Degradation properties of Chitosan Microspheres/Poly(L-lactic acid) Composite in vitro and in vivo Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-21 Zhenzhao Guo, Dongying Bo, Yuan He, Xueshi Luo, Hong Li
Poly(L-lactic acid) (PLLA) is a popular biodegradable polymer, but the accumulated acid production by degradation is a bottleneck for its extended utilization. In this study, chitosan microspheres (CSMs) were introduced into PLLA porous matrices to manipulate the acid microclimate from PLLA degradation. In vitro and in vivo degradation were, respectively, performed in PBS and implanted into rat’s subcutaneous. The results indicated that pH of CSMs/PLLA composites remained stable of around 7.50 in vitro until six weeks. With the increasing of CSMs, mass loss, water absorption of the composites increased, while Mv of PLLA decreased during in vitro test. Furthermore, CSMs/PLLA composites degradation in vivo could be speeded by the introduction of CSMs via obvious morphological destroy under H&E staining observation. These results indicated that incorporation of CSMs not only buffered the acidic microclimate but also improved the degradation of PLLA. The tunable degradation behavior and moderate degradation microclimate of CSMs/PLLA composites developed in the study would provide benefits for its biomedical application.
Chitosan derivative-based self-healable hydrogels with enhanced mechanical properties by high-density dynamic ionic interactions Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-21 Ningxiao Yuan, Lu Xu, Bo Xu, Jianhao Zhao, Jianhua Rong
Chitosan derivative-based self-healable hydrogels with enhanced mechanical properties are reported, which were prepared by polymerization of acrylic acid (AAc) in 2-hydroxypropyltrimethyl ammonium chloride chitosan (HACC) solution. The PAAc/HACC hydrogels exhibit tensile fracture stress as high as 3.31 MPa and a Young's modulus of 2.53 MPa. They can maintain their original shape after 30 repeated compression cycles under various strain conditions, with a compression stress of more than 60 MPa at 99% strain. The damaged PAAc/HACC hydrogels can heal together in the presence of a NaCl salt solution with a self-healing efficiency of up to 61%. In addition, the PAAc/HACC hydrogels have high ionic conductivity and can serve as electrolytes for supercapacitors. The analysis suggests that all these good properties of the PAAc/HACC hydrogels mainly result from their high-density dynamic ionic interactions structure.
Gel properties and interactions of Mesona blumes polysaccharide-soy protein isolates mixed gel: The effect of salt addition Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-21 Wenjie Wang, Mingyue Shen, Sucheng Liu, Lian Jiang, Qianqian Song, Jianhua Xie
Effect of different salt ions on the gel properties and microstructure of Mesona blumes polysaccharide (MBP)-soy protein isolates (SPI) mixed gels were investigated. Sodium and calcium ions were chosen to explore their effects on the rheological behavior and gel properties of MBP-SPI mixed gels were evaluated by using rheological, X-ray diffraction, protein solubility determination, and microstructure analysis. Results showed that the addition of salt ions change the crystalline state of gels system, the crystal of gel was enhanced at low ion concentrations (0.005-0.01 M). The two peaks of gel characteristic at 8.9° and 19.9° almost disappeared at high salt ions concentrations (0.015-0.02 M), and new crystallization peaks appeared at around 30° and 45°. The elasticity, viscosity, gel strength, water holding capacity, and thermal stability of gel were increased at low ion concentration. Results showed that the main interactions which promoted gel formation and maintain the three-dimensional structure of the gel were electrostatic interactions, hydrophobic interactions, and disulfide interactions.
Interactions between pectin and cellulose in primary plant cell walls Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-20 Suzanne E. Broxterman, Henk A. Schols
To understand the architecture of the plant cell wall, it is of importance to understand both structural characteristics of cell wall polysaccharides and interactions between these polysaccharides. Interactions between polysaccharides were studied in the residue after water and chelating agent extraction by sequential extractions with H2O and alkali. The 6 M alkali residue still represented 31%, 11% and 5% of all GalA present in carrot, tomato and strawberry, respectively, and these pectin populations were assumed to strongly interact with cellulose. Digestion of the carrot 6 M alkali residue by glucanases released ∼27% of the 6 M residue, mainly representing pectin. In tomato and strawberry alkali residues, glucanases were not able to release pectin populations. The ability of glucanases to release pectin populations suggests that the carrot cell wall contains unique, covalent interactions between pectin and cellulose.
Chitosan-polytetrafluoroethylene composite membranes for separation of methanol and toluene by pervaporation Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-20 Siddhartha Moulik, Bukke Vani, S.S. Chandrasekhar, S. Sridhar
Present work reports the synthesis of a novel Chitosan-Polytetrafluoroethylene composite membrane with solvent resistant property for efficient separation of methanol/toluene mixture by pervaporation. The composite was crossed with tetraethyl orthosilicate (TEOS) to prevent or reduce membrane swelling and improve the separation factor. The synthesized membranes were characterized by SEM, FTIR and DSC analysis. Molecular dynamics (MD) simulation and computational fluid dynamics were coupled to predict the structural and diffusive properties besides concentration profile inside the membrane. Diffusion coefficients of methanol and toluene were found to be 1.7 × 10−9 and 1.8 × 10−12 m2/s, respectively. The effect of crosslinking on process parameters such as flux and separation factor was analyzed. The study confirmed that increasing TEOS concentration reduced the methanol flux but enhanced separation factor with respect to this alcohol. The membranes exhibited a flux of 0.13 kg/m2h and separation factor of 58.4 for azeotropic feed composition of 68 wt% methanol.
A synbiotic multiparticulate microcapsule for enhancing inulin intestinal release and Bifidobacterium gastro-intestinal survivability Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-20 Bahgat Fayed, Amira Abood, Hoda S. El-Sayed, Amal M. Hashem, Nayra SH. Mehanna
A novel synbiotic multiparticulate microparticle was produced in the current study to expand the synbiotic industrial applications. Initially, the inulin was fabricated into PLGA nanoparticles. After the inulin entrapment efficiency was boosted to reach 92.9 ± 8.4% by adjusting the formulation parameters, the developed particles were characterized by different techniques such as particle size analyzer, TEM, and TLC. The obtained data showed that the particle size was 115.8 ± 82.7 nm, the particles had smooth surface and round shape, and the fabrication procedure did not affect the integrity of the inulin. Later, the inulin loaded nanoparticles together with selected Bifidobacterium species were double coated with gum arabic and alginate. The maximum survivability of the encapsulated Bifidobacterium in the simulated gastric solution reached 88.29% of the initial population, which was significantly higher than the survivability of the free bacteria. Finally, the inulin release from the multiparticulate microparticles was studied and found to be sustained over three days.
