Impact of near-infrared radiation in dermatology

• 作者: Yohei Tanaka
• 来源期刊: 世界皮肤病学杂志
• 学科: 医学
• 关键词: NEAR-INFRARED NON-THERMAL BIOLOGICAL effects PHOTOAGING DAMAGE Protection Stem cell Cancer
• 年，卷（期）: 2012,（3）
• 页码范围: 30-37
• 页数: 8页
• 分类号: R

摘要

Sunlight that reaches the human skin contains solar energy composed of 6.8%ultraviolet(UV),38.9%visible light and 54.3%infrared radiation.In addition to natural near-infrared(NIR),human skin is increasingly exposed to artificial NIR from medical devices and electrical appliances.Thus,we are exposed to tremendous amounts of NIR.Many studies have proven the effects of UV exposure on human skin and skin cancers but have not investigated well the effects of NIR exposure.Furthermore,many of the previous NIR studies have used NIR resources without a water filter or a contact cooling.With these resources,a substantial amount of NIR energy is absorbed in the superficial layers and only limited NIR energy can be delivered to deeper tissues.Thus,they could not sufficiently evaluate the effects of incident solar NIR.In order to simulate solar NIR that reaches the skin,a water filter is essential because solar NIR is filtered by atmospheric water.In reality,NIR increases the surface temperature and induces thermal effects so a contact cooling is needed to pursue the properties of NIR.I clarify that NIR can penetrate the skin and non-thermally affect the subcutaneous tissues,including muscle and bone marrow,using a NIR resource with a water filter and a cooling system.I would like to emphasize the biological effects of NIR which have both merits and demerits.Appropriate NIR irradiation induces dermal heating thermally and non-thermally induces collagen and elastin stimulation,which results in skin tightening.NIR also induces non-thermal DNA damage of mitotic cells,which may have the potential application for treating cancer.However,as continuous NIR exposure may induce photoaging and potentially photocarcinogenesis,we should consider the effect of,not only UV,but also NIR and the necessity for protection against solar NIR.Here,this paper introduces the new aspects of the biological effects of NIR radiation.