金属和氧化物纳米颗粒对细菌毒性的研究进展

阐述了纳米颗粒的组分、尺寸、形状和表面电荷等性质与毒性的关系,介绍了纳米颗粒对革兰氏阴性菌和革兰氏阳性菌的毒性差异,指出了分散介质、暴露方式等毒性试验条件对纳米颗粒细菌毒性的影响,讨论了纳米颗粒对细菌毒性的可能机制,如氧化损伤、破坏细胞壁、作用于蛋白和核酸以及释放出金属离子等。针对目前纳米毒性研究尚处于起步阶段的现状,提出了建立纳米材料的毒性评价方法,加强从分子生物学水平开展对毒性机制的研究等建议。

Research advance review on the toxicity of nanoparticles to bacteria

The present paper is aimed to explore the influential factors of nanoparticles on the antibacterial activities,which can be found only by studying the particular features of nanoparticles and the differences of the internal factors of the bacteria,which are likely to exert remarkable effects on the antibacterial activities.To make a thorough study of the characteristic features of nanoparticles,we have first of all made a discussion in this paper of the composition,size,shape and surface charges of the nanoparticles.So far as we know,the toxicity of nanoparticles to bacteria may differ in the gram-positive and gramnegative bacteria,which is also the topic of our concern herein.Since gram-positive bacteria have only one membrane,they are more sensitive to nanoparticles than their counterpart of gram-negative ones,whose cell wall is more complicated with two membranes.However,opposite results were reported attributing the situation to the thicker cell wall of the gram-negative bacteria.It is said that it is the external factors,such as exposure modes and dispersed media,which influence the nanoparticles’ antibacterial activities to some extent and therefore should not be neglected.Based on the research results in recent years,we have analyzed and generalized the likely mechanisms of the toxicity of nanopaticles,among which,oxidation damage is the most likely accepted one,which leads to the lipid peroxidation and oxidative stress of the bacteria cells by producing active oxygen species.Besides,the nanoparticles may account for the death of bacteria by attacking the bacteria surface by destroying the cell membrane via physical and chemical interactions.It is also believed that nanoparticles could penetrate into the bacteria cells and interact with the protein and nucleic acids to kill the bacteria.Among all the above-said mechanisms,the toxicity caused by the released ions from nanoparticles remains most controversial and necessary to be better proved.And,finally,it is necessary to bring forward suggestions towards deeper research of the nanotoxicology in hoping to reveal new perspective in research directions.However,this paper is just intended to help better understand the negative effects of nanoparticles to organisms and promote the development of nanotechnology further in a healthy way.