Fabrication Of Zinc Oxide Nanowire Arrays And Cytotoxic Study Of The One-Dimensional Nanomaterial

As an important kind of semiconductive material, ZnO nanostructures have been widely applied in various fields, such as field emission and piezoelectricity devices, photocatalysts, and solar cells, and they also exhibit great potential in biology. Aligned ZnO nanowire array can be a powerful tool in dealing with cellular detections and cell manipulation, which makes cytotoxic research on1-deminsional ZnO nanowire arrays important. Recent study on cytotoxicity of ZnO nanowires mainly focuses on several morphological factors, such as dose, aspect ratio, and diameter of ZnO nanowire. However, as a significant factor in affecting creatures, charge effect should also have some impact on cytotoxicity. Consequently, the study on investigating charge effect between one-dimensional nanowire arrays and cells is of great importance to nanotechnology being employed in biology.In this thesis, chemical vapor deposition (CVD) method and hydrothermal method were used to fabricate ZnO nanowire arrays, and factors in influencing the product morphology were investigated. After condition optimization, ZnO nanowire arrays synthesized by CVD methods had an average diameter of800nm, with the average length around20μm ZnO nanowire arrays fabricated by hydrothermal method were30nm in average diameter and2μm in average length.With12-well plate being as the static solution platform, microfluidic devices fabricated by soft lithography being as the dynamic solution platform, and HepG2cancer cell line as target cells, applicability of the two platforms in doing cytotoxic experiments were analyzed by Live/Dead kit and Hochest33342fluorescent staining. From the results, cells on ZnO nanowire arrays in dynamic solution platform showed significant cytotoxicity in a relative short time, exhibiting cell death and filamentous pattern in DNA staining. However, cells adhered on ZnO nanowire arrays were more in quantity than on glass substrates in static solution platform, and the cells were in good condition. The results indicated static solution platform was suitable for further cytotoxic experiments.I investigated the influence of charge effect between nanowire arrays and cells on cytotoxicity. ZnO nanowire arrays synthesized by hydrothermal method were employed as experimental substrates, and charge quantity on surface of the nanowire arrays was tuned by altering PEI content in growth solution. Three different cancer cell lines were selected as target cells, with Zeta potential characterization to analyze their surface charge density. CCK-8kit was applied to preciously determine cell viability. Live/Dead kit was used to intuitively observe cell death. SEM was employed in order to show cell morphology. Intracellular ROS and GSH were used to reflect apoptosis. From results of cytotoxic experiments, I confirmed one-dimensional of the ZnO nanowire arrays was the chief factor induced cytotoxicity. Cytotoxic degree related with charge effect, and cytotoxicity increased with the enhancing of charge effect. Cytotoxicity also exhibited time-dependent, with longer time leaded to greater cytotoxicity.