Long-wavelength, Photo-controllable Sources of Nitric Oxide Based on the Diazeniumdiolate Functional Group

Nitric Oxide, known to cause cell apoptosis, would be a useful agent to combat tumor cells in the body. Diazeniumdiolates, when dissolved in a solution at physiological condition, will release Nitric Oxide, NO. A photo-controllable group that absorbs in the visible red region is a good candidate for a protecting group to the molecule, due to red light being able to penetrate the skin much deeper than UV, with no damage to the tissues. A method of therapeutic application involves the attachment of the diazeniumdiolate complex with photo-controllable group to a dendrimer macromolecule. The dendrimer would automatically accumulate by the tumor cells due to the Enhanced Permeation and Retention, or EPR, phenomena, which is accumulation of macromolocules in tumor tissue due to little lymphatic drainage. Possible photo-controllable groups include benzophenoxazine analogues of the fluorescent dye, Nile Red. Synthesis and purification techniques are currently in progress on several of these analogues.