Transmission Electron Research Articles

Natural Kapok Fiber-derived Two-Dimensional Carbonized Sheets as Sustainable Electrode Material

Natural biomass-derived carbon nanostructures have attracted research interest because of their unique surface and electrochemical properties. The present study embodied the carbonized micro-nano sheets derived from the low-cost natural source Kapok silk fiber. The material was obtained via a facile thermal pyrolysis process. Diffraction analysis showed a broad graphene structure-like peak, indicating the formation of graphene-like carbon nanosheets. Field emission scanning electron microscope (FESEM) and transmission electron microscopic (TEM) images confirmed the presence of fragmented carbon sheets, some of which were folded to form a tube-like structure. Raman study showed the presence of D and G band with the Id/Ig ratio of 0.96 which indicated the formation of few-layered carbon nanosheets. Furthermore, the electrochemical performance was evaluated for lithium-ion battery as well as supercapacitor. A specific capacity of 465 mAh.g-1 at 0.1 C rate for Li-ion battery and a specific capacitance of 473.61 F.g-1 for supercapacitor have been obtained with the capacitance retention of 95%. This study provides insights into a strategy for the sustainable production and utilization of natural fiber-based carbon in energy storage systems.

The use of 1D carbon nanotube interacting with caffeine molecules for applications in solar cells: structure optimisation, Raman analysis and optoelectronic properties

This study proposes a promising candidate for organic solar cells through the creation of a novel nano-hybrid system composed of caffeine molecules encapsulated within a semiconducting single-walled carbon nanotube known as NT14 (14,0). The stability and optoelectronic properties of this hybrid system, designated as CA@NT14, were thoroughly investigated. We determined the optimal diameter for the NT14 nanotube using molecular mechanics, Density Functional Theory, spectral moment’s method, and bond polarizability model, finding it to be approximately 1.18 nm. The encapsulation’s impact on the Raman-active modes, specifically the radial breathing mode and tangential mode, was analyzed through Raman spectra calculations, revealing structural stability and charge transfer from CA to NT14. Notably, the NT14’s Fermi level position increased upon encapsulation, indicating charge transfer and a type-II band alignment. The study further examined the bandgap characteristics of the hybrid system, finding that the encapsulation of CA within semiconducting NT14 nanotubes minimally impacts the nanotube’s bandgap, thus retaining its excellent visible light absorption properties. Conversely, encapsulating CA within metallic nanotubes significantly reduces their bandgap, limiting their light absorption range. The nonresonant Raman responses of NT14 pre- and post-encapsulation corroborated the charge transfer between CA and NT14. Future research will focus on computing the electronic transport characteristics, transmission spectra, I-V characteristics, and yield of CA@NT14 using DFT and Non-Equilibrium Green’s Function ( formalism. An experimental study will be conducted to validate these theoretical findings. These results indicate the potential of CA@NT14 hybrids as effective active layers in organic solar cells, highlighting their significance in advancing optoelectronic applications.

Exfoliation of self-assembled 2D aluminum synthesized via magnetron sputtering

Two-dimensional materials have been rapidly developed in recent years. As a type of two-dimensional material, 2D metals exhibit many unique physical and chemical properties. Here, we prepared two-dimensional aluminum materials via magnetron sputtering. The layers were exfoliated via sonication and annealing methods (thermal exfoliation methods). After exfoliation, the layers were observed via optical microscopy, scanning electron microscopy and transmission electron microscopy. The atomic force microscopy results show that the thicknesses of the layers range from ∼1 nm to ∼45 nm. The simulation results supported those two-dimensional layers formed in a self-assembly process.

A wearable cotton fiber-based supercapacitor electrode material with outstanding stability and photothermal performance utilizing AgNWs, NiCoAl-LDH, and PPy-NWs.

