ИСТИНА

On the one hand carbonic acid is a very advantageous solvent for chemical engineering, because it is absolutely eco-friendly and there is no need to perform some time-consuming procedures like dialysis or washing out, because carbonic acid completely vanishes after decompression of the reactor and turns into a gas carbon dioxide and pure water. In the acidic conditions of carbonic acid we can construct micelles from block-copolymer, consisting of one polycationic block and one hydrophobic block, encapsulate metal nanoparticles in their corona and use them as renewable catalysts. Secondly, nowadays there is a huge problem with human hypersensitivity, therefore it would be very useful to find a media, which is absolutely biocompatible and, at the same time, can dissolve polymers suitable for different biomedical purposes. Carbonic acid combines two important properties due to which it appears to be very convenient solvent for biomedical applications. Those are strong antimicrobial activity at the stage of, for instance, coating formation on some medical device and remaining biocompatibility when using this device with the adsorbed coating in the human body. At the acidic conditions of carbonic acid biopolymer chitosan protonates, thus, as a result, chitosan becomes polycation and dissolves in such media. It is well known, that chitosan is capable of stabilizing Ag nanoparticles that are already reduced by other chemical agents. But we propose the one-step method for the formation of Ag nanoparticles from their salt in chitosan solutions in carbonic acid. Therefore some coatings and films for biomedical applications can be obtained from the solutions of dissolved biopolymer chitosan with antimicrobial silver nanoparticles in biocompatible carbonic acid.