An investigation of the in vivo stability of poly(ether urethaneurea) blood sacs

In this paper we investigate the biostability of a series of Biolon(R) bloo d sacs that were utilized in electric total artificial hearts for time peri ods of up to 19 weeks. A battery of experimental probes, including scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), were used to characterize the bulk and surface properties of explanted and cont rol blood sacs. Gel permeation chromatography (GPC) experiments showed that generally there was a dramatic increase in average molecular weight at lon ger implantation times. However, SEM and GPC observations suggest significa nt deterioration of the flex regions of right blood sacs after 17 weeks of sen ice. XPS experiments indicated appreciable silicon and hydrocarbon conc entrations on blood-contacting surfaces both before and after implantation, and we speculate as to their origin. (C) 1999 John Wiley & Sons, Inc.