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In this work, nano-selenium (NSe) with different shapes (wires, rods, and spherical particles) was synthesized by a wet chemical method. These synthesized products were characterized by x-ray powder diffraction (XRD) analysis, a field emission scanning electron microscope (FE-SEM) with an energy dispersive x-ray analyzer, and Raman spectroscopy. FE-SEM images revealed that nanowires with an average diameter of 30–50 nm and length of 3–5 µm, nanorods with lengths of 400–800 nm and diameters of about 20–50 nm, and spherical-shaped nanoparticles (NPs) with diameters ranging from 40 to 60 nm were successfully synthesized. The XRD and Raman analysis confirmed that all the produced NSe samples exhibited hexagonal single-phase crystalline structure with no impurity phase. All three NSe products (SeNWs, SeNRs, and SeNPs) with a concentration range of 25–150 mg/l were used to investigate the impact of shape and concentration on seed germination and seedling vigor of four different crop species, namely, green bean, okra, wheat, and radish. The results revealed that NSe at low concentrations (≤50 mg/l for SeNWs and ≤100 mg/l for SeNRs and SeNPs) can promote seed germination, plant growth, and development of all the studied crop species. However, NSe can adversely affect the growth of plants at higher concentrations (≥75 mg/l for SeNWs).

In this paper, the luminescent complex Eu(3-thenoyltrifluoroacetonate)3 was integrated with Fe3O4 and gold (Au) nanoparticles to form a multifunctional nanocomposite, Fe3O4/Au/Eu(TTA)3 (FOASET NC), for dual magnetic-photothermal therapy and biomedical imaging. Upon functionalization with amine-NH2, the FOASET NC exhibits a small size of 60–70 nm and strong, sharp emission at λmax = 614 nm, enhanced by surface plasmon resonance (SPR) of Au nanoparticles that provided an effective label for HT29 colorectal cancer cells by fluorescence microscopy imaging. In addition, a hyperthermia temperature (42–46 °C) was completely achieved by using these FOASET NCs in an aqueous solution with three heating modes for (i) Magnetic therapy (MT), (ii) Photothermal therapy (PT), and (iii) Dual magnetic-photothermal therapy (MPT). The heating efficiency was improved in the dual magnetic-photothermal heating mode.

Magnetic inductive heating (MIH) has been a topic of great interest because of its potential applications, especially in biomedicine. In this paper, the parameters characteristic for magnetic inductive heating power including maximum specific loss power (SLPmax), optimal nanoparticle diameter (Dc) and its width (ΔDc) are considered as being dependent on magnetic nanoparticle anisotropy (K). The calculated results suggest 3 different Néel-domination (N), overlapped Néel/Brownian (NB), and Brownian-domination (B) regions. The transition from NB- to B-region changes abruptly around critical anisotropy Kc. For magnetic nanoparticles with low K (K < Kc), the feature of SLP peaks is determined by a high value of Dc and small ΔDc while those of the high K (K > Kc) are opposite. The decreases of the SLPmax when increasing polydispersity and viscosity are characterized by different rates of d(SLPmax)/dσ and d(SLPmax)/dη depending on each domination region. The critical anisotropy Kc varies with the frequency of an alternating magnetic field. A possibility to improve heating power via increasing anisotropy is analyzed and deduced for Fe3O4 magnetic nanoparticles. For MIH application, the monodispersity requirement for magnetic nanoparticles in the B-region is less stringent, while materials in the N- and/or NB-regions are much more favorable in high viscous media. Experimental results on viscosity dependence of SLP for CoFe2O4 and MnFe2O4 ferrofluids are in good agreement with the calculations. These results indicated that magnetic nanoparticles in the N- and/or NB-regions are in general better for application in elevated viscosity media.

