Carbohydrate Polymers (v.90, #4)
Editorial Board (CO3).
Anticancer polysaccharides from natural resources: A review of recent research by Aizhen Zong; Hongzhi Cao; Fengshan Wang (1395-1410).
► A large amount of natural polysaccharides have anticancer activities. ► Polysaccharides inhibit tumor growth by direct toxicity and immunomodulation. ► Mushroom glucans enhance the efficacy and reduce the toxicity of chemotherapy.Taking into account the rising trend of the incidence of cancers of various organs, effective therapies are urgently needed to control human malignancies. However, almost all of the chemotherapy drugs currently on the market cause serious side effects. Fortunately, several previous studies have shown that some non-toxic biological macromolecules, including polysaccharides and polysaccharide–protein complexes, possess anti-cancer activities or can increase the efficacy of conventional chemotherapy drugs. Based on these encouraging observations, a great deal of effort has been focused on discovering anti-cancer polysaccharides and complexes for the development of effective therapeutics for various human cancers. This review focuses on the advancements in the anti-cancer efficacy of various natural polysaccharides and polysaccharide complexes in the past 5 years. Most polysaccharides were tested using model systems, while several involved clinical trials.
Keywords: Polysaccharides; Polysaccharide–protein complexes; Anticancer;
Studies on the characteristic and activity of low-molecular fragments from zymosan by Yang Gao; Ruizhi Jiang; Jing Qie; Yinghong Chen; Duoduo Xu; Wei Liu; Qipin Gao (1411-1414).
► Zymosan was hydrolysed and fractionated to obtain water-soluble fragments A, B and C. ► These fractions are composed primarily of β-1,3-glucans. ► And have molecular weights of 8 kDa, 5 kDa and 2 kDa, respectively. ► And fragment A (molecular weight is 8 K) has the significant activity.Zymosan was hydrolysed with HCl and fractionated by ultrafiltration and dialysis to obtain water-soluble fragments A, B and C. Physical and chemical analyses showed that these fractions are composed primarily of glucose and have molecular weights of 8 kDa, 5 kDa and 2 kDa, respectively. A glycosidic linkage analysis indicated that they are mainly composed of β-1,3-glucans. Fragment A, which has the highest molecular weight, contains approximately 30% β-1,6-linked glucans, but fragment C is almost entirely composed of linear β-1,3-glucan chains. The anti-chronic atrophic gastritis activity experiments showed that fragment A has significant activity, the activity of zymosan is quite low and the activities of fragments B and C are in between those of fragment A and zymosan.
Keywords: Zymosan; Glycosidic linkage; Anti-chronic atrophic gastritis activity;
Bromide-free oxidizing system for carboxylic moiety formation in cellulose chain by Sergiu Coseri; Gabriela Biliuta (1415-1419).
► NHPI (N-hydroxyphthalimide) and copper chloride (II) were used as efficient mediators for the cellulose fibers oxidation. ► No sodium bromide is required for this oxidation protocol, thus eliminating the corrosion and environmental concerns. ► Carboxylic group's formation was determined by potentiometric titration and X-ray photoelectron spectroscopy.NHPI (N-hydroxyphthalimide) was used to mediate the oxidation of cellulose fibers in the absence of sodium bromide, as traditionally was used in this kind of transformations, solely using sodium hypochlorite (NaOCl) as the primary oxidant. Avoiding the use of NaBr is highly desired from both environmental and corrosion concerns. The non-persistent PINO (phthalimide-N-oxy) radical, the key species in the oxidation reaction, has been in situ generated from NHPI and copper (II) chloride. The reaction was performed at room temperature at pH = 10.5. The carboxylic moiety formation was evidenced by FTIR and X-ray photoelectronic spectroscopy (XPS) and the content of the negatively charged groups determined by potentiometric titration. The changes appeared in crystallinity were evidenced by X-ray diffraction technique.
Keywords: Biopolymers; Biocomposites; Viscose fibers; Oxidation; N-hydroxyphthalimide; NHPI;
Ultrasound-assisted adsorption of anionic nanoscale pigment on cationised cotton fabrics by Longyun Hao; Rui wang; Jingquan Liu; Rongzhan Liu (1420-1427).
► A stable nanoscale pigment dispersion was prepared by a polymeric dispersant. ► The ultrasound can improve the equilibrium adsorption of nanoscale pigment. ► The ultrasound facilitates the diffusion of pigment through the boundary layer. ► The time needed for the adsorption of pigment can be reduced by ultrasound. ► The ultrasound can prevent the pigment from aggregating on the cotton surface.Application of pigments in textile coloring has many advantages such as less water and energy consumption, less effluent load and higher efficiency, so the pigments are perfect alternatives to dyes for eco-friendly coloring. In this work, a stable anionic nanoscale pigment suspension was prepared using a polymeric dispersant to color the cationised cotton with the exhaust method. Meanwhile, ultrasound was carried out during the adsorption to evaluate the ultrasonic influences on the uptake of pigment, adsorption efficiency and final product quality. The uptake of pigment is found to be higher with ultrasonic method than that with conventional technique because of the good dispersing capacity of ultrasound to pigment particles. Besides, it is found that nanoscale pigment has higher adsorption rate when using ultrasonic method because the ultrasound promotes the diffusion of pigment through the fiber–liquid boundary layer. Lastly, the color difference (ΔE) reveals the nanoscale pigment can be deposited on cotton surface more uniformly under ultrasonic condition, improving the product quality obviously.
Keywords: Ultrasound; Polymeric dispersant; Nanoscale pigment; Adsorption; Cationised cotton;
Dextran and gelatin based photocrosslinkable tissue adhesive by Tao Wang; Jun Nie; Dongzhi Yang (1428-1436).
► Photocrosslinkable gels were prepared from oxidized urethane dextran and gelatin. ► Gelatin remarkably increased the adhesive strength and decreased the swelling ratio. ► Double crosslinking helped decrease the swelling ratio and enhance cell attachment. ► These gels can be used as a novel tissue adhesive.A two-component tissue adhesive based on biocompatible and bio-degradable polymers (oxidized urethane dextran (Dex-U-AD) and gelatin) was prepared and photocrosslinked under the ultraviolet (UV) irradiation. The adhesive could adhere to surface of gelatin, which simulated the human tissue steadily. The structures of above Dex-U-AD were characterized by FTIR, 1H NMR spectroscopy and XRD. The adhesion property of result products was evaluated by lap-shear test. The maximum adhesion strength could reach to 4.16 ± 0.72 MPa which was significantly higher than that of fibrin glue. The photopolymerization process of Dex-U-AD/gelatin was monitored by real time infrared spectroscopy (RTIR). It took less than 5 min to complete the curing process. The cytotoxicity of Dex-U-AD/gelatin also was evaluated which indicated that Dex-U-AD/gelatin gels were nontoxic to L929 cell. The relationship between all the above-mentioned properties and degree of oxidization of Dex-U-AD was assessed. The obtained products have the potential to serve as tissue adhesive in the future.
Keywords: Dextran; Oxidization; Gelatin; Tissue adhesive; Photocrosslinking;
Starch/polyaniline nanocomposite for enhanced removal of reactive dyes from synthetic effluent by V. Janaki; K. Vijayaraghavan; Byung-Taek Oh; Kui-Jae Lee; K. Muthuchelian; A.K. Ramasamy; Seralathan Kamala-Kannan (1437-1444).
► Starch/polyaniline nanocomposite – an eco-friendly polymer matrix for the treatment of dye bath effluents. ► The nanocomposite decolorized 87% of dye bath effluent. ► The removal of dyes is largely depending on the solution pH. ► The removal process followed Freundlich isotherm and pseudo-first order kinetics.Starch/polyaniline nanocomposite was synthesized by chemical oxidative polymerization of aniline and was subsequently analyzed for dye removal from aqueous solution. Batch experiment results showed that nanocomposite removed 99% of Reactive Black 5, 98% of Reactive Violet 4, and decolorized 87% of dye bath effluent. The Toth isotherm model better described single component equilibrium adsorption, whereas the modified Freundlich model showed satisfactory fit for dye bath. In kinetic modeling, single system followed pseudo-second-order and dye bath followed the modified pseudo-first-order model. Fourier transform infrared spectroscopy pattern of the nanocomposite showed the participation of aromatic, amino, hydroxyl, and carboxyl groups. The results indicate that starch/polyaniline nanocomposite can be used as an effective adsorbent for removal of dyes from textile effluents.
