ACS Omega最新文献

Plants are important sources of metabolites used in the cosmetics, food, and pharmaceutical industries, especially in cosmetics, where bioactive compounds offer benefits for the skin, such as protection against environmental stresses. The term “cosmeceutical” has emerged to describe products that combine aesthetic effects and dermatological treatments. With the growth of the cosmetics industry, the demand for ingredients that combat the signs of aging and oxidative stress – the main cause of skin aging – has increased. Bioactive compounds, such as phenols, flavonoids, and carotenoids, have antioxidant properties that are widely used to control the skin’s aging process, triggered by environmental factors or the body’s own metabolism, leading to excessive production of free radicals and, consequently, oxidative stress. However, incorporating these lipophilic compounds into water-based cosmetic formulas presents major challenges, including poor solubility, low stability, limited skin penetration, and rapid degradation. Nanoemulsions overcome these limitations by enabling droplet sizes of 20–200 nm through high-energy (e.g., high-pressure homogenization, ultrasonication) or low-energy (e.g., phase inversion temperature, spontaneous emulsification) methods. Their significance in cosmeceuticals lies in enhanced skin penetration, improved bioavailability of lipophilic actives, and prolonged product stability, making them ideal for antiaging creams, sunscreens, and moisturizers. This review article aims to address antioxidant compounds, their cosmetic applications, and the techniques used to obtain them, including characterization methods, validation of nanoemulsions, the main difficulties, and future prospects.

The thermal drawing process, originally developed to fabricate silica-based optical fibers, has recently been adapted to produce polymer-based, multimaterial, and multifunctional fibers. Such fibers integrate electrodes, optical waveguides, microfluidic channels, and biosensors and are emerging as promising platforms for multimodal biointerfaces. Recently, actuation has been achieved within fibers by incorporating functional components such as shape-memory alloys (SMAs), magnetic composites, and tendon wires, expanding their applications to soft robotics and medical catheters. However, such actuator fibers often suffer from high stiffness, limited degrees of freedom, and complex actuation setups due to the use of rigid materials, such as SMA or magnetic setups, for field control. To overcome the limitations of existing thermally drawn fiber-based actuator systems, this study presents the development of all-polymer soft actuator fibers based on dielectric elastomers, designed to provide enhanced mechanical compliance and increased actuation freedom. A thermoplastic polyurethane (PU) elastomer was selected as the primary material due to its compatibility with the thermal drawing process and its electroactive response under applied electric fields. The resulting dielectric elastomer actuator (DEA) fibers exhibit intrinsic softness, with an overall Young’s modulus of 37 MPa, enabling electrically controllable actuation modes with high freedom in bending, compression, and three-dimensional(3D) swirling motions. An estimated compression strain of 1.59% was achieved at a driving frequency of 1 Hz and an electrical field of 2.4 MV/m, which is consistent with literature-reported values. Furthermore, the fibers demonstrated excellent cyclic stability, maintaining a consistent actuation performance over 400 consecutive cycles. This approach provides a promising route toward flexible, scalable, and multifunctional actuator fibers for next-generation applications in soft robotics, biomedical devices, and wearable systems.

Mesoporous TiO₂ sol–gel coatings with a thickness of 122 nm and a porosity of 49% were prepared by dip-coating, followed by Cu₂O nanoparticle deposition onto the surface using a simple, one-step method: the TiO₂ coating was immersed in the reaction mixture and Cu₂O particles formed on the surface in a heterogeneous nucleation process. The crystallinity, size, shape, and structure of the samples were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, atomic force microscopy, and scanning electron microscopy. Optical properties, layer thickness, and porosity were determined by UV–vis spectroscopy and spectroscopic ellipsometry. Cu₂O nanoparticles with an oblate spheroidal shape and cubic crystal structure formed on the surface, with an average particle size of 326 nm, and the surface coverage could be controlled by the reaction time. Photoactivity of the TiO₂/Cu₂O coatings was studied in dye photodegradation tests under UV and visible light, using methyl orange dye as a model pollutant. The samples showed significant photoactivity; the amount of Cu₂O particles and their surface coverage on titania played an important role. High surface coverage could be achieved in a simple one-step deposition process using heterogeneous nucleation, resulting in enhanced photoactivity under visible light, making this method suitable to produce photoactive coatings for a variety of applications, such as air and water purification.

