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Published on: September 19, 2019
Biocompatibility and photoinactivation evaluation of zinc hydroxide chloride nanosheets against Streptococcus mutans
Shima Afrasiabi1, Fatemeh Saghatchi2, Ahmad Reza Dehpour3,4
1Laser Research Center of Dentistry, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
Background:
Considering the efficacy of antimicrobial photodynamic therapy (PDT) in inactivating bacteria, this study reports that zinc hydroxide chloride nanosheets (ZHC-NSs) are useful for this purpose.
Materials & Methods:
The characterization of ZHC-NSs was performed using microscopic and spectroscopic techniques. The irritation test, acute toxicity test, and genotoxicity test of ZHC-NSs were evaluated and their effects on human pulp fibroblast cells (HPFC) viability, intracellular reactive oxygen species (ROS) levels, and antibacterial activity of ZHC-NSs (1-8 mg ml-1) alone or in light conditions were investigated.
Results:
The ZHC-NSs structure showed a crystalline form and their sheets' thickness had an average size of 129.6 ± 19.50 nm. ZHC-NSs did not severely damage internal organs and were not genotoxic. The cytotoxic effect of ZHC-NSs on HPFC was concentration-dependent so that ZHC-NSs at higher concentrations (4 and 8 mg ml-1) killed half of the HPFC cells. When ZHC-NSs were used in combination with a 980 nm diode laser, namely ZHC-NS©, ROS production increased and led to enhanced antibacterial activity against Streptococcus mutans in planktonic and biofilm form. A statistically significant difference was found between ZHC-NSs without laser irradiation and photoexcited ZHC-NSs.
Conclusion:
ZHC-NSs© with the potential ability to produce ROS could be effective in complementary treatment against S. mutans.
