Water-soluble pegylated quantum dots: from a composite hexagonal phase to isolated micelles.
We present a simple method based on the dispersion of fluorescent quantum dots (QD) into a liquid crystal phase that provides either nanostructured material or isolated QD micelles depending on water concentration. The liquid-crystal phase was obtained by using a gallate amphiphile with a poly(ethylene glycol) chain as the polar headgroup, named I. The hydration of QD/I mixtures resulted in the formation of a composite hexagonal phase identified by small-angle X-ray scattering and by polarized light and fluorescence optical microscopy, showing a homogeneous distribution of fluorescence within hexagonal phase. This composite mesophase can be converted into isolated QD-I micelles by dilution in water. The fluorescent QD-I micelles, purified by size exclusion chromatography, are well monodisperse with a hydrodynamic diameter of 20-30 nm. Moreover, these QD do not show any nonspecific adsorption on lipid or cell membranes. By simply adjusting the water content, the PEG gallate amphiphile I provides a simple method to prepare a self-organized composite phase or pegylated water soluble QD micelles for biological applications.
Boulmedais
F
F
Université de Rennes 1, Sciences Chimiques de Rennes, CNRS UMR 6226, Campus de Beaulieu, F-35042 Rennes Cedex, France.
Bauchat
P
P
Brienne
M J
MJ
Arnal
I
I
Artzner
F
F
Gacoin
T
T
Dahan
M
M
Marchi-Artzner
V
V
D004583:Electrons; D008055:Lipids / Q000737:chemistry; D008823:Micelles; D046529:Microscopy, Electron, Transmission; D015394:Molecular Structure; D011092:Polyethylene Glycols / Q000737:chemistry*; D045663:Quantum Dots; D012995:Solubility; D013057:Spectrum Analysis; D014867:Water / Q000737:chemistry*
D008055:Lipids; D008823:Micelles; D014867:Water; D011092:Polyethylene Glycols