Yan Jihong, Yang Shu, Sun Huaimei, Guo Duo, Wu Bo, Ji Fengqing, Zhou Deshan
Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, China.
Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, China
J Biomater Appl. 2014 Jul;29(1):72-80. doi: 10.1177/0885328213515034. Epub 2013 Dec 10.
The objective of this study was to investigate the therapeutic potential of poly(lactic-co-glycolic acid) (PLGA) microspheres loaded with recombinant human growth and differentiation factor-5 (rhGDF-5) on the disc degeneration induced by needle puncture in a rat caudal disc model.
The rhGDF-5-loaded PLGA microspheres were prepared by the water-oil-water double-emulsion solvent evaporation method, and release kinetics was determined over 42 days. Rats that underwent 21-G needle puncture at rat tail discs were injected with rhGDF-5/PLGA microspheres at four weeks after needle injury. At eight weeks after the injection, disc height, glycosaminoglycans content, and DNA content of the discs were evaluated. In addition, gene expression analysis of aggrecan, collagen type I, and collagen type II in the rat nucleus pulposus was measured by real-time polymerase chain reaction. Rat discs were also assessed by histology using hematoxylin and eosin stain.
Encapsulation of rhGDF-5 in PLGA microspheres guaranteed a sustained release of active rhGDF-5 for more than 42 days. The injection of GDF-5/PLGA microspheres resulted in a statistically significant restoration of disc height (p < 0.01), improvement of sulfated glycosaminoglycan (p < 0.05), DNA content (p < 0.05), and significantly increased mRNA levels of collagen type II (p < 0.01), and the differentiation index (the ratio of collagen type II to collagen type I, p < 0.01). In addition, rhGDF-5/PLGA microspheres treatment also improved histological changes induced by needle puncture.
The results of this study suggest that injection of rhGDF-5 loaded in PLGA microspheres into rat tail discs may be as a promising therapy strategy to regenerate or repair the degenerative disc.
本研究的目的是在大鼠尾椎间盘模型中，研究负载重组人生长分化因子-5（rhGDF-5）的聚乳酸-乙醇酸共聚物（PLGA）微球对针刺诱导的椎间盘退变的治疗潜力。
采用水-油-水双乳液溶剂蒸发法制备负载rhGDF-5的PLGA微球，并测定其42天的释放动力学。在大鼠尾椎间盘进行21G针刺的大鼠在针刺损伤后四周注射rhGDF-5/PLGA微球。注射后八周，评估椎间盘的高度、糖胺聚糖含量和DNA含量。此外，通过实时聚合酶链反应测量大鼠髓核中聚集蛋白聚糖、I型胶原和II型胶原的基因表达分析。还使用苏木精和伊红染色通过组织学评估大鼠椎间盘。
rhGDF-5包裹在PLGA微球中可保证活性rhGDF-5持续释放超过42天。注射GDF-5/PLGA微球导致椎间盘高度有统计学意义的恢复（p<0.01），硫酸化糖胺聚糖改善（p<0.05），DNA含量改善（p<0.05），II型胶原mRNA水平显著增加（p<0.01），以及分化指数（II型胶原与I型胶原的比率，p<0.01）显著增加。此外，rhGDF-5/PLGA微球治疗还改善了针刺引起的组织学变化。
本研究结果表明，将负载rhGDF-5的PLGA微球注射到大鼠尾椎间盘中可能是一种有前景的治疗策略，用于再生或修复退变的椎间盘。