Designing cotton fiber (CF) based flexible electrode materials with both electrochemical energy storage and structural stability is crucial for the utilization of flexible supercapacitors in wearable devices. Nevertheless, the electrochemical properties of such materials are often constrained by suboptimal ion diffusion, a limited electroactive surface area, and inadequate structural integrity. Herein, Silver nanowires (AgNWs), NiCoAl hydrotalcite (NCA-LDH), and polypyrrole nanowires (PPy-NWs) are employed to construct a CF-based electrode material (PNHAS/CF) with high stability through a layer-by-layer self-assembly method. The PNHAS/CF with a high capacitance of 1207.58 mF cm-2 at 5mAcm-2 due to the faster electronic transmission paths of AgNWs and PPy-NWs, and the high specific capacitance of NCA-LDHs. The NCA-LDH stabilizes the PPy-NWs molecular chain, and the PPy-NWs winding structure can further enhance the PNHAS/CF's structural stability and prevent the AgNWs network from being destroyed, which guarantees the exceptional 87.5% capacitance retention after 2000cycles. The constructed symmetrical supercapacitor shows an energy density of 36.28 μWh cm-2 at 0.31mWcm-2 power density. The PNHAS/CF exhibits superb solar spectral absorptivity (~94.8%) and outstanding solar heating performance. Surprisingly, the fiber-based flexible electrode material and the assembled supercapacitor are expected to find applications in wearable intelligent electronics.

Acetylshikonin reduces the spread of antibiotic resistance via plasmid conjugation.

The plasmid-mediated conjugative transfer of antibiotic resistance genes (ARGs) stands out as the primary driver behind the dissemination of antimicrobial resistance (AMR). Developing effective inhibitors that target conjugative transfer represents an efficient strategy for addressing the issue of AMR. Here, we studied the effect of acetylshikonin (ASK), a botanical derivative, on plasmid conjugation. The conjugative transfer of RP4-7 plasmid inter and intra species was notably reduced by ASK. The conjugation process of IncI2 and IncX4 plasmids harboring the mobile colistin resistance gene (mcr-1), IncX4 and IncX3 plasmids containing the carbapenem resistance gene (blaNDM-5), and IncFI and IncFII plasmids possessing the tetracycline resistance gene [tet(X4)] were also reduced by ASK. Importantly, the conjugative transfer frequency of mcr-1 positive IncI2 plasmid in mouse peritoneal conjugation model and gut conjugation model was reduced by ASK. The mechanism investigation showed that ASK disrupt the functionality of the bacterial cell membrane. Furthermore, the proton motive force (PMF) was dissipated. In addition, ASK blocked the electron transmission in bacteria's electron transport chain (ETC) through disturbing the quinone interaction, resulting in an insufficient energy supply for conjugation. Collectively, ASK is a potential conjugative transfer inhibitor, providing novel strategies to prevent the spread of AMR.

The Differential Influence of Biochar and Graphite Precursors on the Structural, Optical, and Electrochemical Properties of Graphene Oxide

This study investigates the synthesis and characterization of graphene oxide (GO) derived from two distinct precursors: graphite and pyrolyzed acacia wood sawdust via a modified Hummers method. As hypothesized, the commercial graphite-derived GO (GOG) exhibited a more ordered structure characterized by a well-defined diffraction peak with interlayer separation of 0.86 nm and crystalline order of 8.18 nm, consistent with extensive oxidation. Conversely, the biochar-derived GO (GOB) displayed a heterogenous structure with a less defined (001) plane and an emerging (002) plane corresponding to mixed hybridization states (sp2/sp3) and mixed crystallinity at different regions in the materials. Additionally, it retained excess aromatic carbons (C-H bond) on its basal plane increasing its disorderliness and defect density. As a result, despite the G bands showing greater incorporation of functional groups in GOG, GOB recorded a higher ID/IG ratio (0.95 vs. 0.93). By retaining a relatively higher proportion of sp2 domains, GOB demonstrated enhanced light absorption through additional electronic transmission evident by its lower bandgap energy (2.93) compared to GOG (4.20), extending absorption into the visible range. Its improved properties were further characterized by enhanced conductivity, surface area, porosity, and decreased charge transfer and ion diffusion resistance. The study emphasizes that the nature of defects and their distribution, influenced by the precursor material can influence GO properties than those predicted by oxidation levels alone. It opens a new pathway to exploring bio-precursors and their potential in tailoring the properties of GO for specific applications.

