A NEW BLOOD COMPATIBLE AND PERMSELECTIVE HOLLOW-FIBER MEMBRANE FOR HEMODIALYSIS

The authors have prepared a blood compatible and highly permselective hemodialysis membrane composed of polyether segmented nylon. This bloc k copolymer was synthesized by polycondensation of bis-3-aminopropyl-p oly(tetramethylene oxide) (PTMO) and (imino-1,3-bismethyl-cyclohexyl-i minoisophtharoyl) (NyBI) prepolymer obtained by polycondensation of 1, 3-bis(aminomethyl)cyclohexane (B) and isophthalic acid (I). The molecu lar weight (MW) calculated from the number of end-groups was 16,000-21 ,000. In vitro blood compatibility was evaluated in terms of platelet adhesion onto the surface. PTMO-NyBI surfaces showed excellent platele t adhesion preventing properties. The PTMO-NyBI hollow fiber membrane was obtained by a dry-wet spinning process. The membranes had higher p ermeability coefficients for macromolecules ranging from MW 10,000 to 20,000 than polysulfone hollow fiber membrane (PS membrane), and had a cceptably low albumin permeability for use as a dialysis membrane. The ex vivo blood compatibilities of PTMO-NyBI membrane and PS membrane w ere investigated by extracorporeal circulation in a pig model. The PTM O-NyBI membrane gave excellent results when assessing hemodialysis leu kopenia, oxidative burst, and free platelet count decrease.