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Accurate diagnostic and serology assays are required for the continued management of the COVID-19 pandemic yet spike protein mutations and intellectual property concerns with antigens and antibodies used in various test kits render comparability assessments difficult. As the use of common, well-characterized reagents can help address this lack of standardization, the National Research Council Canada has produced two protein reference materials (RMs) for use in SARS-CoV-2 serology assays: biotinylated human angiotensin-converting enzyme 2 RM, ACE2-1, and SARS-CoV-2 Omicron BA.4/5 spike protein RM, OMIC-1. Reference values were assigned through a combination of amino acid analysis via isotope dilution liquid chromatography tandem mass spectrometry following acid hydrolysis, and ultraviolet–visible (UV–Vis) spectrophotometry at 280 nm. Vial-to-vial homogeneity was established using UV–Vis measurements, and protein oligomeric status, monitored by size exclusion liquid chromatography (LC-SEC), was used to evaluate transportation, storage, and freeze–thaw stabilities. The molar protein concentration in ACE2-1 was 25.3 ± 1.7 µmol L−1 (k = 2, 95% CI) and consisted almost exclusively (98%) of monomeric ACE2, while OMIC-1 contained 5.4 ± 0.5 µmol L−1 (k = 2) spike protein in a mostly (82%) trimeric form. Glycoprotein molar mass determination by LC-SEC with multi-angle light scattering detection facilitated calculation of corresponding mass concentrations. To confirm protein functionality, the binding of OMIC-1 to immobilized ACE2-1 was investigated with surface plasmon resonance and the resulting dissociation constant, KD ~ 4.4 nM, was consistent with literature values. [ABSTRACT FROM AUTHOR]

Waste tires, used in combination with polymers, have been extensively employed in the construction of asphalt pavements. The performance of these hybrid asphalts varies depending on the manufacturing process, the characteristics of the neat binder, and other factors. The present study aims to investigate the effect of crumb rubber, polymer, and neat asphalt on physicochemical and rheological properties of terminal blend rubberized asphalt (TBRA). Thermal gravimetric (TG) testing was performed to analyze the component distribution of different crumb rubber modifiers (CRMs). Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), and solubility and storage stability tests were used to characterize the physicochemical properties of TBRA binders. The rotational viscosity (RV) test, high-temperature performance grade (PG), and rheological master curve were used to compare the rheological properties of various TBRA binders, respectively. Results indicated that crumb rubber and neat binder characteristics, as well as the addition of polymer, impact TBRA performance. However, the influence of neat binder and polymer is more significant than that of crumb rubber. The primary differences in the physicochemical properties of TBRA prepared with different crumb rubber types are related to solubility and degradation degree. The interaction between Zhonghai neat asphalt and crumb rubber is weaker than that of ESSO and Jinshan asphalt, as evidenced by a comparison of molecular weight distribution. Moreover, 3.0% styrene-butadiene-styrene (SBS) polymer can significantly improves the elastic property of TBRA produced with ESSO neat asphalt, which is evidenced by similar phase angle plateau region with 4.5% SBS modified asphalt. [ABSTRACT FROM AUTHOR]

In this study, the influence of flame-retardant materials on the rheological properties of warm-mix asphalt was investigated. The rheological properties of base asphalt and styrene–butadiene–styrene-modified (SBS) asphalt modified with 2% Sasobit and flame-retardant materials, such as alumina trihydrate and organic montmorillonite (OMMT) in a proportion of 3:1 (AM), were systematically explored. The investigation was carried out under three dosages of AM; i.e., 4%, 8%, and 12%. Experiments including dynamic shear rheological tests, multiple stress creep recovery tests, bending beam rheometer tests, Fourier transform infrared (FTIR) spectroscopy tests, gel permeation chromatography (GPC) tests, and fluorescence microscopy (FM) tests were conducted to evaluate the rheological properties and micromechanism of warm-mix flame-retardant asphalt under different AM dosages. The results showed that the rheological properties of warm-mix flame-retardant SBS asphalt (SOA) at high and low temperatures were better than those of warm-mix flame-retardant asphalt (POA) at the same AM dosage. The increase in AM dosage improved the high-temperature rheological properties and decreased the low-temperature rheological properties. Based on the combined analysis of FTIR spectroscopy, GPC results, and FM results, the reason for this phenomenon was speculated to be the occurrence of wax-crystal structure and filler–asphalt interaction between asphalt and AM. Furthermore, organic cations in OMMT adsorbed the lightweight components present in asphalt, which reduced their proportion and improved the high-temperature and rheological properties. Moreover, the increase in AM led to the increase in physical volume filling, which increased the mechanical properties and brittleness of asphalt. The stress concentration led to the worsening of the stress-diffusion capacity of POA and SOA and eventually led to the decrease in the low-temperature rheological properties of POA and SOA. [ABSTRACT FROM AUTHOR]

Polycarboxylate superplasticizers (PCEs) have been extensively used in the areas of construction and building; however, the application limitation of PCEs has emerged owing to their sensitivity to clay. In this work, three anticlay PCEs were synthesized by introducing acrylamide (AM), methacryloxyethyltrimethyl ammonium chloride (DMC), or 3-[2-(methacryloyloxy) ethyl] dimethylammonio-propane-1-sulfonate (DMAPS) into the polycarboxylate copolymer of ethylene glycol monovinyl polyethylene glycol ether (EPEG) and acrylic acid (AA), denoted as A-PCE, D-PCE, and S-PCE, respectively. The structures of these superplasticizers were characterized by gel permeation chromatography (GPC) and Fourier-transform infrared spectroscopy (FTIR). Compared with the common polycarboxylate superplasticizers (O-PCEs), the resultant anticlay PCEs showed better dispersion as far as the fluidity of cement paste and mortar were concerned. With the content of 0.5% per weight sodium bentonite in place of cement, these anticlay PCEs exhibited better clay resistance than O-PCE. In addition, the compressive strengths of mortar and concrete by the addition of A-PCE, D-PCE, or S-PCE were slightly higher than those of O-PCE. Total organic carbon (TOC) revealed that the sensitivity of A-PCE, D-PCE, and S-PCE to clay was lower than that of O-PCE. X-ray diffraction (XRD) proved that the layer spacing of clay increased after treatment with superplasticizer. In combination of adsorption determination with XRD analysis, a possible mechanism was proposed. Unlike the PEG side chains inserting into the clay layers for O-PCE, the cations in functional groups entered the clay layers through cation exchange for anticlay PCEs preferentially. [ABSTRACT FROM AUTHOR]

Capparis masaikai Lévl is a Chinese native plant that ripe seeds are often used as a traditional Chinese medicine for their heat antidotes properties. The locals like to chew the seeds for their distinctive flavor "sweet water taste". In this study, enzymatic hydrolysis, gel filtration chromatography, and reversed-phase high-performance liquid chromatography were used to extract, isolate and purify flavor peptides from the seed kernels of Capparis masaikai Lévl. Nano-LC−MS/MS was used to identify 219 peptides in total. Five new bitter peptides (HIGP, FHP, CFR, LYR and SFR) were screened by molecular docking. The results of molecular docking indicated that hydrogen bonds and hydrophobic bonds played essential roles in the binding of the five bitter peptides to T1R2-T1R3, T2R1 and T2R34. Phe75 and Glu74 on T2R1 and Arg373 on T1R2-T1R3 might be the critical amino acids in the binding site. The taste properties of the synthesized peptides were confirmed by sensory evaluation, and it was found that five peptides exhibited a specific sweetness inhibition. Not only do these results shed light on the interaction between flavor peptides and taste receptors, but they also help explain the "sweet water taste" of the seed kernels of Capparis masaikai Lévl. The results of this study help to explore the potential of flavor peptides in an enzymatic hydrolysate of Capparis masaikai Lévl seed kernels and broaden the diversity of flavor sources for the "sweet water taste". [ABSTRACT FROM AUTHOR]

