헤어메니큐어로 처리한 모발의 투과전자현미경적 관찰 및 에너지분광분석

The current study examined the internal microstructural changes of cuticle and cortex of natural hair, manicure dyed hair, and manicure dyed hair after bleaching using a transmission electron microscopy. Furthermore, the elementary compositions of the hair samples were also analyzed using energy dispersive spectrometry. Results showed that the structure of the cuticle of natural hair comprised with 7 to 8 cuticle cell layers, thereby forming the A-layer, endocuticle, and exocuticle. The macrofibrils, melanin granules, cell remnants, and cell membrane complexes formed the cortex. Small holes formed by natural weathering were found on the endocuticle and borderline between melanin granules and macrofibrils. Additionally, fine gaps between the cuticle cells and continuous gaps under the separated cuticle cells in manicure dyed hair were observed. There were also many large and small holes on endocuticle layer and cortex, while no structural changes were seen in the melanin granules and macrofibrils. Several holes of 150 nm to 2 μm in diameter were found in the cuticle layer of manicure dyed hair after bleaching and many holes in the cortex were primarily observed in the intermacrofibrils and around melanin granules. Dissolved melanin granules were typically observed in the cortex close to the cuticle layer, whereas the melanin granules broke from the outside to form holes. Low electron density was observed at the center of the melanin granules due to chemical reaction of the bleach. The dissolved melanin granules were found at the surrounding area of a tyrosinase core in concentric circles, and no physicochemical changes in the surrounding macrofibrils or cortex cell membrane complexes were observed. The C, N, O, S, and Ca elements were commonly found in the natural hair, manicure dyed hair, and manicure dyed hair after bleaching, whereas Si was detected only in the manicure dyed hair after bleaching.