Localized tissue mineralization regulated by bone remodelling: A computational approach.
Localized tissue mineralization regulated by bone remodelling: A computational approach.
复制标题
DOI：
10.1371/journal.pone.0173228
复制
发表时间：
2017
期刊：
影响因子：
3.7
通讯作者：
Zioupos P
中科院分区：
文献类型：
--
作者：
Berli M;Borau C;Decco O;Adams G;Cook RB;García Aznar JM;Zioupos P
骨是一种活组织，其主要的机械功能是为身体提供刚度、强度和保护。硬度和强度都取决于有机基质的矿化，而有机基质不断地通过骨多细胞单位（BMU）的协调作用进行重塑。由于重塑和矿化的动力学，每个骨样本由不同时间产生的结构单元（皮质骨中的骨单位和松质骨中的骨包）组成，因此呈现不同水平的矿物质含量。在这项工作中，一个计算模型被用来了解在不同的负载条件和骨孔隙率的重塑和矿化过程之间的反馈。该模型认为，破骨细胞主要吸收那些更接近表面的骨部分，这些部分比旧的内部部分更年轻且矿化程度更低。在平衡载荷下，结果表明，与中等孔隙率的骨体积相比，具有最高和最低孔隙率水平的骨体积（分别为松质骨和皮质骨）倾向于形成更高水平的矿物质含量，从而呈现更高的材料密度。与最近的实验测量结果非常一致，当在组织水平绘制表观密度与在骨材料水平绘制材料密度时，出现了一个类似回力棒的图案。超载和停用状态进行了研究，导致在翻译的表观材料密度曲线。数值结果进行了讨论，指出潜在的临床应用。
Bone is a living tissue whose main mechanical function is to provide stiffness, strength and protection to the body. Both stiffness and strength depend on the mineralization of the organic matrix, which is constantly being remodelled by the coordinated action of the bone multicellular units (BMUs). Due to the dynamics of both remodelling and mineralization, each sample of bone is composed of structural units (osteons in cortical and packets in cancellous bone) created at different times, therefore presenting different levels of mineral content. In this work, a computational model is used to understand the feedback between the remodelling and the mineralization processes under different load conditions and bone porosities. This model considers that osteoclasts primarily resorb those parts of bone closer to the surface, which are younger and less mineralized than older inner ones. Under equilibrium loads, results show that bone volumes with both the highest and the lowest levels of porosity (cancellous and cortical respectively) tend to develop higher levels of mineral content compared to volumes with intermediate porosity, thus presenting higher material densities. In good agreement with recent experimental measurements, a boomerang-like pattern emerges when plotting apparent density at the tissue level versus material density at the bone material level. Overload and disuse states are studied too, resulting in a translation of the apparent–material density curve. Numerical results are discussed pointing to potential clinical applications.