1999-05-31
16:15 at HG D1.1

Towards a Cell-Based Biochip : A Surface Approach

Solomzi Makohliso

Swiss Federal Institute of Technology, Lausanne

 The development of in vitro hybrid devices that involve interfacing biological tissue with microelectronics structures (bioelectronic devices), e.g. cell-based biosensors, is a growing trend. A key requirement in the development of this technology is the ability to spatially control and direct tissue deposition/cell adhesion with micron resolution. Towards a strategy for surface control and biopatterning of cell adhesion, Teflon AF®, an amorphous copolymer of polytetrafluoroethylene (PTFE), proved to be an excellent candidate for this purpose. Currently, we report results obtained with a process we established, using standard microelectronics procedures, for fabricating Teflon-AF into thin micropatterned films that could biopattern neural cell adhesion. Surface analytical tools like ESCA and ToF-SIMS proved invaluable in process design and optimization. Various neural cells were used to test the biopatterning efficacy of the fabricated films (1). Another widely cited parameter towards improving device performance of such cell-based biochips is the quality of the interface between the electrically active biological element and the electrode surface. We have been investigating the laminin-derived synthetic oligopetide, CDPGYIGSR, towards improving the neuron-electronics interface. This oligopeptide is known to promote adhesion of various cellular types. A biochip prototype was then realized, consisting of an array of gold microelectrodes grafted with the oligopeptides, and isolated with the Teflon-AF film. ToF-SIMS imaging was utilized to assess biochip surface chemistry (2). Neural cells were subsequently utilized to test the biopatterning efficacy of the biochip surfaces. (1). S.A. Makohliso, L. Giovangrandi, D. Leonard, H.J. Mathieu, M. Ilegems, P. Aebischer. Application of Tefloon-AF thin films for bio-patterning of neural cell adhesion. Biosensors   Bioelectronics 13(1998) 1227-1235. (2). S.A. Makohliso, D. Leonard, L. Giovangrandi, H.J. Mathieu, M. Ilegems, P. Aebischer. Surface Characterization of a Biochip Prototype for Cell-Based Biosensor Applications. Langmuir 15(1999) 2940-2946.