明胶-壳聚糖-羟基磷灰石-米诺环素仿生纳米复合材料修复桡骨缺损

Gelatin-chitosan-hydroxyapatite-minocycline biomimetic nanocomposite materials for repair of rabbit radius defects

背景:课题组前期研制了新型明胶-壳聚糖-羟基磷灰石-米诺环素仿生纳米复合材料。目的:观察明胶-壳聚糖-羟基磷灰石-米诺环素仿生纳米复合材料修复兔桡骨缺损的效果。方法:取30只成年健康新西兰大白兔,在一侧桡骨上端制作约15 mm×6 mm的临界性腔隙性骨缺损,随机分为实验组(n=15)、自体骨移植组(n=10)和空白对照组(n=5),实验组将明胶-壳聚糖-羟基磷灰石-米诺环素仿生纳米复合材料植入骨缺损处,自体骨移植组从对侧桡骨取等长桡骨植入骨缺损处,空白对照组不做任何处理。于术后2,4,8,12周分别行大体观察、组织学观察及X射线平片检查。结果与结论:植入后12周,实验组骨缺损区有明显血管生成,骨性愈合完全,植入复合材料消失,出现板层骨结构,可见小血管,新生骨边缘与原骨边缘连接,表现成骨的连续性,密度较原骨稍降低,骨缺损区不明显;自体骨移植组骨性愈合,骨小梁重建较明显,板层骨较成熟,髓腔再通,骨折线完全消失,骨密度与原骨完全一致;空白对照组髓腔无明显成骨现象,大量纤维组织及炎症细胞浸润,骨折断端未愈合。表明明胶-壳聚糖-羟基磷灰石-米诺环素仿生纳米复合材料可明显促进临界性骨缺损修复,效果与自体骨移植相当。

BACKGROUND：Gelatin-chitosan-hydroxyapatite-minocycline biomimetic nanocomposite materials were developed in our previous studies. OBJECTIVE：To observe the capability of gelatin-chitosan-hydroxyapatite-minocycline biomimetic nanocomposite materials in the repair of rabbit radius defects. METHODS： Thirty healthy adult New Zealand rabbits were selected to make critical-size lacunar bone defects of the upper radius （15 mm×6 mm）. Then, the rabbit models were randomized into experimental group （n=15）, autogenous bone graft group （n=10） and blank group （n=5）. Gelatin-chitosan-hydroxyapatite-minocycline biomimetic nanocomposite materials were implanted into radial bone defects in the experimental group. Bone defect in blank group was implanted without any materials; in the autogenous bone graft group, the contralateral radius with same length was taken and implanted into the defect. General observation, histological observation and X-ray observation were performed respectively at 2, 4, 8, 12 weeks postoperatively. RESULTS AND CONCLUSION：At 12 weeks after operation, the experimental group showed obvious new blood vessels at the defect region, complete bony union and disappearance of the composite implant, but lamelar bone structure appeared, smal blood vessels were visible, the edge of new bone was connected to the original bone edge, exhibiting a continuity of bone, the bone density was slightly lowered, and the defect region became unobvious. In the autogenous bone graft group, bony union and trabecular bone reconstruction were distinct, the lamelar bone became mature, the medulary cavity was recanalized, the fracture line disappeared completely, and the bone density was completely consistent with that of the original bone. In the blank group, there was no obvious bone formation, which led to bone nonunion, and there were a great amount of fiber tissues and inflammatory cel infiltrated. To sum up, the gelatin-chitosan-hydroxyapatite-minocycline biomimetic nanocomposite material can obviously promote the repair of critical-size bone defects, and the repairing effect is basicaly the same with that of autologous bone grafting.