Surface Of Nanoparticles Research Articles

Wood sponge with photothermal, magnetically driven, and superhydrophobic characteristics for high-viscosity oil–water separation

In this work, naturally degradable porous balsa wood was used as a raw material to prepare a highly elastic wood sponge (WS) substrate using a two-step chemical method and a freeze-drying method. The surface hydrophobic modification of Fe3O4 nanoparticles using the fluorine-free material octadecyltrimethoxysilane (C18TMS) solved the problem of agglomeration caused by the high nanoparticle surface energy. Polydopamine (PDA), hydrophobically modified Fe3O4 (C18TMS/Fe3O4), and low-surface-energy polydimethylsiloxane (PDMS) were sprayed onto WS substrates using a simple spraying method. An environmentally friendly adsorption sponge with photothermal, magnetically driven, and superhydrophobic properties was prepared for the first time using this method. The prepared sponge had a water droplet contact angle of 156.8° and exhibited excellent oil–water separation performances. Due to the addition of PDA and Fe3O4, the modified sponge exhibited excellent photothermal performance, rapidly heating to 63.4°C under a sunlight intensity of 1 kW m−2. The superhydrophobic WS prepared in this experiment provides a more environmentally friendly and low-cost way for high viscosity oil–water separation and targeted removal of oil pollution.

Folic acid-mediated enhancement of the diagnostic potential of luminescent europium-doped hydroxyapatite nanocrystals for cancer biomaging

Early and accurate cancer diagnosis is crucial for improving patient survival rates. Luminescent nanoparticles have emerged as a promising tool in fluorescence bioimaging for cancer diagnosis. To enhance diagnostic accuracy, ligands promoting endocytosis into cancer cells are commonly incorporated onto nanoparticle surfaces. Folic acid (FA) is one such ligand, known to specifically bind to folate receptors (FR) overexpressed in various cancer cells such as cervical and ovarian carcinoma. Therefore, surface modification of luminescent nanoparticles with FA can enhance both luminescence efficiency and diagnostic accuracy. In this study, luminescent europium-doped hydroxyapatite (EuHAp) nanocrystals were prepared via hydrothermal method and subsequently modified with (3-Aminopropyl)triethoxysilane (APTES) followed by FA to target FR-positive human cervical adenocarcinoma cell line (HeLa) cells. The sequential grafting of APTES and then FA formed a robust covalent linkage between the nanocrystals and FA. Rod-shaped FA-modified EuHAp nanocrystals, approximately 100 nm in size, exhibited emission peaks at 589, 615, and 650 nm upon excitation at 397 nm. Despite a reduction in photoluminescence intensity following FA modification, fluorescence microscopy revealed a remarkable 120-fold increase in intensity compared to unmodified EuHAp, attributed to the enhanced uptake of FA-modified EuHAp. Additionally, confocal microscope observations confirmed the specificity and the internalization of FA-modified EuHAp nanocrystals in HeLa cells. In conclusion, the modification of EuHAp nanocrystals with FA presents a promising strategy to enhance the diagnostic potential of cancer bioimaging probes.

A novel Fe3O4@Pt synthetized via a self-assembly strategy as efficient Fenton-like@mimetic enzyme catalyst for degradation of tetracyclines in food processing wastewater

The self-assembly approach has successfully been used to generate Fe3O4@Pt, a material that can mimic peroxidase. The material was created by modifying the surface of Fe3O4 nanoparticles (Fe3O4 NPs) with -NH2 functional groups using 3-Aminopropyltriethoxysilane (APTES), and then using the coordination between platinum ions and -NH2 on the surface of magnetic particles to reduce platinum ions to the surface of magnetic particles under ultrasonic conditions to produce Fe3O4@Pt composite nanoparticles. The Fe3O4@Pt core-shell composite material not only has the inert metal Pt to protect Fe3O4 to improve the stability of Fe3O4 in the biological matrix, but also has the high catalytic activity of Fe3O4 and Pt. The catalysts were characterized, and the findings revealed that they were non-homogeneous Fenton catalysts with high dispersion, uniform particle size, and a large specific surface area. Since a large number of free radicals generated during the catalysis of Fe3O4@Pt mimic enzyme can trigger the Fenton reaction, tetracycline (TC) and oxytetracycline (OTC) were chosen as target substances, and a system for the combined degradation of tetracyclines pollutants by mimic enzyme and Fenton reaction was established, and the catalytic mechanism of this system has been investigated. The findings indicate that by using a concentration of 0.25 mol/L of H2O2, a catalyst amount of 1.5 g/L, a reaction time of 50 min, and a reaction temperature of 50°C, the degradation rate of TC and OTC can exceed 97 %, following first-order degradation kinetics. Under ideal conditions, over 95 % of each tetracyclines was degraded in the simulated food processing wastewater, effectively achieving tetracyclines degradation in the actual wastewater. In addition, the reusability of the recovered Fe3O4@Pt mimetic enzyme was investigated. The findings indicated that the Fe3O4@Pt mimetic enzyme has exceptional activity, stability, and reproducibility. The combination of the Fenton reaction with the Fe3O4@Pt mimetic enzyme can expedite the degradation of tetracyclines, offering a novel approach for eliminating recalcitrant contaminants in wastewater.

