Composites of magnetite nanoparticles encapsulated with polymers attract interest for many applications, especially as theragnostic agents for magnetic hyperthermia, drug delivery, and magnetic resonance imaging. In this work, magnetite nanoparticles were synthesized by coprecipitation and encapsulated with different polymers (Eudragit S100, Pluronic F68, Maltodextrin, and surfactants) by nano spray drying technique, which can produce powders of nanoparticles from solutions or suspensions. Transmission and scanning electron microscopy images showed that the bare magnetite nanoparticles have 10.5 nm, and after encapsulation, the particles have approximately 1 μm, with size and shape depending on the material’s composition. The values of magnetic saturation by SQUID magnetometry and mass residues by thermogravimetric analysis were used to characterize the magnetic content in the materials, related to their magnetite/polymer ratios. Zero-field-cooling and field-cooling (ZFC/FC) measurements showed how blocking temperatures of the powders of the composites are lower than that of bare magnetite, possibly due to lower magnetic coupling, being an interesting system to study magnetic interactions of nanoparticles. Furthermore, studies of cytotoxic effect, hydrodynamic size, and heating capacity for hyperthermia (according to the application of an alternate magnetic field) show that these composites could be applied as a theragnostic material for a non-invasive administration such as nasal.

New materials from silk fibroin (FS-Ox) and chitin (CT-Ox) functionalized with Oxone^® salt were developed for application in the synthesis of Knoevenagel adducts. The experiments were performed using benzaldehyde derivatives, malononitrile, and a mixture of water and ethanol as green solvents. The efficiency of conventional and microwave irradiation as heating sources for this reaction was also investigated. When the reactions were performed for 60 min under optimized conditions with conventional heating, twelve Knoevenagel adducts 2a–l were obtained, with good yields for both catalysts (CT-Ox 60–98% and FS-Ox 71–98%). When microwave irradiation was used, the reaction periods were reduced twelvefold, with the same Knoevenagel adducts with good CT-Ox (39–99%) and FS-Ox (35–99%) yields obtained in most cases. The reuse of these materials as catalysts in successive reactions was also evaluated, and CT-Ox FS-Ox were successfully used for 4 and 2 cycles, respectively. The results presented prove the efficiency of the CT-OxFS-Ox catalyst as a promising low-cost and reusable material with suitable catalytic properties to be applied in the aldol condensation reaction in a sustainable way.

Breast cancer, a highly prevalent malignancy among women, continues to pose a significant global health challenge, as conventional therapies are often limited by adverse effects. This study developed and evaluated nanostructured lipid carriers (NLCs) encapsulating fatty acid amides (FAAs) semi-synthesized from andiroba oil and combined with silk fibroin (SF) as a novel therapeutic strategy. Methods: FAAs were synthesized via direct amidation and characterized by GC-MS, FT-IR, and ¹³C NMR. These fatty acid amides were then incorporated into NLCs containing SF. The formulation was evaluated for its physicochemical stability, cell selectivity, and cytotoxicity against 4T1 murine breast cancer cells and healthy human fibroblasts. Results: The NLC-FAA/SF formulation exhibited physicochemical stability (average particle size: 136.9 ± 23.6 nm; zeta potential: −8.3 ± 12.0 mV; polydispersity index: 0.19 ± 0.04), indicating a monodisperse and stable system. In vitro cytotoxicity assays demonstrated high selective activity against 4T1 murine breast cancer cells (IC₅₀ = 0.18 ± 0.06 μg/mL) and negligible toxicity to healthy human fibroblasts. Molecular docking studies revealed favorable interactions between the FAAs and cannabinoid receptors CB1 and CB2, with unsaturated FAAs showing higher binding scores and stability, suggesting their potential as cannabinoid receptor ligands. These findings highlight NLC-FAA/SF as a promising, selective, and effective nanoplatform for breast cancer treatment, warranting further investigation into its mechanism of action and in vivo efficacy.