In this talk, I
introduce and describe a particle-based biological model, incorporating ideas
from dissipative particle dynamics, elastic mechanics and force-based
heuristics, to explain the persistent rotation between adherent cell-cell pairs
cultured on micropatterned substrates. This biological observation is
particularly interesting, because the rotation of such cell-cell pairs runs in
the opposite reference frame from what is predicted from classical theories of
single cell locomotion. The reason for this exceptional behavior has not been
addressed previously. In the present model, I show how particle dynamics can
apply known biophysical parameters, including actomyosin forcing, viscous
dissipation and cortical tension, to physically explain this curious rotational
behavior. Without any artificial cues, the model spontaneously and consistently
reproduces the same rotational reference frame as observed experimentally. This
result corroborates the hypothesis that both rotational and morphological
phenomena are, in fact, physically coupled by an intracellular torque of a
common origin. Subsequent analyses then characterize the physical conditions
upon which such behavior can be expected. As a computational tool, this
particle based approach utilizes efficient and physically consistent concepts
to explain multicellular dynamics, and I advocate its use as a complement to
classical biological modeling tools, such as the Cellular Potts method.