Green and sustainable synthesis of the ZnONPs using leaf extract of Guazuma ulmifolia for antioxidant and antimicrobial activities

AbstractThe main objectives of the current study were synthesis and characterization of zinc oxide nanoparticles (ZnONPs) using the aqueous leaf extract of Guazuma ulmifolia (G. ulmifolia) plant and assessing its antimicrobial and antioxidant potential. The nanoparticles were characterized using Ultraviolet Visible (UV–Vis), Fourier Transform Infrared (FTIR) Spectroscopy, X-ray diffraction (XRD), Energy-dispersive X-ray (EDS) and Scanning electron microscopy (SEM). ZnONPs exhibited a maximum peak at 342 nm in the UV–Vis spectrum, indicating their absorption properties. FTIR analysis confirmed the presence of functional groups, such as OH and COOH which likely contributed to the stability of the nanoparticles. The XRD analysis confirmed the spherical structure of the nanoparticles as indicated by distinct diffraction peaks corresponding to the lattice planes of the ZnO standard. The EDS analysis confirmed the presence of Zn, C and O in the ZnONPs. SEM analysis provided insights into the nanoparticles size, shape and surface morphology, showing an average size between 19 and 41 nm. Furthermore, the synthesized ZnONPs demonstrated excellent antioxidant and antibacterial activities against various bacteria and Candida species. This study highlights the promising potential of ZnONPs in diverse fields, including biomedicine, due to their low toxicity, economic viability and beneficial properties. It is crucial to conduct further in vivo investigations in order to determine the safety, effectiveness and compatibility of G. ulmifolia ZnONPs.

Surface modified PLGA nanoparticles of gabapentin: Biodistribution and pharmacodynamic investigation via intranasal route

Epilepsy is a chronic condition and is caused by abnormal electrical conduction by nerve cells. It can affect people from different age groups. The prime objective of epilepsy therapeutics is the targeted and sustained release of drugs at the site of action i.e. in the brain. In the present study, PLGA nanoparticles of gabapentin, coated with Polysorbate 80 were prepared with the aim of delivering the drug to the brain through the nasal route. The said nanoparticles were formulated by the method of double emulsion and solvent evaporation. Thereafter, the prepared nanoparticles were characterized for particle size, Zeta potential, and Surface morphology of the nanoparticles was evaluated by SEM &TEM In vitro release in PBS (pH 7.4) and SNF (pH 5.5). In addition, FTIR and DSC techniques were used to confirm the P80 coating around the nanoparticle's surface. In vitro, cell assays like Cytotoxicity studies, and quantitative and qualitative cell uptake studies were studied on Neuro-2a cells. The nasal mucosa of the goat was used to perform histopathological studies to evaluate the toxicity of nanoparticles. A biodistribution study was performed on Swiss albino mice and the results showed that the concentration of the drug reaching the brain in the case of P80 modified nanoparticles was maximum as compared to Plain PLGA nanoparticle, and aqueous solution of the drug. Pharmacodynamic studies were performed to assess the delay in different phases of convulsion and the results showed that the modified nanoparticles of gabapentin were able to significantly delay the episodes of convulsion. Overall, results demonstrate that modified nanoparticles are potential drug carriers in the brain for the management of epilepsy.

