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Background: Pseudomonas aeruginosa (PA) is an opportunistic pathogen that can cause sight threatening infections in the eye and fatal infections in the cystic fibrosis airway. Extracellular vesicles (EVs) are released by host cells during infection and by the bacteria themselves; however, there are no studies on the composition and functional role of host-derived EVs during PA infection of the eye or lung. Here we investigated the composition and capacity of EVs released by PA infected epithelial cells to modulate innate immune responses in host cells. Methods: Human telomerase immortalized corneal epithelial cells (hTCEpi) cells and human telomerase immortalized bronchial epithelial cells (HBECs) were treated with a standard invasive test strain of Pseudomonas aeruginosa, PAO1, for 6 h. Host derived EVs were isolated by qEV size exclusion chromatography. EV proteomic profiles during infection were compared using mass spectrometry and functional studies were carried out using hTCEpi cells, HBECs, differentiated neutrophil-like HL-60 cells, and primary human neutrophils isolated from peripheral blood. Results: EVs released from PA infected corneal epithelial cells increased pro-inflammatory cytokine production in naïve corneal epithelial cells and induced neutrophil chemotaxis independent of cytokine production. The EVs released from PA infected bronchial epithelial cells were also chemotactic although they failed to induce cytokine secretion from naïve HBECs. At the proteomic level, EVs derived from PA infected corneal epithelial cells exhibited lower complexity compared to bronchial epithelial cells, with the latter having reduced protein expression compared to the non-infected control. Conclusions: This is the first study to comprehensively profile EVs released by corneal and bronchial epithelial cells during Pseudomonas infection. Together, these findings show that EVs released by PA infected corneal and bronchial epithelial cells function as potent mediators of neutrophil migration, contributing to the exuberant neutrophil response that occurs during infection in these tissues. [ABSTRACT FROM AUTHOR]

For polymer recycling research, consistent polymer substrates sourced from widely available vendors are useful to enable direct comparisons between studies. Additionally, when reporting new recycling approaches, it is essential to characterize polymer chemical composition, physical properties, structure, and the presence of additives. Here we characterized 59 polymers from common commercial vendors across 20 different polymer classes, representing >95% of global plastic production by mass. Structural characterization was conducted with gel permeation chromatography, Fourier-transform infrared spectroscopy, and small and wide-angle X-ray scattering, and bulk characterization included CHNS measurements and elemental analysis by inductively coupled plasma mass spectrometry (ICP-MS). Thermal properties were measured using differential scanning calorimetry (DSC) and thermal gravimetric analysis. Nearly all plastics studied contained inorganic and organic additives, including halogens, sulfur-containing compounds, and antioxidants, which were investigated by either ICP-MS, accelerated solvent extraction followed by gas chromatography-mass spectrometry (GC-MS), pyrolysis GC-MS and high-resolution GC-MS. In general, the polymers vary from what they were reported to be, with 5 polymers exhibiting molar mass distributions different from that provided by vendors, 6 polymers exhibiting bimodal molecular mass distributions, and 10 polymers displaying unexpected thermal properties measured by DSC including multiple glass transitions and unusual exotherms. Finally, we also investigated changes in properties pre- and post-cryomilling, a common preprocessing technique in recycling studies. Here we found that 16 polymers had changes in either the average molecular mass, dispersity, or percent crystallinity after cryomilling. Taken together, this study further highlights the need to conduct thorough characterization on polymer substates while also providing a baseline analytical characterization for widely available research plastics. We have further made all data available through an online database. [ABSTRACT FROM AUTHOR]

Background: The lack of standardized protocols for isolating extracellular vesicles (EVs), especially from biobank-stored blood plasma, translates to limitations for the study of new biomarkers. This study examines whether a combination of current isolation methods could enhance the specificity and purity of isolated EVs for diagnosis and personalized medicine purposes. Results: EVs were isolated from healthy human plasma stored for one year by ultracentrifugation (UC), size exclusion chromatography (SEC), or SEC and UC combined (SEC + UC). The EV isolates were then characterized by transmission electron microscopy imaging, nanoparticle tracking analysis (NTA) and western blotting. Proteomic procedures were used to analyze protein contents. The presence of EV markers in all isolates was confirmed by western blotting yet this analysis revealed higher albumin expression in EVs-UC, suggesting plasma protein contamination. Proteomic analysis identified 542 proteins, SEC + UC yielding the most complex proteome at 364 proteins. Through gene ontology enrichment, we observed differences in the cellular components of EVs and plasma in that SEC + UC isolates featured higher proportions of EV proteins than those derived from the other two methods. Analysis of proteins unique to each isolation method served to identify 181 unique proteins for the combined approach, including those normally appearing in low concentrations in plasma. This indicates that with this combined method, it is possible to detect less abundant plasma proteins by proteomics in the resultant isolates. Conclusions: Our findings reveal that the SEC + UC approach yields highly pure and diverse EVs suitable for comprehensive proteomic analysis with applications for the detection of new biomarkers in biobank-stored plasma samples. [ABSTRACT FROM AUTHOR]

A series of rigid polystyrene‐based photoelastomers, named sty‐PM‐x, with bionic catechol pendants were synthesized through atom transfer radical polymerization (ATRP) and deprotection techniques. These polymers were characterized using nuclear magnetic resonance spectroscopy, gel permeation chromatography, and thermogravimetric analysis. Additionally, photophysical properties of the polymers were investigated using UV‐visible absorption spectroscopy and fluorescence emission spectroscopy. Mechanical properties were evaluated through tensile tests, while interfacial adhesion was determined through cross‐cut tests. Experimental results reveal that photoelastomers, sty‐PM‐x, exhibit excellent photophysical properties, stretchability, and interfacial adhesion. This discovery provides a new perspective for the preparation of stretchable organic electroluminescent materials. [ABSTRACT FROM AUTHOR]

This correction notice addresses errors in Figures 2, 3, and S3 of the article titled "Dynein and Dynactin Leverage Their Bivalent Character to Form a High-Affinity Interaction." The correction provides updated versions of the figures to address the issues. The corresponding author stated that the individual-level quantitative data underlying the article are no longer available. The authors acknowledge the errors, apologize, and are grateful for the opportunity to correct them. [Extracted from the article]

A versatile and robust end‐group derivatization approach using oximes has been developed for the detection of oxidative degradation of synthetic polyisoprenes and polybutadiene. This method demonstrates broad applicability, effectively monitoring degradation across a wide molecular weight range through ultraviolet (UV)‐detection coupled to gel permeation chromatography. Importantly, it enables the effective monitoring of degradation via derivatization‐induced UV‐maximum shifts, even in the presence of an excess of undegraded polyene, overcoming limitations previously reported with refractive index detectors. Notably, this oxime‐based derivatization methodology is used in enzymatic degradation experiments of synthetic polyisoprenes characterized by a cis: trans ratio with the rubber oxygenase LcpK30. It reveals substantial UV absorption in derivatized enzymatic degradation products of polyisoprene with molecular weights exceeding 1000 g mol−1 ‐ an unprecedented revelation for this enzyme's activity on such synthetic polyisoprenes. This innovative approach holds promise as a valuable tool for advancing research into the degradation of synthetic polyisoprenes and polybutadiene, particularly under conditions of low organocatalytic or enzymatic degradation activity. With its broad applicability and capacity to reveal previously hidden degradation processes, it represents a noteworthy contribution to sustainable polymer chemistry. [ABSTRACT FROM AUTHOR]

In this study, Schiff bases (SCH-1 and SCH-2) were synthesized from the condensation reaction of 2-aminobenzothiazole with 3-hydroxy-4-methoxybenzaldehyde and 3-hydroxy-4-ethoxybenzaldehyde. Poly(phenoxy-imine)s were synthesized from Schiff bases via oxidative polycondensation by NaOCl (6–14% aqueous solution) as oxidant in alkaline medium and H2O2 (35% aqueous solution) as oxidant in THF medium. The structures characterizations of Schiff bases and poly(phenoxy-imine)s were confirmed by FT-IR, 1H and 13C NMR, CV, UV–Vis and TGA analyses. Limit oxygen index (LOI) and the heat resistance index (THRI) temperature were determined from thermogravimetric measurements of compounds. P-SCH-2-A showed the highest LOI as 45.50 with self-extinguishing according to other polymers (18–30). The optical band gap of P-SCH-2-A was determined to be 1.99 eV. Additionally, the optical band gap energy of compounds were calculated by using the Tauc method. According to the Tauc method, the optical band gap (Eg) value of P-SCH-2-A was calculated to be 2.20 eV. The glass transition temperatures (Tg) and surface properties of poly(phenoxy-imine)s were determined from DSC and SEM analyses, respectively. The weight average molecular weight (Mw) values of P-SCH-1-O, P-SCH-2-O, P-SCH-1-A and P-SCH-2-A were calculated to be 7400, 8400, 3100 and 19,100 g mol−1 from gel permeation chromatography (GPC) measurements. [ABSTRACT FROM AUTHOR]