Keywords: Biosorption; Dye bath; Nanocomposite; Polyaniline; Reactive dyes; Starch;
Electrospun poly(lactic acid)/chitosan core–shell structure nanofibers from homogeneous solution by Yajing Li; Fan Chen; Jun Nie; Dongzhi Yang (1445-1451).
► Homogenous solution was prepared by mixing hydrophilic polymer and hydrophobic polyester. ► Core–shell structure nanofibers were prepared by single nozzle electrospinning. ► A simple method was used to remove SDS which modified CS on the surface of nanofibers, then CS in shell layer was revealed. ► Cell culture and adhesion showed good biocompatibility of these nanofibrous membranes.The core–shell structure nanofibers of poly(lactic acid)/chitosan with different weight ratios were successfully electrospun from homogeneous solution. The preparation process was more simple and effective than double-needle electrospinning. The nanofibers were obtained with chitosan in shell while poly(lactic acid) in core attributing to phase separation, which were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive spectrometer (EDS). The electrospun nanofibrous membrane was evaluated in vitro by using mouse fibroblasts (L929) as reference cell lines. Cell culture results indicated that these materials were good in promoting cell growth and attachment, thus they could be used for tissue engineering and wound healing dressing.
Keywords: Core–shell structure; Electrospinning; Poly(lactic acid); Homogeneous solution; Chitosan;
Films of starch and poly(butylene adipate co-terephthalate) added of soybean oil (SO) and Tween 80 by Renata P. Herrera Brandelero; Maria Victória Grossmann; Fabio Yamashita (1452-1460).
► This study characterized films made from blends of TPS/PBAT with SO and the Tween 80. ► The SO proved to be compatible with TPS/PBAT blends. ► Films added of SO improved the mechanical properties and microstructure. ► The addition of SO increased the chemical interaction among polymers. ► The SO improvised processability of films by balloon-blowing system.Starch extruded in the presence of a plasticizer results in a material called thermoplastic starch (TPS). TPS mixed with poly(butylene adipate co-terephthalate) (PBAT), soybean oil (SO), and surfactant may result in films with improved mechanical properties due to greater hydrophobicity and compatibility among the polymers. This study characterized films produced from blends containing 65% TPS and 35% PBAT with SO added as compatibilizer. The Tween 80 was added to prevention of phase separation. The elongation and resistance were greater in the films with SO. The infrared spectra confirmed an increase in ester groups bonded to the PBAT and the presence of groups bonded to the starch ring, indicating TPS–SO and PBAT–SO interactions. The micrographs suggest that the films with SO were more homogenous. Thus, SO is considered to be a good compatibilizer for blends of TPS and PBAT.
Keywords: Biodegradable films; Extrusion blow molding; Blends; Surfactant; Lipids;
Imaging of the GI tract by QDs loaded heparin–deoxycholic acid (DOCA) nanoparticles by Zehedina Khatun; Md. Nurunnabi; Kwang Jae Cho; Yong-kyu Lee (1461-1468).
► It is the first ever formulation for oral delivery of quantum dots. ► The Q-LHD nanoparticles absorbed in ileum of small intestine which has been observed by imaging technique. ► Absorption, biodistribution, metabolism and elimination of Q-LHD nanoparticles observed by imaging process. ► QDs loaded LHD nanoparticles absorbed through interaction between DOCA and bile acid receptors of small intestine.This study presents an approach to deliver non invasive, near-IR imaging agent using oral delivery system. Low molecular weight heparin (LMWH)–deoxycholic acid (DOCA)/(LHD) nanoparticles formed by a self-assembly method was prepared to evaluate their physicochemical properties and oral absorption in vitro and in vivo. Near-IR QDs were prepared and loaded into LHD nanoparticles for imaging of the gastro-intestinal (GI) tract absorption. Q-LHD nanoparticles were almost spherical in shape with diameters of 194–217 nm. The size and fluorescent intensity of the Q-LHD nanoparticles were stable in 10% FBS solution and retained their fluorescent even after 5 days of incubation. Cell viability of Q-LHD nanoparticles maintained in the range of 80–95% for 24 h incubation. No damage was found in tissues or organs during animal experiments. The in vivo oral absorption of Q-LHD was observed in SKH1 mice for 3 h under different doses. From the results, we confirmed that Q-LHD was absorbed mostly into the ileum of small intestine containing intestinal bile acid transporter as observed in TEM and molecular imaging system. Our designed nanoparticles could be administered orally for bio-imaging and studying the bio-distribution of drug.
Keywords: Heparin; Oral delivery; GI tract; In vivo imaging; Near-IR QDs;
Electrosprayed polyelectrolyte complexes between mucoadhesive N,N,N,-trimethylchitosan-homocysteine thiolactone and alginate/carrageenan for camptothecin delivery by Kotchakorn Juntapram; Nalena Praphairaksit; Kritsana Siraleartmukul; Nongnuj Muangsin (1469-1479).
► Novel polyelectrolyte complexes of mucoadhesive thiolated chitosan were first developed. ► Microspheres thiolated quaternized chitosan/alginate PEC can be easily formed by electrospray. ► Thiolated chitosan/alginate exhibited good swelling behavior and sustained release of drug. ► They might be suitable polymers for drug delivery systems in any mucus site organs.Novel hydrogel polyelectrolyte complexes (PECs) between the N,N,N,-trimethylchitosan-homocysteine thiolactone (TM-HT-chitosan) and two anionic polymers were investigated. The particles of pure thiolated chitosan and its PECs with alginate and carrageenan were fabricated using the electrospray ionization technique. The hydrogel PEC particles were characterized by scanning electron microscopy, dynamic light scattering, Fourier transform infrared microscopy, thermogravimetric analysis, encapsulation efficiency (EE), mucoadhesive property and in vitro drug release behavior. TM-HT-chitosan/alginate particles could be loaded with camptothecin (CPT), employed as a model anti-cancer drug, at an over 70% EE, and revealed both a reduced burst effect and a prolonged release of CPT over 3 days. The resultant TM-HT-chitosan/alginate PEC particles displayed a 5.60-, 1.86- and 1.55-fold stronger mucoadhesive property compared to that of the unmodified chitosan/alginate PEC at pH 1.2, 4.0 and 6.4, respectively, and this was not affected by the CPT loading level.
Keywords: N,N,N,-trimethyl chitosan; Thiolated chitosan; Alginate; Polyelectrolyte complexes; Drug delivery; Electrospray ionization technique;
Effect of γ-irradiation on pasting and emulsification properties of octenyl succinylated rice starches by Jung-Ah Han; Seung-Taik Lim (1480-1485).
► OS starch showed different results by irradiation according to amylose content. ► Irradiation decreased pasting properties, especially in waxy rice starch. ► Higher dose (50 kGy at this research) degraded the starch chains as well as OS groups, resulting in crystallinity decrease. ► 10 kGy irradiation was seemed to be a good method for effective OS rice dextrin.Octenylsuccinylated (OS) starches from waxy rice or high-amylose rice (28.1% amylose) (DS 0.023 and 0.025, respectively) were gamma-irradiated at 10, 30, or 50 kGy and their pasting and thermal properties, crystallinity, and emulsification property were examined. When the OS starches were irradiated, the degrees of substitution gradually decreased as irradiation dose increased. A significant decrease in pasting viscosity was observed with an increase in irradiation dose, indicating the presence of chain degradation induced by the radiation. The melting temperature and enthalpy determined by differential scanning calorimetry increased slightly by irradiating at 10 or 30 kGy. Little change in crystallinity was observed in the X-ray diffraction analysis for the OS high-amylose rice starch regardless of irradiation doses, whereas a decrease in crystallinity was observed with the OS waxy starch irradiated at 50 kGy. Chain degradation induced by irradiation occurred mainly in the amorphous regions, but some loss of crystallinity occurred when the irradiation was excessive. The OS starches showed greater emulsion capacity and stability than the native counterparts due to their amphipathic nature. The irradiation further improved the emulsification properties of OS starches. The irradiation at 10 kGy was optimal, and treating at higher doses decreased the emulsion capacity and stability of the OS starches.
Keywords: Octenylsuccinylated rice starch; Gamma irradiation; Pasting properties; Emulsion capacity;
Preparation and characterization of novel oxidized cellulose acetate methyl esters by D. Yang; V. Kumar (1486-1493).
