ANALYTICAL STUDY OF EFFECT OF BILAYER INORGANIC AND ORGANIC COATING AROUND THE IRON OXIDE NANOPARTICLES ON MAGNETIC RESONANCE IMAGING CONTRAST

Background & Aims: In recent years, iron oxide nanoparticles have been used in contrast-enhanced magnetic resonance imaging for diagnosing a wide range of diseases. In order to provide biocompatibility and prevent the toxicity of the nanoparticles, using organic or inorganic coating around these nanoparticles is important for their application. The aim of this study is to investigate the effect of bilayer inorganic (aluminosilicate) and organic (polyethylene glycol) coating around the iron oxide nanoparticles on magnetic resonance imaging contrast. Materials & Methods: Iron oxide- aluminosilicate- polyethylene glycol nanocomposite with the size of 170-200 nm was prepared. Magnetic resonance imaging for different concentrations of the nanocomposite was carried out by the use of similar repetition time and different echo times. Mean signal intensities were measured based on applied concentrations, and the curves of spin-spin relaxation times plotted. Transverse relaxivity value was obtained using the slope of spin-spin relaxation rate versus concentration. Results: Reduction of signal intensity with increasing echo time was observed for all concentrations. The spin-spin relaxation time decreased as a function of the concentration. The transverse relaxivity as a parameter to show magnetic resonance imaging contrast was calculated to be 80.73 s-1.mM-1. Conclusion: Iron oxide nanoparticles with bilayer aluminosilicate and polyethylene glycol coating can provide negative contrast for magnetic resonance images due to the porous structure of the aluminosilicate, and the possibility of using the nanocomposite for drug delivery according to the presence of polyethylene glycol.