Radiosynthesis of hydrogel confined to hollow-fiber membranes for the design of a bioartificial extracorporeal liver

HIDALGO R; VIZIOLI NM; SMOLKO E; ARGIBAY P; GRASSELLI M

RADIATION PHYSICS AND CHEMISTRY (OXFORD)

ELSEVIER

Año: 2007 vol. 76 p. 1419 - 1424

0969-806X

Current bioartificial extra-corporeal systems are bioreactors where cells are separated from the surrounding media by porous polymeric membranes. Such porous structure controls the exchange of substances -mainly according to their molecular size- by mass transfer processes such as convection, diffusion and osmosis. The present work focuses on the design of membranes that allow the differential diffusion of plasma metabolites and proteins such as immunoglobulin (IgG). This design will improve catabolites removal and also reduce possible immune response and virus infection. In this paper we demonstrate the feasibility to synthesize the hydrogels confined to the macroporous structure of membranes by radiation-induced in situ polymerisation. Hollow fibre membranes were soaked in an aqueous monomeric solution, rinsed and irradiated while submerged in oil. This procedure confined the hydrogel to the void internal volume of the pores of the membrane. Hydrogels of polyacrylamide and polyHEMA, at 0.1 M, 0.5 M and 1 M concentrations and 1 mol% and 10 mol% crosslinker, were synthesized by irradiation at 10 kGy. Hydraulic permeability and diffusion of glucose, albumin and IgG were measured in the hydrogel-filled membranes. Polyacrylamide 0.5 M showed the best compromise between albumin diffusion (1.2 x 107 cm2/s) and HSA / IgG selectivity (2.2).