UV debonding acrylate pressure-sensitive adhesives (UPSAs) are necessarily applied in the semiconductor industry. To establish a comprehensively understood method is important to detect their bonding and debonding behaviors. In this paper, rheological methods, including Three Interval Thixotropy tests (3ITT) and Tack test modes were used for characterizing series of UPSAs. Vinyl groups were successfully grafted onto the acrylate copolymer chains through isocyanate condensation reactions, which were characterized by nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy and gel permeation chromatography. From the maximum normal force in the Tack test modes, UPSAs after UV irradiation showed obvious debonding behaviors in short-time stress analysis. The recovery percentage of the storage modulus in 3ITT tests indicated that 0.6 wt% isocyanate curing agent made the UPSAs good resistance to deformation. Under the limit of 30 wt% pentaerythritol diacrylate (PETA), the rheological adhesion performance of UPSAs increases accordingly with the PETA content, which was also confirmed by 180° peel strength tests. From the microscope images of the wafer surfaces after peeling off the UPSA tapes, rheological characterization methods can help designing UPSAs with clean debonding properties. [ABSTRACT FROM AUTHOR]

With the global population on the rise, an escalating interest exists in environmentally sustainable and friendly protein sources. Insects have emerged as multifaceted resources, viewed not only as potential food items, but also as sources of traditional medicines and proteins. This study utilized response surface methodology (RSM) to ascertain the optimal extraction conditions for proteins from Musca domestica used in toad feeding, denoted as MDPs-T. The yield of MDPs-T was elevated to 18.3% ± 0.2% under these optimized conditions. Subsequently, the particle size, ζ-potentials, and structures of MDPs-T were analyzed and compared with the proteins derived from Musca domestica fed on a normal diet (MDPs-ND). This comparative analysis utilized a range of advanced techniques, involving UV spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), high-performance gel permeation chromatography (HPGPC), and scanning electron microscopy (SEM). The outcomes have revealed a marginal disparity in the physical and chemical properties between MDPs-T and MDPs-ND. Derosination led to a reduction in the particle size of the MDPs by 10.98% to 62.81%. MDPs-T exhibited a higher proportion of low-molecular-weight components relative to MDPs-ND. Additionally, in a comparative analysis of amino acids, MDPs-T displayed a greater abundance of essential and total amino acids relative to MDPs-ND. Consequently, MDPs-T holds potential as a valuable food supplement for human consumption or as a nutrient-rich feed supplement for animals. [ABSTRACT FROM AUTHOR]

In order to contribute to the shift from petro-based chemistry to biobased chemistry, necessary to minimize the environmental impacts of the chemical industry, 2-methoxy-4-vinylphenol (4-vinyl guaiacol, 4VG) was used to synthesize a platform of biobased monomers. Thus, nine biobased monomers were successfully prepared. The synthesis procedures were investigated through the green metrics calculations in order to quantify the sustainability of our approaches. Their radical homopolymerization in toluene solution initiated by 2,2′-azobis(2-methylpropionitrile) (AIBN) was studied and the effect of residual 4VG as a radical inhibitor on the kinetics of polymerization was also explored. The new homopolymers were characterized by proton nuclear magnetic resonance (1H-NMR) spectroscopy, size exclusion chromatography and thermal analyses (dynamical scanning calorimetry DSC, thermal gravimetric analysis TGA). By varying the length of the alkyl ester or ether group of the 4VG derivatives, homopolymers with Tg ranging from 117 °C down to 5 °C were obtained. These new biobased monomers could be implemented in radical copolymerization as substitutes to petro-based monomers to decrease the carbon footprint of the resulting copolymers for various applications. [ABSTRACT FROM AUTHOR]

Biopharmaceutical products, in particular messenger ribonucleic acid (mRNA), have the potential to dramatically improve the quality of life for patients suffering from respiratory and infectious diseases, rare genetic disorders, and cancer. However, the quality and safety of such products are particularly critical for patients and require close scrutiny. Key product-related impurities, such as fragments and aggregates, among others, can significantly reduce the efficacy of mRNA therapies. In the present work, the possibilities offered by size exclusion chromatography (SEC) for the characterization of mRNA samples were explored using state-of-the-art ultra-wide pore columns with average pore diameters of 1000 and 2500 Å. Our investigation shows that a column with 1000 Å pores proved to be optimal for the analysis of mRNA products, whatever the size between 500 and 5000 nucleotides (nt). We also studied the influence of mobile phase composition and found that the addition of 10 mM magnesium chloride (MgCl2) can be beneficial in improving the resolution and recovery of large size variants for some mRNA samples. We demonstrate that caution should be exercised when increasing column length or decreasing the flow rate. While these adjustments slightly improve resolution, they also lead to an apparent increase in the amount of low-molecular-weight species (LMWS) and monomer peak tailing, which can be attributed to the prolonged residence time inside the column. Finally, our optimal SEC method has been successfully applied to a wide range of mRNA products, ranging from 1000 to 4500 nt in length, as well as mRNA from different suppliers and stressed/unstressed samples. [ABSTRACT FROM AUTHOR]

In the last few years, several studies have emphasized the existence of injury-specific EV "barcodes" that could have significant importance for the precise diagnosis of different organ injuries in polytrauma patients. To expand the research potential of the NTF (network trauma research) biobank of polytraumatized patients, the NTF research group decided to further establish a biobank for EVs. However, until now, the protocols for the isolation, characterization, and storage of EVs for biobank purposes have not been conceptualized. Plasma and serum samples from healthy volunteers (n = 10) were used. Three EV isolation methods of high relevance for the work with patients' samples (ultracentrifugation, size exclusion chromatography, and immune magnetic bead-based isolation) were compared. EVs were quantified using nanoparticle tracking analysis, EV proteins, and miRNAs. The effects of different isolation solutions; the long storage of samples (up to 3 years); and the sensibility of EVs to serial freezing–thawing cycles and different storage conditions (RT, 4/−20/−80 °C, dry ice) were evaluated. The SEC isolation method was considered the most suitable for EV biobanking. We did not find any difference in the quantity of EVs between serum and plasma-EVs. The importance of particle-free PBS as an isolation solution was confirmed. Plasma that has been frozen for a long time can also be used as a source of EVs. Serial freezing–thawing cycles were found to affect the mean size of EVs but not their amount. The storage of EV samples for 5 days on dry ice significantly reduced the EV protein concentration. [ABSTRACT FROM AUTHOR]

In the hydrogenotrophic methanogenic pathway, formylmethanofuran dehydrogenase (Fmd) catalyzes the formation of formylmethanofuran through reducing CO2. Heterodisulfide reductase (Hdr) provides two low potential electrons for the Fmd reaction using a flavin‐based electron‐bifurcating mechanism. [NiFe]‐hydrogenase (Mvh) or formate dehydrogenase (Fdh) complexes with Hdr and provides electrons to Hdr from H2 and formate, or the reduced form of F420, respectively. Recently, an Fdh‐Hdr complex was purified as a 3‐MDa megacomplex that contained Fmd, and its three‐dimensional structure was elucidated by cryo‐electron microscopy. In contrast, the Mvh‐Hdr complex has been characterized only as a complex without Fmd. Here, we report the isolation and characterization of a 1‐MDa Mvh‐Hdr‐Fmd megacomplex from Methanothermobacter marburgensis. After anion‐exchange and hydrophobic chromatography was performed, the proteins with Hdr activity eluted in the 1‐ and 0.5‐MDa fractions during size exclusion chromatography. Considering the apparent molecular mass and the protein profile in the fractions, the 1‐MDa megacomplex was determined to be a dimeric Mvh‐Hdr‐Fmd complex. The megacomplex fraction contained a polyferredoxin subunit MvhB, which contains 12 [4Fe‐4S]‐clusters. MvhB polyferredoxin has never been identified in the previously purified Mvh‐Hdr and Fmd preparations, suggesting that MvhB polyferredoxin is stabilized by the binding between Mvh‐Hdr and Fmd in the Mvh‐Hdr‐Fmd complex. The purified Mvh‐Hdr‐Fmd megacomplex catalyzed electron‐bifurcating reduction of [13C]‐CO2 to form [13C]‐formylmethanofuran in the absence of extrinsic ferredoxin. These results demonstrated that the subunits in the Mvh‐Hdr‐Fmd megacomplex are electronically connected for the reduction of CO2, which likely involves MvhB polyferredoxin as an electron relay. [ABSTRACT FROM AUTHOR]

