Polydopamine Surface Coating Synergizes the Antimicrobial Activity of Silver Nanoparticles
Polydopamine Surface Coating Synergizes the Antimicrobial Activity of Silver Nanoparticles
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DOI：
10.1021/acsami.0c10517
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发表时间：
2020-09-09
影响因子：
9.5
通讯作者：
Chen, Jingyi
中科院分区：
文献类型：
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作者：
Niyonshuti, Isabelle I.;Krishnamurthi, Venkata Rao;Chen, Jingyi
金属纳米颗粒，尤其是银纳米颗粒（AgNP），在抗菌应用中引起了越来越多的关注。大多数研究强调了银纳米颗粒的抗菌效力与金属银到离子银转化动力学之间的相关性，而其他抗菌机制被低估了。在这项工作中，我们专注于聚多巴胺（PDA）涂层对AgNPs的抗菌活性的表面效应。采用PDA快速沉积法制备了PDA-AgNPs，其涂层厚度在3 ~ 25 nm范围内可控。PDA-AgNPs的抗菌活性通过基于荧光的大肠杆菌生长曲线测定进行了分析。结果表明，PDA-AgNPs的抗菌活性明显高于PVP-AgNPs和PDA本身。发现PDA涂层与AgNP协同作用，以显著增强PDA-AgNP抗细菌的效力。X射线光电子能谱（XPS）和傅里叶变换红外光谱（FT-IR）分析表明，这种协同效应可能源于银与PDA涂层上邻苯二酚基团之间的相互作用/配位。协同效应导致活性氧的产生增加，从而导致细菌损伤。这些发现证明了表面效应对AgNPs的抗微生物性质的重要性。潜在的分子机制已经照亮了未来更有效的基于金属纳米颗粒的抗菌剂的发展。
Metal nanoparticles, especially silver nanoparticles (AgNPs), have drawn increasing attention for antimicrobial applications. Most studies have emphasized on the correlations between the antibacterial potency of AgNPs and the kinetics of metallic to ionic Ag conversion, while other antimicrobial mechanisms have been underestimated. In this work, we focused on the surface effects of polydopamine (PDA) coating on the antimicrobial activity of AgNPs. A method of fast deposition of PDA was used to synthesize the PDA-AgNPs with controllable coating thickness ranging from 3 to 25 nm. The antimicrobial activities of the PDA-AgNPs were analyzed by fluorescence-based growth curve assays on Escherichia coli. The results indicated that the PDA-AgNPs exhibited significantly higher antibacterial activities than poly(vinylpyrrolidone)-passivated AgNPs (PVP-AgNPs) and PDA themselves. It was found that the PDA coating synergized with the AgNPs to prominently enhance the potency of the PDA-AgNPs against bacteria. The analysis of X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy elucidated that the synergistic effects could be originated from the interaction/coordination between Ag and catechol group on the PDA coating. The synergistic effects led to increased generation of reactive oxygen species and the consequent bacterial damage. These findings demonstrated the importance of the surface effects on the antimicrobial properties of AgNPs. The underlying molecular mechanisms have shined light on the future development of more potent metal nanoparticle-based antimicrobial agents.