Preparation and Characterization of C@Fe3O4 Supported Pd Magnetic Nanoparticles for Degradation of Dye Wastewater

The core-shell structure Fe3O4@C magnetic nanoparticles were synthesized with superparamagnetic Fe3O4 nanosphere as a magnetic core, and soluble starch resin as a carbon source via a solvothermal method. Silica-iron oxide and Fe3O4@C carriers with a core-shell structure were prepared by carbonization of organic material on the surface of Fe3O4 nanoparticles, Fe3O4@C supported Pd were processed into magnetic nano-catalysts with core-shell structure, and their catalytic properties were investigated. The resulting environmentally friendly magnetic material can be used to degrade dye wastewater. The structure of magnetic nanoparticles was characterized using TEM, XRD and VSM. The effects of preparation conditions in the structure of the Fe3O4@C magnetic nanoparticles were taken out. The results indicate that from XRD, the magnetic nano particles Fe3O4@C synthesized of carbon sources have amorphous carbon diffraction peak except for all the characteristic peaks of Fe3O4. The saturation magnetization Fe3O4, Fe3O4@SiO2 and Fe3O4@C – 59.14 emu/g, 49.12 emu/g and 27.95 emu/g, respectively.

Gadolinium Schiff-base complex on nanocomposite of graphene oxide magnetic nanoparticles as a robust, reusable and chemoselective nanocatalyst in the C–C coupling reactions

Graphene is an important phase of carbon, which is easily available and oxidable to graphene oxide with a variety of applications. Therefore in this work, graphene oxide (GO) was synthesized, and further it was magnetized by nickel magnetic nanoparticles. The surface of graphene oxide magnetic nanoparticles (Ni-GO MNPs) was modified with (3-aminopropyl)triethoxysilane (APTES). On the other hand, (3,4-bis(−(2-hydroxybenzylidene)amino)phenyl)(phenyl)methanone Schiff-base ligand (bis(HBAPM)) was synthesized using condensation of salicylaldehyde and 3,4-diaminobenzophenone. In the next step, bis(HBAPM) was immobilized on the surface of modified Ni-GO MNPs toward synthesis of immobilized Schiff-base on Ni-GO MNPs (bis(HBAPM)@Ni-GO MNPs) as a heterogeneous Schiff-base ligand. In the final step, the gadolinium catalyst was stabilized on its surface (Gd-bis(HBAPM)@Ni-GO MNPs) as a robust, reusable, efficient, chemoselective, and novel nanocatalyst. Gd-bis(HBAPM)@Ni-GO MNPs were characterized by nitrogen adsorption/desorption, FT-IR, SEM imaging, EDS analysis, WDX analysis, XRD, and VSM analysis. After the characterization of Gd-bis(HBAPM)@Ni-GO MNPs, its catalytic performance was employed as a highly practical, retrievable, stable, and hybrid organic–inorganic catalyst in the carbon–carbon coupling of the Suzuki reaction. Due to the recoverability and heterogeneous nature of Gd-bis(HBAPM)@Ni-GO MNPs, it can recycled again for 5 runs.

Fluoride-Ion-Responsive Sol-Gel Transition in an L-Cysteine/AgNO3 System: Self-Assembly Peculiarities and Anticancer Activity.

Supramolecular hydrogels based on low-molecular-weight compounds are a unique class of so-called "soft" materials, formed by weak non-covalent interactions between precursors at their millimolar concentrations. Due to the variety of structures that can be formed using different low-molecular-weight gelators, they are widely used in various fields of technology and medicine. In this study, we report for the first time an unusual self-assembly process of mixing a hydrosol obtained from L-cysteine and silver nitrate (cysteine-silver sol-CSS) with sodium halides. Modern instrumental techniques such as viscosimetry, UV spectroscopy, dynamic light scattering, zeta potential measurements, SEM and EDS identified that adding fluoride anions to CSS is able to form stable hydrogels of a thixotropic nature, while Cl-, Br- and I- lead to precipitation. The self-assembly process proceeds using a narrow concentration range of F-. An increase in the fluoride anion content in the system leads to a change in the gel network morphology from elongated structures to spherical ones. This fact is reflected in a decrease in the gel viscosity and a number of gel-sol-gel transition cycles. The mechanism of F-'s interaction with hydrosol includes the condensation of anions on the positive surface of the CSS nanoparticles, their binding via electrostatic forces and the formation of a resulting gel carcass. In vitro analysis showed that the hydrogels suppressed human squamous carcinoma cells at a micromolar sample concentration. The obtained soft gels could have potential applications against cutaneous malignancy and as carriers for fluoride anion and other bioactive substance delivery.

