Polyethylene glycol-coated manganese-ferrite nanoparticles as contrast agents for magnetic resonance imaging

In this work, manganese ferrite (MnFe2O4) nanoparticles (NPs) were successfully synthesized via the hydrothermal method, and the dispersibility and the biocompatibility of the product were improved by the polyethylene glycol (PEG) polymer as a coating onto the surface of the synthesized NPs. The potential of the use of the synthesized PEG-coated NPs as contrast agents in the magnetic resonance imaging (MRI) was also investigated. The XRD results showed that the monophase MnFe2O4 NPs were synthesized at the pH of 11, the temperature of 200 degrees C for 12 h (optimal conditions) via the hydrothermal method. The FE-SEM and TEM investigations showed that the hydrothermally synthesized NPs had a quite homogeneous size distribution with the average size of about 50 nm. The water-based dispersions of PEG-coated Mn-ferrite NPs showed the higher stability at pH 7 in comparison with the uncoated ones. The PEG-coated Mn-ferrite NPs showed a high saturation magnetization value (60 emu/g). An enhanced MRI contrast effect by the PEG-coated NPs was confirmed via the in vitro MRI study. Moreover, the cytotoxicity activity of the PEG-coated NPs on the HeLa cells demonstrated a high cell viability even at a 0.2 mg/ml of NPs after 48 h of incubation. Also, the in vitro hemocompatibility studies of the synthesized NPs showed that the PEG-coated NPs had no effect on the blood coagulation factors, and the red blood cell (RBC) count measured by complete blood count (CBC) tests in all the investigated concentration range. It can be concluded that, therefore, the hydrothermally synthesized PEG-coated Mn-ferrite NPs in this study can be good candidates as MRI contrast agents.