In a study published in the February issue of Nature Biotechnology, the researchers report using quantum dots developed and manufactured by US-based company Quantum Dot to provide prolonged, real-time visualisations in living cells of the signalling mechanisms of the erbB family of receptors, the targets of many cancer drugs.
Quantum dots are nanoscale crystals of semiconductor material that glow in several different colours, depending on their size, when excited by a light source such as a laser.
The video-clip images mark the first time researchers have been able to see moving images of a cell's basic means of communication with its environment. The aim is that the technology will allow researchers to visualise how the signals generated when drugs bind to receptors are transferred to the interior of the cell, which will help guide them in designing drugs that interact with this process.
"The in vivo measurements reported in our study revealed new insights into cellular processes and interactions that could previously only be studied on fixed (dead) cells," according to the researchers, led by Thomas Jovin of the Max Planck Institute for Biophysical Chemistry in Goettingen, Germany.
Commenting on the study in an editorial appearing in the same issue of the journal, two scientists specialising in live cell imaging noted that QDC's nanocrystals "can track movements of individual receptors on the surface of living cells with unmatched spatial and temporal resolution."
Gal Gur and Yosef Yarden of the Weizmann Institute of Science in Rehovot, Israel, noted that other imaging methodologies - such as fluorescent dyes or polymer spheres - have limited spatial resolution and either require complex manipulation or fade too quickly, providing only very brief snapshots of receptor dynamics.