Institute of Allergology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
Allergology and Immunology, Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Berlin, Germany.
Int J Cosmet Sci. 2024 Aug;46(4):578-589. doi: 10.1111/ics.12971.
The integrity of the stratum corneum (SC) is crucial for the skin's barrier function, protecting against environmental stressors and minimizing transepidermal water loss. Advances in skincare formulations have introduced multilamellar systems designed to emulate the SC's lipid composition and organization. This study hypothesizes that the application of a multilamellar cream will significantly impact the SC's lipid content and lamellar structure, thereby enhancing the epidermal barrier.
A saturated phosphatidylcholine-based multilamellar cream was applied to a cohort of adult subjects with very dry skin. Electron microscopy was utilized to analyse the micro-morphology of the cream and its integration into the lipid-depleted SC. Lipid analysis was conducted to quantify changes in the intercellular lipid matrix.
Transmission-electron microscopy (TEM) imaging demonstrated that the multilamellar cream possesses a structured arrangement comparable to the natural SC architecture. Short-term application revealed a time-dependent restoration of lipid bilayers, while a 14-day regimen showed a marked increase in lipid lamellae density and length within the SC. Lipid analysis indicated a significant increase in total lipid content, with notable enhancements in ceramide and free fatty acid levels, without altering cholesterol levels. Lipid ratio analysis further confirmed the rebalancing of the SC's lipid composition.
The multilamellar cream selectively increased specific lipids critical for barrier function, suggesting an action mechanism that aligns with the skin's natural regulatory processes. This selective augmentation indicates the potential of the formulation to not only restore but also enhance the epidermal barrier, with the maintenance of physiological lipid ratios suggesting compatibility with intrinsic repair mechanisms.
The study confirms that a multilamellar cream can significantly improve the SC's lipid composition and structural integrity, indicating enhanced barrier function. They are pivotal for skincare professionals, dermatologists, and product developers, enriching the understanding of multilamellar creams' benefits and applications in improving epidermal barrier function.
角质层（SC）的完整性对于皮肤的屏障功能至关重要，可防止环境压力和最大程度减少经表皮水分流失。护肤品配方的进步引入了多层系统，旨在模拟 SC 的脂质组成和结构。本研究假设应用多层乳膏会显著影响 SC 的脂质含量和层状结构，从而增强表皮屏障。
将基于饱和磷脂酰胆碱的多层乳膏应用于一组皮肤非常干燥的成年受试者。电子显微镜用于分析乳膏的微观形态及其与脂质耗竭的 SC 的整合。进行脂质分析以量化细胞间脂质基质的变化。
透射电子显微镜（TEM）成像表明，多层乳膏具有类似于天然 SC 结构的结构化排列。短期应用显示脂质双层具有时间依赖性恢复，而 14 天方案显示 SC 内脂质层的密度和长度明显增加。脂质分析表明总脂质含量显著增加，神经酰胺和游离脂肪酸水平显著提高，而胆固醇水平不变。脂质比率分析进一步证实了 SC 脂质组成的再平衡。
多层乳膏有选择性地增加了对屏障功能至关重要的特定脂质，表明其作用机制与皮肤的自然调节过程一致。这种选择性增加表明该配方不仅具有恢复作用，而且具有增强表皮屏障的潜力，维持生理脂质比率表明与内在修复机制的相容性。
该研究证实，多层乳膏可以显著改善 SC 的脂质组成和结构完整性，表明屏障功能增强。它们对皮肤护理专业人员、皮肤科医生和产品开发人员至关重要，丰富了对多层乳膏在改善表皮屏障功能方面的益处和应用的理解。
