The Synthesis Of Zwitterionic Polymer And It's Study In Drug Delivery

The chemical essence of biological enzyme,antibody and vaccine are proteins,whose structures and properties are easily affected by physical and chemical factors.Therefore the protein goes bad,which means their biological activity would be significantly reduced or completely lost.So,looking for some effective methods to maintain the stability of protein's function and structure is one of the key issues needed to be solved in modern chemistry.Zwitterionic polymers have both acidic and basic groups and is hydrophilic,which makes it potential material in keeping the stability and biological activity of protein.In this paper,four different segment copolymers(PMPC-b-PCBMA)were synthesized with 2-methacryloyloxyethyl phosphorylcholine(MPC)and carboxybetaine methacrylate(CBMA)using 4-cyanovaleric acid(ACVA)as the initiator via reversible addition-fragmentation chain transfer polymerization(RAFT)methods.And copolymers structures have been identified by 1H-NMR,FTIR and GPC.The experiments show that zwitterionic block polymers and zwitterionic polymers can effectively maintain the conformation of proteins and keep their biological activity.GOD's biological activity decreases obviously when the temperature is above 45?.In this article we use PCBMA and it's block polymer PMPC-b-PCBMA to study the effect of zwitterionic polymer in maintaining the activity of GOD.In 50?,when adding PCBMA100 and PMPC-b-PCBMA200 to GOD solution 12h later,their activity are 0.52 and 0.396,however the blank sample is 0.242 comparing to its initial activity.When the temperature is 60?,their activity are 0.4352 and 0.391 12h later,however the blank sample is 0.215 comparing to its initial activity.In higher temperature,the effect of the polymer in maintaining GOD activity is more obvious.In conclusion,synthesize zwitterionic polymers can be used to increase protein preservation time.Here,we study the slow release performance of protein in zwitterionic hydrogel.Zwitterionic hydrogel has been synthesized using MPC,PEGDMsso and APS and bovine serum albumin(BSA)is the model drug.The results show that hydrogels with different crosslinking degrees have obvious differences in delivering BSA.The higher the content of cross-linking agent is,the smaller the hydrogel aperture and lower the releasing rate of protein.The research lays foundation to zwitterionic hydrogel controlled releasing protein drug,which has a certain application prospect.