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Funding Information: The financial support of the Austrian Federal Ministry of Digital and Economic Affairs and the National Foundation for Research, Technology and Development , Austria, is gratefully acknowledged. We also thank the industrial partners Mondi, Canon Production Printing, Kelheim Fibres, and SIG Combibloc for their support. Publisher Copyright: © 2021 Copyright: Copyright 2021 Elsevier B.V., All rights reserved. Hydrophobization of cellulosic materials and particularly paper products is a commonly used procedure to render papers more resistant to water and moisture. Here, we explore the hydrophobization of unsized paper sheets via the gas phase. We employed three different compounds, namely palmitoyl chloride (PCl), trifluoroacetic anhydride/acetic anhydride (TFAA/Ac2O)) and hexamethyldisilazane (HMDS) which were vaporized and allowed to react with the paper sheets via the gas phase. All routes yielded hydrophobic papers with static water contact angles far above 90° and indicated the formation of covalent bonds. The PCl and TFAA approach negatively impacted the mechanical and optical properties of the paper leading to a decrease in tensile strength and yellowing of the sheets. The HMDS modified papers did not exhibit any differences regarding relevant paper technological parameters (mechanical properties, optical properties, porosity) compared to the non-modified sheets. XPS studies revealed that the HMDS modified samples have a rather low silicon content, pointing at the formation of submonolayers of trimethylsilyl groups on the fiber surfaces in the paper network. This was further investigated by penetration dynamic analysis using ultrasonication, which revealed that the whole fiber network has been homogeneously modified with the silyl groups and not only the very outer surface as for the PCl and the TFAA modified papers. This procedure yields a possibility to study the influence of hydrophobicity on paper sheets and their network properties without changing structural and mechanical paper parameters.

Starch and derivatives thereof have proven their usefulness in paper coating processes. Among these derivatives, cationic starch has been widely used in the paper industry as a flocculation, dispersion and ink fixing agent. In another context, nanoscale cellulosic materials have been shown to improve the strength, retention of fillers, the barrier properties of packaging paper products, and printing qualities. This review summarizes the recent studies on the general components used in paper coating, describes the conventional and alternative synthetic processes of cationic starches and nanocellulose, and deals with their current and potential applications in papermaking, focusing primarily on surface treatments. Moreover, environmental applications have been considered to expand the understanding and usefulness of these materials. Further research on modified polysaccharides is encouraged to replace, in a feasible way, petro-based components of coating formulations, and to provide paper surfaces with new properties.

This study was to assess the possibility of using competitive and slow binding experiments with affinity-based ultrafiltration UPLC-QTof-MS analysis to identify potent bacterial neuraminidase (bNA) inhibitors from the Broussonetia papyrifera roots extract. To isolate unbound compounds from the enzyme-binding complex, the root bark extracts were either incubated in the absence of bNA, in the presence of bNA, or with the time-dependent bNA before the ultrafiltration was performed. Thirteen flavonoids were separated from the target extract, and their inhibitory activities were tested against bNA. The isolated flavonoids exhibited potent inhibition against NA (IC50 = 0.7–54.0 μM). Our kinetic analysis of representative active flavonoids (1, 2, and 6) showed slow and time-dependent reversible inhibition. Additionally, chalcones exhibited noncompetitive inhibition characteristics, whereas flavonols and flavans showed mixed-type behavior. The computational results supported the experimental behaviors of flavonoids 2, 6, 10, and 12, indicating that bounded to the active site, but flavonoids 6 and 10 binds near but not accurately at the active site. Although this is mixed-type inhibition, their binding can be considered competitive.

The use of non-wood fibers in the paper industry has been an economical and environmental necessity. The application of dry-strength agents has been a successful method to enhance the strength properties of paper. The experimental results evidencing the potential of chitosan and cationic starch utilization in bagasse paper subjected to hot water pre-extraction has been presented in this paper. The research analyzes the surface properties alterations due to these dry-strength agents. Inverse gas chromatography was used to evaluate the properties of surface chemistry of the papers namely the surface energy, active sites, surface area as well as the acidic/basic character. The results of the study revealed that the handsheets process causes surface arrangement and orientation of chemical groups, which induce a more hydrophobic and basic surface. The acid-base surface characteristics after the addition of dry-strength agents were the same as the bagasse handsheets with and without hot water pre-extraction. The results showed that the dry-strength agent acts as a protecting film or glaze on the surfaces of bagasse paper handsheets.

Wood from invasive tree species Acacia dealbata and Ailanthus altissima was used to produce high value-added nanocellulose. Firstly, bleached pulps were produced from the wood of these tree species after kraft cooking. Afterwards, the resultant pulps were pre-treated by TEMPO-mediated oxidation (Acacia dealbata) or enzymatic hydrolysis (Ailanthus altissima) followed by high-pressure homogenization. Hydrogels were obtained and characterized for their main physical and chemical properties, including rheology measurements. After freeze-drying, the surface properties of the materials were evaluated by inverse gas chromatography. Results showed that nano/micro fibrils could be obtained from the wood of these invasive species. Rheometry studies showed that Acacia-TEMPO cellulose nanofibrils form strong gels with high yield stress point and viscosities (reaching ca. 100,000 Pa·s). Additionally, the surfaces of the obtained nanocelluloses showed a dispersive component of the surface energy near 40 mJ/m2 and a prevalence of the Lewis acidic character over the basic one, as typical for cellulose-based materials. Finally, films with good mechanical and optical properties could be obtained from the cellulose hydrogels. Acacia-TEMPO film (produced by filtration/hot pressing) showed a tensile strength of 79 MPa, Young's modulus of 7.9 GPa, and a transparency of 88%. The water vapor barrier, however, was modest (permeability of 4.9 × 10−6 g/(Pa·day·m)).

The efficient use of waste from food processing industry is one of the innovative approaches within sustainable development, because it can be transferred into added value products, which could improve economic, energetic and environmental sectors. In this context, the squid pen waste from seafood industry was used as raw material to obtain nanofibrous β-chitin films. In order to extend functionality of obtained films, elderberry extract obtained from biomass was added at different concentrations. The tensile strength of chitin-elderberry extract films was improved by 52%, elongation at break by 153% and water vapor barrier by 65%. The obtained material showed distinct color change when subjected to acidic or basic solutions. It was proven by CIELab color analysis that all color changes could be easily perceived visually. In addition, the obtained nanofibrous film was successfully used to monitor the freshness of Hake fish. Namely, when the film was introduced in a package that contained fresh fish, its color was efficiently changed within the time during the storage at 4 °C. The obtained results demonstrated that food processing waste could be efficiently valorized, and could give sustainable food package design as a spoilage indicator of high protein food.

