Gel-impregnated pore membranes with mesh-size asymmetry for biohybrid artificial organs

Membranes based on mechanically supported poly(vinyl alcohol) (PVA) hydroge ls with mesh-size asymmetry were developed for potential application in bio hybrid artificial organs. The pores of cellulose ester microfiltration memb ranes were impregnated with a PVA solution, which was lightly crosslinked w ith glutaraldehyde and then modified under a glutaraldehyde gradient to pro duce mesh-size asymmetry. Permeation experiments were performed with the re sulting homogeneous and asymmetric gel-impregnated pore membranes (GIPMs). Creatinine (MW: 113), goat Fab (MW: 50 kD) and human IgG (MW: 150 kD) were used to simulate the molecular size of nutrients, therapeutic proteins, and immunological molecules, respectively. The transport properties of the GIP Ms were compared to those of conventional ultrafiltration (UF) and dialysis membranes. Experimental results indicate that GIPMs with mesh-size asymmet ry have thickness-normalized creatinine. permeabilities that are slightly h igher than those in cellulosic UF membranes but as much as 100% greater tha n those in polysulfone UF or cellulosic dialysis membranes. IgG permeabilit ies in the GIPMs are from 5 to 50 times lower than those in the UF membrane s. Fab permeabilities are 6 to 40 times higher in the UF membranes than tho se in the GIPMs, but the required permeability for a therapeutic protein is application specific. GIPMs may also be suitable as an alternative for hem odialysis. (C) 2000 Elsevier Science Ltd. All rights reserved.