This article reports on the rapid, controllable immobilization of suspended mammalian cells within microfabricated environments, using a combination of electronic (dielectrophoresis, [DEP]) and chemical (polyelectrolyte multilayers, [PEMS]) forces.
DEP trapping combined with PEMS surface modification provides a useful and reliable strategy for manipulating cellular position and adhesion. When combined with PEMS surface treatment, cell immobilization initiated by DEP is retained through substrate interactions, enabling removal of DEP forces and changes to solution composition without dislodging immobilized cells. Microfluidic delivery of chemicals to the trapping region facilitates nutrient delivery or cell monitoring and characterization, continuously or after delivery of soluble stimuli. Since dielectrophoresis can discriminate between cell types, it may be possible to systematically pattern discrete cell populations to create intricate co-cultures. In demonstrating for mammalian neural cells and pluripotent cells able to differentiate along, among others, neuronal pathways, this approach can be applied to assays within microenvironments for a variety of cell types. 1 figure and 30 references