This work offers a facile fabrication method for lignin nanocomposites through the assembly of kraft lignin onto magnetic nanoparticles (Fe(3)O(4)) based on pH-driven precipitation, without needing organic solvents or lignin functionalization. Kraft lignin@Fe(3)O(4) multicore nanocomposites fabrication proceeded using a simple, Ph-driven precipitation technique. An alkaline solution for kraft lignin (pH 12) was rapidly injected into an aqueous-based Fe(3)O(4) nanoparticle colloidal suspension (pH 7) under constant mixing conditions, allowing the fabrication of lignin magnetic nanocomposites. The effects of increasing lignin to initial Fe(3)O(4) mass content (g/g), increasing in ratio from 1:1 to 20:1, are discussed with a complete chemical, structural, and morphological characterization. Results showed that nanocomposites fabricated above 5:1 lignin:Fe(3)O(4) had the highest lignin coverage and content (>20%), possessed superparamagnetic properties (Ms≈45,000 A·m(2)/kg(2)); had a negative surface charge (−30 mV), and formed multicore nanostructures (D(H) ≈ 150 nm). The multicore lignin@Fe(3)O(4) nanocomposites allowed rapid magnetically induced separations from suspension. After 5 min exposure to a rare-earth neodymium magnet (1.27 mm × 1.27 mm × 5.08 mm), lignin@Fe(3)O(4) nanocomposites exhibited a maximum methylene blue removal efficiency of 74.1% ± 7.1%. These nanocomposites have potential in magnetically induced separations to remove organic dyes, heavy metals, or other lignin adsorbates.

Pseudomonas chlororaphis subsp. aurantiaca DSM 19603 was cultivated on apple pulp, a glucose- and fructose-rich waste generated during juice production, to produce medium-chain length polyhydroxyalkanoates. A cell dry mass of 8.74 ± 0.20 g/L, with a polymer content of 49.25 ± 4.08% were attained. The produced biopolymer was composed of 42.7 ± 0.1 mol% 3-hydroxydecanoate, 17.9 ± 1.0 mol% 3-hydroxyoctanoate, 14.5 ± 1.1 mol% 3-hydroxybutyrate, 11.1 ± 0.6 mol% 3-hydroxytetradecanoate, 10.1 ± 0.5 mol% 3-hydroxydodecanoate and 3.7 ± 0.2 mol% 3-hydroxyhexanoate. It presented low glass transition and melting temperatures (−40.9 ± 0.7 °C and 42.0 ± 0.1 °C, respectively), and a degradation temperature of 300.0 ± 0.1 °C, coupled to a low crystallinity index (12.7 ± 2.7%), a molecular weight (Mw) of 1.34 × 105 ± 0.18 × 105 Da and a polydispersity index of 2.70 ± 0.03. The biopolymer's films were dense and had a smooth surface, as demonstrated by Scanning Electron Microscopy. They presented a tension at break of 5.21 ± 1.09 MPa, together with an elongation of 400.5 ± 55.8% and an associated Young modulus of 4.86 ± 1.49 MPa, under tensile tests. These attractive filming properties of this biopolymer could potentially be valorised in several areas such as the fine chemicals industry, biomedicine, pharmaceuticals, or food packaging.

Bacterial cellulose (BC) is a biopolymer of great significance to the medical, pharmaceutical, and food industries. However, a high concentration of carbon sources (mainly glucose) and other culture media components is usually required to promote a significant yield of BC, which increases the bioprocess cost. Thus, optimization strategies (conventional or statistical) have become relevant for the cost-effective production of bacterial cellulose. Additionally, this biopolymer may present new properties through modifications with exogenous compounds. The present review, explores and discusses recent studies (last five years) that report the optimization of BC production and its yield as well as in situ and ex situ modifications, resulting in improved mechanical, antioxidant, and antimicrobial properties of BC for new applications.

Wastewater production is rising all over the world and one of the most difficult problems is the disposal of sewage sludge (SS). It is known that SS contains certain quantities of added-value compounds, such as humic acids (HA) which in turn have beneficial effects on soil quality and plant growth. On the other hand, SS can retain many pollutants, such as heavy metals. The present work aimed to implement an HA alkaline extraction protocol from anaerobic sewage sludge (ASS). Subsequently, the HA were quantified in ASS, in HA extract and in commercial HA, used as a benchmark, which gave results of 12.53%, 26.87% and 77.87% (on dry matter basis), respectively. FESEM and EDX analyses on lyophilized HA extract confirmed that no heavy metals had passed into the extract. Afterwards, in order to allow controlled release of the HA in soils, alginate beads containing the HA extract were created. Finally, a pot experiment in a greenhouse was performed using Chilean lettuce plants (Lactuca sativa L.) treated with alginate-HA extract beads. At the end of the greenhouse experiments, the hypogean dry biomass of the treated plants was significantly higher than for non-treated plants. The relevance of this study relies not only on the exploitation of green chemistry principles, by converting a waste stream into a high-value product, but also on the application of an approach following a circular economy model.

Pressurized hot water extraction (PHWE), known as a “green” extraction technique, was used to obtain polysaccharide from the pulp of gabiroba (Campomanesia xanthocarpa Berg) fruits. The effects of pressure, temperature, and flow rate on pectin yields were analyzed through a full factorial design experiment 23. The optimal extraction conditions to achieve maximum pectin yield (5.70 wt%) were pressure of 150 bar, temperature of 120 °C, and flow rate of 1.5 mL min−1. The high pressure (100 bar) promoted an increase in galacturonic acid content (36.0%) compared to conventional hot water extraction (CEGP) with 25.7%. Differences in the proportion of homogalacturonan (HG) and rhamnogalacturonan (RG-I) domains ranging from 16.3 to 35.4% and 61.7 to 80.1%, respectively, were observed for each pectin sample according to the extraction conditions. The mono-dimensional (13C-NMR) and bi-dimensional (1H/13C HSQC-NMR) analyses confirmed the presence of HG and RG-I regions and indicated the presence of arabinogalactans type I (AG-I) and arabinogalactans type II (AG-II) in the PHWE pectin samples, which was not found for pectins from gabiroba pulp obtained by CEGP. The results showed that PHWE proved to be a promising method for extracting pectins from gabiroba fruits.

Polyhydroxyalkanoates (PHA) are natural polyesters synthesized by microbes which consume excess amount of carbon and less amount of nutrients. It is biodegradable in nature, and it synthesized from renewable resources. It is considered as a future polymer, which act as an attractive replacement to petrochemical based polymers. The main hindrance to the commercial application of PHA is the high manufacturing cost. This article provides an overview of different cost-effective substrates, their characteristics and composition, major strains involved in economical production of PHA and biosynthetic pathways leading to accumulation of PHA. This review also covers the operational parameters, various fermentative modes including batch, fed-batch, repeated fed-batch and continuous fed-batch systems, along with advanced feeding strategies such as single pulse carbon feeding, feed forward control, intermittent carbon feeding, feast famine conditions to observe their effects for improving PHA synthesis and associated challenges. In addition, it also presents the economic analysis and future perspectives for the commercialization of PHA production process thereby making the process sustainable and lucrative with the possibility of commercial biomanufacturing.

