Bifunctional Polysulfone-Chitosan Composite Hollow Fiber Membrane for Bioartificial Liver

Hollow fiber membranes are widely used as assist devices for bioartificial liver application. Asymmetric porous polysulfone and polysulfone-tocopheryl polyethylene glycol succinate (Psf-TPGS) composite hollow fiber and flat membranes were prepared by phase inversion procedure and subsequently surface modified with chitosan using sulfonation with concentrated sulfuric acid. Sulfonation induces negative charge on the prepared membrane surface and facilitates the attachment of chitosan amine groups by electrostatic interaction. The surface modification of membrane is stable at room temperature as dictated by presence of nitrogen in XPS analysis and amide linkages in FT-IR spectra. Further, biological studies of the membranes were performed using HepG2 cell line. Chitosan is biocompatible and shows structural similarity to glycosaminoglycans, a native liver ECM component. The chitosan-modified composite Psf and Psf-TPGS membranes have shown enhanced attachment and proliferation of HepG2 cells on outer surface as confirmed by the cell counting, DNA content, confocal microscopy, and SEM micrographs. The cells form a 3D multicellular spheroid structure on the chitosan-modified membranes in significantly larger number as seen in the SEM micrographs. Also, the hemocompatibility of the modified composite membranes were comparable to the unmodified membranes. Thus, the chitosan-modified composite membranes we have developed are bifunctional and have the potential to be used in bioartifical liver application.