Acute cellular interaction with textured surfaces in blood contact

Textured blood-contacting surfaces can promote the formation of a blood-com patible pseudo-neointima. We hypothesized that by controlling the surface t exturing, the pseudo-neointima thickness could be controlled. The hypothesi s was tested experimentally by fabricating the polyurethane textured surfac es with three different fiber lengths, and exposing them simultaneously to the flowing blood in an ovine ex vivo carotid-jugular series shunt for peri ods up to 4 h. The textured surface consisted of regularly spaced tapered m icro-fibers of defined length on a smooth base-plane surface. Because of th e simple surface topography, detailed computational fluid-dynamic modeling of the surface could be obtained as a parallel study. Experimental results showed that white cell was the predominant cell type deposited on the textu red surfaces, whereas macroscopic thrombus formation occurred only in one o f nine blood-contacting experiments. White cell density on the textured bas e-plane surface was subsequently quantified by image-analyzing the electron micrographs of blood-contacted textured surfaces. The statistical analysis of cell densities on individual textured surfaces showed effects of wall s heer stress on the textured base plane (which was obtained from the fluid-d ynamic modeling), the longitudinal position of the test section in the seri es shunt, and blood-contact time. (C) 2000 John Wiley & Sons, Inc.