Water-detecting nanodots single out cancer cells
doi:10.1038/nindia.2019.53 Published online 29 April 2019
Researchers have synthesised light-emitting nanodots that reveal how water is distributed inside biological cells1. These dots indicate that the distribution of water inside normal cells is different from that inside cancer cells – a finding that can help design a way to distinguish cancer cells from normal cells.
Intracellular water, which accounts for about 80 per cent of total cell mass, plays vital roles in the structural and functional relationship of biomolecules such as proteins, DNA and enzymes. Subtle changes in intracellular water may cause molecular dysfunction, resulting in cancer and neurological disorders.
To date, there are no suitable techniques to detect water inside normal and diseased cells. In search of a simple and efficient method, scientists from the Indian Institute of Technology in Himachal Pradesh, India, prepared the nanodots by heating common sugar and a specific organic compound.
The researchers, led by Chayan K Nandi, then explored the efficiency of the nanodots in detecting water inside normal and cervical cancer cells. Since the nanodots have water-attracting parts and water-repelling parts, they could organise themselves according to the nature of hydrogen bonds they form with water molecules. When bathed in near-ultraviolet light, the water-attached nanodots could emit light at far-ultraviolet wavelengths.
Exploiting such properties of the nanodots, the researchers showed that water contents are different in different parts of cells. The dots glowed only in the presence of water, uncovering the fact that the nuclei of cancer cells contain more free water than normal cells. The researchers say that this is the first probe to provide direct evidence of the hydrogen-bonding network in an entire cell.
1. Rao, C. et al. Unveiling the hydrogen bonding network of intracellular water by fluorescence lifetime imaging microscopy. J. Phys. Chem. C. 123, 2673-2677 (2019)