Nanoparticle analysis of cancer cells by light transmission spectroscopy

We have measured the optical properties of cancer and normal whole cells and lysates using light transmission spectroscopy (LTS). LTS provides both the optical extinction coefficient in the wavelength range from 220 to 1100 nm and (by spectral inversion using a Mie model) the particle distribution density in the size range from 1 to 3000 nm. Our current work involves whole cells and lysates of cultured human oral cells in liquid suspension. We found systematic differences in the optical extinction between cancer and normal whole cells and lysates, which translate to different particle size distributions (PSDs) for these materials. Specifically, we found that cancer cells have distinctly lower concentrations of nanoparticles with diameters less than 100 nm and have higher concentrations of particles with diameters from 100 to 1000 nm-results that hold for both whole cells and lysates. We also found a power-law dependence of particle density with diameter over several orders of magnitude.