Endothelial Cell Migration Regulated by Surface Topography of Poly(ε-caprolactone) Nanofibers

The
study of cell migration on biomaterials is of great significance
in tissue engineering and regenerative medicine. In recent years,
there has been increasing evidence that the physical properties of
the extracellular matrix (ECM), such as surface topography, affect
various cellular behaviors such as proliferation, adhesion, and migration.
However, the biological mechanism of surface topography influencing
cellular behavior is still unclear. In this study, we prepared polycaprolactone
(PCL) fibrous materials with different surface microstructures by
solvent casting, electrospinning, and self-induced crystallization.
The corresponding topographical structure obtained is a two-dimensional
(2D) flat surface, 2.5-dimensional (2.5D) fibers, and three-dimensional
(3D) fibers with a multilevel microstructure. We then investigated
the effects of the complex topographical structure on endothelial
cell migration. Our study demonstrates that cells can sense the changes
of micro- and nanomorphology on the surface of materials, adapt to
the physical environment through biochemical reactions, and regulate
actin polymerization and directional migration through Rac1 and Cdc42.
The cells on the nanofibers are elongated spindles, and the positive
feedback of cell adhesion and actin polymerization along the fiber
direction makes the plasma membrane continue to protrude, promoting
cell polarization and directional migration. This study might provide
new insights into the biomaterial design, especially those used for
artificial vascular grafts.