Titanium dioxide nanoparticles impart protection from ultraviolet irradiation to fermenting yeast cells

Denture Base Resin Coated with Titanium Dioxide (TiO2): A Systematic Review

Background

The main objective of this systematic review was to evaluate the effect of coating with titanium dioxide nanoparticles (TiO2 nanoparticle) on the surface condition of removable acrylic resin prosthetic base materials.

Methods

Our review is registered in the PROSPERO database under the identification code CRD42023397170. Electronic database searches of PubMed, Scopus and Science Direct including studies from January 2009 to January 2023 were conducted and supplemented with manual searches. Research questions were generated in accordance with the PICO strategy. The modified Consolidated Standards of Reporting Trials (CONSORT) checklist was used to evaluate the quality of the selected studies.

Results

Since the included studies were variable in design, a meta-analysis was not performed. The electronic searches retrieved 29 references that met the eligibility criteria, among which 5 studies matched the inclusion criteria for this review. Significant differences were detected between the TiO2 NP-coated and uncoated groups. The available data indicate that TiO2 NP coating elicits antimicrobial activity and improves the wear resistance of polymethylmethacrylate (PMMA) surfaces. Moreover, the nanoparticles provide high levels of glossiness and decelerate the process of color change of heat-cured acrylic resin, thus increasing the lifespan of dentures.

Conclusion

The collective results clearly indicate that TiO2 nanoparticle coating induces alterations in the surface properties of pure PMMA, enhancing the mechanical, physical and biological characteristics of the denture base material. Further studies are essential to identify the optimal thickness of coating and concentrations of nanoparticles for clinical applications.

Surface Coating of Titanium Dioxide Nanoparticles with a Polymerizable Chelating Agent and Its Physicochemical Property

Surface modification of inorganic nanoparticles is critical for the quality and performance of pigments, cosmetics, and composite materials. We covered the titanium dioxide nanoparticles' surface with 2-(acetoacetoxy) ethyl methacrylate, a polymerizable chelating agent. Through the in situ polymerization procedure, this molecule's β-ketoester moiety quickly coordinated with the metal atoms on titanium dioxide nanoparticles, and its methacrylate group formed homogeneous coating layers. This coating layer significantly reduced the photocatalytic activity of titanium dioxide nanoparticles and prevented their aggregation. This nanoparticle dispersion showed low viscosity up to the solid content of 60% (w/w) in the liquid dispersant. As a result, it increased the UV screening performance and dispersion stability. Additionally, this coating layer widened the absorption spectrum of titanium dioxide and could change the color of nanoparticles from pale yellow to brown. It can also be helpful for cosmetic applications.

Metal-Based Nanoparticles: Antibacterial Mechanisms and Biomedical Application

The growing increase in antibiotic-resistant bacteria has led to the search for new antibacterial agents capable of overcoming the resistance problem. In recent years, nanoparticles (NPs) have been increasingly used to target bacteria as an alternative to antibiotics. The most promising nanomaterials for biomedical applications are metal and metal oxide NPs, due to their intrinsic antibacterial activity. Although NPs show interesting antibacterial properties, the mechanisms underlying their action are still poorly understood, limiting their use in clinical applications. In this review, an overview of the mechanisms underlying the antibacterial activity of metal and metal oxide NPs will be provided, relating their efficacy to: (i) bacterial strain; (ii) higher microbial organizations (biofilm); (iii) and physico-chemical properties of NPs. In addition, bacterial resistance strategies will be also discussed to better evaluate the feasibility of the different treatments adopted in the clinical safety fields. Finally, a wide analysis on recent biomedical applications of metal and metal oxide NPs with antibacterial activity will be provided.