Search Results (95)

Contaminants such as nano-polystyrenes (NPs) and heavy metal cocktail (HMC) have been found to disrupt physiological functions in aquatic organisms. Although HMC and NPs alone induce oxidative stress, their combined effects are not well understood. This study aimed to assess the combined effects of HMC and NPs on the freshwater shrimp (Macrobrachium rosenbergii). Shrimp were divided into seven groups, including the control group, and the experimental groups co-exposed to 0, 50, 100, 150, 200, and 250 µg/L NPs combined with 0.5 mg/L HMC. After 14 days, shrimp were sampled, and their hepatopancreas and muscle tissues were analyzed for oxidative biomarkers, biochemical parameters, and metabolic profiles. Moreover, the bioaccumulation rate of heavy metals was measured. Results showed that co-exposure to NPs and HMC increased superoxide dismutase, glutathione peroxidase, glutathione reductase activities, and malondialdehyde levels, while reducing glutathione and total antioxidant capacity. The integrated biomarker response indicated that co-exposure to HMC and NPs induces oxidative stress. A significant decrease was observed in aspartate aminotransferase, gamma-glutamyl transpeptidase, and alkaline phosphatase activities, glycogen, triglyceride, and total protein levels. However, lactate dehydrogenase activity was significantly increased. Co-exposure to HMC and NPs increased heavy metal bioaccumulation, induced oxidative stress, biochemical changes, and enhanced HMC toxicity in shrimp. Full article

In this study, a global response analysis was performed to explore the mechanism of action of Usnic acid and its synergy with Norfloxacin, a well-known quinolone antibiotic to which MRSA clinical isolates showed resistance (MIC, 500 µg/mL). A microdilution assay, a growth kinetics analysis, a microscopic analysis, and cell-based assays consistently showed that Usnic acid possesses strong anti-staphylococcal activity (MIC, 7.8 µg/mL), causes cell leakage, modulates efflux pump activity, and synergizes with Norfloxacin against the multi-drug-resistant clinical isolate MRSA 2071. Whole-cell proteome profiling using gel-free proteomics-based nano-LC-ESI-QTOF-MS/MS revealed several proteins whose expression was significantly modulated by Usnic acid and Norfloxacin alone or in combination. Usnic acid downregulated the abundance of RNA polymerase subunits (RpoB and RpoC), carbamoyl phosphate synthase large subunit (PyrAB), chaperone (GroEL), and adenylosuccinate synthetase (PurA). Interestingly, proteins found to be upregulated in the presence of Usnic acid and Norfloxacin included oxidative-stress-related proteins such as peroxidase (Tpx), alkyl hydroperoxide reductase (AphC), and general stress protein (UspA). This study clearly shows that Usnic acid affects numerous cellular targets and can potentiate the action of Norfloxacin. Furthermore, an in vivo study showed that UA at low concentrations prevents body weight gain, but changes in other tested toxicological parameters were found to be within normal limits. Thus, UA at low doses appears to be a promising candidate for repurposing old antibiotics through combination therapy against MRSA infections. Full article

g-C₃N₄, a biocompatible material, has prominent applications in biology and is ideal for nano-enzyme studies. Though reported as a peroxidase mimic, its activity remains low. This group combined N,S-doped carbon quantum dots (NS-CQDs) with g-C₃N₄ (7NSC-g), verifying its peroxidase-like activity. Based on this, a ternary composite of Co₃O₄ in different forms and 7NSC-g was developed to enhance peroxidase activity, to design a g-C₃N₄-based composite enzyme. Characterizations determined the composition and morphology. Colorimetry evaluated peroxidase activity, where the simulated enzyme catalyzes blue product formation from the TMB substrate in the presence of H₂O₂. UV-Vis spectrophotometry measured absorbance changes to determine target concentrations. The results show Co₃O₄ doping improves catalytic activity, with larger specific surface area providing more activation sites. The highest activity of g-C₃N₄/NS-CQDs/Co₃O₄ was at 5% floral Co₃O₄, being efficient due to Co₃O₄’s electron-transfer acceleration and hydroxyl-radical mechanism. Under optimal conditions, the composite detected H₂O₂ (10.0–230.0 μM, detection limit of 0.031 μM) and glucose (10.0–650.0 μM, detection limit of 1.024 μM). Full article

