Studies on Toxicity of Suspensions of CdTe Quantum Dots to Biomphalaria glabrata Mollusks

Abstract

Quantum dots have generated great interest because of their optical properties, both to life sciences and electronics applications. However, possible risks to the environment associated with these nanoparticles are still under investigation. The present study aimed to evaluate the toxicity of suspensions of cadmium telluride (CdTe) quantum dots to Biomphalaria glabrata mollusks, a very sensitive aquatic environmental bioindicator for physical and chemical agents. Toxicity was examined by using embryos and adult mollusks as well as hemocytes. The distribution of cadmium in the organs of adults was also assessed. Effects of the stabilizing agent of the quantum dots were also evaluated. Animals were exposed to suspensions of quantum dots for 24 h, at concentrations varying from 1.2 to 20 nM for embryos and from 50 to 400 nM for adult mollusks. Results showed that suspensions of quantum dots induced malformations and mortality in embryos and mortality in adults, depending on the concentration applied. In the cytotoxicity study, hemocyte apoptosis was observed in adults exposed to the highest concentration of quantum dots applied as well as to the stabilizing agent. Cell binucleation and micronucleus frequencies were not significative. Bioaccumulation evaluation revealed that quantum dots targeted the digestive gland (hepatopancreas). Taken together, outcomes suggested that specific nano‐effects related directly not only to composition but also to the aggregation of quantum dots may be mediating the observed toxicity. Thus B. glabrata was determined to be a very sensitive species for interpreting possible nano‐effects in aquatic environments. Environ Toxicol Chem 2019;38:2128–2136. © 2019 SETAC.

New Insights into the Gametogenesis of Biomphalaria glabrata (Mollusca, Gastropoda, Pulmonata): Implications for Histopathological Assessment

“…have been one of the widely used invertebrate model system in laboratories [8][9][10][11][12][13][14][15][16], mainly due to their short life cycle, ease of maintenance and reproduction [9,10]. A lot of research has used the snail as a biomonitor in ecotoxicological risk assessments due to its high sensibility to several aquatic pollutants [8,[11][12][13][14][15]. Also, invertebrates make up most of the fauna in aquatic environments [17] and may be used to assess the mode of action (MoA) and ecotoxicity of endocrine-disrupting chemicals (EDCs) [10,[18][19][20].…”

Exposure of Copper Nano-Particles (CuNPs) Impairs Developmental Stages and Hatchability in the Fresh Water Snail Indoplanorbis exustus (Planorbidae: Pulmonate)

“…In our study, the embryo hatched on 7 th day of exposure, there was significant decrease in percent hatchability, at 1.45and 1.93mg/L concentration, it might be very difficult for them to break the egg membrane; hence young ones could not hatch easily in time. After the exposure of CdTe NPs for 24 hon B. glabrata, decreased hatching, morphological alterations and reduced growth rate was observed [28]. The percent hatchability, growth of the foot, tentacles and shell as well as heart development appeared normal at lower concentrations like 0.96and 1.16mg/L concentration of CuNPs.…”

Toxicological evaluation of engineered layered double hydroxide nanomaterials to Biomphalaria alexandrina snails: a study on the mechanism of action

“…pfeifferi embryos following exposure to curcumin-nisin polylactic acid NPs for 96 h. In addition, Hydrophilic nanosilica induced embryotoxic effects in B. alexandrina snail at concentration 590 ppm for 6 h and 980 ppm for 48 h ( (Attia et al 2017). Similarly, the growth and hatching rate reduction was seen in B. glabrata embryos exposed to CdTe NPs for 24 h (Vasconcelos -Lima et al, 2019). In contrast, dimer captosuccinic acid (DMSA)-functionalized Fe 2 O 3 NPs did not induce embryo mortality, morphological alterations and hatching inhibition due to their physical properties and limited internalization in the eggclutches (Oliveira-lho et al, 2016).…”

“…Chronic exposure of the T. pisana to Ag NPs caused alterations in hemocytes, such as micronuclei, binucleated cell and kidney-like nuclei (Radwan et al 2019). Also, B. glabrata exposed to CdTe quantum dot showed altered hemocytes binucleates, micronuclei, and apoptosis (de Vasconcelos Lima et al 2019). Cell-cell aggregation was considered as an immunological response for host defense.…”

“…The embryotoxicity observed after exposure has been attributed to ROS production, oxidative stress and damage. Also, penetration of LDH NPs to gelatinous capsule and cross the egg membrane reduce essential growth metabolism aspects, changes in its permeability, consuming energy for the development and nally interrupting the mechanics of hatching (de Chavez and de Lara, 2003;de Vasconcelos Lima et al, 2019).…”