Department of Biological Sciences, Missouri University of Science and Technology, Rolla, Missouri.
Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, Missouri.
J Biomed Mater Res A. 2020 May;108(5):1231-1242. doi: 10.1002/jbm.a.36897. Epub 2020 Feb 24.
Our aims were to 1) evaluate the capacity of hollow hydroxyapatite (HA) microspheres (212-250 μm) to serve as a delivery system for controlled release of BMP-2 in vitro and 2) examine relaxin as an enhancer of BMP-2 for bone regeneration. Hollow HA microspheres were converted from borate glass microspheres and characterized using X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, and the Brunauer-Emmett-Teller method. The microspheres loaded with BMP-2 and relaxin were implanted for 6 weeks in Sprague Dawley rats with calvarial defects. BMP-2 alone in the range up to 1 μg per defect exhibited dose-dependent bone regeneration while relaxin alone in the range up to 0.25 μg per defect did not promote bone regeneration. When compared with BMP-2 alone (1 μg per defect), a 50% reduction in the BMP-2 dose was achieved with the addition of 0.05, 0.1, or 0.25 μg of relaxin per defect. These results show that loading HA microspheres with a combination of relaxin and BMP-2 can significantly reduce the BMP-2 dose required to regenerate an equivalent amount of bone.
1）评估中空羟磷灰石（HA）微球（212-250μm）作为体外控制释放 BMP-2 的输送系统的能力；2）研究松弛素作为增强 BMP-2 促进骨再生的作用。中空 HA 微球由硼酸盐玻璃微球转化而来，并通过 X 射线衍射、傅里叶变换红外光谱、扫描电子显微镜和 Brunauer-Emmett-Teller 方法进行了表征。将负载 BMP-2 和松弛素的微球植入 Sprague Dawley 大鼠颅骨缺损中 6 周。单独使用 BMP-2 时，每个缺损高达 1μg 的剂量范围内表现出剂量依赖性的骨再生，而单独使用松弛素时，每个缺损高达 0.25μg 的剂量范围内并未促进骨再生。与单独使用 BMP-2（每个缺损 1μg）相比，当每个缺损添加 0.05、0.1 或 0.25μg 的松弛素时，BMP-2 的剂量减少了 50%，可以实现相同量的骨再生。这些结果表明，将松弛素和 BMP-2 组合负载到 HA 微球中可以显著减少再生等量骨所需的 BMP-2 剂量。
