PDLLA和PDLLA/TCP复合物修复下颌骨缺损过程中TGF-β1的表达

The expression of TGF-β1 in the tissues around mandibular defect that repaired by PDLLA or PDLLA/TCP composite

目的:检测混旋聚乳酸(PDLLA)及PDLLA/磷酸三钙(TCP)复合物植入骨缺损模型后,不同时期TGF-β1的表达特点,探讨PDLLA及PDLLA/TCP复合物对骨缺损修复的影响。方法:在60只大鼠一侧下颌骨体部形成下颌骨缺损模型,并随机分为三组,每组20只。分别为PDLLA组,PDLLA/TCP组及空白对照组。术后第2、8、16周分批处死各组大鼠,取下颌骨采用免疫组织化学方法观察缺损区域TGF-β1的表达特点。结果:3组动物均能在术后2周在缺损区附近组织检测到TGF-β1的高水平表达,PDLLA组及PDLLA/TCP组阳性表达一直持续到8周以后,16周时仍能检测到弱阳性表达,空白对照组表达强度减弱较快,8周后基本呈阴性表达。结论:下颌骨缺损植入PDLLA/TCP复合物或纯PDLLA后,缺损区附近组织TGF-β1呈持续阳性表达,表达位置与成骨活跃部位一致,提示有持续活跃的成骨现象,证实PDLLA及PDLLA/TCP复合物对下颌骨缺损修复有持续的诱导作用。

Objective： To observe the expression of TGF-β1 in the tissues around mandibular defect that repaired by PDLLA or PDLLA / TCP composite and estimate the effect of PDLLA or PDLLA / TCP composite on mandibular defect repair.Method： The model of mandibular defect were created in sixty Wistar rats. Twenty defects were filled with PDLLA / TCP composite： twenty were filled with pure PDLLA; the others were filled with nothing-as the control group. The immunohistochemistry of TGF-β1 were taken at the 2nd, 8th, 16th week after mandibular defect filled with PDLLA or its composite. Result：High expression level of TGF-β1 were observed in the tissues around defect in immunohistochemical study two weeks after operation in either test group or control group. However the strong expressions last 8 weeks and still can be found ＇after 16 weeks after operation in the test group. But the expressions descend very fast in the control group. Conclusion： The high expression level of TGF-β1 around defect showed lasting high activity of bone formation after mandibular deifect filled with PDLLA or its composite.