1416 Effects of red-wavelengths OLED and its in vitro differential cell effects

      Photobiomodulation(PBM) is a safe and non-invasive method that can provide various clinical effects. At present, conventional PBM devices using point light sources such as Light-Emitting Diode and laser have various problems such as low flexibility, relatively heavy weight, and non-uniform effects. In this study, we present a novel wearable PBM patch using a flexible red-wavelengths Organic Light-Emitting Diode (OLED) light source which can be attached to the human body. It will provide practical performance (> 10mW/cm2) even at low voltage (< 10V). Compared to LED platform, OLED platform can provide relatively pure wavelengths. Although there are numerous possible applications, a wound will be a good indication for flexible PBM therapy. The effects of OLED PBM therapy was investigated using scratch-wound healing assay model of cultured normal human fibroblasts. Our results showed that red-wavelengths OLED (630, 650, 670, 690 nm) may have excellent in vitro wound healing effects because they effectively stimulate fibroblast proliferation and enhance fibroblast migration. Interestingly, there are relatively large differences according to the wavelength used. Among the wavelengths tested, 650nm and 670 nm induced rapid proliferation of fibroblasts, indicating these wavelengths can induce quick dermal repair during the wound healing process. Wavelengths of 630 and 650 nm induced more migration at low energy levels while wavelengths of 670 nm and 690nm induced more migration at high energy levels. These findings indicate that different wavelengths may show different biologic responses according to the energy level. In this study, we could conclude that the wearable OLED system can be used in various therapeutic applications in the future, including medical and cosmetic procedures.