ABSTRACT
(1) Background: An element that has gained much attention in industrial and biomedical fields is Cerium (Ce). CeO2 nanoparticles have been proven to be promising regarding their different biomedical applications for the control of infection and inflammation. The aim of the present study was to investigate the biological properties and antimicrobial behavior of cerium oxide (CeO2) nanoparticles (NPs). (2) Methods: The investigation of the NPs' biocompatibility with human periodontal ligament cells (hPDLCs) was evaluated via the MTT assay. Measurement of alkaline phosphatase (ALP) levels and alizarine red staining (ARS) were used as markers in the investigation of CeO2 NPs' capacity to induce the osteogenic differentiation of hPDLCs. Induced inflammatory stress conditions were applied to hPDLCs with H2O2 to estimate the influence of CeO2 NPs on the viability of cells under these conditions, as well as to reveal any ROS scavenging properties. Total antioxidant capacity (TAC) of cell lysates with NPs was also investigated. Finally, the macro broth dilution method was the method of choice for checking the antibacterial capacity of CeO2 against the anaerobic pathogens Porphyromonas gingivalis and Prevotella intermedia. (3) Results: Cell viability assay indicated that hPDLCs increase their proliferation rate in a time-dependent manner in the presence of CeO2 NPs. ALP and ARS measurements showed that CeO2 NPs can promote the osteogenic differentiation of hPDLCs. In addition, the MTT assay and ROS determination demonstrated some interesting results concerning the viability of cells under oxidative stress conditions and, respectively, the capability of NPs to decrease free radical levels over the course of time. Antimicrobial toxicity was observed mainly against P. gingivalis. (4) Conclusions: CeO2 NPs could provide an excellent choice for use in clinical practices as they could prohibit bacterial proliferation and control inflammatory conditions.
ABSTRACT
BACKGROUND: A promising strategy to enhance bone regeneration is the use of bioactive materials doped with metallic ions with therapeutic effects and their combination with active substances and/or drugs. The aim of the present study was to investigate the osteogenic capacity of human periodontal ligament cells (hPDLCs) in culture with artemisinin (ART)-loaded Ce-doped calcium silicate nanopowders (NPs); Methods: Mesoporous silica, calcium-doped and calcium/cerium-doped silicate NPs were synthesized via a surfactant-assisted cooperative self-assembly process. Human periodontal ligament cells (hPDLCs) were isolated and tested for their osteogenic differentiation in the presence of ART-loaded and unloaded NPs through alkaline phosphatase (ALP) activity and Alizarine red S staining, while their antioxidant capacity was also evaluated; Results: ART promoted further the osteogenic differentiation of hPDLCs in the presence of Ce-doped NPs. Higher amounts of Ce in the ART-loaded NPs inversely affected the mineral deposition process by the hPDLCs. ART and Ce in the NPs have a synergistic role controlling the redox status and reducing ROS production from the hPDLCs; Conclusions: By monitoring the Ce amount and ART concentration, mesoporous NPs with optimum properties can be developed towards bone tissue regeneration demonstrating also potential application in periodontal tissue regeneration strategies.
