Hemocompatibility of stent materials: alterations in electrical parameters of erythrocyte membranes

BACKGROUND: It is presently unknown if stents used in the correction of artery stenosis are fully hemocompatible or if their implantation causes alterations at the level of the plasma membrane in red blood cells. METHODS: We addressed this important issue by measuring the passive electrical properties of the erythrocyte membrane before and after stent insertion by means of dielectric relaxation spectroscopy in the radiowave frequency range in a series of patients who were undergoing standard surgical treatment of arterial disease. RESULTS: Our findings provide evidence that full hemocompatibility of stents has not yet been reached, and that there are some measurable alterations in the passive electrical behavior of the red blood cell membrane induced by the presence of the stent. CONCLUSION: It is possible that these changes do not have any physiological significance and simply reflect the intrinsic variability of biological samples. However, caution is urged, and the technique we describe here should be considered when investigating the hemocompatibility of a medical device at a cell membrane level.