Influence of the degradation of the organic matrix on the microscopic fracture behavior of trabecular bone
Influence of the degradation of the organic matrix on the microscopic fracture behavior of trabecular bone
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DOI：
10.1016/j.bone.2004.05.027
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发表时间：
2004-11-01
期刊：
影响因子：
4.1
通讯作者：
Hansma, PK
中科院分区：
文献类型：
--
作者：
Fantner, GE;Birkedal, H;Hansma, PK
近年来，有机基质对于骨力学性能的重要作用日益显现。因此，了解骨的有机和无机成分之间的相互作用，并了解有机基质促成这种复杂生物材料的显着特性的机制，是非常有意义的。在本文中，我们提出了由于热诱导的有机基质降解而导致的骨特性变化的多方面观点。我们比较了健康牛小梁骨与具有热降解有机基质的小梁骨的微观断裂行为（扫描电子显微镜；SEM）、表面形貌（原子力显微镜；AFM）、骨成分状况[X射线衍射（XRD）、热重分析（TGA）和凝胶电泳]以及宏观力学特性。我们表明热处理改变了骨小梁的微骨折行为。未经处理的骨小梁的主要失效模式是原纤维引导的分层，矿化的胶原丝桥接微裂纹的间隙。相比之下，在 200 摄氏度下烘烤的骨头会像脆性材料一样无方向性地断裂，并且没有纤维跨越微裂纹。最后，在PBS溶液中煮沸2小时的骨因脱层而断裂，微裂纹中有许多小丝跨越，使得微裂纹的边缘变得难以区分。在我们使用的方法中，烘烤最有效地削弱骨骼的机械强度，产生最脆的材料。煮过的骨头比烤过的骨头更强，但比未经处理的骨头弱。煮过的骨头比未经处理的骨头更有弹性，而未经处理的骨头又比烤过的骨头更有弹性。这些研究清楚地强调了有机基质在影响骨断裂力学方面的重要性。 (C) 2004 Elsevier Inc. 保留所有权利。
In recent years, the important role of the organic matrix for the mechanical properties of bone has become increasingly apparent. It is therefore of great interest to understand the interactions between the organic and inorganic constituents of bone and learn the mechanisms by which the organic matrix contributes to the remarkable properties of this complex biomaterial. In this paper, we present a multifaceted view of the changes of bone's properties due to heat-induced degradation of the organic matrix. We compare the microscopic fracture behavior (scanning electron microscopy; SEM), the topography of the surfaces (atomic force microscopy; AFM), the condition of bone constituents [X-ray diffraction (XRD), thermogravimetric analysis (TGA), and gel electrophoresis], and the macromechanical properties of healthy bovine trabecular bone with trabecular bone that has a heat-degraded organic matrix. We show that heat treatment changes the microfracture behavior of trabecular bone. The primary failure mode of untreated trabecular bone is fibril-guided delamination, with mineralized collagen filaments bridging the gap of the microcrack. In contrast, bone that has been baked at 200degreesC fractures nondirectionally like a brittle material, with no fibers spanning the microcracks. Finally, bone that has been boiled for 2 h in PBS solution fractures by delarnination with many small filaments spanning the microcracks, so that the edges of the microcracks become difficult to distinguish. Of the methods we used, baking most effectively weakens the mechanical strength of bone, creating the most brittle material. Boiled bone is stronger than baked bone, but weaker than untreated bone. Boiled bone is more elastic than untreated bone, which is in turn more elastic than baked bone. These studies clearly emphasize the importance of the organic matrix in affecting the fracture mechanics of bone. (C) 2004 Elsevier Inc. All rights reserved.