This study presents an alternative approach to directly synthesizing magnetite nanoparticles (MNPs) in the presence of Vitis vinifera, Vaccinium corymbosum, and Punica granatum derived from natural sources (grapes, blueberries, and pomegranates, respectively). A modified co-precipitation method that combines phytochemical techniques was developed to produce semispherical MNPs that range in size from 7.7 to 8.8 nm and are coated with a ~1.5 nm thick layer of polyphenols. The observed structure, composition, and surface properties of the MNPs@polyphenols demonstrated the dual functionality of the phenolic groups as both reducing agents and capping molecules that are bonding with Fe ions on the surfaces of the MNPs via –OH groups. Magnetic force microscopy images revealed the uniaxial orientation of single magnetic domains (SMDs) associated with the inverse spinel structure of the magnetite (Fe₃O₄). The samples’ inductive heating (H₀ = 28.9 kA/m, f = 764 kHz), measured via the specific loss power (SLP) of the samples, yielded values of up to 187.2 W/g and showed the influence of the average particle size. A cell viability assessment was conducted via the MTT and NRu tests to estimate the metabolic and lysosomal activities of the MNPs@polyphenols in K562 (chronic myelogenous leukemia, ATCC) cells.

The aim of this research was to evaluate the effects of UV-C light on lentil ( Lens culinaris ) and its conditioning by Spirulina . The main findings were: (i) Lentil brightness presented a significant slight variation (9%) when compared to the control (T 0 ) and UV-C (T 10 = 10 min) irradiated...

In this work, Curcuma longa L. extract has been used in the synthesis and direct coating of magnetite (Fe₃O₄) nanoparticles ~12 nm, providing a surface layer of polyphenol groups (–OH and –COOH). This contributes to the development of nanocarriers and triggers different bio-applications. Curcuma longa L. is part of the ginger family (Zingiberaceae); the extracts of this plant contain a polyphenol structure compound, and it has an affinity to be linked to Fe ions. The nanoparticles’ magnetization obtained corresponded to close hysteresis loop M_s = 8.81 emu/g, coercive field H_c = 26.67 Oe, and low remanence energy as iron oxide superparamagnetic nanoparticles (SPIONs). Furthermore, the synthesized nanoparticles (G-M@T) showed tunable single magnetic domain interactions with uniaxial anisotropy as addressable cores at 90–180°. Surface analysis revealed characteristic peaks of Fe 2p, O 1s, and C 1s. From the last one, it was possible to obtain the C–O, C=O, –OH bonds, achieving an acceptable connection with the HepG2 cell line. The G-M@T nanoparticles do not induce cell toxicity in human peripheral blood mononuclear cells or HepG2 cells in vitro, but they can increase the mitochondrial and lysosomal activity in HepG2 cells, probably related to an apoptotic cell death induction or to a stress response due to the high concentration of iron within the cell.

In this study, we synthesized magnetite nanoparticles through a modified coprecipitation route and subsequently coated them directly with Curcuma longa extract. The resulting nanoparticles were then dispersed in distilled water to create a nanofluid. The particle size distribution ranged between 9 to 18 nm according to Transmission Electron Microscopy and Dynamic Light Scattering. The nanofluid’s thermal parameters were obtained by photothermal techniques, obtaining their thermal diffusivity, effusivity, conductivity, and heat capacity per unit volume. The Thermal Wave Resonator Cavity was employed to measure the thermal diffusivity, while the Inverse Photopyroelectric photothermal technique was used to determine the effusivity value. The obtained thermal parameters were close to the carrier liquid (distilled water), being a preliminary study that can be analyzed to improve the heat transfer application in other suspension fluids.

Magnetite (Fe₃O₄) nanoparticles (MNPs) below 30 nm are considered addressable magnetic cores which can be stimulated by an external AC magnetic field. In this study, MNPs were covered directly with Curcuma longa extract from a modified coprecipitation route as an organic base. The particle size distribution ranging from 9 to 18 nm according to transmission electron microscopy (TEM) and dynamic light scattering (DLS). Two main particle size populations were found associated with particle aggregation in the samples. In addition, their thermal features were determined using photothermal techniques to obtain their thermal diffusivity, effusivity, conductivity, and heat capacity per unit volume. The thermal diffusivity and effusivity values of the MNPs were obtained using a thermal wave resonator cavity (TWRC) and inverse photopyroelectric (IPPE) photothermal techniques, respectively. The obtained thermal parameters were similar to the water thermal values because the MNPs were measured in aqueous solutions. The main goal of this study was to define the thermal response, by obtaining the thermal characterization, of MNPs in suspensions related to superparamagnetic cores and Curcuma longa coatings.