Effect of corticosteroid-antibiotic agents on granulation tissue in a murine model

Abstract

Objective: To compare the effects of 3 commonly used ototopical corticosteroid-antibiotic agents, currently available for use in the treatment of inflammatory conditions of the external and middle ear, on granulation tissue in an established murine model of wound healing. Subjects: Twelve C57/BL6J mice. Design: Eight-millimeter wounds, created bilaterally on the dorsum of the mice, were treated with combinations of 0.3% ciprofloxacin and 0.1% dexamethasone (CiproDex), 0.3% tobramycin and 0.1% dexamethasone (TobraDex), 0.2% ciprofloxacin hydrochloride and 1% hydrocortisone (Cipro HC), or phosphate-buffered saline (n = 6 each) for 3 days (days 4-6) and then harvested on day 7. Wound sections were stained with hematoxylin-eosin, Gomori trichrome, and CD31. Extracellular matrix deposition was graded from 1-4, and neovascularization was assessed by counting the number of endothelial-lined vessel lumens per high-power field (HPF). Results: The mean ± SEM grade of extracellular matrix deposition was lower in CiproDex- (1.7±0.2) and TobraDex- (2.0±0.2) but not Cipro HC-(2.9±0.3) treated wounds compared with control wounds (2.9±0.2) (P