► The methyl ester of OCA (OCAM) was successfully prepared from oxidized cellulose acetate (OCA). ► The viscosity-average molecular weights of the polymers were from ∼38,349 to ∼27,524. ► Powder X-ray diffraction studies revealed that OCAMs are low crystallinity materials. ► OCAM shows the highest solubility of 211–280 mg/ml in chloroform. ► The moisture sorption ability decreases significantly with acetylation and methylation of OC.In this paper, we report the preparation of oxidized cellulose acetate methyl esters (OCAM) from OCA (OC14A: carboxylic acid content 10.6% (w/w), degree of acetyl group substitution: 1.89; OC21A: carboxylic acid content 15.7% (w/w), degree of acetyl group substitution: 1.70) by treatment with methanol at room temperature using 4-dimethylaminopyridine (DMAP) as a catalyst and dicyclohexylcarbodiimide (DCC) as a coupling agent. The new polymers were characterized by Fourier-transform infrared (FT-IR) and 1H and 13C nuclear magnetic resonance spectroscopies, carboxylic acid content determination, moisture sorption isotherms, intrinsic viscosity, and powder X-ray diffractometry. The new polymers are amorphous powders. It is practically insoluble in water but show solubility in a range of organic solvents.
Keywords: Oxidized cellulose; 6-Carboxycellulose; Oxidized cellulose acetates; Oxidized cellulose acetate alkyl esters; Oxidized cellulose acetate methyl esters; Oxidized cellulose esters; 6-Carboxycellulose esters;
In vitro evaluation of an RGD-functionalized chitosan derivative for enhanced cell adhesion by Annasara Hansson; Nour Hashom; Françoise Falson; Patricia Rousselle; Olivier Jordan; Gerrit Borchard (1494-1500).
► A chitosan derivative was synthesized and characterized. ► The chitosan derivative was successfully functionalized with RGD peptides. ► Novel polymer shows good biocompatibility in vitro. ► The derivative increases the level of adhesion and the spreading of cells.Tissue repair is a spontaneous process that is initiated on wounding. However, if this complex mechanism is impaired or not sufficient the use of biomaterials might increase the chance of successful healing. In this view, an RGD-functionalized polymer was developed to promote dermal healing. A water-soluble chitosan derivative, carboxymethyl-trimethylchitosan (CM-TM-chitosan) was synthesized and GRGDS-moieties were grafted to the backbone at a concentration of 59 nmol/mg polymer to increase cell–biomaterial interaction. Tested in vitro with cultured human dermal fibroblasts, the developed polymer showed good biocompatibility and the initial adhesion was increased by 3–5 times due to the GRGDS-moieties. Moreover, cell spreading was specific to the interaction with GRGDS, giving a 12-fold increase of cells showing a fully spread morphology within 30 min. Overall, CM-TM-chitosan conjugated with GRGDS-peptides may prove useful as a biomaterial in wound healing.
Keywords: Wound healing; Human dermal fibroblast; Chitosan; RGD peptide; Cell adhesion;
A new route for chitosan immobilization onto polyethylene surface by Anton Popelka; Igor Novák; Marián Lehocký; Ita Junkar; Miran Mozetič; Angela Kleinová; Ivica Janigová; Miroslav Šlouf; František Bílek; Ivan Chodák (1501-1508).
► New route for polysaccharide immobilization applying plasma treatment. ► Introducing oxygen-based functional groups on the polymeric surface. ► Increase of surface roughness as well as surface free energy. ► Antibacterial efficiency indicating by effective bacterial inhibition zone (35 mm2 for E. coli and 275 mm2 for S. aureus).Low-density polyethylene (LDPE) belongs to commodity polymer materials applied in biomedical applications due to its favorable mechanical and chemical properties. The main disadvantage of LDPE in biomedical applications is low resistance to bacterial infections. An antibacterial modification of LDPE appears to be a solution to this problem. In this paper, the chitosan and chitosan/pectin multilayer was immobilized via polyacrylic acid (PAA) brushes grafted on the LDPE surface. The grafting was initiated by a low-temperature plasma treatment of the LDPE surface. Surface and adhesive properties of the samples prepared were investigated by surface analysis techniques. An antibacterial effect was confirmed by inhibition zone measurements of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The chitosan treatment of LDPE led to the highest and most clear inhibition zones (35 mm2 for E. coli and 275 mm2 for S. aureus).
Keywords: Immobilization; Plasma treatment; Chitosan; Pectin; Multilayer; Grafting;
β-Chitin nanofibrils for self-sustaining hydrogels preparation via hydrothermal treatment by Iryanti Fatyasari Nata; Steven Sheng-Shih Wang; Tsai-Mao Wu; Cheng-Kang Lee (1509-1514).
► Chitin nanofibrils (CNF) suspension easily prepared from squid pen by sonication irradiation. ► Heating 1% (w/v) CNF suspension at 180 °C for 4 h generated durable 3D hydrogels. ► Hydrophobic interactions promoted the self-assembly of CNF into hydrogels. ► The hydrogels can be easily cross-linked by a cytocompatible cross-linker genipin.A transparent nanofibril suspension could be readily obtained by treating purified squid pen powder in water with ultrasonic irradiation. The obtained suspension is consisted of β-chitin nanofibrils (CNF) with 3–10 nm in width and several micrometers in length. The degree of acetylation (DA) of CNF was found to be 84% which is about 10% lower than that of untreated sample. The CNF suspension could be transformed into a durable 3-D hydrogels (CH) by simply heating to 180 °C for 1–4 h in an autoclave. Hydrophobic interaction between CNF was believed to play the major role for CNF self-assembling into hydrogels, since the as-prepared chitin hydrogels readily dissolved in a typical chaotropic solution (8 M urea) under room temperature. The hydrothermal duration and CNF concentration (0.3–2% (w/v)) strongly affected the physical properties of CH. The suspension of 1% (w/v) CNF treated with 4 h, 180 °C hydrothermal heating generated a CH with 99.3% water content, CNF with 87% crystallinity and an mechanical strength of 0.7 N breaking force.
Keywords: Squid pen; β-Chitin; Hydrothermal; Chitin nanofibrils; Hydrogels;
One-pot synthesis of chitosan-g-(PEO-PLLA-PEO) via “click” chemistry and “SET-NRC” reaction by Ke Zhang; Pengyu Zhuang; Zhengke Wang; Youliang Li; Zhiqiang Jiang; Qiaoling Hu; Minying Liu; Qingxiang Zhao (1515-1521).
► N-chitosan-g-(PEO-PLLA-PEO) graft copolymer was synthesized. ► “Click” and “SET-NRC” reactions were used to modify chitosan. ► The efficiencies of coupling reactions were greater than 90%. ► Graft ratio was 43% determined by the structure of 6-azide-N-phthaloyl-chitosan.For the development of biocompatible and degradable biomaterials, a kind of well-defined graft copolymer consisting of chitosan back-bone and amphiphilic PEO-PLLA-PEO branch chains was synthesized by Cu(0) catalyzed one-pot strategy combining “click” chemistry and single electron transfer-nitroxide radical coupling (SET-NRC) reaction. First, the precursors of 6-azide-N-phthaloyl-chitosan, TEMPO-PEO-alkyne and mPEO-PLLA-Br were designed and produced. Then, the one-pot coupling reactions between these precursors were performed in the presence of nanosized Cu and PMDETA. The efficiencies of the coupling reactions were greater than 90% determined by the FTIR and ESR spectra. The structure of graft copolymer with 43% of the grafting ratio was confirmed by the spectral analysis. This work provided a route to prepare chitosan graft copolymer.
Keywords: Chitosan; Graft modification; Amphiphilic copolymer; Click; SET-NRC;
Graft copolymerization of acrylic acid to cassava starch—Evaluation of the influences of process parameters by an experimental design method by J.R. Witono; I.W. Noordergraaf; H.J. Heeres; L.P.B.M. Janssen (1522-1529).
► Graft copolymerization of acrylic acid onto cassava starch with Fenton's initiator. ► Variables of relevance to copolymer synthesis were screened by experimental design. ► Temperature, starch concentration and its ratio to monomer are significant variables. ► Monomer conversion is always near 100% at all conditions.The graft copolymerization of cassava starch with acrylic acid was investigated using a free radical initiator system (Fe2+/H2O2 redox system) in water. A comprehensive understanding of the important variables and their interaction has been obtained by applying an experimental design method. In this approach, two (‘high’ and ‘low’) values of selected variables are considered. Important result parameters are add-on and the grafting efficiency. Out of eight reaction variables, it was found that only temperature, starch concentration and the starch to monomer ratio have a pronounced influence on these response parameters. Moderate reaction temperature (40 °C) and high starch concentration (10%) give relatively good results of add-on and grafting efficiency. A low starch to monomer ratio favors add-on but decreases grafting efficiency. These findings can be used to optimize the production of cassava starch–acrylate copolymers and to gain insight in the process–product property interactions, for various applications.
