Hong S I, Hong S K, Wallace J M, Kohn D H
Department of Biologic and Materials Sciences, University of Michigan, Ann Arbor, MI, 48109-1078, USA.
J Mater Sci Mater Med. 2009 Apr;20(4):959-65. doi: 10.1007/s10856-008-3651-7. Epub 2008 Nov 26.
The ultrastructure of murine femoral lamellar bone and the effect of electron irradiation (200 kV) on collagen and mineral features were investigated using in situ high resolution transmission electron microscopy (HRTEM). Bands of collagen fibrils were mostly aligned parallel to the long axis of the bones, with some bands of fibrils inclined in longitudinal sections. The similarity of the ultrastructure between the longitudinal and transverse sections supports the rotated plywood structure of the lamellar bone. The collagen fibrils appeared damaged and the mineral crystals were coarsened after electron irradiation. Continuous diffraction rings became spotty and the contrast between rings and the background became sharper, further suggesting coarsening of apatite crystals and increased crystallinity after irradiation. No new phases were observed after irradiation. Both the damage to collagen and coarsening of apatite crystals can deteriorate the strength and integrity of bone, and may provide insight into fracture in patients who have undergone radiation therapy.
利用原位高分辨率透射电子显微镜（HRTEM）研究了小鼠股骨板层骨的超微结构以及电子辐照（200 kV）对胶原和矿物质特征的影响。胶原纤维束大多与骨的长轴平行排列，在纵切面上有一些纤维束呈倾斜状。纵切面和横切面超微结构的相似性支持了板层骨的旋转胶合板结构。电子辐照后，胶原纤维出现损伤，矿物质晶体变粗。连续的衍射环变成斑点状，环与背景之间的对比度变得更清晰，进一步表明辐照后磷灰石晶体变粗且结晶度增加。辐照后未观察到新相。胶原的损伤和磷灰石晶体的粗化都会使骨的强度和完整性恶化，并可能为接受放射治疗的患者骨折提供见解。
