STRUCTURAL-ANALYSIS OF TURKEY TENDON COLLAGEN UPON REMOVAL OF THE INORGANIC PHASE
STRUCTURAL-ANALYSIS OF TURKEY TENDON COLLAGEN UPON REMOVAL OF THE INORGANIC PHASE
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DOI：
10.1016/0141-8130(91)90058-3
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发表时间：
1991-04-01
影响因子：
8.2
通讯作者：
KOCH, MHJ
中科院分区：
文献类型：
--
作者：
BIGI, A;RIPAMONTI, A;KOCH, MHJ
用小角X射线衍射和热重分析研究了经逐步脱矿降低无机相含量的钙化小腿屈肌腱。 X射线衍射结果与先前在钙化火鸡腱上获得的数据非常一致，表明用于脱钙腱的方法与钙化过程具有良好的对应性。 在热重扫描中可以检测到多达五个热过程：（1）水释放;（2）胶原分解;（3和4）残留有机组分的燃烧;（5）从磷灰石相中除去碳酸盐。 与未钙化的相比，钙化的胶原纤维具有较高的热稳定性，胶原分解的温度在较低的无机相含量下降低。 脱钙后胶原热稳定性的降低被胶原原纤维的结构有序性的降低所证实，如小角X射线衍射数据所示。 低至约40重量%无机相的脱钙不会显著改变规则排列在胶原蛋白的差距区内的无机块。 进一步去除无机相降至约15%wt引起小角度双正交反射的强度分布的变化，这可以归因于无机嵌段的平均高度的降低。 当无机相含量低于15wt%差距区域在空气干燥时由于无机嵌段的平均长度减小而更自由地收缩。
Calcified leg flexor tendons in which the inorganic phase content had been lowered by progressive demineralization were studied by small angle X-ray diffraction and thermogravimetry. The X-ray diffraction results agree very well with the data previously obtained on calcified turkey tendon indicating that the method used to decalcify tendons provides good correspondence with the process of calcification. Up to five thermal processes can be detected in the thermogravimetric scans: (1) water release; (2) collagen decomposition; (3 and 4) combustion of the residual organic components; (5) carbonate removal from the apatitic phase. The temperature of collagen decomposition decreases at lower inorganic phase content in agreement with the higher thermal stability of calcified collagen fibrils compared with uncalcified ones. The decrease of collagen thermal stability upon decalcification is paralleled by a decrease of the structural order of the collagen fibrils as indicated by small angle X-ray diffraction data. Decalcification down to about 40% wt of inorganic phase does not significantly alter the inorganic blocks that are regularly arranged inside the gap zone of the collagen. Further removal of inorganic phase down to about 15% wt provokes a variation of the intensity distribution of the small angle meridional reflections that can be ascribed to a reduction of the mean height of the inorganic blocks. At inorganic phase contents below 15% wt the gap region is more free to contract upon air drying as a result of the reduction of the mean length of the inorganic blocks.