IADR Abstract Archives
LED irradiation at 660nm stimulates human oral epithelial cell growth responses
Objectives: The aim of this study was to determine beneficial biological responses in human oral epithelial cells irradiated by light-emitting diodes (LEDs). Mitochondrial metabolic activity and cell proliferation were evaluated in the response to LED irradiation utilising a range of wavelengths and doses (radiant exposures).
Methods: A bespoke LED array consisting of 42 LEDs (24mW/cm2) with a range of wavelengths between 400-830nm (7 wavelengths, n=6) was used for light irradiation. Initial light characterisation determined the spectral irradiance and wavelength for each LED using a calibrated fibre-based spectrometer (USB4000, Ocean Optics). Human gingival epithelial cells (H400) were seeded (3000 cells/well) in DMEM (supplemented with 5% FCS) in black-walled, transparent based 96-well plates and incubated at 37°C in 5% CO2. Cultures were exposed to the bespoke LED array with doses between 0 and 11.6 J/cm2 at 24h post-seeding. Cell number, mitochondrial metabolic activity (MTT assay) and DNA synthesis (BrdU assay) were determined 48h post-irradiation. Statistical analyses were performed using ANOVA and Tukey post-hoc tests (p<0.05).
Results: Following LED irradiation at a wavelength of 660nm mitochondrial metabolic activity, cell proliferation and DNA synthesis were all significantly increased (p<0.05) and indicated that a radiant exposure of 11.6J/cm2 (480s) gave the most effective biological response.
Conclusions: This study indicates that LED exposure at a wavelength of 660nm may provide a potential therapeutic approach for enhancing healing of the gingival epithelium in periodontal disease. Further optimisation of the efficacy of irradiation parameters should be performed to identify the most appropriate conditions for therapeutic application.
Methods: A bespoke LED array consisting of 42 LEDs (24mW/cm2) with a range of wavelengths between 400-830nm (7 wavelengths, n=6) was used for light irradiation. Initial light characterisation determined the spectral irradiance and wavelength for each LED using a calibrated fibre-based spectrometer (USB4000, Ocean Optics). Human gingival epithelial cells (H400) were seeded (3000 cells/well) in DMEM (supplemented with 5% FCS) in black-walled, transparent based 96-well plates and incubated at 37°C in 5% CO2. Cultures were exposed to the bespoke LED array with doses between 0 and 11.6 J/cm2 at 24h post-seeding. Cell number, mitochondrial metabolic activity (MTT assay) and DNA synthesis (BrdU assay) were determined 48h post-irradiation. Statistical analyses were performed using ANOVA and Tukey post-hoc tests (p<0.05).
Results: Following LED irradiation at a wavelength of 660nm mitochondrial metabolic activity, cell proliferation and DNA synthesis were all significantly increased (p<0.05) and indicated that a radiant exposure of 11.6J/cm2 (480s) gave the most effective biological response.
Conclusions: This study indicates that LED exposure at a wavelength of 660nm may provide a potential therapeutic approach for enhancing healing of the gingival epithelium in periodontal disease. Further optimisation of the efficacy of irradiation parameters should be performed to identify the most appropriate conditions for therapeutic application.