(370d) Reduction of Nonspecific Protein Adsorption On Nonwoven Fabrics by Hydrophilization After UV-Induced Surface Graft Polymerization

Surface-modified nonwoven fabrics are of interest as potential novel membranes for various steps in bioseparations due to their controllable porosity, surface area and relatively low cost. A precursor monomer glycidyl methacrylate (GMA) was grafted on the surface of polybutylene terephthalate (PBT) nonwoven fabrics using UV-induced graft polymerization. The GMA grafting conditions were optimized to achieve a uniform grafting layer around the fibers. The GMA grafting weight gain increases with the grafting time and monomer concentration. Scanning electron microscopy (SEM) and attenuated total reflectance Fourier transform infrared (ATR-FTIR) were used to confirm the presence of the grafting layer.

Diethylene glycol (DEG) groups were covalently attached to the GMA layer on these fabrics and hydrolysis of the GMA with water was used to created diol groups on the fiber surface. The ability of the nonwoven fabrics to bind bovine serum albumin (BSA) was examined with different GMA weight gains followed by attachment of DEG or diol groups. As the GMA weight gain increases, the amount of protein binding was reduced dramatically and reached a constant low value at weight gains above 10%.

BSA protein binding isotherms were measured on blank PBT, PBT-GMA-DEG, PBT-GMA-diol, UV/O treated PBT and plasma treated PBT. The results show that nonspecific protein binding was reduced around 20% with UV/O treatment alone, around 50% with plasma treatment alone and around 90% after GMA grafting and DEG or diol conversion. The adsorption of lysozyme, â-casein and hIgG were also measured. The results show that nonspecific protein binding after hydrophilization (after DEG or diol attachment) was reduced by about one order of magnitude compared with the original PBT nonwoven fabrics. In future work, DEG on the surface can be used as a spacer arm to create affinity membranes with very low nonspecific protein binding.