  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.