Liquid-phase shear exfoliation of graphite and its application as corrosion protection coating on aluminum substrate

Although aluminum (Al) or its alloys are moderately protected by a native oxide layer, the presence of chloride ions in aqueous media in direct contact causes pitting attacks and accelerates corrosion. Using graphene as a coating protector can obstruct corrosion due to its numerous chemical and physical properties. This study investigates corrosion protection of Al using graphene nanosheets (GNSs) produced by liquid phase shear exfoliation method (LPE). To do so, few layer-thick graphene nanosheet colloidal solutions were produced by a scalable eco-friendlier lower cost approach. The GNSs were thoroughly characterized using complementary characterization techniques to determine its quality. Spectroscopic and microscopic analyses indicate the synthesis of few-layers graphene (≤ 5 layers) with a high quality. Once approved, the colloidal solution of GNSs was spread over Al substrate by spray coating method, widely used in industrial manufacturing. Raman and near infrared spectroscopies, X-ray diffraction, microscopy techniques including scanning electron, transmission electron and atomic force microscopies were used to investigate morphological and structural behavior of coated GNSs films either on glass or Al substrates. Density functional theory (DFT) calculations revealed the interaction between the two materials is of the physisorption type, with almost no charge transfer and almost no effect of the number of graphene layers. Electrochemical measurements enabled to investigate the corrosion resistance of GNSs films and its stability over time in a 0.5 M sodium chloride (NaCl) solution, similar to marine surroundings. It was found that introducing a GNSs film can indeed reduce the corrosion rate and preserve Al substrate for an extended period.

Fabrication of Chitosan-Cu2O Nanocomposite through Ethanol Assisted Reduction

The semiconducting characteristics of copper oxides have intrigued researchers like photocatalysis and sensors. Coating these nanoparticles with biocompatible polymers like chitosan enhances their properties, such as biocompatibility and non-toxicity, while reducing production costs. This work details the successful in situ production of a biocompatibile nanocomposite, with Cu2O nanoparticles dispersed in a chitosan matrix using ethanol as a reducing agent. Advanced techniques including ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) imaging combined with selected area electron diffraction (SAED) analysis, have been employed to characterize the nanocomposite material with additional relevant properties analyzed.

Design and implementation of an electronic voting system for optimal electoral process

Electronic voting is a tool for increasing the credibility and efficiency of elections in several democracies around the world. In Nigeria, many elections have conducted sub-optimally due to the manual methods employed in voting and transmission of election results. In such cases, electoral officials have been accused of colluding with politicians to alter election results while the results are being transmitted from polling units to results collation centres. To address this problem, this paper proposes and presents a framework for electronic voting and transmission of election results. The proposed system is designed and implemented using a C++-based Visual Studio Integrated Development Environment (IDE) and a MATLAB/Simulink application. This setup allowed for the simulation of the voting process, encryption of voting data, transmission of voting results and decryption of election results. The simulation-based results obtained for the proposed system was compared with that of the existing system. The results indicate that for sample sizes ranging from 2,000 to 7,000 voters, the proposed system accurately accredited an average of 85% of voters, compared to 73% for the existing system. Specifically, for 2,500, 4,000, 5,500, and 7,000 accredited voters, the existing system had 684, 1,095, 1,505, and 1,916 failed voters respectively. In comparison, there was a significant reduction in the number of failed voters for the proposed system and this stood at 364, 582, 801, and 1,019 respectively. Additionally, the quality of verified feedback for 3,000, 4,500, 6,000, and 7,000 accredited voters showed that the proposed system had quality scores of 0.362, 0.138, 0.019, and 0.000, compared to 0.549, 0.197, 0.024, and 0.001 for the existing system. In conclusion, the proposed system has proven to be highly effective, credible, secure, and transparent in safeguarding the integrity of the electoral process and it is therefore recommended for hardware implementation in subsequent general elections.

In-Situ EBSD investigation of how annealed twins produce excellent strength-ductility synergy in Al0.25FeCoNiV duplex high-entropy alloy

The development of high-entropy alloys (HEAs) has been historically constrained by trade-off between strength and ductility. In this study, the Al0.25FeCoNiV duplex HEA showed a yield strength of 625 ± 35.2 MPa and a fracture elongation of 48 ± 1.5 % after rolling and annealing. These values are 43 % and 60 % higher, respectively, than the as-cast specimens, demonstrating an excellent synergy between strength and ductility. Through in-situ electron backscatter diffraction (EBSD) tensile experiments and transmission electron microscopy characterization of the as-cast and annealed specimens, respectively, it is found that the superior mechanical properties of the annealed specimens are primarily attributable to the multilevel strengthening and strain-hardening coupling mechanism established by the synergistic action of phase boundaries (PBs), twin boundaries (TBs), and high-angle grain boundaries. This mechanism effectively suppresses strain localization and prevents premature fracture caused by local stress concentration at PBs. The strengthening mechanism of TBs on the mechanical properties of HEAs was investigated by examining the interaction mechanisms between annealed TBs and dislocations, as well as the coordinated plastic deformation mechanism of twins. This study provides novel insights into the development of innovative HEAs with enhanced properties and advances the understanding of the role of TBs in the strengthening mechanisms of materials.

