Synthesis And Coating Properties Of A Doubly Biomimetic Copolymer Bearing Both Adhesive Catechol And Anti-biofouling Phosphorylcholine Functionalities

Mussel can fix themselves onto kinds of organic,inorganic,nature and synthesis material’s surfaces.A doubly biomimetic polymer Catechol-g-P(MPC-MEONP)(PMNC)bearing cell antifouling phosphorylcholine and mussel adhesive protein catechol groups was synthesized.The polymer can be deposited onto a variety of substrates by dip coating in an aqueous solution,adhering to surfaces via the catechol functional group while at the same time forming a cell outer membrane mimetic antifouling surface.The main content of this paper contains:(1)Synthesis of the doubly biomimetic copolymer catechol-g-P(MPC-MEONP)(PMNC).The synthesis of the doubly biomimetic copolymer includes three steps:1)the monomer p-nitrophenyloxycarbonyl poly(ethylene glycol)methacrylate(MEONP)was synthesized via a acylation reaction between p-nitrophenylchloroformate and poly(ethylene glycol)methacrylate;2)P(MPC-MEONP)(PMN),which contains active ester groups,is synthesized by conventional free radical copolymerization of 2-methacryloyloxyethyl phosphorylcholine(MPC)and MEONP;3)the p-nitrophenyloxycarbonyl groups of PMN were reacted with dopamine to install catechol groups.Three series of PMNC polymers were prepared and characterized by 1H-NMR,GPC and UV-vis spectroscopy.The total yields were from 45%to 55%with Mn of 10000-20000 Da.(2)Construction and properties of doubly biomimetic polymer coating.The doubly biomimetic copolymer PMNC was coated onto cover glass,polycarbonate,poly(propylene),poly(tetrafluoroethylene)and stainless steel 304 substrates by dip coating in an aqueous solution of PMNC.Moreover,a cell outer membrane mimetic surface/interface was formed automatically endowing the anti-biofouling of cell membrane.Dynamic contact angles and static contact angle measurements showed that all the PMNC coated substrates had roughly the same contact angles,displaying the property of the PMNC coating.ATR-FTIR and XPS measurements confirmed the polymer coating formation and the cell outer membrane structure.The stability of the coating was tested by dipping in distilled water for 24h,75%ethanol for 6h,and then 1%SDS aqueous solution with ultrasonication for 30 minutes.The dynamic contact angles of the surfaces showed non obvious change,suggesting a strong adhesion of the mussel mimetic copolymer.(3)Biocompatibility of the PMNC coating.The cytotoxicity of the doubly biomimetic PMNCs was investigated by the incorporation of L929 cells in different concentrations of PMNC.Over 95%viability of the cells indicated that the doubly biomimetic PMNCs are not toxic.Protein adsorptin amounts of BSA and Fg on PMNC coated surfaces of cover glass,polycarbonate and stainless steel 304 substrates were reduced by more than 90%compare with the bare surfaces.Even on the highly drophobic surface of PTFE substrate,BSA adsorption reduced by 38%,Fg reduced by 62%.Platelet adhesion from human serum onto all the coated substrate surfaces were completely suppressed,suggesting an excellent hemocompatibility.Cell adhesion of L929 on PMNC coated surfaces were reduced by more than 90%.All the results demonstrated that the anti-biofouling property of the doubly biomimetic copolymer coatings were excellent.This easy strategy of fabricating anti-biofouling surfaces by dip coating in an aqueous solution of PMNC can be used to coat various materiales which precisely controlled functionalities.Furthermore,this doubly biomimetic copolymer strategy can be extended to other functionalities,offering simple yet versatile alternatives to more complicated and aggressive chemical and physical methods of surface modification for medical and nonmedical applications.