Cytotoxicity of Modified Nonequilibrium Plasma with Chlorhexidine Digluconate on Primary Cultured Human Gingival Fibroblasts

The aim of this study was to investigate the cytotoxicity of modified nonequilibrium plasma with chlorhexidine digluconate（CHX） on human gingival fibroblasts（HGFs）, and to evaluate the biosecurity of modified nonequilibrium plasma with 2% CHX as a new method of root canal treatment. Tissue samples taken from human gingiva were primarily cultured and passaged. Cells from passages 3–7 were used. HGFs were treated by modified nonequilibrium plasma with 2% CHX for 0 min（control group）, 30 s, 1 min, 1.5 min, 3 min, 5 min, and 10 min, respectively, and then they were incubated for 0, 24, and 48 h. After that, cell counting kit-8（CCK-8） assay was applied to analyze the cytotoxicity of modified nonequilibrium plasma with 2% CHX on HGFs. There was no significant difference between the 0 h group treated with the modified nonequilibrium plasma for 1 min and the control group（P〉0.05）. However, there were significant differences between all the other treated groups and the control group（P〈0.05）. When treated for 1.5 min or shorter, the cell viability was obviously increased; while treated for 3 min or longer, it was obviously reduced. Moreover, when successively cultured for 0, 24, and 48 h, cell viability was decreased at first and then increased in the 3-min-treated and 5-min-treated groups. The modified nonequilibrium plasma with 2% CHX was of no influence on cell viability in 1.5 min treatment, and it could be safely used on root canal treatment.

Co-implantation of magnesium and zinc ions into titanium regulates the behaviors of human gingival fibroblasts

Soft tissue sealing around implants acts as a barrier between the alveolar bone and oral environment,protecting implants from the invasion of bacteria or external stimuli.In this work,magnesium(Mg)and zinc(Zn)are introduced into titanium by plasma immersed ion implantation technology,and their effects on the behaviors of human gingival fibroblasts(HGFs)as well as the underlying mechanisms are investigated.Surface characterization confirms Mg and Zn exist on the surface in metallic and oxidized states.Contact angle test suggests that surface wettability of titanium changes after ion implantation and thus influences protein adsorption of surfaces.In vitro studies disclose that HGFs on Mg ion-implanted samples exhibit better adhesion and migration while cells on Zn ion-implanted samples have higher proliferation rate and amounts.The results of immunofluorescence staining and real-time reverse-transcriptase polymerase chain reaction(RT-PCR)suggest that Mg mainly regulates the motility and adhesion of HGFs through activating the MAPK signal pathway whereas Zn influences HGFs proliferation by triggering the TGF-βsignal pathway.The synergistic effect of Mg and Zn ions ensure that HGFs cultured on co-implanted samples possessed both high proliferation rate and motility,which are critical to soft tissue sealing of implants.

Doping Gd^(3+)Ion in PDA-PHBV Coating on Ti6Al4V Alloy for Enhancing Corrosion Resistance and Proliferation of Human Gingival Fibroblasts and Human Umbilical Vein Endothelial Cells

In this study,we fabricated poly(3-hydroxybutyrate-3-hydroxyvalerate)(PHBV)coatings doped with Gd^(3+)(1,5,and 10×10^(−4) mol/L)on Ti6Al4V alloy for the first time to promote soft tissue sealing around dental implants.The corrosion resistance of Gd^(3+)-modified PHBV-coated Ti6Al4V was studied by electrochemical and immersion tests,respectively,whereas CCK-8 and RT-PCR evaluated the biocompatibility to human gingival fibroblasts(HGFs)and human umbilical vein endothelial cells(HUVECs).It was found that the Gd^(3+)-modified PHBV coating could enhance the corrosion resistance of Ti6Al4V.In vitro cell tests showed that PHBV coatings with and without Gd^(3+) addition could promote adhesion and proliferation of HGFs and HUVECs,showing a Gd^(3+) content-dependent manner.Moreover,it was found that the PDA-PHBV@1Gd showed the best proliferation to HGFs by up-regulating gene expressions of VINCULIN,ITGB1,and ITGA3,whereas the best response to HUVECs with the highest gene expression of eNOS and HIF-1αgenes was found in the PDA-PHBV@5Gd-coated group.

Enhancing cell adhesive and antibacterial activities of glass-fibre-reinforced polyetherketoneketone through Mg and Ag PIII

Glass-fibre-reinforced polyetherketoneketone(PEKK-GF)shows great potential for application as a dental implant restoration material;however,its surface bioinertness and poor antibacterial properties limit its integration with peri-implant soft tissue,which is critical in the long-term success of implant restoration.Herein,functional magnesium(Mg)and silver(Ag)ions were introduced into PEKK-GF by plasma immersion ion implantation(PIII).Surface characterization confirmed that the surface morphology of PEKK-GF was not visibly affected by PIII treatment.Further tests revealed that PIII changed the wettability and electrochemical environment of the PEKK-GF surface and enabled the release of Mg^(2+)and Ag^(+)modulated by Giavanni effect.In vitro experiments showed that Mg/Ag PIII-treated PEKK-GF promoted the proliferation and adhesion of human gingival fibroblasts and upregulated the expression of adhesion-related genes and proteins.In addition,the treated samples inhibited the metabolic viability and adhesion of Streptococcus mutans and Porphyromonas gingivalis on their surfaces,distorting bacterial morphology.Mg/Ag PIII surface treatment improved the soft tissue integration and antibacterial activities of PEKK-GF,which will further support and broaden its adoption in dentistry.