Researchers from the NUST MISIS University in Russia have developed a novel therapeutic material based on polycaprolactone nanofibers modified with a thin-film antibacterial composition and plasma components of human blood. Biodegradable bandages made from these fibers could accelerate the growth of cells, contributing to the regeneration of damaged tissues, as well as preventing the formation of scars in cases of severe burns. The results of this study were published in Applied Surface Science (“Grafting of Carboxyl Groups Using CO2/C2H4/Ar Pulsed Plasma: Theoretical Modeling and XPS Derivatization”).
“The grafting of carboxyl groups enhances cell adhesion and can be used for immobilization of different biomolecules onto plasma-treated materials. The process, however, was not well optimized due to lack of clear understanding of the mechanisms of carboxylic group incorporation into plasma and their grafting to polymer surface. In this work the deposition of COOH plasma polymers from CO2/C2H4/Ar pulsed discharge has been studied depending on the gas mixture and duty cycle. We have demonstrated that the CO2/C2H4/Ar plasma with adjustable thickness of COOH functionalized layer and high stability of the grafted functions in water is a better solution for the COOH surface functionalization compared to the thoroughly analyzed CO2 plasma,” write the investigators.
“The concentration of different carbon environments and the density of COOH groups have been measured by using chemical derivatization combined with X-ray photoelectron spectroscopy. It has been found that the CO2/C2H4/Ar plasma mainly contains ester groups (COOC), the COOH/COOC ratio being between 0.03 and 0.08. The water stability of the COOH groups was significantly higher compared to ester environment, so immersing in water for 24 h allowed to increase the COOH/COOC ratio by a factor of 3. The mechanisms of the CO2 molecule attachment to hydrocarbon chains on the polymer surface and those located inside the plasma were modeled using ab initio calculations.”
Scar tissue mainly consists of irreversible collagen and significantly differs from the tissue it replaces, having reduced functional properties. For example, scars on skin are more sensitive to ultraviolet radiation, are not elastic, and the sweat glands and hair follicles are not restored in the area.
“The solution of this medical problem was proposed by the researchers from the NUST MISIS Inorganic Nanomaterials Laboratory, led by Anton Manakhov, Ph.D., a senior researcher. The team of scientists has managed to create multilayer bandages made of biodegradable fibers and multifunctional bioactive nanofilms, which [the bandages] prevent scarring and accelerate tissue regeneration,” said Alevtina Chernikova, rector of NUST MISIS.
“With the help of chemical bonds, we were able to create a stable layer containing blood plasma components (growth factors, fibrinogens, and other important proteins that promote cell growth) on a polycaprolactone base. The base fibers were synthesized by electroforming. Then, with the help of plasma treatment, to increase the material`s hydrophilic properties, a polymer layer containing carboxyl groups was applied to the surface. The resulting layer was enriched with antibacterial and protein components,” added Elizaveta Permyakova, one of the project members and laboratory scientists, who have already conducted a series of preclinical trials with the Research Institute of Experimental and Clinical Medicine.