Therapeutic application of light emitting diode: Photo-oncomic approach.

As a new light source, light emitting diode (LED) with high brightness and lower cost has been rapidly developed in medical application and light therapy. LED phototherapy can activate target cells with appropriate power and adequate energy density. This review provides general information on therapeutic applications of blue, green, yellow, red, and infrared LED in medical treatments for various physical abnormalities and on bio-imaging. The bio-imaging system is improved by decreasing the number of microscopes apparatuses including neutral-density filter, excitation filters and mechanical shutters. The numbers of excitation photons are increased and the fluorescent excitation efficiency is improved at cellular level. In the target tissue, the therapeutic effect of LEDs is dependent on incident photons irrespective of the system used to generate these photons. Photomodulated light from LED device is delivered in pulsed mode with specific pulse sequences and time. Too low or too high dose of energy may be ineffective at all. Clinical applications of LED light depending on different wavelengths are summarized. The author's photo-oncomic experiments using a specific blue light emitting diode were introduced, showing that blue LED possessed anti-proliferative and anti-metastatic abilities in cancer cells and mice. As a promising light source, photo-oncomic approach of blue LED could be applied to treat cancers and inflammatory diseases.