Cell placement and neural guidance using a three-dimensional microfluidic array

Several fabrication techniques for making three-dimensional arrays of micro-wells for biological cell patterning and single-neuron guidance are presented. Methods for making complex 3d high-aspect-ratio structures in poly-dimethylsiloxane (PDMS) membrane are explored. In this work, three-dimensional micro-molds are made directly on silicon wafers though inductively coupled plasma reactive ion etching (ICP-RIE), and also using SU-8 negative photoresist. Cell placement is achieved through an array of 50-mum square holes in a 150-100 mum thick PDMS membrane, which is placed on a glass substrate. Vertical holes in the membrane are linked by horizontal tunnels on the glass side of the membrane, for use in neural guidance or delivery of drugs or nutrients. The effectiveness of the membrane for cell placement, growth and guidance was tested using fluorescent yeast cells and PC12 neuronal cells.