Introduction: Nitric oxide (NO) is known to alter coagulation by regulating platelet activity and plays a role in immunological response, infection prevention, and wound repair. Thus, NO-generating coatings have a high potential for wound healing applications. This study selected plasma polymerization to deposit a thin coating because of its high speed and low temperature, controlled film thickness, versatility on various surfaces, and environmental friendliness. Plasma modification offers the unique advantage of selectively enhancing surface properties without affecting the bulk attributes of the materials.
Methods: Plasma surface modification was carried out by using the high-frequency plasma system ZP-COVANCE-RFPE-3MP operating at 13.56 MHz at 15 W. Isopentyl nitrite (99.995%), C2H4 (99.95%), and Ar (99.998%) were used as precursors to deposit thin films on silicon wafers and polycaprolactone nanofibers at a pressure below 30 Pa. The obtained plasma-deposited polymer films were studied using SEM, EDX analysis, XPS, FTIR spectroscopy, and WCA. The kinetics of the release of NO were investigated by means of spectrophotometry. The adhesion and proliferation of human fibroblast cells on the surface of plasma-treated samples were studied. The samples were tested against different pathogens in terms of biofilm formation.
Results: Plasma deposition resulted in homogeneous and well-bonded layers. SEM micrographs showed no pinholes, cracks, or other damage in the deposited layers. According to FTIR and XPS, the obtained spectra indicated the presence of nitroxyl compounds on the surface of the samples. The difference in wettability of the samples was determined to be ≈90⁰. The deposited polymer coatings were shown to promote better proliferation of human fibroblast cells. The plasma-treated samples completely prevented biofilm formation.
Conclusions: An approach was developed for the deposition of nitroxyl-containing films from a mixture of isopentyl nitrite/C2H4 with improved proliferation of human cells and high antipathogenic activity.
The research was funded by the Russian Science Foundation (№24-79-10121).
