Hyperspectral two-photon near-infrared cancer imaging in vitro and in vivo

We present a novel way of optical detection of malignant cancer cell colonies by using multi-wavelength two-photon excited fluorescence from an environmentally sensitive Styryl-9M dye. We show that the two-photon excited fluorescence from colonies embedded in a tissue phantom depends on the type of cells as well as on the composition of the phantoms. We use the ratio between the fluorescence intensities excited at 1100 and 1200 nm to distinguish between samples containing no cell colonies, samples with colonies of normal cells and samples with cancer cells. The proposed method is a promising tool for non-invasive deep tissue photodetection diagnostics and for precise localization of malignant cells.