Influence of gel matrix on wound healing activity of adhesive dressings filled with silver nanoparticles and humic acids applied for the rat burn model.

IM: to evaluate the therapeutic effectiveness of gels based on silver nanoparticles in combination with humic acids on healing of a thermal skin damage (burn wound) in rats. MATERIALS AND METHODS: In experiments on 57 white non-linear male rats weighing 218-260 g, the wound-healing effect of gels with a 10% composition of humic acids modified with nanosilver on various bases, prepared in a pharmacopoeial manner, was studied on a model of thermal skin burn of degree IIIB. The gel base used in 3 experimental groups was sodium salt of carboxymethylcellulose (Na-CMC, group Ia, n=12), polyacrylamide (PAAM, group Ib, n=12), polyethylene glycol (PEG, group I, n=12) . Laboratory animals in the comparison group (group II, n=12) received Levomekol ointment; in the control group (group III, n=8) no treatment was carried out. A thermal burn corresponding to degree III was applied to the proximal part of the back under general anesthesia using a thermal applicator with a flat working part in the shape of a circle with a diameter of 20 mm. 72 hours after the burn, the wound was freed from the scab by complete excision along the border with intact skin with the application of a splinting ring, after which the study drugs were applied. The dynamics of changes in the burn wound were assessed on days 10, 14, 17, 21, 24, 28 using the Universal Desktop Ruler program. RESULTS: It was found that the average time (median) for 75% epithelization of wounds in groups Ia, Ic, II was 29.4±0.2, 34 (33;34) and 33.3±0.45 days, while in Ib and III groups, the median time to 75% epithelization was not achieved. The healing index (%/day) for 28 days was 8.6, 4.8, 6.5, 6.1 and 4.4 in groups Ia, Ib, Ic, II and III, respectively. The dynamics of epithelization of thermal burns was most pronounced in group Ia, where Na-CMC acted as a gel base for humic substances modified with nanosilver. CONCLUSIONS: Based on the studies conducted, it can be concluded that the gel with the addition of nanosilver-modified humic substances based on Na-CMC has a wound-healing effect in case of thermal damage to the skin, superior to the effect of the reference drug “Levomekol” in terms of the healing time of burn wounds.