IRON OXIDE NANOCUBES ASSEMBLY ON SILVER NANOWIRE TEMPLATES TO ENHANCE MAGNETIC HYPERTHERMIA PERFORMANCE

Abstract

Iron oxide nanocubes (IONCs) represent one of the benchmark magnetic nanoparticles able to most efficiently convert magneto energy into heat for magnetic hyperthermia cancer treatment, and their heat losses can be further increased by controlling their assembly through the synthesis of ordered structures. However, achieving the alignment of nanoparticles with one-dimensional chain or columnar structures into long arrays to then study their magnetic heat losses remains still a significant challenge. This study exploits silver nanowires as high-surface-area anisotropic templates for the controlled chaining of IONCs. The surfaces of the IONCs were purposely functionalized with polyethyleneimine (IONCs@PEI) and interacted with the silver nanowires (AgNWs) surfaces via electrostatic attractions. Here, alternating current (AC) magnetometry was employed to compare heating performance expressed as specific absorption rate values between individually coated IONCs@PEI and AgNWs@IONCs@PEI composites under various magnetic field strength and frequencies. SAR values reveal that clustering of IONCs on AgNWs surfaces improves the heating efficiency under the applied magnetic field strength of 24 kA.m-1, regardless of the applied frequencies, with SAR values of AgNWs@IONCs@PEI composites outperforming those of individual IONCs@PEI. Moreover, dynamic hysteresis loops showed that the coercive field of the AgNWs@IONCs@PEI increased significantly at 24 kA.m-1, indicating the existence of strong magnetic dipolar interactions between nanoparticles. This study shows an innovative approach for guiding the orientation of magnetic nanoparticles using one-dimensional templates to enhance their heating performance.