Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Acta Biomater. 2011 Apr;7(4):1760-71. doi: 10.1016/j.actbio.2010.12.030. Epub 2010 Dec 31.
Osteoinductive agents, such as BMP-2, are known to improve bone formation when combined with scaffolds. Microporosity (<20 μm) has also been shown to influence bone regeneration in calcium phosphate (CaP) scaffolds. However, many studies use only the term "osteoconductive" to describe the effects of BMP-2 and microporosity on bone formation, and do not assess the degree of healing that occurred. The objective of this study was to quantify the influence of BMP-2 and microporosity on bone regeneration and healing in biphasic calcium phosphate scaffolds using multiple measures including bone volume fraction, radial distribution, and specific surface area. These measures were quantitatively compared by analyzing microcomputed tomography data and used to formally define and assess healing. A custom image segmentation program was used to segment >100 samples, with 900 images each, that were implanted in porcine mandibular defects for 3, 6, 12 and 24 weeks. The assessment of healing presented in this work demonstrates the level of detail possible in evaluating scaffold-guided bone regeneration. The analysis shows that BMP-2 and microporosity accelerate healing up to 4-fold. BMP-2 and microporosity were shown to have different and complementary roles in bone formation that effect the time needed for a defect to heal.
骨诱导剂，如 BMP-2，与支架结合使用时被证明可以促进骨形成。微孔隙度（<20μm）也已被证明会影响磷酸钙（CaP）支架中的骨再生。然而，许多研究仅使用“骨传导性”一词来描述 BMP-2 和微孔隙度对骨形成的影响，而不评估发生的愈合程度。本研究的目的是使用多种测量方法，包括骨体积分数、径向分布和比表面积，定量评估 BMP-2 和微孔隙度对双相磷酸钙支架中骨再生和愈合的影响。通过分析微计算机断层扫描数据对这些测量值进行定量比较，并用于正式定义和评估愈合。使用自定义图像分割程序对超过 100 个样本进行分割，每个样本有 900 张图像，这些样本植入猪下颌骨缺损中 3、6、12 和 24 周。本工作中提出的愈合评估展示了评估支架引导骨再生的可能详细程度。分析表明，BMP-2 和微孔隙度将愈合速度提高了 4 倍。BMP-2 和微孔隙度在骨形成中具有不同且互补的作用，影响了缺陷愈合所需的时间。
