Cytotoxicity of cadmium-containing quantum dots based on a study using a microfluidic chip

Abstract

There is a lack of reliable nanotoxicity assays available for monitoring and quantifying multiple cellular events in cultured cells. In this study, we used a microfluidic chip to systematically investigate the cytotoxicity of three kinds of well-characterized cadmium-containing quantum dots (QDs) with the same core but different shell structures, including CdTe core QDs, CdTe/CdS core–shell QDs, and CdTe/CdS/ZnS core-shell-shell QDs, in HEK293 cells. Using the microfluidic chip combined with fluorescence microscopy, multiple QD-induced cellular events including cell morphology, viability, proliferation, and QD uptake were simultaneously analysed. The three kinds of QDs showed significantly different cytotoxicities. The CdTe QDs, which are highly toxic to HEK293 cells, resulted in remarkable cellular and nuclear morphological changes, a dose-dependent decrease in cell viability, and strong inhibition of cell proliferation; the CdTe/CdS QDs were moderately toxic but did not significantly affect the proliferation of HEK293 cells; while the CdTe/CdS/ZnS QDs had no detectable influence on cytotoxicity with respect to cell morphology, viability, and proliferation. Our data indicated that QD cytotoxicity was closely related to their surface structures and specific physicochemical properties. This study also demonstrated that the microfluidic chip could serve as a powerful tool to systematically evaluate the cytotoxicity of nanoparticles in multiple cellular events.

The distribution and degradation of radiolabeled superparamagnetic iron oxide nanoparticles and quantum dots in mice

“…Since many Qdots contain cadmium or other toxic elements, the release of potential toxic metals is a major concern with respect to biosafety. Many studies have demonstrated the toxicity of various Qdots in cell culture [7][8][9][10][11][12]. However, when dosing was applied under physiological conditions in mice and rats, no abnormal behavior or tissue damage was observed over the period of months after systemic administration of Qdots [13][14][15].…”

Chip based single cell analysis for nanotoxicity assessment

“…Zheng et al 81 evaluated cytotoxicity of cadmium containing quantum dots on multicellular (HEK293 cells) events using microfluidic chip with fluorescent microscope. In another study by Hosokawa et al 82 , microfluidic chip based high throughput single cell array device was developed to study the gradient generated cytotoxic effect of toxin.…”

Evaluation of biological activity of quantum dots in a microsystem

“…The advantages of microfluidics include reduced reagent consumption and analysis time, ease of integration, and the potential for parallel processing and high‐throughput analysis. A microfluidic chip can accomplish lots of tasks in a single device, including sample mixing, reaction, separation, and detection . Microfluidic systems allow for an integration of many chemical and physical processes; therefore, they offer useful features for in vitro cell studies.…”

“…It should be stressed out that there is still a lack of reliable nanotoxicity assays available for monitoring and quantifying of multiple cellular events in cultured cells . A typical method used for observation and analysis of cellular events is flow cytometry, but its application is limited to nonadherent cells .…”