Effect of biomimetic templates on the magneto-structural properties of Fe3O4 nanoparticles

Abstract

In this study, water dispersible iron oxide nanoparticles (IONPs) were synthesized in three different templates using a combination of proteins (collagen and bovine serum albumin), amino acids (glycine and glutamic acid) and a biocompatible polymer (poly vinyl alcohol). A stringent control on the morphology of IONPs that is reproducible and scalable at ambient conditions is obtained. Detailed structural characterization and the template effect on magneto-structural properties of IONPs have been studied. Magnetic measurements showed variation in magnetic properties and relaxation behavior with change in the chemical environment (the attachment of surface ligands confirmed from the Fourier transform infrared spectra); Mössbauer studies revealed monopole and magnetic hyperfine interactions playing an important role that could be attributed to template dependency. The increase of particle size coupled with decrease in hydrodynamic diameter decreases demagnetizing interactions between nanoparticles which increase the specific absorption rate in in vitro hyperthermia, thus the highest specific absorption rate (139 Watts per g) observed in template 1. Magnetic resonance imaging (MRI) studies also showed transverse relaxivity of 543.9 ml s⁻¹ mg⁻¹ for nanoparticles in template 1. Considering the anisotropy energy barrier, particle size and hydrodynamic diameter we conclude that template 1 is the best for potential applications in biomedicine.