  Biological cells in living tissues form dynamic patterns with local
orientational order and topological defects. Here we demonstrate an approach to
produce cell monolayer with the predesigned orientational patterns using human
dermal fibroblast cells (HDF) placed onto a photoaligned liquid crystal
elastomer (LCE). The alignment of cells is caused by anisotropic swelling of
the substrates in contact with the aqueous cell growth medium. The patterns
predesigned in the LCE cause a strong spatial variation of cell phenotype
(evidenced by shape variations), their surface density and number density
fluctuations. The concentration of cells is significantly higher near the cores
of positive-strength defects as compared to negative-strength defects.
Unbinding of defect pairs intrinsic to active matter is suppressed by
anisotropic surface anchoring. The geometry of arrays allows one to estimate
the elastic and surface anchoring characteristics of the tissues. The
demonstrated patterned LCE approach could be used to control the collective
behavior of cells in living tissues, cell differentiation, and tissue
morphogenesis.