Effects of carboxyl and aldehyde groups on the antibacterial activity of oxidized amylose Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-20 Yaxin Zi, Mingjin Zhu, Xinying Li, Yongbin Xu, Hao Wei, Defu Li, Changdao Mu
Dialdehyde-amyloses, dicarboxyl-amyloses and dialdehyde-carboxyl-amyloses with different oxidation levels were prepared and used to study the effects of aldehyde and carboxyl groups on the antibacterial activity of oxidized amyloses. The results showed that dicarboxyl-amyloses presented antibacterial activity through acidic pH effect produced by carboxyl groups, which was easily reduced or eliminated by adjusting pH. Dialdehyde-amyloses possessed a broad-spectrum antibacterial activity owning to the reactivity of aldehyde groups rather than acidic pH effect. Aldehyde would irreversibly damage bacterial cell wall and cytoplasmic membrane, resulting in decay and death of bacterial cells. It is interesting that the antibacterial properties of dialdehyde-carboxyl-amyloses were improved to some extent compared to dialdehyde-amyloses. The improvement of antibacterial effect of dialdehyde-carboxyl-amyloses may be due to the increasing dispersibility endowed by carboxyl groups, which could effectively enhance the interaction between dialdehyde-carboxyl-amyloses and bacteria. As a result, carboxyl group could act as a promising synergistic group against bacteria with aldehyde group.
Radical scavenging activity of sulfated Bupleurum chinense polysaccharides and their effects against oxidative stress-induced senescence Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-19 Haibin Tong, Xiaoli Zheng, Jianxi Song, Jian Liu, Ting Ren, Xu Zhang, Luqi Huang, Mingjiang Wu
In this study, BCPS-1, a polysaccharide previously isolated and characterized from Bupleurum chinense was chemically modified to yield two sulfated derivatives, which we designated as S-BCP1-4 and S-BCP1-8. The physicochemical properties of these sulfated derivatives were then determined by high performance liquid chromatography (HPLC), Fourier transform infrared spectrometry (FT-IR), and gas chromatography (GC), and then compared with those of BCPS-1. Furthermore, the antioxidant activities of all three polysaccharides were also evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical assay, superoxide radical assay and hydroxyl radical assay, while their effects against H2O2-induced cellular senescence were determined using senescence-associated β-galactosidase (SA-β-gal) staining, cell cycle assay and immunoblotting in H2O2-induced mouse lung endothelial cells (MLECs). Compared to BCPS-1, S-BCP1-4 and S-BCP1-8 exhibited remarkable antioxidant effect, and in a concentration-dependent manner. They also provided stronger protection against H2O2-induced cellular senescence in MLECs. These results indicated that the sulfate group in the modified B. chinense polysaccharides might play an important role in radical scavenging and resistance to H2O2-induced senescence. These sulfated polysaccharides could be considered as novel pharmaceutical products with potential antioxidant and anti-senescence effects.
Spatial Structures of Rhamnogalacturonan I in Gel and Colloidal Solution Identified by 1D and 2D-FTIR Spectroscopy Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-19 Olga N. Makshakova, Dzhigangir A. Faizullin, Polina V. Mikshina, Tatyana A. Gorshkova, Yuriy F. Zuev
Preparation of nanocellulose from Imperata Brasiliensis grass using Taguchi Method Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-19 Kelly Cristina Coelho de Carvalho Benini, Herman Jacobus Cornelis Voorwald, Maria Odila Hilário Cioffi, Mirabel Cerqueira Rezende, Valdeir Arantes
Cellulose nanoparticles (CNs) were prepared by acid hydrolysis of the cellulose pulp extracted from the Brazilian satintail (Imperata Brasiliensis) plant using a conventional and a total chlorine free method. Initially, a statistical design of experiment was carried out using Taguchi orthogonal array to study the hydrolysis parameters, and the main properties (crystallinity, thermal stability, morphology, and sizes) of the nanocellulose. X-ray diffraction (XRD), fourier-transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FE-SEM), dynamic light scattering (DLS), zeta potential and thermogravimetric analysis (TGA) were carried out to characterize the physical-chemical properties of the CNs obtained. Cellulose nanoparticles with diameter ranging from 10 to 60 nm and length between 150–250 nm were successfully obtained at sulfuric acid concentration of 64% (m/m), temperature 35 °C, reaction time 75 min, and a 1:20 (g/mL) pulp-to-solution ratio. Under this condition, the Imperata Brasiliensis CNs showed good stability in suspension, crystallinity index of 65%, and a cellulose degradation temperature of about 117 °C. Considering that these properties are similar to those of nanocelluloses from other lignocellulosics feedstocks, Imperata grass seems also to be a suitable source for nanocellulose production.
Characterization and microbiological evaluation of chitosan-alginate microspheres for cefixime vaginal administration Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-19 F. Maestrelli, M. Jug, M. Cirri, I. Kosalec, P. Mura
Chitosan-alginate microspheres (MS) were developed for cefixime vaginal administration, to overcome problems associated with its oral administration. The effect of increasing drug-loading amount, by keeping the chitosan-alginate content constant, was investigated. Mucoadhesion studies indicated that all formulations assured in situ permanence longer than 2 h. Entrapment efficiency increased with drug loading concentration in the starting solution, reaching a plateau at 30 mg/mL indicative of the achievement of an optimal drug-to-polymer ratio. MS swelling properties increased with the entrapped drug amount, and, interestingly, water-uptake reached its maximum value at the same drug loading concentration of 30 mg/mL. The relationship found between MS water-uptake and drug release rate confirmed MS prepared with 30 mg/mL cefixime as the best formulation. Microbiological studies showed a relation between cefixime release rate from MS and Escherichia coli viability reduction, definitely indicating the selected MS formulation as the best for an effective local treatment of urogenital infections.
Nanofibers of cellulose bagasse from Agave tequilana Weber var. azul by electrospinning: preparation and characterization Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-19 Miguel Ángel Robles-García, Carmen Lizette Del-Toro-Sánchez, Enrique Márquez-Ríos, Arturo Barrera-Rodríguez, Jacobo Aguilar, A. Aguilar José, Francisco Javier Reynoso-Marín, I. Ceja, R. Dórame-Miranda, Francisco Rodríguez-Félix
In this study, cellulose of bagasse from Agave tequilana Weber var. azul was extracted to elaborate nanofibers by the electrospinning technique. Fiber characterization was performed using Transmission Electron Microscopy (TEM), x-ray, Fournier Transform-InfraRed (FT-IR) spectroscopy, and thermal analysis by Differential Scanning Calorimetry-Thermogravimetric Analysis (DSC-TGA). Different diameters (ranging from 54.57 ± 0.02 to 171 ± 0.01 nm) of nanofibers were obtained. Cellulose nanofibers were analyzed by means of x-ray diffraction, where we observed a total loss of crystallinity in comparison with the cellulose, while FT-IR spectroscopy revealed that the hemicellulose and lignin present in the agave bagasse were removed. Thermal analysis showed that nanofibers exhibit enhanced thermal properties, and the zeta potential value (-32.5 mV) demonstrated moderate stability in the sample. In conclusion, the nanofibers obtained provide other alternatives-of-use for this agro-industrial residue and could have potential in various industrial applications, among these encapsulation of bioactive compounds and reinforcing material, to mention a few.
