Department of Materials Science and Engineering, National Chung Hsing University, Taichung 40227, Taiwan.
J Mech Behav Biomed Mater. 2011 Oct;4(7):1412-20. doi: 10.1016/j.jmbbm.2011.05.011. Epub 2011 May 13.
In this study, the bone structures, nanomechanical properties and fracture behaviors in different groups of female C57BL/6 mice (control, sham operated, ovariectomized, casein supplemented, and fermented milk supplemented) were examined by micro-computed tomography, scanning and transmission electron microscopy, and nanoindentation. The control and sham operated mice showed dense bone structures with high cortical bone mineral densities of 544 mg/cm(3) (average) and high hardness of 0.9-1.1 GPa; resistance to bone fracture was conferred by microcracking, crack deflections and ligament bridging attributed to aligned collagen fibers and densely packed hydroxyapatite crystals. Bone mineral density, hardness and fracture resistance in ovariectomized mice markedly dropped due to loose bone structure with randomly distributed collagens and hydroxyapatites. The acidic casein supplemented mice with blood acidosis exhibited poor mineral absorption and loose bone structure, whereas the neutralized casein or fermented milk supplemented mice were resistant to osteoporosis and had high bone mechanical properties.
本研究通过微计算机断层扫描、扫描和透射电子显微镜以及纳米压痕技术，研究了不同组别的雌性 C57BL/6 小鼠（对照组、假手术组、去卵巢组、酪蛋白补充组和发酵乳补充组）的骨结构、纳米力学性能和骨折行为。对照组和假手术组的小鼠具有致密的骨结构，皮质骨矿物质密度高，平均为 544mg/cm(3)，硬度高，为 0.9-1.1GPa；由于胶原纤维排列整齐，羟基磷灰石晶体紧密堆积，微裂纹、裂纹偏转和韧带桥接赋予了它们抗骨折的能力。由于去卵巢小鼠的骨结构疏松，胶原和羟基磷灰石分布随机，导致骨矿物质密度、硬度和抗骨折能力明显下降。酸性酪蛋白补充小鼠因血液酸中毒而表现出较差的矿物质吸收和疏松的骨结构，而中和后的酪蛋白或发酵乳补充小鼠则能抵抗骨质疏松症，具有较高的骨力学性能。
