Wound healing using ionic silver dressing and nanocrystalline silver dressing in rats

To investigate the results of the healing process on surgical wounds in the back of Wistar rats using nanocristaline and ionic silver dressing.

Sixty rats Wistar were submitted to surgical wounds with punch of 8 mm in diameter. In 30 animals (groups PN - nanocristaline and AD - control) two surgical wounds were done diametrically opposite on the upper back side. On the right side was used nanocristaline (PN) silver dressing and on the left side, distilled water dressing (AD). On the other group of 30 rats, only one wound was made with the punch, on the right side, and was used ionic silver dressing. So, the groups were divided into three subgroups, according to the day of death (7(th), 14(th) and 21(st) day). In each of these days the wounds diameter were measured to evaluate the wound contraction. Microscopic data were analyzed using the H&E staining to verify the inflammatory process and neovascularization. The Masson trichrome staining was used to verify the fibrosis.

Macroscopically only the subgroup of 21(st) day showed statistical significance; between the groups AD and PI inflammatory process appeared in the 7(th) day subgroup in 90% of the cases. In neovascularization there was statistical significance between the groups PN and AD in the subgroup of 7(th) day. Fibrosis did not show statistical significance in the studied groups.

In relation to wound contraction, PN and PI groups showed better results than the AD group. In regard to histological analysis, H&E staining showed that there was presence of inflammation in all groups, and at the end, the control group (AD) on 7(th) day, was superior to PN and PI groups. In relationship to fibrosis, no differences were obtained among groups.