This study explores the purification and impact of metal ions on Aspergillus niger tannase, a metalloenzyme. Gel permeation chromatography achieved a 22.03-fold purification, yielding a specific activity of 106 U/mg. The enzyme, confirmed as a homodimer (100 kDa native, 50 kDa SDS PAGE), exhibited enhanced activity in the presence of calcium ions, reaching 163.46 U/mg, a 1.42-fold increase. UV absorption with 6 µM Ca ions indicated structural stability. Kinetic studies revealed a sigmoidal Michaelis–Menten graph with calcium ions, suggesting allosteric effects. The Lineweaver–Burk plot showed increased Km (14.04 to 36.39 mM) with mercuric ions, indicating competitive inhibition, while Vmax remained stable. Reactivation studies with DTT and different metal ions showed maximum reactivation with Hg (88.8%) and Ag (81.4%), implicating binding with cysteine residue in inactivation. EDTA-induced reactivation displayed maximum reactivation with Cu ions (67.6%) and minimum with Hg (22.5%), indicating Cu ions form complexes with amino acid groups. In contrast, Hg forms a coordination sphere with the thiol group of a cysteine residue. This comprehensive examination provides insights for optimizing tannase-based processes in various industries and expanding its biotechnological applications. [ABSTRACT FROM AUTHOR]

This work focused on the characterization of lignin residues from bioethanol production of olive stones (OS) and the use of these residues to chemically thicken epoxidized linseed oil (ELO). OS were processed by an acid/steam explosion pretreatment, followed by pre-saccharification, using different enzyme dosages, and simultaneous saccharification and fermentation. The chemical composition of the OS lignin residues was analysed, revealing a high lignin content (66.6–69.5%), and lower quantities of glucan (17.4–19.3%) and xylan (2.8–2.9%). Whereas, the structural properties of OS lignin residues were characterized by Fourier-transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR), thermogravimetric analysis and size exclusion chromatography (SEC). OS lignin residues displayed the main inter-unit linkages (β–β′ resinol (51.0–59.0%), followed by β-O-4′ alkyl aryl ethers (27.0–35.2%) and β-5′ phenylcoumaran (11.4–13.2%) substructures), high molecular weights (22,000–25900 Da), low S/G ratios (1.2–1.5) and phenolic groups content (48–55 mg GAE/g lignin). Moreover, OS lignin residues were dispersed in ELO to obtain thickened formulations, which were characterized by FTIR and NMR. Oil thickening was achieved by promoting the chemical crosslinking between lignocellulose hydroxyl groups and ELO epoxy groups, enabling the compatibilization of both components. Up to tenfold viscosity increment of the resulting thickened formulations in relation to ELO's viscosity was observed. Besides, thickened formulations exhibited viscoelastic properties, evincing oil structuration to some extent. [ABSTRACT FROM AUTHOR]

Hexagonal boron nitride (hBN), also known as white graphene, has recently gained larger attention due to its unique physical and chemical properties. Owing to its excellent thermal conductivity and stability, hBN has been reported as an effective filler in many polymers. This study explores the potential of hBN as a catalyst support and filler for olefin polymerization. We report the atomic layer deposition (ALD) of γ‐Al2O3 on hydroxyl‐functionalized hBN. The alumina precursor, methylaluminoxane, showed high selectivity, depositing Al species only on the B‐OH sites, while B−O‐O−B sites remained unreacted. The hBN/γ‐Al2O3 hybrid was characterized by Fourier transform infrared (FTIR) spectroscopy, X‐Ray diffraction and transmission electron microscopy (TEM). The deposition of the aluminum over the hBN sheets was confirmed. The hBN/γ‐Al2O3 was used as a support for metallocene catalysts. The supported catalyst complex was highly active and produced ethylene‐propylene polymers with molecular weights up to 10 times higher, as demonstrated by gel permeation chromatography (GPC) [ABSTRACT FROM AUTHOR]

Background: Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne zoonotic disease that presents with severe hemorrhagic manifestations and is associated with significant fatality rates. The causative agent, Crimean-Congo Hemorrhagic Fever Virus (CCHFV), is a high-priority pathogen identified by the World Health Organization with no approved vaccine or specific treatment available. In addition, there is a critical need for enhanced diagnostic tools to improve public health awareness, prevention measures, and disease control strategies. Methods: We designed plasmids to enable the purification of soluble CCHFV glycoprotein Gc expressed in mammalian 293 F cells, followed by purification using affinity and size exclusion chromatography. The purified antigen was analyzed by SDS-PAGE and Western blotting to confirm its reactivity to antibodies from CCHF survivors. Additionally, an in-house indirect ELISA was developed using the purified Gc as a coating antigen. Results: The optimized expression system successfully produced soluble and pure Gc antigen after affinity chromatography. The protein showed specific reactivity with CCHFV-positive serum antibodies in Western blot analysis. The indirect ELISA assay demonstrated high efficacy in distinguishing between CCHFV-positive and -negative serum samples, indicating its potential as a valuable diagnostic tool. Size exclusion chromatography further confirmed the presence of aggregates in our protein preparation. Conclusions: The purified Gc antigen shows promise for developing direct diagnostic assays for CCHFV. The antigen's suitability for subunit vaccine development and its application as bait for monoclonal antibody isolation from survivors could be investigated further. This work lays the foundation for future research into the development of rapid diagnostic tests for field deployment. [ABSTRACT FROM AUTHOR]

To improve the prognosis of bladder and prostate cancer, highly specific and sensitive biomarkers are needed for early detection, prognosis prediction, and therapeutic stratification. Extracellular vesicles (EV) from plasma could fill this gap due to their potential to serve as cancer biomarkers. However, the enrichment of EV is a major challenge, because the highly abundant plasma proteins are interfering with analytical downstream applications like mass spectrometry (MS). Therefore, the purity requirements of the EV samples must be carefully considered when selecting or developing a suitable EV enrichment method. The aim of this study was to compare a self-designed EV enrichment method based on density cushion centrifugation (DCC) combined with size exclusion chromatography (SEC) and concentration (method 1) with the exoRNeasy midi kit from Qiagen (method 2) and with unprocessed plasma. Furthermore, the single steps of method 1 were evaluated for their effectiveness to enrich EV from plasma. The results showed that the EV samples enriched with method 1 contained the highest levels of EV and exosome markers with simultaneously low levels of highly abundant plasma proteins. In summary, the combination of DCC, SEC and concentration proved to be a promising approach to discover EV-based biomarkers from plasma of cancer patients. [ABSTRACT FROM AUTHOR]

Background: In recent years, lytic polysaccharide monooxygenases (LPMOs) that oxidatively cleave cellulose have gained increasing attention in cellulose fiber modification. LPMOs are relatively small copper-dependent redox enzymes that occur as single domain proteins but may also contain an appended carbohydrate-binding module (CBM). Previous studies have indicated that the CBM "immobilizes" the LPMO on the substrate and thus leads to more localized oxidation of the fiber surface. Still, our understanding of how LPMOs and their CBMs modify cellulose fibers remains limited. Results: Here, we studied the impact of the CBM on the fiber-modifying properties of NcAA9C, a two-domain family AA9 LPMO from Neurospora crassa, using both biochemical methods as well as newly developed multistep fiber dissolution methods that allow mapping LPMO action across the fiber, from the fiber surface to the fiber core. The presence of the CBM in NcAA9C improved binding towards amorphous (PASC), natural (Cell I), and alkali-treated (Cell II) cellulose, and the CBM was essential for significant binding of the non-reduced LPMO to Cell I and Cell II. Substrate binding of the catalytic domain was promoted by reduction, allowing the truncated CBM-free NcAA9C to degrade Cell I and Cell II, albeit less efficiently and with more autocatalytic enzyme degradation compared to the full-length enzyme. The sequential dissolution analyses showed that cuts by the CBM-free enzyme are more evenly spread through the fiber compared to the CBM-containing full-length enzyme and showed that the truncated enzyme can penetrate deeper into the fiber, thus giving relatively more oxidation and cleavage in the fiber core. Conclusions: These results demonstrate the capability of LPMOs to modify cellulose fibers from surface to core and reveal how variation in enzyme modularity can be used to generate varying cellulose-based materials. While the implications of these findings for LPMO-based cellulose fiber engineering remain to be explored, it is clear that the presence of a CBM is an important determinant of the three-dimensional distribution of oxidation sites in the fiber. [ABSTRACT FROM AUTHOR]

