Microfluidic device for axonal elongation control

This paper presents a novel microfluidic device for controlling axonal elongation dynamically by releasing nerve growth factor (NGF) onto a nerve cell. The presented device consists of nano-holes for NGF release and a micro valve for its release control. The amount of NGF that stimulate cells can be controlled very precisely by opening and closing the microvalve. Experiments using a fluorescent solution showed that constant chemical release through the nano-holes was successfully controlled by opening and closing the microvalve at about 2 Hz. This result indicates that the switching control of the microvalve will generate desired concentration of chemicals released from the nano-holes. Moreover, axonal guidance was tested on the fabricated device. We succeeded in guiding an axon of the cell in the direction of the nano-hole array along the NGF concentration gradient.