Search Results (1,179)

Alopecia areata (AA) is an autoimmune-mediated nonscarring alopecia with limited therapeutic options and frequent relapses. Exosomes, nanosized extracellular vesicles secreted by various cell types, have recently emerged as potential regenerative and immunomodulatory therapies. The aim of the study is to review the clinical and preclinical evidence regarding the efficacy and safety of EV-based therapies for alopecia areata. a systematic search of PubMed, Embase, Web of Science, and Cochrane Library was performed from 2020 to 2 October 2025. Inclusion criteria were original studies (clinical, preclinical, in vivo, in vitro) investigating exosome-derived interventions for AA. Outcomes of interest were hair regrowth, immune modulation, follicular regeneration, and safety. A total of 499 records were retrieved from electronic database searches. After deduplication and application of the inclusion/exclusion criteria, 40 studies met the eligibility criteria for the review. Of these, two were clinical studies (one retrospective cohort, one case report), while the remainder comprised five animal (in vivo) studies, six in vitro studies, and sixteen mixed translational studies (in vitro/in vivo ± clinical). Experimental studies reported hair coverage improvements of 50–99% and, in one instance, 30% regrowth in totalis and 16% in partialis, with nearly complete regrowth in incipient alopecia. Clinical reports noted density increases of 9–31 hairs per cm² (e.g., from 121.7 to 146.6 hairs/cm², p < 0.001) and improvements in hair count, length, and thickness. Several studies detailed activation of the Wnt/β-catenin pathway along with enhanced dermal papilla and hair follicle stem cell function, as well as anti-inflammatory effects. Reported safety profiles were favorable; when adverse events occurred, they were limited to mild, transient local reactions with no severe systemic issues. EV-based therapy is a novel and biologically plausible approach for AA, but robust randomized controlled trials (RCTs) are lacking. Standardization of small EV sources, doses, and delivery methods is essential before clinical translation. Full article

Phenolic aerogel holds great promise for applications in thermal protection against ablation, and constructing inorganic–organic hybrid networks is an effective strategy to enhance its oxidation and ablation resistance. This study introduces a stepwise hybridization strategy for the preparation of SiO₂–ZrO₂–phenolic resin aerogels (SZPA). First, nano-silica sol and nanometer-scale zirconia were physically blended to form a uniformly dispersed mixture. Subsequently, the modified silica was incorporated into a phenolic resin solution to construct a three-dimensional hybrid silica–phenolic network framework. Nano-sized zirconia was then uniformly dispersed within the matrix as a physical reinforcing phase through high-shear dispersion. Finally, the SZPA with a hierarchical nanoporous structure was obtained via ambient-pressure drying. Owing to its unique hybrid network structure, the aerogel exhibits markedly improved properties: the thermal conductivity is as low as 0.0419–0.0431 W/(m·K) (a reduction of approximately 24%), and the specific surface area is as high as 190–232 m²/g (an increase of approximately 83%). Meanwhile, the inorganic network considerably enhances the residual mass at elevated temperatures, as well as the oxidation resistance and thermal stability of the matrix. Among the tested materials, the SZPA-4 exhibited outstanding thermal insulation capability at high temperatures; its back surface temperature reached only 74.4 °C after 600 s of exposure to a 1200 °C butane flame. This study provides a feasible route for the preparation of high-performance phenolic-based composite aerogels for aerospace thermal protection systems, thereby expanding their potential applications in extreme thermal environments. Full article

