Quantum dots with payload
Scientists create a universal "nanocurrier" for the medicine of the future
A nanoprobe for the point delivery of drugs to the affected tissues of the body was created by scientists of the National Research Nuclear University "MEPhI" (NRU MEPhI) as part of an international group. According to the authors, their development will help to create a universal means of targeted delivery of drugs for effective therapy of cardiovascular diseases, cancer, diabetes and a number of other pathologies. The article was published in the journal Nanomaterials (Linkov et al., Conjugates of Ultrasmall Quantum Dots and Acridine Derivatives as Prospective Nanoprobes for Intracellular Investigations).
Targeted delivery of drugs to certain tissues and cells is one of the most relevant areas in the treatment of focal diseases, including heart and vascular pathologies, cancer, tuberculosis, diabetes of both types and others, said the scientists of the MEPhI Research Institute.
This approach can be implemented through the use of nanoprobes – special structures capable of carrying a drug and special molecules that allow you to "target" the focus of pathology. The probe should be small in size, on the order of tens of nanometers, and at the same time have strictly defined physico-chemical properties and as little toxicity as possible.
As the scientists of the MEPhI Research Institute explained, the technologies for creating such systems in the world are in the early stages of development, so the key task now is to study the process of drug delivery. To do this, it is necessary that the movements of the probes in the body can be visualized in real time, for which special laser illumination is used.
According to the creators, all these conditions are met by a new superminiature probe developed by the staff of the Laboratory of Nano-Bioengineering (LNBI) MEPhI Research Institute in collaboration with other Russian scientists and researchers from France.
The new nanoprobe consists of a photoluminescent nanocrystal, the so–called quantum dot (CT), and molecules of acridine derivatives attached to its surface - drugs that help the probe to overcome the cell membrane. The advantages of this system over analogues, according to the creators, are much greater CT brightness at superminiature sizes.
Quantum dots in monocytes
"Quantum dots are fluorescent nanostructures used in some high–tech fields. They are able to absorb light in a wide range, and emit it in a narrow range determined by the size of the nanocrystal. That is, one or another quantum dot "glows" with a strictly defined color. These properties make CT almost an ideal tool for hypersensitive registration of biological objects in medicine," said the deputy head of the Laboratory of Nano–Bioengineering (LNBI) NRU MEPhI Pavel Samokhvalov.
The size of the new probe is only about 15 nanometers, which is hundreds and thousands of times smaller than human cells, the scientists said. The bright luminescence of CT allows using a directional laser beam to track the movements of the probe through the tissues of the body. A special polyethylene glycol shell with carboxyl end groups makes the nanoprobe biocompatible: as experiments have shown, thanks to this, it quickly accumulates in cells in the right volume.
"The new nanoprobe is intended primarily for experimental research in the development of targeted delivery tools for anti-cancer drugs. However, it is also a prototype of a universal tool of this kind," Pavel Samokhvalov explained.
Specialists from I.M. Sechenov First Moscow State Medical University, N.N. Blokhin National Medical Research Center of Oncology and Reims Champagne-Ardennes University took part in the study.
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