Effects of Semiconductor Laser Irradiation on Cultured Human Keratinocytes

Abstract

We studied the influence of semiconductor laser irradiation on the cultured human epidermal keratinocytes and measured cell viability and the concentration of interleukin-1α (IL-1α) in the medium of irradiated cell cultures. We found that the number of viable cells in the cultures was significantly increased by giving semiconductor laser irradiation for 15s (115.0±0.5%), 20s (112.0±1.0%) compared with the number in the nonirradiated cultures (p<0.01). The production of IL-1α by cultured cells was increased by the laser irradiation for 20s (35.8±5.5pg/ml) compared with the control (27.0±5.6pg/ml) after a 12-h incubation period (p<0.01). These results imply that low-power laser irradiation has significant biological effects on human keratinocytes.