Keywords: Cassava starch; Experimental design approach; Grafting; Mathematical modeling; Copolymerization with acrylic acid;
The effect of NaCl on the rheological properties of suspension containing spray dried starch nanoparticles by Ai-min Shi; Dong Li; Li-jun Wang; Benu Adhikari (1530-1537).
► Rheological properties of spray dried starch nanoparticle suspensions were affected. ► NaCl was found to reduce viscosity of suspension containing starch nanoparticle. ► NaCl was found to restrain the gelling of suspension containing starch nanoparticle. ► NaCl was found to reduce the storage and loss moduli during frequency sweep. ► Addition of small amount of NaCl was found to lead to high creep-recovery.The effect of NaCl on the rheological properties of suspensions containing spray dried starch nanoparticles produced through high pressure homogenization and emulsion cross-linking technique was studied. Rheological properties such as continuous shear viscosity, viscoelasticity and creep-recovery were measured. NaCl (5–20%, w/w) was found to lower viscosity quite significantly (p < 0.05), enhance the heat stability and weaken their gelling behavior compared to starch-only suspension. NaCl reduced both the storage and loss moduli of suspension within the frequency range (0.1–10 rads/s) studied. However, NaCl brought higher speed of reduction on the storage modulus than on the loss modulus, which resulted into large increase in loss angle. The creep-recovery behavior of suspension was affected by NaCl and the recovery rate was highest (86%) at 15% NaCl. The Cross, the Power law and the Burger's models followed the experimental viscosity, storage and loss moduli, and creep-recovery data well with R 2 > 0.97.
Keywords: Rheological properties; Starch nanoparticles; Spray drying; NaCl; Suspension;
Rapid synthesis of antimicrobial paper under microwave irradiation by Samir kamel (1538-1542).
► AgNP containing paper was successfully prepared. ► The prepared antibacterial paper sheet has antibacterial effect against Candida, Staphyl., Pseudo. ► The UV–vis absorption spectrum exhibited absorption around 400–420 nm, confirming the formation of AgNP.The silver-nanoparticle (AgNP) containing paper was successfully prepared. The AgNP is deposited by the in situ reduction of silver nitrate on the acrylamide grafted bagasse paper sheets in the presence of citrate molecules as stabilizing agent. In the present paper, grafting of acrylamide onto bagasse paper sheets using potassium persulfate was carried out under the influence of microwave radiations (MWR). The modified paper sheets were characterized by Fourier transform infrared spectroscopy (FTIR), UV-spectroscopy, and scanning electron microscopy (SEM). Antimicrobial activities of the prepared paper sheets were also investigated against G+ve bacterium Staphylococcus aureus, G−ve bacterium Pseudomomas aeruginosa, and yeast Candida albicans, which are model microorganisms for testing bactericidal properties. The AgNP containing paper sheets exhibited antibacterial activity.
Keywords: Bagasse paper sheets; Grafting; Antimicrobial; Microwave radiation; Nanoparticle;
Synthesis, characterization and evaluation of thiolated tamarind seed polysaccharide as a mucoadhesive polymer by Harmanmeet Kaur; Shikha Yadav; Munish Ahuja; Neeraj Dilbaghi (1543-1549).
► Thiolation of TSP was done by esterification with thioglycolic acid. ► Polymer compacts of thiolated TSP exhibited 6.85-fold greater mucoadhesion than TSP. ► Carbopol-based metronidazole gels containing TSP and thiolated TSP were formulated. ► Gels containing TSP and thiolated TSP released the drug by first-order and Higuchi's-square root kinetics, respectively.In the present study, thiol-functionalization of tamarind seed polysaccharide was carried out by esterification with thioglycolic acid. Thiol-functionalization was confirmed by ―SH stretch in Fourier-transformed infra-red spectra at 2586 cm−1. It was found to possess 104.5 mM of thiol groups per gram. The results of differential scanning calorimetry and X-ray diffraction study indicate increase in crystallinity. Polymer compacts of thiolated tamarind seed polysaccharide required 6.85-fold greater force to detach from the mucin coated membrane than that of tamarind seed polysaccharide. Comparative evaluation of Carbopol-based metronidazole gels containing thiolated tamarind seed polysaccharide with gels containing tamarind seed polysaccharide for mucoadhesive strength using chicken ileum by modified balance method revealed higher mucoadhesion of gels containing thiolated tamarind seed polysaccharide. Further, the gels containing tamarind seed polysaccharide and thiolated tamarind seed polysaccharide released the drug by Fickian-diffusion following the first-order and Higuchi's-square root release kinetics, respectively.
Keywords: Tamarind seed polysaccharide; Thiolated tamarind seed polysaccharide; Metronidazole; Mucoadhesion;
Physical, chemical and mechanical properties of pehuen cellulosic husk and its pehuen-starch based composites by J. Castaño; S. Rodríguez-Llamazares; C. Carrasco; R. Bouza (1550-1556).
► Pehuen cellulosic husk was used as filler to prepare pehuen starch based composites. ► Husk has smooth and damage-free surface and it is decomposed above 325 °C. ► Thermal stability and mechanical properties of composites were improved. ► Pehuen-TPS/PLA/PVA composites showed microcracks at husk–matrix interface. ► There not were defects at husk/matrix interfaces pehuen-TPS composites.Pehuen cellulosic husk was characterized and employed as reinforcement for composite materials. In this research, thermoplastic pehuen starch (TPS) and TPS/poly(lactic acid) (PLA)/polyvinyl alcohol (PVA) composites, reinforced with 5 and 10% of pehuen husk, were prepared by melt-blending. Comparative samples of pehuen TPS and TPS/PLA/PVA blend were also studied. Physical, thermal, structural and mechanical properties of composites were evaluated.Pehuen husk mainly consists of cellulose (50 wt%), hemicellulose (30 wt%) and lignin (14 wt%). In respect to lipids, this husk has only a 0.6 wt%. Its surface is smooth and damage-free and it is decomposed above 325 °C.The incorporation of pehuen husk improved considerably the thermal stability and mechanical properties of the studied composites, mainly in TPS composites. Their thermal stability enhances since biofiber hinders the “out-diffusion” of volatile molecules from the polymer matrix, while mechanical properties could raise due to the natural affinity between husk and starch in the pehuen seed.
Keywords: Pehuen starch; Biofiber; Biodegradable; Composite;
One pot synthesis of polypyrrole silver nanocomposite on cotton fabrics for multifunctional property by K. Firoz Babu; P. Dhandapani; S. Maruthamuthu; M. Anbu Kulandainathan (1557-1563).
► Polypyrrole–silver nanocomposites were prepared on cotton fabrics by one pot synthesis. ► Silver incorporation onto the matrix of polymer was confirmed using XRD and XPS. ► Polymer nanocomposites showed higher conductivity. ► We observed excellent antimicrobial rate with the coated cotton fabrics.Polymer–silver nanocomposites modified cotton fabrics were prepared by in situ chemical oxidative polymerization using pyrrole and silver nitrate. In a redox reaction between pyrrole and silver nitrate, silver ions oxidize the pyrrole monomer and get reduced. This reduced silver as nanoparticles deposited on/into the polypyrrole/cotton matrix layer and the interaction between silver and polypyrrole was by adsorption or electrostatic interaction. The structure and composite formation on cotton fiber was investigated using SEM, FT-IR, XPS and XRD. The results showed that a strong interaction existing between silver nanoparticles with polypyrrole/cotton matrix. FT-IR studies clearly indicated that the interaction between polypyrrole (―N―H) and cellulose (>C―OH) was by hydrogen bonding. It is observed that the conductivity of the composite coated fabrics has been increased by the incorporation of silver nanoparticles. In the synthesized composites, silver content plays an important role in the conductivity and antimicrobial activity rate of the fabrics against gram positive Staphylococcus aureus and gram negative Escherichia coli bacteria.
Keywords: Conducting polymer; Silver nanoparticles; Composite; Conductive textiles; Antimicrobial activity;
Cereal β-glucan quantification with calcofluor-application to cell culture supernatants by Anne Rieder; Svein H. Knutsen; Simon Ballance; Stine Grimmer; Diego Airado-Rodríguez (1564-1572).
