Cellular Immobilization Within Microfluidic microenvironments: Dielectrophoresis With Polyelectrolyte Multilayers
Samuel P. Forry, D. R. Reyes, Michael Gaitan, Laurie E. Locascio
The development of biomimetic microenvironments will improve cell culture techniques by enabling in vitro cell cultures which mimic in vivo behavior1-3; however, experimental control over attachment, cellular position, or inter-cellular distances within such microenvironments remains challenging. We report here the utilization of dielectrophoresis (DEP) for rapid and controllable immobilization of suspended mammalian neurons within microfabricated microenvironments. Layer-by-layer surface modification with polyelectrolyte multilayers (PEMs) amenable to cellular attachment caused temporary DEP immobilization to persist after DEP forces were removed. Delivery of various chemicals through the microenvironment facilitated cell monitoring and characterization in response to chemical stimuli. Laminar flow through the microenvironment was used to confine solution flow, enabling specific delivery of chemicals to select immobilized cells while the remaining cells provided a in situ experimental control. Demonstrated here for mammalian neural cells, DEP immobilization and surface modification could facilitate small cell cultures within microenvironments for a variety of cell types. The ability to culture and study cells outside of their natural environment is a powerful tool for understanding cell behavior, investigating cellular response to stimuli, evaluating drug efficacy and toxicity ex vivo, and facilitating drug discovery. However, the equipment utilized in traditional cell culture methods (Petri dishes and tissue culture flasks) is quite dissimilar from the in vivo environment, and cells in culture can behave quite differently from their in vivo counterparts4-7. Continued: See attached.