Stable Iron Oxide Nanoflowers with Exceptional Magnetic Heating Efficiency: Simple and Fast Polyol Synthesis

Abstract

Magnetically induced hyperthermia has reached a milestone in medical nanoscience and in phase III clinical trials for cancer treatment. As it relies on the heat generated by magnetic nanoparticles (NPs) when exposed to an external alternating magnetic field, the heating ability of these NPs is of paramount importance, so is their synthesis. We present a simple and fast method to produce iron oxide nanostructures with excellent heating ability that are colloidally stable in water. A polyol process yielded biocompatible single core nanoparticles and nanoflowers. The effect of parameters such as the precursor concentration, polyol molecular weight as well as reaction time was studied, aiming to produce NPs with the highest possible heating rates. Polyacrylic acid facilitated the formation of excellent nanoheating agents iron oxide nanoflowers (IONFs) within 30 min. The progressive increase of the size of the NFs through applying a seeded growth approach resulted in outstanding enhancement of their heating efficiency with intrinsic loss parameter up to 8.49 nH m 2 kg Fe −1 . The colloidal stability of the NFs was maintained when transferring to an aqueous solution via a simple ligand exchange protocol, replacing polyol ligands with biocompatible sodium tripolyphosphate to secure the IONPs long-term colloidal stabilization.

Iron–Gold Nanoflowers: A Promising Tool for Multimodal Imaging and Hyperthermia Therapy

“…A wide range of NPs has been developed for medical applications. For example, Superparamagnetic Iron Oxide Nanoparticles (SPIONs) have demonstrated exceptional characteristics as MRI CAs [ 18 , 19 , 20 , 21 ] as well as an effective energy-to-heat converter in the presence of an Alternating Magnetic Field (AMF), making them suitable for HT [ 22 , 23 , 24 , 25 ]. In fact, SPIONs are being evaluated in clinical trials, ongoing or finished, for a broad spectrum of pathologies [ 26 , 27 ].…”

Smart Magnetotactic Bacteria Enable the Inhibition of Neuroblastoma under an Alternating Magnetic Field

“…The magnetic materials used in magnetic hyperthermia must be carefully chosen. Numerous hyperthermia materials are widely artificially synthesized and decorated in order to boost heating efficiency and minimize toxicity . However, the artificially synthesized process of magnetic materials is time-consuming, and their delivery necessitates using a high-gradient magnetic field, which is incompatible with deep aggregation and targeting.…”

Magnetoliposomes Containing Multicore Nanoparticles and a New Antitumor Thienopyridine Compound with Potential Application in Chemo/Thermotherapy

“…The enhanced heating profile of multicore nanostructures has been attributed to the collective magnetic behavior that results from interparticle magnetic interactions (dipole–dipole coupling or exchange coupling) between the cores, which affects the hyperthermia efficiency. Yet, the interparticle interactions are complex and depend on single nanoparticles’ size, orientation and spacing in the aggregates [ 8 ]. The preservation of the superparamagnetic behavior by clustered nanostructures (even when their dimension exceeds the superparamagnetic limit) is also an important feature for therapeutic applications, ensuring no magnetization after the removal of the applied AC magnetic field and avoiding agglomeration [ 9 , 10 , 11 ].…”