Cellular patterning plays an essential role in the development of cell-based biosensors, cell culture analogues and tissue engineering. In particular addressability at cell level is needed for the recording of neuronal activity and interpretation of neuronal communication, thus providing insight in learning and memory processes as well as in the influence of drugs on neuronal activity.
In this paper, we report an approach to guide neuronal growth into simplified networks with single cell resolution. This enables direct correlation of individual neurons with relevant positions on a chip surface and can improve activity recordings by means of microelectrodes1 or field-effect transistors. Our method is based on aligned micro contact printing and allows the deposition of different types of guidance cues with micrometer precision in an easy manner. Making use of a flipchip bonder, we have created patterns of poly-L-lysine (PLL) and laminin to guide the development of neuronal networks. To ensure long-term stability of a neuronal pattern, chemical guidance cues alone do not suffice. Cell compliance to the cytophilic pattern seldomly extends beyond the duration of one week in culture. We have therefore made use of the hydrophobic properties of fluoropolymers such as teflon to discourage neuronal adhesion and at the same time create topography to hold the neurons mechanically in place. This cytophobic pattern was complemented with an aligned deposition of PLL between the teflon lanes. In this paper, aligned micro contact printing, combined chemical and topographical functionalisation of surfaces and the results of the evaluation in primary hippocampal cultures by immunocytochemical staining will be discussed.
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