Oriented and vectorial patterning of cardiac myocytes using a microfluidic dielectrophoresis chip - Towards engineered cardiac tissue with controlled macroscopic anisotropy

Recently, the ability to create engineered heart tissues with a preferential cell orientation has gained much interest. Here, we present a novel method to construct a cardiac myocyte tissue-like structure using a combination of dielectrophoresis and electro-orientation via a microfluidic chip. The device includes a top home-made silicone chamber containing microfluidic channels and bottom integrated microelectrodes which are patterned on a glass slide to generate dielectrophoresis force and orientation torque. Using the interdigitated-castellated microelectrodes, the induction of a mutually attractive dielectrophoretic force between cardiac myocytes can lead to cells moving close to each other and forming a tissue-like structure with orientation along the alternating current (ac) electric field between the microelectrode gaps. Both experiments and analysis indicate that a large orientation torque and force can be achieved by choosing an optimal frequency around 2 MHz and decreasing the conductivity of medium to a relatively low level. Finally, electromechanical experiments and biopolar impedance measurements were performed to demonstrate the structural and functional anisotropy of electro-oriented structure.