Nanomaterials toxicity and teratogenicity in aquatic environment using Rhinella arenarum model

Abstract

Nanotechnology is growing at an exponential rate and will undoubtedly have both beneficial and toxicological impact and consequences on health and environment. Amphibians are being increasingly used for toxicity screening purposes due to their high sensitivity to physicochemical stress and useful indicators of freshwater contamination. Amphibians, with lifestage comprising embryos, tadpoles, and adults, have an extremely permeable skin, which makes them excellent indicators of environmental health. Rhinella arenarum is widely distributed in our region (Río Cuarto, Cordoba Province, Argentina). AMPHITOX is a set of customized toxicity test for acute, short term chronic, chronic andearly life stages of amphibian embryos of R. arenarum, which allow selecting the most appropriate exposure period and end points according to the toxicity of the sample and the purpose of the study.The main purpose of this study is to evaluate the susceptibility of embryos at 2-4 blastomeric stage (s2-s4) and larvaein premetamorphosis (stage 25) (AMPHITOX bio assay) to different concentrations of polyaniline (PANI) nanomaterials (nanofibersand nanoparticles). The susceptibility of R. arenarum larvae to PANI duringthe 25th stage of development was evaluated by exposing the larvae to different concentrations of each nanomaterial. On the otherhand, the teratogenic assay of different nanomaterials to embryos was carried out by observing the embryotoxic effects at continuousexposure from early blastula (S.2?S.4) during a 96 h period. These results demonstrated a stage-dependent susceptibility for PANI-nanomaterials. Early stage embryos are more sensitive than more mature embryos. The mayor toxicity perhaps it could be attributed to the minor size of the nanomaterials and its bioaccumulation. This in vivo model might serve to determine not only the PANI toxicity but also other nanomaterials, consequently this popular alternative organism can be extensively used as models in nanotoxicology.