Zhang Wei Feng, Wu Hao
College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, P. R. China, Shenzhen, China.
Lasers Med Sci. 2025 Sep 19;40(1):367. doi: 10.1007/s10103-025-04616-3.
Alopecia is a complex condition with profound social and psychological implications, creating an urgent need for safe and effective therapeutic interventions. This review introduces a novel "Wavelength-Penetration Depth-Targeting Mechanism" model to clarify the multi-level regulatory effects of full-spectrum phototherapy (spanning from ultraviolet to mid-infrared wavelengths) on hair follicle regeneration. Unlike traditional treatments such as drugs and surgery, phototherapy provides non-invasive, wavelength-specific modulation of key pathways. Specifically, UVB/UVA selectively induce apoptosis of T cells, thereby restoring immune privilege in alopecia areata (AA). Red light activates mitochondrial cytochrome c oxidase, promoting dermal papilla cell proliferation and inhibiting the progression of androgenetic alopecia (AGA) and fibrosis in scarring alopecia. Short-wavelength near-infrared light enhances hair follicle angiogenesis and metabolic activity by penetrating deep tissues. Long-wavelength near-infrared and mid-infrared light can induce minimally invasive wound healing responses. Despite progress in clinical applications across different spectral bands, several challenges remain unresolved, including narrow therapeutic windows, variable patient responses, and limited tissue penetration. These factors collectively represent bottlenecks for the advancement of full-spectrum phototherapy. Future research directions encompass artificial intelligence-driven parameter optimization (e.g., dual-network deep learning for real-time hair follicle monitoring), collaborative strategies (e.g., dual-wavelength synergy and the use of optical clearing agents to enhance light transmission efficiency), and the integration of multi-dimensional efficacy evaluation. This review elucidates the significance and future development potential of phototherapy as a precise and non-invasive treatment modality, while also delineating feasible pathways for transitioning from mechanistic insights to clinical translation.
脱发是一种复杂的病症，具有深远的社会和心理影响，因此迫切需要安全有效的治疗干预措施。本综述引入了一种新颖的“波长-穿透深度-靶向机制”模型，以阐明全光谱光疗（涵盖从紫外线到中红外波长）对毛囊再生的多层次调节作用。与药物和手术等传统治疗方法不同，光疗提供了对关键途径的非侵入性、波长特异性调节。具体而言，UVB/UVA选择性诱导T细胞凋亡，从而恢复斑秃（AA）中的免疫特权。红光激活线粒体细胞色素c氧化酶，促进真皮乳头细胞增殖，并抑制雄激素性脱发（AGA）的进展以及瘢痕性脱发中的纤维化。短波长近红外光通过穿透深层组织增强毛囊血管生成和代谢活性。长波长近红外和中红外光可诱导微创伤口愈合反应。尽管不同光谱带的临床应用取得了进展，但仍有几个挑战尚未解决，包括治疗窗口狭窄、患者反应可变以及组织穿透有限。这些因素共同构成了全光谱光疗发展的瓶颈。未来的研究方向包括人工智能驱动的参数优化（例如用于实时毛囊监测的双网络深度学习）、协同策略（例如双波长协同作用以及使用光学透明剂提高光传输效率）以及多维度疗效评估的整合。本综述阐明了光疗作为一种精确且非侵入性治疗方式的意义和未来发展潜力，同时也描绘了从机制洞察到临床转化的可行途径。
