Kaiser Jean-Pierre, Roesslein Matthias, Diener Liliane, Wichser Adrian, Nowack Bernd, Wick Peter
Particles-Biology Interactions Laboratory, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014, St. Gallen, Switzerland.
Technology and Society Laboratory, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014, St. Gallen, Switzerland.
J Nanobiotechnology. 2017 Jan 6;15(1):5. doi: 10.1186/s12951-016-0244-3.
Nanosilver shows great promise for use in industrial, consumer or medical products because of its antimicrobial properties. However, the underlying mechanisms of the effects of silver nanoparticles on human cells are still controversial. Therefore, in the present study the influence of the chloride concentration and different serum content of culture media on the cytotoxic effects of nanosilver was systematically evaluated.
Our results show that nanosilver toxicity was strongly affected by the composition of the culture media. The chloride concentration, as well as the carbon content affected the silver agglomeration and the complex formation. But also the dissolution of nanosilver and the availability of free silver ions (Ag) were severely affected by the compositions of the culture media. Cells, only exposed to silver particles in suspension and dissolved silver complexes, did not show any effects under all conditions. Nanosilver agglomerates and silver complexes were not very soluble. Thus, cells growing on the bottom of the culture dishes were exposed to sedimented nanosilver agglomerates and precipitated silver complexes. Locally, the concentration of silver on the cell surface was very high, much higher compared the silver concentration in the bulk solution. The cytotoxic effects of nanosilver are therefore a combination of precipitated silver complexes and organic silver compounds rather than free silver ions.
Silver coatings are used in health care products due to their bacteriostatic or antibacterial properties. The assessment of the toxicity of a certain compound is mostly done using in vitro assays. Therefore, cytotoxicity studies of nanosilver using human cell cultures have to be undertaken under well controlled and understood cultivations conditions in order to improve the compatibility of different studies. Especially when eukaryotic versus prokaryotic systems are compared for the evaluation of the use of nanosilver as antibacterial coatings for implants in order to prevent bacterial colonization.
纳米银因其抗菌特性在工业、消费品或医疗产品中具有巨大的应用前景。然而，银纳米颗粒对人体细胞作用的潜在机制仍存在争议。因此，在本研究中，系统评估了培养基中氯化物浓度和不同血清含量对纳米银细胞毒性作用的影响。
我们的结果表明，纳米银的毒性受到培养基成分的强烈影响。氯化物浓度以及碳含量影响银的团聚和络合物的形成。而且，培养基的成分也严重影响纳米银的溶解以及游离银离子（Ag）的可用性。仅暴露于悬浮的银颗粒和溶解的银络合物中的细胞在所有条件下均未表现出任何影响。纳米银团聚物和银络合物的溶解性不是很好。因此，生长在培养皿底部的细胞暴露于沉淀的纳米银团聚物和沉淀的银络合物中。在局部，细胞表面的银浓度非常高，与本体溶液中的银浓度相比要高得多。因此，纳米银的细胞毒性作用是沉淀的银络合物和有机银化合物的组合，而不是游离银离子。
银涂层因其抑菌或抗菌特性而用于医疗保健产品。某种化合物的毒性评估大多使用体外试验进行。因此，使用人类细胞培养进行纳米银的细胞毒性研究必须在严格控制和理解的培养条件下进行，以提高不同研究的可比性。特别是在比较真核与原核系统以评估纳米银作为植入物抗菌涂层以防止细菌定植的用途时。