13 Pág. Instituto de Ciencias Forestales (ICIFOR), Kraft pulping, organosolv process and acid hydrolysis were applied on an elm clone. The solubilized lignins were recovered and analyzed. Kraft pulping and acid hydrolysis led to lignins with higher phenolic OH content as result of extensive cleavage of β-O-4' linkages, as revealed by 13C solid state and 13C-1H heteronuclear single quantum coherence nuclear magnetic resonance. This depolymerization also yielded lower molecular weight lignins inferred by size exclusion chromatography. Contrarily, organosolv process gave rise to a lignin with a more preserved structure, maintaining a large number of β-O-4' linkages. Consequently, organosolv lignin presented lower phenolic OH content and higher molecular weight. Moreover, the high content of the labile native β-O-4' linkages in organosolv lignin resulted in a lower thermostability as compared to the kraft and acid lignins. On the other hand, the solubilized lignins from kraft and acid processes displayed an enrichment of S-units, whereas lignin from organosolv process was slightly enriched in G-units, containing all of them different native as well as pre-treatment derived units. These results could help to increase the inventory of lignin sources available for future lignin-based products, for which knowledge of the lignin properties versus application requirements is crucial., The authors wish to thank the Comunidad de Madrid and MCIU/AEI/FEDER, UE for funding this study via Projects SUSTEC-CM S2018/EMT-4348 and RTI2018-096080-B-C22, respectively. Raquel Martín-Sampedro acknowledges an IJCI contract (IJCI-2016-28403). BW acknowledges financial support (project MAT2015-71117-R from MINECO (Spain) and FEDER (EU); and PID2019-107022RJ-I00 from MICINN (Spain)).

Technical lignins are structurally heterogeneous and polydisperse. This work describes the use of a simple and green method for lignin fractionation, using different proportions of acetone (40 and 60%) in water. Lignins from three different sources (wheat straw organosolv lignin, wheat straw soda lignin and softwood kraft lignin) were used in this fractionation protocol. The obtained fractions showed different molar mass and functional groups. The lower molar mass fractions showed more phenolic hydroxyl groups and carboxylic acid moieties than higher molar mass fractions, which also possessed much higher amounts of carbohydrates. The chemical characterization of these fractionated lignins showed that the PREC fraction was exceptionally pure and homogeneous lignin. Its total lignin content was >96% for all three lignins and it was practically free from carbohydrates and inorganics (ash). Furthermore, PREC fraction possessed the highest carbon content for the three lignin samples (63.05–69.26%). These results illustrate that the proposed aqueous acetone fractionation protocol could indeed produce pure and uniform lignin fraction and it was applicable for lignins from different sources.

In this study, microcrystalline cellulose (MCC) was extracted from roselle fiber through acid hydrolysis treatment and its properties were compared with those of commercially available MCC. The physicochemical and morphological characteristics, elemental composition, size distribution, crystallinity and thermal properties of the obtained MCC were analyzed in this work. Fourier transform infrared spectroscopy (FTIR) analysis provided clear evidence that the characteristic peak of lignin was absent in the spectrum of the MCC prepared from roselle fiber. Rough surface and slight aggregation of MCC were observed by scanning electron microscopy (SEM). Energy dispersive X-ray (EDX) analysis showed that pure MCC with small quantities of residues and impurities was obtained, with a similar elemental composition to that of commercial MCC. A mean diameter of approximately 44.28μm was measured for MCC by using a particle size analyzer (PSA). X-ray diffraction (XRD) showed the crystallinity increased from 63% in roselle pulp to 78% in roselle MCC, the latter having a slightly higher crystallinity than that of commercial MCC (74%). TGA and DSC results indicated that the roselle MCC had better thermal stability than the roselle pulp, whereas it had poorer thermal stability in comparison with commercial MCC. Thus, the isolated MCC from roselle fibers will be going to use as reinforcing element in green composites and may be a precursor for future roselle derived nanocellulose, and thus a promising subject in nanocomposite research.

The goal of this study was to investigate how the use of high concentration of cellulase may impact the properties of the substrate and the reaction medium during the enzymatic hydrolysis of the sisal pulp. Enzyme concentration of 0.9 mL g−1 was considered for hydrolysis of a sisal cellulosic substrate, and the results were compared with previous ones using 0.5 mL g−1 as cellulase concentration. Nonhydrolyzed pulps and the liquors were withdrawn from the reaction medium and characterized by scanning electron microscopy, crystallinity index, average molar mass, length/thickness, and high-performance liquid chromatography (HPLC). The results indicated that the enzyme/substrate ratio impacted crystallinity variations during the reaction and the induction period for exoglucanase action. The concentration of 0.9 mL g−1 led to a glucose yield (98%, an almost quantitative conversion) higher than 0.5 mL g−1 (89%). Aiming to gain information on the post-burst phase (after 15 h), 1 g of sisal pulp was added, and the results demonstrated that the enzymes remained active, which can counterbalance the higher cost due to the use of high enzymes concentrations. This study deepened the understanding of the enzymatic hydrolysis of sisal cellulosic pulp, and the findings may also benefit investigations on other pulps.

The process employed for the pulping and bleaching of sorghum straw was optimized prior to the synthesis of cellulose acetate. A 22 factorial central composite design was carried out. The variables considered were cooking time (1.5 to 2.5 h) and dilute alkali concentration (0.75 to 1.25%) for the pulping and bleaching time (30 to 35 min) and bleach volume (20 to 25 mL) for the bleaching. The sorghum straw was comprised of 49.43% α-cellulose, 19.18% hemicellulose and 30.42% lignin. The optimum conditions that maximize these processes were 2.5 h and 1.25% (dilute alkali concentration) at 90 °C, and 35 min and 25 mL (bleach volume) at 80 °C, respectively, providing pulps with a low Kappa number (

Four different lignin samples were isolated during the processing of rice straw for ethanol production: one after mild alkaline pretreatment (deacetylation) of rice straw, and other three after simultaneous saccharification and fermentation (fermentation residues), under different process conditions. Then, a complete chemical characterization in terms of main components (lignin, carbohydrates, among others) and elemental composition was performed for all the samples. Additionally, the structural and morphological characteristics, calorific value, thermal stability, solubility in solvents and antioxidant potential were also determined. For comparison, a standard lignin (Kraft lignin) was also assayed. The results revealed that the process used for lignin isolation has an important influence in the final properties of the sample. In general, the fermentation residues contained non-hydrolyzed polysaccharides in their composition and lower lignin content when compared to the lignin solubilized in the alkaline liquor. Among several organic solvents and mixtures, acetone 80% (v/v) was the most efficient for lignin solubilisation. Interesting properties and characteristics were observed for all the lignin samples isolated from rice straw processing, which would allow their application in different industrial areas. Based on the properties, potential applications were suggested, which could be of value for integration in biorefineries.

The increasing amount of oil wastewater is causing serious damage to the environment. Oily water is a worrisome by-product of the oil industry due to its growing volume in mature basins and complex chemical composition. Low-cost polymers are being used as alternative materials to treat oily waters after treatment by conventional methods, oil and grease (O&G) concentration being the primary parameter for final disposal. In this respect, guar gum can be used to treat petroleum-contaminated waters, with the advantage of being a low-cost, highly-hydrophilic natural polymer. In this study, guar gum, under specific conditions, shapes itself into three-dimensional structures with interesting physicochemical properties. The salting out effect occurs with reticulation of the polymeric chains by borate ions and in the presence of electrolytes, reducing the solubility of the polymeric network in the solution and leading to an electrolyte- and polymer-rich phase. When the guar gum gel was prepared in situ in the produced water, after the salting out effect, the oil was imprisoned in the interstices of the collapsed gel. The gelling guar gum was highly efficient in synthetic oily waters. In the case of initial O&G above 100 ppm, the oil removal percentage was above 90%.

