| 1. |
- Christakopoulos, Paul, et al.
(author)
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Antimicrobial activity of acidic xylo-oligosaccharides produced by family 10 and 11 endoxylanases
- 2003
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In: International Journal of Biological Macromolecules. - 0141-8130 .- 1879-0003. ; 31:4-5, s. 171-175
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Journal article (peer-reviewed)abstract
- Acidic oligosaccharides were obtained from birchwood xylan by treatment with a Thermoascus aurantiacus family 10 and a Sporotrichum thermophile family 11 endoxylanases. The main difference between the products liberated by xylanases of family 10 and 11 concerned the length of the products containing 4-O-methyl-d-glucuronic acid. The xylanase from T. aurantiacus liberate from glucuronoxylan an aldotetrauronic acid as the shortest acidic fragment in contrast with the enzyme from S. thermophile, which liberated an aldopentauronic acid. Acidic xylooligosaccharides were separated from the hydrolysate by anion-exchange and size-exclusion chromatography (SEC) and the primary structure was determined by 13C NMR spectroscopy. The acidic xylo-oligosaccharides were tested against three Gram-positive and three Gram-negative aerobically grown bacteria, as well as against Helicobacterpylori. Aldopentauronic acid was proved more active against the Gram-positive bacteria and against H. pylori.
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| 2. |
- Christakopoulos, Paul, et al.
(author)
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Enzymatic synthesis of trisaccharides and alkyl β-d-glucosides by the transglycosylation reaction of β-glucosidase from Fusarium oxysporum
- 1994
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In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 16:6, s. 331-334
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Journal article (peer-reviewed)abstract
- Purified β-glucosidase from Fusarium oxysporum catalyses hydrolysis and transglycosylation reactions. By utilizing the transglycosylation reaction, trisaccharides and alkyl β-d-glucosides were synthesized under optimal conditions in the presence of various disaccharides and alcohols. The yields of trisaccharides and alkyl β-d-glucosides were 22–37% and 10–33% of the total sugar, respectively. The enzyme retained 70–80% of its original activity in the presence of 25% (w/v) methanol, ethanol and propanol. Thus, β-glucosidase from F. oxysporum appears to be an ideal enzyme for the synthesis of useful trisaccharides and alkyl β-d-glucosides.
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| 3. |
- Makropoulou, M., et al.
(author)
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Factors affecting the specificity of beta-glucosidase from Fusarium oxysporum in enzymatic synthesis of alkyl-beta-D-glucosides
- 1998
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In: International Journal of Biological Macromolecules. - 0141-8130 .- 1879-0003. ; 22:2, s. 97-101
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Journal article (peer-reviewed)abstract
- Factors affecting the specificity of β-glucosidase from Fusarium oxysporum in enzymatic synthesis of alkyl-β-d-glucosidesFusarium oxysporumβ-glucosidase has been used to catalyze the production of alkyl-β-d-glucosides from various disaccharides, based on the transglucosylation reaction, in the presence of primary, secondary and tertiary alcohols as glucosyl acceptors. Primary alcohols were found to be the best acceptors. The influence of the glucosyl donor concentration, as well as the enzyme specificity towards the cleaved glucosidic bond and the aglucone part of the donor, have also been investigated. The enzyme does not exhibit regiospecificity and seems to be unspecific towards the aglucone part. The specificity of the β linkage has been confirmed by proton nuclear magnetic resonance (1H NMR) analysis.
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| 4. |
- Rosdahl, Hans, et al.
(author)
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A microdialysis method for the in situ investigation of the action of large peptide molecules in human skeletal muscle : detection of local metabolic effects of insulin.
- 2000
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In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 28:1, s. 69-73
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Journal article (peer-reviewed)abstract
- The possibility of using microdialysis catheters with a large pore size dialysis membrane (100 kDa) to investigate the action of macromolecules perfused into the interstitial space of peripheral tissues was explored. This was made possible by increasing the colloid osmotic pressure of the perfusate with 40 g/l of dextran-70 to prevent perfusate loss across the dialysis membranes. Microdialysis catheters were inserted into the quadriceps femoris muscle of 13 human subjects. With different perfusion flow rates (1. 33, 0.66, 0.33 and 0.16 microl/min) the recorded concentrations of glucose, lactate, and urea were in agreement with values previously obtained using a conventional membrane with a smaller pore size (20 kDa) [Rosdahl H, Hamrin K, Ungerstedt U, Henriksson. J Am J Physiol 1998;274:E936-45.]. When insulin was added to the perfusate, the concentration of glucose was significantly reduced, indicating that insulin diffuses across the dialysis membrane and has cellular effects that can be simultaneously recorded. The present findings are the first documentation on the use of microdialysis to study the local metabolic action of large peptide molecules in human tissues and may open new avenues for in-vivo metabolic research.
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| 5. |
- Sanakis, Y., et al.
(author)
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Catechol 1,2-dioxygenase from Pseudomonas putida in organic media : an electron paramagnetic resonance study
- 2003
-
In: International Journal of Biological Macromolecules. - 0141-8130 .- 1879-0003. ; 33:1-3, s. 101-106
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Journal article (peer-reviewed)abstract
- The ability of an isolated isozyme of catechol 1,2-dioxygenase from Pseudomonas putida DSM 437 to function in a non-aqueous environment was investigated. The lyophilized enzyme is able to keep its catalytic function catalyzing the oxidation of catechol in n-hexane. Electron paramagnetic resonance (EPR) spectroscopy at liquid helium temperatures was applied to compare the properties of the non-heme iron of the enzyme in the organic solvent and in the aqueous solution. The catalytic performance of the enzyme in the organic solvent is correlated with the spectroscopic properties of the non-heme iron.
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| 6. |
- Vardakou, Maria, et al.
(author)
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Mode of action of family 10 and 11 endoxylanases on water-unextractable arabinoxylan
- 2003
-
In: International Journal of Biological Macromolecules. - 0141-8130 .- 1879-0003. ; 33:1-3, s. 129-134
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Journal article (peer-reviewed)abstract
- Microbial endo-β-1,4-xylanases (EXs, EC 3.2.1.8) belonging to glycanase families 10 and 11 differ in their action on water-unextractable arabinoxylan (WU-AX). WU-AX was incubated with different levels of a Thermoascus aurantiacus family 10 and a Sporotrichum thermophile family 11 endoxylanases. At 10 g l−1 arabinoxylan, enzyme concentrations (KE values) needed to obtain half-maximal hydrolysis rates (Vmax values) were 4.4 nM for the xylanase from T. aurantiacus and 7.1 nM for the xylanase from S. thermophile. Determination of Vmax/KE revealed that the family 10 enzyme hydrolysed two times more efficiently WU-AX than the family 11 enzyme. Molecular weights of the products formed were assessed and separation of feruloyl-oligosaccharides was achieved by anion-exchange and size-exclusion chromatography (SEC). The main difference between the feruloylated products by xylanases of family 10 and 11 concerned the length of the products containing feruloyl-arabinosyl substitution. The xylanase from T. aurantiacus liberated from WU-AX a feruloyl arabinoxylodisaccharide (FAX2) as the shortest feruloylated fragment in contrast with the enzyme from S. thermophile, which liberated a feruloyl arabinoxylotrisaccharide (FAX3). These results indicated that different factors govern WU-AX breakdown by the two endoxylanases.
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| 7. |
- Abdollahi, Mehdi, 1985, et al.
