Superparamagnetic Iron Oxide Nanoparticles (SPIONs): Synthesis and Surface Modification Techniques for use with MRI and Other Biomedical Applications

Abstract

Superparamagnetic iron oxide nanoparticles (SPIONs) comprise a fundamental technology class within the emerging field of nanomedicine, and have been extensively researched for cancer imaging and therapy. This review article will discuss the chemistry and design considerations associated with the synthesis of SPIONs and their incorporation into pharmaceutical formulations. Specific synthesis methods discussed include coprecipitation, thermal decomposition, microemulsion and solvothermal synthesis, as well as surface treatments and encapsulations to improve the nanoparticle biocompatibility and efficacy. Emerging applications of novel particle designs as MRI contrast agents are also discussed.

The effects of synthesis method on the physical and chemical properties of dextran coated iron oxide nanoparticles

“…The magnetic differences of iron oxide nanoparticles compared to the bulk material are a consequence of inter and intra particle interactions. Additionally, when the iron oxide nanoparticles are of a single domain, they exhibit superparamagnetism by which they do not retain magnetization in the absence of an externally applied magnetic field [3]. …”

“…The coating layer can also be designed to increase the circulation time and the biocompatibility of the nanoparticles for use as MRI contrast agents and magnetically mediated hyperthermia [6, 7]. Dextran is a biocompatible long chain hydrophilic polymer composed of glucose with mostly α-1, 6 glycoside linkages [8] that strongly physisorb to magnetite nanoparticles in alkaline solutions via non-covalent interactions of the abundant hydroxyl groups resulting in enmeshed nanoparticle cores [3]. The hydroxyl groups of dextran can then be easily crosslinked and functionalized with primary amines to attach various targeting ligands, peptides, or probes [9-12].…”

The Nanopharmacology and Nanotoxicology of Nanomaterials: New Opportunities and Challenges

“…For cancer treatment, nanotheranostic platforms can provide advanced diagnostics, hyperthermia treatment and targeted delivery of anticancer drugs [13]; superparamagnetic iron oxide nanoparticles (SPIONs) are an example of such platforms [14,15]. SPIONs have also been developed as a part of the MULTIFUN EU consortium (http://www.multifun-project.eu/) [16] and offer distinct advantages over other drug delivery platforms used with anticancer medications: a) the pharmacokinetics of SPIONs are easily determined using non-invasive imaging techniques such as nuclear magnetic resonance (NMR); b) SPIONs can easily be guided to cancer tissues using the electromagnetic field (EM); c) SPIONs can selectively generate energy to destroy cancer cells; and d) when functionalized with antibodies against cancer biomarkers, SPIONs can selectively deliver a "cocktail" of therapeutic pharmaceuticals (Fig.…”

SPIO‐Au core–shell nanoparticles for promoting osteogenic differentiation of MC3T3‐E1 cells: Concentration‐dependence study

“…For example, nanomaterial scaffolds have been extensively developed to mimic the structure of natural extracellular matrices and to provide a three‐dimensional (3D) network and sufficient support for cell growth . As a highly sensitive contrast agent, superparamagnetic iron oxide (SPIO) NPs have been used to label various kinds of cells such as chondrocytes, mesenchymal stem cells (MSCs), and adipose derived stem cells (ADSCs) . By the effective labeling with SPIO NPs, the localization of cells inside the scaffolds can be noninvasively visualized using magnetic resonance imaging (MRI) .…”