Cobra venom and quantum dots for oncosurgery
NUST MISIS scientists have learned how to effectively diagnose cancer using cobra venom and quantum dots
A group of researchers from the National Research Technological University "MISIS" together with colleagues from the University of Tezpur (India) synthesized a drug based on alpha neurotoxins derived from cobra venom and semiconductor fluorescent nanoparticles. The new drug is able to effectively "mark" the boundaries of a cancerous tumor in the body.
Early and reliable diagnosis of oncological diseases is one of the most popular areas of biomedical research. During surgical removal of malignant neoplasms, it is very important for doctors to see the boundaries of the operated area. The better the neoplasm zone is marked, the more effective the procedure will be.
NUST MISIS scientists, led by Professor Yuri Utkin, have developed a unique hybrid compound (conjugate) of two molecules with different properties – alpha neurotoxins derived from the venom of the Thai cobra, and fluorescent quantum semiconductor nanoparticles of cadmium selenide (so-called "quantum dots"). The resulting conjugates can be used to create medical test systems that visualize a number of oncological neoplasms.
The Indian side conducted a study of the cytotoxicity of alpha-neurotoxins, nerve growth factors, as well as their conjugates with fluorescent nanocrystals on cells of different types.
Snake venoms are complex mixtures of proteins with various types of biological activity. In particular, the poisons of cobras and mambas contain alpha-neurotoxins that interact with specific receptors and completely block the transmission of nerve impulses in the body (which is the basis for the paralyzing effect of venom when bitten by snakes).
The biological "targets" of alpha-neurotoxins are nicotine cholinergic receptors. These are specific groups of proteins that a cancerous tumor (for example, small cell lung cancer or breast cancer) produces in pathologically large quantities. In a healthy body, holinoreceptors are involved in conducting a nerve impulse.
To visualize the tumor, scientists decided to use a unique property of toxins – selective interaction with a certain "marker" of the disease. The coupling "neurotoxin-quantum dot" enters the affected organ with the bloodstream and marks the entire tumor area due to the bright fluorescence of nanoparticles. They are able to glow when exposed to UV radiation invisible to the eye.
"We synthesized conjugates of quantum dots with toxins using specially developed techniques that ensure the stability of the compounds obtained when injected into the body. Cadmium selenide nanoparticles are coated with a thin film of a peptide (short protein), which gives a high degree of biocompatibility of conjugates and allows neutralizing the toxicity of the quantum dots themselves. At the same time, the created conjugates have a significantly smaller size compared to analogues, which greatly facilitates the process of drug delivery to the organ," said Professor Yuri Utkin, project manager, expert at the NUST MISIS Center for Energy Efficiency. According to the scientist, the use of fluorescent nanoparticles can significantly increase the effectiveness of diagnostic studies, since they significantly exceed traditional labels in a number of parameters, having brighter fluorescence and high resistance to fading.
The resulting drug can also be used as a therapeutic agent with targeted delivery if a drug is attached to the conjugate molecule. As you know, in the treatment of oncological diseases, the most important task is precisely targeting the affected organ, since most of the drugs are toxic in nature.
Currently, the team of developers is optimizing the characteristics of the drug and preparing for preclinical studies of the samples obtained. In vivo trials are scheduled for the near future.
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26.12.2016