个体化假体复合组织工程技术修复兔下颌骨缺损

An experimental study of rabbit mandibular defect reconstruction with individualized prosthesis and tissue engineering

目的研究快速成型(RP)技术辅助下制作的个体化假体复合珊瑚羟基磷灰石(CHA)、重组人骨形成蛋白2(rhBMP⁃2)修复兔下颌骨缺损的成骨效果。方法以27只新西兰大白兔为实验对象,随机数字表法平均分成3组(每组9只),全部建立下颌骨连续性缺损模型,并在兔下颌骨缺损区分别植入个体化假体+自体骨(A组)、个体化假体+CHA(B组)、个体化假体+CHA+rhBMP⁃2(C组)。分别于术后4、12、24周3个时间点处死动物取材,进行大体标本观察,以及骨钙素(OC)、Ⅰ型胶原(COL⁃1)的免疫组化观察,分别比较各组修复骨缺损的能力,并对实验数据进行重复测量设计资料的单因素方差分析。结果术后24周各组实验兔外形均对称,通过OC及COL⁃1的吸光度检测,骨缺损区均有大量新骨形成,A组(0.537±0.010)、C组(0.530±0.010)可见大量骨小梁及编织骨结构,缺损区的新骨OC、COL⁃1的免疫组化观察基本一致,差异无统计学意义(t=0.007,P>0.05);但A组强于B组(0.415±0.009,t=0.122,P<0.001);C组也强于B组(t=0.121,P<0.001),差异均有统计学意义。结论在兔下颌骨缺损修复中,通过RP技术和组织工程技术相结合,CHA复合rhBMP⁃2后成骨能力明显增强,成骨效能肯定,为后期的临床应用提供可靠的实验基础。

Objective To evaluate the effect of individualized prosthesis combined with coralline hydroxyapatite(CHA)and recombinant human bone morphogenetic protein⁃2(rhBMP⁃2)on the reconstruction of rabbit mandibular defect with the aid of rapid prototyping(RP).Methods The radial defect models were made in 27 rabbits,which were evenly divided into 3 groups randomly.Individualized prostheses were obtained with RP.The 3 groups were treated with different materials:group A,individualized prostheses with autogenous bone;group B,individualized prostheses with CHA;group C,individualized prostheses with CHA and rhBMP⁃2.The measurement of bone mineral density(BMD)and the detection of osteocalcin(OC)and collagenⅠ(COL⁃1)with immunohistochemical staining were performed in 4,12,and 24 weeks after the operation so as to compare the capacity of bone reconstruction among the three groups.Data were analyzed with One⁃Way ANOVA.Results Both group A(0.537±0.010)and group C(0.530±0.010)showed a large number of trabecular and woven bone,whereas the contents of OC and COL⁃1 in the defect area were similar(t=0.007,P>0.05),both of which were significantly higher than group B(0.415±0.009)(tAB=0.122,PAB<0.001;tAB=0.121,PAB<0.001).Conclusions Upon the individualized three⁃dimensional titanium with RP,CHA combined with rhBMP⁃2 was found to have an improved osteoinductive ability,leading to a satisfactory recovery in both the contour and function of rabbit mandibles,which provided a reliable basis for individualized functional reconstruction of mandibular defects.