应用水溶性壳聚糖为主要载体的重组人骨形态发生蛋白2缓释系统:降解缓释和成骨作用评价

Degradable release and osteogenesis of recombinant human bone morphogenetic protein 2 system with water-soluble chitosan

目的:将水溶性壳聚糖为主要载体的重组人骨形态发生蛋白2缓释系统用于下颌骨缺损的修复,评价其降解缓释特性和诱导成骨作用。方法:实验于2006-06/10在兰州大学动物实验中心完成。①实验分组:普通级家兔24只,体质量2.5～2.7kg,随机数字表法分为实验组(n=16),对照组(n=8)。②实验方法:将复方骨形态发生蛋白生物黏附膜制备成试样1(复合材料,重组人骨形态发生蛋白/壳聚糖),其中含重组人骨形态发生蛋白2100μg;将单纯壳聚糖经同法制成试样2(单纯壳聚糖),并将其用于兔两侧下颌骨缺损动物模型的骨缺损修复。实验组分别于右侧骨缺损处置入试样1,左侧骨缺损处置入试样2;对照组则造成两侧下颌骨缺损后未置入任何材料。③实验评估:分别于第2,4,8,12周分批麻醉后处死动物,取下标本作大体观察、X线片、常规组织学检查,分别采用Motic Images Advanced3.0和Freemax图像分析处理软件计算骨矿化沉积速度以及组织学成骨面积定量分析。结果:纳入家兔24只,均进入结果分析。①实验期间各组实验位点均未发生炎症和排异反应,各组创口愈合均良好,成骨活跃。②4,8,12周时试样1组的骨矿化沉积速度分别为1.91,1.5,1.12μm/d,明显优于对照组(P<0.05),4周时试样1组成骨量最多,其余两组成骨量差异不大;12周时试样2组与试样1组相比,成骨量的差异无显著性意义。但是试样2组也存在一定的成骨活性。结论:复方骨形态发生蛋白生物黏附膜呈现良好的生物相容性和骨引导性,复合骨形态发生蛋白后早期通过骨形态发生蛋白的骨诱导作用对骨再生具有较明显的促进作用。其修复颌骨缺损具有较好的效果和临床应用前景。

AIM： To evaluate the degradable release and inducing osteogenesis of recombinant human bone morphogenetic protein （BMP） 2 system with water-soluble chitosan in the reconstruction of mandibular defects. METHODS： The experiment was carried out in the Animal Experimental Center of Lanzhou University from June to October in 2006①A total of 24 common rabbit aged 2.5-2.7 kg were randomly divided into experimental group （n =16） and control group （n =8）. ②The right mandibular defects of rabbits were repaired by implanting chitosan combined with compound BMP containing 2 100 μg BMP-2 as sample 1, while the left defects were implanted with single chitosan carrier as sample 2. No materials were given in the Control group ③At weeks 2, 4, 8, 12 after implantation, the rabbits were anesthetized to death in batch. The mandibular samples were examined by X-ray and routine histological observation. Bone mineralization apposition rate and ossifying area quantitative analysis were performed using Motic Images Advanced 3.0 and Freemax image analyzer. RESULTS： All of 24 rabbits were involved in the result analysis.①No inflammation or rejection response was detectable during the experiment, and the wound healed well with the bone regenerated actively. ②At weeks 4, 8 and 12 postoperatively, mineral apposition rates of experimental 1 group were 1.91, 1.5 and 1.12 μm/d respectively, which were remarkably higher than that of control group （P 〈 0.05）. The new bone mass in experiment 1 group at week 4 was the most, and there was no statistically significant difference between the other two groups. At week 12, no significant difference was found between experimental 1 group and experimental 2 group with regard to the bone regeneration. But experimental 2 group also presented osteogenesis activity. CONCLUSION： The compound BMP bioadhesive film possesses sound biocompatibility and osteoconductivity, and will obviously promote the bone regeneration if combined with BMP. This new biomaterial is potential to obtain good effect and clinical erosprospect in the reconstruction of mandibular defects.