Polyhydroxyalkanoates (PHA) are biodegradable and biocompatible bacterial thermoplastic polymers that can be obtained from renewable resources. The high impact of the carbon source in the final cost of this polymer has been one of the major limiting factors for PHA production and agricultural residues, mainly lignocellulosic materials, have gained attention to overcome this problem. In Brazil, production of 2nd generation ethanol from the glucose fraction, derived from sugarcane bagasse hydrolysate has been studied. The huge amounts of remaining xylose will create an opportunity for the development of other bioprocesses, generating new products to be introduced into a biorefinery model. Although PHA production from sucrose integrated to a 1G ethanol and sugar mill has been proposed in the past, the integration of the process of 2G ethanol in the context of a biorefinery will provide enormous amounts of xylose, which could be applied to produce PHA, establishing a second-generation of PHA production process. Those aspects and perspectives are presented in this article.

peer-reviewed The full text of this article will not be available in ULIR until the embargo expires on the 11/03/2020 As fossil fuel resources dwindle and new regulations for a cleaner and safer environment come on stream, there is growing interest in developing new sustainable feedstocks for future fuels, chemicals, polymers and fibers. Therefore materials research is ever more focused on the production of green or bio-based materials and their composites. Lignocellulosic biomass has become the feedstock of choice for these new materials as cellulose and lignin are the most abundant biopolymers on the planet. Lignin is a phenolic macromolecule, the principal biological source of aromatic structures, with a complex structure which varies depending on plant species and its isolation process. Despite its high carbon content and its potential as a raw material, lignin remains underutilised. Between 40 and 50 million tons of lignin are produced worldwide per year; while some is being used for low- and medium-value applications, most is currently treated as a non-commercialized by-product or as low value fuel to produce energy. However, with the emergence of biorefinery projects larger amounts of lignin with the potential for valorisation are being produced. Here, we summarise some of the latest developments in the field. peer-reviewed

The Equisetum enzyme hetero-trans-β-glucanase (HTG) covalently grafts native plant cellulose (donor-substrate) to xyloglucan (acceptor-substrate), potentially offering a novel ‘green’ method of cellulose functionalisation. However, the range of cellulosic and non-cellulosic donor substrates that can be utilised by HTG is unknown, limiting our insight into its biotechnological potential. Here we show that HTG binds all celluloses tested (papers, tissues, hydrogels, bacterial cellulose) to radioactively- or fluorescently-labelled xyloglucan-heptasaccharide (XXXGol; acceptor-substrate). Glycol-chitin, glycol-chitosan and chitosan also acted as donor substrates but less effectively than cellulose. Cellulose-XXXGol conjugates were formed throughout the volume of a block of hydrogel, demonstrating penetration. Plant-derived celluloses (cellulose Iβ) became more effective donor-substrates after ‘mercerisation’ in ≥3 M NaOH; the opposite was true for bacterial cellulose Iα. Cellulose-XXXGol bonds resisted boiling 6 M NaOH, demonstrating strong glycosidic bonding. In conclusion, HTG stably grafts native and processed celluloses to xyloglucan-oligosaccharides, which may carry valuable ‘cargoes’, exemplified by sulphorhodamine. We thus demonstrate HTG's biotechnological potential to modify various cellulose-based substrates such as textiles, pulps, papers, packaging, sanitary products and hydrogels., We thank Ms. Amy Wallace (The University of Edinburgh) for help in producing xyloglucan–[3H]XXXGol, MLG–[3H]XXXGol and cellulose–[3H]XXXGol, Dr. Tom Simmons (The University of Edinburgh) for heterologous production of EfHTG in Pichia, Ms. Lucile Druel (CEMEF, Mines ParisTech) for the preparation of cellulose hydrogels, and Ms. Anna Roig (ICMAB, Bellaterra) for help in preparing bacterial cellulose. We acknowledge The Royal Society, London, for organising a meeting (‘Cellulose: prospects and challenges’, 15–16 March 2017) which initiated part of this collaboration. This work was supported by the UK Biotechnology and Biological Sciences Research Council (BBSRC) [grant number BB/N002458/1]; and the BBSRC Impact Acceleration Account (IAA) project [grant number PIII057].

A series of novel inulin derivatives were designed and synthesized by the introduction of amino heterocyclic moieties onto carboxymethyl inulin with the aid of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide. The target products were prepared via three - step chemical synthesis, and structures were identified by FTIR and 1H NMR spectroscopy. Antioxidant activities of inulin derivatives including DPPH - radical scavenging assay, superoxide - radical scavenging assay, hydroxyl - radical scavenging assay, and reducing power were estimated. Meanwhile, their antifungal activities, including Colletotrichum lagenarium and Botrytis cinerea, were also explored by hyphal measurement. In particular, inulin derivatives bearing heterocyclic moieties exhibited a remarkable improvement over inulin on antioxidant and antifungal activities, and their bioactivities decreased roughly in the order of 2ATCMI > 4APCMI > 3APCMI > 2APCMI > 3ATCMI > CMI > inulin. Furthermore, the cytotoxicities of inulin derivatives against L929 cells were evaluated by CCK-8 in vitro, and all samples showed weak cytotoxicities. In a nutshell, the paper provides a practical approach to synthesize novel inulin derivatives with dramatically enhanced bioactivity and good biocompatibility. The product described in paper might serve as a new leading structure for further design of antioxidants or antifungal agents in biomedicine, cosmetics, and other fields.

Purine nucleotide synthesis is realised only through the salvage pathway in pathogenic bacterium Helicobacter pylori. Therefore, the enzymes of this pathway, among them also the adenylosuccinate synthetase (AdSS), present potential new drug targets. This paper describes characterization of His6-tagged AdSS from H. pylori. Thorough analysis of 3D-structures of fully ligated AdSS (in a complex with guanosine diphosphate, 6-phosphoryl-inosine monophosphate, hadacidin and Mg2+) and AdSS in a complex with inosine monophosphate (IMP) only, enabled identification of active site interactions crucial for ligand binding and enzyme activity. Combination of experimental and molecular dynamics (MD) simulations data, particularly emphasized the importance of hydrogen bond Arg135-IMP for enzyme dimerization and active site formation. The synergistic effect of substrates (IMP and guanosine triphosphate) binding was suggested by MD simulations. Several flexible elements of the structure (loops) are stabilized by the presence of IMP alone, however loops comprising residues 287–293 and 40–44 occupy different positions in two solved H. pylori AdSS structures. MD simulations discovered the hydrogen bond network that stabilizes the closed conformation of the residues 40–50 loop, only in the presence of IMP. Presented findings provide a solid basis for the design of new AdSS inhibitors as potential drugs against H. pylori.

Lignin sulfonate (LS), a waste material from the paper pulping, was modified with benzoic anhydride to obtain benzoylated lignin sulfonates of adjustable hydrophilicity (BLS). When BLS was combined with difenoconazole (Di), a broad-spectrum fungicide, lignin-based, non-crosslinked nanoparticles were obtained either by solvent exchange or solvent evaporation. When a mass ratio of 1:5 LS: benzoic anhydride was used, the Di release from Di@BLS5 after 1248 h was ca. 74 %, while a commercial difenoconazole microemulsion (Di ME) reached 100 % already after 96 h, proving the sustained release from the lignin nanocarriers. The formulation of Di in lignin-based nanocarriers also improved the UV stability and the foliar retention of Di compared to the commercial formulation of the fungicide. Bioactivity assay showed that Di@BLS5 exhibited high activities and duration against strawberry anthracnose (Colletotrichum gloeosporioides). Overall, the construction of fungicide delivery nano-platform using BLS via a simple non-crosslinked approach is a novel and promising way to develop new formulations for nanopesticide and the development of sustainable agriculture.