(author)
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Carboxymethyl cellulose-agar biocomposite film activated with summer savory essential oil as an antimicrobial agent
- 2019
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In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 126, s. 561-568
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Journal article (peer-reviewed)abstract
- Carboxymethyl cellulose (CMC)-agar biocomposite film was developed by a solvent casting method and the effects of summer savory essential oil (SSEO) at 0.5, 1.0 and 1.5% v/v on antimicrobial, microstructural, mechanical and optical properties as well as water sensitivity of the films were studied. Results showed that incorporation of SSEO into the biocomposite film developed active films with good antimicrobial agent growth inhibition activity against Gram-positive bacteria (S. aureus, B. cereus and L. monocytogenes) and less powerfully against Gram-negative bacteria (E. coli). Addition of the SSEO at 1.0 and 1.5% increased microstructural heterogeneity of the films and hence significantly (p < 0.05) increased water vapor permeability of the films while reducing their tensile strength. In contrast, mechanical flexibility and surface hydrophobicity of the films was significantly (p < 0.05) improved as a function of SSEO addition. The active films showed substantially lower swelling ratio compared to the CMC-agar film when 1.5% SSEO was added, but the transparency of the films was reduced. Finally, the results showed that SSEO can act as an antimicrobial agent in combination with CMC-agar film. However, it modifies properties of the film depending on the applied concentration.
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| 8. |
- Abdollahi, Mehdi, 1985, et al.
(author)
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Reducing water sensitivity of alginate bio-nanocomposite film using cellulose nanoparticles
- 2013
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In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 54:1, s. 166-173
-
Journal article (peer-reviewed)abstract
- A bio-based nanocomposite was developed by incorporation of cellulose nanoparticles (CN) obtained from sulfuric acid hydrolysis into alginate biopolymer using solution casting method. The effect of CN loading content (1, 3, 5 and 10 wt%) on microstructural, physical, mechanical and optical properties of the nanocomposites were characterized. The results showed that water solubility and water vapor permeability of the nanocomposites decreased by about 40% and 17%, respectively, upon increasing the CN content to 10%. In addition, the crystalline structure of the CN increased surface hydrophobicity of the alginate film by about 98%. The tensile strength value of the composite films increased from 18.03 to 22.4 MPa with increasing NC content from 0 to 5%; but, it decreased with further increase of the filler content. Nevertheless, film transparency decreased with CN incorporation, especially in high level (10%), which suggested the occurrence of partial agglomeration of the fillers at 10% that coincided with microstructural and mechanical results.
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| 9. |
- Agustin, Melissa B., et al.
(author)
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Enzymatic crosslinking of lignin nanoparticles and nanocellulose in cryogels improves adsorption of pharmaceutical pollutants
- 2024
-
In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 266
-
Journal article (peer-reviewed)abstract
- Pharmaceuticals, designed for treating diseases, ironically endanger humans and aquatic ecosystems as pollutants. Adsorption-based wastewater treatment could address this problem, however, creating efficient adsorbents remains a challenge. Recent efforts have shifted towards sustainable bio-based adsorbents. Here, cryogels from lignin-containing cellulose nanofibrils (LCNF) and lignin nanoparticles (LNPs) were explored as pharmaceuticals adsorbents. An enzyme-based approach using laccase was used for crosslinking instead of fossil-based chemical modification. The impact of laccase treatment on LNPs alone produced surface-crosslinked water-insoluble LNPs with preserved morphology and a hemicellulose-rich, water-soluble LNP fraction. The water-insoluble LNPs displayed a significant increase in adsorption capacity, up to 140 % and 400 % for neutral and cationic drugs, respectively. The crosslinked cryogel prepared by one-pot incubation of LNPs, LCNF and laccase showed significantly higher adsorption capacities for various pharmaceuticals in a multi-component system than pure LCNF or unmodified cryogels. The crosslinking minimized the leaching of LNPs in water, signifying enhanced binding between LNPs and LCNF. In real wastewater, the laccase-modified cryogel displayed 8–44 % removal for cationic pharmaceuticals. Overall, laccase treatment facilitated the production of bio-based adsorbents by improving the deposition of LNPs to LCNF. Finally, this work introduces a sustainable approach for engineering adsorbents, while aligning with global sustainability goals.
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| 10. |
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| 11. |
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| 12. |
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| 13. |
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| 14. |
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| 15. |
- Amir, Mohd., et al.
(author)
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Investigating architecture and structure-function relationships in cold shock DNA-binding domain family using structural genomics-based approach
- 2019
-
In: International Journal of Biological Macromolecules. - : ELSEVIER SCIENCE BV. - 0141-8130 .- 1879-0003. ; 133, s. 484-494
-
Journal article (peer-reviewed)abstract
- Oligonucleotide/oligosaccharide-binding fold (OB-fold) plays a major role in the regulation of central dogma of life via binding though DNA and RNA. The OB-fold domains are diverse in nature and present in large number of proteins with verities of molecular functions. Here, we have investigated the distribution of sequence, structure and repeats of cold shock DNA-binding proteins (CSDB), a member of OB-fold, in all three kingdoms to establish functional relationships. The CSDB is consists of 30 domains with a major contribution of S1 (>110,601 sequences), S12 (>23,760 sequences), S17 (>14,833 sequences) and S28e (>1615 sequence) domains. These domains are largely found in bacteria (70-90%). The number of S1 domain repeats in eukaryota varies from 1 to 15 and are well-correlated with the protein size. The molecular function analysis suggests that a large number of repeats in the S1 domain are involved in diverse molecular functions in bacteria and eukaryotes. In-depth structure analysis of Si, S12, S17 and S28e domain-containing proteins of the OB-fold family provides a reasonable basis to understand the relationship of size and number of repeats with the corresponding molecular functions.
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| 16. |
- Bahari, Helma Sadat, et al.
(author)
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Chitosan nanocomposite coatings with enhanced corrosion inhibition effects for copper
- 2020
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In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 162, s. 1566-1577
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Journal article (peer-reviewed)abstract
- A biopolymer coating on copper was prepared based on chitosan nanocomposite and its corrosion inhibition efficiency was investigated. Inclusion of silica nanoparticles substantially reduces swelling ratio of chitosan coating while enhancing its thermal stability. The corrosion resistance of chitosan-based coatings is improved by introducing 2-mercaptobenzothiazole and silica in the matrix. It is found that upon crosslinking the chitosan coatings, a higher corrosion resistance could be achieved and the highest inhibition efficiency for chitosan nanocomposite coatings is calculated as 85%. The corrosion mechanism is found closely related to mass transition and diffusion process, and also the polarization resistance contributes to the impedance. Calculated impedance using Kramers-Kronig transformation shows good agreement with experimental values, thus validating the impedance measurements. This study exhibits the enhanced efficiency of nanocomposite and potential of chitosan coatings in corrosion prevention for copper.
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| 17. |
- Barbera, Stefano, et al.
(author)
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Dimerization of the C-type lectin-like receptor CD93 promotes its binding to Multimerin-2 in endothelial cells
- 2023
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In: International Journal of Biological Macromolecules. - : Elsevier. - 0141-8130 .- 1879-0003. ; 224, s. 453-464
-
Journal article (peer-reviewed)abstract
- Blocking the signaling activated by the plasma membrane receptor CD93 has recently been demonstrated a useful tool in antiangiogenic treatment and oncotherapy. In the proliferating endothelium, CD93 regulates cell adhesion, migration, and vascular maturation, yet it is unclear how CD93 interacts with the extracellular matrix activating signaling pathways involved in the vascular remodeling. Here for the first time we show that in endothelial cells CD93 is structured as a dimer and that this oligomeric form is physiologically instrumental for the binding of CD93 to its ligand Multimerin-2. Crystallographic X-ray analysis of recombinant CD93 reveals the crucial role played by the C-type lectin-like and sushi-like domains in arranging as an antiparallel dimer to achieve a functional binding state, providing key information for the future design of new drugs able to hamper CD93 function in neovascular pathologies.
