P-141 - Fluorescent nanodiamonds: potential free radical detectors in live cells

Abstract

High reactivity of free radicals makes them hard to detect in live cells. Modern methods for free radical detection often lack sensitivity, discrimination ability, and/or fail to provide intracellular context for their output. Fluorescent nanodiamonds (FND) can act as probes for magnetic properties of their environment. They are non-toxic and can be targeted to specific locations inside the cell. Free radicals are a major source of magnetic signal in cells, thus they can potentially be detected with FNDs. In this study, we focused on retrieving the context for the recorded signal from the mode of motion of individual FNDs. FND uptake in mammalian cells was confirmed with confocal microscopy. We used custom tracking software to record trajectories of individual particles for further analysis. FND speeds and diffusion coefficients allow one to easily distinguish between the FNDs located outside the cell, attached to the cell surface, moving in the cytoplasm, or restricted to a particular cellular compartment. These results provide the first step for automated registration of the FND environment, as it travels into the cell and in the cytoplasm. This approach might be useful for obtaining spatiotemporal context for free radical formation with high resolution and minimal interference