Characterization of Au, Au/GO and Au/rGO surfaces for carotid endothelial cell proliferation by electrical impedance spectroscopy method

Abstract

Endothelium dysfunction may be the cause of cardiovascular diseases such as heart attack, aneurysm, or atherosclerosis. Thus understanding endothelial cell properties helps explaining the reasons and treatment of cardiovascular diseases. Electrical impedance spectroscopy (EIS) is a real-time tool for evaluation of cell behavior. In this dissertation, human carotid artery endothelial cell (HCtAEC) proliferation on graphene derivatives was analyzed through EIS, optical images, Alamar Blue cell viability test and cell staining. Gold (Au) layers were deposited on glass surfaces by using photo-lithographic technique and plasma enhanced chemical vapor deposition. Graphene oxide (GO) was immobilized on Au electrodes through self-assembly monolayers (Au/GO). Hydrazine vapor reduction process was performed in order to obtain reduced graphene oxide (rGO) surfaces (Au/rGO). Au, Au/GO and Au/rGO surfaces were examined through SEM images and water contact angle measurements. These coatings were performed on the electrodes used in EIS analysis. EIS analysis (100 Hz-1 MHz) was performed for HCtAECs cultured on the Au, Au/GO Au/rGO electrodes for 10 days. Results showed that GO and rGO coatings did not prevent neither the electrical measurements nor the cell proliferation. rGO had a positive effect on HCtAEC proliferation. The rate of increase of impedance change from Day 1 to Day 10 was nearly five-fold for all electrode surfaces. Alamar Blue assay performed to monitor cell proliferation rates between groups, and rGO has shown the highest Alamar Blue reduction value of 43:65 8:79%. Acridine orange/propidium iodide (AO/PI) staining showed that cell viability on electrodes was similar to tissue culture plate.|Keywords : Graphene Oxide, Reduced Graphene Oxide, Electrical Impedance Spectroscopy, Human Carotid Artery Endothelial Cell, Endothelialization.