Development and application of LED arrays for use in phototherapy research. Issue 11 (6th February 2017)

• Record Type: Journal Article
• Authors: Hadis, Mohammed A.; Cooper, Paul R.; Milward, Michael R.; Gorecki, Patricia. C.; Tarte, Edward; Churm, James; Palin, William M.
• Is Part Of: Journal of biophotonics. Volume 10:Issue 11(2017)
• Page Start: 1514
• Page End: 1525
• Publication Date: 2017-02-06
• Subjects: photobiomodulation -- phototherapy -- photodisinfection -- dentine‐pulp complex -- stem cells -- low level light therapy; Photonics -- Periodicals; Optical materials -- Periodicals; Optics -- Periodicals; Medical instruments and apparatus -- Periodicals; 621.3605
• DOI: 10.1002/jbio.201600273
• Languages: English
• ISSNs: 1864-063X

Abstract

Abstract : 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/cm 2 : 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/cm 2 at 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/cm 2 ). 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. Abstract : LED micro arrays and a rapid assay method that can be used to identify irradiation parameters in low level light therapy (LLLT), photodynamic therapy and photodissinfection are developed and its application is demonstrated in vitro using dental pulp cells. The method provides a robust and reliable platform for hight‐hroughput analysis of biological effects which has time‐saving and is cost‐effective for use in research laboratories.