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| 18. |
- Basu, Santanu
(author)
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Improved postharvest quality of apple (Rich Red) by composite coating based on arabinoxylan and beta-glucan stearic acid ester
- 2020
-
In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 151, s. 618-627
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Journal article (peer-reviewed)abstract
- Apples (Rich Red) were coated with wheat straw arabinoxylan (AX) and beta-glucan stearic acid ester (SABG) composite coating material in the concentration range of 1-2%. The postharvest storage life of coated apples was studied at 22 degrees C (+/- 2) with 65% and 85% relative humidity for 45 days. Application of both AX-SABG (1-2%) and shellac (1-2%) coatings material significantly reduced the weight loss, respiration process, color degradation, process of fruit softening and ripening index as compared to the uncoated apples up to 30 days storage. However, the AX-SABG coatings were found more effective in preventing the aroma loss, reducing microbial spoilage and maintaining sensorial attributes as compared to shellac and uncoated apples during storage. (C)2020 Elsevier B.V. All rights reserved.
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| 19. |
- Bertoft, Eric, et al.
(author)
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Building block organisation of clusters in amylopectin from different structural types
- 2012
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In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 50, s. 1212-1223
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Journal article (peer-reviewed)abstract
- Clusters of chains consisting of tightly branched units of building blocks were isolated from 10 amylopectin samples possessing the 4 types of amylopectin with different internal unit chain profiles previously described. It was shown that clusters in types 1 and 2 amylopectins are larger than in types 3 and 4, but the average cluster size did not correspond to the ratio of short to long chains of the amylopectins. The size-distribution of the building blocks, having one or several branches, possessed generally only small differences between samples. However, the length of the interblock segments followed the type of amylopectin structure, so that type 1 amylopectins had shortest and type 4 the longest segments. The chains in the clusters were divided into characteristic groups probably being involved in the interconnection of two, three, and four - or more - building blocks. Long chains were typically found in high amounts in clusters from type 4 amylopectins, however, all cluster samples contained long chains. The results are discussed in terms of the building block structure of amylopectin, in which the blocks together with the interblock segments participate in a branched backbone building up the amorphous lamellae inside growth rings of the starch granules. In such a model, amylopectins with proportionally less long chains (types 1 and 2) possess a more extensively branched backbone compared to those with more long chains (types 3 and 4). (C) 2012 Elsevier B.V. All rights reserved.
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| 20. |
- Bertoft, Eric
(author)
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Phosphate esters in amylopectin clusters of potato tuber starch
- 2011
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In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 48, s. 639-649
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Journal article (peer-reviewed)abstract
- Starch phosphate is important in starch metabolism and in order to deduce its location and structural effects in clusters and building blocks of amylopectin, these were isolated from a normal potato (WT) and two starches with antisense suppressed glucan water dikinase (asGWD) activity and starch branching enzyme (asSBE) activity possessing suppressed and increased phosphate contents, respectively. Neutral N-chains and phosphorylated P-chains of the amylopectin macromolecules were similar in WT and asGWD, whereas asSBE possessed considerably longer P-chains. Cluster beta-limit dextrins were isolated by alpha-amylase treatment and successive B-amylolysis. Cluster sizes were generally smaller in asSBE. The building block composition of neutral N-clusters were very similar in WT and asGWD, while asSBE was different, containing less blocks with degree of polymerization (DP) > 14. Phosphate content of the P-clusters of WT and asGWD was rather similar, while asSBE contained highly phosphorylated P-clusters with proportionally more P-chains and a low degree of branching. The average chain lengths of the P-clusters were, however, similar in all samples. Our data demonstrate only minor effect on the cluster structure in relation to phosphate deposition suggesting conserved reaction patterns of starch phosphorylation. Models are suggested to account for the principle structural and functional effects of starch phosphate esters. (C) 2011 Elsevier B.V. All rights reserved.
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| 21. |
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| 22. |
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| 23. |
- Bertoft, Eric
(author)
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The fine structure of cassava starch amylopectin Part 1: Organization of clusters
- 2010
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In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 47, s. 317-324
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Journal article (peer-reviewed)abstract
- The enzyme alpha-amylase from Bacillus subtilis was applied to partly hydrolyze purified cassava amylopectin into groups of clusters, which were called domains. The domains were further size-fractionated by methanol precipitation and then subjected to a second stage of alpha-amylolysis until the rate of hydrolysis was slow in order to release the single clusters. All domain and cluster fractions were hydrolyzed with beta-amylase into beta-limit dextrins. The size distribution and chain composition of the beta-limit dextrins were analyzed by gel-permeation chromatography and high-performance anion-exchange chromatography with pulsed amperometric detection, respectively. The sizes of the clusters in the form of beta-limit dextrins were uniform with an average degree of polymerization of 67-78. The distribution profiles of B-chains were similar in all cluster fractions, which suggested that the internal structure of the cassava amylopectin clusters was homogenous. Long B-chains were involved in the interconnection of clusters in the domain fractions. These were cleaved and a new group of chains of intermediate length was produced by the alpha-amylase together with short chains. In the isolated clusters, however, some chains corresponding to long B-chains still remained, which is not predicted by the traditional cluster model of the amylopectin structure. Instead, the alternative two-directional backbone model could explain the mode of interconnection between the clusters. (C) 2010 Elsevier B.V. All rights reserved.
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| 24. |
- Bertoft, Eric
(author)
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The fine structure of cassava starch amylopectin. Part 2: Building block structure of clusters
- 2010
-
In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 47, s. 325-335
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Journal article (peer-reviewed)abstract
- The aim of this work was to analyse the organization of unit chains inside clusters of cassava amylopectin. beta-Limit dextrins of the clusters and partly fragmented clusters (sub-clusters) were isolated previously [Laohaphatanaleart et al., Int. J. Biol. Macromol. (2010) doi:10.1016/j.ijbiomac.2010.01.0049] and were now hydrolysed extensively with the alpha-amylase (liquefying type) of Bacillus subtilis into small, branched building blocks. The blocks were size-fractionated and characterized structurally. The smallest blocks predominated in the clusters. They were single branched and possessed a degree of polymerization (DP) of 5-9. Blocks with DP 10-15 were double branched and constituted the second largest group. The clusters of cassava amylopectin, which were of rather uniform size, possessed typically 7-9 building blocks, and all clusters contained similar size-distributions of the blocks. The inter-block chain length was 7-8 residues. The possible mode of attack by the enzyme between the building blocks is discussed. A model of the building block organization in the clusters is presented, in which the structural roles of different subgroups of clustered chains are suggested. A three-dimensional model suggests a possible organization of the building blocks inside the amorphous lamellae in the granular starch. (C) 2010 Elsevier B.V. All rights reserved.
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| 25. |
- Bhattacharjee, Snehasish, et al.
