Center for Environmental Nanoscience and Risk, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29223, USA; Department of Marine Vertebrates, Marine Science Center, University of Basrah, Iraq.
Center for Environmental Nanoscience and Risk, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29223, USA.
Colloids Surf B Biointerfaces. 2022 Jan;209(Pt 2):112173. doi: 10.1016/j.colsurfb.2021.112173. Epub 2021 Oct 26.
Nanoparticles (NPs) can be produced via physical, chemical, or biological approaches. Yet, the impact of the synthesis approaches on the environmental fate and effects of NPs is poorly understood. Here, we synthesized AgNPs through chemical and biological approaches (cit-AgNPs and bio-AgNPs), characterized their properties, and toxicities relative to commercially available Ag nanopowder (np-AgNPs) to the clam Mercenaria mercenaria. The chemical synthesis is based on the reduction of ionic silver using sodium borohydride as a reducing agent and trisodium citrate as a capping agent. The biological synthesis is based on the reduction of ionic silver using biomolecules extracted from an atoxigenic strain of a filamentous fungus Aspergillus parasiticus. The properties of AgNPs were determined using UV-vis, dynamic light scattering, laser Doppler electrophoresis, (single particle)-inductively coupled plasma-mass spectroscopy, transmission electron microscopy, and asymmetric flow-field flow fractionation. Both chemical and biological synthesis approaches generated spherical AgNPs. The chemical synthesis produced AgNPs with narrower size distributions than those generated through biological synthesis. The polydispersity of bio-AgNPs decreased with increases in cell free extract (CFE):Ag ratios. The magnitude of the zeta potential of the cit-AgNPs was higher than those of bio-AgNPs. All AgNPs formed aggregates in the test media i.e., natural seawater. Based on the same total Ag concentrations, all AgNPs were less toxic than AgNO. The toxicity of AgNPs toward the juvenile clam, Mercenaria mercenaria, decreased following the order np-AgNPs > cit-AgNPs > bio-AgNPs. Expressed as a function of dissolved Ag concentrations, the toxicity of Ag decreased following the order cit-AgNPs > bio-AgNPs > AgNO ~ np-AgNPs. Therefore, the toxicity of AgNP suspensions can be attributed to a combined effect of dissolved and particulate Ag forms. These results indicate that AgNP synthesis methods determine their environmental and biological behaviors and should be considered for a more comprehensive environmental risk assessment of AgNPs.
纳米粒子（NPs）可以通过物理、化学或生物方法来制备。然而，合成方法对 NPs 的环境归宿和效应的影响还了解甚少。在此，我们通过化学和生物方法（柠檬酸银 NPs 和生物银 NPs）合成了 AgNPs，对其性质和相对于市售的银纳米粉末（np-AgNPs）对贻贝 Mercenaria mercenaria 的毒性进行了表征。化学合成基于使用硼氢化钠作为还原剂和三磷酸钠作为封端剂将离子银还原。生物合成基于使用从无毒丝状真菌 Aspergillus parasiticus 的菌株中提取的生物分子将离子银还原。AgNPs 的性质使用紫外可见分光光度法、动态光散射、激光多普勒电泳、（单粒子）电感耦合等离子体质谱法、透射电子显微镜和不对称流场流分离法进行了测定。化学和生物合成方法都产生了球形 AgNPs。化学合成产生的 AgNPs 的粒径分布比生物合成产生的更窄。无细胞提取物（CFE）：Ag 比增加时，生物 AgNPs 的多分散性降低。柠檬酸银 NPs 的 ζ 电位绝对值高于生物银 NPs。在测试介质（即天然海水中）中，所有 AgNPs 均形成了聚集体。基于相同的总 Ag 浓度，所有 AgNPs 的毒性均低于 AgNO。AgNPs 对幼贻贝 Mercenaria mercenaria 的毒性顺序为 np-AgNPs > cit-AgNPs > bio-AgNPs。以溶解 Ag 浓度为函数，Ag 的毒性顺序为 cit-AgNPs > bio-AgNPs > AgNO~np-AgNPs。因此，AgNP 悬浮液的毒性可归因于溶解和颗粒 Ag 形式的综合效应。这些结果表明，AgNP 合成方法决定了它们的环境和生物学行为，应在更全面的 AgNPs 环境风险评估中考虑这些方法。
