In vitro cellular activity of maghemite/cerium oxide magnetic nanoparticles with antioxidant properties

Unveiling the physicochemical, photocatalytic, antibacterial and antioxidant properties of MWCNT-modified Ag2O/CuO/ZnO nanocomposites

Water pollution, oxidative stress and the emergence of multidrug-resistant bacterial strains are significant global threats that require urgent attention to protect human health. Nanocomposites that combine multiple metal oxides with carbon-based materials have garnered significant attention due to their synergistic physicochemical properties and versatile applications in both environmental and biomedical fields. In this context, the present study was aimed at synthesizing a ternary metal-oxide nanocomposite consisting of silver oxide, copper oxide, and zinc oxide (ACZ-NC), along with a multi-walled carbon nanotubes modified ternary metal-oxide nanocomposite (MWCNTs@ACZ-NC). The properties of the synthesized nanomaterials were characterized using Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and energy dispersive X-ray (EDX) spectroscopy. The results obtained suggested the successful synthesis of both samples, as evidenced by the morphological changes observed in the SEM images, a transmittance band at 748.02 cm-1 in the FT-IR spectrum, and a diffraction peak at 44.39° in the XRD pattern. The band gap energies were determined via diffuse reflectance spectroscopy (DRS), with a redshift observed in the absorbance edge upon the incorporation of MWCNTs. The synthesized samples were tested as photocatalysts for the degradation of rhodamine 6G (Rh-6G), with the highest degradation efficiency (99.61%) achieved by MWCNTs@ACZ-NC. Additionally, the materials were evaluated for their biological activity as antibacterial and antioxidant agents. The MWCNTs@ACZ-NC exhibited the highest antioxidant potential with an IC50 value of 59.22 μg mL-1. However, the incorporation of MWCNTs resulted in a decrease in antibacterial activity, which may be attributed to the blocking of binding sites.

Magnetic and pH-responsive magnetite/chitosan (core/shell) nanoparticles for dual-targeted methotrexate delivery in cancer therapy

Methotrexate successful therapy encounters various challenges in chemotherapy, such as poor oral bioavailability, low specificity, side effects and the development of drug resistances. In this study, it is proposed a dual-targeted nanocarrier comprising magnetite/chitosan nanoparticles for an efficient Methotrexate delivery. The formation of the particles was confirmed through morphological analysis using electron microscopy and elemental mappings via energy dispersive X-ray spectroscopy. These nanoparticles exhibited a size of ≈ 270 nm, a zeta potential of ≈ 24 mV, and magnetic responsiveness, as demonstrated by hysteresis cycle analysis and visual observations under a magnetic field. In addition, these particles displayed high stability, as evidenced by size and surface electric charge measurements, during storage at both 4 ºC and 25 ºC for at least 30 days. Electrophoretic properties were examined in relation to pH and ionic strength, confirming these core/shell nanostructure. The nanoparticles demonstrated a pH-responsive drug release as observed by a sustained Methotrexate release over the next 90 h under pH ≈ 7.4, while complete release occurred within 3 h under acidic conditions (pH ≈ 5.5). In the biocompatibility assessment, the magnetite/chitosan particles showed excellent hemocompatibility ex vivo and no cytotoxic effects on normal MCF-10 A and cancer MCF-7 cells. Furthermore, the Methotrexate-loaded nanoparticles significantly enhanced the antitumor activity reducing the half-maximal inhibitory concentration by ≈ 2.7-fold less compared to the free chemotherapeutic.

Highly efficient degradation of basic dyes using gold-coated nature-based supermagnetic iron oxide nanoparticles as eco-friendly nanocatalysts

Nowadays, organic dyes are prevalent components in wastewater discharges due to their extensive use in various industries, posing a significant threat to public health across different organisms. As a result, wastewater treatment has become an indispensable requirement. In this study, we synthesized supermagnetic iron oxide (Fe3O4 NPs) and gold-iron oxide bimetallic nanoparticles (Au@Fe3O4 BNPs) using an eco-friendly method that involved natural compounds extracted from brown Egyptian propolis. We employed UV-visible spectroscopy, FTIR, XRD, VSM, SEM, HRTEM, EDX, Zeta potential and XPS techniques to examine the optical characteristics, chemical structure, crystalline structure, magnetic properties, morphology, size, and chemical composition of these biosynthesized nanoparticles. Furthermore, these nanoparticles were used as nanocatalysts for the removal of cationic dyes. The photocatalytic results indicated high efficiency in the removal of methylene blue (MB), crystal violet (CV), and malachite green (MG) dyes from aqueous solutions using Fe3O4 NPs and Au@Fe3O4 BNPs. The removal rates of MB, CV, and MG were about 95.2% in 70 min, 99.4% in 50 min, and 96.2% in 60 min for Fe3O4 NPs, and 97.1% in 50 min, 99.1% in 30 min, and 98.1% in 50 min for Au@Fe3O4 BNPs, respectively. The study also assessed the potential anti-radical properties of the extract, Fe3O4 NPs, and Au@Fe3O4 BNPs using the DPPH assay, and the results demonstrated their antioxidant activity. Finally, these Fe3O4 NPs and Au@Fe3O4 BNPs have the potential to serve as efficient antioxidants and photocatalysts for removing basic dyes from water.

Recent trends in preparation and biomedical applications of iron oxide nanoparticles

The iron oxide nanoparticles (IONPs), possessing both magnetic behavior and semiconductor property, have been extensively used in multifunctional biomedical fields due to their biocompatible, biodegradable and low toxicity, such as anticancer, antibacterial, cell labelling activities. Nevertheless, there are few IONPs in clinical use at present. Some IONPs approved for clinical use have been withdrawn due to insufficient understanding of its biomedical applications. Therefore, a systematic summary of IONPs' preparation and biomedical applications is crucial for the next step of entering clinical practice from experimental stage. This review summarized the existing research in the past decade on the biological interaction of IONPs with animal/cells models, and their clinical applications in human. This review aims to provide cutting-edge knowledge involved with IONPs' biological effects in vivo and in vitro, and improve their smarter design and application in biomedical research and clinic trials.

