Sol–Gel Synthesis and Characterization of YSZ Nanofillers for Dental Cements at Different Temperatures

From MDPI via Jisc Publications RouterHistory: accepted 2021-10-26, pub-electronic 2021-10-29Publication status: PublishedFunder: The project is co-financed by Greece and the EuropeanUnion (European Social Fund-ESF) by the Operational Program Human Resources Development,Education and Lifelong Learning 2014–2020.; Grant(s): MIS5047876Background: Yttria-stabilized zirconia nanoparticles can be applied as fillers to improve the mechanical and antibacterial properties of luting cement. The aim of this study was to synthesize yttria-stabilized zirconia nanoparticles by the sol–gel method and to investigate their composition, structure, morphology and biological properties. Methods: Nanopowders of ZrO2 7 wt% Y2O3 (nY-ZrO) were synthesized by the sol–gel method and were sintered at three different temperatures: 800, 1000 and 1200 °C, and their composition, size and morphology were investigated. The biocompatibility was investigated with human gingival fibroblasts (hGFs), while reactive oxygen species (ROS) production was evaluated through fluorescence analysis. Results: All synthesized materials were composed of tetragonal zirconia, while nanopowders sintered at 800 °C and 1000 °C additionally contained 5 and 20 wt% of the cubic phase. By increasing the calcination temperature, the crystalline size of the nanoparticles increased from 12.1 nm for nY-ZrO800 to 47.2 nm for nY-ZrO1200. Nano-sized particles with good dispersion and low agglomeration were received. Cell culture studies with human gingival fibroblasts verified the nanopowders’ biocompatibility and their ROS scavenging activity. Conclusions: the obtained sol–gel derived nanopowders showed suitable properties to be potentially used as nanofillers for dental luting cement

Effect of ion doping in silica-based nanoparticles on the hemolytic and oxidative activity in contact with human erythrocytes

Aim: The aim of this study was the synthesis of ion doped silica-based nanoparticles and the evaluation of their toxic effect on erythrocytes. Materials & methods: Their synthesis was performed using the sol-gel method, by the progressive addition of calcium, magnesium and copper ions on pure silica nanoparticles. The toxicity evaluation was based on hemolysis, lipid peroxidation, ROS, H2O2 species and antioxidant enzyme production. Results: The addition of Mg and Cu in the SNs presented better hemocompatibility by protecting erythrocytes from oxidative stress. Conclusion: Ion doping with magnesium in the investigated calcium silicate system induces a protective effect in erythrocyte membrane in compare with pure silica nanoparticles

Incorporation of nanosized carbon over hydroxyapatite (HAp) surface using DC glow discharge plasma for biomedical application

Hydroxyapatite (HAp) is a well-known material of choice in numerous biomedical applications such as orthopaedics, dentistry etc., because of its similar configuration to the mineral phase of natural bone. Research studies report that addition of nano-carbon materials in HAp improves the morphology, structural and chemical properties. It also enhances the bioactivity of HAp to make it as suitable for bone engineering, drug and gene delivery applications. We have modified the surface of the synthesized HAp by incorporating nano-carbon through DC low-temperature plasma-based technique. This was achieved by varying the plasma processing parameters such as voltage, gas flow rate and processing time. The structural, morphological, chemical state, functional group and biological studies for the as-prepared and plasma processed samples were carried out using X-Ray Diffraction (XRD), Raman spectroscopy, Field Emission Scanning Electron Microscope (FESEM), High Resolution-Transmission Electron Microscope (HR-TEM), X-ray Photoelectron Spectroscopy (XPS), Fourier Transform infra-Red spectroscopy (FTIR) and Simulated Body Fluid (SBF) test, cytotoxicity analysis respectively. HR-TEM and FESEM images shows the hexagonal shape and the carbon present in the core shell of HAp. In SBF test, FESEM results confirming the formation of smooth apatite particles over the nano-carbon HAp surface