Numerical Model for the Deformation of Nucleated Cells by Optical Stretchers

TL;DR

This study models how nucleated cells deform under optical stretchers using advanced computational methods, revealing the significant impact of nucleus size on force distribution and cell deformation.

Contribution

It introduces a combined Dynamic Ray-Tracing and Immersed Boundary Method approach to simulate nucleated cell deformation under optical forces, accounting for shape-dependent stress distribution.

Findings

Nucleus size significantly affects force distribution on cell surface.

Optical forces cause notable deformation depending on nucleus size.

The model provides insights into cell deformation mechanisms under optical stretching.

Abstract

In this paper, we seek to model the deformation of nucleated cells by single diode-laser bar optical stretchers. We employ a recently developed computational model, the Dynamic Ray-Tracing method, to determine the stress distribution induced by the applied optical forces on a capsule encapsulating a nucleus of different optical properties. These forces are shape dependent and can deform real non-rigid objects; thus resulting in a dynamically changing optical stress distribution with cell and nucleus deformation. Chinese hamster ovary cell is a common biological cell that is of interest to the biomedical community because of their use in recombinant protein therapeutics and is an example of a nucleated cell. To this end, we model chinese hamster ovary cells as two three-dimensional elastic capsules of variable inner capsule size immersed in a fluid where the hydrodynamic forces are calculated using the Immersed Boundary Method. Our results show that the presence of a nucleus has a major effect on the force distribution on the cell surface and the net deformation. Scattering and gradient forces are reported for different nucleus sizes and the effect of nucleus size on the cell deformation is discussed.