Fabrication of black phosphorus/CdS heterostructure with enhancement photocatalytic degradation activity for tetrabromobisphenol A and toxicity prediction of intermediates

Black phosphorus nanosheets (BPNs)/CdS heterostructure was successfully synthesized via hydrothermal method. The experimental results indicated that BPNs modified the surface of CdS nanoparticles uniformly. Meanwhile, the BPNs/CdS heterostructure exhibited a distinguished high rate of photocatalytic activity for Tetrabromobisphenol A (TBBPA) degradation under visible light irradiation (λ > 420 nm), the kinetic constant of TBBPA degradation reached 0.0261 min−1 was approximately 5.68 and 9.67 times higher than that of CdS and P25, respectively. Moreover, superoxide radical (•O2−) is the main active component in the degradation process of TBBPA (the relative contribution is 91.57%). The photocatalytic mechanism and intermediates of the TBBPA was clarified, and a suitable model and pathway for the degradation of TBBPA were proposed. The results indicated that the toxicities of some intermediates were higher than the parent pollutant. This research provided an efficient approach by a novel photocatalyst for the removal of TBBPA from wastewater, and the appraisal methods for the latent risks from the intermediates were reported in this paper.

Targeted degradation of oncogenic BCR-ABL by silencing the gene of NEDD8 E3 ligase RAPSYN

Tyrosine kinase inhibitors have been the standard treatment for patients with Philadelphia chromosome-positive (Ph+) leukemia. However, a series of issues, including drug resistance, relapse and intolerance, are still an unmet medical need. Here, we report the targeted siRNA-based lipid nanoparticles in Ph+ leukemic cell lines for gene therapy of Ph+ leukemia, which specifically targets a recently identified NEDD8 E3 ligase RAPSYN in Ph+ leukemic cells to disrupt the neddylation of oncogenic BCR-ABL. To achieve the specificity for Ph+ leukemia therapy, a single-chain fragment variable region (scFv) of anti-CD79B monoclonal antibody was covalently conjugated on the surface of OA2-siRAPSYN lipid nanoparticles to generate the targeted lipid nanoparticles (scFv-OA2-siRAPSYN). Through effectively silencing RAPSYN gene in leukemic cell lines by the nanoparticles, BCR-ABL was remarkably degraded accompanied by the inhibition of proliferation and the promotion of apoptosis. The specific targeting, therapeutic effects and systemic safety were further evaluated and demonstrated in cell line-derived mouse models. The present study has not only addressed the clinical need of Ph+ leukemia, but also enabled gene therapy against a less druggable target.Graphical

Impact of protein corona and PEGylation on the accumulation and efficacy of lysosome-disrupting lipid nanoparticles in KRAS-mutated cancer

Nanomedicines offer promising approaches for targeted drug delivery to tumor cells but their clinical translation is hindered by limited delivery efficacy in heterogenous clinical tumors. Protein corona adsorbed to the surface of nanoparticles (NPs) would cause opsonization and accelerate blood clearance, posing a significant barrier to effective drug delivery. Polyethylene glycol (PEG) modification is widely employed to prolong the NPs’ circulation time and improve the delivery efficacy. Nevertheless, the clinical efficacy of PEG-based nanomedicines is still debatable. Here, we prepared non-PEGylated lysosomal-disrupting dimeric chloroquine (CQ) lipid nanoparticles (DCLNPs) and PEGylated DCLNPs (PEG-DCLNPs) and systematically studied the impact of PEGylation on DCLNPs’ delivery efficacy in KRAS-mutant (MT) and -wildtype (WT) cancers. We found that the protein corona facilitates KRAS-MT cancer-specific targeted delivery of DCLNPs by exploiting extracellular protein engulfment preference. In contrast, PEGylation hindered delivery and efficacy of DCLNPs. Proteomics analysis highlighted apolipoproteins, particular apolipoprotein E, as key factors promoting the uptake of DCLNPs. Additionally, DCLNPs sensitized immunosuppressive KRAS-MT cancers to anti-PD1 immunotherapy. These results underscore the importance of comprehending the context-dependent role of the protein corona in regulating nanoparticle biodistribution, suggesting that PEGylation may not be suitable across all cancer types.

