Probing the cytotoxicity of CdSe quantum dots with surface modification

The cytotoxicity of CdSe quantum dots (QDs) with surface modification was reported first in the paper. CdSe QDs were incorporated into poly (D, L) lactide (PLA) nanoparticles and then surface modified with Fluronic (R) 68 (F-68), cetyltrimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS), respectively. Three different particle sizes and zeta potential of the surface modified CdSe QDs were produced using a nano-precipitation method. The cytotoxicity of the surface modified CdSe QDs was evaluated in HepG2 cell model with MTT viability assay. The results showed that the cytotoxicity of the surface modified CdSe QDs in vitro was dependent on the surface properties. Surface modification with F-68 and SDS could lessen the cytotoxicity of CdSe QDs, while surface modification with CTAB showed significant cell damage. CdSe QDs surface modified with F-68 were injected into mice and the fluorescence images in viscus were obtained. The results suggested that CdSe QDs surface modified with F-68 have low cytotoxicity and good potential for biological labeling and imaging applications. (c) 2006 Elsevier B.V. All rights reserved.