Wijdicks Coen A, Virdi Amarjit S, Sena Kotaro, Sumner Dale R, Leven Robert M
Department of Anatomy and Cell Biology, Rush University Medical Center, Chicago, IL 60612, USA.
Ultrasound Med Biol. 2009 Oct;35(10):1629-37. doi: 10.1016/j.ultrasmedbio.2009.04.017. Epub 2009 Jul 25.
Two methods to improve bone repair include the use of recombinant human bone morphogenetic protein-2 (rhBMP-2) and low-intensity pulsed ultrasound (LIPUS). The present study was designed to determine if LIPUS enhances the effect of rhBMP-2-induced bone formation in a well characterized ectopic implant model. Absorbable collagen sponges loaded with 0-, 1-, 2.5- or 5-microg doses of rhBMP-2 were implanted subcutaneously in 11-week-old, male Long Evans rats, followed by daily 20-min LIPUS or sham LIPUS treatment beginning 1 d after surgery. Explanted sponges were assessed for bone volume, mineral density and mineral content by microcomputed tomography (microCT). At two weeks, LIPUS had no effect on rhBMP-2-induced bone formation, but at four weeks, LIPUS increased bone volume in the 1-microg rhBMP-2-treated implants 117.7-fold (0.02 +/- 0.04 mm(3)vs. 2.07(S.E.M.) +/- 1.67 mm(3);p = 0.028), and 2.3-fold in the 5-microg dose implants (5.96 +/- 3.68 mm(3)vs. 13.52 +/- 6.81 mm(3);p = 0.077) compared with sham LIPUS. Bone mineral density was not affected by LIPUS treatment. Total mineral content followed the same pattern as bone volume. Histologic staining for mineralized tissue was consistent with the microCT observations. The present study is the first to demonstrate that LIPUS enhances bone formation induced by rhBMP-2.
两种改善骨修复的方法包括使用重组人骨形态发生蛋白-2（rhBMP-2）和低强度脉冲超声（LIPUS）。本研究旨在确定在一个特征明确的异位植入模型中，LIPUS是否能增强rhBMP-2诱导的骨形成效果。将负载0、1、2.5或5微克剂量rhBMP-2的可吸收胶原海绵皮下植入11周龄的雄性Long Evans大鼠体内，术后1天开始每天进行20分钟的LIPUS或假LIPUS治疗。通过微型计算机断层扫描（microCT）评估取出的海绵的骨体积、矿物质密度和矿物质含量。在两周时，LIPUS对rhBMP-2诱导的骨形成没有影响，但在四周时，与假LIPUS相比，LIPUS使1微克rhBMP-2处理的植入物中的骨体积增加了117.7倍（0.02±0.04立方毫米对2.07（标准误）±1.67立方毫米；p = 0.028），在5微克剂量的植入物中增加了2.3倍（5.96±3.68立方毫米对13.52±6.81立方毫米；p = 0.077）。LIPUS治疗对骨矿物质密度没有影响。总矿物质含量与骨体积的变化模式相同。矿化组织的组织学染色与microCT观察结果一致。本研究首次证明LIPUS可增强rhBMP-2诱导的骨形成。