Rotaxane Based Molecular Junctions Have Emerged as Promising Components For Electronic and Optoelectronic Applications

Background: Rotaxane molecule consists of three main parts: wheel, axle, and stoppers. This study was conducted to increase the number of wheels to get the electronic, electrical and thermal properties of Nano molecular junctions based on rotaxane. Materials and Methods: Calculations were performed to evaluate the transport properties and the geometrically optimization of these molecular junctions using a combination of DFT, SIESTA code, Gollum code and a non-equilibrium Green’s function formalism. Each molecule was attached to opposing 35-atom (111) directed pyramidal gold electrodes. DFT and GGA were used to compute the ground state energy of various molecular junctions. Results: The results of the T(E) showed high values, and this is evidence of that constructive interference that is controlled and reinforced by changing the number of wheels in the rotaxane molecules, which affected the HOMO-LUMO gap and thus contributed to raising or lowering the T(E) values. The relationship between G/Go and thermopower showed that the highest G/Go yields to low thermopower. The decay constant is a fundamental property that influences the transmission of electrons, conductance properties, and threshold voltage in the rotaxane molecules. Conclusion: Molecular junctions based on Rotaxane showed high values of the T(E), which increase the electrical conductivity, making them promising for electronic applications. The smaller value of threshold voltage is a useful property for different applications. The results of power factor bring to us an important conclusion, which is that the impact of G/G0 is more dominant than that of thermopower in the case of rotaxane molecular junctions.

Solvent-induced modulation of sensitivity and selectivity in the self-assembly of tetracationic cyclophanes with cholesterol sulphate, sodium dodecyl sulfate, and sodium dodecyl benzene sulfonate: Observations of significant shifts

Cyclophane CP-1 demonstrates markedly distinct sensitivities toward Cholesterol sulfate (CH-S), Sodium Dodecyl Sulfate (SDS), and Sodium Dodecyl Benzene Sulfonate (SDBS) when the solvent is shifted minimally from a 95 % to a 98 % HEPES-DMSO mixture. In a 98:2 HEPES-DMSO mixture, CP-1 engages in highly selective self-assembly with CH-S, which is characterized by aggregation-induced emission enhancement (AIEE) in contrast to other steroidal sulfates such as pregnenolone sulfate (PRG-S), dehydroisoandrosterone sulfate (DIAND-S), taurocholic acid (TACH-S), and the surfactants SDS and SDBS. This assembly results in an approximate 40-fold increase in fluorescence intensity with three equivalents of CH-S and allows for the detection of concentrations as low as 200 nM under physiological conditions. Dynamic light scattering (DLS) studies illustrate the aggregation of CP-1 and CH-S, with the zeta potential of each shifting from negative values to nearly zero in a 1:2 CP-1:CH-S mixture, indicating self-assembly. This aggregation behavior is reversible, as demonstrated by a corresponding decrease and then increase in fluorescence intensity with temperature variations from 25 °C to 70 °C and back to 25 °C. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) analyses show that CP-1 forms aggregates ranging from 100 to 180 nm, which increase to 150–250 nm upon interaction with CH-S. In a 95:5 HEPES-DMSO mixture, CP-1 exhibits a stronger AIEE response with SDS and SDBS compared to CH-S. Cyclophane CP-2, when dissolved in binary DMSO-water mixtures with water content exceeding 80 %, shows similar AIEE phenomena and undergoes selective fluorescence quenching with SDS and only a 50 % increase in fluorescence intensity with CH-S, irrespective of the HEPES concentration (95 % or 98 %).

