BMP-7衍生多肽/壳聚糖/纳米羟基磷灰石/胶原复合材料促进骨再生的实验研究

Experimental study on advanced bone regeneration by BMP-7 derived-peptide chitosan nanometer hydroxyapatite collagen biomimetic composite

目的探索新型仿生支架材料BMP-7衍生多肽/壳聚糖/纳米羟基磷灰石/胶原促进大鼠颅骨缺损再生的效果。方法制备复合支架材料壳聚糖/纳米羟基磷灰石/胶原,扫描电镜观察其表面微观形貌。将BMP-7衍生多肽与材料复合,高效液相色谱仪检测其在体外的释放规律。成年SD大鼠24只,在大鼠顶骨左、右两侧分别制备颅骨极限缺损,右侧设为实验组,植入BMP-7衍生多肽/壳聚糖/纳米羟基磷灰石/胶原复合材料,左侧设为对照组,植入单纯壳聚糖/纳米羟基磷灰石/胶原复合材料,于6周和12周时间点将大鼠分批处死,进行大体观察、CT三维重建和组织学观察。结果扫描电镜结果显示:支架材料呈多孔状;多肽体外释放实验结果表明BMP-7衍生多肽可以从材料中缓慢释出;大鼠颅骨缺损修复实验结果显示:在各时间点,复合BMP-7衍生多肽的壳聚糖/纳米羟基磷灰石/胶原支架材料与单纯壳聚糖/纳米羟基磷灰石/胶原支架材料相比,能够明显促进大鼠颅骨缺损修复,差异有显著性(P<0.05)。结论新型仿生支架材料BMP-7衍生多肽/壳聚糖/纳米羟基磷灰石/胶原能够有效促进骨再生,是一种具有良好应用前景的骨组织工程支架材料。

[ Objective ] To investigate the effect of BMP-7 derived-peptide chitosan nanometer hydroxyapatite biomimetic collagen composite on repairing rat critical-sized cranial defects. [Methods] The chitosan nanometer hydroxyapatite collagen composite was prepared and the microcosmic appearance of the composite was observed by scanning electron microscope. The BMP-7 derived-peptide was introduced into the composite by vacuum adsorption. The released peptide content from the scaffold was detected using high performance liquid chromatography at different set times. Critical-sized cranial defects were created on both sides of the parietal bone in 24 adult Sprague-Daw- Icy rats. The BMP-7 derived-peptide chitosan nanometer hydroxyapatite biomimetic collagen composites were implanted on the right side as experimental group and the left side was implanted with chitosan nanometer hydroxyap- atite biomimetic collagen composites alone as control group. The rats of both groups were killed in batch respectively after the 6 and 12 weeks. Macroscopic observation, three-dimensional reconstruction of computed tomography and histological observation were performed on these samples. [Results] The results of scanning electron microscope showed that the surface of the scaffold was porous. The releasing character of BMP-7 derived-peptide belonged to slow release. The result of animal experiment showed that the BMP-7 derived-peptide chitosan nanometer hydroxya- patite biomimetic collagen composite can more effectively promote the repair of cranial bone defects comparing with the chitosan nanometer hydroxyapatite biomimetic collagen composite alone. The difference was statistically significant （P 〈0.05）. [ Conclusions ] The BMP-7 derived-peptide chitosan nanometer hydroxyapatite collagen biomimetic composite can effectively promote bone regeneration of bone defects. The composite is a kind of ideal scaffold material for bone tissue engineering.