Gas transfer and blood compatibility of asymmetric polyimide hollow fiber

We have fabricated an asymmetric polyimide hollow fiber for use as a membra ne oxygenator. A dry/wet phase inversion process has been applied to a spin ning process to prepare the hollow fiber. The fiber structure consisted of a complete defect-free skin laver and a porous substructure characterized b y the presence of an open-cell structure and macrovoids. The outer diameter was 480 mum with a wall thickness of 50 mum. Transfer rates Of O-2 and CO2 in the asymmetric polyimide fiber were 2.3 x 10(-5) and 1.1 x 10(-4) (cm(3 )(STP)/(cm(2) s cmHg)), respectively. which were four times higher than tho se measured in the polydimethylsiloxane (PDMS) fiber of the presently-avail able membrane oxygenator. The (Q(O2) / Q(N2)) selectivity of the polyimide fiber was 4.9, indicating that the surface skin layer is essentially defect -free. The blood compatibility of the polyimide hollow fiber has been evalu ated in vitro and in vivo. The polyimide had an excellent blood compatibili ty when compared with PDMS,