Short Wavelength UV Sources for Treatment of Psoriasis

描述(申请人提供)：项目摘要/摘要：研究工作将集中在制造发射范围为305纳米至315纳米的紫外光发光二极管(LED)，用于牛皮癣的光疗。这一波长范围内紫外线光源的成功生产将使人们能够研究治疗牛皮癣以及可能的其他皮肤病的新的光疗方案，这些皮肤病包括寻常痤疮、特应性皮炎、白癜风、瘙痒、扁平苔藓、玫瑰糠疹和早期皮肤T细胞淋巴瘤。为了设计和实施有效的光治疗，必须在清除牛皮癣的作用光谱内提供特定波长和功率密度的紫外线源。短于295 nm的波长在较高剂量下会产生光毒性，对银屑病没有积极作用。在波长超过315 nm的情况下，与皮肤组织的反应大大减少，在UVA区域暴露需要的剂量大约是UVB的1000倍，而在小暴露部位观察到的成功非常有限。这表明，特定波长的单色辐射可能比暴露在宽带光源下更具治疗作用。紫外线范围内的所有光疗都受到邻近受影响区域的正常非受累皮肤的破坏性辐射照射的限制，需要严格控制波长、剂量、分布和投放。紫外线光源是光疗治疗牛皮癣等特定皮肤病的核心技术。今天，这些光源主要是宽带高压水银灯、水银氙气、水银氦气和水银光源或准分子激光器。在实践中，这意味着光疗方法必须适应可用的光源波长，而不是将光源优化到感兴趣的特定波长(S)。这项提议集中在开发基于氮化铝镓(AlGaN)合金的LED，这种合金可以覆盖很大一部分有用的UV光谱。这些半导体器件紧凑(大约一粒米大小)，寿命长，稳定性好，需要简单的驱动电子设备。每个器件具有窄的发射光谱，可在制造期间通过调整器件的有源层的成分和结构来调节该发射光谱。因此，UV LED的组合可以在它们覆盖的波长范围内提供特定的、可选择的光谱(通过电子控制)。宽带UVB、窄带UVB、宽带UVA、光化学疗法(PUVA)和光动力疗法(PDT)都是需要紫外线光源的应用。项目简介：基于氮化物的紫外线LED在305 nm至315 nm(UVB)范围内发射，可成功地用于某些疾病和皮肤病的光疗。这一波长范围已被证明对治疗牛皮癣有效。现有的牛皮癣光疗法既昂贵又耗时，而且可能会干扰就业或学校时间表。需要一种基于305 nm至315 nm LED的廉价紧凑型UV设备可以开给患者用于家庭治疗牛皮癣。

DESCRIPTION (provided by applicant): Project Summary/Abstract: Research efforts will focus on fabrication of ultraviolet (UV) light emitting diodes (LEDs) in the emission range of 305 nm to 315 nm for phototherapy of psoriasis. Successful production of UV sources in this wavelength range will enable research for new phototherapy treatment programs for psoriasis and possibly other skin diseases including acne vularis, atopic dermatitis, vitiligo, pruritus, lichen planus, pityriasis rosea and early cutaneous T-cell lymphoma. To design and implement effective light treatments, UV sources at specific wavelengths and power densities have to be available within the action spectrum for clearing psoriasis. Wavelengths shorter than 295 nm produce phototoxicity at higher doses with no positive effect on the psoriasis. At wavelengths above 315 nm, reactions with the skin tissue is greatly reduced, with exposure in the UVA region requiring about 1000 times the dose compared to UVB with very limited success observed on small exposure sites. This suggests that monochromatic radiation at specific wavelengths may be more therapeutic than exposure to broadband sources. All phototherapy in the UV range is limited by injurious exposure to radiation on normal uninvolved skin adjacent to the affected areas and strict control of wavelength, doses, distribution and delivery are required. UV light sources are a core enabling technology in phototherapy for treatment of specific skin diseases such as psoriasis. Today, these light sources are primarily broadband high pressure mercury lamps, mercury xenon, mercury argon and deuterium sources or excimer lasers. In practice, this has meant that phototherapy treatment methods have had to be adapted to the available light source wavelengths rather than optimizing the light sources to specific wavelength(s) of interest. This proposal concentrates on the development of LEDs based on aluminum gallium nitride (AlGaN) alloys that can cover a large and useful portion of the UV spectrum. These semiconductor devices are compact (about the size of a grain of rice), stable over long lifetimes, and require simple drive electronics. Each device has a narrow emission spectrum that is tuned by adjusting the composition and structure of the active layers of the device during manufacture. Thus, a combination of the UV LEDs can deliver a specific, selectable spectrum (via electronic control) over the wavelength range they cover. Broadband UVB, narrow band UVB, broadband UVA, photochemotherapy (PUVA) and photodynamic therapy (PDT) are among the applications in which UV sources are required. Project Narrative: Nitride based UV LEDs emitting in the 305 nm to 315 nm (UVB) range can be successfully employed in phototherapy of certain illnesses and skin diseases. This wavelength range has proven effective in treating psoriasis. Existing psoriasis phototherapy treatments are costly and time consuming and can interfere with employment or school schedules. A need exists in which an inexpensive compact UV apparatus based on 305 nm to 315 nm LEDs can be prescribed to a patient for in-home use for the treatment of psoriasis.