Bio-photoelectrochemical degradation, and photocatalysis process by the fabrication of copper oxide/zinc cadmium sulfide heterojunction nanocomposites: Mechanism, microbial community and antifungal analysis

Catalytic reduction of toxic dyes over nickel oxide nanoparticles supported on CMK-3 catalyst

In the current paper, a NiO nanoparticles-loaded mesoporous carbon (CMK-3) catalyst, denoted as NiO/CMK-3, has been successfully synthesized using a facile strategy. The as-prepared material has been characterized through XRD, Raman spectroscopy, low-temperature N2 physisorption measurements, FTIR, FE-SEM, TEM, and XPS. The as-fabricated NiO/CMK-3 catalyst manifested a superior activity in the NaBH4-assisted reduction of methylene blue (MB) dye to its colorless leuco form. Remarkably, over 99% of 25 mg L-1 MB was reduced by 7.5 mM/L NaBH4 using 0.1 g L-1 NiO/CMK-3 within 3 min at room temperature. Furthermore, the kinetics study confirmed the appropriateness of the pseudo-first-order kinetic model for elucidating the kinetics of MB reduction by the catalyst. Importantly, the NiO/CMK-3 catalyst maintained almost constant catalytic activity even after 5 times of reuse in MB reduction, demonstrating its superior stability and reusable ability. So, NiO/CMK-5 appears as a promising heterogeneous catalyst for the effective remediation of dye-containing wastewater.

Nanocomposites against Pseudomonas aeruginosa biofilms: Recent advances, challenges, and future prospects

Pseudomonas aeruginosa is an opportunistic bacterial pathogen that causes life-threatening and persistent infections in immunocompromised patients. It is the culprit behind a variety of hospital-acquired infections owing to its multiple tolerance mechanisms against antibiotics and disinfectants. Biofilms are sessile microbial aggregates that are formed as a result of the cooperation and competition between microbial cells encased in a self-produced matrix comprised of extracellular polymeric constituents that trigger surface adhesion and microbial aggregation. Bacteria in biofilms exhibit unique features that are quite different from planktonic bacteria, such as high resistance to antibacterial agents and host immunity. Biofilms of P. aeruginosa are difficult to eradicate due to intrinsic, acquired, and adaptive resistance mechanisms. Consequently, innovative approaches to combat biofilms are the focus of the current research. Nanocomposites, composed of two or more different types of nanoparticles, have diverse therapeutic applications owing to their unique physicochemical properties. They are emerging multifunctional nanoformulations that combine the desired features of the different elements to obtain the highest functionality. This review assesses the recent advances of nanocomposites, including metal-, metal oxide-, polymer-, carbon-, hydrogel/cryogel-, and metal organic framework-based nanocomposites for the eradication of P. aeruginosa biofilms. The characteristics and virulence mechanisms of P. aeruginosa biofilms, as well as their devastating impact and economic burden are discussed. Future research addressing the potential use of nanocomposites as innovative anti-biofilm agents is emphasized. Utilization of nanocomposites safely and effectively should be further strengthened to confirm the safety aspects of their application.

Microwave-assisted aqueous two-phase extraction of polysaccharides from Hippophae rhamnoide L.: Modeling, characterization and hypoglycemic activity

