Evaluation of Quantum Dot Cytotoxicity Based on Intracellular Uptake

Abstract

Nanoparticles, such as quantum dots (QDs), composed of biologically toxic materials degrade in highly oxidative environments. Varying the QD surface coating significantly affects the intracellular uptake of QDs. Although the addition of PEG does not alter the inherent QD cytotoxicity, we demonstrate that the improved biocompatibility due to PEG-substitution arises from decreased intracellular uptake, which allows for biological applications of QDs with minimal toxicity. The image shows the live/dead reagent stain used to quantitate cytotoxicity. PEG: poly(ethylene glycol).