The rheological properties of polymers before and after mixing are of primary concern because of the damage to the original molecular weight of polymers during processing. In order to reveal the correlation between mixing speed, rheological properties of polymer melts, and their molecular weight parameters, different grades of polybutadiene rubber (BR) at different mixing speeds were prepared in this study. Furthermore, the selected samples were subjected to the dynamic melt viscoelasticity test using a rubber process analyzer (RPA). The molecular weight changes of BR after mixing were observed on a rheological basis to analyze the effects of mechanical shear and thermo-oxidative aging on the molecular weight and distribution of the rubber. The measured values were directly compared with those obtained from gel permeation chromatography (GPC). The results showed that lower mixing speeds did not significantly affect the number-mean molecular weight (Mn), while the Z-mean molecular weight (Mz) and the weight-mean molecular weight (Mw) were increased, and the molecular weight distribution (MWD) was expanded. In addition, a transition state between thermo-oxidative aging and mechanical shear was further demonstrated. The behavior of the rubber was further elucidated and validated through large-amplitude oscillatory shear (LAOS) tests and thermal stability tests, demonstrating that the gel is a manifestation of the molecular weight coalescence of rubber and associating it with the mixing process of BR. According to the results of the RPA tests, melt rheology characterization is an environmentally friendly and fast way to provide information about the molecular structure of the BR. [ABSTRACT FROM AUTHOR]

Two key challenges in the multidisciplinary field of sequence‐controlled polymers are their efficient synthesis and the establishment of correlation with polymer properties. In this context, in this paper, gradient architecture in the hydrophobic tail of an amphiphile is implemented and synthesized for a fixed hydrophilic unit (polyethylene glycol, PEG), by means of two monomers (2‐hydroxypropyl methacrylate, HPMA, and diacetone acrylamide, DAAM) of contrasting reactivities. The resulting non‐biochemical gradient sequence‐controlled polymers are generated from a one‐pot, homogeneous mixture through a PET‐RAFT‐PISA (photoinduced electron/energy transfer‐reversible addition‐fragmentation chain transfer‐polymerization‐induced self‐assembly) method. In addition, the initial concentration ratio of the monomers in the gradient is varied as an input for a set of fixed experimental parameters and conditions, and its correlation with kinetics, gradient and self‐assembled morphologies is established, as the output of the process. These results are extensively corroborated via nuclear magnetic resonance (NMR) spectroscopy analysis, together with transmission electron microscopy (TEM) images, dynamic light scattering (DLS), and gel permeation chromatography (GPC) experiments. These results have implications for chemical computation carried out by PISA, programmable self‐assembly, information storage, biomimetics, origins of life and synthetic protocell studies. [ABSTRACT FROM AUTHOR]

Three novel Schiff base polymers were synthesized by using the Schiff base monomer obtained using aldehyde containing boric acid and amines containing hydroxyl groups as the starting materials. The polymers were synthesized at the same temperature and using the same amount of oxidizing agent by the oxidative polycondensation method. The characterization of all polymers and monomers was achieved by using Fourier transform infrared spectroscopy (FT-IR), ultraviolet–visible spectroscopy (UV–vis), nuclear magnetic resonance spectroscopy (1H-NMR), liquid chromatography-mass spectrometry (LC–MS), gel permeation chromatography (GPC) and scanning electron microscopy (SEM). The thermal stability of these compounds was studied by employing thermogravimetric analysis (TGA), and thermodynamics parameters such as activation energy (Ea), enthalpy (∆H), entropy (∆S), and Gibbs free energy(∆G) for the decomposition process were calculated using the Flynn–Wall–Ozawa method. [ABSTRACT FROM AUTHOR]

To achieve efficient degradation of crustacean raw materials and eco-preparation of N-acetyl-oligosaccharides, YS-54 strain screened from offshore soil in Qingdao was used for chitinase preparation in the present study. Chitinase was prepared through 60% ammonium sulfate precipitation and Sephadex G-100 gel filtration chromatography. Enzymatic properties such as optimal temperature, optimal pH, and substrate specificity were characterized. Mass spectrometry was used to determine the polymerization degree of enzymatic products. The 16S rRNA identification result showed that YS-54 strain belonged to the Aeromonas species. Chitinase from Aeromonas sp. YS-54 showed a specific activity of 23.44 U/mg. The molecular weights of chitinase were 63 and 75 kDa as shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Chitinase was stable under the condition of 40 °C and pH5.0. The enzymatic activity was significantly activated by Ba2+, Co2+, Mg2+ and TritonX-100 (P<0.05), while inhibited by Fe3+, Cu2+ and SDS. The specific activity of chitinase toward α-chitin was 7.99 U/mg, 34.09% of that toward colloidal chitin. The polymerization degree of enzymatic hydrolysis products from colloidal chitin and α-chitin were 1~4 and 1~3, respectively. Chitinase from Aeromonas sp. YS-54 was stable in broad range of temperature and pH, meanwhile showed high catalytic efficiency toward α-chitin. The hydrolysis characteristics of chitinase from Aeromonas sp. YS-54 would provide technical support for the comprehensive utilization of crustacean waste. [ABSTRACT FROM AUTHOR]

Introduction: Semen cryopreservation is the most popular practice for semen production for artificial insemination and in vitro fertilization in cattle. The Seminal plasma contains extracellular vesicles (spEVs) which modulate sperm viability and function during oocyte fecundation. The study of spEVs in frozen-thawed semen doses may yield novel indicators for predicting bull fertility, but the presence of the semen extendermay hindermolecular profiling of spEVs. The aim of this study was to provide extensive characterization of EVs isolated from seminal plasma before and after the cryopreservation process and the addition of a commercial animal protein-free semen extender to understand the potential influence of EVs originating from the extender in hindering the use of spEVs derived biomarkers for assessment of bull fertility. Methods: EVs were isolated from the seminal plasma (with or without the extender), from the cryopreserved straw devoid of spermatozoa, and from the extender using two different methods, ultracentrifugation (UC) and size exclusion chromatography (SEC), and characterized for their structure and composition. Results: Physical characterization of EVs showed that size and particle numbers were related to the method of isolation. spEVs were larger but less abundant (UC: 168.9 nm, n = 2.68 × 109; SEC: 197.0 nm, n = 6.42 × 109) compared to extender EVs (UC: 129.0 nm, n = 2.68 × 1011; SEC: 161.8 nm, n = 6.47 × 1011). Western blotting analysis (WB) confirmed the presence of typical EV markers in spEVS: the membrane bound CD9 (25 kDa) and the luminal markers Alix (96 kDa) and TSG101 (48 KDa). Although Transmission Electron Microscopy confirmed the presence of a lipid bilayer structure in all preparations, no specific EV markers were detected in the vesicles isolated from extender when the Single Molecule Array (SiMoa) was used. A total of 724 Bos taurus miRNAs were identified in at least one preparation. The percentage of miRNAs identified in EVs from the extender (0.05%-0.49% of the total reads) was lower than in the preparation containing spEVs (10.56%-63.69% of the total reads). Edge-R identified a total of 111 DE-miRNAs between EVs isolated from the extender by two methods. Among them, 11 DE-miRNAs (bta-miR-11980, bta-miR-11987, bta-miR-12057, bta-miR-1246, bta-miR-125b, bta-miR-181b, bta-miR-2340, bta-miR-2358, bta-miR-2478, bta-miR-2898, and bta-miR-345-3p) were also abundant in EVs isolated from seminal plasma preparations with extender. Conclusion: This study clearly demonstrates that the presence of the extender does not prevent the characterization of spEVs in cryopreserved semen. However, the molecular profiling of spEVs can be influenced by the isolation method used and by the presence of somemiRNAs fromthe extender. Therefore, in such studies, it is advisable to characterize both spEVs and the vesicles isolated from the extender. [ABSTRACT FROM AUTHOR]

A UV‐ and thermo‐responsive polyurethane‐acrylate prepolymer was synthesized from palm olein (POo) via a non‐isocyanate route. The process included epoxidation of POo, carbonation of epoxidized palm olein (EPOo) into polycyclic carbonate in a solvent‐free and mild condition (100°C, 1 atm), followed by reacting with ethylene diamine and acrylic acid. The chemical structure of the non‐isocyanate polyurethane‐acrylate (NIPUA) prepolymer was elucidated by 1H and 13C nuclear magnetic resonance (NMR) and Fourier transform‐infrared spectroscopy (FTIR), while weight average molecular weight of NIPUA was determined by gel permeation chromatography (GPC). The NIPUA (0–20 wt%) was incorporated with thermoplastic elastomer (TPE) as a plasticizer and cured under UV light and thermal stimulations. The cured NIPUA/TPE films were characterized by FTIR, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and tensile strength test. Under UV and thermal stimulations, the NIPUA/TPE demonstrated enhanced tensile properties (elongation at break >1280%, Young's modulus ~25 MPa), thermal properties (lower Tg), lower water contact angle, and shortened curing time as compared with the blank TPE. The 20 wt% NIPUA/TPE films exhibited susceptibility to enzymatic biodegradation and noncytotoxic to HEK 293 cells in vitro, demonstrated it's potential as a UV‐ and thermo‐responsive plasticizer for TPE in manufacturing of medical devices. [ABSTRACT FROM AUTHOR]

