Affinity membrane development from PBT nonwoven by photo-induced graft polymerization, hydrophilization and ligand attachment

Nonwoven fabrics are of great interest as potential materials for bioseparations due to their interconnected porous structure, relatively high surface area and low cost. In this paper we focus on the development of a potentially disposable affinity membrane for pathogen removal from biological systems such as human plasma. Poly glycidyl methacrylate (polyGMA) was grafted on the fiber surface of a polybutylene terephthalate (PBT) nonwoven using photo-induced graft polymerization. SEM and FTIR were used to characterize the pore structure and surface chemistry of the resulting material. To minimize nonspecific protein binding and hydrophilize the material, diethylene glycol (DEG) and diol groups were attached covalently to the grafted layer of polyGMA. The amount of nonspecific binding was quantified by the adsorption of bovine serum albumin (BSA) and an E. coli extract. The results showed that the grafted matrix containing DEG or diol groups bound significantly less total protein, compared with unmodified material. The DEG modified membrane was further developed by attachment of a specific proprietary ligand that binds to the prion protein, the agent responsible for transmissible spongiform encephalopathies. The affinity membrane showed good selectivity for the capture of prion protein from hamster brain homogenate.