Polymer Microsphere Surface Molecule Graft And Biochemical Affinity Property

Affinity polymer latex microsphere is a kind of functional polymer microsphere, which has affinity molecules or groups on its surface to efficiently recognize and separate the target molecules by the high specific surface areas of the microsphere. There are high degree of specific recognition and coordination between affinity molecules and target molecules. These objects mainly include drug-receptor, antibody-antigen, complementary DNA chains, etc. Affinity polymer latex microspheres have the common advantages of functional polymer microspheres, i.e., stable dispersion, large specific surface areas as well as versatile properties. In addition, these smart latex microspheres have several particular features, such as well mechanical performance, sensitivity, excellent biology compatibility, easy to recovery and repetitious to use, friendly to environment. Affinity polymer latex microspheres showed potential application for bioseparation, antibody identification, DNA diagnosis as well as efficient evaluation of medicine. For example, the affinity microspheres hold the bio-inert and high surface area can be used for identification, separation and purification of drug receptor from biological tissue by immobilizing the drug molecules on its surface. Expand the ideals of new drugs development and shorten the drug development cycle by studying the mechanism of drug and drug receptor.Poly (styrene-co-glycidyl methacrylate) (PSG) latex microspheres with epoxy groups on its surface are prepared by soap-free emulsion polymerization with hydrophobic monomer styrene and glycidyl methacrylate. The PSG microspheres are modified with 1,6-hexanediamine space arm to reduce the steric hindrance and side interaction of the surface and the amino-modified microsphere PSGN was obtained. The content of amino groups on PSGN particle is measured by elemental analysis and 4-nitrobenzaldehyd methods. Then the pemetrexed disodium (MTA) is covalent immobilized on the surface of the PSGN particles through the amidation between the carboxylic acid end group of MTA in acidic medium and the amino groups on the PSGN particle surface. The experimental results suggest MTA immobilization is mainly dependent upon both the particle size and active amino groups on the PSGN surface. The amino group density of the PSGN microsphere surface could be controlled through altering the ratio of feed and the mode of operation. Further, the immobilization of MTA is also controllable. Researches on the influence of pH, temperature and the different ratio and concentration of catalysts on MTA coupling reaction are performed and the optimum reaction conditions are earned.The adsorption property of BSA protein onto the surface of polymer microsphere drug is emphatically studied. Bovine serum albumin (BSA) is selected as the model protein. The effect of pH, ion concentration and different first BSA concentration on adsorption is emphatically examined. The results showed the higher covalent immobilization concentration and uniform distribution of MTA on the polymer microspheres have the regular adsorption process of BSA protein. The process of BSA protein adsorption onto polymer latex microsphere drug accords with the first order kinetics under ideal condition. Electrostatic attraction plays an important role in the BSA adsorption.