Chrit L, Hadjur C, Morel S, Sockalingum G, Lebourdon G, Leroy F, Manfait M
L'Oréal Recherche, Aulanay sous Bois, France.
J Biomed Opt. 2005 Jul-Aug;10(4):44007. doi: 10.1117/1.2003747.
To evaluate the potential of a new in vivo confocal Raman microprobe, we undertake a pilot study in human skin. A fiber optic probe is operated with a 633-nm laser and trials are conducted in healthy volunteers. We examine changes in molecular composition and structure of the stratum corneum, from different volunteers, from different anatomical sites and skin layers. Main spectral variations are detected in the following regions: 800 to 900 cm(-1) (amino acids); 1200 to 1290 cm(-1) (proteins); and 1030 to 1130 cm(-1), 1300 to 1450 cm(-1), and 2800 to 2900 cm(-1) (lipids). Curve fitting of the amide 1 region performs in detail protein secondary structural variations of the amide 1 band. Protein conformation is also found to vary depending on the anatomical site and volunteer. Similar analysis of the 730- to 1170-cm(-1) spectral window reveals a different organization of lamellar lipids: gel for forearm and palm, and liquid-crystalline phase for fingertips. All these variations result from changes in the stratum corneum components such as natural moisturizing factor (NMF), lipids (namely ceramides), and water. Hierarchical clustering classification is also performed to sort out Raman data obtained from different subjects. Further improvement of the confocal probe would be to adapt a 360-deg configuration enabling access to other anatomical sites.
为评估一种新型体内共聚焦拉曼微探针的潜力，我们在人体皮肤中开展了一项初步研究。使用光纤探针与633纳米激光进行操作，并在健康志愿者身上进行试验。我们研究了来自不同志愿者、不同解剖部位和皮肤层的角质层分子组成和结构的变化。在以下区域检测到主要光谱变化：800至900厘米⁻¹（氨基酸）；1200至1290厘米⁻¹（蛋白质）；以及1030至1130厘米⁻¹、1300至1450厘米⁻¹和2800至2900厘米⁻¹（脂质）。对酰胺I区域进行曲线拟合，详细分析了酰胺I带的蛋白质二级结构变化。还发现蛋白质构象因解剖部位和志愿者而异。对730至1170厘米⁻¹光谱窗口进行类似分析，揭示了层状脂质的不同组织形式：前臂和手掌为凝胶态，指尖为液晶态。所有这些变化均源于角质层成分的改变，如天然保湿因子（NMF）、脂质（即神经酰胺）和水。还进行了层次聚类分类，以整理从不同受试者获得的拉曼数据。共聚焦探针的进一步改进将是采用360度配置，以便能够检测其他解剖部位。
