Gaseous Nitric Oxide Under Pressure for the Treatment of Infected Wounds: A Mammalian Model

Wound infections, including chronic and acute, affect millions of people throughout the world and can be a contributing factor to amputations and even death. Traditional methods of treatment are becoming increasingly less effective due to both resistance and the formation of biofilms.

A novel treatment using gaseous nitric oxide (gNO) has shown promising results to help inhibit or eradicate these infections. This study using 2% gNO delivered to mammalian (porcine) wounds infected with either Staphylococcuss aureus or Pseudomonas aeruginosa at varying times with additional pressure added to determine the potency of gNO in reducing bacterial load. A wound was created to a size 2.0 cm, infected with 1x108 cfu/mL, and left to incubate for one hour. A manifold and custom exposure devices were used to ensure delivery of the gas to the infected wound site.

Flow rate was set at 100c while additional pressure was adjusted to 3.7 PSI (0.25 ATM) and 4.4 PSI (0.299 ATM) for an exposure time of 40 and 50 minutes. Post exposure, tissues were homogenized and serial dilutions were streaked on agar plates and incubated, then colony forming units were counted. Results indicate a 102–103 cfu/gm reduction for Staphylococcuss aureus, while Pseudomonas aeruginosa showed a 104 cfu/gm reduction. Additionally, histology was evaluated to determine the toxicity of biopsy samples.

Based on the results, gNO has extreme potential to help reduce bioburden in infected wounds in a much shorter time than traditional methods used today.