Nanotubes detect carcinogens in living cells
Researchers from the Massachusetts Institute of Technology, led by Michael Strano, have developed nanosensors that allow detecting single molecules of substances that damage DNA in living cells.
The technology is based on the ability of single-walled carbon nanotubes to fluoresce when illuminated with infrared light. The "highlight" of the method is that the nanotubes are covered with DNA molecules. Such a coating protects tissues from possible damage by nanotubes, and allows you to observe changes in the wavelength and / or intensity of the glow when DNA molecules are damaged by alkylating agents and other toxins, as well as free radicals, and by the nature of changes in fluorescence to identify the class of toxic agent and the degree of violations of the DNA structure.
The pictures show the cell before (on the left) and after the addition of hydrogen peroxide. The change in the nature of the glow is clearly visible.
The sensitivity of the sensor makes it possible to detect the action of single molecules of toxins and accurately determine the localization of DNA-damaging compounds in a living cell for a long time.
One of the possible applications of such sensors is monitoring the activity of both malignant and normal cells of anticancer drugs, for example, cisplatin, which kills tumor cells by alkylation of DNA – attachment to the nucleotides of methyl, ethyl and other monovalent hydrocarbon radicals.
The method can also be used to study the effect of drugs, carcinogens, reactive oxygen species and other toxic substances on healthy cells, as well as to test the effectiveness of drugs designed to protect DNA from damage. In particular, the researchers plan to use their method to study the effectiveness of various antioxidants, for example, contained in green tea.
The results of the work (Daniel A. Heller et al., Multimodal optical sensing and analyte specificity using single-walled carbon nanotubes) are published in the electronic version of the journal Nature Nanotechnology.
Portal "Eternal youth" http://www.vechnayamolodost.ru / based on MIT materials (Nanotubes sniff out cancer agents in living cells)
18.12.2008