Discussion On Biocompatibility Of Phytic Acidified Silica Nanoparticles And Its Application

With the rapid development of nanotechnology,functionalized nanomaterials have been widely used because of their unique nature and structure.Silica is one of the popular materials among the inorganic materials.The aggregation of silica has been improved by the modification of silica surface.Thus silica exhibits a very important application prospect in the field of clinical diagnosis,drug release and biomarker.However,according to the reports in literature,the biocompatibility of SiO2 NPs is not very satisfactory.Improving the biocompatibility of silica has been an urgent problem.In this paper,silica nanoparticles(SiO2 NPs)were obtained by the method of water-in-oil(W/O)micro-emulsion.Then amino-groups were modified to the surface of the nanoparticles.Finally,phytic acid(PA)was modified by the hydrogen bonding and electrostatic interactions and silica-phytic acid nanoparticles(SiO2-PA NPs)wereobtained.Transmission electron microscopy(TEM),energy dispersive spectrometer(SEM-EDS),Zeta potential,infrared spectroscopy(IR),nuclear magnetic resonance(NMR)and X-ray photoelectron spectroscopy(XPS)were used to study the morphology and structure of the SiO2-PA NPs.Quantum chemical calculation was used to discuss the interaction between PA and SiO2 NPs in theory.The interaction between SiO2-PA NPs and glucose oxidase(GOx)was studied by UV-visible spectroscopy(UV-vis),infrared spectroscopy(IR)and circular dichroism(CD).In addition,activated partial thromboplastin time(APTT),prothrombin time(PT)and thrombin time(TT)of rabbit blood were measured to evaluate the anticoagulant properties of SiO2 NPs and SiO2-PA NPs.Hemolysis ratio was calculated and morphology of blood cells was observed to assess the material impact on blood cells.Furthermore,cytotoxicity assays explored the cytocompatibility of SiO2-PA NPs.Finally,SiO2-PA NPs were assembled to the electrode surface and a series of electrochemical tests and sample detections were measured.Experimental results are as follows:(1)SiO2-PA NPs have uniform size,good dispersion and electronegativity.And the results of NMR spectra and quantum chemical calculation prove the stable binding of PA and SiO2 NPs.(2)Weak interactions were proved between SiO2-PA NPs and GOx.The secondary structure of GOx is well maintained and the active center of GOx is not destructed.(3)Phytic acid can improve the anticoagulant properties of SiO2 NPs.Hemolysis rate which caused by SiO2-PA NPs is smaller than SiO2 NPs.The morphology of blood cells treated with SiO2-PA NPs is maintained.Meanwhile,the cytotoxicity of SiO2 NPs is reduced significantly.(4)The electrochemical studies show that SiO2-PA NPs provide a friendly microenvironment to GOx and maintain the activity of GOx.GOx/(SiO2-PA NPs)/GCE biosensor also has good electrochemical performance.In summary,the modified phytic acid can improve the dispersion and biocompatibility of SiO2 NPs.Thus the results provide the theoretical and experimental basis for the application in biomedical field of SiO2-PANPs.