► The use of derivative signals of the calcofluor/β-glucan complex emission spectra improved calibration. ► A low detection limit of 0.045 μg/mL (Clayton criterion) was achieved. ► β-glucan quantification in special arabinoxylan samples correlated well with an enzyme based assay. ► An in vitro model with differentiated Caco-2 cells revealed transport of cereal β-glucan over intact cell layers.The specific binding of the fluorescent dye calcofluor to cereal β-glucan results in increased fluorescence intensity of the formed complex and is in use for the quantification of β-glucan above a critical molecular weight (MW) by flow injection analysis. In this study, this method was applied in a fast and easy batch mode. In order to emphasize the spectral information of the emission spectra of the calcofluor/β-glucan complexes, derivative signals were calculated. A linear relationship was found between the amplitude of the second derivative signals and the β-glucan concentration between 0.1 and 0.4 μg/mL. The low detection limit of this new method (0.045 μg/mL) enabled its use to study the transport of cereal β-glucans over differentiated Caco-2 cell monolayers. Additionally, the method was applied to quantify β-glucan in arabinoxylan samples, which correlated well with data by an enzyme based method.
Keywords: Cereal β-glucan; Calcofluor; Fluorescence spectroscopy; Cell culture; Uptake simulation;
Biomimetic growth of hydroxyapatite on phosphorylated electrospun cellulose nanofibers by Kaina Li; Jiangnan Wang; Xinqing Liu; Xiaopeng Xiong; Haiqing Liu (1573-1581).
► Electrospun cellulose nanofiber/hydroxyapatite composites were synthesized. ► Phosphorylated cellulose nanofibers were highly bioactive in inducing the HAp growth. ► The composites are porous materials with micro-, meso-pores and pores in micrometer. ► The composites can be potentially useful in the field of bone tissue engineering.In biomimicking the formation of collagen fiber/hydroxyapatite (HAp) in natural bone, electrospun cellulose nanofiber (CelluNF)/HAp composites were synthesized in simulated body fluid (SBF). Their morphology and structure were characterized by SEM, TEM, XRD and XPS. CelluNFs showed low bioactivity in inducing the growth of HAp. In order to improve this ability, CelluNFs were slightly phosphorylated with a degree of substitution of phosphate group of 0.28. The modified CelluNFs were highly effective in guiding the HAp growth along the fibers. The HAp crystal size in the composites was ca. 24 nm, and the lattice spacing of (2 1 1) plane was 2.83 Å. It was found that the HAps in the composites were calcium deficient. The CelluNF/HAp composites are highly porous materials with micro-, meso-, and macro-pores. A mechanism for the HAp growth on CelluNFs was presented. Such CelluNF/HAp composites can be potentially useful in the field of bone tissue engineering.
Keywords: Electrospinning; Nanofiber; Hydroxyapatite; Cellulose biocomposite;
Electric field induced phase separation on electrospinning polyelectrolyte based core–shell nanofibers by Xueyan Mu; Yang Liu; Dawei Fang; Zhiliang Wang; Jun Nie; Guiping Ma (1582-1586).
► Polyelectrolyte based core–shell nanofibers were prepared via electrospinning. ► Electric field effected the formation of core–shell fibers. ► The core–shell nanofibers have potential applications in biomedical field.In the present study, we report a facile method to fabricate polyelectrolyte based core–shell nanofibers with the assistance of the high gradient electric potential between the tip of capillary and the collector. The core–shell structure and the composition of each layer have been supported by TEM and XPS studies. The effect of the electric field on the phase separation was considered to be the major factor. An electric field experiment was introduced to elucidate the influence of electric field on the phase separation process. It was assumed the polyelectrolyte based core–shell nanofibers membrane could be applied in wound care and tissue engineering.
Keywords: Electrospinning; Core–shell; Electric field; Polyelectrolyte;
Preparation and characterization of gelatinized granular starches from aqueous ethanol treatments by Benshan Zhang; Sushil Dhital; Enamul Haque; Michael J. Gidley (1587-1594).
► Gelatinized granular forms of starch prepared from five starch types. ► Evaporation of ethanol/water mixtures used to control gelatinization. ► Starch surfaces responded differently to solvent treatment. ► Amylose confirmed as important for gelatinized granule integrity.In order to modify the properties of native starch granules, the formation of gelatinized granular forms (GGS) from normal, waxy, and high amylose maize, as well as potato and tapioca starches was investigated by treating granules with aqueous ethanol at varying starch:water:ethanol ratios and then heating in a rotary evaporator to remove ethanol. The modified starches were characterized using bright field, polarized and electron microscopy. Short/long range molecular order and enthalpic transitions on heating were also studied using infrared spectroscopy, X-ray diffractometry and differential scanning calorimetry respectively. A diffuse birefringence pattern without Maltese cross was observed for most GGS samples. Treatment with aqueous ethanol resulted in starch-specific changes in the surface of granules, most noticeably swelling and disintegration in waxy maize, surface wrinkling in normal maize and tapioca, swelling and opening-up in potato starches, and swelling and bursting in high amylose maize. The ratio of ethanol to water at which original granular order was disrupted also varied with starch type. GGS had less short range molecular order than native granules as inferred by comparing 1047/1022 wave number ratio from infrared spectroscopy. Similarly, A- and B-type diffraction reflections were either reduced or completely lost with evolution of V-type patterns in GGS.
Keywords: Gelatinized granular starches; Cold water solubility; Aqueous ethanol treatment; V-type crystallinity;
Effect of gelatinization and additives on morphology and thermal behavior of corn starch/PVA blend films by Xuegang Luo; Jiwei Li; Xiaoyan Lin (1595-1600).
► Starch/polyvinyl alcohol blend films were prepared by the solution casting method. ► The effects of gelatinization on the properties of the films were investigated. ► The effects of additives on the properties of the films were investigated. ► A conceptual model of hydrogen bonding interactions was established.The blend films of ungelatinized and gelatinized starch/polyvinyl alcohol (PVA) were prepared with a solution casting method by the introduction of additives (glycerol/urea) or not. The phase morphologies and thermal behaviors of the blends were carefully analyzed. A droplet phase was observed in the blends containing ungelatinized starch and a laminated phase was observed in the blends containing gelatinized starch. For both ungelatinized and gelatinized starch/PVA blends, the melting temperature (T m) (210–230 °C) of PVA was detected, and the T m of gelatinized starch/PVA blends was higher than that of the ungelatinized starch/PVA blends. Blend films containing 16.8 wt% of glycerol or urea exhibited a decreased T m. The introduction of additives (glycerol or urea) reduced the decomposition onset temperature of the blend films. These various morphologies and thermal behaviors could be attributed to the different hydrogen bonding interaction characteristics between starch and polyvinyl alcohol at different conditions.
Keywords: Polyvinyl alcohol; Starch; Gelatinization; Additive; Morphology; Thermal behavior;
Mechanical and barrier properties of nanocrystalline cellulose reinforced chitosan based nanocomposite films by Avik Khan; Ruhul A. Khan; Stephane Salmieri; Canh Le Tien; Bernard Riedl; Jean Bouchard; Gregory Chauve; Victor Tan; Musa R. Kamal; Monique Lacroix (1601-1608).
► NCC reinforced chitosan-based films were prepared by casting. ► Incorporation of only 5% (w/w) NCC improved the TS of the chitosan films by 24%. ► Favorable NCC–chitosan interaction and effective stress transfer. ► NCC incorporation enhanced the barrier properties of the films. ► SEM images revealed proper dispersion of NCC into chitosan matrix.Nanocrystalline cellulose (NCC) reinforced chitosan-based biodegradable films were prepared by solution casting. The NCC content in the films was varied from 1 to 10% (dry wt. basis). It was found that the tensile strength (TS) of the nanocomposite films with 5% (w/w) NCC content was optimum with an improvement of 26% compared to the control chitosan films. Incorporation of NCC also significantly improved barrier properties. Water vapor permeability (WVP) of the chitosan/NCC films was decreased by 27% for the optimum 5% (w/w) NCC content. Swelling studies revealed a decrease in water uptake of the NCC-reinforced chitosan films. Analyses of thermal properties showed no significant effect of NCC whereas X-ray diffraction studies confirmed the appearance of crystalline peaks in the nanocomposite films. Surface morphology of the films was investigated by scanning electron microscopy and it was found that NCC was dispersed homogenously into chitosan matrix.
Keywords: Chitosan; Nanocrystalline cellulose; Biodegradable; Nanocomposite films; Mechanical properties; Barrier properties;
Homogeneous isolation of nanocellulose from sugarcane bagasse by high pressure homogenization by Jihua Li; Xiaoyi Wei; Qinghuang Wang; Jiacui Chen; Gang Chang; Lingxue Kong; Junbo Su; Yuhuan Liu (1609-1613).