Glucose detection is critical in addressing health and medical issues related to irregular blood levels. Colorimetry, a simple, cost-effective, and visually straightforward method, is often employed. Traditional enzymatic detection methods face drawbacks such as high costs, limited stability, and operational challenges. To overcome these, enzyme mimics or artificial nano-enzymes based on inorganic nanomaterials have garnered attention, but their cost and susceptibility to inactivation limit applications. This study presents a ZnFe₂O₄/GQDs nanocomposite as an innovative enzyme mimic, addressing key requirements like low cost, high stability, biocompatibility, and wide operational range. Synthesized using a simple and inexpensive method, the composite benefits from the synergistic interaction between ZnFe₂O₄ nanoparticles and graphene quantum dots (GQDs), resulting in excellent magnetic properties, high surface area, and functional versatility. The material demonstrated remarkable sensitivity with a detection limit of 7.0 μM across a range of 5–500 μM and achieved efficient peroxidase-like activity with Km values of 0.072 and 0.068 mM and Vmax of 4.58 × 10⁻⁸ and 8.29 × 10⁻⁸ M/s for TMB and H₂O₂, respectively. The nanocomposite also exhibited robust recyclability, retaining performance over six reuse cycles. Full article

This study used an embedding technique to prepare microcapsules with tea tree oil as the core material and a composite of β-cyclodextrin and nano-montmorillonite as the wall material. The prepared microcapsules were analyzed for their morphological characteristics, thermal stability, and major components. Additionally, the microcapsules’ effect on the quality of and active substances contained in refrigerated strawberries was investigated. The results revealed that the optimal preparation conditions for the microcapsules were a montmorillonite addition of 2% (m/v), a core-to-wall ratio of 1:12 (m/m), an encapsulation temperature of 70 °C, and an encapsulation time of 90 min. Under these conditions, the microcapsules achieved an encapsulation efficiency of 77.67%. The capsules emitted a noticeable aroma of tea tree oil, and their primary components, specifically terpinen-4-ol, 1,8-cineole, p-cymene, and terpinolene, were consistent with those of tea tree oil. The release rate of the microcapsules at 60 °C and 90 °C was significantly lower than that of liquid tea tree oil (p < 0.05). A suitable treatment with tea tree oil microcapsules preserved the appearance and quality of the strawberries, inhibited spoilage during refrigeration, reduced weight loss, maintained firmness, delayed declines in soluble solid contents and acidity in later storage stages, and enhanced the activity of the superoxide dismutase, catalase, and ascorbate peroxidase. The prepared microcapsules also suppressed increases in anthocyanins and inhibited the further maturation of the stored strawberries. The optimal preservative effect was achieved with the placement of 5.0 g of tea tree oil microcapsules per 1.2 L of storage space. Full article

Impeded by the limited light penetration of photodynamic therapy (PDT) to tissues and the hypoxic environment of solid tumors, the clinical therapeutic efficacy and application are below expectations. In this study, a glutathione (GSH)-responsive nano-photosensitizer, based on the chlorquinaldol (CQD)-loaded iron-containing nanorod composed of meso-tetra (4-carboxyphenyl) porphyrin (TCPP), was prepared to serve as the laser-ignited ferroptosis sensitizer to improve the tumoricidal effect of PDT. In the tumor microenvironment (TME) with elevated GSH levels, therapeutic cargos and ferrous ions are released and are accompanied by the degradation of the nano-photosensitizer and GSH exhaustion. This not only increases liable iron pool (LIP) accumulation by the released ferrous ions but also decreases glutathione peroxidase 4 (GPX4) activity by GSH exhaustion. Simultaneously, GSH exhaustion disrupts intracellular redox homeostasis, heightening NIR light irradiation-triggered photosensitive oxidative stress. Moreover, the released CQD elevates the level of intracellular reactive oxygen species (ROS), enabling the nanorods to gain an oxygen radical generation ability and enhancing the photosensitive oxidative therapeutic efficacy. Strikingly, CQD exacerbates the downregulation of GPX4 expression to promote the accumulation of lipid peroxides. Therefore, we herald a new paradigm for synergistically potentiating PDT based on the “all-in-one” nano-photosensitizer through the multi-pronged upregulation of ferroptosis sensitivity. Full article

