Technique to create an optimal capsule for targeted delivery of cancer drugs

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• Cancer (cancer)
• Cancer treatment

2022: Announcement of the methodology to create the optimal capsule for targeted delivery of cancer drugs

Employees of the Laboratory of Nano-Bioengineering of the Engineering and Physics Institute of Biomedicine NRNU MEPhI together with colleagues from Sechenov University and Reims University (France) conducted systematic studies specific functions of capsules affecting their interaction with components of biological fluids of a person, biodistribution in his body and efficiency of point delivery. This was announced on August 5, 2022 by representatives of the NRNU MEPhI.

Structural and functional properties of directed delivery systems and specific interaction with tumor cells based on polymer multilayer capsules.

Oddly enough, we were the first to raise the question of how the physicochemical properties of capsules affect their ability to deliver drugs. Whatever you add to the capsule, it will come to the tumor anyway for the simple reason that cancer cells are phagocytes, "eaters," they eat everything that gets to them. The whole question is in distribution and that the medicine gets there quickly and in large quantities, so that it spends as little time as possible in healthy tissues and does not harm them (since these drugs are toxic), and when it gets to patients, it would act most effectively. told by Professor Igor Nabiev

The capsule itself is only a platform, a vehicle, a kind of rocket carrier. But its structure is directly related to what will happen after the action of the drug. Therefore, it is necessary to select so components of polymers for the preparation of capsules so that they are biodegradable and excretable, that is, they would subsequently decompose harmlessly in the human body and leave no trace. The search for such a procedure for the preparation of polymer capsules took about a year: the selection of the optimal ratio of various physicochemical parameters is difficult analytical work.

The main identified factors affecting the operation of the capsule are its physicochemical properties: charge, size, homogeneity.

Choosing a charge is a matter of principle. If the surface charge is, for example, extremely positive or negative, then there will be a lot of non-specific in the action of the capsule, it will bind to the wrong cells, with with which it is necessary. Therefore, the charge must be chosen accurately, having a clear combination of polymers.

The optimal capsule size is about 1 micron. As it turned out, if you make it less, then the medicine, leaving the shell, will penetrate not only into the affected cells, but into healthy ones.

Homogeneity (size distribution) - all capsules should be approximately the same size, without large spread. This can be achieved by selecting, for example, the ionic force - the salt composition of the medium in which the capsule is prepared. Usually, salt ions, by binding to polymers that are used to prepare capsules, compact, compress them.

Chemistry in this situation decides everything. For example, biodegradability (decomposition) and shell permeability of such capsules (outward drug release rate and conditions) in a particular pH range depend on the use of certain polyelectrolyte polymers in the construction of the capsules. The tumor microenvironment is always acidic, unlike healthy cells, and, therefore, you need to create a capsule shell from such materials that "open" only at an acidic pH.

It is worth noting that the results of the study the Russian scientists were published by the journal of the Royal Chemical Society Great Britain Biomaterials Science.

As of August 2022, the IFIB nano-bioengineering laboratory is engaged in work to reduce the toxicity of capsules, to study their secondary effects on cell cultures (in vitro) and animals (in vivo). Clinical trials in humans so far are not carried out, but the speed of development of domestic scientific thought gives hope that an effective means of delivering antitumor drugs that does not reduce the patient's quality of life will be obtained in the coming years.