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Zirconia is commonly used for manufacturing of dental implants thanks to its excellent mechanical, biological and aesthetic properties. However, its bioinertness inhibits bonding with the surrounding hard tissue and other surface interactions. In our study, we present a method for multifunctionalization of zirconia surface to improve its osseointegration and to minimize the infection risks. For this reason, we introduced antibacterial and bioactive properties to zirconia surfaces by calcium phosphate biomimetic coating. The samples were incubated in vials in horizontal and vertical position in concentrated simulated body fluid (SBF) containing 0.1, 0.5, and 3 g/L of silver nanoparticles (Ag-NPs) and then were tested for their structure, surface properties, cytocompatibility and antibacterial properties. The results demonstrated that our method is suitable to introduce Ag-NPs at different concentrations into the calcium phosphate layer, i.e. from 0.05–26.6 atom% as shown by EDX. According to the results of CFU-assay these coatings exhibited antibacterial properties against S. aureus and E. coli in correlation with the concentration of Ag-NP. The potential cytotoxicity of the coated samples was determined by AlamarBlue® assay and live/dead staining of MG63 osteoblast-like cells in direct contact and by testing the extracts from the materials. Only samples containing 0.05 atom% Ag-NPs, i.e. incubated in vertical position at SBF with 0.01 g/L Ag-NPs, were found cytocompatible in direct contact with MG63 cells. On the contrary in the indirect tests, the extracts from all the materials were found cytocompatible. This method could allow developing the completely new material group, exhibiting not only one but several biological properties, which can improve osseointegration and minimize infection risks. [ABSTRACT FROM AUTHOR]

This article discusses the morphology and thermomechanical properties of graphene oxide (GO) paper sheets and GO paper composites reinforced with carbon fibers. GO paper was fabricated using GO paste obtained by the condensation of GO aqueous solution synthesized using the Hummers' method. Carbon fibers were implemented to improve the mechanical properties of the pristine GO paper. All the investigated papers were subjected to thermal treatment to check thermo-related morphological and mechanical properties. The results presented in this study allowed for the deeper insight into morphological, structural, and mechanical volume and surface-related properties of pristine GO and GO-based composite materials reinforced with carbon fibers. We showed that there are two important factors that should be taken into consideration for the design and fabrication of GO-based papers. These factors were the concentration of the reinforcing agent and the thermal reduction of the papers. Both factors have influenced the final properties of the resulting GO-based papers. For the first time, it was revealed how the addition of the reinforcing material affects the GO paper thermal expansion coefficient. [Display omitted] [ABSTRACT FROM AUTHOR]