In this study, we developed a water-in-oil microemulsion containing vitamin A (retinol) and vitamin E (α-tocopherol), which serves as a multifunctional nanosystem that co-delivers antioxidants and displayed additive effect against acute skin inflammation. Microemulsion (ME) was prepared by mixing a surfactant blend (Tween 80 and propylene glycol, 5:1) with isopropyl myristate and water (ratio of 50:40:10, respectively). Vitamin A (0.05% w/w concentration) and/or vitamin E (0.1% w/w concentration) were incorporated into the surfactant mixture of ME by stirring with a magnetic stirrer for 30 min. This multifunctional ME displayed physical stability, with low cytotoxicity in 3T3 cell line, as well as cellular internalization into the cytosol. In vivo treatments using ME delivering α-tocopherol reduced dermal expression of TNF-α by 1.3-fold (p < 0.01), when compared to unloaded ME treatment group. When retinol was added into the ME containing α-tocopherol, it further reduced TNF-α expression by 2-fold (p < 0.001), suggesting the additive effect of vitamin E and vitamin A in the treatment against skin inflammation. In conclusion, we successfully developed the use of water-in-oil ME to pack both vitamin E and vitamin A, and demonstrated for the first time its anti-inflammatory potential when applied topically to TPA-induced inflamed skin.

在这项研究中，我们开发了一种包含维生素A（视黄醇）和维生素E（α-生育酚）的油包水微乳液，它是多功能纳米系统，可共同提供抗氧化剂并显示出对急性皮肤炎症的累加作用。通过将表面活性剂混合物（吐温80和丙二醇，5：1）与肉豆蔻酸异丙酯和水（比例分别为50:40:10）混合来制备微乳液（ME）。通过用磁力搅拌器搅拌30分钟，将维生素A（0.05％w / w浓度）和/或维生素E（0.1％w / w浓度）掺入ME的表面活性剂混合物中。这种多功能的ME表现出物理稳定性，在3T3细胞系中具有低细胞毒性，并且细胞内化到细胞质中。体内与空载ME治疗组相比，使用ME递送α-生育酚的单药治疗使TNF-α的皮肤表达降低1.3倍（p <0.01）。当将视黄醇添加到含有α-生育酚的ME中时，它会使TNF-α的表达进一步降低2倍（p <0.001），表明维生素E和维生素A在抗皮肤炎症的治疗中具有累加作用。总之，我们成功开发了油包水型ME可以包装维生素E和维生素A的用途，并首次证明了将其局部应用于TPA引起的发炎皮肤时具有抗发炎的潜力。