Preparation Of Zwitterionic Polymer Coating Materials With Epoxy Groups And Resisting Protein Adhesion Performance

Biofouling is usually accompanied by negative effects and the phenomenon occurs in many areas,such as marine and biomedical applications.At present,the marine fouling was mainly prevented by slowly releasing pesticides,but the use of pesticides often leaded to more environmental problems.Medical poly（vinyl chloride）（PVC）have been extensively used as extracorporeal circulation device due to its excellent physical and mechanical properties.However,the surface of medical PVC is hydrophobic,not completely biocompatible and tend to interact with plasma proteins,leading to thrombus formation.Aiming at this problem,this study prepared zwitterionic polymers with epoxy groups and modified the stainless steel and PVC surfaces.The structure of modified surface coating and the performance of resistance to bovine serum albumin were characterized.Firstly,the sulfobetaine amphoteric monomer（SBMA）was synthesized by the ring opening reaction of the 2-（dimethylamino）ethyl methacrylate（DMAEMA）and1,3-propane sultone（1,3-PS）.Then the zwitterionic polymer with epoxy group was prepared by free radical polymerization with SBMA and methyl methacrylate（GMA）.And the structure of the monomer and polymer was characterized by IR and¹HNMR.Secondly,with stainless steel as base,three kind of zwitterionic coatings,includingS-OH/APTES/PSG_20/2,S-OH/DP/APTES/PSG_X/Yand S-OH/（DP/TEOS）/APTES/PSG_X/Y,were prepared by three-step method.Firstly,the hydroxylating stainless steels were soaked in DP Tris-HCl buffer solution or DP/TEOS mixed solution or Tris-HCl buffer solution in order to form bottom layer on the stainless steels.Secondly,the samples were soaked in the toluene solution of APTES forming the silicon layer with reactive groups.Finally,the samples were soaked in the phosphatic buffer solution of zwitterionic polymer PSG_X/Y/Y with epoxy group for purpose of forming zwitterionic coating on thestainless steels.The surface morphology,chemical structure and composition of the coated stainless steel were characterized by SEM,ATR-FTIR and SEM-EDS.Experimental results showed that the zwitterionic coating was successfully formed on stainless steel surface by the three-step method.The bovine serum albumin（BSA）adsorption test was carried on the coating.The protein adsorption amounts of S-OH/DP/APTES/PSG_20/2（8.64ug/cm²）in the condition of the reaction time of 24 hours and the toluene solution of APTES of 30 mg/mL,and S-OH/APTES/PSG_20/2（7.92 ug/cm²）were similar,better thanS-OH/（DP/TEOS）/APTES/PSG_20/2.Moreimportantly,incontrast,S-OH/DP/APTES/PSG_20/20/2 not only had the resisting corrosion advantage of polydopamine,but also had the performance of the double resisting protein adsorption from the silicon layer and zwitterionic polymer.So,the surface modification method on stainless steel sheet in this study has potential application prospect in the field of marine.Finally,This paper tried to prepare zwitterionic coating on the surfaces of PVC or PVC-OH by using a two-step method.Firstly,the PVC or PVC-OH were soaked in the mixed-solution of DP and APTES in order to form composite membrane on the PVC surface.Secondly,the composite membranes were soaked in the phosphatic buffer solution of zwitterionic polymer PSG_20/20/2 with epoxy group for purpose of forming zwitterionic coating on the composite membranes.These coatings were characterized by SEM,ATR-FTIR,SEM-EDS and Water Contact Angle methods.The results showed that PSG_20/20/2 were grafted to the surface of PVC.The resisting protein adsorption experiment of zwitterionic coating showed that the amount of adsorption of bovine serum albumin（BSA）on the surface of the zwitterionic coating decreased obviously,but needed to be improved further.