Exvivo ESR Spin Rrobe Investigation of Stratum Corneum Lipids

电子自旋共振(ESR)是研究角质层(SC)脂质有序性的有用手段。由ESR谱得到的有序参数可以作为评价SC脂流动性的良好指标。然而，目前还没有建立评价体外SC脂类的方法。我们研究了ESR方法的细节。使用氰基丙烯酸酯树脂的玻璃板剥离SC脂类。使用单链脂肪族自旋探针5-羟基硬脂酸(5-DSA)。SC样品在0.001%5-DSA的0.1%乙醇水溶液中37℃孵育60分钟。孵化后，将装有孵化的Sc样品的ESR玻璃支架安装在ESR腔中。新设计的ESR玻璃支架改进了样品制备和ESR测量。采用慢滚转模拟方法对Sc样品的ESR波谱进行了全面分析。通过模拟得到的有序参数显示了SC脂的深度依赖关系，作为SC中深度的函数。因此，我们建立了SC脂的样品制备和精确的ESR测量和光谱分析。此外，我们还首次发现了体外SC脂质有序性的深度依赖性。

Electron spin resonance (ESR) is useful for studying stratum corneum (SC)lipid ordering. Order parameter obtained from ESR spectra can be a good index for evaluating the fluidity of SC lipids. However, the method for evaluation of ex vivo SC lipids has not been established. We investigated the details of the ESR methods. A glass plate using a cyanoacrylate resin was used to strip the SC lipids. A single-chain aliphatic spin probe, 5-Doxylstearic acid (5-DSA), was used. The SC samples were incubated in the 0.001% 5-DSA in a 0.1% ethanolic aqueous solution for 60 min at 37℃. After the incubation, an ESR glass holder with the incubated SC sample was mounted in the ESR cavity. The newly designed ESR glass holder improved sample preparations as well as ESR measurements. ESR spectra of the SC samples were fully analyzed using a slow-tumbling simulation. The order parameter obtained by the simulation showed depth dependence of SC lipids as a function of depth in the SC. Thus, we established sample preparations of SC lipids and precise ESR measurements and spectral analyses. In addition, we found depth dependence of the ex vivo SC lipids ordering for the first time.