(author)
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Importance of the hydroxyl substituents in the B-ring of plant flavonols on their preferential binding interactions with VEGF G-quadruplex DNA : Multi-spectroscopic and molecular modeling studies
- 2018
-
In: International Journal of Biological Macromolecules. - : Elsevier. - 0141-8130 .- 1879-0003. ; 118, s. 629-639
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Journal article (peer-reviewed)abstract
- G-quadruplex (G4) structures are known to be promising anticancer drug targets and flavonols (an important class of fiavonoids) are small molecules reported to possess several health-promoting properties including those of anticancer activities. In this work, we explored the interactions of the structurally related plant flavonols kaempferol (KAE; 3,5,7,4'-OH flavone) and morin (MOR; 3,5,7,2',4'-OH flavone) with various G4-DNA sequences along with duplex DNA using a combination of spectroscopic and molecular docking studies. Our results revealed that KAE shows preferential interaction with VEGF G4-DNA in comparison to the other G4 sequences and duplex DNA. Moreover, KAE enhances the thermal stability of VEGF G4-DNA. In contrast, MOR exhibits an appreciably weaker level of interaction with both duplex and various G4-DNAs, with no significant structural specificity. The contrasting DNA binding behaviors suggest a crucial role of the 2'-OH substituent in the Bring of flavonol moiety. While KAE is relatively planar, MOR adopts a significantly non-planar conformation attributable to steric hindrance from the additional 2'-OH substituent. This small structural difference is apparently very important for the ability of KAE and MOR to interact with VEGF G4-DNA. Thus, KAE (but not MOR) appears to be an effective ligand for VEGF G4-DNA, opening up possibilities of its application for regulation of gene expression in cancer cells.
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| 26. |
- Biscari, Giuseppina, et al.
(author)
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Gellan gum-dopamine mediated in situ synthesis of silver nanoparticles and development of nano/micro-composite injectable hydrogel with antimicrobial activity
- 2024
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In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 258
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Journal article (peer-reviewed)abstract
- Infected skin wounds represent a serious health threat due to the long healing process and the risk of colonization by multi-drug-resistant bacteria. Silver nanoparticles (AgNPs) have shown broad-spectrum antimicrobial activity. This study introduces a novel approach to address the challenge of infected skin wounds by employing gellan gum-dopamine (GG-DA) as a dual-functional agent, serving both as a reducing and capping agent, for the in situ green synthesis of silver nanoparticles. Unlike previous methods, this work utilizes a spray-drying technique to convert the dispersion of GG-DA and AgNPs into microparticles, resulting in nano-into-micro systems (AgNPs@MPs). The microparticles, with an average size of approximately 3 μm, embed AgNPs with a 13 nm average diameter. Furthermore, the study explores the antibacterial efficacy of these AgNPs@MPs directly and in combination with other materials against gram-positive and gram-negative bacteria. The versatility of the antimicrobial material is showcased by incorporating the microparticles into injectable hydrogels. These hydrogels, based on oxidized Xanthan Gum (XGox) and a hyperbranched synthetic polymer (HB10K-G5-alanine), are designed with injectability and self-healing properties through Shiff base formation. The resulting nano-into-micro-into-macro hybrid hydrogel emerges as a promising biomedical solution, highlighting the multifaceted potential of this innovative approach in wound care and infection management.
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| 27. |
- Botta, Luigi, et al.
(author)
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Biocomposite PBAT/lignin blown films with enhanced photo-stability
- 2022
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In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 217, s. 161-170
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Journal article (peer-reviewed)abstract
- Lignin can be obtained as a byproduct during cellulose-rich pulp fibers production and it is habitually treated as waste or intended for low-value destinations. However, due to UV absorption and mechanical properties, lignin can contribute to the fabrication of biodegradable blown films with superior performances. In this study, it was established the suitability of lignin for manufacturing biocomposite PBAT blown films with higher stiffness and photo-oxidation resistance. The effect of the filler concentration on the melt rheological behavior in non-isothermal elongational flow was investigated. The results allowed us to choose the correct filler concentration for producing films through a film blowing operation. The PBAT/lignin blown film composites displayed an increase of the elastic modulus if compared to neat PBAT films without affecting their elongation at break. Furthermore, the filler delayed the photo-oxidative degradation of PBAT hence potentially allowing open-air applications.
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| 28. |
- Cano, María Emilia, et al.
(author)
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Characterization of carboxylated cellulose nanofibrils and oligosaccharides from Kraft pulp fibers and their potential elicitor effect on the gene expression of Capsicum annuum
- 2024
-
In: International Journal of Biological Macromolecules. - : Elsevier B.V.. - 0141-8130 .- 1879-0003. ; 267
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Journal article (peer-reviewed)abstract
- Biomass-derived oligo- and polysaccharides may act as elicitors, i.e., bioactive molecules that trigger plant immune responses. This is particularly important to increase the resistance of plants to abiotic and biotic stresses. In this study, cellulose nanofibrils (CNF) gels were obtained by TEMPO-mediated oxidation of unbleached and bleached kraft pulps. The molecular structures were characterized with ESI and MALDI MS. Analysis of the fine sequences was achieved by MS and MS/MS of the water-soluble oligosaccharides obtained by acid hydrolysis of the CNF gels. The analysis revealed the presence of two families: one corresponding to homoglucuronic acid sequences and the other composed by alternating glucose and glucuronic acid units. The CNF gels, alone or with the addition of the water-soluble oligosaccharides, were tested on Chili pepper (Capsicum annuum). Based on the characterization of the gene expression with Next Generation Sequencing (NGS) of the C. annuum’s total messenger RNA, the differences in growth of the C. annuum seeds correlated well with the downregulation of the pathways regulating photosynthesis. A downregulation of the response to abiotic factors was detected, suggesting that these gels would improve the resistance of the C. annuum plants to abiotic stress due to, e.g., water deprivation and cold temperatures.
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| 29. |
- Carlstedt, Jonas, et al.
(author)
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Release of DNA from surfactant complexes induced by 2-hydroxypropyl-beta-cyclodextrin.
- 2010
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In: International Journal of Biological Macromolecules. - : Elsevier BV. - 1879-0003 .- 0141-8130. ; 46:2, s. 153-158
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Journal article (peer-reviewed)abstract
- Decompaction of DNA-CTA self-assembled complexes by 2-hydroxypropyl-beta-cyclodextrin (2-HP-beta-CD) was studied and the results were compared with beta-CD. Different degrees of 2-HP substitution (0.6, 0.8 and 1.0, respectively) were used and the decompaction was successful with all degrees of substitution. Fluorescence microscopy, steady state fluorescence spectroscopy, density and sound velocity measurements, thermal melting and circular dichroism were used. Compared to previous work using alpha- and beta-CD, the fluorescence spectroscopy results showed that the 2-HP-substituted CDs more efficiently released DNA into solution. Furthermore, dissociation of macroscopically phase separated DNA-CTA complexes was achieved upon addition of 2-HP-beta-CD and the results gave strong indications on the non-equilibrium nature of the system. The globule-to-coil transition was not found to proceed through a coexistence region, which seems to be a general phenomenon in DNA decompaction using CDs.
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| 30. |
- Castro Alves, Victor, 1986-, et al.
(author)
-
Characterization and immunomodulatory effects of glucans from Pleurotus albidus, a promising species of mushroom for farming and biomass production
- 2017
-
In: International Journal of Biological Macromolecules. - : Elsevier. - 0141-8130 .- 1879-0003. ; 95, s. 215-223
-
Journal article (peer-reviewed)abstract
- Polysaccharides from a number of mushroom species are recognized as functional food ingredients with potential health benefits, including immunomodulatory effects. In this study, polysaccharides extracted from the basidiome with cold water (BaCW), hot water (BaHW), and hot alkali (BaHA) solution, and exo-(MyEX) and endopolysaccharides (MyEN) from the submerged culture of Pleurotus albidus, a promising species for farming and biomass production, were analyzed for their chemical composition and structure and immunomodulatory effects on macrophages. Compositional (HPAEC-PAD and HPSEC-RID/MWD) and structural (FT-IR, 1D- and 2D-NMR) analyses identified BaCW and MyEX as beta-(1,6)-branched beta-(1,3)-glucans, BaHW and MyEN as alpha-(1,3)-(1,2)-branched alpha-(1,6)-glucans, and BaHA as a mixture of alpha-(1,6) and beta-(1,3)-glucans. BaCW and MyEX stimulated the production of tumor necrosis factor alpha (TNF-alpha) and nitric oxide (NO), but not interleukin-6 (IL-6), and decreased phagocytosis of zymosan particles. In contrast, BaHW and MyEN induced TNF-alpha, NO and IL-6 production, and increased zymosan phagocytosis, while BaHA displayed intermediary effects in comparison the other polysaccharides. In conclusion, the basidiome and the submerged culture of P. albidus are sources of easily extractable alpha- and beta-glucans with potential immunomodulatory effects.
