Usefulness of passive-carbon layer for implants applied in interventional cardiology

In the work the usefulness of passive-carbon layer deposited on surface of coronary stents made from Cr-Ni-Mo steel has been investigated. Particularly, investigations of pitting corrosion resistance in conditions which are taking into consideration the technique of stents implantation have been carried out. Usefulness of the layer has also been evaluated in conditions of changing of cyclic loading. A special stand for fatigue tests of the stents was made for better simulation of heart's work. Fatigue tests were carried out by 3 months in Tyrode's physiologic solution with frequency of 180 cycles per minute. Moreover, the topography of carbon layer with the use of atomic force microscopy method has been investigated. The obtained results have pointed out on the usefulness of passive-carbon layer for quality improvement of coronary stents surface.