New antibiotic-anesthetic modified release films. Preclinical evaluation on deep second degree burns

SANCHEZ MF; GUZMAN, ML; TOLEDO ME; LAINO C; SORIA, ELIO; OLIVERA, M.E.

Congreso; Reunión Anual de Sociedades de Biociencias; 2019

Most important burn treatment challengesare associated with control of infections and pain; and alsofunctional and aesthetic wound healing. The aim of this studywas to evaluate the wound healing efficacy in a burn rat model ofa treatment with an anesthetic-antibiotic polymeric films (AAF),compared to the reference treatment. A deep second degreeburn model was used in male Wistar rats (CICUAL UNLaRprotocol no 5/18). Each anesthetized animal was injured in thedorsal region with a metallic device (1 cm ø, 90 ± 2 oC, 30 sec).The AAF (Argentine Patent Application no 20190102232), controlfilm (CF) or reference cream treatments (RC: silver sulfadiazine1.0 %, lidocaine 0.67 % and vitamin A 248000 UI) were appliedonce daily for 21 days (n= 6). Control groups: untreated (UT)and not burned. Photographs and biopsies (H&E) were taken ondays 0, 7, 14 and 21. Epidermal continuity and dermalorganization were evaluated with scores according to Sanchez etal1. Biopsies analysis showed that epidermis closure was reachedin the order AAF > CF > UT > RC. Besides, burns treated withAAF presented complete dermis organization at day 21 andhistological characters similar to unburned control. These resultscould be related to the favorable moist environment provided bythe components of AAF, that positively impacts on the tissuerecovery. In contrast, burns treated with RC did not complete itsregeneration at day 21 and even a regression was observedrespect to day 14. Most of UT animals presented dense dermisand absence of skin annexes (day 21). These findings suggestthat the use of the AAF allowed a more rapid and better qualityskin regeneration process with respect to the available referencetreatment.