National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, PR China.
National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, PR China.
Colloids Surf B Biointerfaces. 2021 Aug;204:111822. doi: 10.1016/j.colsurfb.2021.111822. Epub 2021 May 12.
Biomineralization approaches have been increasingly adopted to synthesizing advanced materials with superior properties. Nevertheless, the potential influence of inorganic trace elements on the mineralization process of collagen has been rarely reported, despite of the significant progress achieved on exploiting the critical roles of organic polymers in regulating the collagen mineralization. To this aim, the potential roles of Si, Zn and Sr in regulating the mineralization of gelatin-hydroxyapatite (HA) composite fibers have been examined in this study. The results indicated that the incorporation of trace elements not only promoted the biomineralization of gelatin, but also led to drastic change in the mineralization behavior. In particular, the gelatin-SiHA sample showed uniform mineralization predominantly inside the fibers, with nucleation and growth directions along the c-axis of the gelatin fibers. On the contrary, the gelatin-HA sample showed nucleation outside the fibers and spherical mineral crystals on top of fibers, typical structure for heterogeneous nucleation. As the mineralization process proceeded, the gelatin-ZnHA and gelatin-SrHA samples evolved into having similar structure as the gelatin-SiHA sample, despite of showing totally different mineralization behaviors at early time. Overall, the incorporation of trace elements seemed to lower the nucleation barriers, led to a more homogeneous mineralization mode within the fiber region and formation of mineralized structures closer to those in natural bone. Moreover, mineralized samples with trace elements demonstrated improved adhesion and cytoskeleton organization of osteoblastic cells. Such finding would provide important insight for understanding the mineralization process and the optimal design of advanced biological materials.
生物矿化方法已被越来越多地应用于合成具有优异性能的先进材料。然而，尽管在利用有机聚合物在调节胶原蛋白矿化方面的关键作用方面取得了显著进展，但无机微量元素对胶原蛋白矿化过程的潜在影响却很少有报道。为此，本研究考察了 Si、Zn 和 Sr 在调控明胶-羟基磷灰石（HA）复合纤维矿化过程中的潜在作用。结果表明，微量元素的掺入不仅促进了明胶的生物矿化，而且还导致矿化行为发生了剧烈变化。特别是明胶-SiHA 样品表现出主要在纤维内部均匀矿化，其成核和生长方向沿明胶纤维的 c 轴。相比之下，明胶-HA 样品表现出在纤维外成核和纤维顶部形成球形矿化晶体，这是异质成核的典型结构。随着矿化过程的进行，尽管在早期表现出完全不同的矿化行为，明胶-ZnHA 和明胶-SrHA 样品仍演变成具有与明胶-SiHA 样品相似的结构。总的来说，微量元素的掺入似乎降低了成核势垒，导致纤维区域内更均匀的矿化模式，并形成更接近天然骨的矿化结构。此外，含有微量元素的矿化样品表现出增强的成骨细胞黏附和细胞骨架组织。这些发现为理解矿化过程和先进生物材料的优化设计提供了重要的见解。
