Leili Beytollahi1, Maryam Pourhajibagher2, Nasim Chiniforush3, Roghayeh Ghorbanzadeh4, Reza Raoofian5, Babak Pourakbari6, Abbas Bahador7. 1. Department of Microbiology, School of Medicine, International Campus, Tehran University of Medical Sciences (IC-TUMS), Tehran, Iran. 2. Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. 3. Laser Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran. 4. Private Practice, Tehran, Iran. 5. Legal Medicine Research Center, Legal Medicine Organization, Tehran, Iran; Innovative Research Center, Islamic Azad University, Mashhad Branch, Mashhad, Iran. 6. Pediatrics Infectious Disease Research Center, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. 7. Department of Microbiology, School of Medicine, International Campus, Tehran University of Medical Sciences (IC-TUMS), Tehran, Iran; Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Laser Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran; Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran. Electronic address: abahador@sina.tums.ac.ir.
Abstract
BACKGROUND: The alternative antibacterial treatments of photodynamic therapy (PDT) and photothermal therapy (PTT) significantly affect microbiota inactivation. The aim of the present research was the assessment of the antimicrobial and anti-biofilm effects of PDT with toluidine blue O (TBO) and PTT with indocyanine green (ICG) on Streptococcus mutans as a cariogenic bacterium. MATERIALS AND METHODS: The S. mutans ATCC 35668 strain was treated with final concentrations of 0.1mg/mL TBO and 1mg/mL ICG with energy densities of 17.18 and 15.62J/cm2, respectively. Cell viability was evaluated after culturing and anti-biofilm potential was analyzed using crystal violet assay and scanning electron microscopy. RESULTS: The number of S. mutans colony forming unit (CFU)/mL was significantly lower in the groups submitted to PDT (12.5-100μg/mL TBO) and PTT (62.5-1000μg/mL) compared to the control (untreated group). 0.1mg/mL TBO-PDT and 1mg/mL ICG-PTT showed stronger inhibitory effects on biofilm formation in S. mutans than other concentration levels, with a reduction of 63.87% and 67.3%, respectively. CONCLUSION: Photo-elimination by high concentrations of TBO-PDT and ICG-PTT exhibited significantly stronger inhibitory effects on biofilm formation and cell viability in S. mutans.
BACKGROUND: The alternative antibacterial treatments of photodynamic therapy (PDT) and photothermal therapy (PTT) significantly affect microbiota inactivation. The aim of the present research was the assessment of the antimicrobial and anti-biofilm effects of PDT with toluidine blue O (TBO) and PTT with indocyanine green (ICG) on Streptococcus mutans as a cariogenic bacterium. MATERIALS AND METHODS: The S. mutans ATCC 35668 strain was treated with final concentrations of 0.1mg/mL TBO and 1mg/mL ICG with energy densities of 17.18 and 15.62J/cm2, respectively. Cell viability was evaluated after culturing and anti-biofilm potential was analyzed using crystal violet assay and scanning electron microscopy. RESULTS: The number of S. mutans colony forming unit (CFU)/mL was significantly lower in the groups submitted to PDT (12.5-100μg/mL TBO) and PTT (62.5-1000μg/mL) compared to the control (untreated group). 0.1mg/mL TBO-PDT and 1mg/mL ICG-PTT showed stronger inhibitory effects on biofilm formation in S. mutans than other concentration levels, with a reduction of 63.87% and 67.3%, respectively. CONCLUSION: Photo-elimination by high concentrations of TBO-PDT and ICG-PTT exhibited significantly stronger inhibitory effects on biofilm formation and cell viability in S. mutans.
Authors: Manlin Qi; Minghan Chi; Xiaolin Sun; Xianju Xie; Michael D Weir; Thomas W Oates; Yanmin Zhou; Lin Wang; Yuxing Bai; Hockin Hk Xu Journal: Int J Nanomedicine Date: 2019-08-28