Metallic Iron Nanoparticles for MRI Contrast Enhancement and Local Hyperthermia

Abstract

Current magnetic-nanoparticle technology is challenging due to the limited magnetic properties of iron oxide nanoparticles (IONPs). Increasing the saturation magnetization of magnetic nanoparticles may permit more effective development of multifunctional agents for simultaneous targeted cell delivery, magnetic resonance imaging (MRI) contrast enhancement, and targeted cancer therapy in the form of local hyperthermia. We describe the synthesis and characterization of novel iron-based nanoparticles (FeNPs) coated with biocompatible biscarboxyl-terminated poly(ethylene glycol) (cPEG). In comparison to conventional IONPs similar in size (10 nm), FeNPs particles have a much greater magnetization and coercivity based on hysteresis loops from sample magnetometry. Increased magnetization afforded by the FeNPs permits more effective generation of local hyperthermia than IONPs when subjected to an oscillating magnetic field in a safe frequency range. Furthermore, FeNPs have a much stronger shortening effect on T 2 relaxation time than IONPs, suggesting that FeNPs may be more effective MRI contrast agents. Next-generation FeNPs with a biocompatible coating may

Magnetic hyperthermia investigation of cobalt ferrite nanoparticles: Comparison between experiment, linear response theory, and dynamic hysteresis simulations

“…1 Several applications have been reported, ranging from stem cell labeling, atherosclerosis, or metastasis detection, to cancer treatment. [1][2][3][4][5][6][7][8][9][10][11][12] Cancer treatment with magnetic nanoparticles is based upon the magnetic hyperthermia phenomenon, which consists of an increase on the temperature of magnetic nanoparticles (heat centers) due to the interaction of their magnetic moments with an alternating magnetic field. The heating process is related to hysteresis losses which are proportional to the hysteresis loop area.…”

“…1, [8][9][10][11]18 A possible material for such application is cobalt ferrite, which has both enhanced anisotropy and saturation magnetization. In addition, this nanomaterial has been found to have multifunctional applications spanning from room-temperature spin filtering, 19 multiferroic devices 20,21 to even MRI contrast agents.…”

Preparation and control of the formation of single core and clustered nanoparticles for biomedical applications using a versatile amphiphilic diblock copolymer

“…Since the Ms value has been normalized for the amount of iron, the higher magnetization of the IONP clusters reveals that the unique morphology of the clusters prepared with our amphiphilic copolymer may enhance the magnetic properties of IONP, which is not possible for a single particle counterpart. We believe that the ultrahigh Ms value of the clustered IONPs may offer greater capabilities for biomedical applications, such as MRI contrast enhancement, hyperthermia therapy [38], and magnetic separations [39].…”

Preparation of tunable-sized iron nanoparticles based on magnetic manipulation in inert gas condensation (IGC)

“…[7][8][9] NPs, as is well known, exhibit properties that can be tremendously distinct from their macroscopic counterparts, 10 and the properties as well as surface chemistry then show strong sensitivity to particle size and shape. 11,12 The size-dependent properties can originate from the high surface-to-volume ratio, and influences by particle shapes can be attributed to the distinct crystallographic surfaces that enclose the NP.…”