【作者】 梁蓉； 孙香； 杨成；

【Author】 Rong Liang;Xiang Sun;Cheng Yang;The Key Laboratory of synthetic and Biological Colloids, Ministry of Education, School of Food Science and Technology, Jiangnan University;

【机构】 合成与生物胶体教育部重点实验室江南大学化学与材料工程学院；

【摘要】 表没食子儿茶素没食子酸酯(EGCG)是茶叶中多酚的主要成分,具有抗衰老、美白等功效,但由于分子结构中含有多个酚羟基,存在稳定性差、生物利用率低的缺点,限制了其在化妆品中的应用。本研究采用类脂质体对其进行包载,旨在提高EGCG稳定性的同时,促进其经皮输送。研究结果显示,水化介质盐浓度的增加或p H的降低均会导致载体的粒径增大,且载体在碱性条件下不稳定。因此,选用去离子水为水化介质,并以12000r/min的转速高速分散1 min,可制得粒径在60 nm左右,PDI为0.189±0.020,包封率和载量分别为79.4%、7.97%的EGCG类脂质体。与EGCG水溶液相比,此载体在室温下避光保存60天后,保留率由0增加到61.2%。选用人皮肤成纤维(HSF)细胞探究EGCG类脂质体的细胞抗氧化性(CAA)效果,结果表明与EGCG水溶液相比,EGCG类脂质体的EC50值从2.6μg/mL降低到1.2μg/mL,细胞抗氧化性增强。进一步采用Franz扩散池探究EGCG类脂质体的透皮效果,结果显示,相较于EGCG水溶液、EGCG与空白类脂质体的混合物,EGCG类脂质体的透皮效果最好,角质层及角质层以下皮肤中所测得的EGCG含量均为最高。通过全反射傅里叶红外光谱对猪皮表征,显示EGCG类脂质体提高了角蛋白的水合作用,并改变了角蛋白的二级结构,从而降低了角质层的屏障功能,促进药物的经皮渗透。且随着类脂质体的透入,角质层的脂质含量提高,脂质流动性降低。因此,EGCG经类脂质体包载后,其稳定性、细胞内抗氧化性、经皮输送效果均显著提高。更多还原

【Abstract】 Epigallocatechin gallate(EGCG), as the main component of tea polyphenols, has anti-aging and whitening effects. However, with multiple phenolic hydroxyl groups in molecular structure, EGCG has the disadvantages of poor stability and low bioavailability, which limit the application of EGCG in cosmetics. In this research, EGCG was encapsulated into niosomes, and their stability and transdermal effect were characterized. The increase of salt concentration or the decrease of pH in the hydration medium could lead to the increase of the particle size of EGCG niosomes, and this system was unstable under alkaline conditions. So deionized water was choesd as the hydration medium and high-speed homogenization with speed at 12000 r/min for 1 min was used to prepare EGCG niosomes. Under the optimal conditions, the particle size of EGCG niosomes was around 60 nm, PDI was 0.189±0.020, encapsulation efficiency was 79.4% and the loading capacity was 7.97%. According to the storage experiment at room temperature, it was found that the retention rate of EGCG increased from 0 to 61.2% after storage of 60 days under dark conditions. In addition, The results of cell antioxidant activity(CAA) with human skin fibroblasts(HSF) showed that, the EC50 value of EGCG decreased from 2.6 μg/mL to 1.2 μg/mL after EGCG was encapsulated with niosomes. Furthormore, franz diffusion cell was used to investigate the transdermal effect of EGCG niosomes on pig skin. The transdermal test results showed that compared with EGCG solution and a mixture of blank niosomes and EGCG, EGCG niosomes had the best transdermal effect with the highest content of EGCG measured in stratum corneum and skin below stratum corneum. The transdermal mechanism of niosomes was investigated by using total reflection infrared spectrometer. The results showed that EGCG niosomes could improve the hydration of keratin and change the secondary structure of keratin, thus reducing the barrier function of the stratum corneum and promoting the transdermal penetration of drugs. Meanwhile, with the penetration of niosomes, the lipid content of stratum corneum increased and the lipid fluidity declined. These results showed that with the encapsulation by niosomes, the storage stability, cell antioxidant activity and transdermal effect of EGCG were improved effectively.更多还原