This study synthesizes novel photosensitizer calcination betaine hydrochloride carbon dots (CBCDs) to address the critical challenge of Enterococcus faecalis (E. faecalis) biofilms, a major cause of root canal treatment failure. To this end, this study investigates the effective elimination via reactive oxygen species (ROS) mediated by these CBCDs. CBCDs were prepared by calcining betaine hydrochloride and rigorously characterized for their structural and chemical properties using transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Their optical characteristics were also thoroughly analyzed through UV-Vis and fluorescence spectroscopy. The RNO-ID assay was performed to explicitly confirm ROS production, particularly verifying significant singlet oxygen (¹O₂) generation. Bactericidal efficacy of the CBCDs was comprehensively evaluated against planktonic E. faecalis and its formed biofilms. Live/dead staining was subsequently performed to observe their state after treatment. As a result, TEM confirmed nanosized CBCDs, and FTIR/XPS analyses identified crucial functional groups. Colony Forming Unit (CFU) assays revealed a dose-dependent reduction in E. faecalis viability, achieving complete eradication at 200 mg/L under light irradiation. Complete cell death and inactivation of the formed biofilms with increasing CBCD concentrations were also strongly evidenced by red fluorescence. The obtained results underscore CBCDs as highly effective photodynamic agents for the robust elimination of E. faecalis biofilms, offering a promising new strategy to combat persistent oral infections. Full article

Some European Heavy Duty (HD) vehicle manufacturers have adopted Open Crankcase Ventilation (OCV) systems to improve reliability and performance. The emission compliance of HD vehicles both during certification and In-Service Conformity (ISC) testing need to also account for the crankcase ventilation. Despite that, the contribution of crankcase emissions to the overall emissions profile of modern trucks remains underexplored. This study experimentally characterizes the crankcase emissions of a Euro VI Step E HD truck equipped with an OCV system under controlled conditions on a chassis dynamometer. Emissions were measured over the World Harmonized Vehicle Cycle (WHVC) and an ISC-compliant driving cycle at two test cell temperatures. The results indicate that crankcase emissions account for up to 4% and 8% of the current regulatory limits for nitrogen oxides (NO_x) and 23 nm solid particle number (SPN₂₃), respectively. The tightening of NO_x limits under Euro 7 regulations would increase these contributions to approximately 11%. SPN₁₀ crankcase emissions were found to be on the order of 10¹¹ (11% of the Euro 7 limit). Real-time SPN₁₀ and SPN₂₃ measurements revealed that the fraction of nanosized particles increases significantly during cold start, suggesting increased oil combustion within the cylinder. These findings highlight the need to refine crankcase emissions measurement procedures within regulatory frameworks. A systematic investigation of measurement setups and ageing effects, taking into account variations in OCV system designs and piston ring wear, is essential to determine whether characterization during certification is sufficient or if ISC testing throughout the vehicle’s useful life will be required. Full article

Developing sustainable and eco-friendly approaches to plant propagation, development, and protection is a common goal for the scientific community. Plant cell culturing enables us to obtain plant clones and produce biomolecules under controlled conditions. The same principle can be applied to the harvesting of extracellular vesicles (EVs). These nanosized structures are key players in cell communication and stress response by carrying, protecting, and delivering important biomolecules. Raising interest in the scientific community, EVs have been successfully tested as nanocarriers for therapeutics and biotechnology. However, despite their potential, there remains a gap in research on scalable, reliable sources for EV production. Our goals were to optimize EV production and isolation from induced poplar callus cell lines (Populus tremula × P. alba) and load these with RNA to validate their functionality as nanocarriers. We were able to isolate 2.5 × 10¹⁰ EVs/g, highlighting the potential for these lines to be mass-produced. Furthermore, RNA loaded into EVs through electroporation was internalized into Botrytis cinerea hyphae, reassuring their potential in protecting and delivering cargo. Our findings contribute to EV characterization and demonstrate that RNA delivery through EV transport could be a safe and effective method for future EV-based technologies in plant protection. Full article

This study systematically investigated the electrorheological (ER) behavior of four aqueous smectite clay dispersions—fluorinated hectorite (Ht-F), stevensite (Stv), hectorite (Ht), and saponite (Sap)—with emphasis on transparency, rheological responses, and interparticle interactions. Optical observations revealed that the transparency of the aqueous dispersions followed the order Ht-F > Stv > Ht > Sap, which corresponded well to the finer network structures previously observed in Cryo-SEM images. Whereas micrometer-sized poly(methyl methacrylate) (PMMA) dispersions exhibited electrically induced rapid and reversible separation (ERS) due to sedimentation, the nanosized clays, which do not settle, developed ER effects through field-driven flocculation and subsequent network formation. Under low-frequency AC fields, Ht-F showed highly reversible responses similar to Stv, whereas Sap exhibited irreversible stress increases, accompanied by suspected ion release under the field. Dynamic rheological measurements showed that application of electric fields enhanced the loss modulus (G″) more prominently than the storage modulus (G′), clearly indicating a strengthening of viscous behavior. Derjaguin–Landau–Verwey–Overbeek theory (DLVO) potential analysis yielded a barrier-height sequence (Stv < Ht-F < Ht < Sap) that directly paralleled the order of ER responsiveness. These results demonstrate that the ER hierarchy of aqueous smectites can be rationalized by DLVO interactions and provide design guidelines for environmentally compatible ER fluids. Full article

