Nanosilver Environmental Safety in Marine Organisms: Ecotoxicological Assessment of a Commercial Nano-Enabled Product vs an Eco-Design Formulation

Abstract

With the increasing use of manufactured nanomaterials in consumer products, especially silver nanoparticles (AgNPs), concerns about their environmental impact are rising. Two AgNP formulations were tested, the commercial nanosilver product nanArgen™ and a newly eco-designed bifunctionalized nanosilver (AgNPcitLcys), using marine organisms across three trophic levels, microalgae, microcrustaceans, and bivalves. Acute toxicity was assessed on the diatom Phaeodactylum tricornutum, brine shrimp larvae Artemia franciscana, and bivalve Mytilus galloprovincialis. The behavior of the formulations in marine media, including stability across a concentration range (0.001-100 mg/L), was also evaluated. Results showed that nanArgen™ was less stable compared to AgNpcitLcys, releasing more silver ions and exhibiting higher toxicity to microalgae (100% growth inhibition at 1 mg/L) and microcrustaceans (>80% mortality at 10 mg/L). Conversely, AgNPcitLcys (10 µg/L) was more toxic to bivalves, possibly due to the smaller nanoparticle size affecting lysosomal membrane stability. This study highlights how eco-design, such as surface coating, influences AgNP behavior and toxicity. These findings emphasize the importance of eco-design in minimizing environmental impacts and guiding the development of safer, more sustainable nanomaterials.

Keywords: capping; eco-design; ecotoxicology; nano-enabled products; silver nanoparticles.

Figure 1

Ag concentration (µg/L) in (A) F/2 and (B) NSW upon incubation of AgNPcitLcys and nanArgen™ at, respectively, 0, 1, 5, 10, 100, 500, and 1000 µg/L and 0, 0.1, 1, 10, and 100 mg/L of AgNPs. Results for 1 h of incubation (T1), 72 h of incubation for F/2, and 48 h of incubation for NSW (T2). Data shown as mean ± standard deviation.

Figure 2

(A) 72 h growth inhibition test of AgNPcitLcys (yellow), nanArgen™ (blue), and AgNO₃ (gray) at 0, 1, 5, 10, 100, and 1000 µg/L with P. tricornutum; (B) 48 h mortality test of AgNPcitLcys (yellow), nanArgen™, (blue) and AgNO₃ (gray) at 0, 0.1, 1, 10, and 100 mg/L with A. franciscana. Data shown as mean ± standard deviation.

Figure 3

A. franciscana specimens after 48 h of exposure to (A) CTRL, (B) 100 mg/L of AgNO₃, (C) 100 mg/L of AgNPcitLcys, and (D) 100 mg/L of nanArgen™.

Figure 4

(A) NRRT expressed as % of destabilized cells of mussels exposed to 100 µg/L of AgNPcitLcys, nanArgen™, and AgNO₃. Values are expressed as means ± SD out of 100 hemocytes scored. Asterisks above the bars show significant differences with control groups at each time point (* p < 0.05; ** p < 0.01). (B) P-gp efflux activity in gills of mussels exposed to 100 µg/L of AgNPcitLcys, nanArgen™, and AgNO₃. Verapamil (VER, 1 µM) is shown as the positive control. Data shown as fold variation in RhB content compared to controls. Asterisks on the above the bars show significant differences with the respective control groups (* p < 0.05; ** p < 0.01).