A team of scientists from Novosibirsk State Technical University (NETI) led by Ekaterina Litvinova, Candidate of Biological Sciences, is working on the creation of chitosan—based cryogels, gels with a highly porous structure and improved absorbing properties. The project to study the properties of biogels in their various modifications is part of the biomedical direction of the Priority 2030 program, implemented at NSTU-NETI.
"If a conventional hydrogel contains pores several hundred micrometers in size, then cryogel forms a highly porous structure with an abundance of pores ranging in size from 10 to 30 micrometers. A large number of pores makes it possible to obtain the maximum surface area, which improves the adsorption properties. The technology for creating cryogel is as follows: the polymer swells in solution, then the solution is frozen and kept at low temperatures for a certain time until water is removed from the frozen sample. We have determined how much cryogel needs to be kept in the cold to achieve an optimal ratio of parameters such as swelling, number and pore size," said Alexander Drannikov, PhD, Associate Researcher at the Center for Technological Excellence at NSTU-NETI.
The scope of cryogels is extensive, from medicine to agriculture. They can be used for water purification, in crop production for loading pesticides, antiviral agents and applying them to the soil, for targeted drug delivery to the body (for example, to deliver probiotics directly to the intestine), as well as for alcohol and food poisoning, since chitosan has structural features that effectively trap toxins and remove they are eliminated from the body.
As Alexander Drannikov notes, due to the developed surface, cryogels can absorb and release a large amount of moisture, and from the point of view of maintaining the water balance, they are more effective than hydrogels. By using different chitosan derivatives, cryogel can be modified by "sewing" different chemical groups to it and, thus, increasing its selectivity (selectivity to specific pollutants or toxins).
Cryogels, like other types of gels, do not require additional disposal measures and are safe for the environment: after fulfilling their intended purpose, they naturally decompose without causing any harm to the environment.
Currently, scientists are working to ensure the reproducibility of the cryogel creation process — to ensure that they have the same properties from batch to batch. In parallel, the development is already being tested as part of products for greenhouse complexes. The plans for the next year are to start scaling up the production of cryogels.