抄録
In our laboratory, secondary ion mass spectrometry (SIMS) technique has been used for the analysis of surface contaminants, surface adsorbates, and the penetration of agents, and for the investigation of surface degradation and damage of both materials and biological samples. In this paper, the applications of SIMS for hair and skin researches are explained. The outermost surface of human hair is covered with a thin layer of fatty acids, which plays an important role in creating the feeling of smoothness, and surface hydrophobicity. In this study, changes in fatty acids were characterized using time-of-flight secondary ion mass spectroscopy (TOF-SIMS) in order to investigate hair damage. In the skin research, the penetration of cosmetic ingredient was examined. The surface of skin is the stratum corneum, which works as a barrier against both external stimuli and transepidermal water loss. It was found that treatment with synthetic pseudo-ceramide (sphingolipid E; SLE) is effective for improving the barrier function. TOF-SIMS and Nano-SIMS studies revealed that the SLE penetrated into the stratum corneum via an inter-cellular pathway, and that the barrier function was improved by replenishing intercellular lipids at damaged sites on the stratum corneum.
