Impact of surface electric properties of carbon-based thin films on platelets activation for nano-medical and nano-sensing applications

Varvara Karagkiozaki^1,2, Stergios Logothetidis¹, Sylvie Lousinian1, George Giannoglou²

¹Physics Department, Laboratory for Thin Films – Nanosystems and Nanometrology (LTFN); ²Medical School, AHEPA University General Hospital, 1st Cardiology Department, Aristotle University of Thessaloniki, Greece

Abstract: Electric surface properties of biomaterials, playing key role to various biointerfacial interactions, were related to hemocompatibility and biosensing phenomena. In this study, the examination of surface electric properties of amorphous hydrogenated carbon thin films (a-C:H) was carried out by means of electrostatic force microscope (EFM) and observation of differences in spatial charge distribution on the surface of the examined films during platelets adhesion was made. The thrombogenic potential of a-C:H thin films developed by  agnetron sputtering with ∼42% sp³ content and hydrogen partial pressure during deposition was evaluated, by in situ observation with atomic force microscope (AFM) of platelets’ activation and their subsequent adhesion. Platelet-rich plasma drawn from healthy donors was used and semi-contact mode of AFM was applied. Platelets behavior and their correlation with the electric surface properties of the examined a-C:H films by EFM was made for hemocompatibility enhancement and sensing platelets that are less electrical negatively charged and with higher tendency to aggregate and form thrombus. The results are discussed in view of the effect of different deposition conditions of hydrogenated carbon films on their structural and morphological characteristics, surface roughness and electrical properties attributing to different hemocompatibility and sensing aspects.

Keywords: amorphous hydrogenated carbon, platelets, thrombogenicity, atomic force microscopy, electric force microscopy, medical applications