In this paper, the inulin derivative (3) bearing 1,2,3-triazole and diphenyl phosphate was successfully synthesized by CuAAC Click chemistry. Detailed structural characterization was determined using FTIR spectroscopy, 1H NMR spectroscopy, 13C NMR spectroscopy, and elemental analysis. The antioxidant activities against hydroxyl radicals, superoxide radicals, and DPPH radicals were estimated in vitro respectively. The results showed that the antioxidant activity of the inulin derivative (3) was significantly enhanced compared with inulin. The inulin derivative (3) exhibited stronger radical scavenging abilities, especially against hydroxyl radicals and superoxide radicals. The scavenging values of the inulin derivative (3) were 98.2% and 95.4% at 1.6 mg/mL against hydroxyl radicals and superoxide radicals respectively. Besides, the scavenging value of the inulin derivative (3) increased by about 40% to scavenge DPPH radicals at 1.6 mg/mL than inulin. The results showed that the inulin derivative (3) bearing 1,2,3-triazole and diphenyl phosphate exhibited tremendously enhanced antioxidant activity compared with inulin. The synthetic strategy might provide an effective way to prepare novel inulin antioxidant biomaterials.

Water soluble polymers and their derivatives bound to proteins can dramatically favor the biological activity of new drugs and vaccines. Quantification of the modification degree of the protein is crucial during the development and licensing phase and later in order to monitor the industrial production process and to match product specification. In this work, we describe an innovative way to measure directly the modification degree of polysialylated proteins using proton NMR (Nuclear Magnetic Resonance) spectroscopy. Following a calibration step, the modification degree can be easily deduced by the integration ratio of a separate signal from the polymer and selected signals from the protein. In fact, the upfield-shifted signals of methyl groups from Valine, Leucine and Isoleucine can be used as an internal calibration reference for the integration. In this paper recombinant factor VIII (rFVIII) and recombinant factor IX (rFIX) proteins modified by polysialic acid (PSA) are used to illustrate the accuracy, reproducibility and ease of the method that may replace or complement wet-chemistry approaches.

Amino groups on the antibody surface (amino terminus and Lys) are very interesting conjugation targets due to their substantial quantities and selectivity toward various reactive groups. Oriented immobilization of antibodies via amino moieties on the Fc region instead of the antigen-binding fragment (Fab) is highly appreciated to conserve antigen-binding capacity. In this paper, targeting amino moieties on distinct regions, three antibody immobilization strategies were compared with the recognition ability of corresponding adsorbents. Our results demonstrate that oriented immobilization of antibodies onto heterofunctional chelate-epoxy support selectively involving Lys residues placed at the bottom of the Fc region, thus preserved the highest antigen recognition capacity (over 75% functionality). For homofunctional aldehyde support, immobilization at pH 10 demonstrates 50% remaining functionality due to the random orientation of tethered antibodies; while only 10% functionality remained when N-terminus were specifically conjugated at pH 8.5. With the rationalization of moieties density onto heterofunctional support, 2-fold recognition capacity was exhibited over randomly immobilization for antigens with higher size (β-galactosidase, 425 kDa vs. horseradish peroxidase, 40 kDa). Meanwhile, at least 97% of antigens with a varied concentration in diluted human serum were efficiently captured by the optimized chelate-epoxy support. Therefore, our antibody immobilization protocol proved the potential to be utilized as a promising candidate to capture voluminous antigens (large proteins and cells) in real samples.

As one of the most promising biopolymers for a variety of potential applications, chitosan has attracted much attention because of its unique biological, chemical, and physical properties. The functionalization of chitosan has been adopted to synthesize novel chitosan derivatives with improved water-solubility and excellent biological activities. In this paper, chitosan was functionalized with a triphenylphosphonium group by means of the copper (I) catalyzed azide-alkyne “click” reaction and has been investigated as potential polymer for agricultural antifungal biomaterial. The influence of chemical modification on the structural characteristics and water-solubility of chitosan was investigated by FTIR spectroscopy, 1H NMR spectroscopy, elemental analysis, and UV–vis spectrum. Furthermore, the antifungal property of target chitosan derivative against four plant threatening fungal pathogens was evaluated and in vitro investigation demonstrated that triphenylphosphonium salt incorporated chitosan backbone had excellent antifungal property compared with chitosan and intermediate chitosan derivative. Notably, target chitosan derivative displayed relatively strongest antifungal effect with over 80% inhibitory index against Botrytis cinerea at 1.0 mg/mL. The results of a detailed antifungal study indicated that cationic chitosan derivative bearing 1,2,3-triazole and triphenylphosphonium moieties provided a promising platform for preparation of novel cationic antifungal biomaterials in the field of agriculture.

Cellulolytic enzymes have wide use in several industrial segments (e.g. biofuels, pulp and paper, food, and cosmetics). However, one of the challenges is their large-scale production with high specific activity to eliminate the dependence of the purchase of enzymatic cocktails produced by commercial parties. The aims of this study were (1) isolation, selection, and partial characterization of bacterial cellulases present in the intestinal tract of the sugarcane borer and (2) to identify cellulase-producing bacteria by analyzing the 16S rDNA gene. Cellulase production and purification assays resulted in similar electrophoretic profiles between four bacterial strains. These strains were identified as Klebsiella pneumoniae, Klebsiella sp., and Bacillus sp. K. pneumoniae was the main cellulase-producing microorganism. Our results show the possibility of finding cellulolytic microorganisms that inhabit the gut of herbivorous animals, especially those that are predators of important crops of economic value. Furthermore, K. pneumoniae cellulase is of medical importance. In hospitals, health professionals, hospital technicians, patients and visitors wear clothes containing cellulose. Thus, K. pneumoniae within hospitals can contaminate these clothes and be spread to the environment. In that case, it would be important for the hospital's chemical sterilization products to have at least one cellulase inhibitor.

Chitosan and hyaluronic acid are themost attractive natural polysaccharides used for tissue regeneration, herein innovative orthopedic coatings were constructed by dip-coating technique. Inspired by the tough nacre-like structure, multifunctional (MF) films were constructed using bioactive glass nanoparticles (BGNPs) as the inorganic phase and hyaluronic acid (HA) and chitosan (CHT) polymers as the organic phase. Polymeric (CTR) films were also builtwith both polysaccharides. Inspired by the marine mussel's adhesive proteins, itwas the first time that multilayered coatings containing both HA and CHT catechol conjugates were combined with BGNPs. Both catechol-conjugates were successful synthesized and, particularly for HA, it was possible to achieve the double of the substitution degree varying the reaction time. Prior to the LbL build-up, viscosity and Zeta potential measurements of the polyelectrolytes were conducted. The in-situ LbL growth of the films was monitored by quartz crystalmicrobalance with dissipation monitoring. Itwas found that the combination of both catechol conjugates resulted in amore compact LbL structure. Itwas also shown thatMF evidenced bioactivity, CTR presented an improved adhesion, and preliminary cellular tests confirmed the biomedical potential of these multilayered coatings being used in orthopedic implants., The authors acknowledge the Portuguese Foundation for Science and Technology (FCT) and the European program FEDER/FEEI for the financial support through projects PTDC/BTM-MAT/28123/2017 and PTDC/NAN-MAT/31036/2017. The authors also acknowledge FCT for the financial support through the exploratory project MIT-EXPL/BIO/ 0089/2017. This paper has also been prepared with the support of REMIX Project, funded by the European Union's Horizon 2020 Research and Innovation programme under the Maria Sklodowska-Curie grant agreement n. 778078.