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| 31. |
- Castro Alves, Victor, 1986-, et al.
(author)
-
Polysaccharides from chayote enhance lipid efflux and regulate NLRP3 inflammasome priming in macrophage-like THP-1 cells exposed to cholesterol crystals
- 2019
-
In: International Journal of Biological Macromolecules. - : Elsevier. - 0141-8130 .- 1879-0003. ; 127, s. 502-510
-
Journal article (peer-reviewed)abstract
- The contribution of dietary fiber to decrease the risk of atherosclerosis may occur through other mechanisms besides the increased excretion of cholesterol. Although macrophages are crucial for lipid clearance, the excessive uptake of cholesterol crystals (CC) by these cells induce NLRP3 inflammasome and foam cell formation. Thus, we investigated whether the water-soluble DF from chayote (WSP) regulate CC-pretreated macrophage-like THP-1 cells. Linkage analysis indicated that WSP is composed mainly of pectic homogalacturonan and highly branched type I rhamnogalacturonan as well as hemicellulosic material including glucomannan, xyloglucan, and glucurono(arabino)xylan. WSP reduced interleukin (IL)-1β and chemokine release in CC-pretreated macrophages. Notably, WSP also reduced lipid accumulation in cells previously exposed to CC. Furthermore, WSP upregulated liver X receptor alpha expression, which may account for increased lipid efflux, and reduced matrix metallopeptidase 9 expression. WSP also reduced active caspase-1 protein levels, and downregulated NLRP3 and IL-1β gene expression in CC-pretreated cells, suggesting that this polysaccharide fraction regulates the priming signals required for NLRP3 inflammasome activation. Thus, WSP regulate lipid efflux and suppress inflammasome priming in macrophages, suggesting that the health benefits of this dietary fiber could go beyond its physical properties on the gastrointestinal tract.
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| 32. |
- Castro Alves, Victor, 1986-, et al.
(author)
-
α-and β-D-Glucans from the edible mushroom Pleurotus albidus differentially regulate lipid-induced inflammation and foam cell formation in human macrophage-like THP-1 cells
- 2018
-
In: International Journal of Biological Macromolecules. - : Elsevier. - 0141-8130 .- 1879-0003. ; 111, s. 1222-1228
-
Journal article (peer-reviewed)abstract
- Macrophages play an essential role in lipid metabolism; however, the excessive uptake of modified lipids andcholesterol crystals (CC) leads to the formation of pro-inflammatory lipid-laden macrophages called foam cells.Since theα-1,6- andβ-1,3-D-glucans from the basidiome and the mycelium of the edible mushroomPleurotusalbidushave previously been shown to regulate macrophage function, these glucans were tested in macro-phage-like THP-1 cells previously exposed to acetylated low-density lipoproteins (acLDL) or CC. The glucansinhibited lipid-induced inflammation, but only theβ-1,3-D-glucan regulated both the NLRP3 inflammasome ac-tivation and the expression of genes involved on lipid efflux in acLDL- or CC-pretreated cells, thereby reducingfoam cell formation. In contrast, the twoα-1,6-glucans tested inhibited foam cell formation only in acLDL-pretreated cells and had no effect on the expression of the peroxisome proliferator-activated receptor gammaand liver X receptor alpha genes, suggesting that these glucans regulate lipid influx rather than lipid efflux.Thus,α-andβ-D-glucans differentially regulate lipid-induced inflammation and foam cell formation in macro-phage-like cells. Furthermore, results emphasize thatP. albidushas potential to be used as a functional food oras a source for the extraction of biologically-active glucans.
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| 33. |
- Chaudhary, Amit, et al.
(author)
-
Correlating multi-functional role of cold shock domain proteins with intrinsically disordered regions
- 2022
-
In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 220, s. 743-753
-
Research review (peer-reviewed)abstract
- Cold shock proteins (CSPs) are an ancient and conserved family of proteins. They are renowned for their role in response to low-temperature stress in bacteria and nucleic acid binding activities. In prokaryotes, cold and non-cold inducible CSPs are involved in various cellular and metabolic processes such as growth and development, osmotic oxidation, starvation, stress tolerance, and host cell invasion. In prokaryotes, cold shock condition reduces cell transcription and translation efficiency. Eukaryotic cold shock domain (CSD) proteins are evolved form of prokaryotic CSPs where CSD is flanked by N- and C-terminal domains. Eukaryotic CSPs are multi-functional proteins. CSPs also act as nucleic acid chaperons by preventing the formation of secondary structures in mRNA at low temperatures. In human, CSD proteins play a crucial role in the progression of breast cancer, colon cancer, lung cancer, and Alzheimer's disease. A well-defined three-dimensional structure of intrinsically disordered regions of CSPs family members is still undetermined. In this article, intrinsic disorder regions of CSPs have been explored systematically to understand the pleiotropic role of the cold shock family of proteins.
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| 34. |
- Chen, Lan, et al.
(author)
-
A modified ionization difference UV-vis method for fast quantitation of guaiacyl-type phenolic hydroxyl groups in lignin
- 2022
-
In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 201, s. 330-337
-
Journal article (peer-reviewed)abstract
- An ionization difference UV-Vis method (Delta epsilon-spectrum method) is the most potentially simple method for fast quantitation of phenolic hydroxyl groups (ph-OH) in lignin. However, the underestimated results were calculated from the conventional Delta epsilon-spectrum method using one- or two-point wavelengths measurement. In this study, a modified Delta epsilon-spectrum method using multi-point wavelengths measurement was developed and the negative absorbance was also considered. Four main typical lignin models, e.g. vanilla alcohol, 5-5 biphenyl, stilbenoid and vanillin, were applied as the guaiacyl-type (G-type) phenolic models for the determination of ph-OH by the modified Delta epsilon-spectrum method. The 2-methoxyethanol/water/acetic acid = 8/2/0.2 (V/V/V) was used as the acidic solvent system and the 2-methoxyethanol/0.2 M NaOH solution = 1/9 (V/V) was used as the alkaline solvent system. The ph-OH contents in the spruce milled wood lignin (SMWL) and the spruce Kraft lignin (SKL) were respectively quantified by the modified Delta epsilon-spectrum method as 1.078 and 4.348 mmol/g, which were comparable to the counterparts determined by P-31 Nuclear Magnetic Resonance Spectroscopy (P-31 NMR). The results revealed that the modified Delta epsilon-spectrum method can provide more accurate and reliable results compared to the conventional method.
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| 35. |
- Chen, Yihan, et al.
