Cell Motility and Metastatic Potential Studies Based on Quantum Dot Imaging of Phagokinetic Tracks

A wide variety of eukaryotic cells are shown to engulf colloidal semiconductor nanocrystals, or quantum dots, when they migrate. Here we show that the uptake of the nanocrystals is directly correlated with the cell motility, by comparing in detail the motions of both cancerous and healthy human breast cancer cells, as well as several other cell types. The nanocrystals are more photochemically robust than organic dyes (which fade quickly) and do not perturb the cells. The ability to examine these behaviors in live cells over extended time periods, and to quantify changes in response to various molecular manipulations, provides a powerful tool for studying the processes of cell motility and migration – behaviors that are responsible for metastases of primary cancers.