Advanced Thromboresistant/Antimicrobial Nitric Oxide Releasing Materials/Devices/Sensors: Development and Biomedical Applications

Nitric oxide (NO) has many physiologically important properties, including serving as a potent antithrombotic, antimicrobial, anti-inflammatory, and vasodilation agent. These properties make NO release/generation potentially useful for developing improved medical devices. In this presentation, recent efforts to develop both chemical and novel electrochemical/photochemical approaches for controlled release/generation of NO for use in the development of various biomedical devices/systems will be described. Early work with diazeniumdiolate type NO donors incorporated within polymeric coatings on the surface of implantable chemical sensors demonstrated how the NO release can greatly improve the accuracy in sensing oxygen/carbon dioxide/glucose, etc. continuously within the bloodstream by preventing platelet adhesion/clot formation on the surface of the implanted sensors. A more recent and promising chemical-based NO release method involves the use of S-nitroso-N-acetylpenicillamine (SNAP) as an NO donor impregnated within various plastic medical tubing/films. Devices and chemical sensors prepared with SNAP-doped polymers exhibit long-term NO release (up to 1 month), reduced clotting in vivo, and significantly less microbial biofilm formation on their surfaces when tested in vivo. An electrochemical approach to create NO for medical use is based on the electro-reduction of inorganic nitrite anions to NO using Cu(II)-ligand complexes as mediators. This new electrochemical NO delivery method can be adapted to develop a gas phase NO generator system that can replace the costly tanks of NO used currently for inhaled NO therapy in hospitals. In addition, novel photochemical gas phase NO generators have been developed using films made with S-nitrosothiols within and LED light sources, with the intensity of light controlling the output gas phase NO levels achieved for inhalation therapy. Charles N. Reilley and Royce W. Murray Award - SEAC