The effects of rhBMP-2 released from biodegradable polyurethane/microsphere composite scaffolds on new bone formation in rat femora
The effects of rhBMP-2 released from biodegradable polyurethane/microsphere composite scaffolds on new bone formation in rat femora
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DOI：
10.1016/j.biomaterials.2009.08.038
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发表时间：
2009-12-01
期刊：
影响因子：
14
通讯作者：
Guelcher, Scott A.
中科院分区：
文献类型：
--
作者：
Li, Bing;Yoshii, Toshitaka;Guelcher, Scott A.
由可生物降解聚氨酯（PUR）制备的支架已被研究作为皮肤，心血管和骨组织工程的支持基质和递送系统。虽然先前的研究表明PUR支架具有生物相容性和适度的骨传导性，但尚未研究这类生物材料中包封的骨诱导分子（如重组人骨形态发生蛋白（rhBMP-2））对新骨形成的影响。本研究的目的是研究不同的rhBMP-2释放策略对PUR支架植入大鼠股骨栓缺损中新骨形成的影响。在最简单的方法中，在发泡反应之前以干粉形式加入rhBMP-2，这导致35%的突释，随后持续释放21天。在发泡反应之前将rhBMP-2包封在1.3微米或114微米PLGA微球中减少了突释。在植入后4周，所有rhBMP-2治疗组相对于不含rhBMP-2的支架增强了新骨形成。含有rhBMP-2粉末的支架促进了最广泛的新骨形成，而含有封装在1.3微米微球中的rhBMP-2的支架表现出最低的突释，促进了最不广泛的新骨形成。因此，我们的观察结果表明，最初的爆发释放，然后持续释放是更好地促进新骨形成。(C)2009爱思唯尔有限公司保留所有权利。
Scaffolds prepared from biodegradable polyurethanes (PUR) have been investigated as a supportive matrix and delivery system for skin, cardiovascular, and bone tissue engineering. While previous studies have suggested that PUR scaffolds are biocompatible and moderately osteoconductive, the effects of encapsulated osteoinductive molecules, such as recombinant human bone morphogenetic protein (rhBMP-2), on new bone formation have not been investigated for this class of biomaterials. The objective of this study was to investigate the effects of different rhBMP-2 release strategies on new bone formation in PUR scaffolds implanted in rat femoral plug defects. In the simplest approach, rhBMP-2 was added as a dry powder prior to the foaming reaction, which resulted in a burst release of 35% followed by a sustained release for 21 days. Encapsulation of rhBMP-2 in either 1.3-micron or 114-micron PLGA microspheres prior to the foaming reaction reduced the burst release. At 4 weeks post-implantation, all rhBMP-2 treatment groups enhanced new bone formation relative to the scaffolds without rhBMP-2. Scaffolds incorporating rhBMP-2 powder promoted the most extensive new bone formation, while scaffolds incorporating rhBMP-2 encapsulated in 1.3-micron microspheres, which exhibited the lowest burst release, promoted the least extensive new bone formation. Thus our observations suggest that an initial burst release followed by sustained release is better for promoting new bone formation. (C) 2009 Elsevier Ltd. All rights reserved.