► Nanocellulose was isolated by homogeneous high pressure homogenization process. ► It was with 10–20 nm in diameter and low crystallinity. ► The study is effective in high recovery of cellulose and recycled stratagem. ► It promotes chances for potential applications in the near future.Nanocellulose from sugarcane bagasse was isolated by high pressure homogenization in a homogeneous media. Pretreatment with an ionic liquid (1-butyl-3-methylimidazolium chloride ([Bmim]Cl)) was initially involved to dissolve the bagasse cellulose. Subsequently, the homogeneous solution was passed through a high pressure homogenizer without any clogging. The nanocellulose was obtained at 80 MPa for 30 cycles with recovery of 90% under the optimum refining condition. Nanocellulose had been characterized by Fourier transformed infrared spectra, X-ray diffraction, thermogravimetric analysis, rheological measurements and transmission electron microscopy. The results showed that nanocellulose was 10–20 nm in diameter, and presented lower thermal stability and crystallinity than the original cellulose. The developed nanocellulose would be a very versatile renewable material.
Keywords: Nanocellulose; Homogeneous; High pressure homogenization; Sugarcane bagasse;
Preparation, characterization and properties of aminoethyl chitin hydrogels by Guanghua He; Zi Wang; Hua Zheng; Yihua Yin; Xiong Xiong; Rongye Lin (1614-1619).
► The aminoethyl chitin (AEC) hydrogels were prepared by crosslinking with glutaraldehyde. ► The hydrogels were pH sensitive to acidic environment. ► The swelling properties of the hydrogels were affected by the amino content of AEC, etc. ► The hydrogels exhibited good antibacterial activities.Aminoethyl chitins (AEC) with different amino contents were synthesized from chitin and 2-chlorethylamine hydrochloride, and the AEC hydrogels were prepared by crosslinking with glutaraldehyde. The microstructures, swelling behaviors and antibacterial activities of the hydrogels were investigated. The results of Fourier transform infrared spectroscopy (FTIR), 1H nuclear magnetic resonance (1H NMR) spectrum and scanning electron microscopy (SEM) showed that the hydrogels were prepared by forming the Schiff base from AEC and glutaraldehyde. The aminoethyl chitin hydrogels were sensitive to acidic environment. The swelling ratio changed with the amino content of AEC, declined with the increase of the crosslinking agent concentration and increased with the increase of the AEC concentration. In addition, the antibacterial results of the hydrogels against Staphylococcus aureus (S. aureus) indicated that the hydrogels had good antibacterial activities, and the antibacterial properties were affected by the amino content of AEC and the crosslinking agent concentration.
Keywords: Chitin; Aminoethyl chitin; Hydrogel; Swelling property; Antibacterial activity;
‘Green’ crosslinking of native starches with malonic acid and their properties by Trina Ghosh Dastidar; Anil N. Netravali (1620-1628).
► ‘Green’, non-toxic, water based crosslinking of native starches. ► Plant based, sustainable polycarboxylic acid (malonic acid) as crosslinker. ► Confirmation of successful crosslinking of starches using various techniques. ► Potato starch is found to be more reactive than corn starch. ► Higher mechanical properties and decrease in hydrophilicity after crosslinking.Starch is a highly hydrophilic biomaterial with weak mechanical properties rendering it useless for commercial applications. A fully ‘green’ water based process is presented to crosslink corn (cereal) and potato (tuber) starch to enhance mechanical properties as well as lower hydrophilicity. In addition, malonic acid, a green, plant based water soluble and relatively inexpensive polycarboxylic acid, was used as the crosslinker. The reactivity of potato starch toward esterification and crosslinking was found to be higher than that of corn starch owing to the inherent differences in the granule morphology and internal structure of the two starches. It was observed that potato starch granules had a higher degree of substitution (DS) of 0.19 than corn starch granules (DS = 0.1) under similar reaction conditions. Chemical, thermal and mechanical test results confirmed the crosslinking as well as reduced moisture sensitivity.
Keywords: Starch resins; Green crosslinking; Esterification; Moisture sensitivity; Mechanical properties;
Radiation effects on microcrystalline cellulose in 1-butyl-3-methylimidazolium chloride ionic liquid by Yan Hao; Jing Peng; Yinyong Ao; Jiuqiang Li; Maolin Zhai (1629-1633).
► A new and convenient method to control average molecular weight of cellulose. ► Radiation degradation of MCC in ionic liquid was first studied by viscometry. ► The radiation degradation of MCC in [Bmim]Cl is attributed to numerous radicals. ► The content of MCC in [Bmim]Cl has negligible effect on degradation of cellulose. ► DMSO can efficiently inhibit the radiation degradation of cellulose in [Bmim]Cl.The radiation processing of cellulose in ionic liquids (ILs) demands a comprehensive knowledge of radiation effects on cellulose in ILs. Herein, gamma radiation-induced degradation kinetics of microcrystalline cellulose (MCC) in 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) was studied by viscometry. The intrinsic viscosity of MCC in [Bmim]Cl decreased slightly with increasing dose; while chemical structure and crystalline state of cellulose has no obvious change up to 300 kGy. The radiation degradation rate constant (k) of MCC in [Bmim]Cl was 2.60 × 10−7/kGy, lower than that of solid cellulose, but higher than that in N-methylmorpholine-N-oxide (NMMO) solvent. Furthermore, k value decreased to 1.12 × 10−7/kGy in dimethyl sulfoxide (DMSO)/[Bmim]Cl system due to the free radicals scavenging of DMSO. The radicals generated during irradiation play main role in the radiation degradation of MCC in [Bmim]Cl. This work provides a new way to control the average molecular weight of cellulose by radiation-induced degradation of cellulose in ILs.
Keywords: γ-Ray irradiation; Radiation degradation kinetic; Microcrystalline cellulose; Ionic liquids; N-Methylmorpholine-N-oxide;
Preparation of pH- and ionic-strength responsive biodegradable fumaric acid crosslinked carboxymethyl cellulose by Emine Akar; Aylin Altınışık; Yoldaş Seki (1634-1641).
► A novel biodegradable sodium carboxymethyl cellulose-based hydrogel was synthesized by using fumaric acid (FA) as a crosslinking agent. ► Hydrogels show pH- and ionic-strength responsive behavior. ► Reversible pH-responsiveness of hydrogels was observed. ► Hydrogels exhibited biodegradable property.A novel biodegradable sodium carboxymethyl cellulose (NaCMC)-based hydrogel was synthesized by using fumaric acid (FA) as a crosslinking agent at various ratios. Hydrogels (CMCF) were characterized using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). Swelling behaviors of hydrogels were investigated in distilled water, various salt, and pH solutions. The FTIR results indicated the crosslinking between carboxyl groups of FA with hydroxyl group of NaCMC through ester formation. AFM analyses showed that roughness of hydrogel surface decreased with increasing crosslinker concentration. The swelling capacity decreased with an increase in charge of the metal cation (Al3+ < Ca2+ < Na+). In order to investigate reversible pH sensitivity of CMCF hydrogels, pH-dependent swelling was studied at pH 2 and 10. Reversible pH-responsiveness of CMCF hydrogels was achieved. CMCF hydrogels containing the greatest ratio of FA exhibited the longest biodegradation time with a half life of 21 h using cellulase.
Keywords: Carboxymethylcellulose; pH-responsive; Biodegradability; Fumaric acid; Hydrogel;
Characterization and anti-allergic effect of a polysaccharide from the flower buds of Lonicera japonica by Jing Tian; Huilian Che; Da Ha; Yeping Wei; Shuyun Zheng (1642-1647).
► A polysaccharide (LJP-1) was isolated from Lonicera japonica and partially characterized. ► Oral administration of LJP-1 could inhibit ear thickness induced by picryl chloride (PC). ► LJP-1 treatment leads to substantial reductions in serum IgE, serum histamine and tissue TNF-α level. ► Treatment with LJP-1 may be effective for allergic contact dermatitis.A water-soluble polysaccharide (LJP-1), with a molecular weight of 1.8 × 105 Da, was isolated from the flower buds of Lonicera japonica. Gas chromatography (GC) analysis showed that the LJP-1 was mainly composed of d-glucose and a small amount of d-arabinose. On the basis of methylation analysis, LJP-1 had the backbone chain mainly consisting of 1,6-linked Glc and 1,3,6-linked Glc, which was terminated with 1-linked Ara residues at the O-3 position of 1,3,6-linked Glc in a relative molar ratio of 2.9:1:0.9. The anti-allergic effect of LJP-1 was evaluated on allergic contact dermatitis (ACD) induced by picryl chloride (PC) in mouse ear. Similar to prednisolone, orally administrated LJP-1 (20, 40 and 80 mg/kg) potently inhibited the PC-induced ACD, leading to substantial reductions in ear thickness, serum level of IgE and histamine, as well as tissue TNF-α. These results demonstrate that treatment with LJP-1 may be effective for preventing the development of PC-induced ACD.
