Development ofin vitrosystems for nanotoxicology: methodological considerations

Abstract

Due to the rapid development of a diverse array of nanoparticles, used in a wide variety of products, there are now many international activities to assess the potential toxicity of these materials. These particles are developed due to properties such as catalytic reactivity, high surface area, light emission properties, and others. Such properties have the potential to interfere in many well-established toxicity testing protocols. This article outlines some of the most frequently used assays to assess the cytotoxity and biological reactivity of nanoparticles in vitro. The article identifies key issues that need to be addressed in relation to inclusion of relevant controls, assessing particles for their ability to interfere in the assays, and using systematic approaches to prevent misinterpretation of data. The protocols discussed range from simple cytotoxicity assays, to measurement of reactive oxygen species and oxidative stress, activation of proinflammatory signaling, and finally genotoxicity. The aim of this review is to share knowledge relating to nanoparticle toxicity testing in order to provide advice and support for guidelines, regulatory bodies, and for scientists in general.

Silver nanoparticles induce cytotoxicity, but not cell transformation or genotoxicity on Balb3T3 mouse fibroblasts

“…In addition, if we express the NPs concentration considering the corresponding number of NPs per milliliter (number of NPs/mL) or surface area (cm 2 /mL), it would lead to different conclusions as for a fixed concentration the number of NPs/mL increases as the particle size decreases, causing the doseeffect curves to shift and showing less toxicity induced by smaller Ag NPs (72 h of exposure), or similar toxicity for all the NPs tested for the surface area (cm 2 /mL) expression, in the same exposure conditions. This observation highlights the need to agree on a standard way to express the amount of NPs used for the treatments and to allow comparison of data produced by different research groups [44].…”

Value of phagocyte function screening for immunotoxicity of nanoparticles in vivo

“…[91][92][93][94][95] Depending on the assays used, the masking of toxic effects and the identification of nonexistent toxicity by NPs can occur simultaneously. Increased absorbance by colored NPs will result in a higher signal of LDH (indicating more dead cells) and in the MTT assay (indicating more viable cells).…”

DNA gel particles: An overview

“…Interactions of nanomaterials assays include interference by adsorption of dyes [112], absorbance [113], fluorescence [114], binding of proteins [115], dye degradation [116] and dye formation [112], among others.…”