The widespread use of antibiotics has raised concerns about their residues in dairy products, meat, fish, and poultry, which can pose risks to human health and lead to substantial economic losses. Therefore, the rapid, sensitive, and cost-effective detection of low concentrations of various antibiotics in food samples is critical. This work reports on the fabrication of MXene fibers by coating commercial nylon yarns with Ti₃C₂, Ti₃C_1.75N_0.25, and Ti₃C_1.5N_0.5 MXenes and their use as electrodes in an impedimetric electronic tongue (e-tongue). The MXene-modified fiber-based e-tongue was employed in the detection of trace amounts of cloxacillin benzathine, tetracycline hydrochloride, and streptomycin sulfate. By treating the collected electrical resistance data, the system could differentiate the antibiotics and detect their presence in real milk samples at concentrations as low as 10 nM. The use of low-cost MXene-modified nylon fibers as electrodes, which can be fabricated through rapid and straightforward methods, enhances the scalability and practicability of the e-tongue system. This approach represents a promising and robust alternative for the sensitive detection of diverse antibiotic residues in food matrices.

Boron nitride (B₁₂N₁₂) nanocages have attracted considerable attention due to their exceptional structural stability and tunable electronic properties, making them promising candidates for gas-sensing applications. In this study, DFT-D3 calculations at the B3LYP/def2-TZVP level, including relativistic effects for yttrium (SARC-ZORA-def2-TZVP), were employed to investigate H₂ adsorption on pristine and Y-modified (doped, decorated, and encapsulated) B₁₂N₁₂ nanocages. The pristine nanocage exhibited weak physisorption (E_ads = −0.04 eV), whereas the Y@b₆₄ configuration demonstrated strong chemisorption (E_ads = −0.96 eV), pronounced electronic sensitivity (ΔE_gap = 74.94%), and a feasible recovery time (τ = 166.8 s). Analyses of electrostatic potential, molecular dynamics (1000 ps), IR, and UV–vis spectra confirmed the structural robustness and optical detectability of H₂. Furthermore, the Y@b₆₄ nanocage showed remarkable selectivity toward H₂ compared to common interfering gases (CH₄, CO, H₂S, and N₂). Overall, Y@b₆₄ combines high adsorption energy, strong sensitivity, and efficient recovery time, underscoring its potential as a selective, stable, and high-performance H₂ gas sensor.

β-Pinene, a low-cost natural product derived from agricultural waste, has shown in vitro activity against Leishmania amazonensis, but its use is hindered by unfavorable pharmacokinetic properties. Herein, we report a straightforward two-step synthesis of β-pinene-derived hydroxysulfides followed by an in vitro evaluation of their antileishmanial activity, cytotoxicity profile in mammalian cells, and in silico studies of structure–activity relationship (SAR) and ADMET properties. Initially, β-pinene was converted into its epoxide, the key intermediate of the series, through both chemoenzymatic and nonchemoenzymatic approaches. Then, we studied the thiolysis reaction by screening a series of bases and solvents. The use of NaOMe in methanol afforded the β-hydroxysulfide in 81% yield. This strategy afforded 16 novel derivatives bearing alkyl and (hetero)aryl substituents, with isolated yields ranging from 19 to 91%. The antileishmanial activity with promastigote cells showed that 11 compounds reduced parasite viability to <10% in a fixed-concentration assay (100 μM), and six displayed IC₅₀ values below 30 μM. Four derivatives were further evaluated against intracellular amastigote cells, with the para-fluoroaryl analogue emerging as a hit compound (IC₅₀ = 6.3 μM; SI > 15.9). SAR analysis revealed key physicochemical features associated with activity, highlighting the importance of lipophilicity, polar surface area, and cLogP in promoting parasite membrane penetration. Meanwhile, in silico ADMET supported their drug-likeness since no mutagenic, cardiotoxic, or hepatotoxic potential was predicted, encouraging further in vivo and mechanistic studies.

