多囊泡型二氢杨梅素脂质体的制备、表征及其抑菌性能

耐药金色葡萄球菌的出现和高效抗生素的缺乏已经对食品质量与公共安全造成威胁，因此，亟需寻找一种新的治疗策略来应对日益严峻的细菌挑战。本研究采用水热提取法从藤茶提取二氢杨梅素（DMY），并以脂质体为药物载体、聚乙二醇4000为修饰剂成功制备出多囊泡型二氢杨梅素脂质体（DMY-lips）。使用紫外分光光度计、傅里叶红外光谱仪、X射线粉末衍射仪和同步热分析仪分析确定了DMY的成功包覆，并通过透射电子显微镜和纳米粒度测试仪证实了脂质体的多囊泡结构。该脂质体粒径均一，平均粒径为155 nm，载药率为42.93%。此外，抑菌实验证实脂质体的包覆提高了DMY的抑菌活性和抑菌时间，这主要是由于脂质体提高了DMY的水解度和膜渗透度。DMY-lips对金色葡萄球菌的最小抑菌浓度为0.05 mg/ml。生物扫描电镜和电导率测试实验表明DMY-lips可以破坏金色葡萄球菌的细胞壁和细胞膜，导致菌体膜内内容物流出而死亡。因此，该多囊泡型二氢杨梅素脂质体在制药行业具有巨大潜力，并有望缓解医疗系统对化学抗生素的依赖。

Preparation,characterization and antibacterial properties of multivesicular dihydromyricetin-coated liposomes

The emergence of drug-resistant Staphylococcus aureus (S. aureus) and the lack of high-efficiency antibiotics have threatened food quality and public safety. Therefore, it is urgent to find new treatment strategies to resist the increasingly severe bacterial challenge. In this work, dihydromyricetin (DMY) was obtained by using a hydrothermal extraction technology from Ampelopsis grossedentata. Then, the multivesicular dihydromyricetin-coated liposomes (DMY-lips) were prepared by using liposomes as drug carriers and polyethylene glycol 4000 as modifiers. The successful formation of DMY-lips was determined by UV-vis spectrophotometer, Fourier infrared spectrometer, X-ray powder diffractometer and simultaneous thermal analyzer. Moreover, the multivesicular structure of DMY-lips was confirmed by transmission electron microscope and dynamic light scattering. The obtained DMY-lips exhibited a uniform particle size with an average particle size of 155 nm and a drug loading rate of 42.93%. In addition, antibacterial experiments found that DMY coated liposomes will improve drug antibacterial activity and antibacterial time, which due to liposomes increase the degree of hydrolysis and membrane permeability of DMY. The minimum inhibitory concentration of DMY-lips against S. aureus is 0.05 mg/ml. Noteworthy, the results of biological scanning electron microscopy and electrical conductivity test displayed that DMY-lips can destroy the cell barrier of S. aureus, causing intracellular materials leaked, resulting in bacterial cell death. Therefore, the multivesicular dihydromyricetin-coated liposomes have great potential in the pharmaceutical industry and are expected to reduce the medical system's dependence on chemical antibiotics.