Loofah sponge as an interface dressing material in negative pressure wound therapy: results of an in vivo study

Since the introduction of negative pressure wound therapy (NPWT), the physiological effects of various interface dressing materials have been studied. The purpose of this experimental study was to compare the use of loofah sponge to standard polyurethane foam or a cotton gauze sponge. Three wounds, each measuring 3 cm x 3 cm, were created by full-thickness skin excision on the dorsal sides of 24 New Zealand adult white rabbits. The rabbits were randomly divided into four groups of six rabbits each. In group 1 (control), conventional saline-moistened gauze dressing was provided and changed at daily intervals. The remaining groups were provided NPWT dressings at -125 mm Hg continuous pressure. This dressing was changed every 3 days for 9 days; group 2 was provided polyurethane foam, group 3 had conventional saline-soaked antimicrobial gauze, and group 4 had loofah sponge. Wound area measurements and histological findings (inflammation, granulation tissue, neovascularization, and reepithelialization) were analyzed on days 3, 6, and 9. Wound area measurements at these intervals were significantly different between the control group and study groups (P<0.05). Granulation and neovascularization scores were also significantly different between the control and treatment groups at day 3 (P=0.002). No differences in any of the healing variables studied were observed between the other three dressing materials. According to scanning electron microscopy analysis of the three interface materials, the mean pore size diameter of foam and gauze interface materials was 415.80±217.58 μm and 912.33±116.88 μm, respectively. The pore architecture of foam was much more regular than that of gauze. The average pore size diameter of loofah sponge was 736.83±23.01 μm; pores were hierarchically located--ie, the smaller ones were usually peripheral and larger ones werecentral. For this study, the central part of loofah sponge was discarded to achieve a more homogenous structure of interface material. Loofah sponge study results were similar to those using gauze or foam, but the purchase price of loofah sponge is lower than that of currently available interface dressings. More experimental, randomized controlled studies are needed to confirm these results.