The abundance of cheap natural gas has changed the energy supply landscape and spurred efforts to find alternative sources of energy to traditional fossil fuels. Methane (CH₄) is the primary constituent of natural gas, and its C–H bond activation remains a long-standing puzzle in the chemical industry. Transition-metal oxides exhibit intrinsic Lewis acid–base properties beneficial for activating the C–H bonds of CH₄. In this work, we investigated the nonoxidative coupling of CH₄ (NOCM) to C₂ hydrocarbons on the rutile TiO₂ (110) surface at 1240 K by using density functional theory (DFT) calculations. We explored three different CC coupling pathways for the formation of ethane after the sequential activation of two CH₄ molecules. We found that CH₃/CH₃ coupling involves high activation barriers, while the formation of C₂H₅ from the coupling of CH₃/CH₂ is kinetically and thermodynamically more facile. Considering ethylene formation routes, we found that the dehydrogenation of methyl species requires high energy barriers. However, the subsequent CC coupling of CH₂/CH₂ occurs at a lower activation barrier of 1.01 eV. Moreover, our calculations revealed that the dehydrogenation of C₂H₅ to form ethylene is favored over its hydrogenation to form ethane. This work provides various mechanistic pathways that can help in designing dehydrogenation catalysts with enhanced catalytic activity. However, our results indicate that despite low barrier coupling routes, rutile TiO₂ alone is not an effective catalyst for NOCM due to the energy-intensive C–H activation and limited stability of reactive intermediates. Rutile TiO₂ may have enhanced activity and selectivity in doped configurations or as a catalyst support within multifunctional catalytic systems.

Sterilization is essential for ensuring the safety and biocompatibility of biomaterials intended for biomedical use. However, their sensitivity to sterilization methods requires careful evaluation of potential impacts on structural and functional integrity. Biopolymers such as konjac glucomannan (KGM) have emerged as promising candidates for wound healing and tissue engineering due to their favorable physicochemical properties along with improved thermal resistance and adequate mechanical properties. In this study, KGM-based films were developed and subjected to different sterilization and disinfection protocols─including autoclaving, ethylene oxide (EtO), γ irradiation, UV radiation, and 70% ethanol─and were evaluated on their physical, chemical, mechanical, and biological properties by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), mechanical analyses and in vitro cytotoxicity. The results showed that γ and UV irradiation induced the most pronounced changes in film properties, whereas autoclaving and EtO better preserved the materials’ integrity. Additionally, 70% ethanol demonstrated satisfactory performance as a disinfectant. These findings underscore the importance of selecting appropriate sterilization methods to ensure the efficacy and functionality of KGM-based biomaterials.

Vitamin-enriched gummies are gaining popularity due to their convenience and consumer appeal; however, incorporating water-soluble and unstable vitamins such as vitamin C remains challenging because of its poor stability and rapid degradation during processing. This study aimed to develop a heat-stable liposomal vitamin C gummy (LVC gummy) using In Situ Soft Sphere Integrated (ISSI) technology with a xyloglucan/trehalose/citric acid cross-linked polymeric matrix. The ISSI system enhanced the thermal, structural, and chemical stabilities of vitamin C during gummy preparation and storage. Characterization by transmission and scanning electron microscopy, FTIR, particle size, and zeta potential analysis confirmed a uniform vesicle formation and stable polymeric coating. The LVC gummies showed desirable physicochemical properties, including optimal dispersion, swelling behavior, and low water activity. Accelerated stability studies demonstrated improved vitamin C retention, while in vitro release testing indicated minimal release under gastric conditions and sustained release in the intestinal phase compared to conventional gummies. Overall, this approach offers a robust and consumer-acceptable delivery system for vitamin C, providing a practical solution for enhancing vitamin stability in functional foods and nutraceuticals.