Folic acid-conjugated core/shell ZnS:Mn/ZnS quantum dots as targeted probes for two photon fluorescence imaging of cancer cells.
Fiche publication
Date publication
mars 2011
Auteurs
Membres identifiés du Cancéropôle Est :
Pr SCHNEIDER Raphaël
Tous les auteurs :
Geszke M, Murias M, Balan L, Medjahdi G, Korczynski J, Moritz M, Lulek J, Schneider R
Lien Pubmed
Résumé
This work presents a novel approach to producing water soluble manganese-doped core/shell ZnS/ZnS quantum dots (ZnS:Mn/ZnS). The Mn-doped ZnS core was prepared through a nucleation doping strategy and a ZnS shell was grown on ZnS:Mn d-dots by decomposition of Zn(2+)-3-mercaptopropionic acid (MPA) complexes at 100 degrees C. It was found that the Mn2+(4)T1-->6A1 fluorescence emission at approximately 590 nm significantly increased after growth of the shell when the Mn2+ doping content was 4.0 at.%. A photoluminescence quantum yield of approximately 22% was obtained for core/shell nanocrystals. The nanoparticles were structurally and compositionally characterized by transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and dynamic light scattering. The surface MPA molecules favor the dispersion of ZnS:Mn/ZnS QDs in aqueous media and make possible conjugation with targeting folic acid molecules. The folate receptor-mediated delivery of folic acid-conjugated ZnS:Mn/ZnS QDs was demonstrated using confocal microscopy with biphotonic excitation. Bare and folate-conjugated QDs exhibit only weak cytotoxicity towards folate receptor-positive T47D cancer cells and MCF-7 cells, used as a reference, at high concentrations (mmolar range) after 72h incubation.
Référence
Acta Biomater. 2011 Mar;7(3):1327-38