Wang Bailiang, Liu Huihua, Wang Zefeng, Shi Shuai, Nan Kaihui, Xu Qingwen, Ye Zi, Chen Hao
School of Ophthalmology & Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China.
J Mater Chem B. 2017 Feb 21;5(7):1498-1506. doi: 10.1039/c6tb02614a. Epub 2017 Feb 1.
Drug delivery systems play important roles in the construction of antibacterial coatings on the surfaces of biomaterials. However, excessive release of antibiotics in the environment can lead to the generation of resistant bacteria. A methoxy poly(ethylene glycol)-poly(ε-caprolactone)-chitosan (MPEG-PCL-CS) block polymer was prepared through covalent grafting of CS onto MPEG-PCL. MPEG-PCL-CS micelles were prepared and showed a high load capacity for the hydrophobic antibiotic triclosan (TCA) (∼5 wt%). Multilayer films were constructed through self-assembling TCA/MPEG-PCL-CS cationic micelles with poly(acrylic acid) (PAA). Transmission and scanning electron microscopy analyses confirmed the presence of micelles on the surface (20-40 nm). As barriers for the antibiotic, the (TCA/MPEG-PCL-CS)/PAA multilayer films contained a high load of TCA (255 μg cm). Importantly, the multilayer films showed both bacteria-triggered and pH-responsive release properties and can be used as self-defensive antibacterial coatings. Bacterial adhesion caused a local acidic environment and altered the permeability of the multilayer films, promoting drug release. Both in vitro and in vivo antibacterial tests indicated a high bactericidal activity of drug-loaded multilayer films against both E. coli and S. aureus.
药物递送系统在生物材料表面抗菌涂层的构建中发挥着重要作用。然而，抗生素在环境中的过度释放会导致耐药菌的产生。通过将壳聚糖（CS）共价接枝到甲氧基聚（乙二醇）-聚（ε-己内酯）（MPEG-PCL）上制备了甲氧基聚（乙二醇）-聚（ε-己内酯）-壳聚糖（MPEG-PCL-CS）嵌段聚合物。制备了MPEG-PCL-CS胶束，其对疏水性抗生素三氯生（TCA）具有较高的负载能力（约5 wt%）。通过将TCA/MPEG-PCL-CS阳离子胶束与聚丙烯酸（PAA）自组装构建多层膜。透射电子显微镜和扫描电子显微镜分析证实了表面存在胶束（20 - 40 nm）。作为抗生素的屏障，（TCA/MPEG-PCL-CS）/PAA多层膜含有高负载量的TCA（255 μg/cm²）。重要的是，多层膜具有细菌触发和pH响应释放特性，可作为自我防御的抗菌涂层。细菌粘附导致局部酸性环境并改变多层膜的通透性，促进药物释放。体外和体内抗菌测试均表明载药多层膜对大肠杆菌和金黄色葡萄球菌均具有高杀菌活性。