To fight oxidative damage due to reactive oxygen species (ROS), cells are equipped of different enzymes, among which Peroxiredoxins (Prxs) (EC 1.11.1.15) play a key role. Prxs are thiol-based enzymes containing one (1-Cys Prx) or two (2-Cys Prx) catalytic cysteine residues. In 2-Cys Prxs the cysteine residues form a disulfide bridge following reduction of peroxide which is in turn reduced by Thioredoxin reductase (Tr) /Thioredoxin (Trx) disulfide reducing system to regenerate the enzyme. In this paper we investigated on Prxs of Thermus thermophilus whose genome contains an ORF TT_C0933 encoding a putative Prx, belonging to the subfamily of Bacterioferritin comigratory protein (Bcp): the synthetic gene was produced and expressed in E. coli and the recombinant protein, TtBcp, was biochemically characterized. TtBcp was active on both organic and inorganic peroxides and showed stability at high temperatures. To get insight into disulfide reducing system involved in the recycling of the enzyme we showed that TtBcp catalically eliminates hydrogen peroxide using an unusual partner, the Protein Disulfide Oxidoreductase (TtPDO) that could replace regeneration of the enzyme. Altogether these results highlight not only a new anti-oxidative pathway but also a promising molecule for possible future biotechnological applications.

In this study, the structure of inulin was chemically modified by Schiff bases in order to improve its biological activity. A total of 6 kinds of inulin derivatives were synthesized according to aza-Wittig reaction. Their structures were confirmed by FTIR, 1H NMR, and 13C NMR spectroscopy. The antioxidant activity of the inulin derivatives was evaluated in vitro. Their antifungal activities against three kinds of plant pathogenic fungi, including Botrytis cinerea, Fusarium oxysporum f. sp. cucumerium Owen, and Phomopsis asparagi, were also studied. The results showed that the biological activities of the derivatives were significantly improved compared to pure inulin. 3HBSAIL could completely scavenge hydroxyl radical and DPPH radical at 1.6mgmL-1. 3,4DHBSAIL and 2,3,4THBSAIL exhibited strong antioxidant activity as far as the four tested antioxidant systems. Moreover, the scavenging rates of 3,4DHBSAIL and 2,3,4THBSAIL against DPPH radicals were both 100% even at the lowest test concentration (0.1mgmL-1). The synthetic inulin derivatives showed a broad antifungal spectrum against the tested fungi. At 1.6mgmL-1, the inhibitory rates of 3HBSAIL against Botrytis cinerea, Fusarium oxysporum f. sp. cucumerium Owen, and Phomopsis asparagi were 93%, 83%, and 82%, respectively. The biological activities of the inulin derivatives were closely related to the DS, the number of phenolic hydroxyl groups and their substitutive positions. The products described in this paper have great potential as biomaterials with good bioactivity and biocompatibility.

The study deals with the synthesis of thermally reversible hydrogels from modified cellulose nanofibers via the Diels-Alder “click” reaction in an aqueous medium. “Never-dried” cellulose fibres derived from hardwood were submitted to shearing and surface TEMPO-oxidation before being modified with furfurylamine. The ensuing pendant furan moieties were reacted with a water-soluble bismaleimide via Diels-Alder coupling at 65 °C to produce a hydrogel, whose deconstruction was induced by the corresponding retro-Diels-Alder reaction carried out at 95 °C. Differential scanning calorimetry and rheological measurement were used to characterize the hydrogels. These aqueous cellulosic materials should provide original applications in such areas as strong paper-based artefacts and biocompatible gels.

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUG Tea industry generates many by-products which could be used to produce and incorporate bioactive tea extracts (TE) into nutraceuticals, cosmetics and/or clinical applications. However, sensibility to external factors is a major disadvantage hindering its utilization. This study deals with the implementation and characterization of suitable biopolymer delivery systems based on starch, carrageenan or alginate, as microencapsulation, to stabilize and protect TE through innovative thin-carbohydrate-coated formulations. TE were spray-dried and microencapsulated in recycled carrier materials (alginate, carrageenan or starch). Product yields varied from 55 to 58%. High microencapsulation and loading efficiencies were achieved (60–93% and 65–84%, respectively). Antioxidant capacity varied from 32 to 46 g Trolox/100 g extract, within different carrier-systems; which also showed promising rheological and UV-protective properties when transformed into gels. Total phenolic content, particle-size distribution, HPSEC-analysis, SEM-analysis and FTIR-analysis were also performed. In sum, this paper characterizes and discusses the high potential of these recycled carbohydrate-coated microparticles for future applications Ministerio de Ciencia, Innovación y Universidades | Ref. RYC2018-024454-I Xunta de Galicia | Ref. ED431F 2020/01 Xunta de Galicia | Ref. ED481B 2018/071

Nucleocapsid protein (N protein) is the primary antigen of the virus for development of sensitive diagnostic assays of COVID-19. In this paper, we demonstrate the significant impact of dimerization of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) N-protein on sensitivity of enzyme-linked immunosorbent assay (ELISA) based diagnostics. The expressed purified protein from E. coli is composed of dimeric and monomeric forms, which have been further characterized using biophysical and immunological techniques. Indirect ELISA indicated elevated susceptibility of the dimeric form of the nucleocapsid protein for identification of protein-specific monoclonal antibody as compared to the monomeric form. This finding also confirmed with the modelled structure of monomeric and dimeric nucleocapsid protein via HHPred software and its solvent accessible surface area, which indicates higher stability and antigenicity of the dimeric type as compared to the monomeric form. The sensitivity and specificity of the ELISA at 95% CI are 99.0% (94.5–99.9) and 95.0% (83.0–99.4), respectively, for the highest purified dimeric form of the N protein. As a result, using the highest purified dimeric form will improve the sensitivity of the current nucleocapsid-dependent ELISA for COVID-19 diagnosis, and manufacturers should monitor and maintain the monomer-dimer composition for accurate and robust diagnostics., Graphical abstract Unlabelled Image

