Hashimoto Mana, Nagaoka Noriyuki, Tabata Kaori, Tanaka Tomoyo, Osumi Ryuta, Odagaki Naoya, Hara Toru, Kamioka Hiroshi
Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
Integr Biol (Camb). 2017 Nov 13;9(11):868-875. doi: 10.1039/c7ib00073a.
The collagen network acts as a scaffold for calcification and its three-dimensional structure influences bone strength. It is therefore important to observe the collagen network in detail and three-dimensionally. In this study, we observed the collagen network of chick embryonic calvariae in membranous bone three-dimensionally using orthogonally arranged FIB-SEM. A 25 × 25 μm area of chick embryonic calvaria was observed at a high resolution (25 nm per pixel). The inside of the bone (i.e. the primary calcified tissue), the bone cells (i.e. the osteoblasts and the osteocytes), the organelles, and the collagen fibrils were observed in detail. These structures were observed three-dimensionally using the Amira software program. In addition, the collagen fibrils of the bone were automatically extracted using the XTracing extension software program, and three-dimensional morphometry was performed. Almost all of the collagen fibrils ran along the longitudinal axis of the trabecular bone. We found that the regularity of the collagen fibril orientation was less remarkable in the osteoblast layer, which contained numerous osteoblasts. The collagen fibril orientation started to show regularity toward the central bone layer, which contained few bone cells.
胶原网络作为钙化的支架，其三维结构影响骨强度。因此，详细且三维地观察胶原网络很重要。在本研究中，我们使用正交排列的聚焦离子束扫描电子显微镜（FIB-SEM）三维观察了鸡胚颅骨膜性骨中的胶原网络。以高分辨率（每像素25纳米）观察了25×25微米的鸡胚颅骨区域。详细观察了骨内部（即初级钙化组织）、骨细胞（即成骨细胞和骨细胞）、细胞器和胶原纤维。使用Amira软件程序对这些结构进行了三维观察。此外，使用XTracing扩展软件程序自动提取骨的胶原纤维，并进行三维形态测量。几乎所有的胶原纤维都沿小梁骨的纵轴排列。我们发现，在含有大量成骨细胞的成骨细胞层中，胶原纤维取向的规律性不太明显。胶原纤维取向朝着含有少量骨细胞的中央骨层开始表现出规律性。