5-Fluorouracil adsorption on graphene oxide-amine modified graphene oxide/hydroxyapatite composite for drug delivery applications: Optimization and release kinetics studies

The present study focused on investigation of graphene oxide/hydroxyapatite (GO/HAp) and amine modified graphene oxide/hydroxyapatite (GO-NH2/HAp) composites as potential drug carrier agents for 5-Fluorouracil (5-FU). Incorporation of 5-Fluorouracil drug was performed via adsorption through π-π interactions and electrostatic attractions. Modification of graphene oxide was performed for the production of amine modified graphene oxide/hydroxyapatite composite with the intention of enhancing adsorption performance. The X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA) and zeta potential/particle size analysis were performed for particle characterization while Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) analysis were used to analyze detailed morphological properties. Experimental design studies were followed out in order to determine the effect of adsorption parameters including graphene oxide amount, pH and initial drug concentration on 5-Fluorouracil adsorption behavior. Adsorption isotherms of both composites with unmodified and modified GO were best fitted to Freundlich model with R2 values of 0.9616 and 0.9682 respectively. The maximum adsorption capacities (qm) were calculated as 47.3 mg/g and 18.4 for graphene oxide/hydroxyapatite and amine modified graphene oxide/hydroxyapatite composites respectively at pH 2.0. The highest adsorption percentage was obtained for amine modified graphene oxide/hydroxyapatite composite as 40.87 % at pH 2.0 condition. In vitro release kinetic studies revealed that compliance with Higuchi and Korsmeyer-Peppas kinetic models were observed for graphene oxide/hydroxyapatite, whereas zero order and Korsmeyer-Peppas kinetic models pointed out as the well-fitted model for amine modified graphene oxide/hydroxyapatite composite. The release period of 5-FU drug from all composites were continued up to 8–10 h in physiological conditions (pH 7.4, 37 °C) indicating an achieved controlled release. Based on the overall findings, graphene oxide/hydroxyapatite and amine modified graphene oxide/hydroxyapatite composites could be suggested as a potential drug delivery agent for 5-FU in clinical applications.

Small extracellular vesicles derived from synovial fibroblasts contain distinct miRNA profiles and contribute to chondrocyte damage in osteoarthritis

BackgroundSmall extracellular vesicles (sEV) derived from synovial fibroblasts (SF) represent a novel molecular mechanism regulating cartilage erosion in osteoarthritis (OA). However, a comprehensive evaluation using disease relevant cells has not been undertaken. The aim of this study was to isolate and characterise sEV from OA SF and to look at their ability to regulate OA chondrocyte effector responses relevant to disease. Profiling of micro (mi) RNA signatures in sEV and parental OA SF cells was performed.MethodsSF and chondrocytes were isolated from OA synovial membrane and cartilage respectively (n = 9). sEV were isolated from OA SF (± IL-1β) conditioned media by ultracentrifugation and characterised using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Particle size was confirmed by nanoparticle tracking analysis (NTA). sEV regulation of OA chondrocyte and cartilage effector response was evaluated using qPCR, ELISA and sulphated glycosaminoglycan assay (sGAG). RNA-sequencing was used to establish miRNA signatures in isolated sEV from OA SF.ResultsOA SF derived sEV were readily taken up by OA chondrocytes, with increased expression of the catabolic gene MMP 13 (p < 0.01) and decreased expression of the anabolic genes aggrecan and COL2A1 (p < 0.01) observed. Treatment with sEV derived from IL-1β stimulated OA SF significantly decreased expression of aggrecan and COL2A1 (p < 0.001) and increased SOX 9 gene expression (p < 0.05). OA chondrocytes cultured with sEV from either non-stimulated or IL-1β treated OA SF, resulted in a significant increase in the secretion of IL-6, IL-8 and MMP-3 (p < 0.01). Cartilage explants cultured with sEV from SF (± IL-1β) had a significant increase in the release of sGAG (p < 0.01). miRNA signatures differed between parental SF cells and isolated sEV. The recently identified osteoclastogenic regulator miR182, along with miR4472-2, miR1302-3, miR6720, miR6087 and miR4532 were enriched in sEV compared to parental cells, p < 0.01. Signatures were similar in sEVs derived from non-stimulated or IL-1β stimulated SF.ConclusionsOA SF sEV regulate chondrocyte inflammatory and remodelling responses. OA SF sEV have unique signatures compared to parental cells which do not alter with IL-1β stimulation. This study provides insight into a novel regulatory mechanism within the OA joint which could inform future targeted therapy.