Physical and Chemical Properties, Percutaneous Absorption-promoting Effects of Exopolysaccharide Produced by Bacillus atrophaeus WYZ Strain Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-19 Wenjing Zhu, Yuzhen Wang, Fang Yan, Ruiteng Song, Zhijian Li, Yiqing Li, Bo Song
A high yield of exopolysaccharides bacteria isolated from mangrove system was identified as Bacillus atrophaeus by 16S rDNA and named as WYZ strain. An exopolysaccharide (BPS) was obtained from this strain after purification with a yield of about 0.58 g/L. Then some physical and chemical properties of BPS, such as weight average molecular weight (Mw), monosaccharide composition, intrinsic viscosity and water retention capacity were studied. The microstructure (SEM) showed that BPS was porous wound three-dimensional spider web structure. Using BPS as transdermal absorption enhancer, and lidocaine as a test drug, in vitro and local anesthesia in live animals experiments were conducted to explore that the BPS promote lidocaine transdermal absorption and mechanism. In conclusion, the BPS had good water retention capacity and transdermal absorption promoting effect, all of these indicated that BPS has great potential in the field of biomaterials.
Role of process variables on the formation and in vitro digestion of gellan gels Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-19 Tatiana Porto Santos, Rosiane Lopes Cunha
Evaluation of magnetic nanoparticles influence on hyaluronic acid production from Streptococcus equi Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-19 Yasser A. Attia, Mohamed I. Kobeasy, Mohamed Samer
This work aims at developing a novel hyaluronic acid (HA) production method using magnetic nanoparticles (NPs). In a separate process, HA was produced with the addition of the amino acids (AA) as bio-additives. Regarding the NPs additives, the results showed that the highest dry weight of the produced HA was 0.264 g/l with the addition of 20 mg/l of Fe3O4 NPs. Concerning the AA additives, the results showed that the highest dry weight of the produced HA was 0.079 g/l with the addition of 0.26 g/l of glutamic acid (GA) compared to the control produced 0.065 g/l. These results led to further develop a novel HA production method which is preparing the Fe3O4 NPs using GA as stabilizer, where the results showed that dry weight of the produced HA was 0.435 g/l with the addition of 20 mg/l of Fe3O4-GA NPs.
Gradual Degradation of Fucoidan from Fucus vesiculosus and its Effect on Structure, Antioxidant and Antiproliferative Activities Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-19 Eric Lahrsen, Inga Liewert, Susanne Alban
The fucose-containing sulfated polysaccharides (syn. fucoidans) from brown algae exhibit a wide range of bioactivities and are therefore considered promising candidates for health-supporting and medical applications. During the past three decades, research on isolation, molecular characterization, and screening of in vitro and in vivo pharmacological activities has significantly increased. Until now, however, fucoidans are only used as ingredients in cosmetics and food supplements, especially due to the proclaimed antioxidant activities of fucoidan. One obstacle to medical applications is the usually high molecular mass of native fucoidans, as it is associated with unfavorable biopharmaceutical properties and possibly undesired effects. Therefore, it seems reasonable to develop fucoidan derivatives with reduced size. So far, in this study, fucoidan from Fucus vesiculosus was gradually degraded from Mw 38.2 down to 4.9 kDa without concomitant desulfation. Compared to hydrothermal treatment, the degradation with H2O2 showed to be more efficient and additionally eliminated the antioxidant and antiproliferative activities of the genuine fucoidan. This confirmed our previous hypothesis that rather co-extracted compounds like terpenoids and polyphenols than the fucoidan itself exhibit these effects.
Polyelectrolyte complex of Aloe vera, chitosan, and alginate produced fibroblast and lymphocyte viabilities and migration Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-19 Raquel Gallardo-Rivera, María de los Ángeles Aguilar-Santamaría, Phaedra Silva-Bermúdez, Julieta García-López, Alberto Tecante, Cristina Velasquillo, Angélica Román-Guerrero, César Pérez-Alonso, Humberto Vázquez-Torres, Keiko Shirai
Chitosan, sodium alginate and gel of Aloe vera (Aloe barbadensis Miller) were employed for the preparation of polyelectrolyte complexes at pH 4 and 6. FT-IR spectroscopy analysis showed evidence on complexes formation and incorporation of the Aloe vera gel. The ζ potential determination of the polyelectrolyte complexes revealed the presence of surface charges in the range of −20 to −24 mV, which results in stable systems. The dynamic moduli exhibited a high dependence on angular frequency, which is commonly found in solutions of macromolecules. The materials showed human fibroblast and lymphocyte viabilities up to 90% in agreement with null cytotoxicity. The polyelectrolyte complexes at pH 6 with Ca2+ were stable, showed high water absorption, satisfactory morphology, pore size and rigidity, characteristics that allowed significant human fibroblast migration in wound closure in vitro assays.
Cellulose and chitin composite materials from an ionic liquid and a green co-solvent Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-18 Yaqing Duan, Auriane Freyburger, Werner Kunz, Cordt Zollfrank
We report on a method for the preparation of cellulose/chitin composite materials from the ionic liquid 1-butyl-3-methylimidazolium acetate and γ-valerolactone as a biosourced sustainable co-solvent. Element analysis and attentuated total reflectance Fourier transform infrared spectroscopy show that the average degree of acetylation of chitin in the composite materials was around 82.5%. This indicates that chitin is not deacetylated to chitosan during the dissolution process. The X-ray diffraction results show that the degree of crystallinity of the composite materials increases from amorphous to 59% with increasing chitin concentration accompanied by a developing crystallite size up to 3 nm. Mechanical testing yielded a maximum tensile stress of 4.7 MPa, an elastic modulus of 27.4 MPa and a breaking elongation of 78.7% for the composites with 80 wt% chitin. In addition, water contact angle measurements indicated that the presence of chitin rendered the materials more hydrophobic.
An investigation on the effect of polyphenolic extracts of Nigella sativa seedcake on physicochemical properties of chitosan-based films Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-18 Deepak Kadam, Nirali Shah, Shanooba Palamthodi, S.S. Lele
Nigella sativa seedcake phenolic extract (NSE), as compared to tannic acid (TA), was evaluated for its effect on film-forming ability of chitosan. These films were evaluated for their tensile strength, elongation, water vapor permeability (WVP), type of bonding, color, surface morphology, polyphenol and in vitro antioxidant activity release profile. At 7.5% (v/v of film-forming solution), NSE led to 42% decrease in tensile strength but improved the elongation by 66%, contradicting the effect of TA in chitosan films. WVP and crystallinity decreased with increasing NSE concentration. Changes in absorbance intensity by FTIR indicated structural modification. The calorimetric analysis showed changes in melting point and degree of crystallinity due to NSE. The release of total polyphenols and subsequent antioxidant activity in the water, 50% ethanol, and 95% ethanol media indicated potential application in active-packaging. This study shall help valorization of N. sativa seedcake after oil extraction for packaging, pharmaceutical, and allied applications.
Design and preparation of metal-organic framework papers with enhanced mechanical properties and good antibacterial capacity Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-18 Liwei Qian, Dan Lei, Xiao Duan, Sufeng Zhang, Wenqi Song, Chen Hou, Ruihua Tang
In this study, a biodegradable paper-based composite with good mechanical and antibacterial properties was obtained by first reinforcing the cotton pulp-based paper with carboxylated cellulose nanofiber (CNF) via the Williamson reaction, followed by in situ generating zeolitic imidazolate framework-67 (ZIF-67) nanoparticles on the surface of the resulting cellulosic material. The mechanical properties and antibacterial activities of the resulting composite were investigated. The tensile testing demonstrated that the composites prepared with 2.5 wt% CNF exhibited outstanding mechanical performance under dry and wet conditions with the tensile strength values of 17.20 and 1.90 MPa, respectively, approximately 1.3 and 11 times higher compared to that of the original cellulose paper. Furthermore, the antibacterial experiments showed that the composites exhibited significant bacteriostasis, and the antibacterial properties increased significantly with increasing ZIF-67 loading in the composites. Consequently, this biodegradable composite could be potentially used in the field of medical and health security.
