Relaxivity of Hydrogen Protons of Water Molecules in the Aqueous Solutions of Dextran - and Chitosan - Coated Ferrite Nanoparticles

Ferrite nanoparticles were synthesized at around 4°C~25°C and coated during the synthesis process with biocompatible and biodegradable polymers, dextran or chitosan. The size of ferrite nanoparticles was determined to be 7.51nm by DLS (Dynamic Light Scattering) and TEM (Transmission Electron Microscope). The size of coated nanoparticles was increased up to 128.6nm and 67nm for dextran and chitosan coating, respectively. The relaxivity of T and T of hydrogen proton of water molecule in the aqueous solution of both uncoated and coated nanoparticles were found to be linear with the concentration of nanoparticles in the solution. We found that the relaxivity of hydrogen protons in the solution of coated nanoparticles are much faster (50 to 60 times) than those in the solution of uncoated nanoparticles. 1 2