Makhija Pooja, Kathuria Himanshu, Sethi Gautam, Grobben Bert
Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore.
Department of Pharmacy, National University of Singapore, Singapore 117543, Singapore.
Gels. 2021 Oct 21;7(4):174. doi: 10.3390/gels7040174.
Tea and coffee are popular beverages. Both are also used in topical applications, such as ultraviolet (UV) protection, anti-aging, and wound healing. However, the impact of tea and coffee extract on skin cells is minimally explored. This study investigated the direct exposure of tea and coffee extract on skin cells using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. It was found that direct exposure of tea and coffee to skin cells can be toxic at a high dose on prolonged exposure (72 h). Therefore, it was hypothesized that a formulation providing a controlled release of tea and coffee could improve their skin compatibility. Thermally cross-linked poly(acrylic acid) hydrogels loaded with tea and coffee extracts (with and without milk) were formulated and optimized. The release profiles of these hydrogels were studied at varying loading efficiency. Milk addition with tea extract retarded the tea extract release from hydrogel while minimally affecting the coffee release. This effect was due to the molecular interaction of tea with milk components, showing changes in size, zeta potential, and polydispersity index. The release study best fitted the Korsmeyer-Peppas release model. Skin cells exposed to tea or coffee-loaded hydrogel showed normal skin cell morphology under fluorescence microscopic analysis. In conclusion, the hydrogels controlled the tea and coffee release and showed biocompatibility with skin cells. It can potentially be used for skin applications.
茶和咖啡都是受欢迎的饮品。它们也都被用于局部应用，如紫外线防护、抗老化和伤口愈合。然而，茶和咖啡提取物对皮肤细胞的影响却鲜有研究。本研究使用3-(4,5-二甲基噻唑-2-基)-2,5-二苯基-2H-四氮唑溴盐（MTT）法，研究了茶和咖啡提取物对皮肤细胞的直接作用。结果发现，长时间（72小时）高剂量地将茶和咖啡直接作用于皮肤细胞可能具有毒性。因此，推测一种能控制茶和咖啡释放的制剂可以改善它们与皮肤的相容性。制备并优化了负载茶和咖啡提取物（含或不含牛奶）的热交联聚丙烯酸水凝胶。研究了这些水凝胶在不同负载效率下的释放曲线。茶提取物中添加牛奶会延缓其从水凝胶中的释放，而对咖啡的释放影响最小。这种效应是由于茶与牛奶成分之间的分子相互作用，表现为尺寸、zeta电位和多分散指数的变化。释放研究最符合Korsmeyer-Peppas释放模型。在荧光显微镜分析下，暴露于负载茶或咖啡的水凝胶中的皮肤细胞显示出正常的皮肤细胞形态。总之，这些水凝胶控制了茶和咖啡的释放，并显示出与皮肤细胞的生物相容性。它有可能用于皮肤应用。