Cellulose I and II nanocrystals produced by sulfuric acid hydrolysis of Tetra pak cellulose I Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-18 Lida Xing, Jin Gu, Weiwei Zhang, Dengyun Tu, Chuanshuang Hu
Fungicidal effect of chitosan via inducing membrane disturbance against Ceratocystis fimbriata Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-18 Ke Xing, Yun Xing, Yuanfang Liu, Yu Zhang, Xiaoqiang Shen, Xiaoyan Li, Xiangmin Miao, Zhaozhong Feng, Xue Peng, Sheng Qin
Antimicrobial, Antioxidant, and Waterproof RTV Silicone-Ethyl Cellulose Composites Containing Clove Essential Oil Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-18 José A. Heredia-Guerrero, Luca Ceseracciu, Susana Guzman-Puyol, Uttam C. Paul, Alejandro Alfaro-Pulido, Chiara Grande, Luigi Vezzulli, Tiziano Bandiera, Rosalia Bertorelli, Debora Russo, Athanassia Athanassiou, Ilker S. Bayer
Ethyl cellulose (EC)/polydimethylsiloxane (PDMS) composite films were prepared at various concentrations of PDMS in the films (0, 5, 10, 15, and 20 wt.%). Morphological and chemical analysis by EDX-SEM and ATR-FTIR showed that EC-rich matrices and PDMS-rich particles were formed, with the two polymers interacting through H-bonds. The number and diameter of particles in the composite depended on the PDMS content and allowed a fine tuning of several properties such as opacity, hydrophobicity, water uptake, and water permeability. Relative low amounts of clove essential oil were also added to the most waterproof composite material (80 wt.% ethyl cellulose and 20 wt.% PDMS). The essential oil increased the flexibility and the antioxidant capacity of the composite. Finally, the antimicrobial properties were tested against common pathogens such as Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The presence of clove essential oil reduced the biofilm formation on the composites.
Cellulose-Metallothionein Matrix for Metal Binding Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-17 Naimat K. Bari, Shaswat Barua, Ankush Garg, Malay K. Sannigrahi, Sharmistha Sinha
Hydrothermal treatment of chestnut shells (Castanea sativa) to produce oligosaccharides and antioxidant compounds Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-17 Beatriz Gullón, Gemma Eibes, Izaskun Dávila, María Teresa Moreira, Jalel Labidi, Patricia Gullón
Hydrothermal treatment is an environmentally friendly technology that allows the solubilisation of hemicellulosic oligosaccharides with potential for their use as prebiotics. The purpose of this study was to solubilize oligosaccharides and antioxidant compounds from chestnut shells by a hydrothermal processing. The highest content of oligosaccharides (18.3 g/L), with a relatively low level of monosaccharides (2.4 g/L) and degradation products (0.5 g/L) was obtained at 180 °C (severity of 3.08). In addition, the liquors presented a high content of phenolic and flavonoid compounds with good antioxidant properties. The GC-MS revealed that the most abundant phenolic compound was pyrogallol (13.2%). The molecular weight distribution of the solubilization products showed that a 26.5% presented an apparent Mw of 6077 g/mol and a 73.5% presented an apparent Mw of 586 g/mol with a high polydispersity index. MALDI-TOF, FTIR, and TGA analyses revealed structural information of these compounds and their thermal stability.
Strengthening injectable thermo-sensitive NIPAAm-g-chitosan hydrogels using chemical cross-linking of disulfide bonds as scaffolds for tissue engineering Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-17 Shu-Wei Wu, Xifeng Liu, A. Lee Miller II, Yu-Shiuan Cheng, Ming-Long Yeh, Lichun Lu
In the present study, we fabricated non-toxic, injectable, and thermo-sensitive NIPAAm-g-chitosan (NC) hydrogels with thiol modification for introduction of disulfide cross-linking strategy. Previously, NIPAAm and chitosan copolymer has been proven to have excellent biocompatibility, biodegradability and rapid phase transition after injection, suitable to serve as cell carriers or implanted scaffolds. However, weak mechanical properties significantly limit their potential for biomedical fields. In order to overcome this issue, we incorporated thiol side chains into chitosan by covalently conjugating N-acetyl-cysteine (NAC) with carbodiimide chemistry to strengthen mechanical properties. After oxidation of thiols into disulfide bonds, modified NC hydrogels did improve the compressive modulus over 9 folds (11.4 kPa). Oscillatory frequency sweep showed the positive correlation between storage modulus and cross-liking density as well. Additionally, there was no cytotoxicity observed to mesenchymal stem cells, fibroblasts and osteoblasts. We suggested that the thiol-modified thermo-sensitive polysaccharide hydrogels are promising to be a cell-laden biomaterial for tissue regeneration.
Dissociation of chitosan/tripolyphosphate complexes into separate components upon pH elevation Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-16 Petra Mazancová, Veronika Némethová, Dušana Treľová, Lucia Kleščíková, Igor Lacík, Filip Rázga
Copper-mediated Homogeneous Living Radical Polymerization of Acrylamide with Waxy Potato Starch-based Macroinitiator Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-15 Yifei Fan, Huatang Cao, Frank van Mastrigt, Yutao Pei, Francesco Picchioni
Self-Healable Tough Supramolecular Hydrogels Crosslinked by Poly-Cyclodextrin through Host-Guest Interaction’ Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-15 Tingting Cai, Shuangjun Huo, Tao Wang, Weixiang Sun, Zhen Tong
Synthesis, physicochemical characterization and biological evaluation of chitosan sulfate as heparan sulfate mimics Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-15 Ernesto Doncel-Pérez, Inmaculada Aranaz, Agatha Bastida, Julia Revuelta, Celia Camacho, Niuris Acosta, Leoncio Garrido, Concepción Civera, Eduardo García-Junceda, Angeles Heras, Alfonso Fernández-Mayoralas
Despite the relevant biological functions of heparan sulfate (HS) glycosaminoglycans, their limited availability and the chemical heterogeneity from natural sources hamper their use for biomedical applications. Chitosan sulfates (ChS) exhibit structural similarity to HSs and may mimic their biological functions. We prepared a variety of ChS with different degree of sulfation to evaluate their ability to mimic HS in protein binding and to promote neural cell division and differentiation. The structure of the products was characterized using various spectroscopic and analytical methods The study of their interaction with different growth factors showed that ChS bound to the proteins similarly or even better than heparin. In cell cultures, a transition effect on cell number was observed as a function of ChS concentration. Differences in promoting the expression of the differentiation markers were also found depending on the degree of sulfation and modification in the chitosan.