Natural polysaccharides are concerned for their high biological activity and low toxicity. Two kinds of polysaccharides were extracted from Hippophae rhamnoide L. by microwave-assisted aqueous two-phase system. Under the optimal conditions predicted by RSM model (K2HPO4/ethanol (18.93 %/28.29 %), liquid to material ratio 77 mL/g, power 625 W and temperature 61 °C), the yield of total polysaccharides reached 35.91 ± 0.76 %. Moreover, the polysaccharides extraction was well fitted to the Weibull model. After purification by Sepharose-6B, the polysaccharides from top phase (PHTP, purity of 81.44 ± 1.25 %) and bottom phase (PHBP, purity of 88.85 ± 1.40 %) were obtained. GC, FT-IR, methylation and NMR analyses confirmed the backbone of PHTP was composed of a repeated unit →4)-β-D-Glcp-(1 → 2)-α-L-Rhap-(1 → 4)-β-D-Galp-(1 → 4)-α-D-GalAp-(1 → 3)-α-L-Araf-(1 → 3)-α-D-Manp-(1→, while the repeated unit in PHBP was →3)-α-L-Araf-(1 → 2)-α-L-Rhap-(1 → 4)-β-D-Glcp-(1 → 3)-α-D-Manp-(1 → 4)-β-D-Galp-(1 → 4)-α-D-GalAp-(1→. Compared with PHTP (6.46 × 106 g/mol), PHBP with relatively low molecular weight (8.2 × 105 g/mol) exhibited the smaller particle size, better water-solubility, thermal and rheological property, stronger anti-glycosylation and α-amylase inhibitory effects. Moreover, PHTP and PHBP displayed a reversible inhibition on α-amylase in a competitive manner. This study provides a high-efficient and eco-friendly method for polysaccharides extraction, and lays a foundation for sea buckthorn polysaccharides as potential therapeutic agents in preventing and ameliorating diabetes.

Design, synthesis and biological evaluation of new 1,ω-Bis-(5-alkyl-3-tosyl-1,3,4,2-triazaphospholino)alkanes as in vitro α-amylase and lipase inhibitors

A series of new 1,ω-bis-(5-alkyl-3-tosyl-1,3,4,2-triazaphospholino)alkanes 2 and 3 were obtained in excellent yields by the condensation of 1,ω-bis-(1-tosylamidrazone)alkanes 1 with two equivalent molars of Lawesson's Reagent (LR) and trisdimethylaminophosphine, respectively. All synthesized compounds were characterized by various spectroscopic techniques including IR, 1H NMR, 13C NMR and 31P NMR and elemental analysis. The newly synthesized compounds were evaluated against key enzymes related to diabetes and obesity such as α-amylase and lipase. This study showed that the compounds 3a and 2b are an excellent inhibitor of α-amylase (with IC50 = 18.8 mM) and lipase (with IC50 = 19 mM) respectively, as compared with standard, orlistat (IC50 = 22 mM). Among this series, compounds 3a and 2b with the CH3 or C2H5 group at position 6 were identified as the most potent inhibitors against α-amylase, and lipase enzymes. The remaining compounds were found to be moderately active. Further, molecular docking simulation studies were done to identify the interactions and binding mode of synthesized analogs at binding site of α-amylase and lipase enzymes.

Cube-shaped Cobalt-doped zinc oxide nanoparticles with increased visible-light-driven photocatalytic activity achieved by green co-precipitation synthesis

From the perspective of environmental protection, the highly efficient degradation of antibiotics and organic dyes in wastewater needs to be tackled as soon as possible. In this study, an ecofriendly and green cube-shaped cobalt-doped zinc oxide nanoparticles (Co-ZnO NPs) photocatalyst using Pterocladia Capillacea (P. Capillacea) water extract loaded with 5, 10, and 15% cobalt ions were formed via co-precipitation process to degrade antibiotics. The prepared Co-ZnO NPs were tested as a photocatalyst for the photodegradation of ciprofloxacin (CIPF) in the presence of a visible LED-light source. Co-ZnO NPs have been obtained through the co-precipitation method in the presence of P. Capillacea extract as a green capping agent and reducing agent, for the first time. Several characterization techniques including FTIR, XRD, BET, XPS, TEM, EDX, SEM, TGA and DRS UV-Vis spectroscopy were applied to study the prepared Co-ZnO NPs. XRD results suggested that the average size of these NPs ranged between 42.82 and 46.02 nm with a hexagonal wurtzite structure. Tauc plot shows that the optical energy bandgap of ZnO NPs (3.19 eV) gradually decreases to 2.92 eV by Co doping. Examinations showed that 5% Co-ZnO NPs was the highest efficient catalyst for the CIPF photodegradation when compared with ZnO NPs and other 10 and 15% Co-ZnO NPs. A 10 mg/L solution of CIPF was photo-degraded (100%) within the first 15 min irradiation. The kinetics showed that the first-order model is suitable for displaying the rate of reaction and amount of CIPF elimination with R2 = 0.952. Moreover, central composite design optimization of the 5% Co-doped ZnO NPs was also investigated.

