Seunghee Shin (Yonsei University)

Seunghee Shin (Yonsei University)

Seunghee Shin (Yonsei University)

Myeong Hee Moon (Yonsei University)

The stratum corneum, the outermost layer of human skin, functions as a primary barrier against external environmental factors. This layer is predominantly composed of lipids, including ceramides and glycerolipids, which are crucial for maintaining skin integrity and barrier function. Tape stripping is a widely used method for skin sampling by sequentially applying and removing adhesive tape. Due to various factors influencing lipid removal by each tape strip, a standardized sampling procedure is essential. This study aimed to optimize the tape stripping method for skin lipidomics using nanoflow ultrahigh performance liquid chromatography-electrospray ionization tandem mass spectrometry (nUHPLC-ESI-MS/MS). Comparative analysis revealed significant variations in the lipid composition of different body regions such as the forearm, forehead, cheek, and neck. The sequential tape stripping analysis demonstrated layer-dependent variations in the lipid composition and amount, revealing a decreasing trend of the identified numbers and normalized amount of lipids from the outermost to the inner layers. Initial findings indicated that lipid species identified decreased significantly after the sixth sequential tape strip from the same spot. To overcome the layer-to-layer variation in lipid composition, a pooling method of different tape strips was adopted. Extracts from the first three or five consecutive layers were pooled, respectively, and analyzed. This approach resulted in the identification of over 50 additional lipid species in the pooled samples compared to individual tape strip extracts. Matrix effect and extraction recovery analyses confirmed the reliability of the optimized method. Therefore, sample pooling was adopted to establish the most representative tape stripping method that accurately reflects skin lipid composition and avoids loss of quantifiable lipids.

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