BACKGROUND AND OBJECTIVE: Some oral bacteria are susceptible to killing by red light after their sensitization with toluidine blue O (TBO). The photochemotherapy of periodontal disease in vivo would require a therapeutic window where bacteria could be killed without adjacent normal tissue damage. STUDY DESIGN/ MATERIALS AND METHODS: The laser-induced effects of TBO on normal human gingival keratinocytes and fibroblasts have been studied in vitro. For the assessment of viability, the CellTiter 96TM AQueous Non-Radioactive Cell Proliferation Assay was used. RESULTS: TBO was cytotoxic at low concentrations (5.0 micrograms/ml). Sensitization of keratinocytes and fibroblasts with 2 and 5.0 micrograms/ml TBO, respectively, for 5 min and exposure to light from a 7.3 mW Helium/Neon (HeNe) laser for up to 2 min (0.876J) did not reduce cell viability. However, killing of Streptococcus sanguis was achieved following exposure to HeNe light for 75 sec (0.547J) in the presence of TBO at a concentration of 2.5 micrograms/ml. CONCLUSION: The development of a system for the lethal photosensitization of bacteria responsible for periodontal disease may be possible.
BACKGROUND AND OBJECTIVE: Some oral bacteria are susceptible to killing by red light after their sensitization with toluidine blue O (TBO). The photochemotherapy of periodontal disease in vivo would require a therapeutic window where bacteria could be killed without adjacent normal tissue damage. STUDY DESIGN/ MATERIALS AND METHODS: The laser-induced effects of TBO on normal human gingival keratinocytes and fibroblasts have been studied in vitro. For the assessment of viability, the CellTiter 96TM AQueous Non-Radioactive Cell Proliferation Assay was used. RESULTS:TBO was cytotoxic at low concentrations (5.0 micrograms/ml). Sensitization of keratinocytes and fibroblasts with 2 and 5.0 micrograms/ml TBO, respectively, for 5 min and exposure to light from a 7.3 mW Helium/Neon (HeNe) laser for up to 2 min (0.876J) did not reduce cell viability. However, killing of Streptococcus sanguis was achieved following exposure to HeNe light for 75 sec (0.547J) in the presence of TBO at a concentration of 2.5 micrograms/ml. CONCLUSION: The development of a system for the lethal photosensitization of bacteria responsible for periodontal disease may be possible.
Authors: Merrill A Biel; Chet Sievert; Marina Usacheva; Matthew Teichert; Jim Balcom Journal: Int Forum Allergy Rhinol Date: 2011-08-18 Impact factor: 3.858
Authors: George P Tegos; Tatiana N Demidova; Dennisse Arcila-Lopez; Haeryeon Lee; Tim Wharton; Hariprasad Gali; Michael R Hamblin Journal: Chem Biol Date: 2005-10
Authors: Yan Xu; Mark J Young; Ricardo A Battaglino; Leslie R Morse; Carla Raquel Fontana; Tom C Pagonis; Ralph Kent; Nikolaos S Soukos Journal: J Endod Date: 2009-09-20 Impact factor: 4.171