In this study, we purified a lectin isolated from the seeds of Dioclea bicolor (DBL) via affinity purification. Electrophoresis analysis revealed that DBL had three bands, α, β, and γ chains, with molecular masses of approximately 29, 14, and 12 kDa, respectively. Gel filtration chromatography revealed that the native form of DBL had a molecular mass of approximately 100 kDa, indicating that it is a tetramer. Interestingly, DBL-induced hemagglutination was inhibited by several glucosides, mannosides, ampicillin, and tetracycline with minimum inhibitory concentration (MIC) values of 1.56–50 mM. Analysis of the complete amino acid sequence of DBL revealed the presence of 237 amino acids with high similarity to other Diocleinae lectins. Circular dichroism showed the prominent β-sheet secondary structure of DBL. Furthermore, DBL structure prediction revealed a Discrete Optimized Protein Energy (DOPE) score of –26,642.69141/Normalized DOPE score of –1.84041. The DBL monomer was found to consist a β-sandwich based on its 3D structure. Molecular docking showed the interactions between DBL and α-D-glucose, N-acetyl-D-glucosamine, α-D-mannose, α-methyl-D-mannoside, ampicillin, and tetracycline. In addition, DBL showed antimicrobial activity with an MIC of 125 μg/mL and exerted synergistic effects in combination with ampicillin and tetracycline (fractional inhibitory concentration index ≤ 0.5). Additionally, DBL significantly inhibited biofilm formation and showed no toxicity in murine fibroblasts (p < 0.05). These results suggest that DBL exhibits antimicrobial activity and works synergistically with antibiotics. [ABSTRACT FROM AUTHOR]

Arabinogalactan (AG), extracted from larch wood, is a β-1,3-galactan backbone and β-1,6-galactan side chains with attached α-1-arabinofuranosyl and β-1-arabinopyranosyl residues. Although the structural characteristics of arabinogalactan II type have already been studied, its functionalization using 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) oxidation remains a promising avenue. In this study, the oxidation of AG, a neutral polysaccharide, was carried out using the TEMPO/NaBr/NaOCl system, resulting in polyuronides with improved functional properties. The oxidation of AG was controlled by analyzing portions of the reaction mixture using spectrophotometric and titration methods. To determine the effect of the TEMPO/NaBr/NaOCl system, air-dried samples of native and oxidized AG were studied by Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy, as well as by gel permeation chromatography. Compounds that model free (1,1-diphenyl-2-picrylhydrazyl (DPPH)) and hydroxyl radicals (iron(II) sulfate, hydrogen peroxide, and salicylic acid) were used to study the antioxidant properties. It was found that, in oxidized forms of AG, the content of carboxyl groups increases by 0.61 mmol compared to native AG. The transformation of oxidized AG into the H+ form using a strong acid cation exchanger leads to an increase in the number of active carboxyl groups to 0.76 mmol. Using FTIR spectroscopy, characteristic absorption bands (1742, 1639, and 1403 cm−1) were established, indicating the occurrence of oxidative processes with a subsequent reduction in the carboxyl group. The functionality of AG was also confirmed by gel permeation chromatography (GPC), which is reflected in an increase in molecular weights (up to 15,700 g/mol). A study of the antioxidant properties of the oxidized and protonated forms of AG show that the obtained antioxidant activity (AOA) values are generally characteristic of polyuronic acids. Therefore, the TEMPO oxidation of AG and other neutral polysaccharides can be considered a promising approach for obtaining compounds with the necessary controlled characteristics. [ABSTRACT FROM AUTHOR]

Salivary complement inhibitors occur in many of the blood feeding arthropod species responsible for transmission of pathogens. During feeding, these inhibitors prevent the production of proinflammatory anaphylatoxins, which may interfere with feeding, and limit formation of the membrane attack complex which could damage arthropod gut tissues. Salivary inhibitors are, in many cases, novel proteins which may be pharmaceutically useful or display unusual mechanisms that could be exploited pharmaceutically. Albicin is a potent inhibitor of the alternative pathway of complement from the saliva of the malaria transmitting mosquito, Anopheles albimanus. Here we describe the cryo-EM structure of albicin bound to C3bBb, the alternative C3 convertase, a proteolytic complex that is responsible for cleavage of C3 and amplification of the complement response. Albicin is shown to induce dimerization of C3bBb, in a manner similar to the bacterial inhibitor SCIN, to form an inactive complex unable to bind the substrate C3. Size exclusion chromatography and structures determined after 30 minutes of incubation of C3b, factor B (FB), factor D (FD) and albicin indicate that FBb dissociates from the inhibited dimeric complex leaving a C3b-albicin dimeric complex which apparently decays more slowly. Structural analysis using cryo-EM reveals that albicin, an inhibitor of the alternative pathway of complement from the saliva of a mosquito, binds the C3bBb complex through contacts with both chains of C3b as well as the protease factor B. [ABSTRACT FROM AUTHOR]

Owing to the increasing interest in sustainability and bio-based materials, softwood kraft lignin (SKL) was acetone-fractionated to reduce its heterogeneity and then demethylated to substitute phenol in lignin–phenol–formaldehyde (LPF) resins to be used as bio-based wood adhesives. This study investigated the effect of the demethylation of acetone-soluble SKL (AS-SKL) on the adhesion of LPF resins, where phenol was partially replaced with acetone-soluble demethylated kraft lignin (AS-DKL). Characterization of SKL, AS-KL, and AS-DKL using gel permeation chromatography (GPC), FTIR, and 31P NMR spectroscopy showed that the demethylation was successfully performed; the molecular weight (MW) and the number of methoxy groups decreased, and the number of –OH groups increased. The MW, chemical reactions, and curing behavior of LPF resins synthesized with different AS-DKL levels (10, 20, 30, and 50 wt%) were also characterized. With the increase in AS-DKL content, the viscosity and MW of the resin increased, whereas the gelation time decreased. LPF resins with 10% AS-DKL showed the highest tensile shear strength and lowest peak curing temperature. These results suggest that 10% is an optimal AS-DKL level in LPF resins for plywood bonding and that demethylation is an effective way of utilizing SKL. [ABSTRACT FROM AUTHOR]

In order to explore more sustainable epoxy resins, a series of novel bio‐based epoxy resins with long silicone‐chain are synthesized from honokiol. First, honokiol epoxy (HOEP) is synthesized from honokiol. Then, the hydrogen‐containing siloxane (HS) is copolymerized with honokiol epoxy, and the bio‐based epoxy resins with long silicone‐chain are prepared through the hydrosilylation reaction. Before curing with methyl hexahydrophthalic anhydride (MHHPA), the structure of silicone honokiol epoxy (SIHOEP) is confirmed by Fourier‐transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (1H NMR). The molecular weight of SIHOEP is analyzed by gel permeation chromatography (GPC). The results show that the toughness of SIHOEP‐MHHPA is enhanced after curing, the maximum elongation at break reached 45.75%, and the glass transition temperature (Tg) is up to 92.9 °C. Long silicone‐chain segment can enhance the toughness of bio‐based epoxy. By adjusting the hydrogen content of long‐chain hydrogen‐containing siloxane and the reaction ratio, the overall performance of bio‐based epoxy silicone resins can be effectively controlled, which provides a valuable guide for the design of bio‐based epoxy materials with excellent mechanical properties. Meanwhile, the curing kinetics of bio‐based silicone/epoxy hybrid resins with methyl hexahydrophthalic anhydride (MHHPA) as curing agent is studied. [ABSTRACT FROM AUTHOR]