The extensive utilization of nano-zero-valent iron (nZVI) and its engineered derivatives has prompted significant environmental concerns, particularly regarding their phytotoxicological impacts, which remain inadequately characterized. This investigation systematically evaluated the phytotoxicological responses induced by nZVI, Chlorella vulgaris biochar (BC), and Chlorella vulgaris biochar loaded with nano-zero-valent iron (BC/nZVI) on mung bean seed germination and subsequent seedling development. The experimental data revealed that both the nZVI and BC/nZVI treatments significantly suppressed the germination indices, including germination rate, radicle and plumule elongation, and biomass accumulation, with nZVI demonstrating the most pronounced inhibitory effects. During the vegetative growth phases, nZVI exposure substantially impaired plant morphogenesis, manifested through reduced vertical growth, diminished fresh and dry biomass production, and the onset of premature foliar chlorosis, necrosis, desiccation, and, ultimately, plant mortality. A comparative analysis indicated that the BC/nZVI composites exhibited less severe photosynthetic inhibition relative to pristine nZVI. Biochemical assays demonstrated that nZVI exposure elicited the substantial upregulation in antioxidant enzyme activities, including superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), concomitant with abnormal ferric ion accumulation in root tissues. Notably, BC/nZVI composites demonstrated the partial mitigation of these physiological disturbances. These empirical findings underscore that excessive iron bioavailability from nZVI induces substantial phytotoxicological stress, while BC matrix incorporation provides the partial amelioration of these adverse effects on seedling ontogeny. Full article

Aberrant protein glycosylation is closely associated with a number of biological processes and diseases. However, characterizing the types of post-translational modifications (PTMs) from the complex biological samples is challenging for comprehensive glycoproteomic analysis. The development of high-performance enrichment materials and strategies during the sample pretreatment process is a prerequisite to glycoproteome research. Here in this work, a sulfonate-rich covalent organic framework (COF) called TpPa-(SO₃H)₂ (referred to as SCOF-2) was synthesized using the Schiff base reaction for the identification of glycopeptides. Benefiting from high hydrophilicity and abundant sulfonate affinity, a total of 28 and 16 glycopeptides could be efficiently detected from the standard glycoproteins of horseradish peroxidase (HRP) and immunoglobulin G (IgG) tryptic digest, respectively. Moreover, the as-prepared sulfonate-rich SCOF-2 has an ultralow detection limit (0.01 fmol μL⁻¹), excellent enrichment selectivity (molar ratio HRP:BSA = 1:5000), satisfactory recovery rate (89.1%), high adsorption capacity (150 mg g⁻¹) and good reusability in the individual enrichment. Meanwhile, by using the SCOF-2 adsorbent, 196 and 194 endogenous glycopeptides in the serum of ovarian cancer patients and healthy people among triplicates were successfully enriched and identified, respectively, using combined nanoLC–MS/MS technology. It demonstrated its great application potential in glycoproteomics research and provided a novel insight for the design of affinity materials. Full article

This study aimed to evaluate the effects of the water-soluble fraction of crude oil (WSFO) on Indian carp (Labeo rohita) with and without treatment with zinc oxide nanoparticles (Nano-ZnO). A total of 225 fish were randomly assigned to five groups in triplicate for 21 days. Group I served as the control group. Groups II and III were exposed to 0.5% and 1% untreated WSFO, respectively. Groups IV and V received 5% and 10% WSFO treated with Nano-ZnO, while Groups VI and VII received 5% and 10% WSFO treated without Nano-ZnO. No blood samples were obtained from fish exposed to untreated WSFO, due to increased hemolysis. Exposure to treated WSFO increased creatine phosphokinase, alkaline phosphatase, aspartate aminotransferase, lactate dehydrogenase, and gamma-glutamyl transferase activities, while alanine aminotransferase activity decreased. Although a significant decrease was observed in total protein, globulin, and triglyceride levels, albumin and cholesterol increased. Thiol groups and glutathione peroxidase activity significantly decreased, while superoxide dismutase, catalase, total antioxidant capacity, and malondialdehyde levels increased. The findings showed that exposure to WSFO, whether treated or untreated, induces significant biochemical and oxidative stress responses in Labeo rohita. Although WSFO treated with Nano-ZnO mitigated hemolysis, it was unable to prevent enzyme and antioxidant imbalances, indicating persistent physiological stress. Full article

