Surface-modification Of Poly(Glycidyl Methacrylate-Divinylbenzene)Microspheres And Its Evaluation As HIC Media For Protein Adsorption

Synthetic polymer is well known for its relatively hydrophobic network, which will undermine the bioactive material during the separating process. In most cases the synthetic media have to be modified to facilitate the process, which is compatible to biomaterial. Poly(glycidyl mathacrylate)(PGMA) is a kind of copolymer with epoxy groups in the network. In that ligands can be easily coupled by the epoxy reaction.In this thesis, rigid porous poly(glycidyl methacrylate-divinylbenzene)[P(GMA-DVB)] microspheres were synthesized through suspension polymerization with a mixture of isooctane and4-methyl-2-pentonal as the porogen. The microspheres were intended to work as column packing materials for protein separation. In order to minimize non-reversible adsorption of proteins, polyethylene glycol (PEG) was coupled onto the microspheres via the reaction with epoxy groups. The reaction process was studied and optimized with respect to the amount of PEG coupling. A new method was invented to determine the density of PEG on the microspheres.Bovine serum albumin (BSA) and trypsin were used as two model proteins to examine adsorption and desorption properties of the modified P(GMA-DVB) microspheres. The modified microspheres have little non-reversible adsorption for BSA and trypsin. The mass recovery and activity recovery are more than97%. The adsorption of protein on the modified microspheres was reversible hydrophobic interaction.PEG-P(GMA-DVB) was packed into column and compared to Phenyl Sepharose CL-4B and Butyl Sepharose4FF from GE in oder to demonstrate its chromatographic behavior. The flow rate-pressure curve of PEG-P(GMA-DVB) was linear(0-0.3MPa) and it implied that, the media had excellent mechanical stability and resistant to high pressure and high flow rate.The modified microspheres can be used for hydrophobic interaction chromatography of proteins.