An article published in the journal “Nature Communications” describes a new technology developed to obtain highly detailed images at very small scales of what happens inside living cells. A team of researchers combined the use of heavy water as a tracer with the technique known as stimulated Raman scattering to be able to obtain images of metabolic activities. The idea is to use it for medical purposes, completing other exams, and biological research.
Various examinations such as magnetic resonance and PET can provide non-invasive metabolic information and are useful for various types of medical diagnosis, however they have some limitations. In order to overcome them, a team of researchers at Columbia University developed a type of exam that can show details that were previously impossible with the normal techniques in use.
Heavy water, in which deuterium replaces the most common hydrogen isotope, is already used sometimes as a tracer in certain types of analysis but in this case it was used together with the stimulated Raman scattering (SRS) technique, which allows to create a laser scan. Humans can tolerate small amounts of heavy water, which is incorporated into proteins, lipids and DNA, where deuterium forms chemical bonds with carbon.
The new technique is based on the fact that those bonds vibrate at variable frequencies when they’re hit by light, allowing to identify the type of molecule because each of them has a sort of chemical signature. An SRS laser makes it possible to generate those vibrations, which can be recorded in microscopic details.
By testing this technique that combines SRS lasers and deuterium as a marker, the researchers observed that brain cells in developing mice rapidly put on fat in a process called myelination. The image (Courtesy Min lab/Columbia, all rights reserved) shows to the right right mouse brain cells of 5 days with no myelination and to the left mouse brain cells of 11 days with myelination. The ability to detect normal and abnormal myelination could help detect head injuries and monitor the progression of multiple sclerosis.
There are many other possibilities of using this technique, from the detection of internal injuries to metabolic and development diseases up to the early detection of tumors. Precisely identifying cancer cells would help find ways to target them more effectively and with fewer side effects. Basically, in the coming years there could be a new tool for biological research and for medical examinations.