Different strategies for cyclodextrin production: Ultrafiltration systems, CGTase immobilization and use of a complexing agent Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-15 Vanderson Carvalho Fenelon, Juliana Harumi Miyoshi, Camila Sampaio Mangolim, Aline Satomi Noce, Luciana Numata Koga, Graciette Matioli
The study comparatively evaluated diverse strategic models of cyclodextrin (CD) production by the CGTase of Bacillus firmus strain 37: continuous production and repetitive batches in ultrafiltration systems; immobilization of CGTase on curdlan and vegetable sponge natural supports; the use of the glycyrrhizin complexing agent to modulate CGTase selectivity in favor of γ-CD production. All strategies had in common the possibility of separation of CGTase from its inhibitory products and its reuse. In the continuous production model, at 48 h of assay, the highest productivity and selectivity for β-CD were obtained, 1.47 mmol/L/h and 92.8%, respectively. Glycyrrhizin was able to modulate the production of γ-CD with selectivity of 61.2% for 30-h batches. The comparative evaluation of the different strategic models for obtaining CDs showed particularities that should be considered, and most of the models studied returned satisfactory yields as well as excellent selectivity.
3D-macroporous chitosan-based scaffolds with in situ formed Pd and Pt nanoparticles for nitrophenol reduction Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-15 Dmitriy Berillo, Andrew Cundy
Study of steam explosion pretreatment and preservation methods of commercial cellulose Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-14 Ana Lorenzo Hernando, Judit Martín Juárez, Silvia Bolado Rodríguez
Steam explosion (150–200 °C, 5–30 min) was performed on a commercial cellulose presented in two configurations (fiberized and compact sheet) and its effect on their chemical and physical properties was studied, along with the influence of two different preservation methods (acetone drying and freezing) after pretreatment. No degradation compounds were produced during pretreatment, although solid recovery (RS) decreased with temperature from 90% to 62%. Similar particle size and surface conditions (increased porosity) were found for both types of pretreated samples despite the extremely different initial configuration. Crystallinity diminished for 150 °C samples, but 200 °C pretreatment promoted recrystallization. Pretreatment also reduced polymerization degree, although enzymatic accessibility did not improve. Both acetone and freezing processes extremely affected cellulose properties. Acetone drying counterbalanced crystallinity and enzymatic accessibility variations of pretreated samples, while decreasing polymerization degree to 302. Freezing dramatically decreased enzymatic accessibility of pretreated samples down to 15.8%.
Effect of pH and precursor salts on in situ formation of calcium phosphate nanoparticles in methylcellulose hydrogel Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-14 Min Hee Kim, Hanna Park, Won Ho Park
Protein Adsorption onto Polysaccharides: Comparison of Chitosan and Chitin Polymers Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-14 Mohammad Yahyaei, Faramarz Mehrnejad, Hossein Naderi-manesh, Ali Hossein Rezayan
Chitosan (CHS) and chitin (CHT) biopolymers have found many applications in the field of controlled-release drug delivery systems. Herein, molecular dynamics (MD) simulation and binding free energy calculations were used to investigate the potentials of CHS and CHT polymers for the controlled release of follicle-stimulating hormone (FSH). The results indicated that FSH conformation did not change in the presence of CHS and CHT. In addition, FSH-polymer interactions caused stability of the 310-helix structure of the alpha subunits of FSH (FSHα). Both the biopolymers interacted with the protein mainly through the hydrophobic forces. CHS has more affinity for FSH when compared with CHT. Furthermore, in both systems, the affinity of polymers for FSHα was more than that for beta subunits of FSH (FSHβ). The results suggested that the polysaccharides might improve the controlled-release FSH delivery.
Development and Characterisation of Hybrid Polysaccharide Membranes for Dehydration Processes Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-14 Inês T. Meireles, Rosa M. Huertas, Cristiana A.V. Torres, Isabel M. Coelhoso, João G. Crespo
The purpose of this work is the development and characterisation of new hybrid polysaccharide (FucoPol) membranes. These membranes were prepared by incorporation of a SiO2 network homogeneously dispersed by using a sol-gel method with GPTMS as a crosslinker silica precursor. They were further crosslinked with CaCl2 for reinforcement of mechanical properties and improvement of their permeation performance. They were characterised in terms of their structural, mechanical and thermal properties. They presented a dense and homogeneous structure, resistant to deformation, with a Tg of 43 °C and a thermal decomposition between 240–251 °C. The hybrid FucoPol membranes were tested for ethanol dehydration by pervaporation and also for nitrogen dehydration. They exhibited high water selectivity values, similar to PERVAP® 4101, however they lost their stability when exposed to solutions of 10.0 wt.% water in ethanol. In contrast, these membranes were stable when applied in N2 dehydration, leading to reproducible performance and very high water selectivities.
Synthesis and characterization of metal nanoparticles templated chitosan-SiO2 catalyst for the reduction of nitrophenols and dyes Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-14 Fayaz Ali, Sher Bahadar Khan, Tahseen Kamal, Khalid A. Alamry, Esraa M. Bakhsh, Abdullah M. Asiri, Tariq R.A. Sobahi
Carboxymethyl chitosan/gelatin/hyaluronic acid blended-membranes as epithelia transplanting scaffold for corneal wound healing Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-14 Wenhua Xu, Zheying Wang, Ying Liu, Liping Wang, Zhiwen Jiang, Tong Li, Wenhua Zhang, Ye Liang
There is an unmet need for an optimal scaffold as cell transplantation carrier to induce corneal reconstruction. In this study, a blend membrane was prepared with carboxymethyl chitosan (CMCTS), gelatin, and hyaluronic acid. To investigate its cytocompatibility, primary rabbit corneal epithelial cells (CEpCs) were seeded on it and growth and proliferation were evaluated. The blend membrane was found to be transparent, biodegradable, and suitable for CEpCs attachment and proliferation, which could maintain the epithelial cell-like protein expression of CEpCs. The combination of CEpCs and CMCTS-blended membrane (CEpCs/CMCTS membrane) was used to treat alkali-induced corneal damage in rabbits and healing effects were evaluated by visual observation, slit lamp, hematoxylin-eosin and immunofluorescence staining. CEpCs/CMCTS membrane could improve corneal epithelial reconstruction significantly and restore cornea transparency and thickness. Hence, this combination treatment may serve as a rapid and effective way for corneal wound healing.
Preparation of nano-sized particles from bacterial cellulose using ultrasonication and their characterization Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-14 Hairul Abral, Vincent Lawrensius, Dian Handayani, Eni Sugiarti
As more applications for nano-sized natural particles are discovered, simple, environmentally friendly ways to produce these particles become more important. This work prepares and characterizes nano-size bacterial cellulose particles using ultrasonication. Pellicle from nata de coco containing nanofibers was broken up in an electrical blender, then sonicated using an ultrasonic probe at 20 kHz and 3 watt/mL for 30, 60 and 90 min. Transmission electron microscope observations indicate the particles become nano-sized after 60 min ultrasound. The maximum decomposition temperature before sonication was 373 °C, decreased to 357 °C after 60 min ultrasonication. Moisture absorption of the 90 min sonicated particles film is 60% slower compared to non-sonicated particles. After ultrasonication, the crystallinity index of the cellulose decreases. The functional groups of non-sonicated and sonicated cellulose remain the same. This study promotes a potential method of fabrication of nano-sized particles from pure bacterial cellulose.
