Wound healing using ionic silver dressing and nonocrystalline silver dressing in rats Cicatrização de feridas em ratos utilizando curativos com prata iônica e nanocristalina

PURPOSE: To investigate the results of the healing process on surgical wounds in the back of Wistar rats using nanocristaline and ionic silver dressing. METHODS: Sixty rats Wistar were submitted to surgical wounds with punch of 8mm 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 (7th, 14th and 21st 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. RESULTS: Macroscopically only the subgroup of 21st day showed statistical significance; between the groups AD and PI inflammatory process appeared in the 7th day subgroup in 90% of the cases. In neovascularization there was statistical significance between the groups PN and AD in the subgroup of 7th day. Fibrosis did not show statistical significance in the studied groups. CONCLUSIONS: 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 7th day, was superior to PN and PI groups. In relationship to fibrosis, no differences were obtained among groups.OBJETIVO: Investigar os resultados da cicatrização de feridas cirúrgicas em dorso de ratos, utilizando curativos de prata nanocristalina e iônica. MÉTODOS: Sessenta ratos Wistar foram submetidos à feridas cirúrgicas com punch de 8mm de diâmetro. Foram confeccionadas duas lesões diametralmente opostas nos animais dos grupos prata nanocristalina (PN) e controle água destilada (AD). Na lesão do lado direito foi utilizado curativo com prata nanocristalina e na do lado esquerdo curativo com água destilada. No outro grupo de 30 ratos, apenas foi realizada uma lesão com o punch no lado esquerdo e curativo com prata iônica. Os grupos foram divididos em subgrupos conforme o dia da morte (7º, 14º e 21º dias), o que caracterizou a existência de três subgrupos, nos quais foram tomadas as medidas do centro das lesões para estudar macroscopicamente a contração da ferida Microscopicamente foi utilizada a coloração H&E, através da qual foi observado o processo inflamatório e a neovascularização. Com a coloração Tricômio de Masson, foi estudada a fibrose. RESULTADOS: Macroscopicamente apenas o subgrupo 21 dias apresentou significância estatística entre os grupos AD e prata iônica (PI), porém quando comparados os dias de avaliação, dois a dois, dentro de cada tratamento, todos os subgrupos apresentaram significância estatística (p