Current Overview of Metal Nanoparticles' Synthesis, Characterization, and Biomedical Applications, with a Focus on Silver and Gold Nanoparticles

Metal nanoparticles (NPs) have garnered considerable attention, due to their unique physicochemical properties, that render them promising candidates for various applications in medicine and industry. This article offers a comprehensive overview of the most recent advancements in the manufacturing, characterization, and biomedical utilization of metal NPs, with a primary focus on silver and gold NPs. Their potential as effective anticancer, anti-inflammatory, and antimicrobial agents, drug delivery systems, and imaging agents in the diagnosis and treatment of a variety of disorders is reviewed. Moreover, their translation to therapeutic settings, and the issue of their inclusion in clinical trials, are assessed in light of over 30 clinical investigations that concentrate on administering either silver or gold NPs in conditions ranging from nosocomial infections to different types of cancers. This paper aims not only to examine the biocompatibility of nanomaterials but also to emphasize potential challenges that may limit their safe integration into healthcare practices. More than 100 nanomedicines are currently on the market, which justifies ongoing study into the use of nanomaterials in medicine. Overall, the present review aims to highlight the potential of silver and gold NPs as innovative and effective therapeutics in the field of biomedicine, citing some of their most relevant current applications.

Surface activity, kinetics, thermodynamics and comparative study of adsorption of selected cationic and anionic dyes onto H3PO4-functionalized bagasse from aqueous stream

The discharge of dyes into the water body creates toxicity to aquatic organisms because of their aromatic structure and difficult degradation. So, the treatment of dye-contaminated wastewater is required before releasing it. In the present study, thermally treated (600 °C) and H3PO4 (55%)-functionalized bagasse, henceforth called thermochemically activated bagasse (TCAB), was synthesized as potential adsorbent for the effective removal of selected cationic and anionic dyes from their aqueous stream. TCAB characterization was done employing FT-IR, SEM, XRD, zeta potential, BET, and PZC techniques. The comparative study shows that the relative adsorption on TCAB followed the sequence, methyl red (185 mg/g) > safranin (178 mg/g) > congo red (146 mg/g) > brilliant green (139 mg/g) > malachite green (130 mg/g) > bromocresol green (94 mg/g). The adsorption efficiency was investigated concerning the effect of change in TCAB dose (0.05-0.3 g/100 mL), initial dye concentration (20-200 mg/L), pH (4.0-10.0), ionic strength (0.1-0.5 M KCl), urea concentration (0.1-0.5 M) and temperature (25-45 °C). The representative adsorption isotherms belong to typical L-type. The time-dependent dye removal was best explained by the pseudo-second-order (PSO) kinetic model (R2 = 0.9859-0.9991), while equilibrium data were best explained by the Freundlich model (R2 = 0.9881-0.9961). Thermodynamic study showed the spontaneous (ΔG0 <0) and exothermic nature (ΔH0 <0) of the adsorption of different cationic and anionic dyes. The cyclic adsorption ability of TCAB for different dyes was checked up to three cycles (185 to 168 mg/L for MR, 178 to 165 mg/L for SF, 146 to 130 mg/L for CR, 139 to 127 mg/L for BG, 130 to 114 mg/L for MG and 94 to 80 mg/L for BCG), and no significant decrease in the adsorption capacity was noticed. So, the present study provides valuable insights into the adsorption of cationic and anionic dyes onto H3PO4-functionalized bagasse. Addressing the adsorptive aspects enhances the clarity, reliability and applicability of the study's findings and contributes to its overall scientific impact.