Nano-hydroxyapatite (n-HAP) and Fe₃O₄ NPs (Fe₃O₄ NPs) offer effective and economical approaches for reducing Cd toxicity, which presents considerable risks to both environmental and human health. We examined the mechanisms through which these NPs mitigate Cd toxicity in bamboo, Pleioblastus pygmaeus. The plants were exposed to Cd (0, 50, 100, and 150 mg L⁻¹) and received foliar sprays of 100 mg L⁻¹ n-HAP, 100 mg L⁻¹ Fe₃O₄ NPs, and a combination of both treatments. The findings indicated that Cd exposure led to oxidized molecules in bamboo, as evidenced by elevated levels of reactive oxygen species (ROS) and lipoperoxidation. Foliar treatments utilizing n-HAP and Fe₃O₄ NPs markedly diminished these effects. H₂O₂, O₂•−, malondialdehyde (MDA), and electrolyte leakage (EL) levels decreased by 56%, 71%, 65%, and 72%, respectively, compared to the controls. The application of n-HAP and Fe₃O₄ NPs significantly enhanced the enzymes, including superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), glutathione reductase (GR), and phenylalanine ammonia-lyase (PAL), with increases observed between 28% and 56%. Furthermore, there was an enhancement in proline accumulation, total phenolic content (TPC), flavonoids (TFC), nitric oxide levels, relative water content (RWC), chlorophyll concentration, and photosynthetic parameters. The combination of n-HAP and Fe₃O₄ NPs was most effective in improving bamboo tolerance to Cd, especially at moderate Cd concentrations of 50 and 80 mg L⁻¹. The results indicate that n-HAP and Fe₃O₄ NPs, particularly in combination, may mitigate Cd toxicity by decreasing Cd uptake, improving antioxidant capacity, and preserving plant water balance. Full article

Microbial contamination is an important factor threatening the safety of Chinese medicine preparations, and microfluidic detection methods have demonstrated excellent advantages in the application of rapid bacterial detection. In our study, a novel optical biosensor was developed for the rapid and sensitive detection of Salmonella in traditional Chinese medicine on a microfluidic chip. Immune gold@platinum nanocatalysts (Au@PtNCs) were utilized for specific bacterial labeling, while magnetic nano-beads (MNBs) with a novel high-gradient magnetic field were employed for the specific capture of bacteria. The immune MNBs, immune Au@PtNCs, and bacterial samples were introduced into a novel passive microfluidic micromixer for full mixing, resulting in the formation of a double-antibody sandwich structure due to antigen–antibody immune reactions. Subsequently, the mixture flowed into the reaction cell, where the MNBs-Salmonella-Au@PtNCs complex was captured by the magnetic field. After washing, hydrogen peroxide-tetramethylbenzidine substrate (H₂O₂-TMB) was added, reacting with the Au@PtNCs peroxidase to produce a blue reaction product. This entire process was automated using a portable device, and Salmonella concentration was analyzed via a phone application. This simple biosensor has good specificity with a detection range of 9 × 10¹–9 × 10⁵ CFU/mL and can detect Salmonella concentrations as low as 90 CFU/mL within 74 min. The average recoveries of the spiked samples ranged from 76.8% to 109.5% Full article

We report the development of amperometric biosensors (ABSs) employing flavocytochrome b₂ (Fcb₂) coupled with nanoparticles (NPs) of noble metals on graphite electrode (GE) surfaces. Each NPs/GE configuration was evaluated for its ability to decompose hydrogen peroxide (H₂O₂), mimicking peroxidase (PO) activity. The most effective nanoPO (nPO) was selected for developing ABSs targeting L-lactate. Consequently, several Fcb₂/nPO-based ABSs with enhanced sensitivity to L-lactate were developed, demonstrating mediated ET between Fcb₂ and the GE surface. The positive effect of noble metal NPs on Fcb₂-based sensor sensitivity may be explained by the synergy between their dual roles as both PO mimetics and electron transfer mediators. Furthermore, our findings provide preliminary data that may prompt a re-evaluation of the mechanism of L-lactate oxidation in Fcb₂-mediated catalysis. Previously, it was believed that L-lactate oxidation via Fcb₂ catalysis did not produce H₂O₂, unlike catalysis via L-lactate oxidase. Our initial research revealed that the inclusion of nPO in Fcb₂-based ABSs significantly increased their sensitivity. Employing other PO mimetics in ABSs for L-lactate yielded similar results, reinforcing our hypothesis that trace amounts of H₂O₂ may be generated as a transient intermediate in this reaction. The presence of nPO enhances the L-lactate oxidation rate through H₂O₂ utilization, leading to signal amplification and heightened bioelectrode sensitivity. The proposed ABSs have been successfully tested on blood serum and fermented food samples, showing their promise for L-lactate monitoring in medicine and the food industry. Full article