Starch film-coated microparticles for oral colon-specific drug delivery Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-14 Jin Chen, Xiaoxi Li, Ling Chen, Fengwei Xie
The aim of this study was to prepare and characterize a novel type of starch-coated microparticles (MPs) allowing site-specific delivery of bioactives to the colon. An oral colon-specific controlled-release system was developed in the form of MPs coated with a resistant starch (RS2/RS3) film (RS@MPs) through an aqueous suspension coating process. The RS2 was chosen from a high-amylose cornstarch with 88.5% digestion resistibility. The RS3 was prepared by a high-temperature/pressure (HTP) treatment, with the following of enzymatic debranching, and retrogradation, resulting in a dramatic increase in enzymatic resistance (RS3 content: 76.6%). RS@MPs showed 40.7% of 5-aminosalicylic acid release within 8 h. The in vivo study of fluorescein-loaded RS@MPs indicated the high acidic and enzymatic resistibility of RS@MPs and a restrained release in the upper GIT. Therefore, RS@MPs has revealed to be a high potential system for accurately targeting bioactive compound delivery to the colon.
Super Water Absorbing Polymeric Gel from Chitosan, Citric Acid and Urea: Synthesis and Mechanism of Water Absorption Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-14 Abathodharanan Narayanan, Ravishankar Kartik, Elanchezhian Sangeetha, Raghavachari Dhamodharan
A new superabsorbent with maximum water absorption capacity of ∼1250 g/g is prepared by hydrothermal synthesis from sustainable and biodegradable resources such as chitosan, citric acid and urea (denoted as ‘CHCAUR’). CHCAUR is characterized extensively by various analytical techniques such as PXRD, SSNMR, FTIR, and TGA. Pure and saline water absorption study showed that CHCAUR could be a better adsorbent compared to the super absorbent polymer (SAP) used in commercial diaper material. The mechanism of water absorption is shown to arise out of a combination of electrostatic attraction of water to the ionic crosslinks and the presence of macropores as well as undulated surface due to the formation of nanofibrous bundles. When applied to soil CHCAUR was found to decrease water evaporation rate significantly.
Polyethersulfone nanofiltration membrane embedded by chitosan nanoparticles: fabrication, characterization and performance in nitrate removal from water Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-14 Negin Ghaemi, Parisa Daraei, Farima Sadat Akhlaghi
In this research, chitosan nanobiopolymers (CS-NPs) were synthesized using tripoly phosphate and transferred into the organic solvent via solvent exchange method. Different amounts of chitosan nanopolymers were embedded into the polyethersulfone (PES) membrane prepared by phase inversion precipitation method. The membranes were employed for nitrate removal from water under various solution pHs (4.5, 7.0 and 9.0). Scanning electron microscopy, atomic force microscopy, porosity, water contact angle and pure water flux measurements were employed to characterize the fabricated membranes. Addition of chitosan nanoparticles into the membrane matrix increased the water permeability from 13 for pristine membrane to 22 kg/m2 h for modified membrane with 0.2 wt.% nanopolymer. However, the application of CS-NPs more than 0.4 wt.% led to membranes with a compact matrix and dense structure, thereby reducing water permeation even lower than PES. At all tested solution pHs, nitrate removal efficiency was significantly improved in comparison with pristine PES at as a result of adsorptive properties of chitosan biopolymer. The complete nitrate removal (100%) was achieved at acidic pH due to protonation of amine groups of CS-NPs creating positive charge on the membrane surface.
Cellulose nanocrystals from grape pomace: production, properties and cytotoxicity assessment Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-13 Caroline C.S. Coelho, Michele Michelin, Miguel A. Cerqueira, Catarina Gonçalves, Renata V. Tonon, Lorenzo M. Pastrana, Otniel Freitas-Silva, António A. Vicente, Lourdes M.C. Cabral, José A. Teixeira
Cellulose nanocrystals (CNCs) were obtained from grape pomace through chemical and physical pretreatments. Bleached cellulose pulp was subjected to acid hydrolysis (AH) for 30 or 60 min and an ultrasound treatment to obtain CNCs (AH30Sand AH60S). Compositional analyses of untreated (UGP) and pretreated (PGP) grape pomace showed the effectiveness of pretreatment in removing non-cellulosic components, recovering 80.1% cellulose in PGP (compared to 19.3% of UGP). Scanning and transmission electron microscopies were used to evaluate the CNCs morphology. AH in combination with ultrasound treatment led to needle-shaped structures and apparently more dispersed suspensions. Crystallinity index and thermal stability were studied by X-ray diffraction and thermogravimetric analysis, respectively. The AH60S sample presented high aspect ratio, crystallinity and thermal stability. CNCs toxicity was evaluated by exposing Caco-2 cells to CNCs suspension and evaluating their viability. Results showed that CNCs are non-toxic, opening the opportunity for their use on food and pharmaceutical applications.
Excellent reusable chitosan/cellulose aerogel as an oil and organic solvent absorbent Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-13 Zhanying Li, Lin Shao, Wenbin Hu, Tingting Zheng, Lingbin Lu, Yang Cao, Yongjun Chen
Absorption is one of the most important methods for oil spill cleanup. An ideal absorbent is expected to possess advantages of low cost, green, high absorption capacity and excellent reusability. In this paper, a new kind of cellulose aerogel was successfully fabricated via cellulose oxidation, crosslinking, freeze drying and cold plasma modification. The obtained aerogel (water contact angle up to 152.8°) exhibited outstanding oil/water selectivity and high absorption capacity (13.77–28.20 g/g) for various oils and organic solvents. What's more, this kind of aerogel could be reused by simple compression. The absorption-desorption process could be repeated for at least 50 cycles. Through the kinetic analysis, it was found that the pseudo-second order model was more appropriate for the aerogel’s oil absorption process. Owing to its low cost, hydrophobicity, high absorption capacity and excellent reusability, this kind of aerogel is expected to be used in oils and organic solvents spill cleanup and oil/water separation field.
Preparation and characterization of thermoplastic starch composites with fly ash modified by planetary ball milling Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-13 Tanjira Sundum, Katalin Mészáros Szécsényi, Kaewta Kaewtatip
Thermoplastic starch (TPS) composites were prepared containing different amounts of unmodified (UFA) or modified fly ash (MFA) powder. The modification of the fly ash was carried out by dry grinding UFA in a planetary ball mill at various speeds and grinding times. The particle size of the fly ash was determined with a laser particle size analyzer and a scanning electron microscope (SEM). It was found that the particle size of the UFA decreased from 59.60 μm to 13.17 μm after grinding for 1 h at 400 rpm. Both UFA and MFA powder were incorporated in a thermoplastic starch. The mechanical properties, water resistance, degradation under simulated weathering conditions and thermal properties of the TPS and the composites were characterized. The maximum tensile strength (7.78 MPa) was obtained in a composite with 2.50% of MFA. This value is about 9 times higher than the tensile strength of the TPS and 2 times higher than that of a TPS/UFA composite with 15.00% UFA. In addition, composites with MFA showed improved water resistance and delayed degradation compared to the TPS and the composites with UFA. The presence of UFA or MFA had a slight effect on the thermal stability of the samples. However, fly ash promoted the final phase of the thermal decomposition of starch indicating a possible catalytic activity.
