重组人骨形态形成蛋白-2胶原膜复合物对大鼠顶骨矢状缝快速牵张后复发的影响

Effects of rhBMP-2 collagen composite on relapse of rat interparietal suture after rapid expansion

目的 探讨基因重组人骨形成蛋白 2[rhBMP(bone morphogenetic protein) 2]胶原膜复合物对大鼠顶骨矢状缝经快速牵张力作用后复发回弹的影响。方法 10周龄SD雄性大鼠 32 只,随机分为自然生长组,单纯牵张组,牵张+胶原膜置入组,牵张+ rhBMP 2 胶原膜复合物置入共 4 组,每组 8只。建立大鼠顶骨矢状缝牵张模型,在实验第0天、第21天及第28天测量大鼠左右顶骨骨孔间的距离,比较计算牵张后复发率; 同时,用双能X线骨密度仪(dual X ray absorptiometry, DEXA)测量大鼠顶骨矢状缝的骨密度. 结果 ⑴加力第21天和第28天时各加力组左右顶骨两骨孔间的距离比空白对照组大( P<0.01)。在第21天时, 各加力组间的距离无差异 (P>0.05),但在第28天时rhBMP 2胶原膜复合物组较其余两组大(成P<0.05)。⑵各加力组间的扩张后复发率有明显差别,单纯牵张组、胶原膜组及 rhBMP 2 胶原膜复合物组的牵张后复发率分别为(53.25±8.80) %、(51.98±5.55) %、(2. 50±0.71) %。(3) 自然生长组在3个时间点的骨密度无明显变化(P>0.05);,rhBMP 2胶原膜复合物组骨密度在第21天时较第0天增加(P<0.01),第28天时进一步增加。其余两组在第21天时降低,第28天时稍有增加,但均比第0天时低(P<0.05)。结论 DEXA能对大鼠顶骨矢状缝新骨形成过程做测?

Objective To observe the relapse ratio of interparietal s agittal suture after removing the expansion device in rats. Methods 32 10-week old SD rats were divided into 4 groups, 8 rats each. They were one normal control group, one expansion control group, and two other group s that were covered with atelo-typeⅠcollagen and recombinant human bone morpho genetic protein (rhBMP)-2 collagen composite on the suture before subjected to the expansion force. The distance between the two holes of the interparietal sut ure bone was calculated on days 0, 21 and 28, then the relapse ratio was evaluat ed. At the same time the bone mineral density of the sagittal suture was also me asured with the dual X-ray absorptiometry (DEXA). Results There were no significant difference among the distance between the two holes in the expanded groups (P>0.05), but the distance of the expanded groups we re bigger than that of the normal control group on the 21st day. The distance of rhBMP-2 collagen composite group was the biggest among the expanded group on da y 28 ( P<0.05) , the distance of all three expanded groups were still big ger than that of normal control group (P<0.01). The relapse ratio was (53.2 5±8.80) %, (51.98±5.55) %, and (2.50±0.71) % in the expansion group, pure c ollagen membrane group and rhBMP-2 collagen composite groups, respectively. Th ere was a significant difference among the rhBMP-2/collagen composite group and the other two groups (P<0.01). We failed to find any difference of the bo ne mineral density (BMD) in the normal control group among the three time points (P>0.05). The BMD decreased on the 21st day although there was slightly in crease on day 28, but the BMD was still less than that of day 0 both in the expa nsion control group and the pure collagen membrane group. The BMD in the rhBMP- 2 collagen composite group increased on the 21st day and was higher than that of day 0 (P< 0.01 ), on the 28th day, the BMD got an sustained increase .Conclusion The DEXA can be used to measure the regenerative bo ne quantitatively during suture expansion and to monitor the process of bone reg eneration. RhBMP-2 collagen composite may be of therapeutic benefit in decreas ing relapse ratio after suture expansion.