Negative pressure wound therapy (NPWT) is a prevalent treatment for traumatic, battlefield-related injuries. Wound contamination often occurs since greater than 75% of military wounds test positive for a pathogenic isolate at the time of injury. GRANUFOAM Silver by KCI is the most commonly used variation of commercially available antimicrobial foam for NPWT. However, silver nanoparticles are minimally effective against biofilm. This project incorporates a biofilm-specific bactericide into a PU foam matrix that is capable of reducing biofilm-bioburden in an in vivo porcine excision wound model. A PU foam was developed and infused with a 10% w/w concentration of CZ-01179 to compare against GRANUFOAM Silver which also has a 10% w/w concentration of silver nanoparticles.. An in vivo porcine full-thickness excision wound model was developed using Yorkshire pigs, 35-45 kg. The pigs were anesthetized and subjected to a surgical procedure creating four wounds, two with dimensions of 4x4 cm and two with dimensions of 3x3 cm, down to the fascia of the epaxial muscles. Upon completion of NPWT treatment, the pig was sacrificed and the wounds were harvested for microbiological quantification and histological analysis. The CFU/g of the tissue was attained through homogenization of the tissue followed by serial dilution. Histological analysis proceeded to understand the geography of biofilm in the tissue.
Inoculation of the full-thickness excision wounds resulted in ~8 log10 MRSA, A. baumannii, and natural flora CFU/g of tissue. After 7 days of treatment, V.A.C. GRANUFOAM DressingTM produced a +.3 log10 against MRSA, 1 log10 against A. baumannii, and 1 log10 against natural flora. Treatment with GRANUFOAM Silver produced a .1 log10 reduction against MRSA, 1 log10 against A. baumannii, and 1.7 log10 against natural flora. Treatment with CZ-01179 PU foam resulted in a 3.1 Log10 reduction against MRSA, 3.8 Log10 reduction against A. baummanii, and 3.7 Log10 reduction against natural flora.