Selenium was recognized as a non-toxic element in the second half of the 20th century. Since then, the positive impact of selenium on the functioning of the human body has been noticed. It has been shown that low levels of selenium in the body are significantly associated with a higher risk of developing cancer. Selenium acts as an antioxidant and inhibits the proliferation of cancer cells. It has been shown that selenium supplementation may contribute to reducing the risk of DNA mutations and carcinogenesis. Nanomedicine has become very helpful in both the diagnosis and treatment of cancer. Due to its anticancer properties, selenium is used in nanotechnology as selenium nanoparticles. Full article

Vase life directly affects the ornamental value of cut flowers, and extending vase life has been a research focus in the floriculture industry. The antioxidant and antimicrobial properties of Nano-Se provide a new direction to extend the life of cut-flower vase life. In order to explore the postharvest quality of Nano-Se on cut-flower roses, this study treated cut-flower roses with different concentrations of Nano-Se (200, 400, and 600 mM) using a commercially available preservative solution as a base solution. The results showed that appropriate concentrations of Nano-Se significantly increased the vase life of cut-flower roses and helped to maintain high petal moisture content. Nano-Se at concentrations of 200, 400, and 600 mM extended the vase life of cut roses by 4.3, 5.7, and 3.7 d, respectively. As the vase period extended, the Nano-Se treatment group effectively delayed the decline in antioxidant enzyme activities such as peroxidase (POD) and catalase (CAT), maintained the soluble sugar (SS) and soluble protein (SP) contents in the cut roses, and inhibited the production of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂), reducing their accumulation. A correlation analysis of the physiological indexes of cut roses showed that vase life was positively correlated with POD and CAT activities, SS and SP contents, and total phenolic acid content and negatively correlated with MDA and H₂O₂ contents. This study provides a solid theoretical basis for the diversification of preservatives and the development of new preservatives for fresh-cut roses, which is expected to provide significant economic benefits. Full article

Much is unknown about the positive effect of plant growth regulators, such as brassinosteroids, on high-temperature stress tolerance in pepper plants. This study aimed to reveal the effect of exogenous brassinosteroids (BRs) on high-temperature-stressed bell peppers by foliar application. BR treatments (1 µM), in both bulk (Br) and nano-encapsulated (N-Br) forms, were applied to pepper plants subjected to high-temperature stress (35 °C). The results indicated an increase in plant biomass, number of fruits, and relative water content and a significantly lower flower abscission in response to Br and N-Br under high temperatures. Br and N-Br applications at high temperatures resulted in the lowest leaf water potential. Br and N-Br, especially N-Br, were more effective than Br in the upregulation of the antioxidant enzyme activity, such as catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), and the overall antioxidant capacity of heat-stressed plants. MDA and electrolyte leakage significantly declined as a result of BR application and the proline content of the leaves was significantly higher in Br and N-Br treatments at high temperatures. Further analysis of the data pointed to SOD, DPPH, proline, RWC, and leaf water potential in pepper leaves as the most affected traits in response to brassinosteroid application under high temperature. Glucose and fructose levels also increased under high temperature, and only N-Br administration showed a significant effect on reducing the sugar levels. At high temperatures, the ratio of saturated to unsaturated fatty acids was greatest when neither Br nor N-Br was present. N-Br could reduce this ratio effectively. Conclusively, the overall performance of bell pepper improved in response to both types of BR application with no significant discrimination being found to prioritize the encapsulated form of BR application. Full article