Keywords: Lonicera japonica; Polysaccharide; Characterization; Anti-allergic effect; Allergic contact dermatitis;
Chitosan matrix with three dimensionally ordered macroporous structure for nimodipine release by Yuling Xie; Yanli Liu; Yan Wang; Siling Wang; Tongying Jiang (1648-1655).
► 3DOM chitosan matrix with interconnected macropores in the nanometer range was prepared using a template-assisted assembly. ► Combination with silica supported the polymer network effectively. ► It is a novel matrix-delivery drug system. ► Effects of matrix particle size, drug loadings and dissolution medium at different pH values on drug release were investigated.Three dimensionally ordered macroporous (3DOM) chitosan (3D-CS) matrix with interconnected pores in the nanometer range was developed as a drug carrier for the first time. 3D-CS was prepared using a template-assisted assembly and characterized by SEM, TGA, N2 adsorption and FT-IR. As a model drug, nimodipine (NMDP) was incorporated into the pores of 3D-CS matrix. The solid state properties of NMDP-loaded samples were characterized by SEM, XRD, DSC and FT-IR. Dissolution studies showed that release behavior of the drug was markedly affected by the particle size of the matrix. With a relatively small matrix particle size, formulations of NMDP-3D-CS-0.5 and NMDP-3D-CS-1 exhibited rapid release patterns. However, on increasing the amount of carrier, release rate of the drug decreased. The pH-dependent slow-release characteristic of 3D-CS matrix delivery system was demonstrated by investigating the release behavior of NMDP at different pH values.
Keywords: 3DOM; Chitosan; Nanometer range; Release behavior;
LBL structured chitosan-layered silicate intercalated composites based fibrous mats for protein delivery by Wei Li; Ruifen Xu; Liangqun Zheng; Jing Du; Yuli Zhu; Rong Huang; Hongbing Deng (1656-1663).
► BSA and CS–OREC composites were LBL immobilized on fibrous mats. ► OREC introduction enlarged the average diameter of LBL films coating. ► CS–OREC intercalated structure could enhance the protein loading capacity. ► Doubling the coating bilayers could improve the BSA loading capacity. ► OREC could affect the protein release properties of LBL films coating.Organic rectorite (OREC) was used to prepare intercalated composites with chitosan. The negatively charged cellulose acetate (CA) fibrous mats were modified with multilayers of the positively charged chitosan or chitosan–OREC intercalated composites and the negatively charged bovine serum albumin (BSA) via electrostatic layer-by-layer (LBL) self-assembly technique. The morphology and protein delivery properties of the resultant samples were investigated by regulating the number of deposition bilayers, the outermost layer and the composition of coating bilayers. The thickness of LBL films coated CA mats increased as the number of bilayers was increased and OREC was added. X-ray photoelectron spectroscopy indicated that chitosan and OREC were deposited on CA fibers. Small angle X-ray diffraction patterns showed that OREC was intercalated by chitosan. The in vitro BSA encapsulation and release experiments demonstrated that OREC could affect the degree of protein loading capacity and release efficiency of the LBL films coating.
Keywords: Chitosan; Organic rectorite; LBL; Fibrous mats; Protein delivery;
Antioxidant and antihyperlipidemic activities of polysaccharides from sea cucumber Apostichopus japonicus by Xin Liu; Zhenliang Sun; Miansong Zhang; Xiumei Meng; Xuekui Xia; Wenpeng Yuan; Feng Xue; Changheng Liu (1664-1670).
► Polysaccharide was prepared from Apostichopus japonicus by enzymolysis method. ► It showed potent free radical scavenging activities in vitro. ► It also exerted antihyperlipidemic effect in high-fat diet-induced rats.Polysaccharides (AJP) were prepared from Apostichopus japonicus by protease hydrolysis method. Antioxidant activity in vitro and antihyperlipidemic activity in vivo was investigated. Chemical composition analysis indicated that AJP was mainly composed of glucosamine, galactosamine, glucuronic acid, mannose, glucose, galactose and fucose, with an average molecular weight of about 36.2 kDa. The antioxidant capacities of AJP were, respectively, evaluated by the assays of scavenging DPPH, hydroxyl and superoxide radicals, and reducing power in vitro. It showed potent free radical scavenging activities and reducing power. Serum total cholesterol (TC), triglyceride (TG) and low-density lipoprotein (LDL-C) decreased significantly and high-density lipoprotein cholesterol (HDL-C) increased significantly after treatment of hyperlipidemic Wistar rats with AJP. These results suggest that AJP may prove to be a potential candidate of the natural antioxidants as a therapeutic agent for hyperlipidemia.
Keywords: Apostichopus japonicus; Polysaccharide; Antioxidant activity; Antihyperlipidemic activity;
Purification and antitumor activity of two acidic polysaccharides from the roots of Polygala tenuifolia by Tao Xin; Fubin Zhang; Qiuying Jiang; Chunhong Chen; Dayong Huang; Yanju Lv; Weixi Shen; Yinghua Jin (1671-1676).
► Two acidic polysaccharide was isolated from the roots of Polygala tenuifolia. ► They significantly inhibited the growth of A549 cells in vitro. ► They exhibited significant antitumor activity against lung cancer A549 in vivo. ► The antioxidant status in A549-bearing mice was improved by polysaccharides. ► They may be useful for the prevention of lung tumorigenesis.Two acidic polysaccharide fractions (PTPa and PTPb) extracted from the roots of Polygala tenuifolia, were obtained by DEAE-Sephacel anion-exchange, and Sephadex G-100 gel-permeation chromatography. High-performance liquid chromatography (HPLC) identified that PTPa and PTPb was composed of Ara, Glc, Gal, Man and GlcUA in the proportion of 2.4:1.2:0.6:0.4:1.1 and 2.1:1.7:0.5:0.6:1.7, respectively. Their molecular weight was evaluated to be 5.9 × 104 (PTPa) and 2.5 × 104 Da (PTPb) as determined by high performance size exclusion chromatography (HPSEC). Pharmacological studies revealed PTPa and PTPb significantly inhibited the growth of A549 cells in vitro and exhibited significantly higher antitumor activity against solid tumor A549 in vivo than did a blank control. Moreover, treatment with two acidic polysaccharides caused an enhancement of superoxide dismutase (SOD) and catalase (CAT) activities in tumor-bearing mice and a reduction in thiobarbituric acid reactive substances (TBARS) level. Taken together, these results indicated that two acidic polysaccharides from the roots of P. tenuifolia may be useful as potent antitumor agents for the prevention of lung tumorigenesis.
Keywords: Polygala tenuifolia; Polysaccharide; Antioxidative; Antitumor; Human lung adenocarcinoma A549;
The plasticizing mechanism and effect of calcium chloride on starch/poly(vinyl alcohol) films by Xiancai Jiang; Ting Jiang; Lingling Gan; Xiaofei Zhang; Hua Dai; Xi Zhang (1677-1684).
► CaCl2 could form strong interaction with starch and PVA molecules. ► The miscibility of starch and PVA was improved with the addition of CaCl2. ► CaCl2 could destroy the crystals of starch/PVA film. ► T g and the thermal stability of starch/PVA film decreased. ► CaCl2 could effectively improve the mechanical property of starch/PVA film.Starch/poly(vinyl alcohol) (PVA) films were prepared with calcium chloride (CaCl2) as the plasticizer. The micro morphology of pure starch/PVA film and CaCl2 plasticized starch/PVA film was observed by scanning electron microscope. The interaction between CaCl2 and starch/PVA molecules was investigated by Fourier transform infrared spectroscopy. The influence of CaCl2 on the crystalline, thermal and mechanical properties of starch/PVA films was studied by X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, and tensile testing, respectively. The results indicated that CaCl2 could interact with starch and PVA molecules and then effectively destroy the crystals of starch and PVA. Starch/PVA films plasticized with CaCl2 became soft and ductile, with lower tensile strength and higher elongation at break compared with pure starch/PVA film. The water content of starch/PVA film would increase with the addition of CaCl2. This is an important cause of the plasticization of CaCl2 on starch/PVA film.