(author)
-
Characterization of the structure and analysis of the anti-oxidant effect of microalga Spirulina platensis polysaccharide on Caenorhabditis elegans mediated by modulating microRNAs and gut microbiota
- 2020
-
In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 163, s. 2295-2305
-
Journal article (peer-reviewed)abstract
- The antioxidant activity of Spirulina platensis polysaccharide (SPP) was investigated in Caenorhabditis elegans. Nuclearmagnetic resonance, Fourier-transform infrared, multi-angle laser light scattering, and GC-MS were used to identify the structural characteristics of SPP. It was composed of the -> 2)-alpha-L-Rhap-(1 ->, -> 4)-beta-D-Manp-(1 ->, -> 6)-beta-D-Glcp-(1 ->, -> 4)-beta-Xylp-(1 ->, -> 3)-beta-L-Araf-(1 ->, and -> 2)-beta-L-Fucp-(1 ->, respectively. The modulation of gut microbiota in C. elegans was determined using 16S rRNA gene high-throughput sequencing. The malondialdehyde (MDA) content was significantly decreased, while the total superoxide dismutase (T-SOD) and reactive oxygen species (ROS) levels were improved after SPP supplementation. The cellular mitochondrial content and apoptosis were significantly down-regulated. The obvious increased levels of the DAF-16 and SKN-1 mRNAs were observed in the SPP-treated group, while the levels of miR-48 and miR-51 were significantly reduced. Moreover, SPP administration significantly increased the abundance of Flavobacterium, Achromobacter, Empedobacter, Anaerolinea, and Pseudoalteromonas of the intestinal flora. Based on these results, S. platensis polysaccharides may be used as a functional food to ameliorate diseases related to oxidative stress.
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| 36. |
- Cho, Sung-Woo, et al.
(author)
-
Injection-molded nanocomposites and materials based on wheat gluten
- 2011
-
In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 48:1, s. 146-152
-
Journal article (peer-reviewed)abstract
- This is, to our knowledge, the first study of the injection molding of materials where wheat gluten (WG) is the main component. In addition to a plasticizer (glycerol), 5 wt.% natural montmorillonite clay was added. X-ray indicated intercalated clay and transmission electron microscopy indicated locally good clay platelet dispersion. Prior to feeding into the injection molder, the material was first compression molded into plates and pelletized. The filling of the circular mold via the central gate was characterized by a divergent flow yielding, in general, a stronger and stiffer material in the circumferential direction. It was observed that 20–30 wt.% glycerol yielded the best combination of processability and mechanical properties. The clay yielded improved processability, plate homogeneity and tensile stiffness. IR spectroscopy and protein solubility indicated that the injection molding process yielded a highly aggregated structure. The overall conclusion was that injection molding is a very promising method for producing WG objects.
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| 37. |
- Chong, Sun-Li, et al.
(author)
-
Glucuronic acid in Arabidopsis thaliana xylans carries a novel pentose substituent
- 2015
-
In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 79, s. 807-812
-
Journal article (peer-reviewed)abstract
- Glucuronic acids in Arabidopsis thaliana xylans exist in 4-O-methylated (MeGlcA) and non-methylated (GlcA) forms at a ratio of about 3:2. The matrix-assisted laser desorption/ionization mass spectrometry analysis of the endoxylanase liberated acidic oligosaccharides from the Arabidopsis inflorescence stem showed that two peaks with GlcA (GlcA-Xyl(4)Ac(1) and GlcA-Xyl(5)Ac(2)) had abnormally high intensities, as well as different tandem mass spectra, than their 4-O-methylated counterparts. These peaks were interestingly enriched in the xylan biosynthesis mutant irx7 and irx9-1. Multi-stages fragmentation analysis using negative ion electrospray-ion trap mass spectrometry indicated that this GlcA was further carrying a pentose residue in the glucuronoxylan-derived oligosaccharide from irx9-1. The structure was also identified in Arabidopsis wild type. The results prove evidence of a new pentose substitution on the GlcA residue of Arabidopsis GX, which is likely present in the primary walls. (C) 2015 Elsevier B.V. All rights reserved.
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| 38. |
- Chudasama, Nishith A., et al.
(author)
-
Preparation of seaweed polysaccharide based hydrophobic composite membranes for the separation of oil/water emulsion and protein
- 2022
-
In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 199, s. 36-41
-
Journal article (peer-reviewed)abstract
- Agarose is a seaweed-based polysaccharide and is widely used for the separation of nucleic acids in molecular biology. Cross-linked agarose beads are also used as solid-phase matrices in size exclusion chromatography for the separation of proteins. To find the application of agarose for the separation of oil/water emulsion and protein, herein hydrophobic derivative of the seaweed biopolymer [M-W (1.27 +/- 0.17) x 10(-5) g/mol; sulphate content (0.29 +/- 0.09) %, gel strength (2242 +/- 21) g/cm(2)] is prepared by reacting the biopolymer with stearic acid and was used to prepare a composite membrane on polyester fabric. The oil and BSA rejection performance of the composite membrane was greater than 98%. The rejection rate increased with the increase in polymer content in the respective membranes for both oil/water and protein separation. The composite membrane showed a stable oil/water emulsion and protein separation performance over a period of six hours. Due to the biodegradable nature of the major components of the membrane, it has the potential for industrial applications.
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| 39. |
- Criveanu, Dan, et al.
(author)
-
Identification of a new Kir6 potassium channel and comparison of properties of Kir6 subtypes by structural modelling and molecular dynamics
- 2023
-
In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 247
-
Journal article (peer-reviewed)abstract
- ATP-sensitive potassium ion channels (KATP) are transmembrane proteins that modulate insulin release and muscle contraction. KATP channels are composed of two types of subunit, Kir6 and SUR, which exist in two and three isoforms respectively with different tissue distribution. In this work, we identify a previously undescribed ancestral vertebrate gene encoding a Kir6-related protein that we have named Kir6.3, which may not have a SUR binding partner, unlike the other two Kir6 proteins. Whereas Kir6.3 was lost in amniotes including mammals, it is still present in several early-diverging vertebrate lineages such as frogs, coelacanth, and rayfinned fishes. Molecular dynamics (MD) simulations using homology models of Kir6.1, Kir6.2, and Kir6.3 from the coelacanth Latimeria chalumnae showed that the three proteins exhibit subtle differences in their dynamics. Steered MD simulations of Kir6-SUR pairs suggest that Kir6.3 has a lower binding affinity for the SUR proteins than either Kir6.1 or Kir6.2. As we found no additional SUR gene in the genomes of the species that have Kir6.3, it most likely forms a lone tetramer. These findings invite studies of the tissue distribution of Kir6.3 in relation to the other Kir6 as well as SUR proteins to determine the functional roles of Kir6.3.
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| 40. |
- Das, Atanu Kumar, et al.
(author)
-
Lignin - A green material for antibacterial application : A review
- 2024
-
In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 261:2
-
Journal article (peer-reviewed)abstract
- Lignin’s antibacterial properties have become increasingly relevant due to the rise of microbial infectious diseases and antibiotic resistance. Lignin is capable of interacting electrostatically with bacteria and contains polyphenols that cause damage to their cell walls. These features make lignin a desirable material to exhibit antibacterial behavior. Therefore, lignin in antibacterial applications offers a novel approach to address the growing need for sustainable and effective antibacterial materials. Recent research has explored the incorporation of lignin in various biomedical applications, such as wound dressings, implants, and drug delivery systems, highlighting their potential as a sustainable alternative to synthetic antibacterial agents. Furthermore, the development of lignin -based nanomaterials with enhanced antimicrobial activity is an active area of research that holds great promise for the future. In this review, we have provided a summary of how lignin can be incorporated into different forms, such as composite and non -composite synthesis of antibacterial agents and their performances. The challenges and future considerations are also discussed in this review article.
