| Glycopolymer refers to the sugar components by means of the introduction of different chemical reactions to form the polymer chain functional polymers. The sugar-based polymers can improve the hydrophilicity, biocompatibility and biodegradability, which were prepared in biology, medicine and many other features with a variety of special-purpose materials, so synthesising of sugar polymers caused by scholars from various countries attention. Preliminary results show that, copolymerization, blending method was introduced into the sugar monomer in polyacrylonitrile ultrafiltration membranes, which can significantly improve the internal hydrophilic polyacrylonitrile membranes and biocompatibility, and extend its biological prospects for biomedical applications.We chose glucose as a model in the thesis, developing a simple and convenient preparation of sugar polymer nanofiber membrane method. Poly-OVSEG and Poly (AN-co-OVAG) were synthesized though the water phase precipitation polymerization, and they were characterized by a variety of means to confirm its structure. The morphology of nanofiber membrane was studied by SEM. The biocompatibility of nanofiber membrane was proved by the hydrophilic test, BSA adsorption, adhesion of macrophages and other experiments testing. On this basis, the nanofiber membrane was used for studying behavior of enzyme immobilization. Study includes the following aspects:(1) Preparation of glycopolymerThe chemo-enzymatic method was introduced to synthesis glucose vinyl esters,and then the glycopolymer Poly-OVSEG and Poly (AN-co-OVAG) were synthesized by a water phase precipitation polymerization process.Through studying of the initiator concentration, monomer concentration, reaction temperature, reaction time on the polymerization reaction, the polymerization conditions were optimized. The structure of product was characterized by infrared spectroscopy (FT-IR), nuclear magnetic resonance (1H NMR,13C NMR) methods and Element analysis. And molecular weight was confirmited by the viscometer method.(2) Preparation of nanofibrous membranesAppling of electro-spinning method, the PAN/Poly-OVSEG, Poly (AN-co-OVAG) and Poly (AN-co-OVAG)/MWCNTs were electrospun into nanofibrous membranes. We studied nanofibrous membranes by SEM characterization. Through the optimization of spinning conditions, these materials can be prepared into nanofibrous membranes. Fiber diameter is 200～500 nm.(3) Biocompatibility testingApplication of contact angle, water absorption test, protein adsorption, adhesion of macrophages and other experiments confirmed that the introduction of the sugar polymerization of acrylonitrile copolymer (AN-co-Polymer) the hydrophilic membrane biocompatibility is improved. Experimental studies have shown that:As fat content increased glucose vinyl film material from the contact angle of PAN nanofiber membranes 65.5°down to 42°(ethylene glucose to fat content of 30.0%); water absorption capacity from 2.3 mg/g to the 3.10 mg/g; BSA adsorption capacity increased from 0.31 g/m2 down 0.1 g/m2; and adhesion of macrophages to reduce the large volume. Through the above experiments we show that the biocompatibility of acrylonitrile copolymer (AN-co-Polymer) has been improved.(4) Immobilization of enzymeThe process of activating hydroxyl for enzyme immobilization is similar to the carboxyl group with the amino coupling. With epichlorohydrin as the coupling agent, the catalases were fixed onto the PAN/Poly-OVSEG, Poly (AN-co-OVAG) and Poly (AN-co-OVAG)/MWCNTs nanofiber membrane. The Quantity, the activity and the stability of the immobilized enzyme was studied. Carbon nanotubes have excellent electrical conductivity, as electron transfer media to effectively promote electron transfer. The multi-walled carbon nanotubes (MWCNT) and Poly (AN-co-OVAG) were blended and the resulting composite nanofiber membrane is good carrier for hydrogen peroxide oxidoreductase. Experimental studies have shown that the stability of the immobilized enzyme was significantly higher than the free enzyme. |
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