Novel polymer blends for the preparation of membranes for biohybrid liver systems

It was found previously that membranes based on co-polymers of acrylonitrile (AN) and 2-acrylamido-2-methyl-propansulfonic acid (AMPS) greatly stimulated the functionality and survival of primary hepatocytes. In those studies, however, the pure AN-AMPS co-polymer had poor membrane-forming properties, resulting in quite dense rubber-like membranes. Hence, membranes with required permeability and optimal biocompatibility were obtained by blending the AN-AMPS co-polymer with poly(acrylonitrile) homopolymer (PAN). The amount of PAN (P) and AN-AMPS (A) in the blend was varied from pure PAN (P/A-100/0) over P/A-75/25 and P/A-50/50 to pure AN-AMPS co-polymer (P/A-0/100). A gradual decrease of molecular cut-off of membranes with increase of AMPS concentration was found, which allows tailoring membrane permeability as necessary. C3A hepatoblastoma cells were applied as a widely accepted cellular model for assessment of hepatocyte behaviour by attachment, viability, growth and metabolic activity. It was found that the blend P/A-50/50, which possessed an optimal permeability for biohybrid liver systems, supported also the attachment, growth and function of C3A cells in terms of fibronectin synthesis and P-450 isoenzyme activity. Hence, blend membranes based on a one to one mixture of PAN and AN-AMPS combine sufficient permeability with the desired cellular compatibility for application in bioreactors for liver replacement.