Department of Biomedical Engineering, The University of Texas at San Antonio, San Antonio, Texas, USA.
J Biomed Mater Res A. 2012 Nov;100(11):3117-23. doi: 10.1002/jbm.a.34241. Epub 2012 Jul 20.
The goal of this study was to determine the effectiveness of using polyethyleneimine (PEI) and a polyethylene glycol (PEG) tether to bind human recombinant bone morphogenetic protein-2 (rhBMP-2) to hydroxyapatite (HAp) to enhance rhBMP-2 loading, alter its release properties, and enhance cellular interaction with the material. By using a branched PEI that was derived to express free thiols, rhBMP-2 was coated onto dense HAp surfaces at ~43 ng/cm(2). Using this novel attachment methodology, it was observed that the PEI-SH coating did not change the morphology of the HAp surfaces and that the amount of rhBMP-2 loaded was comparable to a direct adsorption method. In addition, it was also observed that the PEI and PEG tether significantly retained the rhBMP-2 to the HAp surface, inhibiting the burst release effect. Using human fetal osteoblast cells, the PEI- and PEG-tethered BMP-2 was also observed to increase cellular attachment by 10-fold when compared with uncoated HAp and adsorbed rhBMP-2. It was concluded from this study that PEI and PEG tether significantly reduce the initial burst release effect of rhBMP-2. It was also concluded that the rhBMP-2 conjugation to PEI and PEG tether promoted an increase in cellular attachment to the HAp surface.
本研究旨在确定使用聚乙烯亚胺（PEI）和聚乙二醇（PEG）链将人重组骨形态发生蛋白-2（rhBMP-2）结合到羟基磷灰石（HAp）上来增强 rhBMP-2 负载、改变其释放特性并增强细胞与材料的相互作用的效果。通过使用衍生出表达游离硫醇的支化 PEI，将 rhBMP-2 涂覆到致密 HAp 表面上，达到约 43 ng/cm²。使用这种新颖的附着方法，观察到 PEI-SH 涂层不会改变 HAp 表面的形态，并且负载的 rhBMP-2 量与直接吸附方法相当。此外，还观察到 PEI 和 PEG 键合显著将 rhBMP-2 保留在 HAp 表面上，抑制了突释效应。使用人胎骨原代细胞，与未涂覆的 HAp 和吸附的 rhBMP-2 相比，PEI 和 PEG 键合的 BMP-2 也观察到细胞附着增加了 10 倍。本研究得出结论，PEI 和 PEG 键合显著降低了 rhBMP-2 的初始突释效应。还得出结论，rhBMP-2 与 PEI 和 PEG 键合促进了细胞对 HAp 表面的附着增加。
