SURFACE AND BLOOD-CONTACTING PROPERTIES OF ALKYLSILOXANE MONOLAYERS SUPPORTED ON SILICONE-RUBBER

Self-assembled monolayers of alkylsiloxanes supported on polydimethyl siloxane (PDMS) rubber were used as model systems to study the relatio n between blood compatibility and surface chemistry. The inner lumen o f PDMS tubes was first treated with an oxygen plasma. The resultant ox idized surfaces were postderivatized by reacting them with alkyltrichl orosilanes to form the monolayer films. The chemical properties of the monolayers were controlled by varying the head-group chemical composi tions. Surface derivatization was verified using variable-angle X-ray photoelectron spectroscopy (XPS or ESCA). Blood compatibility was eval uated using a canine ex vivo arteriovenous series shunt model. Surface s grafted with hydrophobic head-groups as -CH3 and -CF3 had significan tly lower platelet and fibrinogen deposition than the surfaces compose d of hydrophilic groups such as -CO2CH3, -(CH2CH2O)(3)COCH3, and -(OCH 2CH2)(3)OH. (C) 1995 John Wiley & Sons, Inc.