In this work, we have designed unique poly(lactic acid- co -glycolic acid)- b -poly(ethylene oxide)- b -poly(propylene oxide)- b -poly(ethylene oxide)- b -poly(lactic acid- co -glycolic acid) pentablock copolymers using Pluronic F68 and F108 triblock copolymers as macroinitiators. The poly(lactic acid- co -glycolic acid) (PLGA) blocks were attached as glycolide and lactide monomers at the both ends of each F68 and F108 triblock copolymer. The molecular weights and the block fractions were confirmed by gel permeation chromatography (GPC) and proton nuclear magnetic resonance (1H NMR) for the four kinds of pentablock copolymers. Using these pentablock copolymers as templates, we synthesized mesoporous ethane-silicas as well as silicas by the evaporation-induced self-assembly (EISA) method. 1,2-bis(triethoxysily)ethane (BTEE) were used as an organosilica precursor. The mesoporous ethane-silica samples were characterized using synchrotron small angle X-ray scattering (SAXS), nitrogen sorption experiments, transmission electron microscopy (TEM), and solid-state 29Si CP-MAS NMR. Based on the experimental results, it was confirmed that the porosity and pore diameter can be varied with the PLGA weight fraction of the pentablock copolymer. It is due to the PLGA block in polymer forming the hydrophobic domain in micelles, which leads to the formation of increased pore size over 20 nm without any additive pore expander. In addition, it seems that as the organosilica precursor increases, the association number of block copolymers forming one micelle decreases, resulting in a decrease in pore size. In summary, the polymer template plays a vital part in tuning the structure of the mesoporous ethane-silica samples. Thus, the development of synthetic method of mesoporous organosilica materials using polymer templates with different topology is still challenging and can endow the unique structure and property for mesoporous organosilica for future applications. [ABSTRACT FROM AUTHOR]

The cyclic oligosaccharide β‐cyclodextrin (β‐CDx) is investigated regarding its ability on principle to reduce the debranching activity of pullulanase (PUL) or even terminate the enzymatic hydrolysis process of starch polymers completely. For this purpose, dissolved β‐CDx (aqueous solution) is mixed with the diluted PUL compound (solution) and conditioned (stirred at 40 °C for various durations [0, 20, 40, and 60 min; at 26.75 nmol β‐CDx U−1] and at various β‐CDx dosages [5.35, 13.375, 26.75, and 53.5 nmol β‐CDx U−1; reaction time 60 min]). The PUL‐CDx‐mixtures are subsequently added to a 2.5% w/w starch solution (related to the initial specific debranching activity; 1593.6 NPUN g−1/557.8 U g−1) and gently stirred for 20 min at 40 °C before final thermal inactivation. The obtained samples are diluted and characterized molecularly, i.e., by means of size exclusion chromatography (SEC). An increasing β‐CDx dosage reduces the degree of molecular degradation systematically reflecting a successively reduced enzyme activity. However, the reaction time (PUL‐CDx‐mixture) has no impact on the enzyme's activity since the starch degradation is marginally and the SEC‐chromatograms similar to the one of the initial starch. Restrictions of the enzyme inhibiting effect of β‐CDx are found terminating the hydrolysis process in a starch suspension. [ABSTRACT FROM AUTHOR]

A tetra(ethylene glycol)‐based 1,3,4,5‐tetrasubstituted poly(1,2,3‐triazolium) is synthesized in two steps including: i) the catalyst‐free polyaddition of a diazide and an activated internal dialkyne and ii) the N‐alkylation of the resulting 1,2,3‐triazole groups. In order to provide detailed structure/properties correlations different analogs are also synthesized. First, parent poly(1,2,3‐triazole)s are obtained via AA+BB polyaddition using copper(I)‐catalyzed alkyne‐azide cycloaddition or metal‐free thermal alkyne‐azide cycloaddition (TAAC). Poly(1,2,3‐triazole)s with higher molar masses are obtained in higher yields by TAAC polyaddition. A 1,3,4‐trisubstituted poly(1,2,3‐triazolium) structural analog obtained by TAAC polyaddition using a terminal activated dialkyne and subsequent N‐alkylation of the 1,2,3‐triazole groups enables discussing the influence of the methyl group in the C‐4 or C‐5 position on thermal and ion conducting properties. Obtained polymers are characterized by 1H, 13C, and 19F NMR spectroscopy, differential scanning calorimetry, thermogravimetric analysis, size exclusion chromatography, and broadband dielectric spectroscopy. The targeted 1,3,4,5‐tetrasubstituted poly(1,2,3‐triazolium) exhibits a glass transition temperature of −23 °C and a direct current ionic conductivity of 2.0 × 10−6 S cm−1 at 30 °C under anhydrous conditions. The developed strategy offers opportunities to further tune the electron delocalization of the 1,2,3‐triazolium cation and the properties of poly(1,2,3‐triazolium)s using this additional substituent as structural handle. [ABSTRACT FROM AUTHOR]

Biodegradable polymers play a crucial role in the development of materials for biomedical applications. This study investigates the enzymatic biodegradation, bioactivity, and cytotoxicity of poly(butylene succinate‐dilinoleic succinate) (PBS‐DLS) copolymers modified with poly(ethylene glycol) (PEG). Two copolymer variations with different segmental compositions (70 wt.% and 60 wt.% of hard segments) are synthesized. After modifying the copolymers with PEG, the presence of a lipase catalyst accelerated degradation after 20 days, evidenced by reduced residual content. Gel permeation chromatography analysis showed up to 40% decrease in molecular weight, while gravimetric analysis indicated a mass loss of up to 10%. Morphological examination revealed that the enzymatic breakdown, facilitated by hydrolase activity (boosted by the presence of PEG), resulted in surface erosion, holes, and changes in spherulitic morphology. Bioactivity studies demonstrated the formation of biomimetic calcium/phosphate (Ca/P) crystals. Copolymers with higher crystallinity (70 wt.% hard segments) favored tricalcium phosphate‐like crystal formation, while those with lower crystallinity (60 wt.% hard segments) are more susceptible to hydroxyapatite precipitation. In vitro cytotoxicity tests exhibited excellent cell viability and attachment for all copolymers. The ability to control degradation through PEG modification, along with their bioactivity and cell compatibility, positions them as promising candidates for diverse biomedical applications. [ABSTRACT FROM AUTHOR]

Pour Point Depressant is introduced to crude oil at ppm level to overcome transportation problem of crude oil because of its complex chemical structure. Synthesized PPDs improve flow property, viscosity and also improve its numerous parameters to improve performance of crude oil. Low molecular weight and high molecular weight, copolymer having better PPD types. In present work, synthesized Terpolymer, from natural source, was formed from the reaction with Helianthus annuus oil and ester of Erucic Acid with various fatty alcohol. It was evaluated for its properties on Indian waxy crude oils, i.e., From Limbodra well. Structure and molecular weight of synthesized polymer was confirmed by Spectral data and Gel permeation chromatography (GPC). Also its effect on crude oil was evaluated by Rheological studies, SARA Analysis, Pour point depressant effect. Cross–polarizing microscopic studies were performed to study changes in morphology of wax crystals in crude oil with and without additive. A zero friction advanced Rheometer AR-500 was used to determine the viscosity by applying Bingham plastic-flow model. [ABSTRACT FROM AUTHOR]

Size exclusion chromatography with total organic carbon detection (HPSEC-TOC) is a widely employed technique for characterizing aquatic natural organic matter (NOM) into high, medium, and low molecular weight fractions. This study validates the suitability of HPSEC-TOC for a simplified yet efficient routine analysis of freshwater and its application within drinking water treatment plants. The investigation highlights key procedural considerations for optimal results and shows the importance of sample preservation by refrigeration with a maximum storage duration of two weeks. Prior to analysis, the removal of inorganic carbon is essential, which is achieved without altering the NOM composition through sample acidification to pH 6 and subsequent N2-purging. The chromatographic separation employs a preparative TSK HW-50S column to achieve a limit of detection of 19.0 µgC dm−3 with an injection volume of 1350 mm−3. The method demonstrates linearity up to 10,000 µgC dm−3. Precision, trueness and recovery assessments are conducted using certified reference materials, model compounds, and real water samples. The relative measurement uncertainty in routine analysis ranges from 3.22% to 5.17%, while the measurement uncertainty on the bias is 8.73%. Overall, the HPSEC-TOC represents a reliable tool for NOM fractions analysis in both treated and untreated ground and surface water. [ABSTRACT FROM AUTHOR]

