Correction for 'Toxicokinetics of pristine and aged silver nanoparticles in
Physa acuta
' by Patrícia V. Silva
et al.
,
Environ. Sci.: Nano
, 2020,
7
, 3849-3868, DOI:
10.1039/D0EN00946F
.
Aquatic environments, particularly sediments, can be important final sinks for engineered nanoparticles (ENPs), with benthic biota being potentially exposed. There is an increasing need for hazard ...data to improve the environmental risk assessment of ENPs regarding aquatic systems. The aim of this study was to determine the toxicokinetics of several pristine (as manufactured) Ag-NPs, Ag
2
S-NPs (used to simulate environmental aging of silver nanoparticles) and AgNO
3
as the ionic counterpart, in the freshwater snail
Physa acuta
. Snails were exposed through 1) contaminated water (without sediment), 2) contaminated water and clean sediment, and 3) contaminated sediment. Bioavailability of Ag to the snails was greatly influenced by Ag characteristics, as different uptake and elimination kinetics were found for the different Ag forms within the same exposure route. Snails exposed
via
water revealed, in general, similar uptake kinetics, differing from exposure
via
contaminated sediment, suggesting that exposure route also had a determining role in Ag bioavailability. The simulated aged form (Ag
2
S-NPs) revealed fast uptake and depuration in snails from all experiments. When considering the double exposure route, which provides a more realistic contamination scenario, water was the main route, except for Ag
2
S-NPs, for which sediment was more important. The remarkably low elimination and high stored fraction of Ag in some exposures emphasizes the bioaccumulation ability of
P. acuta
and may raise concerns about possible trophic transfer. Snail shells accumulated low amounts of Ag. The present study highlights the need for a proper examination of the overall exposure scenario of Ag-NPs to benthic organisms. Our results contribute to the environmental risk assessment of Ag-NPs in benthic environments.
Nanoparticle characteristics and exposure route greatly influence the toxicokinetics of pristine and (simulated) aged silver nanoparticles in
Physa acuta
.
Dental enamel consists mainly of calcium-deficient hydroxyapatite (CDHA). The formation and evolution of enamel is a progressive and complex process the final stage of which is post-eruptive ...maturation (PEM), when mineralisation is completed following tooth eruption and exposure to oral fluids. Although PEM is directly correlated with decrease in caries susceptibility, a complete model to describe the whole process does not exist. Several reports have recently suggested that the previously observed caries decline, which started with the introduction of F- in drinking water and dental products, has stopped and is in some cases in reverse. New research approaches are therefore needed, which will focus on caries prevention and not treatment. This project monitored the in vitro effects of simulated PEM on the physicochemical properties of dental enamel and proposed a model which describes the whole process. For this purpose, primary and permanent bovine enamel was tested, using a suitably designed demineralisation/remineralisation laboratory protocol as well as characterisation techniques. The results were applied to the synthesis of enamel proxies, which could mimic the physicochemical properties of dental enamel; these proxies were evaluated for their potential to be used as enamel substitutes in dental research.
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