Determination of living cell characteristics and behavior using biophotonic methods Dominik G. Rabus* a , Alexander Welle b , R. Adam Seger a , Yasuhisa Ichihashi c , Mathias Bruendel c , Jeremy Hieb a , Michael Isaacson a a Baskin School of Engineering, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064-1077, USA; b Institute for Biological Interfaces, Forschungszentrum Karlsruhe GmbH, P.O. Box 3640, 76021 Karlsruhe, Germany; c Institute for Microstructure Technology, Forschungszentrum Karlsruhe GmbH, P.O. Box 3640, 76021 Karlsruhe, Germany ABSTRACT This paper describes the development of methods for the determination of the characteristics and the behavior of living neural cells. A technology which is used is the deep ultraviolet (DUV) modification of methylmethacrylate polymers which leads to a new surface chemistry affecting the selective absorption of proteins and the adhesion of living cells in vitro. The bi-functionality of the modified polymer chips supporting waveguides and cell anchorage capabilities at the same time provides the opportunity to monitor protein adsorption, cell attachment and spreading processes by evanescent-field techniques. This allows the defined spatial control of a cell / surface interaction and leads to a combination of desired biological and optical properties of the polymer. Among them are the high sensitivity of cultured mammalian cells to, for example, environmental changes and special features of integrated optical waveguides like their online compatibility, minuteness and robustness. The scientific fields, biology and optics, meet at the polymer surface becoming a cell culture substrate together with an optical waveguide by the application of special patterning and fabrication technologies. In addition to the already mentioned fabrication and immobilization technology, the technique proposed also offers the possibility of being able to couple to microstamping processes and to also incorporate electrical measurements on individual cells. Thus, by extending this method and coupling it to the DUV technique described above the possibility is given of being able to simultaneously optically and electrically interrogate individual cellular processes with spatial resolution. Keywords: polymer, waveguide, DUV lithography, biophotonics, cells 1. INTRODUCTION Integrated micro- and nanosystems for the determination of the characteristics and the behavior of living cells have attracted a lot of attention lately. For decades technical limitations have forced biologists to record the behavior not of individual proteins in single or few cells, but of populations of proteins in thousands or even millions of cells. Given the complexion of the cellular mechanisms, the result was an average idealized description of cellular behavior. To understand these complex cellular mechanisms, it is necessary to determine how individual parts are integrated in space and time to form complex cellular functions and to measure multiple variables of living cells in real time. Integrated bio- photonic devices are amongst the most promising systems for fulfilling this task. The paper focuses on the development of a platform which is able to culture and pattern live single cells for a sufficient period of time, enables the integration of optical evanescent field polymer based photonic devices, and provides means to integrate electronic readout possibilities. This is realized by a combination of engineering nanofabrication and biological methods forming a cross discipline approach. *rabus@soe.ucsc.edu; phone 1 831 459-1043; fax 1 831 459-4829; www.soe.ucsc.edu Invited Paper Optofluidics, edited by Demetri Psaltis, Yeshaiahu Fainman, Proc. of SPIE Vol. 6329, 63290H, (2006) · 0277-786X/06/$15 · doi: 10.1117/12.681015 Proc. of SPIE Vol. 6329 63290H-1