Age-related macular degeneration (AMD) is an age-related disorder that is a global public health problem. The non-enzymatic Maillard reaction results in the formation of advanced glycation end products (AGEs). Accumulation of AGEs in drusen plays a key role in AMD. AGE-reducing drugs may contribute to the prevention and treatment of AGE-related disease. Fructosamine oxidase (FAOD) acts on fructosyl lysine and fructosyl valine. Based upon the published results of fructosamine 3-kinase (FN3K) and FAOD obtained in cataract and presbyopia, we studied ex vivo FAOD treatment as a non-invasive AMD therapy. On glycolaldehyde-treated porcine retinas, FAOD significantly reduced AGE autofluorescence (p = 0.001). FAOD treatment results in a breakdown of AGEs, as evidenced using UV fluorescence, near-infrared microspectroscopy on stained tissue sections of human retina, and gel permeation chromatography. Drusen are accumulations of AGEs that build up between Bruch's membrane and the retinal pigment epithelium. On microscopy slides of human retina affected by AMD, a significant reduction in drusen surface to 45 ± 21% was observed following FAOD treatment. Enzymatic digestion followed by mass spectrometry of fructose- and glucose-based AGEs (produced in vitro) revealed a broader spectrum of substrates for FAOD, as compared to FN3K, including the following: fructosyllysine, carboxymethyllysine, carboxyethyllysine, and imidazolone. In contrast to FN3K digestion, agmatine (4-aminobutyl-guanidine) was formed following FAOD treatment in vitro. The present study highlights the therapeutic potential of FAOD in AMD by repairing glycation-induced damage. [ABSTRACT FROM AUTHOR]

Human cystatin C (hCC), a small secretory protein, has gained attention beyond its classical role as a cysteine protease inhibitor owing to its potential involvement in neurodegenerative disorders. This study investigates the interaction between copper(II) ions [Cu(II)] and hCC, specifically targeting histidine residues known to participate in metal binding. Through various analytical techniques, including mutagenesis, circular dichroism, fluorescence assays, gel filtration chromatography, and electron microscopy, we evaluated the impact of Cu(II) ions on the structure and oligomerization of hCC. The results show that Cu(II) does not influence the secondary and tertiary structure of the studied hCC variants but affects their stability. To explore the Cu(II)‐binding site, nuclear magnetic resonance (NMR) and X‐ray studies were conducted. NMR experiments revealed notable changes in signal intensities and linewidths within the region 86His‐Asp‐Gln‐Pro‐His90, suggesting its involvement in Cu(II) coordination. Both histidine residues from this fragment were found to serve as a primary anchor of Cu(II) in solution, depending on the structural context and the presence of other Cu(II)‐binding agents. The presence of Cu(II) led to significant destabilization and altered thermal stability of the wild‐type and H90A variant, confirming differentiation between His residues in Cu(II) binding. In conclusion, this study provides valuable insights into the interaction between Cu(II) and hCC, elucidating the impact of copper ions on protein stability and identifying potential Cu(II)‐binding residues. Understanding these interactions enhances our knowledge of the role of copper in neurodegenerative disorders and may facilitate the development of therapeutic strategies targeting copper‐mediated processes in protein aggregation and associated pathologies. [ABSTRACT FROM AUTHOR]

Interferon induced transmembrane proteins (IFITMs) play a dual role in the restriction of RNA viruses and in cancer progression, yet the mechanism of their action remains unknown. Currently, there is no data about the basic biochemical features or biophysical properties of the IFITM1 protein. In this work, we report on description and biochemical characterization of three conformational variants/oligomeric species of recombinant IFITM1 protein derived from an Escherichia coli expression system. The protein was extracted from the membrane fraction, affinity purified, and separated by size exclusion chromatography where two distinct oligomeric species were observed in addition to the expected monomer. These species remained stable upon re-chromatography and were designated as "dimer" and "oligomer" according to their estimated molecular weight. The dimer was found to be less stable compared to the oligomer using circular dichroism thermal denaturation and incubation with a reducing agent. A two-site ELISA and HDX mass spectrometry suggested the existence of structural motif within the N-terminal part of IFITM1 which might be significant in oligomer formation. Together, these data show the unusual propensity of recombinant IFITM1 to naturally assemble into very stable oligomeric species whose study might shed light on IFITM1 anti-viral and pro-oncogenic functions in cells. [ABSTRACT FROM AUTHOR]

Calotropis procera produces a latex used in traditional medicine because of its components which are found to be biologically active. The latex of C. procera has many benefits such as pain reduction, antimicrobial attitude and other precious attributes. Latex lysozyme (LL) is a particular protein contained in C. procera plant having a promising antibacterial property. The process applied for extraction implicated ammonium sulfate precipitation, water extraction, ion exchange and gel filtration column chromatography evidencing 14.4 kDa for LL as a molecular mass. LL after purification showed 397.18 U mg−1 as specific activity (10.30 purification fold), and with 37.9% as a yield. In addition, the chemical and physical analyses showed that LL had its best realization when the pH was 5.5 at 50 °C. Moreover when metal ions such as Ca2+ and Mg2+ were incorporated the relative activity of the enzyme resulted ampliflied. When a purification was conducted with CM-Cellulose and Sephadex G-100 chromatography, LL revealed an antibacterial property versus both Escherichia coli (MICs 14 µg ml−1) and Bacillus cereus (MICs 13 µg ml−1). HR-TEM analysis displayed an antimicrobial potential of LL after its purification; that analysis showed the deterioration of the cell wall (external membrane of the cell) of both E. coli and B. cereus. Therefore, the LL obtained from C. procera maintains ability as an antibacterial enzyme applicable in various domains such as biotechnological and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

L-glutamic acid (LA) is a bio-based, non-toxic, environmentally friendly material derived from biomass. The present study reports the application of Passerini three-component polymerization (P-3CP) for the straightforward preparation of LA-based light-responsive polyesters (PLTDs) under mild conditions. PLTDs with molar masses up to 8500 g/mol and high yields exceeding 90% are obtained. The chemical structures and light-responsive self-immolative behavior of PLTDs are comprehensively characterized by employing ultraviolet-visible (UV-Vis) spectroscopy, size exclusion chromatography (SEC), nuclear magnetic resonance (NMR) spectroscopy, and liquid chromatography mass spectrometry (LC-MS). Meanwhile, monodisperse PLTD-based doxorubicin-loaded nanoparticles (PLTD-DOX-NP) (size=193 nm, PDI=0.018) are formulated by nanoprecipitation method. Upon light-induced depolymerization, the PLTD-DOX-NP undergoes rapid decomposition, resulting in a burst release of 80% cargo within 13 s. Furthermore, according to biological toxicity tests, the PLTD-NP possesses adequate biosafety, both before and after irradiation. Overall, the incorporation of P-3CP with biorenewable LA-based monomer adheres to the principles of green chemistry, significantly simplifying the synthetic pathway of light-responsive polymers. [ABSTRACT FROM AUTHOR]

This document summarizes a study on the synthesis and characterization of various compounds, including trifluoromethyl arenes. The study focuses on the hydrolysis of the trifluoromethyl group to carboxylic acid, which is challenging but important for pharmaceutical applications. The authors propose a method using a combined base system that efficiently mediates this transformation. The document provides experimental procedures, spectral data, and acknowledges the use of an EPR apparatus from Tohoku University. The data obtained for the compounds synthesized in the study match those reported in the literature. [Extracted from the article]

The direct utilization of H2S in polymerization is rarely reported. Here step polymerization of H2S and diacrylates using commercially available organic bases as the catalysts is reported. Poly(thioether‐ester)s are successfully synthesized in an atom‐economical way, as confirmed by 1H NMR spectra, and the molecular weights of these poly(thioether‐ester)s can be up to 64.7 kDa as determined by the gel permeation chromatography, which also shows the polymerization of H2S with diacrylates is stepwise manner. The calculation results show that H2S is first deprotonated by organic base, and the generated HS‐ attacks the double bond of diacrylates through anionic Michael addition, to form the intermediate with double bond and ─SH ends or two ─SH ends (slight excess H2S used). The continuous self‐Michael addition of the polymer species with double bond and ─SH ends is the main manner for chain growth. The resultant polymers exhibit tensile strength and elongation at breaks of as high as 21.6 MPa and 1031%, respectively and can be chemically recycled. This work provides a facile and atom‐economical method to produce sulfur‐containing polymers by directly using commercially available H2S. [ABSTRACT FROM AUTHOR]

