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Photodynamic effects of toluidine blue on human oral keratinocytes and fibroblasts and Streptococcus sanguis evaluated in vitro
Author(s) -
Soukos Nikolaos S.,
Wilson Michael,
Burns Tracy,
Speight Paul M.
Publication year - 1996
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/(sici)1096-9101(1996)18:3<253::aid-lsm6>3.0.co;2-r
Subject(s) - viability assay , toluidine , in vivo , fibroblast , in vitro , chemistry , microbiology and biotechnology , bacteria , sensitization , biology , immunology , biochemistry , genetics
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 96™ AQueous Non‐Radioactive Cell Proliferation Assay was used. Results TBO was cytotoxic at low concentrations (5.0 μg/ml). Sensitization of keratinocytes and fibroblasts with 2 and 5.0 μg/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 μg/ml. Conclusion The development of a system for the lethal photosensitization of bacteria responsible for periodontal disease may be possible. © 1996 Wiley‐Liss, Inc.