Yang Wang,Guangchuan Wang,Yun Xiao,Yuling Yang,Ruikang Tang
Recent developments of nanotechnology encourage novel materials for facile separations and purifications of recombinant proteins, which are of great importance in disease diagnoses and treatments. We find that Fe3O4@NiSiO3 with yolk–shell nanostructure can be used to specifically purify histidine-tagged (His-tagged) proteins from mixtures of lysed cells with a recyclable process. Each individual nanoparticle composes by a mesoporous nickel silicate shell and a magnetic Fe3O4 core in the hollow inner, which is featured by its great loading efficiency and rapid response toward magnetic fields. The abundant Ni2+ cations on the shell provide docking sites for selective coordination of histidine and the reversible release is induced by excess imidazole solution. Because of the Fe3O4 cores, the separation, concentration, and recycling of the nanocomposites become feasible under the controls of magnets. These characteristics would be highly beneficial in nanoparticle-based biomedical applications for targeted-drug delivery and biosensors.
Yang Wang,Yingying Wei,Qianrui Xu,Shimin Shao,Hong Man,Yingrui Nie,Zhifei Wang,Yong Jiang
Magnetic materials perform well in the purification of histidine-rich proteins (His-proteins). In this work, a facile fabrication of yolk–shell magnetic Fe3O4@NiSiO3/Ni microspheres for the efficient purification of His-proteins has been reported. Yolk–shell Fe3O4@NiSiO3 microspheres were prepared via hydrothermal reaction. Then Ni nanoparticles (NPs) were loaded on Fe3O4@NiSiO3 microspheres after the adsorption and in situ reduction of nickel acetylacetonate. The yolk–shell Fe3O4@NiSiO3/Ni microspheres had a hierarchical flower-like structure and large cavities. The size of the cavity depended on the reaction time. This indicated that the microspheres had a large specific surface area for loading of more Ni NPs, which was crucial to the high His-protein adsorption capacity of Fe3O4@NiSiO3/Ni microspheres. Fe3O4@NiSiO3/Ni microspheres had a high adsorption capacity for bovine hemoglobin (BHb, 2822 mg/g), which was better than the values of other His-protein adsorbents. Fe3O4@NiSiO3/Ni microspheres still had a high BHb separation efficiency after seven separation cycles, indicating its good reusability and stability. Therefore, the as-prepared bifunctional yolk–shell Fe3O4@NiSiO3/Ni microspheres exhibited great practical application value for His-protein purification.