Development and application of LED arrays for use in phototherapy research.
Lasers/LEDs demonstrate therapeutic effects for a range of biomedical applications. However, a consensus on effective light irradiation parameters and efficient and reliable measurement techniques remain limited. The objective here is to develop, characterise and demonstrate the application of LED arrays in order to progress and improve the effectiveness and accuracy of in vitro photobiomodulation studies. 96-well plate format LED arrays (400-850 nm) were developed and characterised to accurately assess irradiance delivery to cell cultures. Human dental pulp cells (DPCs) were irradiated (3.5-142 mW/cm2: 15-120 s) and the biological responses were assessed using MTT assays. Array calibration was confirmed using a range of optical and analytical techniques. Multivariate analysis of variance revealed biological responses were dependent on wavelength, exposure time and the post-exposure assay time (P < 0.05). Increased MTT asbsorbance was measured 24 h post-irradiation for 30 s exposures of 3.5 mW/cm2at 470, 527, 631, 655, 680, 777, 798 and 826 nm with distinct peaks at 631 nm and 798 nm (P < 0.05). Similar wavelengths were also effective at higher irradiances (48-142 mW/cm2). LED arrays and high throughput assays provide a robust and reliable platform to rapidly identify irradiation parameters which is both time- and cost-effective. These arrrays are applicable in photobiomodulation, photodynamic therapy and other photobiomedical research.
School of Dentistry, College of Medical and Dental Sciences, Institute of Clinical Sciences, University of Birmingham, 5 Mill Pool Way, Edgbaston, Birmingham, B5 7EG, UK.
Mohammed A
MA
Hadis
School of Dentistry, College of Medical and Dental Sciences, Institute of Clinical Sciences, University of Birmingham, 5 Mill Pool Way, Edgbaston, Birmingham, B5 7EG, UK.
Paul R
PR
Cooper
School of Dentistry, College of Medical and Dental Sciences, Institute of Clinical Sciences, University of Birmingham, 5 Mill Pool Way, Edgbaston, Birmingham, B5 7EG, UK.
Michael R
MR
Milward
School of Dentistry, College of Medical and Dental Sciences, Institute of Clinical Sciences, University of Birmingham, 5 Mill Pool Way, Edgbaston, Birmingham, B5 7EG, UK.
Patricia C
PC
Gorecki
School of Electronic, Electrical and Computer Engineering, University of Birmingham, Birmingham, B15 2TT, UK.
Edward
E
Tarte
School of Electronic, Electrical and Computer Engineering, University of Birmingham, Birmingham, B15 2TT, UK.
James
J
Churm
School of Dentistry, College of Medical and Dental Sciences, Institute of Clinical Sciences, University of Birmingham, 5 Mill Pool Way, Edgbaston, Birmingham, B5 7EG, UK.
William M
WM
Palin
D055615:Electrical Equipment and Supplies; D010789:Phototherapy / Q000295:instrumentation*
dentine-pulp complex; low level light therapy; photobiomodulation; photodisinfection; phototherapy; stem cells