Tong W, Glimcher M J, Katz J L, Kuhn L, Eppell S J
Nanoscale Orthopedic Biomaterials Laboratory, Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106-7207, USA.
Calcif Tissue Int. 2003 May;72(5):592-8. doi: 10.1007/s00223-002-1077-7. Epub 2003 May 6.
Atomic force microscopy (AFM) was used to obtain three-dimensional images of isolated mineralites extracted from young postnatal bovine bone. The mean mineralite size is 9 nm x 6 nm x 2.0 nm, significantly shorter and thicker than the mineralites of mature bovine bone measured by the same technique. Mineralites of the young postnatal bone can be accommodated within the hole zone regions of a quasi-hexagonally packed collagen fibril in the fashion described by Hodge [9] in which laterally adjacent hole zone regions form continuous "channels" across the diameter of a fibril for a distance of at least 10 nm. Deposition of mineralites of the size noted above in this void volume of the fibrils would result in little or no distortion of the collagen molecules or supramolecular structure of the collagen fibril. The new AFM data supporting this claim is consistent with findings obtained by electron microscopy and low-angle x-ray and neutron diffraction that mineralites formed within collagen fibrils during initial stages of calcification occur within the hole zone region. However, the deposition of additional mineralites in the intermolecular spaces between collagen molecules in the overlap region of the fibrils would significantly distort the fibrils since the space available between adjacent molecules is considerably less than even the smallest dimension of the mineralites.
原子力显微镜（AFM）被用于获取从新生牛骨中提取的孤立矿化物的三维图像。矿化物的平均尺寸为9纳米×6纳米×2.0纳米，比用相同技术测量的成熟牛骨的矿化物明显更短且更厚。新生牛骨的矿化物可以按照霍奇[9]所描述的方式容纳在准六边形排列的胶原纤维的孔区区域内，其中横向相邻的孔区区域在纤维直径上形成连续的“通道”，长度至少为10纳米。在纤维的这个空隙体积中沉积上述尺寸的矿化物，对胶原分子或胶原纤维的超分子结构几乎不会造成或不会造成扭曲。支持这一说法的新AFM数据与通过电子显微镜、低角度X射线和中子衍射获得的结果一致，即在钙化初始阶段在胶原纤维内形成的矿化物出现在孔区区域。然而，在纤维重叠区域的胶原分子之间的分子间空间中沉积额外的矿化物会显著扭曲纤维，因为相邻分子之间的可用空间甚至比矿化物的最小尺寸还要小得多。