A β-glucan from Durvillaea Antarctica has immunomodulatory effects on RAW264.7 macrophages via Toll-like receptor 4 Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-13 Yi Yang, Xiaoliang Zhao, Jia Li, Hao Jiang, Xindi Shan, Ya Wang, Wenbang Ma, Jiejie Hao, Guangli Yu
We studied the mechanisms underlying the immunostimulatory effects of aβ-1,3/1,6-glucan (BG136) from Durvillaea Antarctica. Our data showed that BG136 promoted the activation of MAPKs and NF-κB signaling pathways and cytokines production. BG136 did not increase MCP-1 or NO production or phosphorylation of NF-κB and MAPK in TLR4 siRNA knockdown cells, indicating that BG136 activates macrophages through TLR4. Flow cytometry analysis and confocal experiment showed that BG136 bound to TLR4 expressed on RAW264.7 macrophage cells surface. The affinity of BG136 for TLR4 was determined using Surface Plasmon Resonance (SPR) (KD: 4.51 × 10−6). Altogether, our results showed that BG136 activates RAW264.7 cells by binding to TLR4 and then triggering TLR4-mediated signaling pathways to promote cytokine secretion.
Isolation and characterisation of microcrystalline cellulose and cellulose nanocrystals from coffee husk and comparative study with rice husk Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-13 Sofía Collazo-Bigliardi, Rodrigo Ortega-Toro, Amparo Chiralt Boix
Cellulosic material from coffee husk has not been previously studied despite being a potential source of reinforcing agents for different applications. This material has been extracted and characterised from coffee husk, in parallel with previously studied rice husk. Samples have been analysed as to their ability to obtain cellulosic fibres and cellulose nanocrystals (CNC) by applying alkali and bleaching treatments and final sulphuric acid hydrolysis. Microstructural changes were analysed after treatments, and the size and aspect ratio of CNCs were determined. Crystallinity and thermal stability of both materials progressed in line with the enrichment in cellulosic compounds. The CNC aspect ratio was higher than 10, which confers good reinforcing properties. These were tested in thermoplastic starch films, whose elastic modulus increased by 186 and 121% when 1 wt% of CNCs from rice and coffee husks, respectively, was incorporated into the matrix. Coffee husk represents an interesting source of cellulosic reinforcing materials.
Bio-inspired hydrophobic modification of cellulose nanocrystals with castor oil Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-13 Qianqian Shang, Chengguo Liu, Yun Hu, Puyou Jia, Lihong Hu, Yonghong Zhou
Antifouling zwitterionic dextran micelles for efficient loading DOX Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-13 Xiaotian Wu, Xiaofeng Chen, Peibo Hu, Minghong Hou, Yahao Dong, Yuping Wei
Polysaccharides derivatives are typical drug nanocarriers which are nontoxic and biodegradable. However, as is the case for all drug delivery systems, polysaccharides derivatives have to face the issue of protein fouling. In this paper, we present the design and synthesis of carboxybetaine-modified dextran-polycaprolactone (CB-Dex-PCL) copolymers as doxorubicin (DOX) nanocarriers. Results showed that DOX/CB-Dex-PCL micelles exhibited better cumulative release at the pH value of 5.2 than at the physiological pH of 7.4, which indicated potential applications in killing tumor cells while minimizing the toxicity to normal tissues. Additionally, antifouling properties of carboxybetaine functionalized dextran micelles were much better than that of unmodified dextran for fibrinogen and lysozyme as tested by ITC. Finally, cytotoxicity tests using Hela cells showed that CB-Dex-PCL and DOX-loaded micelles exhibited great biocompatibility. All the above observations indicated that CB-Dex-PCL micelles are potentially excellent drug carriers for the treatment of human cancerous tumors.
Superhydrophobic three-dimensional porous ethyl cellulose absorbent with micro/nano-scale hierarchical structures for highly efficient removal of oily contaminants from water Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-12 Yeqiang Lu, Weizhong Yuan
Carboxymethyl guar gum synthesis in homogeneous phase and macroporous 3D scaffolds design for tissue engineering Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-11 Sonia Kundu, Aatrayee Das, Aalok Basu, Debjani Ghosh, Pallab Datta, Arup Mukherjee
Preparation and Characterization of Nanocomposite Films from Oil Palm Pulp Nanocellulose/Poly (Vinyl alcohol) by Casting Method Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-11 Mohammad Asad, Naheed Saba, Abdullah M. Asiri, M. Jawaid, Eti Indarti, W.D. Wanrosli
TEMPO-oxidize nanocellulose (TONC) suspension has been obtained from total chlorine free (TCF) oil palm empty-fruit-bunches (OPEFB) pulp using 4-acetamido-TEMPO (2,2,6,6-tetramethyl piperidin-1-oxyl) mediated oxidation with sodium hypochlorite and sodium bromide in water at 25 °C and pH 10. TONC suspension with varied content from 0.5 to 6% (w/w) reinforced polyvinyl alcohol (PVA) polymer based nanocomposite films were prepared by the casting method. The structural interaction between the TONC and PVA was characterized by the Fourier transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that the 4% (w/w) TONC content reinforced nanocomposite exhibited the highest tensile strength and modulus with an increase of 122% and 291% respectively, compared to PVA while the elongation at break decreased about 42.7%. Thermal stability of PVA based nanocomposite films was improved after incorporation of TONC. Incorporation of TONC in PVA film increases its crystallinity due to strongly linking between the hydroxyl groups of materials however considerable decreases beyond 2 wt% loading are observed. TONC incorporation beyond 2 wt% also reduces the melting temperature peaks and enthalpy of nanocomposite films. FT-IR spectra, NMR and SEM indicate that there is interaction between the TONC and PVA.
Antioxidant and antimicrobial methylcellulose films containing Lippia alba extract and silver nanoparticles Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-10 Michael Ramos Nunes, Mércia de Souza Maguerroski Castilho, Ana Paula de Lima Veeck, Cleonice Gonçalves da Rosa, Carolina Montanheiro Noronha, Matheus V.O.B. Maciel, Pedro Manique Barreto
Methylcellulose is a biopolymer, which can be used in the preparation of films for the production of biodegradable active packaging. In this work, the methylcellulose films containing biosynthesized silver nanoparticles (AgNPs) were developed using Lippia alba extract. The physico-chemical, antioxidant, and antimicrobial properties of the films were studied. The insertion of Lippia alba compounds was verified using infrared spectroscopy (FTIR), with the appearance of a band at 1595 cm−1 and 1410 cm−1 which is characteristic of C C C stretches of the aromatic ring, and the increase in the hydrophobicity of the films containing the extract in relation to the control film. The films containing AgNPs presented a decrease in tensile strength and elastic modulus, but increased elongation. It was observed that the films that contain AgNPs presented superior antioxidant activity compared to the other films, besides antimicrobial activity against the tested microorganisms.
Engineering of thermoresponsive gels as a Fake Metastatic Niche Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-10 Simona Giarra, Caterina Ierano, Marco Biondi, Maria Napolitano, Virginia Campani, Roberto Pacelli, Stefania Scala, Giuseppe De Rosa, Laura Mayol
Chemoattraction through the CXCR4-CXCL12 axis has been shown to be an important mechanism to direct circulating tumor cells toward distant sites. The objective of this work was to prepare a fake metastatic niche made up of a gel loaded with CXCL12. The gel is designed to create a steep concentration gradient of the chemokine in the proximity of the site of administration/injection, aimed to divert and capture circulating CXCR4+ tumor cells. To this aim, different thermoresponsive gels based on methylcellulose (MC) or poloxamers, loaded with CXCL12, with or without hyaluronic acid (HA) were designed and their mechanical properties correlated with the ability to attract and capture in vitro CXCR4+ cells. Results of in vitro cell studies showed that all prepared gels induced CEM tumor cell migration whereas only gels based on MC embedded with CXCL12 are able to capture them.