Background: Paclitaxel (PTX), a taxane chemotherapy drug, is widely regarded as one of the most potent and clinically effective treatments for advanced and resistant cancers. However, paclitaxel’s poor bioavailability is attributed to its unfavorable physicochemical properties, including low solubility and permeability. Nanosizing and multidrug combination strategies have emerged as key approaches to enhance the formulation of such compounds. Pterostilbene (PTE), a polyphenolic compound, possesses extensive anti-cancer properties and favorable hydrogen bond formation sites. In this study, PTE was employed to co-assemble with PTX to improve its physicochemical properties and enhance therapeutic efficacy. Methods: Paclitaxel-pterostilbene nanoparticles (PTX-PTE NPs) were characterized by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Results: PTX-PTE nanoparticles significantly improved the water solubility (7fold increase) and cytotoxicity of paclitaxel in tumor cells. The enhanced antitumor efficacy was achieved through P-gp and CDK1 protein downregulation, increased drug accumulation, and cell cycle inhibition. Conclusions: These improvements are attributed to the nanoparticles’ amorphous structure and nanoscale properties. In addition, the combined use of PTX and PTE significantly enhanced the cytotoxicity against human non-small cell lung cancer A549 cells. PTX-PTE nanoparticles show promise for improving drug delivery and overcoming multidrug resistance in A549 cells. Full article

Carbon dioxide reforming of methane is a promising technology to recycle and reduce greenhouse gases (CH₄, CO₂) into valuable chemicals and fuels. The Co-Fe catalysts modified with a small amount of Pt and supported on alumina were designed to be explored in dry reforming (DRM) and combined CO₂-steam reforming (bireforming, BRM) of methane to produce syngas. The catalysts were characterized by physico-chemical methods (i.e., BET, XRD, TEM, SEM, and TPR-H₂). The synthesized catalysts are the X-ray amorphous nanosized materials with particle sizes of less than 30 nm. The processes were carried out using a feed of CH₄/CO₂/H₂O = 1/1/0–0.5 at varying temperature (400–800 °C) at atmospheric pressure and GHSV = 1000 h⁻¹. The combination of Co and Fe in varying ratios with Pt allowed for high activity and selectivity to be maintained. Extents of methane and CO₂ conversion are varied within a range of 79.5–97.5 and 64.2–85.2%, respectively, at 700–800 °C, while the H₂/CO ratio in the resulting syngas ranged from 0.98 to 1.30, depending on the catalyst and feed composition. Stability tests conducted for up to 80 h on stream showed no loss of activity of the 10%Co-Fe-Pt/Al₂O₃ catalysts in BRM. We believe that high activity of the synthesized catalysts occurs due to synergy in the Co-Fe-Pt system. Full article

With the increasing harsh drilling environments encountered more frequently than ever before, developing environmentally benign and multifunctional additives is essential to formulate high performance drilling fluids. Herein, hydrothermal carbon/bentonite composites (HCBCs) were prepared by a hydrothermal carbonization reaction using soluble starch and sodium bentonite as raw materials. A systematic investigation was conducted into the effects of HCBC concentration on the rheological, filtration, and lubricating characteristics of xanthan gum, modified starch, and high-temperature polymer slurries. These properties were evaluated before and after exposure to hot rolling at different temperatures. The hydroxyl radical scavenging properties of HCBC were evaluated. Observation showed plentiful micro- and nano-sized carbon spheres deposited on the bentonite particles, endowing the bentonite with better dispersion. HCBCs could maintain stability of the water-based drilling fluids’ rheological profile, decrease filtration loss, and improve the lubrication with relatively low concentrations. The excellent properties were attributed to the highly efficient scavenging of free radicals and the stabilization of bentonite particle dispersion. Full article

