College of Marine Technology and Environment, Dalian Ocean University, Dalian 116023, China.
Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, College of environmental science and engineering, Dalian University of Technology, Dalian 116023, China.
Sci Total Environ. 2024 Nov 15;951:175690. doi: 10.1016/j.scitotenv.2024.175690. Epub 2024 Aug 22.
Microplastics and antibiotics are receiving increasing attention as two emerging pollutants in the aquatic ecosystem. The absorption of antibiotics by microplastics can potentially intensify their impact on marine organisms and human health. However, the detailed mechanisms underlying this interaction remain to be elucidated. Through molecular dynamics (MD) simulations and density functional theory (DFT) calculations, this study investigated the adsorption of cefradine (CED) onto three typical microplastics (MPs)-polyethylene (PE), polypropylene (PP), and polyamide (PA). The results of the molecular dynamics simulations showed that the interaction energy between CED and microplastics followed the order of PA-CED > PP-CED > PE-CED, indicating that PA microplastics had the highest adsorption capacity for CED antibiotics. The total energy contribution of the microplastics-cefradine (MPs-CED) systems suggested that the van der Waals and electrostatic interactions were the two primary mechanisms for the adsorption of CED by these three microplastics. In DFT calculations, the adsorption of CED on PA was found to be significantly influenced by both electrostatic and van der Waals effects, while the main driving force in the adsorption of PE and PP is van der Waals effect. In addition, IGMH analysis and AIM topological analysis confirmed that the adsorption of CED on PA relied heavily on the synergistic effect of hydrogen bonding and the van der Waals effect. The findings of this study validate the results obtained from molecular dynamics simulations, laying a foundation for a comprehensive exploration of the interaction mechanisms between microplastics and organic pollutants by integrating MD simulations and DFT calculations.
微塑料和抗生素作为水生生态系统中两种新兴的污染物，受到越来越多的关注。微塑料对抗生素的吸收可能会加剧它们对海洋生物和人类健康的影响。然而，这种相互作用的详细机制仍有待阐明。本研究通过分子动力学（MD）模拟和密度泛函理论（DFT）计算，研究了头孢菌素（CED）在三种典型的微塑料（MPs）-聚乙烯（PE）、聚丙烯（PP）和聚酰胺（PA）上的吸附。分子动力学模拟的结果表明，CED 与微塑料之间的相互作用能遵循 PA-CED>PP-CED>PE-CED 的顺序，表明 PA 微塑料对 CED 抗生素具有最高的吸附能力。微塑料-头孢菌素（MPs-CED）系统的总能量贡献表明，范德华和静电相互作用是 CED 被这三种微塑料吸附的两个主要机制。在 DFT 计算中，发现 CED 在 PA 上的吸附受到静电和范德华相互作用的显著影响，而在 PE 和 PP 吸附中主要驱动力是范德华相互作用。此外，IGMH 分析和 AIM 拓扑分析证实，CED 在 PA 上的吸附严重依赖于氢键和范德华相互作用的协同效应。本研究的结果验证了分子动力学模拟的结果，为通过整合 MD 模拟和 DFT 计算全面探索微塑料和有机污染物之间的相互作用机制奠定了基础。