The synthesis of amphiphilic diblock and statistical (random) copolymers of poly(dimethylamino ethyl methacrylate) and poly((2-(diisopropylamino) ethyl methacrylate) using the reversible addition–fragmentation chain transfer polymerization technique (RAFT polymerization) is reported. The precursor copolymers were chemically modified to create derivative copolymers of polyelectrolyte and polyampholyte nature with novel solution properties. Moreover, their molecular and physicochemical characteristics, as well as their self-assembly in aqueous media as a function of molecular architecture and composition, are investigated by using size exclusion chromatography, spectroscopic characterization techniques and light scattering techniques. Furthermore, the behavior and properties of the obtained micelles and aggregates were studied, depending on the pH, temperature and ionic strength of the aqueous solutions. The response of the systems to changes in these parameters shows interesting behavior and new properties that are useful for their utilization as nanocarriers of pharmaceutical compounds. [ABSTRACT FROM AUTHOR]

Undoubtedly, with the increasing awareness of the scientific community and the public, current trends are directing research to implement effective and combined yet nature friendly methodologies. Due to advantages such as adaptability and versatility, the combination of electrospinning and light is increasingly intriguing. This study proposes a new strategy for producing amphiphilic fibers from graft copolymer of polypropylene (PP) and poly (acrylic acid) (FPP-g-PAA). The first step includes the synthesis of copolymer comprising PP main chain possessing poly (tertiary butyl acrylate) pendant groups via photo-induced metal-free atom transfer radical polymerization (PIMF-ATRP) of tertiary butyl acrylate (t-BA) in the presence of perylene and chlorinated polypropylene (PP-Cl) as a macro photo-initiator (PP-g-PtBA). Then, FPP-g-PAA is prepared by acidolysis of t-BA units to acrylic acid moieties. In the second step, the PP-g-PAA is successful electrospun to fabricate the ultimate amphiphilic fibers. The chemical steps are monitored and confirmed by Fourier-transform infrared (FT-IR) and proton magnetic resonance (1H-NMR) spectroscopies, and gel permeation chromatography (GPC). Following the structural characterization, morphological and wetting properties are systematically determined with scanning electron microscopy (SEM) and water contact angle (WCA) measurement by depending on surface characteristics of the samples. Thermal behaviour of precursors and synthesized electrospun fibers has also been evaluated and compared by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The SEM images display that the achieved fibers were smooth and circular with the average diameters ranging from 3.3 μm up to 3.9 μm. After WCA measurements, it was elucidated that the hydrophobic nature of electrospun PP-g-PtBA was transformed into amphiphilic structure by hydrolysis of PtBA pendant groups. The reported approach is very encouraging and expected to trigger further development for scientists preparing various types of amphiphilic polyolefin fiber based materials. [ABSTRACT FROM AUTHOR]

Coronavirus disease 2019 (COVID-19) is characterized by a broad spectrum of clinical manifestations with the potential to progress to multiple organ dysfunction in severe cases. Extracellular vesicles (EVs) carry a range of biological cargoes, which may be used as biomarkers of disease state. An exploratory secondary analysis of the SARITA-2 and SARITA-1 datasets (randomized clinical trials on patients with mild and moderate/severe COVID-19) was performed. Serum-derived EVs were used for proteomic analysis to identify enriched biological processes and key proteins, thus providing insights into differences in disease severity. Serum-derived EVs were separated from patients with COVID-19 by size exclusion chromatography and nanoparticle tracking analysis was used to determine particle concentration and diameter. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was performed to identify and quantify protein signatures. Bioinformatics and multivariate statistical analysis were applied to distinguish candidate proteins associated with disease severity (mild versus moderate/severe COVID-19). No differences were observed in terms of the concentration and diameter of enriched EVs between mild (n = 14) and moderate/severe (n = 30) COVID-19. A total of 414 proteins were found to be present in EVs, of which 360 were shared while 48 were uniquely present in severe/moderate compared to mild COVID-19. The main biological signatures in moderate/severe COVID-19 were associated with platelet degranulation, exocytosis, complement activation, immune effector activation, and humoral immune response. Von Willebrand factor, serum amyloid A-2 protein, histone H4 and H2A type 2-C, and fibrinogen β-chain were the most differentially expressed proteins between severity groups. Exploratory proteomic analysis of serum-derived EVs from patients with COVID-19 detected key proteins related to immune response and activation of coagulation and complement pathways, which are associated with disease severity. Our data suggest that EV proteins may be relevant biomarkers of disease state and prognosis. [ABSTRACT FROM AUTHOR]

The properties of nanomedicines will influence how they can deliver drugs to patients reproducibly and effectively. For conventional pharmaceutical products, Chemistry, Manufacturing and Control (CMC) documents require monitoring stability and storage conditions. For nanomedicines, studying these important considerations is hindered by a lack of appropriate methods. In this paper, we show how combining radiolabelling with size exclusion chromatography, using a method called SERP (for Size Exclusion of Radioactive Polymers), can inform on the in vitro degradation of polymer nanoparticles. Using nanoparticles composed of biodegradable poly(lactic acid) (PLA) and poly(lactic- co -glycolic acid) (PLGA), we show that SERP is more sensitive than dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA) to detect degradation. We also demonstrate that the properties of the polymer composition and the nature of the aqueous buffer affect nanoparticle degradation. Importantly, we show that minute changes in stability that cannot be detected by DLS and NTA impact the pharmacokinetic of nanoparticles injected in vivo. We believe that SERP might prove a valuable method to document and understand the pharmaceutical quality of polymer nanoparticles. [Display omitted] [ABSTRACT FROM AUTHOR]

Ultrasound assisted hot water extraction (UAHWE) was applied to extraction of polysaccharides from Taraxacum mongolicum with hot water as extract solvent. Experimental factors in UAHWE process were optimized by response surface methodology. The optimal extraction parameters to achieve the highest Taraxacum mongolicum polysaccharides (TMPs) yield (12.08 ± 0.14)% by UAHWE were obtained under the ultrasound power of 200 W, extraction temperature of 62°C, solid‐to‐liquid ratio of 1:20 g/mL, and extraction time of 40 min, and then the crude TMPs were further purified by DEAE‐52 and Sephadex G‐100 chromatography to obtain a homogenous polysaccharide fraction (TMPs‐1‐SG). Subsequently, the structure of TMPs‐1‐SG was characterized by UV‐vis, Fourier transform infrared spectroscopy (FT–IR), high performance gel permeation chromatography (HPGPC), high performance liquid chromatography (HPLC), scanning electron microscope (SEM), transmission electron microscopy (TEM), and Congo red test. The results display that TMPs‐1‐SG with an average molecular weight of 5.49 × 104 Da was comprised of mannose (Man), galactose (Gal), xylose (Xyl), and arabinose (Ara) with a molar ratio of 39.85:52.61:27.14:6.30. Moreover, TMPs‐1‐SG did not contain a triple helix structure. Furthermore, TMPs‐1‐SG and TEM presented a sheet‐like, rod‐shaped, and irregular structure. Finally, the antioxidant activity of TMPs‐1‐SG was evaluated by in vitro experiment. The IC50 values of scavenging DPPH and OH radicals for TMPs‐1‐SG achieved 0.71 mg/mL and 0.75 mg/mL, respectively. The findings can provide an effective method for extracting polysaccharides from natural resources. [ABSTRACT FROM AUTHOR]

Given the multitude of extracellular enzymes at their disposal, many of which are designed to degrade nature's polymers (lignin, cutin, cellulose, etc.), fungi are adept at targeting synthetic polyesters with similar chemical composition. Microbial-influenced deterioration of xenobiotic polymeric surfaces is an area of interest for material scientists as these are important for the conservation of the underlying structural materials. Here, we describe the isolation and characterization of the Papiliotrema laurentii 5307AH (P. laurentii) cutinase, Plcut1. P. laurentii is basidiomycete yeast with the ability to disperse Impranil-DLN (Impranil), a colloidal polyester polyurethane, in agar plates. To test whether the fungal factor involved in this clearing was a secreted enzyme, we screened the ability of P. laurentii culture supernatants to disperse Impranil. Using size exclusion chromatography (SEC), we isolated fractions that contained Impranil-clearing activity. These fractions harbored a single ~22 kD band, which was excised and subjected to peptide sequencing. Homology searches using the peptide sequences identified, revealed that the protein Papla1 543643 (Plcut1) displays similarities to serine esterase and cutinase family of proteins. Biochemical assays using recombinant Plcut1 confirmed that this enzyme has the capability to hydrolyze Impranil, soluble esterase substrates, and apple cutin. Finally, we confirmed the presence of the Plcut1 in culture supernatants using a custom antibody that specifically recognizes this protein. The work shown here supports a major role for the Plcut1 in the fungal degradation of natural polyesters and xenobiotic polymer surfaces. [ABSTRACT FROM AUTHOR]

