Hemmila MR, Mattar A, Taddonio MA et al.Topical nanoemulsion therapy reduces bacterial wound infection and inflammation after burn injury. Surgery 148:499-509

Department of Surgery, University of Michigan Medical School, Ann Arbor, MI 48109-5033, USA.
Surgery (Impact Factor: 3.38). 02/2010; 148(3):499-509. DOI: 10.1016/j.surg.2010.01.001
Source: PubMed


Nanoemulsions are broadly antimicrobial oil-in-water emulsions containing nanometer-sized droplets stabilized with surfactants. We hypothesize that topical application of a nanoemulsion compound (NB-201) can attenuate burn wound infection. In addition to reducing infection, nanoemulsion therapy may modulate dermal inflammatory signaling and thereby lessen inflammation following thermal injury.
Male Sprague-Dawley rats underwent a 20% total body surface area scald burn to create a partial-thickness burn injury. Animals were resuscitated with Ringer's lactate solution and the wound covered with an occlusive dressing. At 8 hours after injury, the burn wound was inoculated with 1 x 10(6) colony-forming units (CFUs) of Pseudomonas aeruginosa. NB-201, NB-201 placebo, 5% mafenide acetate solution, or 0.9% saline (control) was applied onto the wound at 16 and 24 hours after burn injury. Skin was harvested 32 hours postburn for quantitative wound culture and determination of inflammatory mediators in tissue homogenates.
NB-201 decreased mean bacterial growth in the burn wound by 1,000-fold, with only 13% (3/23) of animals having P. aeruginosa counts greater than 10(5) CFU/g tissue versus 91% (29/32) in the control group (P < .0001). Treatment with NB-201 attenuated neutrophil sequestration in the treatment group as measured by myeloperoxidase assay and by histology. It also significantly decreased levels of proinflammatory cytokines (interleukin [IL]-1beta and IL-6) and the degree of hair follicle cell apoptosis in skin compared to saline-treated controls.
Topical NB-201 substantially decreased bacterial growth in a partial-thickness burn model. This decrease in the level of wound infection was associated with an attenuation of the local dermal inflammatory response and diminished neutrophil sequestration. NB-201 represents a novel potent antimicrobial and anti-inflammatory treatment for use in burn wounds.

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    • "Bacterial suspensions were diluted with 0.9% sterile saline, and the final concentrations were 1 × 106 colony-forming units per 100 μL. The rats then received a topical application of 1 × 106 colony-forming units of both S. aureus and E. coli in 100 μL and were left for 24 hours for infection to develop.25 All rats were divided into three groups, ie, three rats in group A, six rats in group B, and three rats in group C. The electrospun NDEM (PLGA/ collagen matrix) was applied to the infected wounds of each rat in group A, while the DEM (PLGA/collagen/antibiotic) was applied to the infected wounds of each rat in group B. The rats in group C were treated with conventional gauze sponge as the control. "
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