Selenium (Se) nanoparticles have emerged as a vital tool in enhancing plant resilience to multiple stress factors. So, the present study was designed to synthesize nano-Se, evaluate its antibacterial properties, and to investigate the effects of nano-Se at 2, 5, 10, and 15 μM on the growth and physiological responses of barley seedlings under Cd stress. The results showed that nano-Se with an average size of 24.71 nm exhibited strong antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Notably, 5 μM nano-Se reduced Cd concentrations in leaves and roots by 19.46% and 31.07%, respectively, while enhancing root length, shoot/root fresh weight (FW), and dry weight (DW) compared to Cd-stressed plants. Furthermore, exogenous nano-Se significantly increased chlorophyll, protein, amino acid content, and enhanced photosynthetic performance compared to Cd treatment alone. Nano-Se further boosted the activity of antioxidant enzymes and concurrently reduced malondialdehyde (MDA), hydrogen peroxide (H₂O₂), proline, total flavonoids, and total phenols levels. Moreover, nano-Se supplementation under Cd stress promoted the uptake of essential nutrient elements and increased sugar content. Our results collectively suggest that nano-Se application during Cd stress may enhance photosynthesis, promote carbohydrate metabolism, and mitigate oxidative damage, thereby improving barley growth under Cd toxicity. Full article

This study addresses the challenges of osteochondral tissue engineering by developing a hybrid scaffold with intercalated layers of poly(ε-caprolactone) (PCL) in combination with different concentrations of nanosized synthetic smectic clay (Lap) and a hydrogel of chitosan, collagen and demineralized bone powder (DBP). The scaffold design specifically targets the critical junction between subchondral bone and calcified cartilage and utilizes the mechanical strength of PCL/Lap nanocomposites and the bioactivity of the chitosan/collagen/DBP hydrogel to support tissue regeneration. The PCL/Lap nanocomposite, characterized by increased hydrophilicity, improved swelling behavior, and enhanced stiffness, provides a robust scaffold, while the hydrogel layers improve bioactivity and fluid retention. Three-dimensional printing technology was used to fabricate multi-layer scaffold, ensuring interfacial cohesion between the layers. Rheological, morphological, chemical, and mechanical characterizations confirmed the successful integration of the materials and the mechanical suitability for the subchondral environment. Biocompatibility assays demonstrated the non-hemolytic nature of the scaffolds and a favorable trend in cell viability with increasing Lap content. This study presents a novel scaffold design that effectively combines mechanical stability and biological functionality. It fulfills the complex requirements of osteochondral repair and offers a promising platform for future tissue engineering strategies. Full article

This review is an exhaustive analysis of the recent progress in the research of active and biologically active additives/ingredients. Fast-developing innovations during the last 3–5 years are included in every stage of their preparation from various resources, with valorization of the by-products and waste, characterization, arising problems with their applications, and an important role in the production of the advanced, high-performance materials. The two main well-known classes as natural (bio)active additives and nanoscaled active additives are discussed as it concerns, their types, classification, characteristic mode of action, green extraction and preparation, green synthesis, supplementary processing performed to achieve the suitable stability of the systems by micro-/nanoemulsification/encapsulation, complexation, etc., importance of the composition–activity relationships, biological effects, antimicrobial, antifungal, antioxidant potential, controlled/targeting release of (bio)active agents, the mechanisms of action of antimicrobials, antifungal and antioxidants synthesized in vivo or derived from the human diet, analytical methods for BACs characterization, degradation, toxicity concerns, a.s.o. The combinations of the two kinds of active additives (including even natural additives prepared at the nanosized level) are frequently used in research and scale-up production of new materials as important innovative solutions and challenges in various application fields, especially when their synergism appears, as will be detailed in the second part of this review. Full article

