Abstract

Recently we demonstrated that the endogenous NAD(P)H compounds can be used to follow the bioenergetics of cells during treatment with nanodrug delivery systems [1]. For this purpose, we exposed live cancer cells with a novel nanodrug carriers and studied the fluorescence lifetime compounds of protein-bound and unbound NAD(P)H forms, which are spectrally indistinguishable, but vary in their fluorescence lifetimes. To excite the autofluorescence of the endogenous markers we used a standard femtosecond laser source (100fs, 730nm, 80 MHz, Tsunami, Spectra Physics), which allows a two photon excitation of the NAD(P)H compounds. The fluorescence lifetime signal was detected via a time-correlated single photon counting (TCSPC) detection scheme, and the appearance of a long fluorescence lifetime component indicates the changed metabolism of the cells at longer incubation time with the therapeutic agent.

© 2019 IEEE