A pH responsive non‐isocyanate polyurethane‐acrylate (NIPUA) is synthesized through utilizing palm olein and sunflower oil as feedstock. The unsaturated acyl chains of both vegetable oils are converted into epoxy rings through epoxidation and subjected to carbonation with binary catalytic system under a solventless and mild condition to produce the cyclic carbonates. The cyclic carbonates were reacted with 1,4‐butanediamine and itaconic acid to produce the NIPUA. The intermediates and product were characterized by FTIR spectroscopy, NMR spectroscopy and gel permeation chromatography. The NIPUA was incorporated with poly(vinyl pyrrolidone) (PVP) to form a polymer carrier system loaded with a hydrophobic model drug, lovastatin (LOV). All NIPUA/PVP preformulations demonstrated pH responsiveness, with 1 to 2‐folds enhanced solubility at pH 7.4 compared to pH 2.0. NIPUA/PVP exhibited solubility enhancer effect by significantly enhanced solubility (2–4 times) compared to pure LOV, LOV‐loaded PVP, and Medostatin tablets at both pH levels. LOV‐loaded NIPUA/PVP exhibited lower enthalpy energy in DSC thermogram than LOV‐loaded PVP, indicating disruption of LOV's crystalline structure. In MTT assay, IC50 values were 30.76 μg mL−1 for pure LOV and 273.53 μg mL−1 for NIPUA/PVP, demonstrating the potential of NIPUA as an environmentally friendly, pH responsive drug carrier for controlled release of poorly water‐soluble drugs. [ABSTRACT FROM AUTHOR]

Pineapple (Ananas comosus) fruit is a functional food that has become a part of healthy diets worldwide due to its nutrition and health benefits. Given this concept, the potential anti-hypercholesterolemic activity of pineapple fruit was assessed using in vitro HMG-CoA reductase (HMGCR) inhibition assay. Our findings show that pineapple fruit (PAF) extract showed HMGCR inhibition activity. These findings led to partial purification of PAF extract by gel filtration chromatography (GFC) whereby fraction PAF 06 exhibited 100.00% HMGCR inhibition at 10 mg/mL. Matrix assisted laser desorption ionization (MALDI) mass spectrometry profiling, HRMS, MS/MS, and dereplication identified N1, N10-diferuloylspermidine as potential HMGCR inhibitor in pineapple fruit. The MALDI mass spectrometry imaging (MSI) enabled the in situ spatiotemporal mapping of the HMGCR inhibitor, N1, N10-diferuloylspermidine, in the pineapple fruit tissue, with localization concentrated mainly in the tissue near the peel/shell and a gradual decrease towards the flesh and ovary. The MALDI MSI provided the first evidence of in situ spatial localization of N1, N10-diferuloylspermidine, a potential HMGCR inhibitor in pineapple while maintaining the cellular and structural features of the fruit tissues. [ABSTRACT FROM AUTHOR]

The determination of molar masses and their distributions is crucial in polymer synthesis and design. This work presents the current performance and limitations of diffusion‐ordered spectroscopy (DOSY) on a low‐field (benchtop) NMR spectrometer (at 90 MHz) as an alternative to size exclusion chromatography (SEC) for determining diffusion coefficient distributions (DCDs) and molar mass distributions (MMDs). After optimization for narrowly distributed homopolymers, MMDs obtained with inverse Laplace transformation (ILT) and log‐normal distribution are compared with average molar masses obtained with mono‐ and bi‐exponential fits, as well as MMDs obtained from SEC. This approach enables ILT to determine DCDs and MMDs even for bimodal homopolymers with fully spectrally overlapping signals and block copolymers with various chemical compositions, for which chemical composition profiles are determined. The feasibility of low‐field diffusion NMR with samples dissolved in non‐deuterated solvents is further demonstrated and methods for solvent suppression are discussed. [ABSTRACT FROM AUTHOR]

Polycaprolactone (PCL) is a pivotal biopolymer in biomedicine, especially in tissue engineering for scaffolds and biomaterials. Recognized for its effectiveness as a drug carrier with superior controlled release properties, PCL is commonly processed via electrospinning, typically employing chlorinated or fluorinated solvents known for cellular toxicity. As an environmentally conscious alternative, this study explores glacial acetic acid (AA) as a solvent for electrospinning solutions. Investigating PCL's molecular degradation through acid hydrolysis in acidic solvents (AA/formic acid) (FA), the study assesses the impact of storage time on resulting structures. Solutions containing 30% PCL in AA/FA (9:1) were stored at 35°C for up to 14 days, revealing a 50% molar mass reduction during solubilization through gel permeation chromatography, x‐ray diffraction, and Fourier‐transform infrared analyses. This reduction influenced chain packing, raising crystallinity indices from approximately 37% to 49% with prolonged storage. The reduced molar mass resulted in unstable Taylor cones, generating diverse mat morphologies. Intriguingly, this degradation enhanced water adsorption capacity, indicating exposed hydrogen bonds from acid hydrolysis as an advantageous trait for regenerative medicine. This underscores the hydrolyzed materials' potential for cell anchoring in tissue engineering. [ABSTRACT FROM AUTHOR]

Carbon‐chain dendritic polymers hold unique properties and promising applications. However, synthesizing carbon‐chain dendrimers, beyond conjugated ones, remains a challenge. Here, the use of the iterative single unit monomer insertion technique for synthesizing 2.5 generation partial‐carbon‐chain dendrimers (G2.5) is described, utilizing bismaleimide as the core, a maleimide–trithiocarbonate conjugate as the branching unit, and indene as the spacer unit, following a divergent growth strategy. The optimized conditions for synthesizing the maleimide–trithiocarbonate branching unit are a bismaleimide to trithiocarbonate ratio of 5:1 and a reaction time of 30 min. The structures are verified using 1H nuclear magnetic resonance, gel permeation chromatography, and matrix‐assisted laser desorption/ionization‐time of flight mass spectra. A four‐arm star polymer is then synthesized using the G2.5 as the core. This synthesis of a partial‐carbon‐chain dendrimer establishes a foundational step toward creating all‐carbon‐chain ones and may open new application avenues in material science. [ABSTRACT FROM AUTHOR]

Background: Extracellular vesicles (EVs) represent small lipid bilayer structures pivotal in mediating intercellular communication via biomolecular transfer. Their inherent characteristics, including packaging, non-immunogenicity, and biofluid stability, position EVs as promising drug delivery vectors. However, developing clinical quality EVs requires multifaceted technological advancement. Methods: In this study, a method is introduced for engineering extracellular vesicles (eEVs) from cultured cells and their subsequent isolation using lab-scale tangential flow filtration (TFF). This is the first study to evaluate DNA loading efficacy into EVs isolated by TFF, marking a significant milestone in the field of targeted drug delivery. Initially, cells are transfected with EV-display constructs to facilitate the secretion of eEVs bearing the desired coding molecules. Following brief centrifugation, the cell culture media undergoes filtration using hollow fiber filters. TFF, by applying a constant flow, effectively segregates molecules based on designated molecular weight cut-off (MWCO), enriching particles between 50 and 650 nm. Results: Compared to conventional methods like ultracentrifugation, TFF demonstrates higher efficiency in removing undesired molecules/aggregates while exerting less stress on EVs. Characterization of eEVs through various assays confirms TFF's superiority in isolating pure EV populations. Additionally, the necessity of size-exclusion chromatography (SEC) after tangential flow filtration (TFF) becomes evident for effectively removing unbound protein contaminants. Conclusion: In conclusion, TFF-SEC emerges as a scalable and superior approach for eEV isolation, promising significant advancements in clinical applications. [ABSTRACT FROM AUTHOR]

