ABSTRACT
The macroporous microspheres were prepared through suspension polymerization and based on a copolymer of glycidyl methacrylate and ethylene glycol dimethacrylate.The effect of porogen on the microspheres structure was evaluated in terms of pore size and surface area.Porogen contained dichloromethane (δ=9.7 (cal/cm3)1/2) and N-octanol (δ=10.3 (cal/cm3)1/2) which corresponded to a good and poor solvent,respectively.The solubility parameter of porogen was controlled in the range of 9.89-10.09 (cal/cm3)1/2.The pore size of microspheres increased with the difference value of solubility parameter between the polymer and the porogen.On the contrary,the surface area of microspheres decreased in this study.The anion exchange media was prepared through coupling poly(ethylene imine) in the microspheres,and the proteins transport was determined by frontal analysis method.The macroporous microspheres with 257 nm pore size could still afford a high proteins capacity (45.1 mg/mL).These macroporous supports showed a large potential in a rapid separation of proteins.
ABSTRACT
Novel hydrophobic absorbents were synthesized by immobilizing butyl derivative onto the highly cross-linked agarose beads manufatured in China, which are used as matrix. The effect of the spacer arm length (3C, 8C and 10C) and ligand density (from 13 to 45 micromol/mL) on the hydrophobicity were investigated using purified Hepatitis B surface antigen (HBsAg) expressed by CHO cell lines. Also considering the effects of salt concentration and pH on HBsAg recovery and purification factor, orthogonal experiment design method was used to evaluated the absorbents. The results showed the butyl-S absorbent with the spacer arm length of C8, the ligand density of 22 micromol/mL gel showed the best performance for the separation of HBsAg. Approximately 100% HBsAg recovery and 60 as purification fold were achieved by this media under the operating condition of pH 7.0 and 9% of salt concentrateion.
Subject(s)
Animals , Cricetinae , Adsorption , CHO Cells , Chromatography, Agarose , Methods , Cricetulus , Hepatitis B Surface Antigens , Hydrophobic and Hydrophilic Interactions , Recombinant ProteinsABSTRACT
A new hydrophobic absorbent based on homemade highly cross-linked agarose beads was synthesized by immobilizing butyl derivative onto the matrix linkage. The density of ligand was controlled by adjusting the concentration of butanethiol and the synthesis route was optimized by evaluating the purification efficiency of recombinant Hepatitis B surface antigen (HBsAg) expressed by Chinese hamster ovary (CHO) cell line. A high performance absorbent was finally screened out with up to 80% of HBsAg recovery and purification-fold (PF) about 20. Furthermore, the column pressure was about 0.06 MPa under the flow rate of 500cm/h, and no leaked butyl were detected after exposing the gel in common buffers, chaotropic agents, high concentrations of denaturing agents such as guanidine hydrochloride, urea and polar organic solvents. These results demonstrated that the absorbent have high physico-chemical stability, so it was available for the downstream process. Finally, after scaled up to 2L wet gel/batch, the absorbent was applied to the integration of three-step chromatography and obtained the purified CHO-HBsAg with 95% purity by SDS-PAGE and HPLC, which meet the requirements of SFDA. The purification efficiency and the reproducible ability of the absorbents were also evaluated from batch-to-batch. The results demonstrated that the absorbent met the requirement of scalable, reproducible, economic effect as well. This absorbent is a promising alternative exported HIC gel for wildly being used in Chinese pharmaceutical industries.
Subject(s)
Animals , Cricetinae , Humans , CHO Cells , Chromatography, Agarose , Methods , Cricetulus , Hepatitis B Surface Antigens , Genetics , Recombinant Proteins , GeneticsABSTRACT
The dissociation of virus-like particles of Hepatitis B surface antigen (HBsAg) during the adsorption-desorption on the solid-phase of chromatography is a main challenge for its purification. Herein, poly (ethylene glycol) (PEG) was applied as an additive during the purification of HBsAg from recombinant Chinese hamster ovary (CHO) cell culture to improve the HBsAg recovery and protect its structural assembly. The presence of 1% of PEG10000 in the mobile phase of ion-exchange chromatography (IEC) of DEAE-Sepharose FF column could increase the recovery of HBsAg from about 55% to 80%, with a similar purification (-fold) (about 12) compared with the absence of PEG. Importantly, glycosylated protein forms of HBsAg were reserved well by PEG-accompanied chromatography. Furthermore, size exclusion chromatography-multiangle laser light scattering (SEC-MALLS) analysis was performed on line to monitor the aggregates, particle size and molecular weight distribution of HBsAg. The results demonstrated that the HBsAg particle size and assembly are more homogenous after adding PEG in the mobile phase of IEC than no PEG added in the mobile phase.