GOLD PLASMONIC ARRAY STRUCTURES FOR SENSING APPLICATIONS

This article is devoted to the theoretical study of the plasmonic properties of periodically arranged arrays of gold nanoparticles. The Comsol Multiphysics software, which is based on the finite element method, was used to build 3D numerical models for the simulation and conduct research. In this work the electric field distribution and optical characteristics of the spherical gold nanoparticles array were studied. Individual localized surface plasmon resonance modes are influenced when metallic nanoparticles are in the close proximity and as a result the electric near- fields can couple, resulting in a new hybrid mode. We mainly focused here on the investigation of two crucial questions, particularly, influences of the gap between the nanoparticles and the refractive index of the surrounding medium on the resulting optical response of the gold nanoparticles arrays. The array of periodically arragement gold nanoparticles is characterized by an enhanced local electric field between the nanoparticles, which is inversely proportional to the gap between the particles. The field strength and optical properties (reflection, transmission, and absorption) can be conveniently manipulated by changing the gap between particles. In additional, their potential applications as sensetive plasmonic sensors element have been considered. The studied structure has a significant potential for practical applications due to its wide range of the operating wavelengths and ease of the high-throughput fabrication. In the course of the study, it was established that the change in the distance between the surface of nanoparticles by 1 nm leads to a significant shift in the spectral transmission and reflection curves on the spectral range. In addition, these studies showed that an increase in the distance between the surfaces of nanoparticles leads to the decrease in the near-field interaction between gold nanoparticles in the array. Therefore, the obtained results can be successfully used in the manufacture of highly sensitive plasmon sensors with the possibility of controlling the sensitivity and the working spectral range.

Ultrasensitive and Rapid Circulating Tumor DNA Liquid Biopsy Using Surface-Confined Gene Amplification on Dispersible Magnetic Nano-Electrodes.

Circulating tumor DNA (ctDNA) detection has been acknowledged as a promising liquid biopsy approach for cancer diagnosis, with various ctDNA assays used for early detection and treatment monitoring. Dispersible magnetic nanoparticle-based electrochemical detection methods have been proposed as promising candidates for ctDNA detection based on the detection performance and features of the platform material. This study proposes a nanoparticle surface-localized genetic amplification approach by integrating Fe3O4-Au core-shell nanoparticles into polymerase chain reactions (PCR). These highly dispersible and magnetically responsive superparamagnetic nanoparticles act as nano-electrodes that amplify and accumulate target ctDNA in situ on the nanoparticle surface upon PCR amplification. These nanoparticles are subsequently captured and subjected to repetitive electrochemical measurements to induce reconfiguration-mediated signal amplification for ultrasensitive (∼3 aM) and rapid (∼7 min) metastatic breast cancer ctDNA detection in vitro. The detection platform can also detect metastatic biomarkers from in vivo samples, highlighting the potential for clinical applications and further expansion to rapid and ultrasensitive multiplex detection of various cancers.

Highly conductive titanium nitride core sterically reinforced nickel-vanadium layered double hydroxides for supercapacitors

Nickel vanadium layered double hydroxide (NiV-LDH) is a highly promising electrode material for supercapacitors, but its poor electrochemical durability and conductivity limit its capacitance performance as a high-performance supercapacitor electrode. In contrast, titanium nitride (TiN) stands out for its outstanding electrochemical durability and superior conductivity. In this work, a composite material (TiN@NiV-LDH) with outstanding electrochemical performance was prepared by a simple hydrothermal method, where nickel vanadium layered double hydroxide nanosheets were vertically grown in a staggered manner on the surface of amorphous titanium nitride nanoparticles. The results demonstrate that at a current density of 2 A g−1, the capacitance of TiN@NiV-LDH reaches 712.4 F g−1. In addition, the assembled TiN@NiV-LDH//AC asymmetric supercapacitor exhibits a high energy density of 136.5 Wh kg−1 at a high power density of 1549.9 W kg−1, and after 10,000 cycles at a high current density of 20 A g−1, it retains 80.2 % excellent cyclic stability. This work, based on nickel vanadium layered double hydroxide and utilizing titanium nitride modification, aims to enhance the long-term stability of nickel vanadium layered double hydroxide while preserving its advantageous properties, providing a promising strategy for designing efficient supercapacitor electrodes.

