Prepration And Characterization Of Nano-Ag/Sodium Alginate Composite Film

The excellent antibacterial property of nano-Ag, as well as its selective-restrain effect on cell proliferation caused interests of applying it on human implants besides present application of external antimicrobial. For example, apply it on human vascular stent to avoid restenosis. In the sake of apply nano-Ag on different kinds of implant surface, and reduce the security problem caused by the use of nano particles, sodium alginate (AGS) was considered to be used as the carrier of nano-Ag in this study. Via controlling the releasing rate of nano-Ag from the film, the local concentration of Ag can be continuously maintained to a certain level, which is benefit to reducing the harm of aggregation and immigration of nano-Ag while inhibiting the cell proliferation.In this paper, nano-Ag/AGS composite film is prepared on glass substrate by spin coating method, using the nano-Ag and 2.5 w.t.% AGS mixture as the sol. By using X-ray diffraction (XRD), X-ray energy spectra (EDS), Scan electronic microscopy (SEM), Atomic force microscopy (AFM), UV-Spectrophotometry, andⅣmeasurement method, the distribution of nano-Ag in the film, the surface morphology of the film, the electronic property and releasing property of the films are studied. Meanwhile, the cell proliferation behavior on the films was study by MTT assay, and the acute cytotoxicity of the films was studied by LDH as well. The releasing mechanism and the inhibition effect of the film are discussed in detail..The results show that:The nano-Ag/AGS composite films prepared here are uniform, with the thickness of 1μm. The films have Ohmic contact property, whose resistance is increasing with the increase of Ag doping concentration, which matches the model of Maxwell's theory of effective media. The surface morphology is rough with concavities. The distribution of Ag is generally uniform and follows the shape of the concavities. The releasing mechanism of the films is erosion, and the releasing rate is related to the concentration of nano-Ag and the solution. The released nano-Ag partly exists in the chips peeled from film, and its total amount is increasing with its doping concentration. The releasing rate of Ag is different among simulate body fluid (SBF), cell culture medium without bovine albumin, and medium with bovine albumin, which is low in SFB and high in medium with bovine albumin. Nano-Ag/AGS films have significant effect on the restrain of cell proliferation, and the reason can be attributed to the interaction between the released nano-Ag particles, and the influence of the peeled chips.