Molecular Dynamics Characterization of Sr-Doped Biomimetic Hydroxyapatite Nanoparticles
Molecular Dynamics Characterization of Sr-Doped Biomimetic Hydroxyapatite Nanoparticles
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DOI：
10.1021/acs.jpcc.0c06391
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发表时间：
2020-09-10
影响因子：
3.7
通讯作者：
Xu, Dingguo
中科院分区：
文献类型：
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作者：
Liu, Qingyu;Xue, Zhiyu;Xu, Dingguo
羟基磷灰石（Hydroxyapatite， HAP）是人类骨骼和牙齿的主要无机成分，作为种植材料受到广泛关注。在HAP晶格结构中掺杂外来离子是赋予和增强其生物学特性的一种有价值的方法。本研究在第一性原理计算的基础上，首先用遗传算法拟合了HAP中取代的锶离子的力场参数。然后通过分子动力学模拟表征了相应的掺锶HAP的体积和表面性质。计算了0 ~ 100 at的晶格结构、熔化温度、红外光谱和弹性参数。% sr掺杂HAP与实验结果吻合较好。构建了几个完全sr取代HAP的模型，以了解不同pH值的影响。我们的模拟表明，随着pH值的降低，sr取代HAP可能表现出更高的溶解度。同时，Sr离子倾向于吸附在HAP表面，且吸附量随着ph的增加而增加。最后，Sr离子的取代可能会减弱Glu侧链类似物在HAP表面的吸附，而增强Lys侧链类似物在HAP表面的吸附。本研究建立的Sr的力场参数可以应用于后续研究Sr掺杂HAP与其他生物分子之间的相互作用。
Hydroxyapatite (HAP), which is the main inorganic component of human bones and teeth, has received much attention for its use as an implant material. Doping foreign ions into the HAP lattice structure is a valuable approach to endow and augment its biological characteristics. In this study, based on first-principles calculations, the force-field parameters of strontium ions substituted in HAP were first fitted by a genetic algorithm. The corresponding Sr-doped HAP bulk and surface properties were then characterized by molecular dynamics simulations. The calculated lattice structure, melting temperature, infrared spectra, and elastic parameters of 0-100 at.% Sr-doped HAP are in good agreement with the experimental observations. Several models with fully Sr-substituted HAP were constructed to understand the effects of different pH values. Our simulations indicate that Sr-substituted HAP might exhibit higher solubility along with decreasing pH values. Meanwhile, Sr ions tend to adsorb onto the HAP surface, and the amount of adsorption increases with increasing pH. Finally, the substitution of Sr ions might weaken the adsorption of Glu side-chain analogues but strengthen the adsorption of Lys side-chain analogues on the HAP surface. The force-field parameters developed for Sr in this work could be applied to subsequent studies for interactions between Sr-doped HAP and other biomolecules.