Silver nanoparticles (AgNP), one of the main nanomaterials for production and use, are expected to reach the aquatic environment, representing a potential threat to aquatic organisms. In this study, the effects of bare AgNPs (47 nm) on the marine mussel Mytilus galloprovincialis were evaluated at the cellular and whole organism level utilizing both immune cells (hemocytes) and developing embryos. The effects were compared with those of ionic Ag+(AgNO3). In vitro short-term exposure (30 min) of hemocytes to AgNPs induced small lysosomal membrane destabilization (LMS EC50 = 273.1 µg/mL) and did not affect other immune parameters (phagocytosis and ROS production). Responses were little affected by hemolymph serum (HS) as exposure medium in comparison to ASW. However, AgNPs significantly affected mitochondrial membrane potential and actin cytoskeleton at lower concentrations. AgNO3 showed much higher toxicity, with an EC50 = 1.23 µg/mL for LMS, decreased phagocytosis and induced mitochondrial and cytoskeletal damage at similar concentrations. Both AgNPs and AgNO3 significantly affected Mytilus embryo development, with EC50 = 23.7 and 1 µg/L, respectively. AgNPs caused malformations and developmental delay, but no mortality, whereas AgNO3 mainly induced shell malformations followed by developmental arrest or death. Overall, the results indicate little toxicity of AgNPs compared with AgNO3; moreover, the mechanisms of action of AgNP appeared to be distinct from those of Ag+. The results indicate little contribution of released Ag+ in our experimental conditions. These data provide a further insight into potential impact of AgNPs in marine invertebrates.
Embryo, Nonmammalian/metabolism , Embryonic Development/drug effects , Hemocytes/cytology , Metal Nanoparticles/toxicity , Mytilus/cytology , Mytilus/embryology , Silver/toxicity , Animals , Cytoskeleton/drug effects , Cytoskeleton/metabolism , Embryo, Nonmammalian/drug effects , Hemocytes/drug effects , Hemolymph/drug effects , Larva/cytology , Larva/drug effects , Lysosomes/drug effects , Lysosomes/metabolism , Metal Nanoparticles/ultrastructure , Mitochondria/drug effects , Mitochondria/metabolism , Mytilus/drug effects , Phagocytosis/drug effects , Silver Nitrate/toxicity , Toxicity Tests , Water Pollutants, Chemical/toxicity
Gadolinium dioxycarbonates co-doped with different visible emitting lanthanides were synthesized via a co-precipitation method using oxalic acid as a precipitating agent. Through XRD and DTA/TG investigations, the type-II hexagonal phase of the lanthanide dioxycarbonates was confirmed for all of the samples. The materials constitute of big agglomerates formed by submicrometrical particles. By varying the Ln3+ doping percentages and ratios and by changing the excitation wavelength the gadolinium dioxycarbonates activated with Sm3+, Eu3+, Tb3+, Dy3+ and Tm3+ showed tunable emission colors. Luminescence measurements were performed in order to determine: the luminescence behavior of the ions, the CIE coordinates, the CCT values and potential energy transfer. Interesting results were achieved upon exciting the samples at 351 nm and 365 nm demonstrating the possibility to obtain white emission in the dioxycarbonate matrix.
