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The synthesis of nanomaterials using plant extracts is considered to be a safer, environmentally friendly, and cost‐effective alternative method. In this work, Eysenhardtia polystachya (EP) extract and choline chloride/urea (ChCl/urea)‐based deep eutectic solvent (DES) were used for the synthesis of gold nanoparticles (AuNPs), without an additional stabilizing agent, which is of great interest in the field of biomedicine. The antioxidant capacity of the extract and the phenolic content, involved in the reduction of Au3+ ions of the precursor were evaluated. The AuNPs were characterized by ultraviolet‐visible spectroscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, dynamic light scattering, ζ‐potential, confocal laser scanning microscopy, scanning and transmission electron microscopy. The nanoparticles are mostly quasi‐spherical shape, with a multiply‐twinned structure, an average particle size of 36 nm, and a characteristic absorption peak at 545 nm. The colloidal stability was confirmed with a ζ‐potential value of −32.8 mV. Finally, the AuNPs were tested for their potential in cancer therapy using human prostate adenocarcinoma PC‐3 cells. The anti‐inflammatory activity of the EP extract and AuNPs was also evaluated. The results showed that the synthesized AuNPs could potentially induce cell death and have an anti‐inflammatory effect. [ABSTRACT FROM AUTHOR]

For the first time, this study shows the nanoarchitectonic process to obtain an acetogenin-enriched nanosystem (AuNPs-Ac) using an aqueous extract from Annona cherimola Mill (ACM) composed of gold nanoparticles embedded in an organic matrix that acts as stabilizing agent and presents anti-inflammatory activity and cytotoxical effect against HepG2 cell line, promoting apoptosis. The synthesis of AuNPs-Ac was confirmed by x-ray diffraction analysis, showing metallic gold as the only phase, and the scanning transmission microscope showed an organic cap covering the AuNPs-Ac. Fourier-transformed infrared suggests that the organic cap comprises a combination of different annonaceous acetogenins, alkaloids, and phenols by the presence of bands corresponding to aromatic rings and hydroxyl groups. High-Performance Liquid Chromatography has demonstrated the presence of annonacin, a potent acetogenin, in the extract of ACM. An in vitro anti-inflammatory activity of the extract of ACM and the AuNPs-Ac was performed using the albumin denaturation method, showing a nonlinear response, which is better than sodium diclofenac salt in a wide range of concentrations that goes from 200 to 400 μ g ml−1 with both samples. The viability assay was studied using trypan blue, treating IMR90 and HepG2 at different concentrations of AuNPs-Ac. The results defined a median lethal dose of 800 μ g ml−1 against HepG2 through apoptosis according to the ratio of caspase-cleaved 9/alpha-tubulin evaluated. It was also demonstrated that the nanosystem presents a higher cytotoxic effect on the HepG2 cell line than in IMR90, suggesting a targeted mechanism. In addition, the nanosystem performs better than using only the extract of ACM in the anti-inflammatory or antiproliferative test, attributed to their higher surface area. [ABSTRACT FROM AUTHOR]

Rechargeable Zn–air batteries (ZABs) are safe energy storage systems, making them attractive for different applications, while their attractiveness can be boosted by adding natural constituents for eco-friendly disposal. In this work, biopolymeric hydrogels (biohydrogels) were synthesized using deep eutectic solvents (DESs), poly(itaconic acid) (PIA), and polysaccharides cross-linked with 2-hydroxyethyl methacrylate (HEMA). Three biohydrogels were studied, one based on alginate from Sargassum (PIA–ALG), another on inulin from Dahlia tubers (PIA–INU), and the third on dextran from Leuconostoc spp. (PIA–DEX), chosen due to their eco-friendly, cost-effective, and excellent water retention properties. Among these, PIA–INU presents pH-dependent water swelling absorption and an amorphous structure, both beneficial properties in applying biohydrogels as bioelectrolytes. These biohydrogels were then tested in a ZAB by mixing them with 6 M KOH solutions, displaying low internal resistances (below 7 Ω cm2). The ZAB assembled with 3 wt% of PIA–INU showed the best performance. It presented an open circuit voltage of 1.44 V, a current density of 112 mA cm−2@0.6 V, and a maximum power density of 62 mW cm−2. Additionally, it presented high rechargeability, being functional for more than 1600 cycles. According to post-mortem analyses, the long life of the battery can be attributed to the ability of this biohydrogel to decrease zinc issues such as shape changes and passivation. [ABSTRACT FROM AUTHOR]

The encapsulation of magnetic nickel nanowires (NiNWs) with gelatin is proposed as an alternative for optical label detection. Magnetic nanowires can be detected at very low concentrations using light-scattering methods. This detection capacity could be helpful in applications such as transducers for molecular and biomolecular sensors; however, potential applications require the attachment of specific binding molecules to the nanowire structure. In the present study, a method is presented which is helpful in coating magnetic nanowires with gelatin, a material with the potential to handle specific decoration and functionalization of the nanowires; in the first case, silver nanoparticles (AgNPs) are efficiently used to decorate the nanowires. Furthermore, it is shown that the synthesized gelatin-coated particles have excellent detectability to the level of 140 pg/mL; this level of detection outperforms more complex techniques such as ICP-OES (~3 ng/mL for Ni) and magnetoresistance sensing (~10 ng/mL for magnetic nanoparticles). [ABSTRACT FROM AUTHOR]