Improved cosmeceutical phototherapy using microneedle

Skin rejuvenation is the most popular topic in cosmetic industry. Recently, skin phototherapy is spotlighted among a lot of skin therapies by its advantageous effects and ease of use. Phototherapy has been widely used for cosmeceutical purposes such as anti-aging or anti-bacterial effects. By the optical properties of light, however, the visible lights cannot reach deep inside the skin layer by reflection and scattering at the outermost boundary of the skin, the stratum corneum and epidermis. This paper describes new method to improve the skin phototherapy using microneedles. We used microneedle as the light transporter like optic fiber to transport light inside the skin by total internal reflection. The total internal reflection inside microneedles was geometrically analyzed and was measured microscopically. The light transmittance with or without a microneedle array was measured using an optical microscope system. Three different ranges of lights (red, green, blue) were exposed on the backside of the microneedle and the light pass through the microneedles. As the results, using microneedles, light transmissivity was dramatically improved even the shorter wavelength of the light (Blue light). Collaboration of phototherapy and microneedle will be a powerful cosmetic and medical tool for skin therapy.