Interaction of artificial carbon pyroceram mitral valve with blood plasma

Abstract

The nanocrystal material of artificial heart valve obtained under sintering of 15 mass.% B₄C with the crystal size <10 nm, uniformly spread out in 85 mass.% carbon with the particle size ~10 nm, has exceptionally high chemical stability in the blood plasma. In this paper the electrochemical interaction resulting from a contact with a possible microad-ditive.for example iron, on the valve surface is experimentally modeled by polarization from external current source, specially to create the extreme corrosion situation. The interaction kinetics study was carried out at 37^oC using the method of anodic polarization curves. For the spectral-photometric determination of boron tracks in a solution the citrcumin was used as an analytical reagent, for iron tracks definition in the spume-like film formed after polarization - the method of emissive spectroscopy. It was established that in the case of microgal-vanic elements rise at the potential of 0.4 V, the formation of chemisorped oxygen film began while at -1.0 V the stable passivation of valve surface took place as a result of low electro-conductive nanostructured carbon film formation. It was shown that this film was formed at the discharge on the valve surface of corresponding blood α-amino acids (amino acid remains of complicated chains of its proteins) containing in their structure the heterocycle rings. Using the method of sessile drop, a momentaiy wetting of valve by blood plasma was established (the wetting angle was equal to 50 ^o) that also promoted the formation on its surface the stable protective film.