Therapeutic noninvasive drug delivery methods are desired as a means of simplifying medical procedures. This dissertation focuses mainly on utilizing light as the trigger for photochemical delivery of nitric oxide, a bioactive gaseous molecule. Relatively non-toxic delivery systems triggered by near infrared light are explored. The ideal wavelengths of light that penetrate biological organisms must take into account the various tissue components such as water, fat, and muscle content. The wavelength range best capable of not being absorbed by the previously mentioned tissues is situated in the near infrared from 650 to 1350 nm. It is noted that particular tissues have different extinction coefficients at various wavelengths. Light is an ideal trigger for photochemical release of a drug due to its ability to be pulsed, focused, or mixed with other wavelengths, allowing temporal, spatial, dosage control.

The nitric oxide delivery systems explored in this dissertation were based on sequential multi-photon absorption of 980 nm light by lanthanide ions within crystal nanoparticles, which then upconvert the light into shorter wavelengths utilized to trigger the photochemical release of nitric oxide. The first delivery system consisted of meso-porous silica coated upconverting nanoparticles loaded with the nitric oxide precursor Roussin's Black Salt anion Fe4S3(NO)7-. The nanoparticles were dispersed in aqueous media and irradiated with 980 nm light and the nitric oxide released was determined by a Sievers based detection system. Such a system holds future promise due to its ability to be injected. The second method explored is a polydimethylsiloxane (PDMS) film loaded with upconverting nanoparticles and infused with Roussin's Black Salt. This latter system was also irradiated with 980 nm light in a helium environment and the nitric oxide released was determined.

The polydimethylsiloxane film method was explored further by placing them behind approximately 2.5 mm porcine tissue samples of muscle, fat or skin, then irradiated with 980 nm diode laser light. Interestingly, sufficient nitric oxide was released demonstrating the viability of material systems to encapsulate photochemical biological precursors.