Lunar in-situ ironmaking through laser-assisted flash vacuum pyrolysis of iron oxide

The in-situ metallurgy of lunar regolith minerals for extracting metals and oxygen is a promising approach for the future construction of lunar bases. In this study, a novel laser-assisted flash vacuum pyrolysis (LFVP) method was proposed and developed for the production of metallic iron and oxygen from lunar regolith using iron oxide as raw material. First, the theoretical feasibility of vacuum pyrolysis of FeO was conducted through thermodynamic calculations. Subsequently, an experiment on laser heating of iron oxides was performed, with a reduction rate of FeO of approximately 15.5 % (±0.6 %). Scanning electron microscopy and transmission electron microscopy images revealed that the micronano-level metallic iron exhibited spherical particles, strip-like and irregularly shaped aggregates. The spatial distribution unevenness of the formed metallic Fe, differences in the condensation conditions of gaseous products, and the surface tension effects of liquid metallic iron were mainly attributed to the disparities in the morphology of metallic iron. Meanwhile, the process mechanism of vacuum pyrolysis of FeO was also analyzed. Therefore, LFVP of FeO for producing metallic iron represents a novel ironmaking technology, offering a promising solution for extracting metals and oxygen in situ from lunar minerals for future lunar base construction.

Fabrication of Three-Dimensional Dendritic Ag Nanostructures: A SERS Substrate for Non-Invasive Detection.

This paper discusses the fabrication of three-dimensional dendritic Ag nanostructures, showcasing pronounced Localized Surface Plasmon Resonance (LSPR) effects. These nanostructures, employed in surface-enhanced Raman scattering (SERS), function as sensors for lactic acid in artificial sweat. The dendritic structures of the silver nanoparticles (AgNPs) create an effective SERS substrate, with additional hotspots at branch junctures enhancing LSPR. We achieve differential LSPR effects by varying the distribution and spacing of branches and the overall morphology. Adjustments to electrodeposition parameters, such as current and plating solution protective agents on an anodized aluminum oxide (AAO) base, allow for precise control over LSPR intensities. By pre-depositing AgNPs, the electron transmission paths during electrodeposition are modified, which leads to optimized dendritic morphology and enhanced LSPR effects. Parameter optimization produces elongated rods with main and secondary branches, covered with uniformly sized, densely packed, non-overlapping spherical AgNPs. This configuration enhances the LSPR effect by generating additional hotspots beyond the branch tips. Fine-tuning the electrodeposition parameters improved the AgNPs' morphology, achieving uniform particle distribution and optimal spacing. Compared to non-SERS substrates, our structure amplified the Raman signal for lactic acid detection by five orders of magnitude. This method can effectively tailor SERS substrates for specific analytes and laser-based detection.

Non-thermal atmospheric pressure plasma induces selective cancer cell apoptosis by modulating redox homeostasis

BackgroundAnticancer treatments aim to selectively target cancer cells without harming normal cells. While non-thermal atmospheric pressure plasma (NTAPP) has shown anticancer potential across various studies, the mechanisms behind its selective action on cancer cells remain inadequately understood. This study explores the mechanism of NTAPP-induced selective cell death and assesses its application in cancer therapy.MethodsWe treated HT1080 fibrosarcoma cells with NTAPP and assessed the intracellular levels of mitochondria-derived reactive oxygen species (ROS), mitochondrial function, and cell death mechanisms. We employed N-acetylcysteine to investigate ROS’s role in NTAPP-induced cell death. Additionally, single-cell RNA sequencing was used to compare gene expression in NTAPP-treated HT1080 cells and human normal fibroblasts (NF). Western blotting and immunofluorescence staining examined the expression and nuclear translocation of nuclear factor erythroid 2-related factor 2 (NRF2), a key antioxidant gene transcription factor. We also evaluated autophagy activity through fluorescence staining and transmission electron microscopy.ResultsNTAPP treatment increased ROS levels and induced mitochondrial dysfunction, leading to apoptosis in HT1080 cells. The involvement of ROS in selective cancer cell death was confirmed by N-acetylcysteine treatment. Distinct gene expression patterns were observed between NTAPP-treated NF and HT1080 cells, with NF showing upregulated antioxidant gene expression. Notably, NRF2 expression and nuclear translocation increased in NF but not in HT1080 cells. Furthermore, autophagy activity was significantly higher in normal cells compared to cancer cells.ConclusionsOur study demonstrates that NTAPP induces selective cell death in fibrosarcoma cells through the downregulation of the NRF2-induced ROS scavenger system and inhibition of autophagy. These findings suggest NTAPP’s potential as a cancer therapy that minimizes damage to normal cells while effectively targeting cancer cells.

