磁芯负载离子液体凝胶微球的制备、表征及在固定化细胞技术中的应用

Preparation,Characterization of Magnetic Core Gel Microspheres Loaded Ionic Liquids and Its Application in Cells Immobilization Technique

选取具有良好生物相容性的壳聚糖(CS)包覆四氧化三铁纳米粒子(Fe_3O_4/CS)作为磁响应材料,制备了磁芯负载1-丁基-3-甲基咪唑六氟磷酸盐([BMIM]PF_6)凝胶微球;对Fe_3O_4/CS及磁芯负载离子液体凝胶微球的组成、结构、微观形貌和磁性能进行了表征;将其应用于固定化细胞技术,在产紫青霉细胞全细胞生物催化甘草酸(GL)合成单葡萄糖醛酸基甘草次酸(GAMG)体系中,实现了对全细胞生物催化剂和离子液体的快速回收和重复利用.实验结果表明,壳聚糖成功包裹Fe_3O_4纳米粒子; Fe_3O_4/CS均匀分布在凝胶微球内部,并显示出良好的磁性能;与凝胶微球固定化细胞催化体系相比,磁芯负载[BMIM]PF_6凝胶微球固定化细胞催化体系中GAMG的产率提高了13. 8%;重复利用实验结果表明,磁芯负载[BMIM]PF_6凝胶微球固定化产紫青霉细胞在外加磁场的作用下,易于快速回收,并且循环再利用9次后相对活性仍保留59. 2%.

The magnetic core gel microspheres loaded ionic liquids(ILs)were prepared using Fe3O4 nanoparticles coated with chitosan with good biocompatibility(Fe3O4/CS)as magnetic response material.The composition,structure,morphology and magnetic properties of the prepared Fe3O4/CS nanoparticles and magnetic core gel microspheres loaded[BMIM]PF6 were characterized by Fourier transform infrared spectroscopy(FTIR),scanning electron microscope(SEM),transmission electron microscope(TEM),X-ray diffraction(XRD),thermogravimetric analysis(TG)and vibrating sample magnetometer(VSM).And the magnetic core gel microspheres loaded[BMIM]PF6 was applied to immobilize Penicillium purpurogenum Li-3 cells for the biosynthesis of glycyrrhetinic acid monoglucuronide(GAMG)from glycyrrhizic acid(GL)to realize the rapid recovery and reuse of the whole-cell biocatalyst and ILs.The results showed that the Fe3O4 nanoparticles were successfully encapsulated by chitosan.And due to the uniform distribution of magnetic particles in the prepared gel microspheres loaded ILs,the microspheres show good magnetic properties.Compared with immobilized cells with gel microsphere(Ic)catalytic system,the yield of GAMG in immobilized cells with magnetic core gel microspheres loaded[BMIM]PF6(IcMILs)catalytic system increased by 13.8%.The reutilization experiment showed that the IcMILs were easier to be recovered quickly under the applied magnetic field.After9 cycles of recycling,the Ic MILs relative activity still remained 59.2%.The preparation technique of the magnetic core gel microspheres loaded ILs has the potential to be further developed and applied in the rapid on-line separation and continuous operation of biocatalyst and ILs to increase the catalytic yield and reduce the cost.