Study On The Application Of Functionalized Silica Coated Magnetic Nanoparticles In Protein Separation

As the development of protein separation, it is important to exploit effective and stable adsorbents, which can be separated quickly and easily. As a kind of new functionalized nanomaterials, silica coated magnetic nanoparticles have received more and more attentions in the field of bio–separation for their biochemical stability, large surface area, unique magnetic property and good biocompatibility. In this study, we exploited functionalized silica coated magnetic nanoparticles as different kinds of protein adsorbents in separation of proteins with eletrostatic adsorption and affinity adsorption principles respectively. This study provides new adsorbents and techniques for the separation of proteins, and furtherly explored the application of functionalized silica coated magnetic nanoparticles in biomedicine.1.Research on acidic proteins separation with the adsorbents based on amino–silica coated magnetic nanoparticles.The amino–silica coated magnetic nanoparticles were used as pH–dependent protein adsorbents, the zeta potentials of which were different at different pH. The adsorption performance and equilibrium isotherm of the adsobents were studied with BSA as representation for acidic protein. The effects of solution pH and ionic strength on the adsorption between the adsorbents and acidic proteins and the maximum adsorption amount of proteins were studied. The nanoadsorbents with amino–silica coated magnetic nanoparticles carried out to separate BSA and Con A from simple model protein mixtures, which validated the selectivity adsorption ability for acidic proteins of the amino–silica coated magnetic nanoparticles.2.Research on alkaline proteins separation with the adsorbents based on silica coated magnetic nanoparticles.The silica coated magnetic nanoparticles were used as pH–dependent protein adsorbents, the zeta potentials of which were different at different pH. The adsorption performance and equilibrium isotherm of adsobents were studied with Cyt–C as representation for alkaline protein. The effects of solution pH and ionic strength on the adsorption between the adsorbents and alkaline proteins and the maximum adsorption amount of proteins were studied. The nanoadsorbents with silica coated magnetic nanoparticles carried out to separate Cyt–C and IgG from simple model protein mixtures and separate Cyt–C from fresh pig heart, which both validated the selectivity adsorption ability for alkaline proteins of the silica coated magnetic nanoparticles. 3.Research on target protein separation with affinity adsorbents based on biofunctionalized silica coated magnetic nanoparticles.Biofunctionalized silica coated magnetic nanoparticles were developed as affinity protein adsorbents, which were activated with CNBr and modified by biomoleculars. Duo to the differential recognition between trypsin and trypsin inhibitor, they were chosen as representation for the affinity couple. And trypsin inhibitor was modified on the silica coated magnetic nanoparticles. The effects of modification on the size and zeta potential of silica coated magnetic nanoparticles and the midfication efficiency were studied. And trypsin in simple model protein mixture or pig pancreas was objectively separated with the biofunctionalized silica coated magnetic nanoparticles. This study provided a new kind of affinity adsorbents for protein separation with silica coated magnetic nanoparticles, which has magnetic core and biomodified surface.