Studying nanotoxic effects of CdTe quantum dots in Trypanosoma cruzi

• Published in: Memórias do Instituto Oswaldo Cruz Vol. 106; no. 2; pp. 158 - 165
• Main Authors: Vieira, Cecilia Stahl, Almeida, Diogo Burigo, de Thomaz, André Alexandre, Menna-Barreto, Rubem Figueredo Sadok, dos Santos-Mallet, Jacenir Reis, Cesar, Carlos Lenz, Gomes, Suzete Araujo Oliveira, Feder, Denise
• Format: Journal Article
• Language: English
• Published: Brazil Fundação Oswaldo Cruz, Fiocruz 01-03-2011; Instituto Oswaldo Cruz, Ministério da Saúde; Fundação Oswaldo Cruz (FIOCRUZ)
• Subjects: Animals; Cadmium; Cadmium Compounds - toxicity; CdTe quantum dots; CdTe quantum dots - Trypanosoma cruzi - nanotoxicity; Cell Membrane - drug effects; Cell Proliferation - drug effects; Data processing; DNA damage; DNA Damage - drug effects; Flow Cytometry; Fluorescent Dyes; Mice; Microorganisms; Microscopy, Electron, Transmission; Mitochondria; Mitochondrial Swelling; nanotoxicity; Necrosis; Parasites; PARASITOLOGY; Plasma membranes; propidium iodide; Protozoa; Quantum Dots; Tellurium - toxicity; TROPICAL MEDICINE; Trypanosoma cruzi; Trypanosoma cruzi - drug effects; Trypanosoma cruzi - ultrastructure; nanotoxicity; CdTe quantum dots; Trypanosoma cruzi
• ISSN: 1678-8060; 0074-0276; 1678-8060; 0074-0276
• DOI: 10.1590/S0074-02762011000200007

Semiconductor nanoparticles, such as quantum dots (QDs), were used to
carry out experiments in vivo and ex vivo with Trypanosoma cruzi .
However, questions have been raised regarding the nanotoxicity of QDs
in living cells, microorganisms, tissues and whole animals. The
objective of this paper was to conduct a QD nanotoxicity study on
living T. cruzi protozoa using analytical methods. This was
accomplished using in vitro experiments to test the interference of the
QDs on parasite development, morphology and viability. Our results show
that after 72 h, a 200 μM cadmium telluride (CdTe) QD solution
induced important morphological alterations in T. cruzi, such as DNA
damage, plasma membrane blebbing and mitochondrial swelling. Flow
cytometry assays showed no damage to the plasma membrane when incubated
with 200 μM CdTe QDs for up to 72 h (propidium iodide cells),
giving no evidence of classical necrosis. Parasites incubated with 2
μM CdTe QDs still proliferated after seven days. In summary, a low
concentration of CdTe QDs (2 μM) is optimal for bioimaging,
whereas a high concentration (200 μM CdTe) could be toxic to
cells. Taken together, our data indicate that 2 μM QD can be used
for the successful long-term study of the parasite-vector interaction
in real time.