Skeletal muscle (SM) acts as a secretory organ, capable of releasing myokines and extracellular vesicles (SM‐EVs) that impact myogenesis and homeostasis. While age‐related changes have been previously reported in murine SM‐EVs, no study has comprehensively profiled SM‐EV in human models. To this end, we provide the first comprehensive comparison of SM‐EVs from young and old human primary skeletal muscle cells (HPMCs) to map changes associated with SM ageing. HPMCs, isolated from young (24 ± 1.7 years old) and older (69 ± 2.6 years old) participants, were immunomagnetically sorted based on the presence of the myogenic marker CD56 (N‐CAM) and cultured as pure (100% CD56+) or mixed populations (MP: 90% CD56+). SM‐EVs were isolated using an optimised protocol combining ultrafiltration and size exclusion chromatography (UF + SEC) and their biological content was extensively characterised using Raman spectroscopy (RS) and liquid chromatography mass spectrometry (LC‐MS). Minimal variations in basic EV parameters (particle number, size, protein markers) were observed between young and old populations. However, biochemical fingerprinting by RS highlighted increased protein (amide I), lipid (phospholipids and phosphatidylcholine) and hypoxanthine signatures for older SM‐EVs. Through LC‐MS, we identified 84 shared proteins with functions principally related to cell homeostasis, muscle maintenance and transcriptional regulation. Significantly, SM‐EVs from older participants were comparatively enriched in proteins involved in oxidative stress and DNA/RNA mutagenesis, such as E3 ubiquitin‐protein ligase TTC3 (TTC3), little elongation complex subunit 1 (ICE1) and Acetyl‐CoA carboxylase 1 (ACACA). These data suggest SM‐EVs could provide an alternative pathway for homeostasis and detoxification during SM ageing. [ABSTRACT FROM AUTHOR]

Polyrotaxane (PR) has garnered increasing attention due to its unique structure and exceptional performance. In this study, a polypseudorotaxane (PPR) initiator was prepared through the self-assembly of bromine-capped Pluronic F68 and β-cyclodextrins (β-CD) in water. Polyrotaxane-containing triblock copolymers (PR copolymers) were successfully synthesized by atom transfer radical polymerization (ATRP) of butyl methacrylate (BMA) using the PPR initiator in the presence of Cu(I)Br/PMDETA. The structure of the PR copolymers was thoroughly characterized using infrared spectroscopy (IR), proton nuclear magnetic resonance (1H NMR), and gel permeation chromatography (GPC). The mobility of β-CD in the PR copolymers was demonstrated through dielectric measurements. Mechanical tests, including tensile strength assessments, thermal mechanical analysis, and dynamic mechanical analysis, confirmed the excellent mechanical properties and good processability of the PR copolymer, attributed to the PBMA blocks. Furthermore, the mechanical properties were found to be modulated by the motility of the threaded β-CDs. Consequently, the superior mechanical properties and the high mobility of the threaded β-CDs suggest promising potential for the as-prepared PR polymer in various advanced applications. [ABSTRACT FROM AUTHOR]

For the application of poly(lactic acid) (PLA) and PLA/starch composites in technical components such as toys, it is essential to know their degradation behavior under relevant application conditions in a hydrothermal environment. For this purpose, composites made from PLA and native potato starch were produced using twin-screw extruders and then processed into test specimens, which were then subjected to various one-week ageing processes with varying temperatures (23, 50, 70, 90 °C) and humidity levels (10, 50, 75, 90%). This was followed by mechanical characterization (tensile test) and identification of degradation using Gel Permeation Chromatography (GPC), Thermogravimetric Analysis (TGA), Fourier Transform Infrared Spectroscopy (FTIR), and Nuclear Magnetic Resonance spectroscopy (NMR). With increasing temperature and humidity, there was a clear degradation of the PLA, which could be reduced or slowed down by adding 50 wt.% starch, due to increased crystallinity. Hydrolysis was identified as the main degradation mechanism for PLA and PLA/starch composites, especially above the glass transition temperature, with thermo-oxidative degradation also playing a subordinate role. Both hydrolytic degradation and thermo-oxidative degradation led to a reduction in mechanical properties such as tensile strength. [ABSTRACT FROM AUTHOR]

Antibody drug conjugates (ADCs) represent one of the fastest growing classes of cancer therapeutics. Drug incorporation through site-specific conjugation in ADCs leads to uniform drug load and distribution. These site-specific modifications may have an impact on ADC quality attributes including protein higher order structure (HOS), which might impact safety and efficacy. In this study, we conducted a side-by-side comparison between the conjugated and unconjugated mAb. In the ADC, the linker-pyrrolobenzodiazepine was site specifically conjugated to an engineered unpaired C215 residue within the F ab domain of the light chain. Differential scanning calorimetry (DSC) and differential scanning fluorimetry (DSF) indicated a decrease in thermal stability for the C H 2 transition of the ADC. Size exclusion chromatography (SEC) analysis showed that conjugation of the mAb resulted in earlier aggregation onset and increased aggregation propensity after 4 weeks at 40 °C. Differential hydrogen-exchange mass spectrometry (HX-MS) indicated that upon conjugation, light chain residues 150-155 and 197-204, close to the conjugation site, showed significantly faster HX kinetics, suggesting an increase in backbone flexibility within this region, while heavy chain residues 32-44 exhibited significantly slower kinetics, suggesting distal stabilization of the mAb backbone. [ABSTRACT FROM AUTHOR]

Glucagon-like peptide-1 (GLP-1) is an incretin hormone that reduces postprandial glycemic excursions by enhancing insulin secretion. In this study, a new dimeric GLP-1 analogue (GLP-1cpGLP-1) was designed by inserting human insulin C -peptide (CP) in the middle of a dimer of [Gly8] GLP-1 (7–36). Then, the dimeric incretin (GLP-1cpGLP-1) was ligated to human αB-crystallin (αB-Cry) to create a hybrid protein, abbreviated as αB-GLP-1cpGLP-1. The constructed gene was well expressed in the bacterial host system. After specific chemical release from the hybrid protein, the dimeric incretin was purified by size exclusion chromatography (SEC). Finally, the RP-HPLC analysis indicated a purity of >99 % for the dimeric incretin. The secondary structure assessments by various spectroscopic methods, and in silico analysis suggested that the dimeric incretin has α-helical rich structure. The dynamic light scattering (DLS) analysis indicates that our dimeric incretin forms large oligomeric structures. This incretin analogue significantly reduced blood glucose levels in both healthy and diabetic mice while effectively triggering insulin release. The size exclusion HPLC also indicates the interaction of the new incretin analogue with human serum albumin, the main carrier protein in the bloodstream. Consistent with the results obtained from the biological activity assessments, this significant interaction indicates its potential as a viable therapeutic agent with a long-lasting effect. The results of our research represent a significant breakthrough in the successful design of an active incretin dimer capable of effectively controlling blood sugar levels and inducing insulin secretion in the realm of diabetes treatment. [Display omitted] • A new incretin dimer containing insulin C -peptide was designed and well produced. • This incretin had a good expression in the bacterial host and high purification efficiency. • The incretin dimer showed an α-helix rich structure with an ability for oligomerization. • It effectively reduced the blood sugar level and stimulated insulin secretion. • The new incretin dimer displays an important potential to be used in the treatment of diabetic patients. [ABSTRACT FROM AUTHOR]

Polyethylene is a plastic pollutant impacting marine life, calling for advanced remediation methods such as biodegradation. However, there is actually limited information on polyethylene-degrading bacteria in the marine environment. Here, we studied bacterial degradation of polyethylene and associated phthalates additives using scanning electron microscopy, Fourier transform infrared, gel permeation chromatography and genomic and transcriptomic techniques. Results show that a deep-sea bacteria, Acinetobacter venetianus F1, can degrade 12.2% of polyethylene after 56 days, following the alkane metabolic pathway. Phthalates were also degraded via the metabolic pathways of benzoic acid and phthalic acid. This is first report of polyethylene-degrading bacteria from deep-sea environments. [ABSTRACT FROM AUTHOR]

At present, controlling the workability of concrete with high clay content sand presents a significant engineering challenge. A novel phosphonate group-modified polycarboxylate superplasticizer (PHS-PCE) was synthesized by using 2-(methacryloyloxy) ethyl phosphate (MOEP), isobutyl alcohol polyoxyethylene ether (IPEG) and acrylic acid (AA). Gel permeation chromatography (GPC), Fourier-transform infrared spectroscopy (FT-IR), 31P nuclear magnetic resonance (31P NMR) spectroscopy and elemental analysis measurements were conducted to characterize the molecular structure of PHS-PCE showing successful incorporation of the phosphonate group with high polymer purity. Despite the relatively low reactivity of MOEP, approximately 65 wt% monomer was incorporated into the copolymer. PHS-PCE exhibited superior flowability and stronger retardation effect than the conventional polycarboxylate superplasticizer (C-PCE), due to the increased negative charge density and enhanced complexing capacity with calcium ion imparted by the phosphonate group. In the presence of clay, the maximum variation of PHS-PCE adsorption on cement particle was 18%, whereas that of C-PCE was 25%. The phosphonate group facilitates adsorption of a portion of PHS-PCE on the clay particle edges, thereby preventing intercalation and improving the clay tolerance. [ABSTRACT FROM AUTHOR]

