Collagen bilayer dressing with ciprofloxacin, an effective system for infected wound healing.

Bacterial wound infection is a major problem, which hinders the normal healing process. In this study, a collagen bilayer dressing with ciprofloxacin was prepared from succinylated type-I collagen; FT-IR spectroscopy, SEM analysis, in vitro drug release pattern, antimicrobial activity and in vivo efficacy of the dressing were studied. The healing pattern was analyzed on days 3, 5, 7, 14 and 21 by wound healing rate, bacterial population, biochemical and histological examinations of tissue samples. FT-IR spectra showed the succinylation of collagen and ionic binding of ciprofloxacin to succinylated collagen. SEM analysis showed uniform drug distribution in collagen sponge and in vitro drug release pattern showed a release profile for 3 days with effective drug concentration confirmed by zone of inhibition. Ciprofloxacin counter-acted the effect of invading bacteria, as could be seen by considerable reduction in total bacterial population of the wound. In vivo analysis showed significant wound closure, biochemical analysis, such as protein, DNA, hydroxyproline, SOD, catalase, hexosamine and uronic acid from the granulation tissue, showed enhanced healing in the group treated with collagen bilayer dressing with ciprofloxacin. Histological analysis and wound closure further confirmed proper healing. Our results suggest that sustained release of ciprofloxacin from a collagen bilayer dressing eliminates bacteria at the site of infection, leaving a pathogen-free wound environment, and it can be used as a dressing for an on-site delivery system.