The antibacterial properties and mechanism of nanosilver and nanozinc incorporated mesoporous calcium-silicate nanoparticles
Background: Silver (Ag) and/or zinc (Zn) incorporated mesoporous calcium-silicate nanoparticles (MCSNs) have good physicochemical characteristics and can be advanced materials for root canal filling. This study was to analyze the antibacterial properties and mechanism of Ag/Zn-MCSNs with different percentage of Ag and Zn.
Methods: The antibacterial properties and the cytotoxicity of them were evaluated. Human root canals were inoculated with E. faecalis for 4 weeks to establish bacterial biofilm model. The E. faecalis biofilms were treated with MCSNs, Ag-MCSNs, Zn-MCSNs, Ag/Zn-MCSNs, calcium hydroxide (CH) and mineral trioxide aggregate (MTA) for 7 days. The ultrastructure and distribution of viable bacteria of the specimens were evaluated using SEM and CLSM. Human root canals were pretreated with CH, MCSNs, Ag-MCSNs, Zn-MCSNs and Ag/Zn-MCSNs, then the root canals were immersed in E. faecalis suspension for 7 days. The adhesion and colonization of E. faecalis on the root canal walls were observed using SEM and CLSM. Endocytosis of E. Faecalis treated by Ag-MCSNs and Ag/Zn-MCSNs were observed using TEM.
Results: The MCSNs containing Ag showed better antibacterial properties than MCSNs and Zn-MCSNs (P<0.05). MCSNs, Ag/Zn(1:1)-MCSNs and Ag/Zn(1:9)-MCSNs showed no obvious cytotoxicity (P>0.05), while Ag-MCSNs and Ag/Zn(9:1)-MCSNs showed cytostatic effects. Zn-MCSNs slightly promote cell proliferation (P<0.05). The MCSNs containing Ag showed antibacterial abilities against E. faecalis biofilm in different degree, and can adhere to dentin surfaces to get a continuous antibacterial effect, but MTA, MCSNs and Zn-MCSNs could not disrupt the bacterial biofilm obviously. The Ag-MCSNs and Ag/Zn-MCSNs release Ag+ and destroy the cell membranes to kill bacteria.
Conclusions: The antibacterial effects and cytotoxicity of Ag/Zn-MCSNs are related to Ag content, while Zn reduce cytotoxicity and promote cell proliferation.
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Posted 30 Dec, 2019
The antibacterial properties and mechanism of nanosilver and nanozinc incorporated mesoporous calcium-silicate nanoparticles
Posted 30 Dec, 2019
Background: Silver (Ag) and/or zinc (Zn) incorporated mesoporous calcium-silicate nanoparticles (MCSNs) have good physicochemical characteristics and can be advanced materials for root canal filling. This study was to analyze the antibacterial properties and mechanism of Ag/Zn-MCSNs with different percentage of Ag and Zn.
Methods: The antibacterial properties and the cytotoxicity of them were evaluated. Human root canals were inoculated with E. faecalis for 4 weeks to establish bacterial biofilm model. The E. faecalis biofilms were treated with MCSNs, Ag-MCSNs, Zn-MCSNs, Ag/Zn-MCSNs, calcium hydroxide (CH) and mineral trioxide aggregate (MTA) for 7 days. The ultrastructure and distribution of viable bacteria of the specimens were evaluated using SEM and CLSM. Human root canals were pretreated with CH, MCSNs, Ag-MCSNs, Zn-MCSNs and Ag/Zn-MCSNs, then the root canals were immersed in E. faecalis suspension for 7 days. The adhesion and colonization of E. faecalis on the root canal walls were observed using SEM and CLSM. Endocytosis of E. Faecalis treated by Ag-MCSNs and Ag/Zn-MCSNs were observed using TEM.
Results: The MCSNs containing Ag showed better antibacterial properties than MCSNs and Zn-MCSNs (P<0.05). MCSNs, Ag/Zn(1:1)-MCSNs and Ag/Zn(1:9)-MCSNs showed no obvious cytotoxicity (P>0.05), while Ag-MCSNs and Ag/Zn(9:1)-MCSNs showed cytostatic effects. Zn-MCSNs slightly promote cell proliferation (P<0.05). The MCSNs containing Ag showed antibacterial abilities against E. faecalis biofilm in different degree, and can adhere to dentin surfaces to get a continuous antibacterial effect, but MTA, MCSNs and Zn-MCSNs could not disrupt the bacterial biofilm obviously. The Ag-MCSNs and Ag/Zn-MCSNs release Ag+ and destroy the cell membranes to kill bacteria.
Conclusions: The antibacterial effects and cytotoxicity of Ag/Zn-MCSNs are related to Ag content, while Zn reduce cytotoxicity and promote cell proliferation.
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