A novel diphenyl monomer, dimethyl 2,2'-(((ethane-1,2-diylbis(oxy))bis(4-acetyl-3,1-phenylene))bis(oxy))diacetate (EDPD), was synthesized from methyl 2-(4-acetyl-3-hydroxyphenoxy)acetate (MAHA), a 2,4-dihydroxyacetophenonederivative, and combined with 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol or p-phenylenedimethanolto afford a series of biodegradable polyesters via melt polymerization. The polyesters were characterized by Fourier transform infrared and proton nuclear magnetic resonance spectroscopy, gel permeation chromatography, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The weight-average molecular weight (Mw) of the polyesters varied from 3.2–4.4 × 104 g/mol, the glass transition temperature (Tg) from 52 to 80 °C, and the 5% decomposition temperature (Td,5%) was in the 334–362 °C range. All the samples exhibited high yield strength (53–68 MPa) and elongation at break (230–330%) values, comparable with poly(ethylene terephthalate) (PET), owing to their aromatic character. Degradability testing of the polyesters in soil yielded mass losses reaching up to 7% after 32 weeks. In ecotoxicity testing, earthworms had a survival rate of more than 80% after 14 d of incubation, indicating relatively low toxicity. Overall, the good thermal and mechanical properties, biodegradability and low ecotoxicity of the polyesters make them promising materials for packaging applications, in replacement for PET, thereby promoting carbon neutrality and sustainable development. [ABSTRACT FROM AUTHOR]

The worldwide contamination of aquatic ecosystems by plastics is raising concern, including their potential impacts on the base of the food chain, which has been poorly documented. This study sought to examine, for the first time, the presence of nanoplastics (NPs) in biofilms from freshwater streams/rivers. They were collected at selected polluted sites, such as the industrial sector for plastic recycling and production, miscellaneous industries, agriculture, municipal wastewaters/effluents and road runoffs. In parallel, the functional properties of sampled biofilms were determined by proteins, lipids, esterase (lipase), viscosity and oxidative stress. The results revealed that biofilms collected at the plastic industries and road runoffs contained the highest NP levels based on size exclusion chromatography, fluorescence detection and a new nanogold sensor visualization method. Examination of the chromatographic elution profiles showed increased abundance and size of NPs in the 10–150 nm size range at the polluted sites. Biofilms from the plastic industry site had elevated levels of aldehydes (oxidative stress) and lipids compared to the other sites. Biofilms collected at the municipal sites had elevated levels of proteins and esterases/lipases, with a decrease in total lipids. Biofilms collected at agriculture sites had the lowest levels of NPs in this campaign, but more samples would be needed to confirm these trends. In conclusion, biofilms represent an important sink for plastics in freshwater environments and display signs of distress upon oxidative stress. [ABSTRACT FROM AUTHOR]

Nanomedicine is a discipline of medicine that applies all aspects of nanotechnology strategies and concepts for treatment and screening possibilities. Synthetic polymer nanostructures are among the many nanomedicine formulations frequently studied for their potential as vectors. Bioimaging is a valuable diagnostic tool, thus, there is always a demand for new excipients/nanocarriers. In this study, hydrophobic hyperbranched poly(lauryl methacrylate) (PLMA) homopolymers comprised of highly hydrophobic LMA moieties with –COOH polar end groups were synthesized by employing reversible addition-fragmentation chain transfer (RAFT) polymerization. Ethylene glycol dimethacrylate (EGDMA) was utilized as the branching agent. End groups are incorporated through the RAFT agent utilized. The resulting amphiphilic hyperbranched polymer was molecularly characterized by size exclusion chromatography (SEC), Fourier transformation infrared spectroscopy (FT–IR), and 1H–NMR spectroscopy. Pyrene, curcumin, and IR-1048 dye were hydrophobic payload molecules successfully encapsulated to show how adaptable these homopolymer nanoparticles (prepared by nanoprecipitation in water) are as dye nanocarriers. This study demonstrates a simple way of producing excipients by generating polymeric nanoparticles from an amphiphilic, hyperbranched, hydrophobic homopolymer, with a low fraction of polar end groups, for bioimaging purposes. [ABSTRACT FROM AUTHOR]

Until the end of the 70s of the last century, the major tool for fractionating complex polymers regarding molecular size is gel permeation chromatography (GPC) (more accurately size exclusion chromatography, SEC). A milestone in fractionating polymers with regard to chemical composition is achieved when it is shown that random copolymers can be separated according to copolymer composition using solvent gradient HPLC. Another important step toward selective fractionation is taken when liquid chromatography at the critical point of adsorption is introduced as an efficient way to separate functional polymers with regard to their functionality type distribution. Another milestone is the discovery that temperature gradients can also be used for the selective separation of complex polymers with regard to composition. The combination of different LC methods in comprehensive 2D HPLC setups is another milestone. As of today, a toolbox of HPLC methods is in place that enables the fractionation of complex polymers according to all molecular parameters including tacticity and branching. Here, an overview on the different techniques and some major applications is presented. The most important developments in the field are discussed, and different techniques, experimental protocols, and applications are highlighted. In conclusion, challenges for future developments are outlined. [ABSTRACT FROM AUTHOR]

Biodegradable starch-based composite material with bactericidal properties was obtained in this work. The material is promising as environmentally safe food packaging. Native potato starch was modified by graft polymerization of vinyl acetate. The synthesis was carried out in the presence of ammonium persulfate in the alkaline medium under a temperature change mode from 70 to 80 °C. The grafting efficiency was 82% at 91, 5% conversion rate of vinyl acetate. The product of the synthesis is a homogeneous dispersion with an average particle size 2.2∙10–5 cm. The composition and chemical structure of Starch-g-PVAc copolymer were confirmed by extraction, IR spectroscopy and gel permeation chromatography. The films poured from copolymer solution are characterized by 24 MPa of breaking stress and 2.2% of strain. A copolymer-based composition with bactericidal properties was developed by introducing polyhexamethylene guanidine chloride. The composition is biodegradable. Biodegradation of the films under the action of mold fungus Aspergillus niger occurred by 96% in 28 days. The composite based on Starch-g-PVAc + PHMG-ch is promising for use in packaging, cleaning of water environment from contaminants, in medical applications. [ABSTRACT FROM AUTHOR]

Polygonatum sibiricum polysaccharide (PSP) was extracted and purified from raw material obtained from P. sibiricum. The structural features of PSP were investigated by Congo red, circular dichroism spectrum, high‐performance gel permeation chromatography, scanning electron microscope, atomic force microscope, ultraviolet spectroscopy, and Fourier transform infrared spectroscopy analysis. In vitro simulations were conducted to investigate the kinetics of PSP enzyme inhibition. Moreover, a type II diabetes mouse model (T2DM) with streptozotocin‐induced insulin resistance was established, and the indexes of lipid quadruple, insulin resistance index, oral glucose tolerance (OGTT), organ index, and pancreatic morphology of model mice were measured. The results showed that PSP mainly consists of monosaccharides, such as mannose, glucose, galactose, xylose, and arabinose. It also has a β‐glycosidic bond of a pyranose ring and an irregular reticulated aggregated structure with a triple helix. In vitro enzyme inhibition assays revealed that PSP acts as a reversible competitive inhibitor of α‐glucosidase and α‐amylase. Furthermore, PSP was found to reduce insulin resistance index, increase OGTT and serum insulin levels, decrease free fatty acid content to improve lipid metabolism, and lower glycated serum protein content to enhance glucose metabolism in T2DM mice, thereby leading to a reduction in blood glucose concentration. Additionally, PSP exhibited reparative effects on the damaged liver tissue cells and pancreatic tissue in T2DM mice. The experiment results provide a preliminary basis for the therapeutic mechanism of PSP about type II diabetes and a theoretical reference for application in food and pharmaceutical development. [ABSTRACT FROM AUTHOR]

