Expression of bioactivity through nano-sized defects and its regulation

哺乳动物骨骼和牙齿中的生物磷灰石含有多种矿物质，在晶体结构上具有许多纳米级的缺陷。在本研究中，我们制备了含骨矿物的羟基磷灰石陶瓷（骨HAp陶瓷）作为模型材料，以阐明生物磷灰石纳米缺陷结构与生物活性之间的关系。高分辨率透射电镜（HR-TEM）结果显示，骨HAp陶瓷比纯HAp陶瓷含有更多的缺陷和应变。此外，将取自大鼠骨髓细胞的成骨细胞植入骨HAp陶瓷上，并将纯HAp陶瓷作为对照。与纯HAp陶瓷相比，骨HAp陶瓷促进成骨细胞的分化。目前制备的羟基磷灰石骨陶瓷有望成为下一代人工骨移植物。

Biological apatite presented in bone and teeth of mammals contains various minerals, and has lots of defects with nano-scale sizes in the crystal structure. In the present study, we fabricated hydroxyapatite ceramics including bone minerals (bone HAp ceramics) as model materials to clarify the relationship between nano-defect structure and bioactivity of biological apatite. The results of high-resolution transmission electron microscope (HR-TEM) revealed that bone HAp ceramics contained more defects and strains compared to pure HAp ceramics. In addition, osteoblasts derived from rat bone marrow cells were seeded on bone HAp ceramics, together with pure HAp ceramics as a control. The bone HAp ceramics promoted the differentiation into osteoblast compared to pure HAp ceramics. The present bone HAp ceramics may be expected as next-generation artificial bone graft.