较,ADSCs/PLGA组骨痂横截面积最大,空白组最小,各组间两两比较差异有统计学意义(P<0.05),骨折后4周各组间骨痂横截面积比较差异无统计学意义。各组剪切强度、弹性模量随着时间的推移,逐渐升高,各时间点均以ADSCs/PLGA组测定值最高,空白组最低,各组间比较差异均有统计学意义(P<0.01);剪切应变随着时间推移,逐渐降低,各时间点均是ADSCs/PLGA组测定值最低,空白组最高,各组间比较差异均有统计学意义(P<0.01)。最大载荷测定值在各时间点各组间比较为ADSCs/PLGA组最高,空白组最低,各组间比较差异均有统计学意义(P<0.01)。骨折后4、8周,最大应力测定值ADSCs/PLGA组最高,空白组最低,各组之间比较差异有统计学意义(P<0.01)。结论脂肪干细胞复合PLGA可以提高骨质疏松骨折后骨质愈合的质量,为临床骨质疏松骨折的治疗提供实验依据。

Effect of Adipose Derived Stem Cells in PLGA on Biomechanics after Osteoporotic Fracture-healing

Objective To explore effect of adipose derived stem cells(ADSCs) in PLGA on biomechanics after osteoporotic fracture-healing.Methods 27 osteoporotic fracture model were randomized into control group(n=9) and experiment group(n=18).Starting from day 1,the sites of fracture were given different injections: triple distilled water for control group,ADSCs for the left femur of experimental group.ADSCs/PLGA were implanted in the right femur of experimental group through cutting the subcutaneous tissue.According to different times,the size of new callus were measured while biomechanics indexes were detected.Results Callus formation of the right femur was the most obvious after 2 weeks.This difference disappeared after 4 weeks.With the development of time,shear strength and modulus of elasticity gradually increased,shear strain gradually decreased,especially at the right femur.Compared the maximum load and stress,results showed statistical significance.Conclusion Local implation of ADSCs/PLGA may promote quality of osteoporotic fracture healing,which can provide new method for clinical practice.