聚乳酸-羟基乙酸／磷酸三钙人工支架修复退变椎间盘

Experimental study of polylactic acid - glycolic acid/tricalcium phosphate scaffold repairing the degenerative intervertebral disc

目的探讨胶原修饰改性聚乳酸-羟基乙酸／磷酸三钙（PLGA／TCP）人工支架联合人脐带间充质干细胞（hUC-MSCs）修复兔退变椎间盘的效果。方法人工建立兔腰椎间盘退变模型，以胶原修饰改性PLGA／TCP人工支架联合hUC-MSCs植人为实验组，单纯人工支架植入为对照组，空白组不予修复处理，术后2、4、8、12周进行兔腰椎间盘影像学检查，术后12周进行病理学检查。结果测量及计算椎间盘高度变化和椎间隙变化，结果发现12周实验组的椎间盘高度变化布拉德纳指数（BDI）（0．063±0．011）显著低于对照组（0．039±0．006，P=0．014）和空白组（0．033±0．006，P=0．010），实验组的椎间盘高度指数（DHI）（87．6±10．4）显著轻于对照组（66．8±9．2，P=0．028）和空白组（46．7±7．3，P=0．001）。MRI检测结果可见术后12周实验组12值变化比值（0．760±0．078）较对照组（0．600±0．071，P=0．033）与空白组（0．540±0．093，P=0．015）小，差异有统计学意义。免疫组织化学实验结果显示实验组Ⅱ型胶原含量（151．7±10．3）显著高于对照组（125．8±9．6，P=0．023）和空白组（118．2±6．1，P=0．017）。结论胶原改性聚乳酸一羟基乙酸／磷酸三钙PLGA／TCP人工支架联合人脐带间充质干细胞hUC-MSCs能有效促进退变椎问盘修复，可以作为未来临床修复椎间盘退变的生物学方法。

Objective To investigate the effect of collagen modified polylactic acid - glycolic acid/tricalcium phosphate （PLGA/TCP） scaffold combined with human umbilical cord mesenchymal stem ceils （hUC- MSCs） to repair the rabbit intervertebral disc degeneration in vivo. Methods The rabbit model of degenerative intervertebral disc was built. Using collagen modified PLGA/TCP scaffold combined with hUC - MSCs implantation for the experimental group, scaffold implantation alone for the control group, and no repairs for the blank group. Rabbit lumbar disc imaging examination was performed 2, 4, 8 and 12 weeks after operation, and histological examination was implemented 12 weeks after surgery. Results Measurement of intervertebral disc height and inteIvertebral space changes found that vertebral degeneration were significantly lower in the experimental group （ Brander disc index BDI 0. 063 ± 0. 011, disc height in- dex DHI 87. 6 ± 10.4） when compared to the control group （ BDI 0. 039 ±0. 006, P = 0. 014） （ DHI 66. 8 ± 9. 2, P = 0. 028） and the blank group （ BDI 0. 033 ± 0. 006, P = 0. 010） （ DHI 46. 7 ± 7.3, P = 0. 001 ）. The MRI results showed that the change of T2 value of experimental group （0. 760±0. 078） was significantly smaller that of the control group （0. 600 ±0. 071, P =0. 033） and the blank group （0. 540 ± 0. 093, P = 0. 015）. Immunohistochemistry results showed that type II collagen of intervertebral disc tissue in the experimental group （ 151.7 ± 10. 3） was more than the control group （ 125.8 ±9. 6, P = 0. 023 ） and the blank group （ 118. 2±6. 1, P = 0. 017）, and the difference is of significance. Conclusion Collagen modified PLGA/TCP scaffold combined with hUC - MSCs can significantly promote degenerative disc re- pair, which can be used as a biological method to repair disc degeneration in the future.