Toxicologie de nanoparticules métalliques à de faibles concentrations, pertinentes du point de vue environnemental

CNRS, UMR EPOC 5805Université de Bordeaux

Station marine d’Arcachon

par Jean-Paul Bourdineaudprofesseur, Université de Bordeaux

1er CONGRÈS SANTÉ-ENVIRONNEMENTOrganisé par l’URPS-Médecins libéraux de PACA

6 & 7 Décembre 2013Marseille - Palais du Pharo

Comment des nanoparticules peuvent-elles être introduites dans un système écologique ?

Quelle peut être l’ampleur de la pollution ?

Kaegi et al., Environmental Pollution, 156 (2008) 233-239

Fresh facade painting

Older facade painting

Collected particles from runoff events Concentration of micro and nanoparticles in rain runoffs

Les nanoparticules peuvent-elles être distribuées dans les différents compartiments d’un système écologique ?

Et si oui, quel est le niveau de transfert vers les différentes composantes biologiques ?

(Ferry et al.)

A single dose, 7.1 x 1011 of gold nanorods/L (65 x 15 nm), making 157 g Au NPs/L.

Genotoxic impact of metal nanoparticles on the zebrafish Danio rerio

Gold nanoparticles are used in pregnancy tests, toothpaste, energizing creams and beverages, detection and treatment of cancer tumours.Cadmium sulfide nanoparticles are used in electronic devices.

MesoGold, 20 ppm colloidal gold, 250 mL, by Purest ColloidsPrice: $29.97Fulfilled by Amazon (Gift-wrap).Supports mental focus & concentration, and improved hand/eye coordination.Promotes improved memory & a general feeling of well being.

Impact of cadmium sulfide and gold nanoparticles on the zebrafish

Controls

CdS (10 nm) CdS (50 nm) Au (12 nm) Au (50 nm)

Contamination through diet (5 µg nanoparticles/g food)giving 40 ng nanoparticles/fish/day

Exposure length: 60 days

100 nm 100 nm

Nanoparticles embedded in the food

12 nm NPs 50 nm NPs

Metal quantification (cadmium and gold) in zebrafish

tissues after 60 days of exposure.

Gold could not be quantified in tissues and even in whole fish.Detection limits by atomic absorption spectrometry :Cadmium : 0,1 µg/L Gold : 1 µg/L

 

Diet  Liver Brain Muscles Whole fish

Control food 8 ± 8 9 ± 0,9 0,6 ± 0,1 32 ± 8

CdS (10 nm) 348 ± 30 19 ± 3 1,8 ± 1 170 ± 10

CdS (50 nm) 364 ± 30 10 ± 3 3,1± 1 50 ± 5

Liver is the organ accumulating the most cadmiumThe little nanoparticles are more accumulated than the bigger in the brain and at the scale of the whole fish.

Total Cd in ng/g

Differential gene expression after 60 days of exposure

sod1 sod2 mt 2 rad 51 c-jun p53 bax pyc cox1

Liver

Au (12 nm) 1/18 1/381 1/71 1/10 1/27 1/45 1/20 1/9 1/12

Au (50 nm) / 1/28 / / 1/7 1/16 1/4 / /

CdS (10 nm) / 1/7 123 3 1/6 / 1/2 / 1/4

CdS (50 nm) 1/3 1/23 1/23 / 1/6 / 1/5 1/5 /

Brain

Au (12 nm) 2 3 3 2 38 20 8 26 1/9

Au (50 nm) / 5 / / 5 6 / 4 1/38

CdS (10 nm) / 2 25 / / 2 / 1/5 /

CdS (50 nm) 3 3 3 / 10 / 2 7 /

Muscle

Au (12 nm) / / / / 1/2 / / 9 /

Au (50 nm) / / / 1/3 3 / 1/3 1/6 1/16

CdS (10 nm) 5 10 20 32 6 12 4 / /

CdS (50 nm) / 0,4 / 2 / / / / 1/15

Oxidative stress Detoxication

DNA repair

General stress

Mitochondrial

metabolism

1/ CdS and gold nanoparticles trigger a different gene expression pattern.2/ Size does matter !

Control DNA Contaminated DNA

Pollutant

Probe OPB

OPBOPB

OPB

OPB

Loss of hybridization site

Principle of RAPD (Random amplified polymorphic DNA)

OPB

OPBOPB

OPB

Principle of RAPD (Random amplified polymorphic DNA)

OPB

OPBOPB

Control DNA

Creation of hybridization site

Contaminated DNA

Quantification of genotoxic damages by RAPD-PCR methodology

 RAPD probe Témoins CdS (10 nm) CdS (50 nm) Au (12 nm) Au (50 nm)

OPB70,6 ± 0,1 0,7 ± 0,1 * 6,5 ± 0,9 * 8,5 ± 0,9 * 1,9 ± 0,2

OPB11 (2,1 ± 0,7).10-5 * (31 ± 14).10-5 * (4300 ± 1800).10-5 * (5600 ± 1800).10-5 * (280 ± 70).10-5

1/ The numbers of hybridization sites for RAPD probes was modified by nanoparticles. 2/ The two metals presented different effects.3/ Size still matters !

Genomic DNAs were extracted from whole zebrafish individuals

Number of hybridization sites per genome of the RAPD probe

RAPD probes’ sequences:

OPB7 : 5’-GGTGACGCAG-3’OPB11 : 5’-GTAGACCCGT-3’

n = 10, mean ± SEM

Les nanoparticules piégées dans les sédiments aquatiques peuvent-elles être libérées dans la colonne d’eau et représenter un risque pour la santé des animaux ?

Impact of gold nanoparticles (14 nm) on zebrafish exposed to a spiked sediment

Brain AChE activity(nmol/mg/min)

Brain ache gene expression(relative to bactin gene)

440 ± 17 546 ± 8 551 ± 22

0.08 ± 0.01 0.10 ± 0.01 0.33 ± 0.05

Controls

Au (16 mg/kg)

Au (55 mg/kg)

Exposition : 20 days

0.25 g/L 0.8 g/L

Les nanoparticules incluses dans les sols peuvent-elles représenter un risque pour la santé des animaux ?

Metal nanoparticles trigger an oxidative stress in the earthworm Eisenia fetida

Silver nanoparticles are used as antibacterial and antifungal agents in textiles, water treatments, and medical devices.

Impact of gold and silver nanoparticles on the red earthworm

Contamination through the soilExposure length: 10 days

Controls

Gold NPs

Ionic gold

Silver NPs

Ionic silver

2, 10, and 50 mg/kg

2, 10, and 50 mg/kg

Lipid peroxidation and protein oxidation in earthworms exposed for 10 days to ionic and nanoparticular god and silver

Lipid peroxidation Protein carbonylation

MDA : malondialdehyde

CH2 CC

HH

OO

Counter-adaptive levels of catalase in earthworms exposed for 10 days to ionic and nanoparticular gold and silver

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0 mg/kg 2 mg/kg 10 mg/kg 50 mg/kg

CA

T (

mo

l min

-1 m

g-1

pro

tein

)

Au-NP Ag-NP Au Ag

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