Antibacterial Efficacy of AgNPs synthesized from Aloe vera extract and Staphylococcus aureus Culture Supernatant

Biological synthesis of silver nanoparticles (AgNPs) is an emerging method that avoids the need for costly equipment and hazardous chemicals. Therefore, in this study, Aloe vera (AV) extract and culture supernatant of Staphylococcus aureus (CS-S. aureus) were used to reduce and stabilise silver nanoparticles. The NPs were characterized using UV–vis spectrophotometry at 445 nm for AV-AgNP and 444.5 nm for CS-S.aureus AgNP, and the presence of silver was confirmed by energy dispersive X-ray (EDX). Furthermore, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that the AV-CS of S. aureus-AgNPs had irregular and spherical shapes, with average sizes of 18.5 nm for AvAgNPs and 7.03 nm for CS-S. aureus-AgNPs. Additionally, the minimum inhibitory concentration (MIC) of both AgNPs showed a similar reaction. K. pneumoniae, P. aeruginosa, and S. epidermidis were more sensitive to the AgNPs compared to methicillin-resistant Staphylococcus aureus (MRSA). In conclusion, our study used a green method to synthesise silver nanoparticles using AV extract and CS of S. aureus. The NPs showed a remarkable antibacterial effect, especially CS-S. aureus-AgNP, which could have application as a treatment against both Gram-positive and Gram-negative bacteria.

Construction of electrochemical immunosensor from MXene/multi-walled carbon nanotubes/gold nanoparticles for specific detection of carcinoembryonic antigen.

With the advancement of nanotechnology, various types of nanomaterials have been integrated into electrochemical immunoelectrodes to enhance their performance. Among these, MXene stands out as a promising candidate due to its high electron transfer capacity and abundant surface chemical groups. However, the improvement in electrode performance is often hindered by the self-restacking and agglomeration of MXene. To address this issue, multi-walled carbon nanotubes (MWCNTs) were selected to form composites with MXene. Subsequently, a label-free immunosensor, BSA/Ab/AuNPs/MXene-MWCNTs-Nafion/ITO, was fabricated for specific detection of carcinoembryonic antigen (CEA), a widely used tumor marker. The results demonstrated that the incorporation of MWCNTs can effectively prevent the self-stacking of MXene. Moreover, the composites enhanced the loading of gold nanoparticles (AuNPs) to connect the antibodies, thereby improving electronic transmission signals and sensitivity. The sensor exhibited excellent analytical performance towards CEA with a wide linear range (0.050 to 200ngmL-1) and a low limit of detection of 0.015ngmL-1 (S/N = 3). The possibility of it being applied in clinical trials was verified by using ELISA and differential pulse voltammetry (DPV) assays to detect CEA in serum samples. The recoveries ranged from 95.34 to 102.09% with relative standard deviations (RSDs) below 5.00%. Furthermore, the sensor displayed satisfactory selectivity, repeatability, and stability. We hope the findings highlight promising prospects for advanced immunosensor development and alternative strategies in cancer diagnosis.

Development and Characterization of Gingerol-Assisted Silver Nanoparticle and Chitosan Alginate Membrane for Antibacterial and Wound Healing Activity.

This study synthesized and characterized gingerol-loaded silver nanoparticles (Ag-NPs), which were incorporated into chitosan-alginate (Cs/Alg) films for advanced wound care applications. Gingerol was isolated with a 9.81% yield, forming pale-yellow needle-shaped crystals with a melting point of 32ºC. The purity and structure of gingerol were confirmed through thin-layer chromatography (TLC), UV-visible, fourier-transform infrared spectroscopy (FTIR), and high-performance liquid chromatography (HPLC) analyses. The synthesized Ag-NPs, particularly from the GN3 batch, exhibited a small particle size (36.52 ± 3.52 nm), high stability (zeta potential of -23.20 mV), and notable encapsulation efficiency (76.35%) and yield (74.11%). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses revealed their spherical and smooth morphology. Stability tests over three months showed no substantial changes in particle size, ZP, or %EE. The Cs/Alg films demonstrated appropriate thickness, weight, water uptake, and pH changes, with GN-CM4 showing the best performance. In-vitro drug release studies indicated increased release rates, especially for GN-CM4, which also exhibited the highest antibacterial activity. In-vivo studies on excision and burn wound models showed that GN-CM4 promoted complete wound closure by day 21, enhanced hydroxyproline levels, reduced myeloperoxidase content, and facilitated superior tissue regeneration. These findings underscore the potential of gingerol-loaded Ag-NPs in enhancing wound healing through their anti-inflammatory and antibacterial properties.