Theranostics against heart attack
Nanoparticles for targeted delivery of heart attack drugs have been obtained
Blog of SPbSETU "LETI", Naked Science
Today, one of the most promising alternatives for conventional pharmacological therapy of dangerous diseases, such as cancer or myocardial infarction, is targeted delivery of medicines and diagnostic tools or theranostics. The approach provides transportation of drugs to a given area of the body, a separate organ, and even cells using biotechnological products, for example, nanoscale capsules and particles.
At the same time, due to the relatively high accuracy, theranostics allows to quantitatively reduce the dose of drugs needed for treatment, and in the case of toxic drugs to reduce the overall load on the body. However, so far the level of technology development does not allow to introduce this method into a wide medical practice. Therefore, now specialized research teams in different countries are developing various types of theranostic platforms.
"In our study, multilayer nanoparticles were obtained for the diagnosis and targeted delivery of drugs for myocardial infarction. As a medicine, we used a well—known pharmacological compound - quinacrine, in which scientists have recently discovered cardioprotective properties. Preclinical tests of the platform were carried out on rodents," says Maria Istomina, a graduate student of the Department of MNE of SPbSETU "LETI", a junior researcher at the Research Laboratory (NIL) of Nanotechnology of the Almazov National Research University.
Multilayer nanoparticles with a size of no more than 200 nanometers were synthesized on the basis of two types of compounds: silica (SiO 2) and magnetite (Fe 2 O 3), which were obtained by the sol-gel method. Modification of nanoparticles was carried out in a flask (at a temperature of 80 degrees) by sequentially applying four layers: an organic molecule (spacer), to which quinacrine was "attached". Then the cardioprotector was covered with another layer of spacer, on which a green fluorophore and colloidal quantum dots were placed — these compounds are used as a marker for visual detection of nanoparticles.
After that, the scientists began conducting experiments. To begin with, rodents with myocardial infarction were intravenously injected with nanoparticles in the form of an aqueous suspension. Due to the fact that healthy and damaged heart tissue have different permeability parameters, over time, nanoparticles gradually began to get stuck and concentrate in the infarction area.
With the help of a fluorescent tomograph, the researchers managed to "highlight" the place of accumulation of particles and thereby localize myocardial infarction. Moreover, scientists were able to identify nanoparticles during experiments in a test tube, as well as in the rodent's heart muscle and throughout the body. After the diagnosis, the nanoparticle shells consisting of an organic spacer dissolved within a few days, and the cardioprotector began to act. The results of the study are published in the International Journal of Molecular Sciences (Korolev et al., Theranostic Platforms Based on Silica and Magnetic Nanoparticles Containing Quinacrine, Chitosan, Fluorophores, and Quantum Dots).
"Our experiments have shown a positive effect from the use of this theranostic platform for the treatment of such a severe and massive disease as myocardial infarction – we have recorded a decrease in its size and a decrease in the anatomical risk zone in rodents," says Dmitry Korolev, head of the Nanotechnology Research Institute of the Almazov National Research Medical Center.
Scientists plan to experimentally compare the effectiveness of the obtained nanoparticles with analogues that are being developed by leading scientific groups in the United States and China. The team of authors included employees of the Research Institute of Nanotechnology of the Almazov National Research University, leading researcher, Candidate of Technical Sciences, Associate Professor, Postnov V. N., junior researcher Shulmeister G. A., Professor and corresponding member of the Russian Academy of Sciences, MD Galagudza M. M. and others. In general, the researchers' work is aimed at developing a theranostic platform, which in the future may become sufficiently technologically advanced for mass production.
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