Abstracts

LIGHT STIMULATION OF MAMMALIAN CELLS ON ORGANIC PHOTOCAPACITORS

Tony Schmidt1, Marie Jakešová2, Vedran Đerek3, Karin Kornmueller2, Oleksandra Tiapko1, Helmut Bischof1, Sandra Burgstaller1, Linda Waldherr1, Marta Nowakowska4, Christian Baumgartner5, Muammer Üçal4, Gerd Leitinger1, Susanne Scheruebel2, Silke Patz4, Roland Malli1, Eric Daniel Głowacki2, Theresa Rienmüller5, Rainer Schindl1

1Gottfried Schatz Research Center, Medical University of Graz, Graz, 8010 Austria; 2Central European Institute of Technology, Brno University of Technology, Purkyňova 123, 61200 Brno, Czech Republic; 3Department of Physics, Faculty of Science, University of Zagreb, Bijenička c. 32, 10000, Zagreb, Croatia; 4Department of Neurosurgery, Medical University of Graz, Graz, 8010 Austria; 5Institute of Health Care Engineering with European Testing Center of Medical Devices, Graz University of Technology, Austria

Optoelectronic stimulation is a minimal invasive method that combines light and electronics to generate electrical signals in attached cells by depolarizing the membrane potential. In this approach, we use nontoxic organic pigments that form a planar semiconductor on top of ITO. Light stimulation and signal propagation require close contacts between cell membranes and pigments. Here, we performed single cell electrophysiological recordings on mammalian cells transfected with the outward rectifying voltage-gated potassium channel Kv1.3. Attached to our optoelectronics, the channels activation threshold shifts upon light illumination (660 nm). In a further step we used primary neurons and cultivated them on our devices for several weeks. We could biochemically prove cell viability and show with SEM that neuronal networks easily establish and exhibit neurite outgrowth on the devices. Importantly, we could proof that the light-induced cell membrane depolarization and the described shift in opening of the voltage-gated ion channels is sufficient to trigger action potentials in neurons. These electrophysiological characterizations describe a significant step towards the in-vivo stimulation for vision restoration and regeneration of axonal sprouting in damaged neuronal tissues.

Presenting author e-mail address: tony.schmidt@medunigraz.at