New insight on optical and magnetic Fe₃O₄ nanoclusters promising for near infrared theranostic applications

Abstract

Extensive efforts have been devoted to the development of a new biophotonic system using near infrared (NIR) nano-agents for non-invasive cancer diagnosis and therapy. Here, we developed a simple synthesis reaction of ligands, hydrazine, and iron(ii) chloride to fabricate Fe3O4 cluster-structured nanoparticles (CNPs) with interesting NIR photonics and high magnetization (Ms: 98.3 emu g(-1) and proton relaxivity r2: 234.6 mM(-1) s(-1)). These Fe3O4 CNPs exhibited optical absorption and reflection over all wavelengths, showing a U-shape absorption band with a low absorbance at a range of 750-950 nm and a progressive evolution in the second near infrared region. Strengthening of the scattering effect by incubating Fe3O4 CNPs with HeLa cells was observed when optical contrast enhancement was performed in an optical coherence tomography (OCT) microscope system with a laser light source at 860 nm. Using a 1064 nm laser at a low power density (380 mW cm(-2)) to excite the Fe3O4 CNPs (375 ppm[Fe]) led to a rise in the water temperature from 25 °C to 58 °C within 10 min. Finally, we present the first example of magnetomotive OCT cellular imaging combined with enhanced photothermal therapy using Fe3O4 CNPs and applying a magnetic field, which is promising for preclinical and clinical trials in the future.

Revisiting the classification of NIR-absorbing/emitting nanomaterials for in vivo bioapplications

“…These Fe 3 O 4 CNPs exhibited interesting NIR photonics for magnetomotive optical coherence tomography cellular imaging at 860 nm (~10 mW) combined with enhanced PTT using Fe 3 O 4 CNPs and a magnetic field at 1064 nm (380 mW cm − 2 ). 76 …”

Magnetic and Plasmonic Contrast Agents in Optical Coherence Tomography

“…Superparamagnetic iron oxides (SPIOs) are typically desired because they maintain strong magnetic susceptibility while lacking remanent magnetization. Thus, MMOCT contrast agents tend to have MIO cores between ~10-50nm, although larger particle clusters [27] or novel ferrofluid-filled microspheres [28] have been developed for certain applications.…”

“…Huang et al (2015) report a novel clustered magnetic nanoparticle with both light scattering properties at 860 nm for OCT imaging, and absorbing properties at 1064 nm for photothermal therapy [27]. Thus, cancer cells were shown to be both imaged and subjected to hyperthermia by the same particles.…”

New Templated Ostwald Ripening Process of Mesostructured FeOOH for Third‐Harmonic Generation Bioimaging

“…Apart from these uses in industrial, energy, and magnetic fields, few optical investigations have studied several distinct kinds of iron oxide nanomaterials, thus limiting the development of these materials as optical sensors, for microscopic imaging, and in photon‐to‐thermal therapy in photomedicine . Recently, our group and other researchers reported that surface‐modified and/or highly crystalline Fe 3 O 4 nanoparticles exhibited strong near‐infrared (NIR) absorption for efficient NIR‐to‐thermal ablation of cancerous cells at a low power within 10 min of irradiation. These unique NIR absorption properties of iron oxide–based nanomaterials were recently used in applications as fluorescent probes, polymerase chain reaction (PCR) photoheaters, and repeatable photothermal scaffolds …”