title: Toxicological effects of CdSe/ZnS quantum dots on marine planktonic organisms.
abstract: Quantum dot nanoparticles (QDs) are proposed as novel materials for photovoltaic technologies, light emitting devices, and biomedical applications. In this study we investigated the effect of CdSe/ZnS QDs on the growth rate of four microalgae: the diatom Phaeodactylum tricornutum, the cryptophyte Rhinomonas reticulata, the prymnesiophyte Isochrysis galbana and the green alga Dunaliella tertiolecta. In addition we analyzed the effect of QDs on the copepod Acartia tonsa. A classical acute test (48-h) with embryos was carried out to evaluate naupliar survival. Moreover, a 4-day chronic test with adult copepods was conducted to evaluate their fecundity (embryos f(-1)day(-1)) and egg hatching success. QDs in the range from 1 to 4nM gradually inhibited the growth rate of P. tricornutum, I. galbana, R. reticulata and D. tertiolecta with an EC50 of 1.5, 2.4, 2.5 and 4.2nM, respectively. Acute tests with A. tonsa (QD concentration tested from 0.15 to 1.5nM) showed an increased naupliar mortality in response to QD treatment, exhibiting an EC50 of 0.7nM. Chronic test showed no negative effect on egg production, except on the last two days at the highest QD concentration (2.5nM). No significant reduction of the percentage of egg hatching success was recorded during the exposure. Toxicity assessment of QDs was also investigated at the molecular level, studying heat shock protein 70 gene expression (hsp 70). Our results indicate that hsp70 was upregulated in adults exposed 3 days to 0.5nM QDs. Overall, these results suggest that species unable to swim along the water column, like P. tricornutum and early hatched copepods, could be more exposed to toxic effects of QDs which tend to aggregate and settle in seawater.
authors.affiliation: ISPRA, Piazzale dei marmi 12, 57123 Livorno, Italy; CAISIAL, Università degli Studi di Napoli Federico II, Reggia di Portici, Via Università 100, 80055 Portici (NA), Italy; National Engineering Research Center of Marine Facilities Aquaculture, College of Marine Science and Technology, Zhejiang Ocean University, No.1 Haida South Road, Lincheng Changzhi Island, Zhoushan, Zhejiang 316022, PR China.
authors.forename: Chao
authors.initials: C
authors.lastname: Zhou
authors.affiliation: ISPRA, Piazzale dei marmi 12, 57123 Livorno, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Vitiello
authors.affiliation: ISPRA, Piazzale dei marmi 12, 57123 Livorno, Italy.
authors.forename: David
authors.initials: D
authors.lastname: Pellegrini
authors.affiliation: National Engineering Research Center of Marine Facilities Aquaculture, College of Marine Science and Technology, Zhejiang Ocean University, No.1 Haida South Road, Lincheng Changzhi Island, Zhoushan, Zhejiang 316022, PR China.
authors.forename: Changwen
authors.initials: C
authors.lastname: Wu
authors.affiliation: Istituto di Biofisica (CNR), Area della Ricerca di Pisa, Via Moruzzi 1, 56124 Pisa, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Morelli
authors.affiliation: ISPRA, Piazzale dei marmi 12, 57123 Livorno, Italy. Electronic address: isabella.buttino@isprambiente.it.
authors.forename: Isabella
authors.initials: I
authors.lastname: Buttino
mesh_terms: D000818:Animals; D001681:Biological Assay; D019187:Cadmium Compounds / Q000737:chemistry / Q000633:toxicity*; D000460:Chlorophyta / Q000187:drug effects / Q000502:physiology; D033342:Copepoda / Q000187:drug effects / Q000502:physiology; D017377:Diatoms / Q000187:drug effects / Q000502:physiology; D023381:Endpoint Determination; D005786:Gene Expression Regulation; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D058086:Microalgae / Q000187:drug effects / Q000502:physiology; D053758:Nanoparticles / Q000737:chemistry; D010933:Plankton / Q000187:drug effects* / Q000528:radiation effects; D045663:Quantum Dots / Q000737:chemistry / Q000633:toxicity*; D012623:Seawater / Q000737:chemistry; D018036:Selenium Compounds / Q000737:chemistry / Q000633:toxicity*; D013440:Sulfides / Q000737:chemistry / Q000633:toxicity*; D017967:Zinc Compounds / Q000737:chemistry / Q000633:toxicity*
chemical_list: D019187:Cadmium Compounds; D018840:HSP70 Heat-Shock Proteins; D018036:Selenium Compounds; D013440:Sulfides; D017967:Zinc Compounds; C058667:cadmium selenide; C031238:zinc sulfide
keywords: Acartia tonsa; Gene expression; Marine microalgae; Nanoparticles; Nanotoxicity