Mechanical Engineering Department, Indian Institute of Technology Delhi, New Delhi, 110016, India.
Mechanical Engineering Department, Indian Institute of Technology Delhi, New Delhi, 110016, India.
J Mech Behav Biomed Mater. 2023 Nov;147:106125. doi: 10.1016/j.jmbbm.2023.106125. Epub 2023 Sep 28.
Nanocomposite material composed of Bombyx mori Silk Fibroin and hydroxyapatite (B. mori SF-HA) is a potential biomaterial for bone tissue engineering. Here, Bombyx mori Silk Fibroin (B. mori SF) is a flexible and tough organic, polymer phase, and hydroxyapatite (HA) is hard and stiff mineral phase. Knowledge about mechanical deformation behavior together with governing mechanisms, and the role of the two phases (SF and HA phase) and interfacial interactions between them, in B. mori SF-HA biomaterial, at fundamental level is an important factor to consider while developing the tissue grafts. Such nanometer scale behavior is often preferably investigated using molecular dynamics method. Present study aims at understanding the mechanical deformation behavior and associated physical mechanisms in B. mori SF-HA bio-nanocomposite, at nanoscale. For this purpose, computational atomistic models of B. mori SF-HA bio-nanocomposite are developed with varying HA content. Mechanical behavior analysis of these composite models under tensile loading were performed using Molecular Dynamics (MD) simulations. Elastic modulus and tensile strength values in the range of 7-20 GPa and 200-700 MPa, respectively, are obtained for B. mori SF-HA composite, in case of different HA contents, wherein, increased mechanical properties are observed with increase in HA content. Analyses of the deformation trajectories show that the deformation flow behavior in B. mori SF-HA bio-nanocomposites is mainly defined by the soft SF phase. However, energetics analyses show that, the HA phase and SF-HA interfacial interactions also play a considerable role in mechanical performance of B. mori SF-HA bio-nanocomposite. Additionally, interfacial shear strength values in B. mori SF-HA bio-nanocomposite, for different HA contents, have also been obtained. The observations made and insights gained in present work has contribution and impact in gaining an insight into the mechanistic interactions occurring at nanoscale between SF and HA phases in B. mori SF-HA bio-composite.
由桑蚕丝素蛋白和羟基磷灰石（B. mori SF-HA）组成的纳米复合材料是骨组织工程的一种有前途的生物材料。在这里，桑蚕丝素蛋白（B. mori SF）是一种柔韧而坚韧的有机聚合物相，而羟基磷灰石（HA）则是坚硬而僵硬的矿物质相。了解机械变形行为以及控制机制，以及两相（SF 和 HA 相）及其界面相互作用在 B. mori SF-HA 生物材料中的作用，是在开发组织移植物时需要考虑的一个重要因素。这种纳米级行为通常最好使用分子动力学方法进行研究。本研究旨在了解 B. mori SF-HA 生物纳米复合材料的机械变形行为和相关物理机制，在纳米尺度上。为此，使用不同 HA 含量的方法，为 B. mori SF-HA 生物纳米复合材料开发了计算原子模型。通过分子动力学（MD）模拟对这些复合模型在拉伸载荷下的力学行为进行了分析。在不同的 HA 含量下，B. mori SF-HA 复合材料的弹性模量和拉伸强度值分别在 7-20 GPa 和 200-700 MPa 范围内，其中随着 HA 含量的增加，力学性能得到提高。变形轨迹的分析表明，B. mori SF-HA 生物纳米复合材料的变形流动行为主要由柔软的 SF 相决定。然而，能量分析表明，HA 相和 SF-HA 界面相互作用在 B. mori SF-HA 生物纳米复合材料的力学性能中也起着相当大的作用。此外，还获得了不同 HA 含量下 B. mori SF-HA 生物纳米复合材料的界面剪切强度值。本工作中的观察和见解对深入了解 B. mori SF-HA 生物复合材料中 SF 和 HA 相之间在纳米尺度上发生的机械相互作用有贡献和影响。
