Probing molecular crowding in compressed tissues with Brillouin light scattering

Abstract

Significance Volume regulation is key in maintaining important tissue functions, such as growth or healing. In this process, the role of efflux of cellular fluids is difficult to capture due to the lack of apt technologies. Here, we use a tool based on Brillouin light scattering (BLS) that uses the interaction of a laser light with inherent picosecond timescale density fluctuations in the sample. We induced gradual volume decrease in multicellular spheroids using osmotic perturbations. BLS revealed a nonlinear increase of the tissue compressibility due to the subsequent increased biopolymer crowding within the cells. Our findings should inspire research regarding volume regulation and cellular crowding in tissues and stimulate the emergence of models for cell mechanics at short timescales.