Dressing for diabetics
NUST MISIS scientists have developed bandages for the treatment of diabetic ulcers
MISIS Press Service
Innovative dressings based on organic polymers and silver nanoparticles that stimulate the healing of diabetic ulcers and chronic wounds were created by a scientific team of scientists from NUST MISIS and NIIKEL branch of ICIG SB RAS. The results of the work are published in the international scientific journal Pharmaceuticals (Permyakova et al., Ag-Contained Superabsorbent Curdlan–Chitosan Foams for Healing Wounds in a Type-2 Diabetic Mice Model).
With diabetes, the level of glucose in the blood remains high, this worsens the work of white blood cells — they cannot function normally, as a result, the body becomes particularly vulnerable to infections. In addition, diabetes affects blood circulation, making it difficult to deliver nutrients. This leads to slow healing of wounds, and also increases the likelihood of complications in the form of infection. Chronic wounds are also observed in patients with other metabolic disorders (kidney and liver diseases, tuberculosis, HIV/AIDS, etc.)
For the successful healing of chronic wounds or diabetic complications, it is necessary to provide several conditions: removal of excessive exudate (fluid released into the tissue during damage), providing access to the necessary amount of oxygen to the wound, creating a moist environment, maintaining sterility.
It is not possible to provide a combination of these conditions with modern means: according to statistics, 85% of surgical amputations were the result of diabetic foot ulcers. In most cases, therapy consists simply in replacing bandages, hydrogel patches are considered effective among the new approaches.
To solve this complex problem, a team of materials scientists from NUST MISIS used substances from the class of polysaccharides — organic polymers that can absorb and retain aqueous solutions hundreds of times their own dry weight.
"We took two substances as a basis. Chitosan is a well—known carbohydrate polymer derived from the chitinous coat of crustaceans, which has many potential clinical applications due to its antibacterial, anticoagulant, antitumor and hemostatic properties. Kurdlan is a homopolysaccharide from the category of β-glucans and has a positive effect on the human immune system, exerting antitumor and antimicrobial effects," said Elizaveta Permyakova, the author of the study, researcher at the Inorganic Nanomaterials laboratory of NUST MISIS.
By varying the temperature, heating time and concentration of polysaccharides, biomaterials of various strengths can be obtained. In their study, the developers synthesized a therapeutic agent in the form of foam based on chitosan and kurdlan. It was obtained by lyophilization — soft drying of the dissolved mixture, in which the dried preparation was frozen, and then placed in a vacuum chamber, where the solvent was removed.
"To enhance the antibacterial properties and stimulate the immune system, we added a silver nitrate solution to the kurdlan/chitosan mixture during polymerization, which was subsequently reduced to silver nanoparticles under UV irradiation. In vivo tests on mice with genetically determined type 2 diabetes mellitus revealed an increased effect of silver—modified foam: it significantly accelerates the regeneration process compared to pure foam and the control group," Elizaveta Permyakova added.
According to the authors, the resulting foamy substance has antibacterial and super-absorbent properties that allow the exudate to be localized in the form of a gel, provides good oxygenation of the wound surface and prevents bacterial infection. In addition, silver nanoparticles in the composition stimulate the immune system, which accelerates the healing process.
Currently, the team is completing tests of the obtained material in the framework of preclinical studies in vivo.
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