Zinc Oxide:Gold Nanoparticles (ZnO:Au NPs) Exhibited Antifungal Efficacy Against Aspergillus niger and Aspergillus candidus

Fungal pathogens are a major health issue that threatens the era of antifungal drugs commonly used in the treatment of infections. An effective approach of biosynthetic nanoparticles can be used as antifungal agents owing to their intrinsic features such as their simplicity, non-toxic, and physicochemical properties. Therefore, this study was aimed to molecularly ascertain Aspergillus species known to cause aspergillosis and investigate the potency of zinc oxide:gold nanoparticles (ZnO:Au NPs) against the fungal pathogens. Two Aspergillus strains retrieved with potato dextrose agar (PDA) culture media from commercial food products in South Africa were molecularly identified using calmodulin (CaM) gene region. DNA sequence phylogeny of the gene showed that the strains were A. niger and A. candidus. ZnO:Au (1%) NPs were synthesised and characterised using X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Two distinct peak plasmon bands for ZnO and ZnO:Au NPs were 390 nm and 565 nm, respectively. FE-SEM images demonstrated the presence of Au on the surface of ZnO nanoparticles in the ZnO:Au nanocomposites. The ZnO:Au NPs antifungal activity of 10 µg/mL and 50 µg/mL concentrations were evaluated against the two Aspergillus spp. ZnO:Au NPs at 50 µg/mL exhibited a maximum antifungal activity against A. candidus and A. niger, with zones of inhibition (ZoI) of 31.2 ± 0.15 mm and 25.0 ± 0.06, respectively. When the ZoI was observed by SEM, major morphological damages on the conidia were observed for both strains, indicating that the antifungal activity may have been enhanced by the ZnO:Au NPs. Therefore, due to these outstanding properties, ZnO:Au NPs can be utilised as potential antifungal agents to inhibit the proliferation of fungal pathogens.

A simple, controllable, and scalable synthetic strategy for highly uniform N-doped carbon coating on nanoparticles

The carbon coating enables nanoparticles to withstand harsh environments, but achieving uniformity and scalability for their industrial use remains a challenge. In this work, we present a simple, controllable, and scalable strategy for one-pot coating with an N-doped carbon layer on the surface of various nanoparticles, including semiconductors, oxides, transition metals, and noble metals. Uniform coverage of the N-doped carbon layer was achieved through an autogenic pressure reaction of gaseous species derived from starting precursors in a closed reactor. The thickness of the coating layer could be precisely controlled by adjusting the amount of precursor, even down to the 1 nm level, because the precursor is completely consumed in the reactor without any loss. The crystallinity of the N-doped carbon layer could be modified by altering the coating temperature. Moreover, the results demonstrate that this coating process can be applied to different types of nanoparticles. Tests confirmed that nanoparticles retain their inherent nature while exhibiting more stable and enhanced properties after the N-doped carbon coating. We believe this approach offers a straightforward synthetic route for the design and application of nanoparticle coatings.

Biocompatible polyethersulfone membrane modified by hydrophilic polymer decorated magnetic nanoparticles gilded by facile external magnetic field

AbstractPolymer‐based membranes such as polyethersulfone are widely used for hemodialysis and bio‐related applications; however, this type of membrane still fails to satisfy optimum performance in terms of clearance, safety, and bio‐adaptability. Herein, a polymer brush of polyvinylpyrrolidone is decorated on the surface of magnetic nanoparticles by using reversible addition‐fragmentation chain transfer polymerization (RAFT), and under the guidance of an external magnetic field, the prepared magnetic nanoparticles with the polymer brush system are blended with a polyethersulfone membrane during a liquid‐liquid phase inversion process. The prepared membranes with different loads of the pure magnetic nanoparticle and polyvinylpyrrolidone@magnetic nanoparticle polymer brushes are prepared, compared with the pristine membrane, the modified membrane shows a high flux value at 349 L m−2 h−1 and 99.9% bovine serum albumin protein rejection. This membrane also demonstrated improved hydrophilicity and pore structure compared with the pristine membrane. Concerning the blood biocompatibility analysis, the modified membranes acquire prolonged time for clotting factors such as prothrombin time, activated partial thromboplastin time, and thrombin time while exhibiting less fibrinogen concertation at 0.4 g L−1. Furthermore, for the first time, an innovative method for fouling detection based on magnetic field attenuation due to protein accumulation on the membrane surface is reported; the method in this work could be a positive booster for the safe use of polymeric membranes in hemodialysis and bio‐based applications.

Mechanistic Insights Behind the Self-Assembly of Human Insulin under the Influence of Surface-Engineered Gold Nanoparticles.

