纳米羟基磷灰石/壳聚糖/海藻酸钠复合材料修复下颌骨缺损

Nano-hydroxyapatite/chitosan/alginate for repairing mandibular defects

背景:有研究证实,纳米羟基磷灰石/壳聚糖/海藻酸钠三元复合材料具有一定的柔韧性和强度,具有与人体骨相似的生物活性。目的:观察纳米羟基磷灰石/壳聚糖/海藻酸钠复合材料修复兔下颌骨缺损的效果。方法:在18只健康新西兰大白兔两侧下颌骨制作10 mm×5 mm×5 mm的缺损,随机分为2组,实验组双侧骨缺损处植入纳米羟基磷灰石/壳聚糖/海藻酸钠复合材料,对照组双侧骨缺损处植入纳米羟基磷灰石/壳聚糖,植入后4,8,12周,应用锥形束CT观察各组缺损区材料降解、骨痂生长及骨连接情况,苏木精-伊红染色观察新骨生成。结果与结论:两组骨密度灰度值均随着时间延长逐渐增加,组内不同时间点间差异有非常显著性意义(P<0.01);在相同时间点条件下,实验组大体观察、锥形束CT观察及CT灰度值,以及组织学观察均优于对照组(P<0.05)。在材料植入后第4-8周,两组植入材料均已逐渐降解,缺损区与骨组织相交接处模糊,有少量新骨生成,与受体骨组织结合紧密,其中以实验组较为明显;第8-12周,两组植入材料已经基本降解完全,与受体骨组织开始逐渐相融合,有新生骨组织进一步生成,骨缺损区域逐渐被修复,以实验组较为明显。结果表明纳米羟基磷灰石/壳聚糖/海藻酸钠可有效修复骨缺损,促进新骨生成。

BACKGROUND： Studies have confirmed that the nano-hydroxyapatite/chitosan/alginate composite materials have a certain flexibility and strength and possess a bioactivity similar to human bone. OBJECTIVE： To explore the effect of the nano-hydroxyapatite/chitosan/alginate composite materials on the repair of rabbit mandible defects. METHODS： Bilateral mandibular defect models of 10 mm x 5 mm x 5 mm were made in 18 healthy New.Zealand white rabbits. Then, the rabbits were divided into two groups： experimental group was implanted with nano-hydroxyapatitelchitosanlalginate composite material, and control group was implanted with hydroxyapatite/chitosan composite. At 4, 8 and 12 weeks after implantation, cone-beam CT was applied to observe implant degradation, callus growth and bone connection in the defect area; new bone formation was observed by hematoxylin-eosin staining. RESULTS AND CONCLUSION： The gray values of the bone density in the experimental group and control group gradually increased with time, and there were remarkably significant differences between the two groups at different time points （P 〈 0.01 ）. At the same time point, the experimental group was superior to the control group in gross observation, cone-beam CT observation, gray value of CT and histological observation （P 〈 0.05）. At4-8 weeks after implantation, the implant materials in the two groups were gradually degraded with a blurred junction between the defect and bone tissue, and a small amount of new bone formed tightly integrated to the recipient bone tissue, in which the experimental group was more significant. And during 8 to 12 weeks, the degradation of implanted materials in the two groups was basically complete, and the implant began to merge with the recipient bone tissue, with further generation of new bone tissue and gradual repair of bone defect area, in which, the experimental group was more obvious. Results show that the nano-hydroxyapatite/chitosan/alginate can repair bone defects effectively, and promote the new bone formation.