The α-1,3-glucanase Agl-EK14 from Flavobacterium sp. EK-14 comprises a signal peptide (SP), a catalytic domain (CAT), a first immunoglobulin-like domain (Ig1), a second immunoglobulin-like domain (Ig2), a ricin B-like lectin domain (RicinB), and a carboxy-terminal domain (CTD). SP and CTD are predicted to be involved in extracellular secretion, while the roles of Ig1, Ig2, and RicinB are unclear. To clarify their roles, domain deletion enzymes Agl-EK14ΔRicinB, Agl-EK14ΔIg2RicinB, and Agl-EK14ΔIg1Ig2RicinB were constructed. The insoluble α-1,3-glucan hydrolytic, α-1,3-glucan binding, and fungal cell wall hydrolytic activities of the deletion enzymes were almost the same and lower than those of Agl-EK14. Kinetic analysis revealed that the K m values of the deletion enzymes were similar and uniformly higher than those of Agl-EK14. These results suggest that the deletion of RicinB causes a decline in binding and hydrolytic activity and increases the K m value. To confirm the role of RicinB, Ig1, Ig2, and RicinB were fused with green fluorescent protein (GFP). As a result, RicinB-fused GFP (GFP-RicinB) showed binding to insoluble α-1,3-glucan and Aspergillus oryzae cell walls, whereas Ig1- and Ig2-fused GFP did not. These results indicated that RicinB is involved in α-1,3-glucan binding. The fusion protein GFP-Ig1Ig2RicinB was also constructed and GFP-Ig1Ig2RicinB showed strong binding to the cell wall of A. oryzae compared to GFP-RicinB. Gel filtration column chromatography suggested that the strong binding was due to GFP-Ig1Ig2RicinB loosely associated with itself. [ABSTRACT FROM AUTHOR]

The respiratory syncytial virus (RSV) M2-1 protein is a transcriptional antitermination factor crucial for efficiently synthesizing multiple full-length viral mRNAs. During RSV infection, M2-1 exists in a complex with mRNA within cytoplasmic compartments called inclusion body-associated granules (IBAGs). Prior studies showed that M2-1 can bind along the entire length of viral mRNAs instead of just gene-end (GE) sequences, suggesting that M2-1 has more sophisticated RNA recognition and binding characteristics. Here, we analyzed the higher oligomeric complexes formed by M2-1 and RNAs in vitro using size exclusion chromatography (SEC), electrophoretic mobility shift assays (EMSA), negative stain electron microscopy (EM), and mutagenesis. We observed that the minimal RNA length for such higher oligomeric assembly is about 14 nucleotides for polyadenine sequences, and longer RNAs exhibit distinct RNA-induced binding modality to M2-1, leading to enhanced particle formation frequency and particle homogeneity as the local RNA concentration increases. We showed that particular cysteine residues of the M2-1 cysteine-cysteine-cystine-histidine (CCCH) zinc-binding motif are essential for higher oligomeric assembly. Furthermore, complexes assembled with long polyadenine sequences remain unaffected when co-incubated with ribonucleases or a zinc chelation agent. Our study provided new insights into the higher oligomeric assembly of M2-1 with longer RNA. IMPORTANCE Respiratory syncytial virus (RSV) causes significant respiratory infections in infants, the elderly, and immunocompromised individuals. The virus forms specialized compartments to produce genetic material, with the M2-1 protein playing a pivotal role. M2-1 acts as an anti-terminator in viral transcription, ensuring the creation of complete viral mRNA and associating with both viral and cellular mRNA. Our research focuses on understanding M2-1’s function in viral mRNA synthesis by modeling interactions in a controlled environment. This approach is crucial due to the challenges of studying these compartments in vivo. Reconstructing the system in vitro uncovers structural and biochemical aspects and reveals the potential functions of M2-1 and its homologs in related viruses. Our work may contribute to identifying targets for antiviral inhibitors and advancing RSV infection treatment. [ABSTRACT FROM AUTHOR]

The molecular weight, surface tension, and the particle size distribution of micellar aggregates of a polyetherpolyacrylate polymeric surfactant, HS-PA, were characterized on gel permeation chromatograph, surface tension meter, and laser particle size analyzer, respectively. The thickening properties, detergency, liquid crystal morphology, suspension properties, and rheological behaviors of HS-PA in unstructured/structured detergents with LAS/AES/AEO9 as the main surfactants, respectively, were also investigated. The characterization results showed that, the weight-average molecular weight of HS-PA was 4 244, the critical micelle concentration was 3x10-7 mol/L, and the equilibrium surface tension was 42.06 mN/m; the average particle size of aggregates was increased when LAS, AES and AEO9 formed mixed micelles with HS-PA, respectively. The application test in unstructured detergents showed that, HS-PA had viscosityenhancing effects on all the LAS/AES/AEO9-based systems, and meanwhile it was beneficial to the improvement of the detergency to sebum. The application test in structured detergents showed that, HS-PA would help the formation of lamellar liquid crystals in the LAS/AES/AEO9 systems, and the more HS-PA used, the more the liquid crystals in the AES system; the centrifugal separation results showed that the structured detergents containing HS-PA had the ability to stabilize the suspension of microcapsules; HS-PA could increase the yield stress of the LAS formulation system as determined by rotational rheometer. [ABSTRACT FROM AUTHOR]

RG-I pectin has excellent health benefits, but its raw materials are relatively scarce, and its complex structure often breaks down its side-chain structure during the extraction process. In this study, the physicochemical and antioxidant properties of a branched-chain-rich pectin gained from watermelon peel were demonstrated, and the structure–function relationships of RG-I-enriched pectin and emulsification properties were investigated. Fourier transform infrared spectroscopy, high-performance anion exchange chromatography, high-performance gel permeation chromatography, nuclear magnetic resonance spectroscopy, and methylation analyses reveal it as acetylated, low-methoxylated pectin, rich in RG-I side chains (MW: 1991 kDa, RG-I = 66.17%, methylation degree: 41.45%, (Ara + Gal)/Rha: 20.59%). RPWP outperforms commercial citrus pectin in emulsification and stability, significantly preventing lipid oxidation in emulsions. It also exhibits free radical scavenging abilities, contributing to its effectiveness in preventing lipid oxidation. Emulsions made with RPWP show higher viscosity and form a weak gel network (G′ > G″), enhancing stability by preventing phase separation. These findings position watermelon peel as a good source of RG-I pectin and deepen our understanding of RPWP behavior in emulsion systems, which may be useful in the food and pharmaceutical fields. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To improve melt strength and toughness of polyamide 6 (PA6), an on‐line UV radiation method is introduced into reaction extrusion to induce free radical reaction for efficient preparation of long‐chain branched PA6 materials. Trimethylolpropane triacrylate and glycidyl methacrylate are adopted as chain extenders to synergistically introduce long‐chain branches onto PA6 macromolecules. Gel permeation chromatography results show the increase of molecular weight of PA6, implying the successful graft of chain extenders onto molecular chains. Based on rheological measurement results, modified PA6 exhibits better melt strength than pure PA6 owing to a larger storage modulus. The elongation at break and impact strength of modified PA6 at T1G1 are about 5.3 and 2.2 times those of pure PA6, respectively, without sacrificing tensile strength. According to Fourier transform infrared spectroscopy results, we propose reaction mechanisms between trimethylolpropane triacrylate/glycidyl methacrylate and PA6 under on‐line UV radiation. This study offers a practical approach for the efficient preparation of long‐chain branched PA6, thereby broadening the potential applications of the material. Highlights: An on‐line UV radiation method is introduced into reaction extrusion.The melt strength and toughness of polyamide 6 are realized simultaneously at low cost.The synergistic effect mechanism of trimethylolpropane triacrylate and glycidyl methacrylate is proposed.Provides a feasible way to efficiently prepare long‐chain branched polyamide 6. [ABSTRACT FROM AUTHOR]

This study investigates the reinforcement of pluronic (PF127) based temperature responsive hydrogels with photosensitive functionalities to create smart and injectable materials. For this purpose, 4‐[4‐[(4‐phenyl)azo]phenoxy] methacrylate (PAzPMA) was synthesized and further polymerized via reversible addition‐fragmentation chain transfer (RAFT) polymerization. The structures of the copolymers were characterized by several techniques such as Fourier‐transform infrared (FT‐IR), nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC). The azobenzene‐functionalized copolymer was combined with P127 solid polymer in micelle form and with P127 micelles in solid form to obtain PF127‐AzoMx and PF127‐AzoPx gels, respectively. When the temperature profiles of the PF127‐AzoMx and PF127‐AzoPx systems were compared with PF127, sol–gel phase transition were shifted to lower temperatures due to stronger hydrophobic interactions. Additionally, different concentrations of N,N,N‐trimethyl chitosan (f‐chitosan) were added to the gel systems and their rheological properties were investigated by exposing them to UV light. It has been observed that the presence and concentration of f‐chitosan are important for the variation of the interactions' strength between the micelles. The study highlights the potential of multifunctional hydrogels for specific biomedical applications that combine sensitivity to both thermal and optical stimuli for controlled drug delivery and tissue engineering purposes. [ABSTRACT FROM AUTHOR]

Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The prevalent life-threatening microbial and cancer diseases and lack of effective pharmaceutical therapies created the need for new molecules with antimicrobial and anticancer potential. Bee venom (BV) was collected from honeybee workers, and melittin (NM) was extracted from BV and analyzed by urea-polyacrylamide gel electrophoresis (urea-PAGE). The isolated melittin was hydrolyzed with alcalase into new bioactive peptides and evaluated for their antimicrobial and anticancer activity. Gel filtration chromatography fractionated melittin hydrolysate (HM) into three significant fractions (F1, F2, and F3), that were characterized by electrospray ionization mass spectrometry (ESI-MS) and evaluated for their antimicrobial, anti-biofilm, antitumor, and anti-migration activities. All the tested peptides showed antimicrobial and anti-biofilm activities against Gram-positive and Gram-negative bacteria. Melittin and its fractions significantly inhibited the proliferation of two types of cancer cells (Huh-7 and HCT 116). Yet, melittin and its fractions did not affect the viability of normal human lung Wi-38 cells. The IC50 and selectivity index data evidenced the superiority of melittin peptide fractions over intact melittin. Melittin enzymatic hydrolysate is a promising novel product with high potential as an antibacterial and anticancer agent. [ABSTRACT FROM AUTHOR]

The purpose of this study was to develop a formulation for a recombinant prefusion spike protein vaccine against SARS-CoV-2. It was found that the spike protein was susceptible to aggregation due to mechanical stress. Therefore, formulation studies were initiated focused on screening pharmaceutical excipients capable of preventing this. The screening of a panel of potential stabilizing conditions found that Tween 20 could inhibit mechanically induced aggregation. A concentration-dependent study indicated that a higher concentration of Tween 20 (0.2% v/v) was required to prevent conformational changes in the trimer. The conformational changes induced by mechanical stress were characterized by size exclusion chromatography (SEC) and hydrogen–deuterium exchange mass spectrometry (HDX-MS), indicating the formation of an extended trimeric conformation that was also unable to bind to antibodies directed to the S2 domain. Long-term stability modeling, using advanced kinetic analysis, indicated that the formulation containing 0.2% (v/v) Tween 20 at a neutral pH was predicted to be stable for at least two years at 2 °C to 8 °C. Additional stabilizer screening conducted by thermal shift assay indicated that sucrose and glycerol were able to significantly increase the spike protein melting temperature (Tm) and improve the overall thermostability of the spike protein in a short-term stability study. Thus, while 0.2% (v/v) Tween 20 was sufficient to prevent aggregation and to maintain spike protein stability under refrigeration, the addition of sucrose further improved vaccine thermostability. Altogether, our study provides a systematic approach to the formulation of protein-based COVID-19 vaccine and highlights the impact of mechanical stress on the conformation of the spike protein and the significance of surfactants and stabilizers in maintaining the structural and functional integrity of the spike protein. [ABSTRACT FROM AUTHOR]

Two soy protein 11S fractions with different surface sulfhydryl contents were prepared. Utilizing analytical ultracentrifugation, the effects of storage time and hydrogen peroxide at different concentrations (0.5—100 mmol/L) on the two 11S fractions were investigated. Results show that after removing 2-mercaptoethanol (2-ME) by size exclusion chromatography, the 11S fraction with high surface sulfhydryl content (2.0 mol sulfhydryl/mol 11S) progressively formed 15S and 21S in dilute solutions during storage at 4 °C for 82 days. While, the 11S fraction with low surface sulfhydryl content (0.2 mol sulfhydryl/mol 11S) was stable under the same condition. Moreover, after treating the 11S with high surface sulfhydryl content with 1 mmol/L H2O2, the weight percentage of 15S reached the maximum value of 20%. The 15S induced by air and H2O2 could be totally converted to 11S with the addition of 10 mmol/L 2-ME, which could be attributed to that the disulfide bond linking two 11S molecules is on the surface of the 15S and easily accessible to the reducing agent 2-ME. This study helps us to deeply understand the formation mechanism of 15S and the stability of 11S. [ABSTRACT FROM AUTHOR]

Background: This study aimed to assess Pseudomonas fluorescens-purified L-Asparaginase's effectiveness as a broad-spectrum inhibitor of biofilm producers in dental decays. Methods: The 16S rRNA sequence was used to build a phylogenetic tree to calculate the evolutionary distance between the isolated bacterial strain SW3 and other species. The evolutionary history was inferred by using the neighbor-joining approach. Results: The bacteria were identified from dental decays, including Staphylococcus aureus, Streptococcus mutans, Streptococcus oralis, and Streptococcus mitis. Each one of these isolates showed different degrees of biofilm development. Purified L-Asparaginase inhibited the most potent Gram-positive biofilm-forming bacteria (biofilm producers) with higher inhibition percentages against Streptococcus oralis and Streptococcus mitis, 65 - 73.8 % and 54.7 - 63%, respectively. The inhibition percentages increased with increasing concentration and reached up to 74 - 81% with Streptococcus oralis and 66 - 74% with Streptococcus mitis, while SW3 bacteria showed (100%). This strain was suggested SW3 (Pseudomonas spp.). Pseudomonas fluorescens bacterial strain isolated from rhizosphere soil produced extracellular L-Asparaginase when grown on as a substrate. L-Asparaginase was purified to homogeneity by using ammonium sulfate at 60% saturation, followed by gel filtration chromatography on a sephadex G-100 column, with a recovery yield of 49% and a purification fold of 2.22. Conclusions: L-Asparaginase had a promising use for removing and avoiding biofilm growth, implying that it might be used in the dental industry in the future. [ABSTRACT FROM AUTHOR]

Background Results Conclusion Peanut peptides can chelate iron but their chelation mechanism remains unclear. The purpose of this study is to separate peanut ferrous‐chelating peptides and explore the chelation mechanism of peanut peptides with iron.Peanut peptide component F‐122, which had a higher chelation rate, was separated using ultrafiltration, gel filtration chromatography, and ion exchange chromatography, achieving a ferrous chelation rate of 90.7%. Six peptide segments were screened and their amino acid sequences were identified by liquid chromatography–tandem mass spectrometry (LC–MS/MS). Spectral analysis confirmed that the chelation between peanut peptides and ferrous ions occurred and a new substance was formed. Molecular docking simulation indicated that the amino acids in peanut peptides involved in the chelating reaction were glutamic acid, arginine, glycine, threonine, phenylalanine, and lysine. The binding sites included the main chain oxygen atom, side chain oxygen atom, and carboxyl oxygen atom of amino acid.The isolated peanut peptide had a higher ferrous‐chelation rate. The chelating mechanism of peanut peptide with ferrous ion was elucidated. This study provides a theoretical basis for the development of new peptide‐ferrous preparations. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Objective: Extracellular vesicles (EVs) have been shown to play a critical role in promoting tumorigenesis. As EV research grows, it is of importance to have standardization of isolation, quality control, characterization and validation methods across studies along with reliable references to explore troubleshooting solutions. Therefore, our objective with this Research Note was to isolate EVs from multiple breast cancer cell lines and to describe and perform protocols for validation as outlined by the list of minimal information for studies of EVs (MISEV) from the International Society for Extracellular Vesicles. Results: To isolate EVs, two techniques were employed: ultracentrifugation and size exclusion chromatography. Ultracentrifugation yielded better recovery of EVs in our hands and was therefore used for further validation. In order to satisfy the MISEV requirements, protein quantification, immunoblotting of positive (CD9, CD63, TSG101) and negative (TGFβ1, β-tubulin) markers, nanoflow cytometry and electron microscopy was performed. With these experiments, we demonstrate that yield of validated EVs varied between different breast cancer cell lines. Protocols were optimized to accommodate for low levels of EVs, and various technical and troubleshooting suggestions are included for potential application to other cell types that may provide benefit to investigators interested in future EV studies. [ABSTRACT FROM AUTHOR]