Multimodal imaging, which integrates different imaging modalities, is emerging as a promising strategy to improve both preclinical and subclinical imaging. Computed tomography (CT) and magnetic resonance imaging (MRI) are among the imaging techniques widely used in clinical practice. These imaging modalities are used to diagnose and screen disease, each providing additional and different information about the patient and pathosis. In this research, we present the development of a model that combines a hybrid nanostructure, consisting of an iron oxide core and a silver‐shell nanoparticle for dual MRI/CT imaging. Fe3O4@Ag HNPs with core‐shell structure were fabricated by reducing Ag+ on the surface of Fe3O4 (NPs) nanoparticles by seed‐growth route in the thermal decomposition method. TEM images show that the synthesized nanoparticles have a uniform spherical shape and size, with an average diameter of 15.6 nm. The hybrid nanoparticles after functionalizing the surface with polyacrylic acid (PAA) became hydrophilic and dispersed well in water. The fluid of Fe3O4@Ag@PAA HNPs has high stability in water media with NaCl salt concentrations above 200 mM and a wide pH range from 4 to 11. The fluid Fe3O4@Ag@PAA has selective cytotoxicity with IC50 value 8.42 ug/ml for Hep‐G2 cell lines, and 40.3 ug/ml for normal Vero cell lines. The results of in‐vitro MRI/CT imaging showed that the value of transverse relaxation rate r2 was 138.6 mM−1s−1 and had good X‐ray attenuation ability. With these outstanding properties, the core‐shell structured nano hybrid fluid presented in this research has the potential as a candidate for multimodal bioimaging techniques in practical applications. [ABSTRACT FROM AUTHOR]

The development of noninvasive testing techniques in medicine by combining dual‐mode Magnetic Resonance (MR)/ Computed Tomography (CT) imaging techniques will help overcome the limitations of the separated methods, leading to more accurate diagnoses. This has implications in clinical research, but currently remains a major challenge in terms of the need for a corresponding multimodal signal contrast agent. In this study, we use small size, monodispersed Fe3O4 magnetic nanoparticles as the seeds to synthesize magneto‐plasmonic Fe3O4@Au hybrid nanoparticles (HNPs) with multiple functions with core‐shell structures. The influence of the ratios of HAuCl4 and oleyamine (OLA) precursors on the shape and size of the nanoparticles (NPs) was investigated. The HAuCl4/OLA ratio of 0.2/1 is the optimal condition. The obtained NPs has an average size of 21.2 nm with a uniform spherical shape, high monodispersity. After the surface functionalization with poly(acrylic acid) (PAA), the resulting Fe3O4@Au@PAA HNPs showed excellent dispersion in water, good biocompatibility, non‐toxicity against Hep‐G2 cancer cell line and Vero healthy cell line at high test concentration. The In‐vitro test data showed that the materials with Au shell enhance X‐ray decrease even at low concentrations compared to iodine‐based commercial substances while retaining the same effect as T2 contrast agent with high transverse relaxation rate r2 (125.2 mM−1s−1). The In‐vivo MRI images of rat liver tissue demonstrated that the hybrid nanoparticles showed the contrast increases 3 times under 1.5 T magnetic field after 30 minutes of drug administration. The computed tomography measurements showed the highest Hounsfield unit (HU) of 133.5 after the hybrid nanoparticle injected for 30 minutes. The in‐vivo efficacy of Fe3O4@Au@PAA magneto‐plasmonic hybrid nanoparticles was further evaluated in the cardiac and renal organs in a mouse test model to study drug kinetics. Generally, these Fe3O4@Au@PAA hybrid nanomaterials showed great promise as a candidate for multi‐modality molecular bio‐imaging. [ABSTRACT FROM AUTHOR]

A multifunctional nanodrug system containing Fe3O4, o-carboxymethyl chitosan (OCMCs), and curcumin (Cur) has been prepared and characterized by infrared and fluorescence spectroscopy, X-ray diffraction (XRD), and field-emission scanning electron microscopy (FE-SEM). The fluorescent staining experiments showed that this system not only had no effect on the cell internalization ability of curcumin but also successfully led curcumin into the HT29 cells as expected. From real-time cell analysis (RTCA), the effect of Fe3O4/OCMCs/Cur on this cancer cell line was found to be much stronger than that of pure curcumin. This system contained magnetic particles and, therefore, could be also considered for hyperthermia therapy in cancer treatment. [ABSTRACT FROM AUTHOR]