Structural and functional insights in polysaccharides coated cerium oxide nanoparticles and their potential biomedical applications: A review

Cerium oxide nanoparticles have now significant presence in biomedical fields due to their wide applications; however, challenges regarding their safety and biocompatibility persist. Polysaccharides based biopolymers have inherent hydroxyl and carboxyl groups, enabling them to govern the surface functionalization of cerium oxide nanoparticles, hence their chemical and physical characteristics. Because of this, polysaccharides such as dextran, alginate, pullulan, chitosan, polylactic acid, starch, and pectin are practical substitutes for the conventional coatings used to synthesize cerium oxide nanoparticles. This review discusses the effect of biopolymer coatings on the properties of cerium oxide nanoparticles, such as size, stability, aggregation, and biocompatibility. Additionally, it also summarises various biomedical applications of polysaccharides coated cerium oxide nanoparticles, such as in bone tissue regeneration, liver inflammation, wound healing, and antibacterial and anticancer activities. Biocompatible cerium oxide nanoparticles will surely improve their applications in the biomedical field.

High Resolution Powder Electron Diffraction in Scanning Electron Microscopy

A modern scanning electron microscope equipped with a pixelated detector of transmitted electrons can record a four-dimensional (4D) dataset containing a two-dimensional (2D) array of 2D nanobeam electron diffraction patterns; this is known as a four-dimensional scanning transmission electron microscopy (4D-STEM). In this work, we introduce a new version of our method called 4D-STEM/PNBD (powder nanobeam diffraction), which yields high-resolution powder diffractograms, whose quality is fully comparable to standard TEM/SAED (selected-area electron diffraction) patterns. Our method converts a complex 4D-STEM dataset measured on a nanocrystalline material to a single 2D powder electron diffractogram, which is easy to process with standard software. The original version of 4D-STEM/PNBD method, which suffered from low resolution, was improved in three important areas: (i) an optimized data collection protocol enables the experimental determination of the point spread function (PSF) of the primary electron beam, (ii) an improved data processing combines an entropy-based filtering of the whole dataset with a PSF-deconvolution of the individual 2D diffractograms and (iii) completely re-written software automates all calculations and requires just a minimal user input. The new method was applied to Au, TbF₃ and TiO₂ nanocrystals and the resolution of the 4D-STEM/PNBD diffractograms was even slightly better than that of TEM/SAED.

Nanoantioxidants: Pioneer Types, Advantages, Limitations, and Future Insights

Free radicals are generated as byproducts of normal metabolic processes as well as due to exposure to several environmental pollutants. They are highly reactive species, causing cellular damage and are associated with a plethora of oxidative stress-related diseases and disorders. Antioxidants can control autoxidation by interfering with free radical propagation or inhibiting free radical formation, reducing oxidative stress, improving immune function, and increasing health longevity. Antioxidant functionalized metal nanoparticles, transition metal oxides, and nanocomposites have been identified as potent nanoantioxidants. They can be formulated in monometallic, bimetallic, and multi-metallic combinations via chemical and green synthesis techniques. The intrinsic antioxidant properties of nanomaterials are dependent on their tunable configuration, physico-chemical properties, crystallinity, surface charge, particle size, surface-to-volume ratio, and surface coating. Nanoantioxidants have several advantages over conventional antioxidants, involving increased bioavailability, controlled release, and targeted delivery to the site of action. This review emphasizes the most pioneering types of nanoantioxidants such as nanoceria, silica nanoparticles, polydopamine nanoparticles, and nanocomposite-, polysaccharide-, and protein-based nanoantioxidants. This review overviews the antioxidant potential of biologically synthesized nanomaterials, which have emerged as significant alternatives due to their biocompatibility and high stability. The promising nanoencapsulation nanosystems such as solid lipid nanoparticles, nanostructured lipid carriers, and liposome nanoparticles are highlighted. The advantages, limitations, and future insights of nanoantioxidant applications are discussed.

A Tri-Stimuli Responsive (Maghemite/PLGA)/Chitosan Nanostructure with Promising Applications in Lung Cancer

A (core/shell)/shell nanostructure (production performance ≈ 50%, mean diameter ≈ 330 nm) was built using maghemite, PLGA, and chitosan. An extensive characterization proved the complete inclusion of the maghemite nuclei into the PLGA matrix (by nanoprecipitation solvent evaporation) and the disposition of the chitosan shell onto the nanocomposite (by coacervation). Short-term stability and the adequate magnetism of the nanocomposites were demonstrated by size and electrokinetic determinations, and by defining the first magnetization curve and the responsiveness of the colloid to a permanent magnet, respectively. Safety of the nanoparticles was postulated when considering the results from blood compatibility studies, and toxicity assays against human colonic CCD-18 fibroblasts and colon carcinoma T-84 cells. Cisplatin incorporation to the PLGA matrix generated appropriate loading values (≈15%), and a dual pH- and heat (hyperthermia)-responsive drug release behaviour (≈4.7-fold faster release at pH 5.0 and 45 °C compared to pH 7.4 and 37 °C). The half maximal inhibitory concentration of the cisplatin-loaded nanoparticles against human lung adenocarcinoma A-549 cells was ≈1.6-fold less than that of the free chemotherapeutic. Such a biocompatible and tri-stimuli responsive (maghemite/PLGA)/chitosan nanostructure may found a promising use for the effective treatment of lung cancer.