Preparation Of Membrane Adsorber And Its Application In Monoclonal Antibody Purification

The Monoclonal antibody,or m Ab for short,has been widely used in disease diagnosis,treatment and other fields.Chromatography is the most commonly used method in the purification process of m Ab at present,but the traditional column chromatography has the problems of long operation time and high operating pressure,which are the main reasons for the high cost and low yield of m Ab.Membrane chromatography has the characteristics of high mass transfer rate,low system pressure and easy scale-up,and can be used in the purification process of m Ab instead of column chromatography.Membrane adsorbers are the core of membrane chromatography which consists of membranes coupled with special ligands.Ideal membrane adsorbers should have good reusability.At present,the basic membranes of membrane adsorbers are mostly regenerated cellulose materials,which have poor physical and chemical stability and are difficult to reuse;while hydrophobic membranes such as polyvinylidene fluoride(PVDF)with high mechanical strength and good stability are chemically inert and cannot be directly covalently linked to ligands.In order to prepare membrane adsorbers with good reusability,it is necessary to use basic membranes with high physical and chemical stability and high reactivity,but the existing membrane materials are difficult to take into account both.Treating membranes with good stability to have active groups that can couple ligands is the best choice for preparing ideal membrane adsorbers.In this paper,by comparing various membrane treatment methods,the mild and widely applicable polydopamine deposition modification technology was used to construct the reactive layer on membranes,reusable membrane adsorbers were prepared and the performance of membrane adsorbers was tested during the process of m Ab.In this paper,anion-exchange membrane adsorbers were prepared with polyethyleneimine as ligand,and bovine serum albumin was used as a model impurity protein to simulate the purification process of m Ab.The effects of four membrane treatment methods on the performance of membrane adsorbers were investigated,including ligand adsorption treatment,alkali treatment,oxidation treatment and basic membrane modification,and the membrane modification conditions and operating conditions were optimized.The experimental results show that the protein adsorption and desorption performance of the membrane adsorbers prepared by polydopamine deposition modification is the best.The optimal membrane modification conditions were as follows: the p H value of polydopamine deposition was 8.7,the deposition time was 6 h,the deposition temperature was 25 ℃,the molecular weight of ligand was 70,000,and the concentration of ligand was 15 g/L.The optimal operating conditions were as follows: the p H value of the adsorption buffer was 7.5 and the concentration of Na Cl was 0 m M,the p H value of the desorption buffer was 7.5 and the concentration of Na Cl was 1000 m M.Under optimal conditions,the dynamic binding capacity of membrane adsorbers can reach 49.1 mg/m L,and the desorption rate is 92%.After 5 cycles,the performance of membrane chromatography has no obvious decline,and it has good reusability.