Physical properties and haemocompatibility of passive-carbon layer

Purpose: In the paper physical (surface topography, electrical properties) and antithrombogenic properties of the passive-carbon layer used for enhancing the surface properties of vascular stents made of Cr-Ni-Mo steel have been investigated. Design/methodology/approach: To characterize the electrical properties of carbon layer the silicon plate was used. The resistivity ρ and relative permittivity of the layer er have been determined on the basis of currentvoltage and capacitance-voltage characteristics. In vitro tests of biotolerance evaluation of the passive-carbon layer in blood environment have been carried out in the haemolysis tests (in the direct contact and from the extract) and in the blood clotting tests. Findings: The results of investigations have shown that deposition process of the passive-carbon layer of dielectric properties on the surface of implants made of Cr-Ni-Mo steel and used in interventional cardiology is an effective way of limiting the reactivity of their surface in blood environment and the blood clotting process in consequence. Research limitations/implications: Usefulness of the passive-carbon layer for interventional cardiology applications should be verified in in vivo tests. Originality/value: Modification of physical properties of surface of the metallic biomaterials applied in cardiovascular system by deposition of the passive-carbon layer which has dielectric properties limits the blood clotting process.