Fibrinogen, a protein involved in blood coagulation, is very susceptible to oxidation. Oxidation alters its function and usually makes it more thrombogenic. Bilirubin, an end-product of the haem degradation in vertebrates, is known for its antioxidant properties. The present paper describes interaction between fibrinogen and bilirubin, and the influence of bilirubin on the formation of fibrin and protection against oxidation. The binding constant of 4.5 × 104 M−1 was determined for the fibrinogen/bilirubin complex at 37 °C. There is no change in secondary and tertiary structure of fibrinogen or its thermal stability upon bilirubin binding. The binding site of fibrinogen is not stereospecific for bilirubin and is able to accommodate both bilirubin conformers. A change in absorption maximum of bilirubin occurs upon its interaction with fibrinogen, suggesting an alteration in the conformation of bilirubin to the more cyclic one. Bilirubin exerts antioxidant effect on fibrinogen, preventing its carbonylation and aggregation. The presence of bilirubin induces the formation of fibrin with thicker fibres, as assessed by the coagulation assay. Fibrinogen and bilirubin interact at physiological concentrations, bilirubin may act as an antioxidant for fibrinogen and may modulate an important event in haemostasis, which altogether suggests possible physiological relevance of this interaction. This is the peer-reviewed version of the following article: Gligorijević, Nikola; Minić, Simeon L.; Robajac, Dragana B.; Nikolić, Milan; Ćirković-Veličković, Tanja; Nedić, Olgica, 2019. Characterisation and the effects of bilirubin binding to human fibrinogen. International Journal of Biological Macromolecules. 128, 74-79. [https://doi.org/10.1016/j.ijbiomac.2019.01.124] Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/2937]

Chemical modification is one of the prominent methods used to improve the water solubility and bioactivity of chitosan. In this paper, a series of quaternary ammonium chitosan derivatives based on 6-O-chloroacetylated chitosan (CAClC) were successfully designed and synthesized. Detailed structural characterization was carried out by means of FT-IR, 1H NMR spectroscopy, and elemental analysis. Furthermore, the antifungal activity against Botrytis cinerea, Gibberella zeae, and Physalospora piricola Nose was estimated using in vitro hypha measurements. Most of the quaternary ammonium chitosan derivatives showed an inhibitory index of >90% at 1.0 mg/mL and exhibited enhanced antifungal activity when compared to chitosan. On one hand, the higher density of positive charge contributed to the antifungal action. In addition, the inhibitory activity decreased roughly in the order of TriM [(CH3)3] > TriE [(CH2CH3)3] > TriP [(CH2CH2CH3)3] > TriB [(CH2CH2CH2CH3)3]; NNTE [(CH3)2(CH2CH3)] > NNTB [(CH3)2(CH2CH2CH2CH3)] > NNTK [(CH3)2((CH2)9CH3)] at 1.0 mg/mL. The antifungal properties of all the quaternary ammonium chitosan derivatives against the targeted fungi decreased upon increasing the alkyl chain length.

The main focus of this paper is on the improvement of formulations utilising non-conventional bio-based excipients to improve tablet release rates. Two different formulations were considered. The first formulation contains Alcell lignin, lactose monohydrate and microcrystalline cellulose as excipients and acetylsalicylic acid (aspirin) as active pharmaceutical ingredient (API). The second formulation contains lactose monohydrate and microcrystalline cellulose as excipients and aspirin as API. The prepared formulations were roller compacted followed by milling, sieving, and tableting. The tablets were then characterised in terms of dissolution rate in order to compare the release rates. Results indicated that tablets containing Alcell lignin have quicker release, faster disintegration times and higher tablet hardness for all samples with differing process parameters. Higher API dissolution has been attributed to the amorphous structure of lignin and its interaction with aspirin, which increases dissolution of the API.

Esterases are widely applied in industrial processes due to their versatility, regio- and enantioselectivity, lack of cofactors and stability in organic solvents. Bacillus licheniformis, a microorganism frequently used in industrial and biotechnological applications such as dairy, baking, beverage, pulp and paper, detergent and cosmetics production, organic synthesis and waste management, is a promising source of esterases. Here we describe the biochemical and biophysical characterization of B. licheniformis carboxylesterase BlEst1 and its SAXS-derived molecular envelope. BlEst1 has optimal hydrolytic activity against p‑nitrophenyl acetate at pH 7.0 and 40 °C. Furthermore, BlEst1 is stable in different organic solvents such as methanol, isopropanol and butanol. The BlEst1 homology model reveals a typical α/β hydrolase core with an adjacent auxiliary domain, snuggly fitting the experimental low-resolution SAXS molecular envelope. Moreover, BlEst1 maintained considerable part of its activity in the presence of up to 5 M NaCl and its thermal stability was significantly enhanced by the presence of salt, revealing its halotolerant character. The ability to work under harsh conditions makes BlEst1 an interesting candidate for industrial applications.

The influence of phenolic compounds on the enzymatic hydrolysis of cellulose was studied in depth using spectrophotometric techniques, adsorption analysis and Scanning Electron Microscopy (SEM). In this paper for the first time, both possible interactions between phenolic compounds and the enzyme or the substrate were investigated, with the use of various phenolic compounds, cellulase from T. reesei, and Avicel as cellulose source. Three classes of phenolic compounds have been identified, based on their effect on the hydrolysis of cellulose: inhibitors (quercetin, kaempferol, trans-cinnamic acid, luteolin, ellagic acid), non-inhibitors (p-coumaric acid, rutin, caffeic acid), and activators (ferulic acid, syringic acid, sinapic acid, vanillic acid). Secondly, since various structures of phenolic compounds were tested, a structure - action comprehensive correlation was possible leading to the conclusion that an -OCH3 group was necessary for the activating effect. Finally, based on the adsorption spectra and unique SEM images, a different way of adsorption (either on the enzyme or on the substrate) was noticed, depending on the activating or inhibiting action of the phenolic compound.

Corneal cross-linking (CXL) is a common surgical procedure used to modify corneal biomechanics and stabilize keratoconus progression which is still under discussion. Its side effects, which are mostly related to anatomical unpredictability and stromal exposure, are the reason for the search for new CXL agents. In this work we have quantitatively evaluated the porcine corneal stroma architecture treated with collagen crosslinking agents such as riboflavin solutions and açai extract, using second harmonic generation microscopy. Aimed at evaluating the morphological changes in the corneal stroma after collagen crosslinking under a CXL chemical agent, a tubeness filter based Hessian matrix to obtain a 3D fiber characterization of the SHG images was applied. The results showed a curling effect and shortening of the collagen fibers treated with açai as compared to the control. They also showed a higher degree of clustering of the collagen fibers with larger empty spaces when compared to the other two groups. We believe that studies such as these presented in this paper are a good direct nondestructive and free labeling evaluation technique that allows the observation of morphologic features of corneas treated with new CXL agents. Fil: Zeitoune, Angel Alberto. Universidad Nacional de Entre Ríos. Instituto de Investigación y Desarrollo en Bioingeniería y Bioinformática - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación y Desarrollo en Bioingeniería y Bioinformática; Argentina Fil: Bersanetti, Patrícia A.. Universidade Federal de Sao Paulo; Brasil Fil: Schor, Paulo. Universidade Federal de Sao Paulo; Brasil Fil: Erbes, Luciana Ariadna. Universidad Nacional de Entre Ríos. Instituto de Investigación y Desarrollo en Bioingeniería y Bioinformática - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación y Desarrollo en Bioingeniería y Bioinformática; Argentina Fil: Cesar, Carlos L.. Instituto Nacional de Fotônica Aplicada à Biologia Celular; Brasil. Universidade Federal do Ceara; Brasil Fil: Adur, Javier Fernando. Universidad Nacional de Entre Ríos. Instituto de Investigación y Desarrollo en Bioingeniería y Bioinformática - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación y Desarrollo en Bioingeniería y Bioinformática; Argentina

