The Design And Application Of Protein Resistance Polymers Graft Polydopamine Coating

The aim of this paper is to prepare a series of polymer coating materials which not only can adhere onto materials surface by using a simple method, but also have the excellent protein-resistant property. We firstly synthesized a series of polymer with free amine groups, such as:amination of long chain polyethylene glycol (mPEGsooo-NH2), the copolymerization of short chain polyethylene glycol methacrylate (PEGMA300) and2-aminoethyl methacrylate (AEMA) which with free amino groups (poly(PEGMA300-random-AEMA)), as well as the copolymerization of sulfobetaine methacrylate (SBMA) and AEMA (poly(SBMA-random-AEMA)). For the design of such polymers, we intended to utilize the amino groups from the polymers which could react with catechols from polydopamine (PDA) coating via Michael addition or Schiff base reactions under oxidizing conditions, to form an antifouling adlayer on materials surface. In this thesis, our works are described in following:1. We have synthesized the amination of long chain mPEGsooo-NH2(Mw=5000), which can be modified onto capillary inner surface by using PDA adlayer to form mPEG5000-graft-PDA antifouling polymer coating. In our previous works, we know that the mPEG5000-groft-PDA polymer coating exhibits excellent stability and also has the ability to resistant protein adsorption, in order to make full use of the mPEG5000-graft-PDA coating modified capillary, the mPEGsooo-graft-PDA coating modified capillary was used for the quantitative analysis of food proteins, such as egg white proteins and whey protein in nonfat milk powder. In addition, the surface plasmon resonance (SPR) technology was also used to investigate the protein-resistant property of the antifouling coating for the six standard proteins from food proteins. SPR experimental results show that the polymeric coating has excellent protein-resistant performance. By the way, from capillary electrophoresis (CE) experimental results we can see that the polymer modified capillary not only could achieve successfully separation of egg white proteins and the whey proteins, but also could realized the quantitative analysis of proteins exists on egg white proteins and the whey proteins, which has the guiding significance for food product quality inspection in future.2. We have synthesized the copolymer of poly(PEGMA3oo-ranom-AEMA) by atom transfer radical polymerization (ATRP). These copolymers are made up of low molecular weight polyethylene glycol methacrylate (PEGMA300, Mw=300) and AEMA. For the design of such copolymers, the part of AEMA side chains could provide the free amino group which could react with PDA via Michael addition or Schiff base reactions under oxidizing conditions, besides, the content of amino groups can be adjusted by changing the feed ratio, the part of PEGMA300side chains with the low molecular weight of polyethylene glycol could be used to resist protein adsorption. The defined copolymer structure was characterized by nuclear magnetic resonance hydrogen spectroscopy (1H NMR) and gel permeation chromatography (GPC). The chemical component and surface morphology of the brush-like copolymer-graft-PDA coating were studied by using X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM), respectively. The hydrophilicity of the brush-like copolymer-graft-PDA coating was investigated by using static water contact angle. The protein-resistant property of the brush-like copolymer-graft-PDA coating was investigated by using quartz crystal microbalance with dissipation (QCM-D), and finally the coating was applied to capillary inner surface for protein separation by CE.3. We have synthesized the copolymer of poly(SBMA-random-AEMA) by traditional radical polymerization. We look forward to combining SBMA and AEMA to prepare a kind of copolymer which not only could adhere to materials surface by using a simple method, but also could resist protein adsorption. For such copolymers, the part of AEMA side chains could provide the free amino group which could react with PDA via Michael addition or Schiff base reactions under oxidizing conditions, the part of SBMA side chains could be used to resist protein adsorption. The defined copolymer structure was characterized by1H NMR. The chemical component and surface morphology of the zwitterionic copolymer-graft-PDA coating were studied by using XPS and SEM, respectively. The hydrophilicity of the zwitterionic copolymer-graft-PDA coating was investigated by using static water contact angle test. Finally the zwitterionic copolymer-graft-PDA coating could be modified onto capillary inner surface for protein separation study by CE.