Synthesis, self-assembly, and characterization of PEG-coated iron oxide nanoparticles as potential MRI contrast agent

Abstract

Aim: Investigated the self-assembly and characterization of novel antifouling polyethylene glycol (PEG)-coated iron oxide nanoparticles as nanoprobes for magnetic resonance imaging (MRI) contrast agent. Method: Monodisperse oleic acid-coated superparamagnetic iron oxide cores are synthesized by thermal decomposition of iron oleate. The self-assembly behavior between iron oxide cores and PEG-lipid conjugates in water and their characteristics are confirmed by transmission electron microscope, X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, and vibrating sample magnetometer. Result: Dynamic light scattering shows superparamagnetic iron oxide nanoparticles coated with PEG are stable in water for pH of 3–10 and ionic strengths up to 0.3 M NaCl, and are protein resistant in physiological conditions. Additionally, in vitro MRI study demonstrates the efficient magnetic resonance imaging contrast characteristics of the iron oxide nanoparticles. Conclusion: The result indicates that the novel antifouling PEG-coated superparamagnetic iron oxide nanoparticles could potentially be used in a wide range of applications such as biotechnology, MRI, and magnetic fluid hyperthermia.

Keywords:

• CMC
• magnetic nanoparticles
• monodisperse
• MRI
• self-assembly
• superparamagnetic iron oxide nanoparticles
• thermal decomposition

Acknowledgments

This work was partly supported by ‘211 project’ and ‘985 project’ university grant from Southeast University awarded to Dr. Xiong Fei (Nos. 4007031040 and 9207032444), National Basic Research Program of China (No. 2006CB933206), and National Natural Science Foundation of China (Nos. 60725101, 30870689, 30970754, and 20903021).

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this paper.