The Surface Of The Nanofiber Membrane Was Grafted To Prepare A Mixed Mode Chromatography Medium

In recent years,protein product has played a significant role in food and healthcare industry.Protein drug has targeting and effective action towards causative agent,such as cancer cells,viruses and so forth.In this way,protein drug is a substitute medicament for the traditional small-molecule drug.However,only protein product with high purity can be dedicated to medicine manufacture.In the process of producing pharmaceutical protein,protein purification accounts for over half proportion of the total production cost.Therefore,an efficient and cost-effective technology should be exploited so as to promote wide application of protein.So far,the material employed to chromatography mostly are silica-based bead and polymeric gel microsphere.Although the chromatography columns can separate protein with high purity of more than 99%,exhibiting extraordinary separation efficiency,they suffer from large pressure drop,low flow rate and high buffer saline consumption due to the dead-end porous structure of microsphere.To overcome the disadvantages of the traditional material,the electrospun nanofibrous membrane can be packed in the chromatography column for separation instead.Because nanofibrous membrane has high porosity and large specific surface attributed to the tortuous inter-connected open path.In addition,some methods to introduce high-density ligand to matrix require harsh reaction conditions,like high temperature,anaerobic condition,or complicated multi-step reaction,which is unpropitious to the demand of wholescale industrial manufacture.In comparison,the aminolysis of anhydride group can react under mild condition,as a versatile platform to introduce various functional groups.In this dissertation,we fabricated nanofibrous membrane using a blend of poly(styrene-alt-maleic anhydride)(SMA)with polyvinylidene fluoride(PVDF)via electrospinning.In the following step,the mixed mode ligand was immobilized on the nanofibrous membrane through the reaction of the anhydride group' with functional amines(n-butylamine,n-octylamine,N-methyl-D-glumine).As a result,three novel membrane adsorbers(designated as PVDFS-g-BAE,PVDFS-g-OAE,and PVDFS-g-NMG separately)with mixed-mode ligands,containing hydrophobic interaction/ion exchange interaction,reverse phase interaction/ion exchange interaction,and hydrophilic interaction/ion exchange interaction respectively,can be developed.The adsorption capacity of PVDFS-g-BAE membrane towards IgG,BSA,Lym were 120 mg/mL,45 mg/mL,25 mg/mL respectively and showed a fair selectivity for IgG;the PVDFS-g-OAE membrane towards a-CTP,CYT-C were 140 mg/mL and 9 mg/mL respectively and showed a remarkable selectivity for a-CTP;the adsortion capacity of PVDFS-g-NMG membrane towards RNase A and PPS were 70 mg/mL and 160 mg/mL respectively.In addition,the nanofibrous membrane has large total pore area,high porosity,and good mechanical property,which are sufficient for the demands of practical use.