Elucidating the underlying principles of amyloid protein self-assembly at nanobio interfaces is extremely challenging due to the diversity in physicochemical properties of nanomaterials and their physical interactions with biological systems. It is, therefore, important to develop nanoscale materials with dynamic features and heterogeneities. In this work, through engineering of hierarchical polyethylene glycol (PEG) structures on gold nanoparticle (GNP) surfaces, tailored nanomaterials with different surface properties and conformations (GNPs-PEG) are created for modulating the self-assembly of a widely studied protein, insulin, under amyloidogenic conditions. Important biophysical studies including thioflavin T (ThT) binding, circular dichroism (CD), surface plasmon resonance (SPR), and atomic force microscopy (AFM) showed that higher-molecular weight GNPs-PEG triggered the formation of amyloid fibrils by promoting adsorption of proteins at nanoparticle surfaces and favoring primary nucleation rate. Moreover, the modulation of fibrillation kinetics reduces the overall toxicity of insulin oligomers and fibrils. In addition, the interaction between the PEG polymer and amyloidogenic insulin examined using MD simulations revealed major changes in the secondary structural elements of the B chain of insulin. The experimental findings provide molecular-level descriptions of how the PEGylated nanoparticle surface modulates protein adsorption and drives the self-assembly of insulin. This facile approach provides a new avenue for systematically altering the binding affinities on nanoscale surfaces by tailoring their topologies for examining adsorption-induced fibrillogenesis phenomena of amyloid proteins. Together, this study suggests the role of nanobio interfaces during surface-induced heterogeneous nucleation as a primary target for designing therapeutic interventions for amyloid-related neurodegenerative disorders.

Creating Atomically Iridium-Doped PdOx Nanoparticles for Efficient and Durable Methane Abatement.

The urgent environmental concern of methane abatement, attributed to its high global warming potential, necessitates the development of methane oxidation catalysts (MOC) with enhanced low-temperature activity and durability. Herein, an iridium-doped PdOx nanoparticle supported on silicalite-1 zeolite (PdIr/S-1) catalyst was synthesized and applied for methane catalytic combustion. Comprehensive characterizations confirmed the atomically dispersed nature of iridium on the surface of PdOx nanoparticles, creating an Ir4f-O-Pdcus microstructure. The atomically doped Ir transferred more electrons to adjacent oxygen atoms, modifying the electronic structure of PdOx and thus enhancing the redox ability of the PdIr/S-1 catalysts. This electronic modulation facilitated methane adsorption on the Pd site of Ir4f-O-Pdcus, reducing the energy barrier for C-H bond cleavage and thereby increasing the reaction rate for methane oxidation. Consequently, the optimized PdIr0.1/S-1 showed outstanding low-temperature activity for methane combustion (T50 = 276 °C) after aging and maintained long-term stability over 100 h under simulated exhaust conditions. Remarkably, the novel PdIr0.1/S-1 catalyst demonstrated significantly enhanced activity even after undergoing harsh hydrothermal aging at 750 °C for 16 h, significantly outperforming the conventional Pd/Al2O3 catalyst. This work provides valuable insights for designing efficient and durable MOC catalysts, addressing the critical issue of methane abatement.

The Influence of Blood and Serum Microenvironment on Spin-Labeled Magnetic Nanoparticles

The investigation and clarification of the properties of surface-functionalized superparamagnetic nanoparticles in a biological environment are key challenges prior to their medical applications. In the present work, electron paramagnetic resonance spectroscopy (EPR) combined with the spin labeling technique was utilized to better understand the behavior of nitroxides attached to magnetite nanoparticles dispersed in body fluid. EPR spectra of spin-labeled, silane-coated Fe3O4 nanoparticles in human serum and whole blood were recorded and analyzed for both room- and low-temperature values. In all cases, the obtained EPR signal consisted of a broad line from magnetite cores and a characteristic signal from the attached 4-Amino-2,2,6,6-tetramethylpiperidine-1-oxyl (4-amino-TEMPO). Even for liquid samples, the anisotropic components of magnetic tensors did not fully average out, which was reflected in the differences in the intensity of three narrow hyperfine lines from nitroxide. At 230 K the irregular slow-motion signal from the attached radical was also simulated using the EasySpin toolbox, which allowed to determine the parameters related to magnetic tensors and the dynamics of the spin label. The study showed that the anisotropy of the motion of the spin label 4-amino-TEMPO reflects its interactions with the surrounding medium and the manner of the attachment of the nitroxide to the surface of nanoparticles.