Photocatalytic and Enhanced Biological Activities of Schiff Base Capped Fluorescent CdS Nanoparticles

In the present work, biocompatible CdS nanoparticles were synthesized using Schiff base ligand, 3-((2-(-(1-(2hydroxyphenyl)ethylidene)amino)ethyl)imino)-2-pentone, by a simple ultrasonic irradiation method. The structural, morphological, and optical properties were studied using XRD, SEM, TEM, UV-visible absorption, and photoluminescence (PL) spectra. The quantum confinement effect of the Schiff base capped CdS nanoparticles was confirmed by using UV-visible and PL spectrum analysis. This CdS nanoparticles were an effective photocatalyst for degrading rhodamine 6G and methylene blue with a 70% and 98% degradation capacity, respectively. Furthermore, the disc-diffusion method demonstrated that CdS nanoparticles inhibit G-positive bacteria and G-negative bacteria more effectively. These Schiff base capped CdS nanoparticles were taken for an in-vitro experiment with HeLa cells to exhibit the possibility of providing optical probes in biological applications and observed under a fluorescence microscope. In addition, MTT cell viability assays were carried out to investigate the cytotoxicity for 24 h. As a result of this study, 2.5 µg/ml doses of CdS nanoparticles are suitable for imaging and are effective in destroying HeLa cells. The present study suggests that the synthesized Schiff base capped CdS nanoparticles could be a potential photocatalyst, antibacterial agent, and biocompatible nanoparticle for bioimaging applications.

Zinc Oxide Quantum Dots May Provide a Novel Potential Treatment for Antibiotic-Resistant Streptococcus agalactiae in Lama glama

Streptococcus agalactiae is a significant pathogen that can affect both human beings and animals. The extensive current use of antibiotics has resulted in antibiotic resistance. In our previous research, we found that zinc oxide quantum dots (ZnO QDs) had inhibitory effects on antibiotic-resistant microorganisms. In this study, a strain of Streptococcus agalactiaeWJYT1 with a broad antibiotic-resistant spectrum was isolated and identified from Lama glama at Sichuan Agricultural University Teaching Animal Hospital. The genome for the resistance and virulence genes was analyzed. Additionally, the antibacterial effects and anti-virulence mechanism of ZnO QDs for S. agalactiaeWJYT1 were investigated. The results showed that the genome of S. agalactiaeWJYT1 is 1,943,955 bp, containing 22 resistance genes and 95 virulence genes. ZnO QDs have a good antibacterial effect against S. agalactiaeWJYT1 by reducing bacterial growth and decreasing the expression of virulence genes, including bibA, hylB, sip, and cip, which provides a novel potential treatment for S. agalactiae.

Applying MCM-48 mesoporous material, equilibrium, isotherm, and mechanism for the effective adsorption of 4-nitroaniline from wastewater

In this work, the MCM-48 mesoporous material was prepared and characterized to apply it as an active adsorbent for the adsorption of 4-nitroaniline (4-Nitrobenzenamine) from wastewater. The MCM-48 characterizations were specified by implementing various techniques such as; scanning electron microscopy (SEM), Energy dispersive X-ray analysis (EDAX), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area, pore size distribution (PSD), and Fourier transform infrared (FTIR). The batch adsorption results showed that the MCM-48 was very active for the 4-nitroaniline adsorption from wastewater. The adsorption equilibrium results were analyzed by applying isotherms like Langmuir, Freundlich, and Temkin. The maximum experimental uptake according to type I Langmuir adsorption was found to be 90 mg g^-1 approximately. The Langmuir model with determination coefficient R² = 0.9965 is superior than the Freundlich model R² = 0.99628 and Temkin model R² = 0.9834. The kinetic adsorption was investigated according to pseudo 1st order, pseudo 2nd order, and Intraparticle diffusion model. The kinetic results demonstrated that the regression coefficients are so high R² = 0.9949, that mean the pseudo 2nd order hypothesis for the adsorption mechanism process appears to be well-supported. The findings of adsorption isotherms and kinetics studies indicate the adsorption mechanism is a chemisorption and physical adsorption process.

