Design, synthesis, characterization and bioactivity evaluation of polyglycerol-grafted Fe3O4 nanoparticles

The development of drug delivery nano-systems has improved the drug bioavailability while reducing their adverse side effects. Among them, iron oxide nanoparticles have gained lots of attention due to their applications as contrast agent in MRI technique as well as being targeted through an external magnetic field. The biological properties of these nanoparticles have been improved through surface modifications by different kinds of polymers. Hyperbranched polymers are of great interest due to existence of plenty of surface functional groups which could be utilized in conjugation of targeting and/or tracing agents. In this study, we have synthesized iron oxide nanoparticles using thermal decomposition method, modified its surface with hyperbranched polyglycerol through ring opening polymerization and compared its biocompatibility with naked iron oxide nanoparticles. The results confirmed the synthesis of iron oxide nanoparticles with average diameter of 11 nm coated with hyperbranched polyglycerol. The comparative biocompatibility tests revealed that naked nanoparticles show cytotoxicity when the concentration reaches above 200 µg/ml, whereas they are safe when coated with hyperbranched polyglycerol.