Fluorescence microspectroscopy as a tool to study mechanism of nanoparticles delivery into living cancer cells.

Lack of better understanding of nanoparticles targeted delivery into cancer cells calls for advanced optical microscopy methodologies. Here we present a development of fluorescence microspectroscopy (spectral imaging) based on a white light spinning disk confocal microscope with emission wavelength selection by a liquid crystal tunable filter. Spectral contrasting of images was used to localize polymer nanoparticles and cell membranes labeled with fluorophores that have substantially overlapping spectra. In addition, fluorescence microspectroscopy enabled spatially-resolved detection of small but significant effects of local molecular environment on the properties of environment-sensitive fluorescent probe. The observed spectral shift suggests that the delivery of suitably composed cancerostatic alkylphospholipid nanoparticles into living cancer cells might rely on the fusion with plasma cell membrane.