Efficient photocatalytic degradation of organic pollutants over TiO2 nanoparticles modified with nitrogen and MoS2 under visible light irradiation

Investigate the use of visible light to improve photocatalytic degradation of organic pollutants in wastewater. Nitrogen-doped titania and molybdenum sulfide nanocomposites (NTM NCs) with different weight ratios of MoS₂ (1, 2, and 3 wt.%) synthesized by a solid state method applied to the photodegradation of methylene blue(MB) under visible light irradiation. The synthesized NTM composites were characterized by SEM, TEM, XRD, FT-IR, UV-Vis, DRS and PL spectroscopy. The results showed enhanced activity of NTM hybrid nanocrystals in oxidizing MB in water under visible light irradiation compared to pure TiO₂. The photocatalytic performance of NTM samples increased with MoS₂ content. The results show that the photodegradation efficiency of the TiO₂ compound improved from 13 to 82% in the presence of N-TiO₂ and to 99% in the presence of MoS₂ containing N-TiO₂, which is 7.61 times higher than that of TiO₂. Optical characterization results show enhanced nanocomposite absorption in the visible region with long lifetimes between e/h+ at optimal N-TiO₂/MoS₂ (NTM₂) ratio. Reusable experiments indicated that the prepared NTM NCs photocatalysts were stable during MB photodegradation and had practical applications for environmental remediation.

An ultra-small fluorescence zero-valent iron nanoclusters selectively kill gram-positive bacteria by promoting reactive oxygen species generation

A list of the most dangerous bacteria that are multiple-drug resistance has been published by WHO, among which are various Gram-positive bacteria related with serious healthcare and community-associated infection. An effort is called for developing new strategies to combat the resistance, and nanomaterial-based approaches provide an ideal potential to mitigate the antimicrobial resistance as an alternative to antibiotics. Nanoscale zero-valent iron particles exhibited a good antimicrobial activity by triggering Fenton reaction, however, no zero-valent iron nanoclusters are developed as antimicrobial medical materials. In this work, a novel ultra-small zero-valent iron nanoclusters (usZVIN) was synthesized by one-step reduction in aqueous solutions, which exhibited bright red fluorescence at 616 nm. Interestingly, the usZVIN displayed an excellent selectively antibacterial activity against Gram-positive bacteria, and little effects on Gram-negative bacteria. The killing efficiency of usZVIN against S. aureus can reach 100 % with a concentration of 40 μg mL^-1 after 1 h incubation, whereas there is no killing effect of usZVIN against E.coli even with a concentration of 900 μg mL^-1 for 4 h. The antimicrobial mechanism of usZVIN was demonstrated to be the intracellular reactive oxygen species (ROS) production triggered by usZVIN due to its excellent peroxidase-like activity. Collectively, our findings suggested that usZVIN is a good medical-material candidate for fighting against Gram-positive bacterial infections, especially when we need leave beneficial Gram-negative bacteria intact.

Exploring the multipotentiality of plant extracts for the green synthesis of iron nanoparticles: A study of adsorption capacity and dye degradation efficiency

The goal of the project was to create environmentally friendly and economically viable materials for thoroughly purifying contaminated water. An affordable, phytogenic, and multifunctional plant-based nanomaterial was prepared in this context. The work demonstrates an effective green synthesis method for producing iron nanoparticles (FeNPs) using six different plant extracts as a reducing agent. The characterization of green synthesized catalysts was concluded via Spectroscopy (tauc plot), XRD, FE-SEM, and FT-IR. The produced nanomaterial, which had an X-ray diffractogram (XRD) peak at 43.33⁰ and a size range of 1.82-63.63 nm, functioned as a highly effective nano-photocatalyst for the degradation of cationic dye. Due to the presence of a lower overall secondary metabolites quota, Ocimum sanctum plant extract reduced iron precursor produced the highest yield of dried NPs, followed by Azadirachta indica, Prosopis cineraria, Syzygium cumini, Citrus limon, and Salvadora oleoides. Further, the synthesized catalyst was tested for its effectiveness against gentian violet dye degradation. Ocimum sanctum plant extract reduced iron precursor produced the highest yield of dried NPs, followed by Azadirachta indica, Prosopis cineraria, Syzygium cumini, Citrus limon, and Salvadora oleoides, in that order. The dye removal efficiency of nanoparticles was 51% (Azadirachta indica), 83% (Ocimum sanctum), 59% (Syzygium cumini), 40% (Salvadora oleoides), 59% (Prosopis cineraria), and 63% (Citrus limon) after 12 h of visible light irradiation. The key factor in the process of deterioration is •O^2-. As a result, the nanoparticles can be used in antibacterial and photocatalytic processes. The reduced band gap was responsible for the increased photocatalytic quantity. The maximum adsorption capacity at the time of equilibrium was obtained in order as Ocimum sanctum > Citrus limon > Prosopis cineraria > Syzygium cumini > Azadirachta indica > Salvadora oleoides. The simplicity of production, low cost, magnetic property, and high adsorption capacity will increase the efficacy of the water treatment method. This article reports on the creation of unique iron nanoparticles and their use in the purification of water.

