Intracellular Trafficking and Distribution of Cd and InP Quantum Dots in HeLa and ML-1 Thyroid Cancer Cells

Abstract

The study of the interaction of engineered nanoparticles, including quantum dots (QDs), with cellular constituents and the kinetics of their localization and transport, has provided new insights into their biological consequences in cancers and for the development of effective cancer therapies. The present study aims to elucidate the toxicity and intracellular transport kinetics of CdSe/ZnS and InP/ZnS QDs in late-stage ML-1 thyroid cancer using well-tested HeLa as a control. Our XTT (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) viability assay (Cell Proliferation Kit II) showed that ML-1 cells and non-cancerous mouse fibroblast cells exhibit no viability defect in response to these QDs, whereas HeLa cell viability decreases. These results suggest that HeLa cells are more sensitive to the QDs compared to ML-1 cells. To test the possibility that transporting rates of QDs are different between HeLa and ML-1 cells, we performed a QD subcellular localization assay by determining Pearson’s Coefficient values and found that HeLa cells showed faster QDs transporting towards the lysosome. Consistently, the ICP-OES test showed the uptake of CdSe/ZnS QDs in HeLa cells was significantly higher than in ML-1 cells. Together, we conclude that high levels of toxicity in HeLa are positively correlated with the traffic rate of QDs in the treated cells.

Interactions between Quantum Dots and G-Actin

“…According to the manufacturer, this quantum dot product has an emission peak of 620-635 nm. Previously, Zhang et al (our lab) measured an air-dry diameter of around 5-10 nm and a hydrodynamic diameter of 20 nm [84]. These numbers were consistent with the manufacturer's provided information.…”

“…These are proteins that are associated with transcription, translation, mitochondrial function, and vesicular trafficking. QD treatment has previously been shown to have a negative impact on many cellular processes and components, especially vesicular trafficking and mitochondrial function [39,67,[83][84][85][86][87][88][89]. Thus, future research that focuses on the interaction between these proteins with QDs and its impact on protein structure and function may open a novel aspect to learning about QD toxicity.…”

Quantum dots and their potential biomedical applications

“…Moreover, scientists found that mammalian cell lines could uptake the QDs efficiently. QDs are targeted to different cellular organelles [28][29][30]. According to these mentioned features, QDs show their potential in drug delivery.…”

Current Advances in the Biomedical Applications of Quantum Dots: Promises and Challenges

“…Simultaneously, QDs’ fluorescence is easily detectible, allowing researchers to clearly map the drug distribution process of QD-derived delivery complexes. Moreover, it was found that QDs are easily taken up by various mammalian cell lines and are targeted to different cellular organelles, including the lysosome [ 114 , 115 , 116 , 117 ]. This feature of QDs ensures that QD-derived drug delivery systems are able to enter targeted cells and use the acidic environment in acidic organelles to dissociate therapeutic drugs from the delivery vehicle.…”