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| 41. |
- Das, Atanu Kumar
(author)
-
Lignin - A green material for antibacterial application — A review
- 2024
-
In: International Journal of Biological Macromolecules. - 0141-8130 .- 1879-0003. ; 261
-
Research review (peer-reviewed)abstract
- Lignin's antibacterial properties have become increasingly relevant due to the rise of microbial infectious diseases and antibiotic resistance. Lignin is capable of interacting electrostatically with bacteria and contains polyphenols that cause damage to their cell walls. These features make lignin a desirable material to exhibit antibacterial behavior. Therefore, lignin in antibacterial applications offers a novel approach to address the growing need for sustainable and effective antibacterial materials. Recent research has explored the incorporation of lignin in various biomedical applications, such as wound dressings, implants, and drug delivery systems, highlighting their potential as a sustainable alternative to synthetic antibacterial agents. Furthermore, the development of lignin-based nanomaterials with enhanced antimicrobial activity is an active area of research that holds great promise for the future. In this review, we have provided a summary of how lignin can be incorporated into different forms, such as composite and non-composite synthesis of antibacterial agents and their performances. The challenges and future considerations are also discussed in this review article.
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| 42. |
- De Cristofaro, Giuseppa Anna, et al.
(author)
-
Interface interactions driven antioxidant properties in olive leaf extract/cellulose nanocrystals/poly(butylene adipate-co-terephthalate) biomaterials
- 2024
-
In: International Journal of Biological Macromolecules. - 0141-8130 .- 1879-0003. ; 272
-
Journal article (peer-reviewed)abstract
- Functional packaging represents a new frontier for research on food packaging materials. In this context, adding antioxidant properties to packaging films is of interest. In this study, poly(butylene adipate-co-terephthalate) (PBAT) and olive leaf extract (OLE) have been melt-compounded to obtain novel biomaterials suitable for applications which would benefit from the antioxidant activity. The effect of cellulose nanocrystals (CNC) on the PBAT/OLE system was investigated, considering the interface interactions between PBAT/OLE and OLE/CNC. The biomaterials' physical and antioxidant properties were characterized. Morphological analysis corroborates the full miscibility between OLE and PBAT and that OLE favours CNC dispersion into the polymer matrix. Tensile tests show a stable plasticizer effect of OLE for a month in line with good interface PBAT/OLE interactions. Simulant food tests indicate a delay of OLE release from the 20 wt% OLE-based materials. Antioxidant activity tests prove the antioxidant effect of OLE depending on the released polyphenols, prolonged in the system at 20 wt% of OLE. Fluorescence spectroscopy demonstrates the nature of the non-covalent PBAT/OLE interphase interactions in π-π stacking bonds. The presence of CNC in the biomaterials leads to strong hydrogen bonding interactions between CNC and OLE, accelerating OLE released from the PBAT matrix.
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| 43. |
- de Jesus, Liana Inara, et al.
(author)
-
Chemical characterization and wound healing property of a beta-D-glucan from edible mushroom Piptoporus betulinus
- 2018
-
In: International Journal of Biological Macromolecules. - : Elsevier. - 0141-8130 .- 1879-0003. ; 117, s. 1361-1366
-
Journal article (peer-reviewed)abstract
- A water-soluble beta-D-glucan was obtained from fruiting bodies of Piptoporus betulinus, by hot aqueous extraction followed by freeze-thawing procedure and dialysis. Its molar mass distribution and conformational behavior in solution was assessed by size-exclusion chromatography coupled with multiangle laser light scattering, showing a polysaccharide with an average molecular weight of 2.5 x 10(5) Da with a random coil conformation for molecular weights below 1 x 10(6) Da. Typical signals of beta-(1 -> 3)-linkages were observed in NMR spectrum (delta 102.7/4.76; 102.8/4.74; 102.9/4.52; and delta 85.1/3.78; 85.0/3.77) and also signals of O-6 substitution at delta 69.2/4.22 and 69.2/3.87. The analysis of partially O-methylated alditol acetates corroborates the NMR results, indicating the presence of a beta-D-glucan with a main chain (1 -> 3)-linked, substituted at O-6 by single-units of glucose. The beta-D-glucan showed no toxicity on human colon carcinoma cell line (Caco-2) up to 1000 mu g mL(-1) and promoted cell migration on in vitro scratch assay, demonstrating a potential wound healing capacity.
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| 44. |
- Delogu, Giovanna Lucia, et al.
(author)
-
A new biological prospective for the 2-phenylbenzofurans as inhibitors of α-glucosidase and of the islet amyloid polypeptide formation
- 2021
-
In: International Journal of Biological Macromolecules. - : Elsevier. - 0141-8130 .- 1879-0003. ; 169, s. 428-435
-
Journal article (peer-reviewed)abstract
- In this study, we have investigated a series of hydroxylated 2-phenylbenzofurans compounds for their inhibitory activity against α-amylase and α-glucosidase activity.Inhibitors of carbohydrate degrading enzymes seem to have an important role as antidiabetic drugs.Diabetes mellitus is a wide-spread metabolic disease characterized by elevated levels of blood glucose. The most common is type 2 diabetes, which can lead to severe complications. Since the aggregates of islet amyloid polypeptide (IAPP) are common in diabetic patients, the effect of compounds to inhibit amyloid fibril formation was also determined.All the compounds assayed showed to be more active against α-glucosidase. Compound 16 showed the lowest IC50 value of the series, and it is found to be 167 times more active than acarbose, the reference compound. The enzymatic activity assays showed that compound 16 acts as a mixed-type inhibitor of α-glucosidase. Furthermore, compound 16 displayed effective inhibition of IAPP aggregation and it manifested no significant cytotoxicity.To predict the binding of compound 16 to IAPP and α-glucosidase protein complexes, molecular docking studies were performed.Altogether, our results support that the 2-phenylbenzofuran derivatives could represent a promising candidate for developing molecules able to modulate multiple targets involved in diabetes mellitus disorder.
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| 45. |
- Deralia, Parveen Kumar, 1985, et al.
(author)
-
Hydrophobization of arabinoxylan with n-butyl glycidyl ether yields stretchable thermoplastic materials
- 2021
-
In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 188, s. 491-500
-
Journal article (peer-reviewed)abstract
- Hemicelluloses are regarded as one of the first candidates for the development of value-added materials due to their renewability, abundance, and functionality. However, because most hemicelluloses are brittle, they can only be processed as a solution and cannot be processed using industrial melt-based polymer processing techniques. In this study, arabinoxylan (AX) was hydrophobized by incorporating butyl glycidyl ether (BuGE) into the hydroxyl groups through the opening of the BuGE epoxide ring, yielding alkoxy alcohols with terminal ethers. The formed BuGE derivatives were melt processable and can be manufactured into stretchable thermoplastic films through compression molding, which has never been done before with hemicellulose modified in a single step. The structural and thermomechanical properties of the one-step synthesis approach were compared to those of a two-step synthesis with a pre-activation step to demonstrate its robustness. The strain at break for the one-step synthesized AX thermoplastic with 3 mol of BuGE is ≈200%. These findings suggest that thermoplastic polymers can be composited with hemicelluloses or that thermoplastic polymers made entirely of hemicelluloses can be designed as packaging and stretchable electronics supports.
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| 46. |
- Deyev, Sergey M., et al.
