Magnetic FeO@ZIF-8 nanoparticles as a drug release vehicle: pH-sensitive release of norfloxacin and its antibacterial activity.

Metal-organic frameworks (MOFs) have a high specific surface area and inherent biodegradability due to their unique structure and composition. As well, owing to the properties of nanomaterials and especially their magnetic features, FeO nanoparticles and MOFs composite materials have great potential in the design and application of drug release. The present work: firstly, investigated norfloxacin loading in magnetic metal organic framework (FeO@ZIF-8); and secondly, studied the release of norfloxacin and its antibacterial activity. Results showed the release efficiencies reached 97 % at 310 K after 84 h (pH 7.4). Drug release behavior was tested at various pH levels and it was found that FeO@ZIF-8 has pH-sensitive properties. Furthermore, the release model calculation illustrated that the release process fitted well to the Bhaskar model. The magnetic properties of FeO@ZIF-8 confirmed that the composite has potential application for a targeted drug delivery system. The mechanism of pH-responsive norfloxacin release was combined with diffusion, ion exchange and electrostatic repulsion. Furthermore, the antibacterial activities of FeO@ZIF-8 and NOR-FeO@ZIF-8 were tested against Escherichia coli. Results showed that FeO@ZIF-8 had good biocompatibility while NOR-FeO@ZIF-8 can deter or inhibit the actions of microorganisms.