Surface functionalization of two-photon dye-doped mesoporous silica nanoparticles with folic acid: cytotoxicity studies with HeLa and MCF-7 cancer cells
Two-photon dye-doped mesoporous silica nanoparticles (NPs) have been conjugated with folic acid (FA) in order to obtain efficient nanotools for bioimaging of cancer cells. The surface of the NPs was first functionalized with 3-aminopropyltriethoxysilane. The amine-covered NPs were subsequently reacted with an activated ester derivative of FA. Cytotoxicity studies performed with MCF7 and HeLa cancer cells demonstrate that these functionalized NPs are much less cytotoxic than the non-functionalized NPs against both cell lines. Unfortunately, the grafting of FA enables the formation of charge transfer complexes between the two-photon dye and FA which leads to quenching of the fluorescence of the NPs. Hence although these NPs cannot be used for biomaging purposes, they offer interesting potentialities if the two-photon dye used can be replaced by a two-photon fluorophore which do not interact with FA or if the interaction between the encapsulated dye and FA can be prevented by using a suitable spacer between the surface and the FA moiety.
KeywordsMesoporous nanoparticle Cancer cells Fluorescence Biphotonic MTT Charge transfer complex Chromophore
This project was sponsored by ACI nanobioscience NR 077. VL thanks CNRS and Region Languedoc Roussillon for a doctoral fellowship. The Rennes group acknowledges equipment grants from CNRS, Rennes Métropole and Université de Rennes 1. We thank David N’Guyen and Pr Etienne Duguet for potential Zeta measurements, kind and useful discussions. We thank Corine Gerardin for DLS Measurements.
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