(author)
-
Effect of a radiolabel biochemical nature on tumor-targeting properties of EpCAM-binding engineered scaffold protein DARPin Ec1
- 2020
-
In: International Journal of Biological Macromolecules. - : ELSEVIER. - 0141-8130 .- 1879-0003. ; 145, s. 216-225
-
Journal article (peer-reviewed)abstract
- Radionuclide-based imaging of molecular therapeutic targets might facilitate stratifying patients for specific biotherapeutics. New type of imaging probes, based on designed ankyrin repeat proteins (DARPins), have demonstrated excellent contrast of imaging of human epidermal growth factor type 2 (HER2) expression in preclinical models. We hypothesized that labeling approaches, which result in lipophilic radiometabolites (non-residualizing labels), would provide the best imaging contrast for DARPins that internalize slowly after binding to cancer cells. The hypothesis was tested using DARPin Ec1 that binds to epithelial cell adhesion molecule (EpCAM). EpCAM is a promising therapeutic target. Ec1 was labeled with I-125 using two methods to obtain the non-residualizing labels, while residualizing labels were obtained by labeling it with Tc-99m. All labeled Ec1 variants preserved target specificity and picomolar binding affinity to EpCAM-expressing pancreatic adenocarcinoma BxPC-3 cells. In murine models, all the variants provided similar tumor uptake. However, I-125-PIB-H-6-Ec1 had noticeably lower retention in normal tissues, which provided appreciably higher tumor-to-organ ratios. Furthermore, I-125-PIB-H-6-Ec1 demonstrated the highest imaging contrast in preclinical models than any other EpCAM-imaging agent tested so far. In conclusion, DARPin Ec1 in combination with a non-residualizing label is a promising probe for imaging EpCAM expression a few hours after injection.
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| 47. |
- Dodda, Jagan Mohan, et al.
(author)
-
Bioresorbable films of polycaprolactone blended with poly(lactic acid) or poly(lactic-co-glycolic acid)
- 2023
-
In: International Journal of Biological Macromolecules. - : Elsevier. - 0141-8130 .- 1879-0003. ; 248
-
Journal article (peer-reviewed)abstract
- Recent complications on the use of polypropylene meshes for hernia repair has led to the development of meshes or films, which were based on resorbable polymers such as polycaprolactone (PCL), polylactic acid (PLA) and poly(lactic-co-glycolic acid) (PLGA). These materials are able to create suitable bioactive environment for the growth and development of cells. In this research, we mainly focused on the relations among structure, mechanical performance and biocompatiblity of PCL/PLA and PCL/PLGA and blends prepared by solution casting. The films were characterized regarding the chemical structure, morphology, physicochemical properties, cytotoxicity, biocompatibility and cell growth. All the films showed high tensile strength ranging from 9.5 to 11.8 MPa. SAXS showed that the lamellar stack structure typical for PCL was present even in the blend films while the morphological parameters of the stacks varied slightly with the content of PLGA or PLA in the blends. WAXS indicated preferential orientation of crystallites (and thus, also the lamellar stacks) in the blend films. In vitro studies revealed that PCL/PLGA films displayed better cell adhesion, spreading and proliferation than PCL/PLA and PCL films. Further the effect of blending on the degradation was investigated, to understand the significant variable within the process that could provide further control of cell adhesion. The results showed that the investigated blend films are promising materials for biomedical applications.
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| 48. |
- Dong, Zhiyun, et al.
(author)
-
Silk fibroin hydrogels induced and reinforced by acidic calcium phosphate : A simple way of producing bioactive and drug-loadable composites for biomedical applications
- 2021
-
In: International Journal of Biological Macromolecules. - : Elsevier. - 0141-8130 .- 1879-0003. ; 193, s. 433-440
-
Journal article (peer-reviewed)abstract
- Silk fibroin (SF) hydrogels have attracted extensive interest in biomedical applications due to their biocompatibility and wide availability. However, their generally poor mechanical properties limit their utility. Here, injectable, ready-to-use SF-based composites, simultaneously induced and reinforced by acidic calcium phosphates, were prepared via a dual-paste system requiring no complex chemical/physical treatment. The composite was formed by mixing a monocalcium phosphate monohydrate paste with a β-tricalcium phosphate/SF paste. The conformational transition of SF in an acidic environment forms continuous networks, and the acidic calcium phosphate, brushite and monetite, formed simultaneously in the networks during mixing. The composites displayed a partly elastomeric compression behavior, with mechanical properties increasing with an increasing calcium phosphate and β-sheet content at the lower calcium phosphate contents evaluated (22.2–36.4 wt%). While the stiffness was still relatively low, the materials presented a high elasticity and ductility, and no failure at stresses in the range of failure stresses of trabecular bone. Furthermore, the calcium phosphate confers bioactivity to the material, and the composites with a promising in vitro cell response also showed potential as drug vehicles, using vancomycin as a model drug. These dual-paste systems exhibit potential utility in biomedical applications, such as bone void fillers and drug vehicles.
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| 49. |
- Duraisamy, Murugesan, et al.
(author)
-
Novel ruthenium-doped vanadium carbide/polymeric nanohybrid sensor for acetaminophen drug detection in human blood
- 2023
-
In: International Journal of Biological Macromolecules. - 0141-8130 .- 1879-0003. ; 244
-
Journal article (peer-reviewed)abstract
- The use of advanced electroactive catalysts enhances the performance of electrochemical biosensors in real-time biomonitoring and has received much attention owing to its excellent physicochemical and electrochemical possessions. In this work, a novel biosensor was developed based on the electrocatalytic activity of functionalized vanadium carbide (VC) material, including VC@ruthenium (Ru), VC@Ru-polyaniline nanoparticles (VC@Ru-PANI-NPs) as non-enzymatic nanocarriers for the fabrication of modified screen-printed electrode (SPE) to detect acetaminophen in human blood. As-prepared materials were characterized using SEM, TEM, XRD, and XPS techniques. Biosensing was carried out using cyclic voltammetry and differential pulse voltammetry techniques and has revealed imperative electrocatalytic activity. A quasi-reversible redox method of the over-potential of acetaminophen increased considerably compared with that at the modified electrode and the bare SPE. The excellent electrocatalytic behaviour of VC@Ru-PANI-NPs/SPE is attributed to its distinctive chemical and physical properties, including rapid electron transfer, striking ᴫ-ᴫ interface, and strong adsorptive capability. This electrochemical biosensor exhibits a detection limit of 0.024 μM, in a linear range of 0.1–382.72 μM with a reproducibility of 2.45 % relative standard deviation, and a good recovery from 96.69 % to 105.59 %, the acquired results ensure a better performance compared with previous reports. The enriched electrocatalytic activity of this developed biosensor is mainly credited to its high surface area, better electrical conductivity, synergistic effect, and abundant electroactive sites. The real-world utility of the VC@Ru-PANI-NPs/SPE-based sensor was ensured via the investigation of biomonitoring of acetaminophen in human blood samples with satisfactory recoveries.
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| 50. |
- Ehman, N. V., et al.
(author)
-
Influence of initial chemical composition and characteristics of pulps on the production and properties of lignocellulosic nanofibers
- 2020
-
In: International Journal of Biological Macromolecules. - : Elsevier B.V.. - 0141-8130 .- 1879-0003. ; 143, s. 453-461
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Journal article (peer-reviewed)abstract
- This work aimed to study the influence of the initial chemical composition (glucans, lignin, xylan, and mannans), intrinsic viscosity, and carboxylate groups of pulps on the production process and final properties of lignocellulosic nanofibers (LCNF). Pulps of pine sawdust, eucalyptus sawdust, and sugarcane bagasse subjected to conventional pulping and highly oxidized processes were the starting materials. The LCNF were obtained by TEMPO mediated oxidation and mechanical fibrillation with a colloidal grinder. The nanofibrillation degree, chemical charge content, rheology, laser profilometry, cristallinity and atomic force microscopy were used to characterize the LCNF. The carboxylate groups, hemicelluloses and lignin of the initial pulps were important factors that affected the production process of LCNF. The results revealed that intrinsic viscosity and carboxylate groups of the initial pulps affected LCNF production process, whereas lignin and hemicelluloses influenced the viscosity of LCNF aqueous suspensions, the roughness of LCNF films, and the carboxylate groups content of LCNF
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