Preliminary assessment of photoactivated antimicrobial collagen on bioburden in a murine pressure ulcer model.
Photomed Laser Surg
; 31(11): 539-46, 2013 Nov.
Article
em En
| MEDLINE
| ID: mdl-24138191
ABSTRACT
OBJECTIVE AND BACKGROUND DATA Overcoming bacterial antibiotic resistance requires alternative strategies. The ability of photoactivated collagen-embedded flavins (PCF) to reduce bioburden in infected pressure ulcers was investigated. DESIGN AND METHODS:
Two pressure ulcers were created on the dorsum of female BALB/C mice (n=40, 35 g) maintaining a 5 mm skin bridge between lesions. Ulcers and surrounding skin were covered with Tegaderm™ and inoculated with 0.1 mL of 1 × 10(5) colony-forming units (CFU)/mL methicillin-resistant Staphylococcus aureus (MRSA). Fluid was permitted to reabsorb for 10 min. In experiment 1, one wound from each animal was treated using PCF and photoradiation (PCF+R, n=12) or photoradiation alone (R, n=11). Composite dressing-treated wounds received 1 × 1 cm PCF discs. Overlying Tegaderm was excised, and PCF was placed over the wound and again covered with Tegaderm. Wounds were irradiated at 455 ± 5 nm (350 mW, 1 cm spot diameter, 15 min) using a diode laser 10 min after placement. Controls received no PCF or photoradiation (C, n=12). Animals were euthanized 24 h post-therapy. Quantitative bacterial counts (CFU/g tissue) were determined. In experiment 2, composite dressing-treated wounds were irradiated at 455 ± 5 nm (350 mW, 1 cm spot diameter, 15 min) using a diode laser 10 min after daily PCF placement (0, 1, 2, or 3 treatments, n=8/group). Controls received no treatment. Wounds were cultured daily. Animals were euthanized on day 7 post-infection. Quantitative bacterial counts were determined.RESULTS:
PCF+R significantly reduced bacterial counts at 24 h (experiment 1, p<0.0001; experiment 2, p<0.05). The bacterial counts in rats receiving photoradiation alone were no different from those of untreated controls (experiment 1, p=0.24). PCF+R produced a 2-3 log reduction in bacterial counts (experiment 2, p<0.001). Antibacterial effects increased with number of treatments, and persisted for several days post-therapy (p<0.002).CONCLUSIONS:
PCF+R inhibited bacterial growth in this model. This effect increased with successive treatments, persisting several days post-therapy. Further studies to optimize this treatment modality are warranted.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fotoquimioterapia
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Infecções Estafilocócicas
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Colágeno
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Úlcera por Pressão
/
Flavinas
Limite:
Animals
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article