To reduce the cost of silica-based materials, an agricultural waste, rice husk (RH), was transformed into higher valuable products such as MCM-41 and organo-functionalized MCM-41 in the frame of circular economy. RH is the biomass waste containing the highest amount of silica (214 g kg−1). Direct calcination of RH led to silica with low surface area (10 m2 g−1), which could not be transformed into MCM-41. After optimization, silica of 310 m2 g−1 was produced by washing RH with HCl 0.1 mol L−1 at 25 °C and calcination at 600 °C. Such silica was successfully transformed in one-step synthesis at 115 °C for 24 h into highly ordered MCM-41 (800 m2 g−1) and organo-functionalized MCM-41 (510–720 m2 g−1) including aminopropyl and amide derivatives of amino acids (leucine, serine and tyrosine). The corresponding organo-triethoxysilanes alone or in mixture were directly added in the synthesis with silica from RH, octadecyltrimethylammonium and NaOH solution. Surfactant removal was successfully performed with EtOH/NH4NO3 solution at 60 °C. The mesopore diameter of the materials were homogeneous and varied from 3.8 to 4.2 nm depending on the organic functions. Thanks to the use of the concept of pseudomorphic transformation, the particle size of the materials ranged from 1 to 100 μm. As proof of concept, the 50–100 μm fraction (30% of the volume) was successfully used to fill columns to run size exclusion chromatography for protein separation. The largest protein, bovine serum albumine (BSA) was excluded from all materials as its kinetic diameter (d = 7.2 nm) was larger than the mesopore diameter. The smallest proteins: carbonic anhydrase (d = 4.2 nm), myoglobin (d = 3.8 nm) and lysozyme (d = 3.4 nm) were retained by the materials. Their retention factor increased as the kinetic diameter decreased, as the mesopore diameter decreased and as the hydrophobicity of the materials increased. The best separation of proteins was obtained with MCM-41 functionalized with both leucine and serine amide derivatives. [ABSTRACT FROM AUTHOR]

The development of donor–acceptor conjugated polymers is a challenge due to the involvement of costly transition-metal catalysts and hazardous reagents during the synthesis of such materials, which may potentially cause serious environmental problems. Aldol polycondensation is a promising, metal-free polymerization method to synthesize such donor–acceptor conjugated polymers. Herein, we report the synthesis of three new symmetrical diformyl functionalized thiophene-capped carbazole, fluorene and indolocarbazole moieties. The polymers, ACRBI, AFRBI and AICRBI, were synthesized by aldol condensation reaction between the diformyl compounds and bis(indolinone). Photophysical, electrochemical, and thermogravimetric analyses, gel permeation chromatography, DFT calculations and SCLC hole mobility measurements were performed for these polymers. The photophysical and electrochemical studies of these polymers revealed high visible light absorptivity with a HOMO energy level close to −5.5 eV and a low-lying LUMO energy level close to −3.35 eV. The SCLC hole mobilities of polymers ACRBI, AFRBI and AICRBI were determined to be 4.9 × 10−3, 6.7 × 10−2, and 1.7 × 10−3 cm2 V−1 S−1, respectively. [ABSTRACT FROM AUTHOR]

The red abalone (Haliotis rufescens) represents North America's most important aquaculture species. Its hepatopancreas is rich in cellulases and other polysaccharide-degrading enzymes, which provide it the remarkable ability to digest cellulose-rich macroalgae; nevertheless, its cellulolytic systems are poorly explored. This manuscript describes some functional and structural properties of an endogenous trimeric glycosylated endoglucanase from H. rufescens. The purified enzyme showed a molecular mass of 23.4 kDa determined by MALDI-TOF mass spectrometry, which behaved as a homotrimer in gel filtration chromatography and zymograms. According to the periodic acid-Schiff reagent staining, detecting sugar moieties in SDS-PAGE gel confirmed that abalone cellulase is a glycoprotein. Hydrolysis of cello-oligosaccharides and p-nitrophenyl-β-D-glucopyranosides confirmed its endo/exoactivity. A maximum enzyme activity toward 0.5% (w/v) carboxymethylcellulose of 53.9 ± 1.0 U/mg was achieved at 45°C and pH 6.0. We elucidated the abalone cellulase primary structure using proteases and mass spectrometry methods. Based on these results and using a bioinformatic approach, we identified the gene encoding this enzyme and deduced its full-length amino acid sequence; the mature protein comprised 177 residues with a calculated molecular mass of 19.1 kDa and, according to sequence similarity, it was classified into the glycosyl-hydrolase family 45 subfamily B. An AlphaFold theoretical model and docking simulations with cellopentaose confirmed that abalone cellulase is a β-sheet rich protein, as also observed by circular dichroism experiments, with conserved catalytic residues: Asp26, Asn109, and Asp134. Interestingly, the AlphaFold-Multimer analysis indicated a trimeric assembly for abalone cellulase, which supported our experimental findings. The discovery and characterization of these enzymes may contribute to developing efficient cellulose bioconversion processes for biofuels and sustainable bioproducts. [ABSTRACT FROM AUTHOR]

Exosomes‐like nanoparticles (ELNs) (exosomes or extracellular vesicles) are vesicle‐like bodies secreted by cells. Plant ELNs (PENs) are membrane vesicles secreted by plant cells, with a lipid bilayer as the basic skeleton, enclosing various active substances such as proteins and nucleic acids, which have many physiological and pathological functions. Recent studies have found that the PENs are widespread within different plant species and their biological functions are increasingly recognized. The effective separation method is also necessary for its function and application. Ultracentrifugation, sucrose density gradient ultracentrifugation, ultrafiltration, polymer‐based precipitation methods, etc., are commonly used methods for plant exosome‐like nanoparticle extraction. In recent years, emerging methods such as size exclusion chromatography, immunoaffinity capture‐based technique, and microfluidic technology have shown advancements compared to traditional methods. The standardized separation process for PENs continues to evolve. In this review, we summarized the recent progress in the biogenesis, components, separation methods, and some functions of PENs. When the research on the separation method of PENs and their unique biological structure is further studied. A brand‐new idea for the efficient separation and utilization of PENs can be provided in the future, which has a very broad prospect. [ABSTRACT FROM AUTHOR]

Polymers with cyclic topology have no terminal structure and, therefore, exhibit various unique physical and functional properties compared to those of linear analogs. In this paper, we report an innovative methodology for the synthesis of cyclic polymers via ring-expansion RAFT (RE-RAFT) polymerization of vinyl monomers using a cyclic trithiocarbonate derivative (CTTC) as a RAFT agent. RE-RAFT of tert-butyl acrylate (TBA) was performed to yield a mixture of polymers exhibiting a bimodal size exclusion chromatography (SEC) trace. Both the peak top molecular weights shifted to higher-molecular-weight regions as the monomer conversion increased. The structure of the resulting polymer mixture was examined by 1H NMR and MALDI-TOF-MS. Detailed studies indicated that the obtained polymer of higher molecular weight was one of the large-sized cyclic polymers generated by the fusion of smaller-sized cyclic polymers during the RE-RAFT polymerization process. This approach opens the door to the simple synthesis of well-controlled cyclic polymers with complex structures, such as alternating and multi-block repeat unit sequences. [ABSTRACT FROM AUTHOR]

