Patterning the topographical environment for mammalian cell culture using laminar flows in capillaries

This paper describes the use of patterned flows of multiple laminar streams of etching solutions in capillaries to create various topographical features with sizes of 10-200 μm in poly(dimethylsiloxane) (PDMS). A variety of topographical features were created by using channels with obstacles, by adjusting the flow rates of etchant, or by controlling the duration of etching. Bovine capillary endothelial cells aligned parallel to features when grown inside these topographically patterned capillaries with 10 μm ridges. The capillaries with topographical features could also be further patterned with surface-attached red blood cells and surface-adsorbed proteins, using laminar flows. This two-stage patterning produces patterns of proteins and cells on the topography with alignment between the different features and patterns. The technique allows simultaneous micropatterning of multiple cell culture environments using the same capillary system