Authors: B.H. Chen, B.S. Inbaraj
Affilation: Fu Jen University, Taiwan
Pages: 341 - 343
Keywords: iron oxide nanoparticles, superparamagnetic, glycol chitosan, coating material, antibacterial activity
Superparamagnetic iron oxide nanoparticles (IONPs) are particularly attractive as antibacterial agents owing to their precise bacterial biofilm and cell targeting in vivo achieved by magnetic driving. In this work, superparamagnetic IONPs modified with water-soluble glycol chitosan (GC-coated IONPs) was synthesized by coprecipitation method, followed by characterization and evaluation of antibacterial activity. Comparison of Fourier transform infrared spectra of uncoated and GC-coated IONPs as well as their magnetization and thermogravimetric curves revealed the GC coating did occur on IONPs. Additionally, the magnetization curves showed both bare and GC-coated IONPs to be superparamagnetic with the saturation magnetization being 70.3 and 59.8 emu/g, respectively. The average diameter of synthesized IONPs as determined from the transmission electron micrograph was ~ 8–9 nm, while X-ray diffraction spectra depicted the synthesized IONPs to be single crystals belonging to magnetite. Based on the MIC values determined by agar dilution assay, both bare and GC-coated IONPs were effective against Escherichia coli ATCC 8739 and Salmonella enteritidis SE 01 compared to the commercial antibiotics linezolid and cefaclor. However, for E. coli O157:H7 TWC 01 and Staphylococcus aureus ATCC 10832, GC-coated IONPs showed higher potency than bare IONPs, which may be due to the hydrophilic nature of GC-coated IONPs.