Zixuan Lu1,Chiara Barberio1,Aimee Withers1,Anna-Maria Pappa1,2,Alexandra Wheeler1,Konstantinos Kallitsis1,Eleonora Martinelli1,Achilleas Savva1,Walther Traberg-Christensen1,Róisín Owens1
University of Cambridge1,Khalifa University of Science and Technology2
Zixuan Lu1,Chiara Barberio1,Aimee Withers1,Anna-Maria Pappa1,2,Alexandra Wheeler1,Konstantinos Kallitsis1,Eleonora Martinelli1,Achilleas Savva1,Walther Traberg-Christensen1,Róisín Owens1
University of Cambridge1,Khalifa University of Science and Technology2
Neuronal ion-channel proteins are crucial membrane components directly related to neuron electrical activities. Disturbance of neuron signals and natural toxin effects caused by Ion-channel dysfunctional diseases still burden the global healthcare system. The study of native ion channels from cell membranes provides a simplified and direct model to study the drug and toxin effects on targeted ion-channels.<sup>1</sup> Microelectrode arrays were fabricated and coated with conducting polymer poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) as the active interfacing layer.<sup>2</sup> SH-SY5Y neuroblastoma cells was chemically differentiated with a 10-day process, and significant increase of neuronal marker expression was detected by immunofluorescence imaging and Western blot. Differentiated cells show a drastic increase of neurite outgrowth, which is an important benchmark of mature neurons. Further, native-neuronal membrane vesicles (also called blebs) were chemically induced from SH-SY5Y. By vesicle-fusion process, the SH-SY5Y membranes were successfully integrated onto the organic microelectrode arrays (OMEAs) and characterized by electrical (electrochemical impedance spectroscopy (EIS)) and optical (fluorescent recovery after photobleaching (FRAP)) methods. Then, calcium-ion channel blocking-effects with an antiarrhythmic drug, verapamil, were detected and analyzed by EIS. The calcium ion-channel protein was more than 50% upregulated after differentiation, and this difference was proved by a dose-response of the ion-channel blocking assay via electrical monitoring. Our neuronal membrane-on-chip system provides a time-efficient, cell-free, and label-free platform for pharmacology study and drug discovery on native ion-channel activities.<br/><b>References</b><br/> [1] Pappa, A.-M. et al. Optical and Electronic Ion Channel Monitoring from Native Human Membranes. ACS Nano acsnano.0c01330 (2020). doi:10.1021/acsnano.0c01330<br/>[2] Sessolo, M. et al. Easy-to-fabricate conducting polymer microelectrode arrays. Adv. Mater. 25, 2135–2139 (2013).