Komazec Bruno, Cvjetko Petra, Balen Biljana, Letofsky-Papst Ilse, Lyons Daniel Mark, Peharec Štefanić Petra
Department of Biology, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000 Zagreb, Croatia.
Institute of Electron Microscopy and Nanoanalysis (FELMI), Graz Centre for Electron Microscopy (ZFE), Austrian Cooperative Research (ACR), Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria.
Nanomaterials (Basel). 2023 Jun 28;13(13):1967. doi: 10.3390/nano13131967.
Silver nanoparticles (AgNPs) are of great interest due to their antimicrobial properties, but their reactivity and toxicity pose a significant risk to aquatic ecosystems. In biological systems, AgNPs tend to aggregate and dissolve, so they are often stabilized by agents that affect their physicochemical properties. In this study, microalga was used as a model organism to evaluate the effects of AgNPs in aquatic habitats. Algae were exposed to AgNPs stabilized with citrate and cetyltrimethylammonium bromide (CTAB) agents and to AgNO at concentrations that allowed 75% cell survival after 72 h. To investigate algal response, silver accumulation, ROS content, damage to biomolecules (lipids, proteins, and DNA), activity of antioxidant enzymes (APX, PPX, CAT, SOD), content of non-enzymatic antioxidants (proline and GSH), and changes in ultrastructure were analyzed. The results showed that all treatments induced oxidative stress and adversely affected algal cells. AgNO resulted in the fastest death of algae compared to both AgNPs, but the extent of oxidative damage and antioxidant enzymatic defense was similar to AgNP-citrate. Furthermore, AgNP-CTAB showed the least toxic effect and caused the least oxidative damage. These results highlight the importance of surface-stabilizing agents in determining the phytotoxicity of AgNPs and the underlying mechanisms affecting aquatic organisms.
银纳米颗粒（AgNPs）因其抗菌特性而备受关注，但其反应性和毒性对水生生态系统构成重大风险。在生物系统中，AgNPs往往会聚集和溶解，因此它们通常由影响其物理化学性质的试剂来稳定。在本研究中，微藻被用作模式生物来评估AgNPs在水生生境中的影响。将藻类暴露于用柠檬酸盐和十六烷基三甲基溴化铵（CTAB）试剂稳定的AgNPs以及AgNO₃中，浓度设定为使72小时后细胞存活率达到75%。为了研究藻类的反应，分析了银的积累、活性氧含量、对生物分子（脂质、蛋白质和DNA）的损伤、抗氧化酶（APX、PPX、CAT、SOD）的活性、非酶抗氧化剂（脯氨酸和谷胱甘肽）的含量以及超微结构的变化。结果表明，所有处理均诱导了氧化应激并对藻类细胞产生了不利影响。与两种AgNPs相比，AgNO₃导致藻类死亡最快，但氧化损伤程度和抗氧化酶防御与柠檬酸银纳米颗粒相似。此外，CTAB修饰的银纳米颗粒毒性最小，造成的氧化损伤也最少。这些结果凸显了表面稳定剂在确定AgNPs植物毒性以及影响水生生物的潜在机制方面的重要性。
