Theranostics in an MRI scanner
Scientists: due to MRI, it will be possible not only to diagnose, but also to treat cancer
Scientists of the National Research Nuclear University "MEPhI" have developed a new type of contrast agents for magnetic resonance imaging (MRI) based on biodegradable silicon nanoparticles that can be used simultaneously for both diagnosis and therapy of oncological diseases. The results of the study are published in the Journal of Applied Physics.
MRI is a powerful method of biomedical diagnostics, which usually uses nuclear magnetic resonance of hydrogen atoms (protons). During the operation of the tomograph, a magnetic field is created, which "builds" protons of hydrogen atoms in a magnetic field during exposure to radio waves.
Some studies require the use of contrast agents to increase the accuracy and informativeness of the image. The contrast signal in MRI depends mainly on the degree of change in the longitudinal or transverse relaxation time. The relaxation time is the time it takes for protons to return to an equilibrium state. It depends on the molecules and atoms surrounding the proton and is different in healthy and diseased tissues.
In some cases, pathology can be determined due to contrast agents that locally alter the relaxation times of the diseased tissue. The combination of MRI and contrast agents increases the possibilities of imaging inflammation, such as tumor angiogenesis in oncology.
MEPhI has developed a new type of contrast agent based on silicon nanoparticles, which allows combining therapy and diagnostics. According to Viktor Timoshenko, Professor of the IFIB of MEPhI and Lomonosov Moscow State University, this is an example of the development of nanoteranostics – a combination of diagnostic and therapeutic methods on a nanoscale scale.
Theranostic agents for MRI involve a combination of contrast agents with therapy, which is carried out by isolating nanocapsulated drugs and/or additional exposure to physical fields or radiation. "Since MRI is widely used in oncodiagnostics, the development of a new type of contrast agent, which can also be used for gentle therapy of oncological diseases, is very important for modern medicine," Viktor Tymoshenko says.
Nanoteranostics materials should be non-toxic and compatible with the human body. Another necessary property is "invisibility" for the immune system – otherwise it will simply destroy them. Also, nanoparticles should not accumulate in the body, and their surface should not be contaminated.
According to representatives of the Nanoteranostics Laboratory of the Engineering Physics Institute of Biomedicine (IFIB) The use of silicon nanoparticles to detect affected cells is one of the most promising methods of cancer nanoteranostics. Such nanoparticles themselves are not harmful to the body, but they can be heated to a temperature of 42 ° C or higher under the influence of radio waves (this is called hyperthermia), which ensures the local destruction of cancer cells.
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