Enhancement and Tunability of Plasmonic-Magnetic Hyperthermia through Shape and Size Control of Au:Fe₃O₄ Janus Nanoparticles

Abstract

Nanohyperthermia therapies have appeared as a promising alternative for the treatment of diverse cancer tumors. Multifunctional nanosystems offer a step forward in these therapies. They harness more efficient and multistimuli hyperthermia for low-dose application, as well as supplementary functions for imaging, targeting, controlled release, and sensing. Among them, Janus Au:Fe 3 O 4 nanoparticles (JNPs) are highly versatile and a prominent example for dual photo-and magnetothermia capabilities. To achieve the highest efficiencies of these nanomaterials, which allow low-dose applications, optimization in terms of size and shape is imperative. Here, we have expanded the synthesis of Janus nanostructures and carried out a systematic study to understand the structure−performance relationship and improve their hyperthermia efficiency. JNPs were synthesized by seed-mediated growth processes to obtain Janus nanostars (JNSs) and Janus nanospheres (JNSphs) with controlled sizes, together with initial heterodimers and indented F 3 O 4 NPs. The hyperthermia abilities were then evaluated using AC magnetometry and under near-infrared laser irradiation. The results showed a clear effect of size and shape on the tuning of both magnetothermia and photothermia. Iron oxide size showed the biggest effect on magnetothermia, which could be tuned by the size and shape of the gold component. Likewise, for photothermia, JNSs offered the best performance and a clear correlation between the proximity of the plasmonic band to the irradiation source and their photothermal performance, modulated by the presence of iron oxide. A SAR max of 3 kW g −1 for the strongest field and frequency tested, 0.48 kW g −1 for biological safety limits in magnetothermia, and 8.3 kW g −1 per W cm −2 of applied light for photothermia were obtained. The acquired results support the proper selection of the best JNPs for dual hyperthermia and allow one to set up the design rules for obtaining more efficient multifunctional nanosystems, opening new avenues toward advanced heating-based therapies.

Magnetic–Plasmonic Nanocomposites as Versatile Substrates for Surface–enhanced Raman Scattering (SERS) Spectroscopy

“…The second approach involves functionalizing the surface of magnetic NPs and then growing a plasmonic shell using various plasmonic precursors and reducing agents [17] . Depending on the specific SERS application, these nanocomposites can also be transformed into anisotropic morphologies using post–modification methods [18] …”

“…[17] Depending on the specific SERS application, these nanocomposites can also be transformed into anisotropic morphologies using post-modification methods. [18] An essential aspect of MP nanocomposite production is the interaction between the magnetic and plasmonic components. This interaction can affect the distribution of plasmonic material on the magnetic core and alter the plasmonic resonance properties.…”

Enhancement of skin tumor laser hyperthermia with Ytterbium nanoparticles: numerical simulation

“…LHT enables the targeted treatment of limited regions while minimizing damage to surrounding healthy tissues [10]. Hyperthermia therapies are classified into two types: photothermia and magnetothermia [11]. Magnetic nanoparticles possess distinctive characteristics that allow for the extended positioning of the heat source deep inside the tumour by intratumoral injection guided by imaging.…”