Yong Chunyan, Chen Xiaoqin, Xiang Qian, Li Qiang, Xing Xiaodong
College of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
Bioact Mater. 2017 Jun 7;3(1):80-86. doi: 10.1016/j.bioactmat.2017.05.008. eCollection 2018 Mar.
There is a significant need for magnetite-silver nanocomposites that exhibit durable and recyclable antimicrobial activity. In this study, magnetic iron oxide nanoparticles (FeO NPs) coated with ethylenediamine-modified chitosan/polyacrylic acid copolymeric layer (FeO@ECS/PAA) were fabricated. Subsequently, directly deposited silver (Ag) NPs procedure was carried out to form the antibacterial heterodimers of FeO@ECS/PAA-Ag NPs. The composition and morphology of the resultant nanostructures were confirmed by FT-IR, XRD, TEM and TGA. The overall length of the heterodimers was approximately 45 nm, in which the mean diameter of FeO@ECS/PAA NPs reached up to 35 nm, and that of Ag NPs was around 15 nm. The mass fraction of silver NPs in the nanocomposites was about 63.1%. The obtained FeO@ECS/PAA NPs exhibited good colloidal stability, and excellent response to additional magnetic field, making the NPs easy to recover after antibacterial tests. In particular, the FeO@ECS/PAA-Ag NPs retained nearly 100% biocidal efficiency (10-10 CFU/mg nanoparticles) for both Gram-negative bacteria and Gram-positive bacteria throughout ten cycles without washing with any solvents or water, exhibiting potent and durable antibacterial activity.
迫切需要具有持久且可回收抗菌活性的磁铁矿-银纳米复合材料。在本研究中，制备了包覆有乙二胺改性壳聚糖/聚丙烯酸共聚物层的磁性氧化铁纳米颗粒（FeO NPs）（FeO@ECS/PAA）。随后，进行直接沉积银（Ag） NPs 步骤以形成 FeO@ECS/PAA-Ag NPs 的抗菌异二聚体。通过傅里叶变换红外光谱（FT-IR）、X 射线衍射（XRD）、透射电子显微镜（TEM）和热重分析（TGA）确认了所得纳米结构的组成和形态。异二聚体的总长度约为 45 nm，其中 FeO@ECS/PAA NPs 的平均直径达到 35 nm，Ag NPs 的平均直径约为 15 nm。纳米复合材料中银 NPs 的质量分数约为 63.1%。所制备的 FeO@ECS/PAA NPs 表现出良好的胶体稳定性以及对额外磁场的出色响应，使得 NPs 在抗菌测试后易于回收。特别是，FeO@ECS/PAA-Ag NPs 在十个循环中对革兰氏阴性菌和革兰氏阳性菌均保持近 100%的杀菌效率（10 - 10 CFU/mg 纳米颗粒），无需用任何溶剂或水洗涤，展现出强大且持久的抗菌活性。