AgBr and AgCl nanoparticle doped TEMPO-oxidized microfiber cellulose as a starting material for antimicrobial filter † Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-10 Sumit S. Lal, Shashank T. Mhaske
Present work covers the state-of-art progress in the advanced nanoarchitecture of organic-inorganic hybrid material; a starting material for the antimicrobial filter. TEMPO-mediated oxidation of microfiber cellulose was carried out to introduce the surface active carboxyl groups. Accordingly, qualitative and quantitative substitution of a functional group was investigated using FTIR, Solid state 13C CP/MAS NMR, and potentiometric titration; the reaction resulted to about 21.06% increase in carboxylate content. Further, the microwave irradiated (600W) in-situ synthesis of AgBr and AgCl nanocubes were prepared and doped on carboxylated microfiber. The prepared AgBr@TO-MF and AgCl@TO-MF were tested using XRD, XPS, SEM and FTIR. With an average size of AgBr and AgCl nanocubes of around 200 ± 28 nm and 116 ± 10.73 nm. Whereas, AgBr@TO-MF and AgCl@TO-MF shown excellent antimicrobial activity against E. Coli and B. Subtilis, with MIC at around 200 μg/mL and 150 μg/mL, respectively. Fascinatingly, ICP-OES analysis estimated the silver leached was around 0.1 ppm.
Enzymatic Biopolishing of Cotton Fabric with Free/Immobilized Cellulase Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-09 Nisha Sankarraj, Gobi Nallathambi
Cotton fabric was biopolished using free and immobilized cellulase. The immobilized cellulase treatment results lower weight loss and minimum reduction in tensile strength of the fabric at the minimum of 67% and a maximum of 98.35% and better whiteness index when compared with free cellulase treatment. Regression analysis was carried out for all properties, regression coefficients and summary of fit have been discussed. Both free and immobilized cellulase treated fabrics showed improved crystallinity index and it was analyzed by XRD. FTIR spectra were obtained to measure the hydrogen bonding intensity, which showed that the intensity values were decreased after treatment. The study confirms that the treatment with immobilized cellulase improves the surface properties without affecting the strength of fabric than the fabric treated with free cellulase.
Multi-hierarchical tissue-engineering ECM-like scaffolds based on cellulose acetate with collagen and chitosan fillers Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-09 Ksenia I. Lukanina, Timofei E. Grigoriev, Sergey V. Krasheninnikov, Vissarion G. Mamagulashvilli, Roman A. Kamyshinsky, Sergey N. Chvalun
Distinct wall polymer deconstruction for high biomass digestibility under chemical pretreatment in Miscanthus and rice Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-09 Yuyang Li, Jingdi Zhuo, Peng Liu, Peng Chen, Huizhen Hu, Youmei Wang, Shiguang Zhou, Yuanyuan Tu, Liangcai Peng, Yanting Wang
Miscanthus is a leading bioenergy crop and rice provides enormous biomass for biofuels. Using Calcofluor White staining, this work in situ observed an initial lignocellulose hydrolysis in two distinct Miscanthus accessions, rice cultivar (NPB), and Osfc16 mutant after mild chemical pretreatments. In comparison, the M. sin and Osfc16 respectively exhibited weak Calcofluor fluorescence compared to the M. sac and NPB during enzymatic hydrolysis, consistent with the high biomass saccharification detected in vitro. Using xyloglucan-directed monoclonal antibodies (mAbs), xyloglucan deconstruction was observed from initial cellulose hydrolysis, whereas the M. sin and Osfc16 exhibited relatively strong immunolabeling using xylan-directed mAb, confirming previous findings of xylan positive impacts on biomass saccharification. Furthermore, the M. sin showed quick disappearance of RG-I immunolabeling with varied HG labelings between acid and alkali pretreatments. Hence, this study demonstrated a quick approach to explore wall polymer distinct deconstruction for enhanced biomass saccharification under chemical pretreatment in bioenergy crops.
Adsorption study of Methyl orange by Chitosan/Polyvinyl Alcohol/Zeolite Electrospun Composite Nanofibrous Membrane. Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-07 Umma Habiba, Tawsif A. Siddique, Jacky Jia Li Lee, Tan Chin Joo, Bee Chin Ang, Amalina M. Afifi
The chitosan/polyvinyl Alcohol/zeolite electrospun composite nanofibrous membrane was fabricated for adsorption of methyl orange. The EDX, TGA and tensile test were carried out for the characterization of the membrane. The Young’s Modulus of the nanofibrous membranes increased by more than 100% with the addition of zeolite to chitosan/PVA. The batch adsorption tests were conducted by varying the initial concentration of methyl orange, contact time and pH of the dye solution. UV–vis results showed that most of the dye was adsorbed within 6 min. An adsorption kinetic study was carried out using the pseudo-second-order kinetic model, Lagergren-first-order model and intra particle diffusion model. The adsorption kinetics obeyed the Pseudo second order model. The adsorption mechanism was analyzed using the Langmuir and Freundlich isotherm model. The experimental data fits well with the Freundlich model. The adsorption capacity of the membrane was 153 mg/g. Adsorption capacity was decreased with increasing pH value. The resulting nanofiber became less active over methyl orange after several runs.
Cellulose nanofibers isolated by TEMPO-oxidation and aqueous counter collision methods Carbohydr. Polym. (IF 4.811) Pub Date : 2018-03-07 Le Van Hai, Lindong Zhai, Hyun Chan Kim, Jung Woong Kim, Eun Sik Choi, Jaehwan Kim
In this research, cellulose nanofiber (CNF) was isolated by the combination of chemical 2,2,6,6-tetramethylpiperidine-1-oxylradical (TEMPO)-oxidation and physical aqueous counter collision (ACC) methods The combination of TEMPO-oxidation and ACC is an efficient method to isolate CNFs by reducing chemical usage in TEMPO-oxidation and saving energy in ACC along with controlling the size of CNFs. Two cellulose sources, hardwood bleached kraft pulp (HW) and softwood bleached kraft pulp (SW), were used for the CNF isolation with different TEMPO oxidation time and a defined number of ACC pass. The CNF properties were investigated and compared in term of morphology, crystallinity index, transparency and birefringence. The width of the isolated CNFs from HW is in the range of 15.1 nm–17.5 nm, and that of the SW CNFs is between 18.4 nm and 22 nm depending on the TEMPO oxidation time. This difference is due to the fact that SW is less oxidized than HW under the same chemical dosage, which results in larger width of SW-CNFs than HW-CNFs. The HW-CNF treated with TEMPO for over 2 hours and isolated using ACC with 5 pass offers almost 90% transparency. Birefringence of CNFs exhibits that HW-CNFs show better birefringence phenomenon than SW-CNFs. The combination of TEMPO-oxidation and ACC methods is useful for isolating CNFs with its size control.
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