P16 – Antibacterial effect of a nitric oxide releasing sachet

Author(s):
Michael Neidrauer, Aparna Bhattacharyya, Sarah Julius, Carli Moorehead, Jonell Belle, Kenneth Barbee, Suresh Joshi, Zeomedix, Inc.

Background: Nitric oxide is a broad spectrum antimicrobial agent that has the potential to reduce surgical infections when delivered at controlled rates.

Hypothesis: The rate of nitric oxide released from sachets containing nitric oxide loaded zeolite powder can be controlled by altering the formulation of the sachet, and antibacterial amounts of nitric oxide can be released from some sachet formulations.

Methods: Single-use sachets containing nitric oxide loaded zinc-exchanged zeolite A in an emulsifying ointment base were developed using polyurethane and ethylene vinyl acetate (EVA) films. The rate at which nitric oxide is released from the sachets upon contact with water was characterized using a chemiluminescence detection system. The antimicrobial efficacy of the sachets was tested in vitro by inoculating agar slurry with methicillin-resistant Staphylococcus aureus (MRSA) to a final concentration of 10^8 c.f.u. / ml. Inoculated agar was placed on moistened nitric oxide sachets and control sachets (containing zeolite ointment without nitric oxide). The sachets were incubated for 24 hours, the agar was removed, and a colony count assay was performed. Log-reductions were calculated by comparing nitric oxide sachets to control sachets.

Results: Nitric oxide was released from the sachets at rates ranging from 0.250 to 1.50 micromole per square cm of surface area. Log reductions of MRSA ranged from 0 to 6, and increased as the rate of nitric oxide release from each sachet increased.

Conclusions: This work demonstrates that antibacterial amounts of nitric oxide can be released from single-use sachets that could potentially be applied to infected skin or wounds.