The high-Mg-content Al-Mg-Zn-Si alloy, as a novel aluminum alloy, exhibits excellent strength, toughness, and corrosion resistance, demonstrating significant application potential in lightweight structural components for aerospace, weapon systems, rail transportation, and other fields. In this study, friction stir welding was employed to weld the high-Mg-content Al-Mg-Zn-Si alloy. Subsequent aging treatment was applied to establish the relationship between the mechanical properties and microstructural characteristics of the welded joint, aiming to elucidate the strengthening mechanisms of the new alloy and provide insights for achieving high-quality welds. The results indicate that the microhardness profile of the as-welded joint exhibited a “W” shape, with overall low hardness values and minor differences between zones. After the aging treatment, the microhardness increased significantly in the base material (BM), the thermo-mechanically affected zone (TMAZ), and the stir zone (SZ), whereas the heat-affected zone (HAZ) adjacent to the SZ exhibited only a marginal increase, making it the softest region in the aged joint. The yield strength and ultimate tensile strength of the aged joint increased to 327 MPa and 471 MPa, respectively. The enhancement in microhardness and strength after aging treatment was attributed to the precipitation of numerous nano-sized T-phase particles within grains. Interestingly, the tensile samples of the aged joint fractured in the high-hardness SZ instead of the low-hardness HAZ. This fracture behavior was primarily attributed to continuous grain boundary precipitates, which reduced intergranular cohesion. In contrast, the elongated grain structure in the HAZ more effectively resisted intergranular crack propagation compared to the equiaxed grains in the SZ. Full article

In this work, the effect of aqueous dispersions of graphene oxide (GO) and nanosized graphene oxide (nGO) on the enzymatic polymerization of polyaniline (PANI) was studied. The enzymatic polymerization of PANI was carried out in aqueous medium using toluenesulfonic acid (TSA) as the dopant, horseradish peroxidase (HRP) as the catalyst, and hydrogen peroxide (H₂O₂) as the oxidant, using 1.0, 2.5, and 5.0 wt% of GO and nGO. The morphology of PANI-GO/nGO composites was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Further characterization was performed by thermogravimetric analysis (TGA) and spectroscopic techniques such as ultraviolet–visible (UV–Vis), Fourier-transform infrared (FTIR), Raman and X-ray photoelectronics (XPS). SEM images showed that during enzymatic polymerization, PANI completely covers the GO/nGO sheets. Furthermore, physicochemical results confirmed the production of a hybrid PANI-GO/nGO material with Van der Waals-type interactions between the oxygen-based functional groups of GO and the secondary amino bond (-NH-) of PANI. Also, cyclic voltammetry experiments were carried out in situ during the polymerization of PANI-GO/nGO films. The electrochemical response of PANI-GO/nGO composites reflects two broad oxidation peaks around 300 mV and 500 mV during anodic scanning, with reversible oxidation during cathodic scanning. Classical molecular dynamics simulations were used to understand the mechanism of the composite film’s growth. Full article

The ubiquitous environmental pollution with micro- and nano-sized plastic particles (MNPs) is a current and significant problem today. At the same time, lung cancer is responsible for the largest number of cancer-related deaths worldwide. Many research groups have investigated the relationship between lung cancer development and exposure to MNPs in recent years. Studies have demonstrated that these particles could enter the respiratory system in a variety of ways—both directly through inhaled air and through the bloodstream, and through internalization in the intestines and other digestive organs. Data regarding the possibility of their aggregation in the respiratory system, thyroid gland, and brain are also concerning, as the harmful effects of MNPs have been proven to depend on their concentration and exposure time. The primary response of cells to plastic particles is an increase in oxidative stress. This is generated both by the cell itself (especially macrophages) and induced by damage caused by mechanical damage to cellular organelles by MNPs. The consequences of MNP exposure can include metabolic disturbances, DNA damage, and mutations, ultimately inducing neoplastic transformation in healthy cells. This can lead to changes in tissue architecture and increase their susceptibility to other pathogens, such as pathogenic microorganisms or heavy metals. These, in turn, can be internalized along with MNPs, forming a corona surrounding them. Full article