[Todos] Seminario INQUIMAE/DQIAyQF

[andrea en qi.fcen.uba.ar]

Lunes 22 de marzo 13 hs



Aula Seminarios INQUIMAE-DQIAQF

 Ciudad Universitaria Pab. II Piso 3°



"The toxicological Impact of Nanoparticles"



Dr. Roberta Brayner (Associate Professor)
NANOMATERIALS TEAM
Université Paris Diderot (Paris 7)
Interfaces, Traitements, Organisation et Dynamique des Systèmes - ITODYS-CNRS

To produce unique products with novel properties we need to manipulate
materials at the nanoscale level. In the word, man-made nanoparticles and
materials are being rapidly produced in large quantities and it was shown,
in the past ten years that nanomaterials have different toxicity profiles
compared with larger particles because of their small size and also their
high reactivity. In this moment, the toxicological and environmental
effects of direct or indirect exposure to these manufactured nanomaterials
are not completely elucidated. The physico-chemistry is essential to
understanding the fate and behavior of nanoparticles in the environment,
as well as uptake and distribution within organisms, and the interactions
of nanoparticles with other pollutants. It has been reported that when the
particle size decreases, there is a tendency to increase the toxicity,
even if the same material is relatively inert in bulk form (e.g. SiO2,
carbon black, TiO2, ZnO). The nanoparticles, due to their nanoscale, shape
and consequently huge surface area, may interact more efficiently with
biological systems producing important toxicity. In addition, the surface
area are directly correlated to many others physico-chemical properties
such as chemical reactivity, surface adsorption ability, surface charge,
etc. All these factors strongly dominate nanotoxicological behavior in
vivo. In addition, the toxicological impact of nanoparticles depends also
on the biological target used. In this new multi-disciplinary field, there
are many challenges ahead and some controversies, but knowledge transfer
from biology, toxicology, colloid chemistry, as well as material and
geological sciences, will enable to improve (nano)ecotoxicology studies.
The present work is focused on (i) the study of the physico-chemical
properties of some nanoparticles (TiO2, ZnO, CdS, Fe, CeO2, carbon
nanotubes) prepared without and with protective agents before and after
contact with the culture media and also (ii) the study of the ecotoxic
impact of these nanoparticles on microorganisms.