An ultra-sensitive T2-weighted MR contrast agent based on Gd3+ ion chelated Fe3O4 nanoparticles

A versatile theranostic magnetic polydopamine iron oxide NIR laser-responsive nanosystem containing doxorubicin for chemo-photothermal therapy of melanoma

Theranostics nanoparticles (NPs) have recently received much attention in cancer imaging and treatment. This study aimed to develop a multifunctional nanosystem for the targeted delivery of photothermal and chemotherapy agents. Fe3O4 NPs were modified with polydopamine, bovine serum albumin, and loaded with DOX via a thermal-cleavable Azo linker (Fe3O4@PDA@BSA-DOX). The size of Fe3O4@PDA@BSA NPs was approximately 98 nm under the desired conditions. Because of the ability of Fe3O4 and PDA to convert light into heat, the temperature of Fe3O4@PDA@BSA NPs increased to approximately 47 °C within 10 min when exposed to an 808 nm NIR laser with a power density of 1.5 W/cm2. The heat generated by the NIR laser leads to the breaking of AZO linker and drug release. In vivo and in vitro results demonstrated that prepared NPs under laser irradiation successfully eradicated tumor cells without any significant toxicity effect. Moreover, the Fe3O4@PDA@BSA NPs exhibited the potential to function as a contrasting agent. These NPs could accumulate in tumors with the help of an external magnet, resulting in a significant enhancement in the quality of magnetic resonance imaging (MRI). The prepared novel multifunctional NPs seem to be an efficient system for imaging and combination therapy in melanoma.

Rare-Earth Doped Iron Oxide Nanostructures for Cancer Theranostics: Magnetic Hyperthermia and Magnetic Resonance Imaging

Superparamagnetic iron oxide nanoparticles (SPIONs) have been extensively investigated during the last couple of decades because of their potential applications across various disciplines ranging from spintronics to nanotheranostics. However, pure iron oxide nanoparticles cannot meet the requirement for practical applications. Doping is considered as one of the most prominent and simplest techniques to achieve optimized multifunctional properties in nanomaterials. Doped iron oxides, particularly, rare-earth (RE) doped nanostructures have shown much-improved performance for a wide range of biomedical applications, including magnetic hyperthermia and magnetic resonance imaging (MRI), compared to pure iron oxide. Extensive investigations have revealed that bigger-sized RE ions possessing high magnetic moment and strong spin-orbit coupling can serve as promising dopants to significantly regulate the properties of iron oxides for advanced biomedical applications. This review provides a detailed investigation on the role of RE ions as primary dopants for engineering the structural and magnetic properties of Fe₃ O₄ nanoparticles to carefully introspect and correlate their impact on cancer theranostics with a special focus on magnetic hyperthermia and MRI. In addition, prospects for achieving high-performance magnetic hyperthermia and MRI are thoroughly discussed. Finally, suggestions on future work in these two areas are also proposed.

Boron and Gadolinium Loaded Fe3O4 Nanocarriers for Potential Application in Neutron Capture Therapy

In this article, a novel method of simultaneous carborane- and gadolinium-containing compounds as efficient agents for neutron capture therapy (NCT) delivery via magnetic nanocarriers is presented. The presence of both Gd and B increases the efficiency of NCT and using nanocarriers enhances selectivity. These factors make NCT not only efficient, but also safe. Superparamagnetic Fe3O4 nanoparticles were treated with silane and then the polyelectrolytic layer was formed for further immobilization of NCT agents. Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray (EDX), ultraviolet-visible (UV-Vis) and Mössbauer spectroscopies, dynamic light scattering (DLS), scanning electron microscopy (SEM), vibrating-sample magnetometry (VSM) were applied for the characterization of the chemical and element composition, structure, morphology and magnetic properties of nanocarriers. The cytotoxicity effect was evaluated on different cell lines: BxPC-3, PC-3 MCF-7, HepG2 and L929, human skin fibroblasts as normal cells. average size of nanoparticles is 110 nm; magnetization at 1T and coercivity is 43.1 emu/g and 8.1, respectively; the amount of B is 0.077 mg/g and the amount of Gd is 0.632 mg/g. Successful immobilization of NCT agents, their low cytotoxicity against normal cells and selective cytotoxicity against cancer cells as well as the superparamagnetic properties of nanocarriers were confirmed by analyses above.

Smart magnetic nanopowder based on the manganite perovskite for local hyperthermia

For many medical applications related to diagnosis and treatment of cancer disease, hyperthermia plays an increasingly important role as a local heating method, where precise control of temperature and parameters of the working material is strongly required. Obtaining a smart material with "self-controlled" heating in a desirable temperature range is a relevant task. For this purpose, the nanopowder of manganite perovskite with super-stoichiometric manganese has been synthesized, which consists of soft spherical-like ferromagnetic nanoparticles with an average size of 65 nm and with a narrow temperature range of the magnetic phase transition at 42 °C. Based on the analysis of experimental magnetic data, a specific loss power has been calculated for both quasi-stable and relaxation hysteresis regions. It has been shown that the local heating of the cell structures to 42 °C may occur for a short time (∼1.5 min.) Upon reaching 42 °C, the heating is stopped due to transition of the nanopowder to the paramagnetic state. The obtained results demonstrate the possibility of using synthesized nanopowder as a smart magnetic nanomaterial for local hyperthermia with automatic heating stabilization in the safe range of hyperthermia without the risk of mechanical damage to cell structures.