Large intestine cancer is one of the most relevant chronic diseases taking place at present. Despite therapies have evolved very positively, this pathology is still under deep investigation. One of the recent approaches is the prevention by natural compounds such as pectin. In this paper, we have assessed the impact of citrus pectin and modified citrus pectin on colorectal cancer in rats (Rattus norvegicus F344) to which azoxymethane and DSS were supplied. The lowest intake of food and body weight were detected in animals fed with citrus pectin, together with an increase in the caecum weight, probably due to the viscosity, water retention capacity and bulking properties of pectin. The most striking feature was that, neither citrus pectin nor modified citrus pectin gave rise to a tumorigenesis prevention. Moreover, in both, more than 50% of rats with cancer died, probably ascribed to a severe dysbiosis state in the gut, as shown by the metabolism and metagenomics studies carried out. This was related to a decrease of pH in caecum lumen and increase in acetate and lactic acid levels together with the absence of propionic and butyric acids. A relevant increase in Proteobacteria (Enterobacteriaceae) were thought to be one of the reasons for enteric infection that could have provoked the death of rats and the lack of cancer prevention. However, a reduction of blood glucose and triacylglycerides level and an increase of Bifidobacterium and Lactobacillaceae were found in animals that intake pectin, as compared to universal and modified citrus pectin feeding., Authors acknowledge the finance of this work by the Spanish Ministry of Economy, Industry and Competitiveness (Projects AGL2017-84614-C2-1-R and AGL2014-53445-R) and to the Programa de Ayudas a Grupos de Investigación del Principado de Asturias (IDI/2018/000120, Spain).

International audience; This paper reports the manufacturing by 3D printing of scaffolds for in-situ mineralization of hydroxyapatite using aqueous suspensions of alginate and polyvinyl alcohol (PVA)-grafted cellulose nanofibers (CNF). Bifunctional CNF with carboxyl and aldehyde moieties were prepared from bleached bagasse pulp and crosslinked with PVA. Aqueous hydrogels for 3D printing were prepared by directly mixing PVA-grafted CNF with sodium alginate, with and without the addition of phosphate ions. A calcium chloride solution was sprayed during the printing process in order to partially crosslink alginate and to increase the dimensional stability of the printed gel. At the end of the printing process, the prepared scaffolds were dipped into a CaCl 2 solution to: i) complete alginate crosslinking and ii) promote hydroxyapatite nucleation and growth by reaction with phosphate ions. In order to better understand the mechanisms governing manufacturing of scaffolds by 3D printing, the rheological behavior of alginate/PVA-grafted CNF and the mechanical properties of unit filaments obtained by direct hydrogel extrusion were investigated. The final scaffolds were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). This study shows that 3D printed sodium alginate/PVA-grafted CNF hydrogels are promising scaffold materials for bone tissue engineering.; Cet article rapporte la fabrication par impression 3D d'échafaudages pour la minéralisation in-situ d'hydroxyapatite à l'aide de suspensions aqueuses de nanofibres de cellulose (CNF) greffées à l'alcool polyvinylique (PVA) et d'alginate. Des CNF bifonctionnels avec des fragments carboxyle et aldéhyde ont été préparés à partir de pâte de bagasse blanchie et réticulés avec du PVA. Des hydrogels aqueux pour l'impression 3D ont été préparés en mélangeant directement du CNF greffé au PVA avec de l'alginate de sodium, avec et sans addition d'ions phosphate. Une solution de chlorure de calcium a été pulvérisée pendant le processus d'impression afin de réticuler partiellement l'alginate et d'augmenter la stabilité dimensionnelle du gel imprimé. A la fin du processus d'impression, les échafaudages préparés ont été plongés dans une solution de CaCl2 pour: i) compléter la réticulation d'alginate et ii) promouvoir la nucléation d'hydroxyapatite et la croissance par réaction avec des ions phosphate. Afin de mieux comprendre les mécanismes de fabrication des échafaudages par impression 3D, le comportement rhéologique du CNF greffé alginate / PVA et les propriétés mécaniques des filaments unitaires obtenus par extrusion directe d'hydrogel ont été étudiés. Les échafaudages finaux ont été caractérisés par microscopie électronique à balayage (MEB), spectroscopie infrarouge à transformée de Fourier (FTIR) et analyse thermogravimétrique (TGA). Cette étude montre que les hydrogels CNF greffés d'alginate de sodium / PVA imprimés en 3D sont des matériaux d'échafaudage prometteurs pour l'ingénierie tissulaire osseuse.

The determination of chitosan is a significant topic that has been growing in importance for a variety of fields. To quantify chitosan, various analytical methods can be used. When high performance liquid chromatographic (HPLC) is used for quantitative analysis of chitosan, the chitosan is mainly hydrolyzed into glucosamine salts, which are determined by HPLC. Average deacetylation degree (DD) has an effect on acid hydrolysis of chitosan. In this paper, chitosan with different average DDs was hydrolyzed to observe its effect on the determination of chitosan content, and that the study of combining acid hydrolysis rates of chitosan (α) with different average DDs and chitin (β) standard to form ratio coefficients (γ) to quantify chitosan was designed. Then, the table about γ values within certain average DD ranges of chitosan was obtained. By using γ and α, the actual content of chitosan could be obtained simply and accurately.

Due to the problems raised by the use of animal or microbial recombinant proteases, the use of proteases from vegetable origin is becoming increasingly popular.. Among them, sulfidryl proteases have a special interest. Ficin is an outstanding example of this kind of proteases. This paper aims to be to make a comprehensive review of the recent uses of this enzyme, including for example protein hydrolysis, the production of bioactive peptides and antibodies fragments (researchers point that ficin results are more reproducible than using other proteases), meat tenderization, milk coagulations in cheese making or peptide synthesis. Efforts to get industrial immobilized biocatalysts of the enzyme will be also described. The review shows the huge potential and brilliant prospect that this enzyme can have in the near future. We gratefully recognize the support from the Ministerio de Ciencia e Innovación from Spanish Government (project number CTQ2017-86170-R). The FPU fellowship (Ministerio de Educacion) for Mr. Morellon–Sterling and the fellowship for Mr. Siar from the Algerian Ministry of Higher Education and Scientific Research are also thanked.

This paper explores different film assembly conditions of the polyelectrolyte solutions of hyaluronan (HA) and chitosan (CHI), as well as both substrate and cell surface modifications, to investigate PC3 cells adhesion properties. UV-Visible, AFM-IR and Zeta potential techniques indicate that the solution ionic strength is a relevant parameter to modulate the free carboxylic groups of HA on the film surface. In addition, capacitive coupling measurements suggest that assembly conditions that favor surface charge mobility inhibit cell adhesion due to polymer rearrangements that support non-specific electrostatic interactions of positively charged CHI residues and the negatively charged cell moieties, rather than specific CD44-hyaluronan interactions. Moreover, the PC3 cells treatment with hyaluronidase and anti-CD44 antibody also highlighted the importance of CD44 binding site availability on the tumor cell adhesion properties. Finally, the conjugation of wheat germ agglutinin on the film surface proved to be a suitable strategy to boost the PC3 cell adhesion properties. Our results reveal the remarkable capacity of HA/CHI films to modulate cell-substrate properties, which pave the road for the development of surfaces suitable for several applications based on biosensing.