AHP-3a, a triple-helix acidic polysaccharide isolated from Alpinia officinarum Hance, was evaluated for its anticancer and antioxidant activities. The physicochemical properties and structure of AHP-3a were investigated through gel permeation chromatography, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. The weight-average molecular weight of AHP-3a was 484 kDa, with the molar percentages of GalA, Gal, Ara, Xyl, Rha, Glc, GlcA, and Fuc being 35.4%, 21.4%, 16.9%, 11.8%, 8.9%, 3.1%, 2.0%, and 0.5%, respectively. Based on the results of the monosaccharide composition analysis, methylation analysis, and NMR spectroscopy, the main chain of AHP-3a was presumed to consist of (1→4)-α-D-GalpA and (1→2)-α-L-Rhap residues, which is a pectic polysaccharide with homogalacturonan (HG) and rhamnogalacturonan-I (RG-I) structural domains containing side chains. In addition, the results of the antioxidant activity assay revealed that the ability of AHP-3a to scavenge DPPH, ABTS, and OH free radicals increased with an increase in its concentration. Moreover, according to the results from the EdU, wound healing, and Transwell assays, AHP-3a can control the proliferation, migration, and invasion of HepG2 and Huh7 hepatocellular carcinoma cells without causing any damage to healthy cells. Thus, AHP-3a may be a natural antioxidant and anticancer component. [ABSTRACT FROM AUTHOR]

pH-sensitive amphiphilic diblock polyphosphoesters containing lactic acid units were synthesized by multistep one-pot polycondensation reactions. They comprise acid-labile P(O)-O-C and C(O)-O-C bonds, the cleavage of which depends on the pH of the medium. The structure of these copolymers was characterized by 1H, 13C {H}, 31P NMR, and size exclusion chromatography (SEC). The newly synthesized polymers self-assembled into the micellar structure in an aqueous solution. The effects of the molecular weight of the copolymer and the length of the hydrophobic chain on micelle formation and stabilityand micelle size were studied via dynamic light scattering (DLS). Drug loading and encapsulation efficiency tests using doxorubicin revealed that hydrophobic drugs can be delivered by copolymers. It was established that the molecular weight of the copolymer, length of the hydrophobic chain and content of lactate units affects the size of the micelles, drug loading, and efficiency of encapsulation. A copolymer with 10.7% lactate content has drug loading (3.2 ± 0.3) and efficiency of encapsulation (57.4 ± 3.2), compared to the same copolymer with 41.8% lactate content (1.63%) and (45.8%), respectively. It was demonstrated that the poly[alkylpoly(ethylene glycol) phosphate-b-alkylpoly(ethylene glycol)lactate phosphate] DOX system has a pH-sensitive response capability in the result in which DOX was selectively accumulated into the tumor, where pH is acidic. The results obtained indicate that amphiphilic diblock polyphosphoesters have potential as drug carriers. [ABSTRACT FROM AUTHOR]

[Display omitted] The competitive interaction of oxyanions and humic nanoparticles (HNPs) with metal (hydr)oxide surfaces can be used to trace the ligand and charge distribution of adsorbed HNPs in relation to heterogeneity, fractionation, and conformational change. Batch adsorption experiments of HNPs on goethite were performed in the absence and presence of phosphate. The size of HNPs was measured with size exclusion chromatography. The Ligand and Charge Distribution (LCD) model framework was further developed to describe the simultaneous interaction of HNPs and phosphate with goethite. Preferential adsorption decreases the mean molar mass of adsorbed HNPs, independent of the phosphate presence, showing a linear dependency on the adsorbed HNPs fraction. Phosphate ion can be used as a probe to trace the distribution of functional groups and the variation in affinity of HNPs. The spatial distribution of adsorbed HNPs is driven by the potential gradients in the electrical double layer, which changes the conformation of the adsorbed HNPs. At the particle level, the adsorption of heterogeneous HNPs has an affinity distribution, which can be explained by the variation in molar mass (kDa) and density of the functional groups (mol kg−1) of the HNPs. The presented model can simultaneously describe the competitive adsorption of HNPs and phosphate in a consistent manner. [ABSTRACT FROM AUTHOR]

Glycidyl-based chain extenders are broadly used as processing aids to enhance the physical properties of polyesters, but glycidyl-containing compounds have severe toxicity concerns. Reported herein are glycidyl-free chain extenders produced via the grafting of 9-(oxiran-2-yl)nonyl methacrylate (EAT) and 8-(3-octyloxiran-2-yl)octyl methacrylate (EAI) on biodegradable poly(e-caprolactone) (PCL). EAI and EAT were grafted onto PCL via free radical grafting using melt extrusion to produce PCL-epoxy-grafted PCL-g-EAI and PCL-g-EAT. The obtained PCL-g-EAI and PCL-g-EAT were characterized by 1H nuclear magnetic resonance (NMR) spectroscopy, intrinsic viscosity measurements, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and size exclusion chromatography (SEC). Using reactive melt extrusion, PCL-g-EAI and PCL-g-EAT were tested as potential chain extenders for poly(lactic acid) (PLA). PCL-g-EAI showed comparable or better mechanical properties than those of the commercial chain extender Joncryl ADR. A cytotoxicity assay has been conducted on PLA samples with the new chain extender and showed the absence of cytotoxicity in all samples. The outcomes reported in this paper offer new opportunities for the development of safer chain extenders. [ABSTRACT FROM AUTHOR]

This paper presents studies on the influence of the chemical structure of (meth)acrylic monomers on the properties of powder coatings based on polyacrylate resins. For this purpose, a wide range of monomers were selected—2-hydroxyethyl methacrylate (HEMA), methyl methacrylate (MMA), n-butyl acrylate (nBA), tert-butyl acrylate (tBA), dodecyl acrylate (DA), ethyl acrylate (EA) and benzyl acrylate (BAZ)—for the synthesis of the polyacrylate resin. The average molecular mass and molecular mass distribution of the synthesized resins were measured by gel permeation chromatography (GPC). The glass transition temperature (Tg) and viscosity of polyacrylate resins were determined by using differential scanning calorimetry (DSC) and a Brookfield viscometer. These parameters were necessary to obtain information about storage stability and behavior during the application of powder clear coatings. Additionally, DSC was also used to checked the course of the low-temperature curing reaction between the hydroxyl group contained in the polyacrylate resin and the blocked polyisocyanate group derived from a commercial agent such as Vestanat B 1358/100. The properties of the cured powder clear coatings were tested, such as: roughness, gloss, adhesion to the steel surface, hardness, cupping, scratch resistance, impact resistance and water contact angle. The best powder clear coating based on the polyacrylate resin L_HEMA/6MMA/0.5nBA/0.5DA was characterized as having good scratch resistance (550 g) and adhesion to the steel surface, a high water contact angle (93.53 deg.) and excellent cupping (13.38 mm). Moreover, its crosslinking density (CD) and its thermal stability was checked by using dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA). [ABSTRACT FROM AUTHOR]

Phaseolus lunatus have proven to be a likely source of peptides with bioactivities that could be used to prevent and treat chronic degenerative diseases like arterial hypertension (AHT). Angiotensin-I converting enzyme (ACE-I) inhibition is essential for the AHT pathophysiology. In this work, the kinetic study of inhibition and inhibitory activity of ACE-I from peptide fractions partially purified from a protein hydrolysate from Phaseolus lunatus was performed. Hydrolysis was done by sequential enzymatic treatments with Pepsin-Pancreatin. The hydrolysates were ultrafiltered with 3 kDa and 5 kDa membranes, obtaining a fraction of 3–5 kDa which was later purified by gel filtration chromatography (GFC) and high-performance liquid chromatography (HPLC). The GFC fractions exhibited ACE-I inhibitory activities (ACE-I_I) up to 37.86% with an IC 50 of 6.34 μg/mL. From HPLC purification, ACE-I_I up to 26.23% were obtained with an IC 50 of 2.69 μg/mL. The kinetic parameters of the inhibition indicated that the peptides inhibit ACE-I through a competitive mechanism. The amino acids of the fractions evaluated presented Pro, Ala, Leu, and Ile, which can be part of the peptide fractions with ACE-I_I; with these results obtained these peptides could be used as functional foods related to the control and prevention of diseases related to AHT. [Display omitted] • Lima bean peptide fractions were partially purified by chromatographic methods. • Peptide fractions < 3 kDa from Phaseolus lunatus inhibit ACE-I competitively. • The presence of threonine, alanine, isoleucine and serine probably inhibits ACE-1. [ABSTRACT FROM AUTHOR]

A rapid increase in viscosity during the polymerization process impacts the polymerization rate. To address this issue, ethylbenzene is often introduced into the polymerization system in order to reduce viscosity. The thermal characteristics of styrene–ethylbenzene polymerization have been identified using differential scanning calorimetry. The rate of heat generation significantly decreases as the proportion of ethylbenzene increases. The polymerization product mixtures were analyzed using gel permeation chromatography. Polymerization at low viscosity yields a higher proportion of low molecular mass polymers and a more uniform distribution of product chain lengths compared to polymerization at high viscosities. The glass transition temperature and the activation energy for viscous flow of the products were also determined. The apparent kinetics of styrene polymerization may be described using the "autocatalytic + Nth-order" model. Two stages of monomer conversion are apparent: polymerization reactions initiated by AIBN and thermally induced polymerization. Valuable insights into the polymerization process which can contribute to the optimization of industrial polymerization reactions have been obtained. [ABSTRACT FROM AUTHOR]