Roosen Guido F, Westgate Gillian E, Philpott Mike, Berretty Paul J M, Nuijs Tom A M, Bjerring Peter
Philips Electronics Nederland, 1077 XV Amsterdam, The Netherlands.
Lasers Surg Med. 2008 Oct;40(8):520-8. doi: 10.1002/lsm.20679.
We have recently shown that repeated low fluence photoepilation (LFP) with intense pulsed light (IPL) leads to effective hair removal, which is fully reversible. Contrary to permanent hair removal treatments, LFP does not induce severe damage to the hair follicle. The purpose of the current study is to investigate the impact of LFP on the structure and the physiology of the hair follicle.
STUDY DESIGN/MATERIALS AND METHODS: Single pulses of IPL with a fluence of 9 J/cm(2) and duration of 15 milliseconds were applied to one lower leg of 12 female subjects, followed by taking a single biopsy per person, either immediately, or after 3 or 7 days. Additionally, we present a novel approach to examine the effects of LFP, in which ex vivo hairy human scalp skin was exposed to IPL pulses with the same parameters as above, followed by isolation and culturing of the hair follicles over several days. Samples were examined histologically and morphologically.
The majority of the cultured follicles that had been exposed to LFP treatment showed a marked treatment effect. The melanin containing part of the hair follicle bulb was the target and a catagen-like transformation was observed demonstrating that hair formation had ceased. The other follicles that had been exposed to LFP showed a less strong or no response. The skin biopsies also revealed that the melanin-rich region of the hair follicle bulb matrix was targeted; other parts of the follicle and the skin remained unaffected. Catagen/telogen hair follicles were visible with unusual melanin clumping, indicating this cycle phase was induced by the IPL treatment.
Low fluence photoepilation targets the pigmented matrix area of the anagen hair follicle bulb, causing a highly localized but mild trauma that interrupts the hair cycle, induces a catagen-like state and eventually leads to temporary loss of the hair.
我们最近发现，采用强脉冲光（IPL）进行多次低能量密度光脱毛（LFP）可实现有效的毛发去除，且这种效果是完全可逆的。与永久性脱毛治疗不同，LFP不会对毛囊造成严重损伤。本研究的目的是探讨LFP对毛囊结构和生理功能的影响。
研究设计/材料与方法：对12名女性受试者的一侧小腿施加能量密度为9 J/cm²、持续时间为15毫秒的单脉冲IPL，然后在每人接受治疗后立即、3天或7天后进行单次活检。此外，我们还提出了一种新的方法来研究LFP的效果，即将离体的有毛人类头皮皮肤暴露于与上述相同参数的IPL脉冲下，随后分离并培养毛囊数天。对样本进行组织学和形态学检查。
大多数接受LFP治疗的培养毛囊显示出明显的治疗效果。毛囊球部含黑色素的部分是靶点，观察到类似退行期的转变，表明毛发形成已经停止。其他接受LFP治疗的毛囊显示出较弱或无反应。皮肤活检还显示，毛囊球基质中富含黑色素的区域是靶点；毛囊和皮肤的其他部分未受影响。可见退行期/休止期毛囊有异常的黑色素聚集，表明该周期阶段是由IPL治疗诱导的。
低能量密度光脱毛靶向生长期毛囊球部的色素基质区域，造成高度局部但轻微的创伤，中断毛发周期，诱导类似退行期的状态，最终导致毛发暂时脱落。
