Faculty Sponsor's Department:
Modern medicine presents an increasing need for site-specific drug delivery and release systems. Developing such a system can decrease collateral damage caused by currently used chemotherapy drugs as it would only deliver the drug to sites in need of treatment. Some systems involve structures which can encase and release a drug based on surrounding conditions, such as pH. Fluorescence-based imaging can allow us to track such drug release processes and observe their efficiency. One such imaging technique makes use of downconversion nanocrystals (DCNCs) which can be irradiated with near infrared (NIR) light and emit light of a longer wavelength through a Stokes process. NIR light, especially short wavelength infrared (SWIR) light around 1525nm, has good penetration in human tissue compared to visible light as it is not as readily absorbed and scattered by water and tissue. In this project we explored the use of polystyrene microspheres loaded with DCNCs and organic dye to track the ‘drug’ (organic dye) release process. The presence of organic dye and DCNCs together quenches the overall luminescence from the microsphere. When the ‘drug’ is released, the agents are no longer quenched and their emission signals can be distinguished, allowing us to see both the positions of the microspheres and the released drug. We observed the effects of organic dye concentration in DCNC-loaded polystyrene microspheres to find the optimal organic dye concentration for complete quenching. Advances in this research may lead to applications in pharmacokinetics involving noninvasive oral administration of cancer therapy drugs.