Development of novel NIR laser therapy: the effect of selective heating of collagen on fibroblasts

Abstract

We investigated the photothermal effect of near-infrared (NIR) pulsed laser irradiation on collagen synthesis in fibroblasts in vitro. Pain with thermal damage caused by laser heating of the water is a problem in the conventional laser skin therapy. We suggest heating collagen fibril selectively by applying selective photothermolysis and using NIR laser at the wavelength where the absorption coefficient of the collagen is greater than that of the water. This study aims to determine laser irradiation conditions for novel laser therapy, therefore 1480 and 1550 nm pulsed laser was irradiated to cultured fibroblasts with various radiant exposure and pulse duration. We evaluated the amount of collagen type I and HSP47 per living cell 24 and 48h after laser irradiation.