Mesoporous carbon nitride supported MgO for enhanced CO2 capture

The growing concern about the environmental consequences of anthropogenic CO2 emissions significantly stimulated the research of low-cost, efficient, and recyclable solid adsorbents for CO2 capture. In this work, a series of MgO-supported mesoporous carbon nitride adsorbents with different MgO contents (xMgO/MCN) was prepared using a facile process. The obtained materials were tested for CO2 capture from 10 vol% CO2 mixture gas with N2 using a fixed bed adsorber at atmospheric pressure. At 25 ºC, the bare MCN support and unsupported MgO samples demonstrated CO2 capture capacities of 0.99, and 0.74 mmol g-1, respectively, which were lower than those of the xMgO/MCN composites.The incorporation of MgO into the MCN improved the CO2 uptake, and the 20MgO/MCN exhibited the highest CO2 capture capacity of 1.15 mmol g-1 at 25 °C. The improved performance of the 20MgO/MCN nanohybrid can be possibly assigned to the presence of high content of highly dispersed MgO NPs along with its improved textural properties in terms of high specific surface area (215 m2g-1), large pore volume (0.22 cm3g-1), and abundant mesoporous structure. The efffects of temperature and CO2 flow rate were also investigated on the CO2 capture performance of 20MgO/MCN. Temperature was found to have a negative influence on the CO2 capture capacity of the 20MgO/MCN, which decreased from 1.15 to 0.65 mmol g-1with temperature rise from 25 C to 150º C, due to the endothermicity of the process. Similarly, the capture capacity decreased from 1.15 to 0.54 mmol g-1 with the increase of the flow rate from 50 to 200 ml minute-1 respectively. Importantly, 20MgO/MCN showed excellent reusability with consistent CO2 capture capacity over five sequential sorption-desorption cycles, suggesting its suitability for the practical capture of CO2.

Upregulation of RIPK1 implicates in HEK 293T cell death upon transient transfection of A53T-α-synuclein

BACKGROUND

Alpha-synuclein (α-SN) is the central protein in synucleinopathies including Parkinson's disease. Nevertheless, the molecular mechanisms through which α-SN leads to neuronal death remain unclear.

METHODS

To elucidate the relationship between α-SN and apoptosis, some indicators of the intrinsic and extrinsic apoptotic cell death were assessed in normal and a stable HEK293T cell line expressing firefly luciferase after transfection with the wild-type (WT) and A53T mutant α-SN.

RESULTS

Opposite to WT-α-SN, overexpression of A53T-α-SN resulted in enhanced expression of almost two fold for RIPK1 (93.0 %), FADD (45 %), Caspase-8, and Casp-9 activity (52.0 %) in measured time. Transfection of both WT-α-SN and A53T-α-SN showed an increase in the Casp-3/Procasp-3 ratio (WT: 60.5 %; A53T: 41.0 %), Casp-3 activity (WT: 65.0 %; A53T: 20.5 %), and a decrease in luciferase activity (WT: 50 %; A53T: 34.8 %). Overexpression of A53T-α-SN brought about with more cell death percentage compared to WT-α-SN within 36 h. No significant alteration in cytochrome c and reactive oxygen species release into cytosol were observed for both WT-α-SN and A53T-α-SN.

CONCLUSION

Altogether, these findings highlight the link between disease related mutants of α-SN (like A53T-α-SN) in triggering of RIPK1-dependent extrinsic apoptotic pathway in cell death during neurodegeneration.