Perdikouri Christina, Tägil Magnus, Isaksson Hanna
Division of Solid Mechanics, Lund University, Lund, Sweden,
Calcif Tissue Int. 2015 Jan;96(1):11-7. doi: 10.1007/s00223-014-9930-z. Epub 2014 Dec 25.
About 5-10% of all bone fractures suffer from delayed healing, which may lead to non-union. Bone morphogenetic proteins (BMPs) can be used to induce differentiation of osteoblasts and enhance the formation of the bony callus, and bisphosphonates help to retain the newly formed callus. The aim of this study was to investigate if scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) can identify differences in the mineral composition of the newly formed bone compared to cortical bone from a non-fractured control. Moreover, we investigate whether the use of BMPs and bisphosphonates-alone or combined-may have an effect on bone mineralization and composition. Twelve male Sprague-Dawley rats at 9 weeks of age were randomly divided into four groups and treated with (A) saline, (B) BMP-7, (C) bisphosphonates (Zoledronate), and (D) BMP-7 + Zoledronate. The rats were sacrificed after 6 weeks. All samples were imaged using SEM and chemically analyzed with EDS to quantify the amount of C, N, Ca, P, O, Na, and Mg. The Ca/P ratio was the primary outcome. In the fractured samples, two areas of interest were chosen for chemical analysis with EDS: the callus and the cortical bone. In the non-fractured samples, only the cortex was analyzed. Our results showed that the element composition varied to a small extent between the callus and the cortical bone in the fractured bones. However, the Ca/P ratio did not differ significantly, suggesting that the mineralization at all sites is similar 6 weeks post-fracture in this rat model.
所有骨折中约5%-10%会出现愈合延迟，这可能导致骨不连。骨形态发生蛋白（BMPs）可用于诱导成骨细胞分化并增强骨痂形成，而双膦酸盐有助于保留新形成的骨痂。本研究的目的是调查扫描电子显微镜（SEM）和能量色散X射线光谱（EDS）能否识别新形成骨的矿物质组成与未骨折对照的皮质骨之间的差异。此外，我们研究单独使用或联合使用BMPs和双膦酸盐是否会对骨矿化和组成产生影响。将12只9周龄的雄性Sprague-Dawley大鼠随机分为四组，分别用（A）生理盐水、（B）BMP-7、（C）双膦酸盐（唑来膦酸）和（D）BMP-7+唑来膦酸进行治疗。6周后处死大鼠。所有样本均使用SEM成像并用EDS进行化学分析，以量化C、N、Ca、P、O、Na和Mg的含量。Ca/P比值是主要观察指标。在骨折样本中，选择两个感兴趣的区域用EDS进行化学分析：骨痂和皮质骨。在未骨折样本中，仅分析皮质骨。我们的结果表明，骨折骨的骨痂和皮质骨之间的元素组成在小范围内有所不同。然而，Ca/P比值没有显著差异，这表明在该大鼠模型中，骨折后6周所有部位的矿化情况相似。
