The Local Atomic Structure of Colloidal Superparamagnetic Iron Oxide Nanoparticles for Theranostics in Oncology.

Elena Kuchma,Alexander Soldatov,Stanislav Kubrin

doi:10.3390/biomedicines6030078

Abstract

The paper contains an overview of modern spectroscopic methods for studying the local atomic structure of superparamagnetic nanoparticles based on iron oxide (SPIONs), which are an important class of materials promising for theranostics in oncology. Practically important properties of small and ultra small nanoparticles are determined primarily by their shape, size, and features of the local atomic, electronic, and magnetic structures, for the study of which the standard characterization methods developed for macroscopic materials are not optimal. The paper analyzes results of the studies of SPIONs local atomic structure carried out by X-ray absorption spectroscopy at synchrotron radiation sources and Mössbauer spectroscopy during the last decade.

Highlights

One of the modern trends in cancer treatment is the use of simultaneous diagnostics and therapy-theranostics [1]
Development of novel diagnostic tools combined with image control during the therapy opens a road for future precision medicine in cancer treatment [2]
Comparison of the energy positions of experimental XANES peaks (7185, 7226, and 7275 eV) and their intensities in the spectrum of the synthesized SPIONs with the reference ones made it possible to establish that the synthesized sample has a local atomic structure analogous to the γ-Fe2 O3 phase of macroscopic iron oxide [64]

Summary

Introduction

One of the modern trends in cancer treatment is the use of simultaneous diagnostics and therapy-theranostics [1]. As in the case of other types of nanoparticles, the characteristics of magnetic nanoparticles important for theranostics applications depend first of all on their size (shape) and fine details of their local atomic structure [12]. One of the most promising classes of magnetic nanoparticles are small nanoparticles, the size of which is so small that the domain structure can no longer be realized and, nanoparticles acquire a superparamagnetic character Such superparamagnetic nanoparticles find their important application in the theranostics of cancer diseases [14]. Since the sizes of the SPIONs sometimes reach one or two nanometers, the use of standard (for example, x-ray or electron diffraction) methods becomes difficult, because the small size of the nanoparticles results in broad diffraction reflexes and, diminishes the accuracy of determination of the atomic structure parameters.

X-Ray Absorption Spectroscopy

Mö ssbauer Spectroscopy

57 Fe Mössbauer

O4 nanoparticles

Mössbauer

Conclusions