Keywords: Starch; Poly(vinyl alcohol); Blend; Film; Calcium chloride;
Irradiation depolymerized guar gum as partial replacement of gum Arabic for microencapsulation of mint oil by Shatabhisa Sarkar; Sumit Gupta; Prasad S. Variyar; Arun Sharma; Rekha S. Singhal (1685-1694).
► Gamma-radiation depolymerized guar gum in combination with gum Arabic was used as wall material for encapsulation of mint oil. ► Depolymerized guar gum based wall material resulted in better retention of mint oil. ► PCA showed better retention of compounds like menthol and isomenthol in guar gum microcapsules.Spray dried microcapsules of mint oil were prepared using gum Arabic alone and its blends with radiation or enzymatically depolymerized guar gum as wall materials. Microcapsules were evaluated for retention of mint oil during 8-week storage during which qualitative changes in encapsulated mint oil was monitored using principal component analysis. The microcapsules with radiation depolymerized guar gum as wall material component could better retain major mint oil compounds such as menthol and isomenthol. The t 1/2 calculated for mint oil in microcapsules of gum Arabic, gum Arabic:radiation depolymerized guar gum (90:10), gum Arabic:enzyme depolymerized guar gum (90:10) was 25.66, 38.50, and 17.11 weeks, respectively. The results suggested a combination of radiation depolymerized guar gum and gum Arabic to show better retention of encapsulated flavour than gum Arabic alone as wall material.
Keywords: Guar gum; Irradiation; Mint oil; Microencapsulation; Storage stability;
Comparative study of vascular prostheses coated with polycyclodextrins for controlled ciprofloxacin release by N. Blanchemain; Y. Karrout; N. Tabary; M. Bria; C. Neut; H.F. Hildebrand; J. Siepmann; B. Martel (1695-1703).
► Polyester vascular graft was modified with a cyclodextrin polymer (βCD, HPβCD, MeβCD). ► The inclusion of ciprofloxacin in the three cyclodextrins was proved by NMR. ► The drug loading and drug release depends on the kind of chose cyclodextrin. ► The antibacterial activity is prolonged at least 24 h on Escherichia coli and Staphylococcus aureus.A textile polyester vascular graft was modified with cyclodextrins to obtain a new implant capable of releasing antibiotics (here ciprofloxacin, CFX) over prolonged time periods and thereby reducing the risk of post-operative infections. In this study, we compared samples modified with native and modified cyclodextrins, presenting different cavity sizes (β or γ cyclodextrins) and different substituent groups (hydroxypropyl and methyl). Drug release was measured in water, phosphate buffer pH 7.4 and blood plasma. The inclusion of CFX in the cyclodextrins cavities was observed in solution by two-dimensional 1H NMR spectroscopy and confirmed by 1F NMR measurements. Grafts modification with all cyclodextrins induced an increase of their sorption capacity towards CFX whose extent depended on the nature of the cyclodextrin: a 4-fold and 10-fold increase was observed in the cases of hydroxypropyl cyclodextrins and methylated β-cyclodextrin, respectively. Depending on the type of release medium and nature of CD, different CFX release kinetics were obtained. The discussion highlighted not only the role of the host guest complexation, but also that of the electrostatic interactions that occur between the anionic crosslinks of the cyclodextrins polymers, and CFX that presents a zwitterionic character. The microbiological assessment confirmed sustained CFX release in human plasma and demonstrated antibacterial efficiency of CD modified prostheses against Staphylococcus aureus and Escherichia coli for at least 24 h (compared to 4 h in the case of virgin grafts).
Keywords: Polyester vascular prosthesis; Cyclodextrins; Drug complexation; Ciprofloxacin; Drug release; Antimicrobial activity;
Reductive alkylation of hyaluronic acid for the synthesis of biocompatible hydrogels by click chemistry by Gloria Huerta-Angeles; Miroslava Němcová; Eva Příkopová; Daniela Šmejkalová; Martin Pravda; Lukáš Kučera; Vladimír Velebný (1704-1711).
► Oxidation followed by reductive amination of hyaluronic acid. ► Non toxic catalyst 4-Ac-TEMPO and picoline borane used for the reaction. ► Easy scale-up and negligible degradation of the polysaccharide. ► Successful scaffold synthesis from N-alkylated derivates applying click chemistry.Hyaluronan (HA) based hydrogels have been synthesized combining chemical modification of the polysaccharide by partial oxidation, reductive amination and ‘click chemistry’. HA was oxidized by 4-acetamido-TEMPO-mediated reaction, using sodium hypochlorite as primary oxidant and NaBr in buffered pH, so that the produced aldehyde moieties (hemiacetals) were trapped in situ by adding primary amines containing azide or alkyne-terminal groups. The structure of the reaction products, oxidized-HA and primary amines bonded to HA, was elucidated using 2D NMR spectroscopy. SEC-MALLS analysis of the modified substrates showed a negligible degradation of the polysaccharide using this procedure. Furthermore, azido- and alkynyl derivatives underwent cross-linking by click chemistry into hydrogels, which were characterized by NMR, FT-IR, swelling degree and mechanical properties. Possible application of the material as scaffold for tissue engineering was tested by seeding and proliferation of chondrocytes for up to 15 days.
Keywords: Hyaluronic acid; 4-Ac-TEMPO-mediated oxidation; Reductive alkylation; Click chemistry;
The removal of stickies with modified starch and chitosan—Highly cationic and hydrophobic types compared with unmodified ones by Gudrun Petzold; Katrin Petzold-Welcke; Haisong Qi; Knut Stengel; Simona Schwarz; Thomas Heinze (1712-1718).
► We investigate the interaction of starch with a sticky containing model suspension. ► Polyelectrolyte complexes between cationic starch and model suspension are formed. ► The surface activity in suspension is characterized using dynamic interface tension. ► We can obtain additional information on the sticky content of the wastewater.The removal of dissolved and colloidal substances (DCS) in paper cycling water, so called stickies, with tailored natural polymers, having cationic as well as hydrophobic groups, was investigated using model suspensions made by the recycling of paper. The sticky content, characterized by the turbidity, the anionic charge, and the total organic carbon content (TOC) was increased by the addition of latex. The dynamic surface tension was established as useful tool for the characterization of the sticky content.The sticky removal using the starch derivatives (with benzyl- as well as ethyl-substituents), from very low up to high cationic charge and N-(benzyl)chitosan was compared. Depending on the properties of the derivatives two possible mechanisms can be found: “charge dominated removal” or “removal dominated by hydrophobicity.” It seems that turbidity and TOC are lowered especially due to charge interaction whereas the increase of the surface tension is mainly caused by the hydrophobic character of the modified natural polymers.
Keywords: Starch; Chitosan; Stickies; Complex formation; Polycation; Hydrophobicity;
Investigation of inclusion complex of cilnidipine with hydroxypropyl-β-cyclodextrin by Liandong Hu; Hailei Zhang; Weihua Song; Deliang Gu; Qiaofeng Hu (1719-1724).
► We prepared cilnidipine-HP-β-CD inclusion complex for the first time. ► The results of DSC, PXRD, FT-IR and 1H NMR all proved the formation of cilnidipine-HP-β-CD inclusion complex. ► The solubility of cilnidipine was increased for more than 10,000-fold in the presence of HP-β-CD. ► The dissolution rates and photostability of cilnidipine were also improved through complexation technique.The objective of this study was to improve the water-solubility and photostability of cilnidipine by complexing it with hydroxypropyl-β-cyclodextrin (HP-β-CD or HP-beta-CD). The interactions of cilnidipine and HP-β-CD were characterized by ultra violet–visible (UV/VIS) spectroscopy, differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), Fourier transformation-infrared (FT-IR) spectroscopy and 1H nuclear magnetic resonance (1H NMR) spectroscopy to verify the formation of cilnidipine-HP-β-CD complex inclusion. Moreover, the binding sites in the HP-β-CD structure were also tracked through 1H NMR spectroscopy analysis. All the characterization information proved the formation of cilnidipine-HP-β-CD inclusion complex, and the results demonstrated the superiority of the inclusion complex in dissolution rates and photostability; in addition, the apparent solubility of cilnidipine was increased more than 10,000-fold in the presence of HP-β-CD. The stability constant (1:1) was found to be 50,116 M−1, suggesting a high tendency of the drug to enter the HP-β-CD cavity. These results identified the cilnidipine-HP-β-CD inclusion complex as an effective new approach to design a novel formulation for pharmaceutical application.
Keywords: Inclusion complex; Cilnidipine; HP-β-CD; Characterization; Photostability;
Design of deformable chitosan microspheres loaded with superparamagnetic iron oxide nanoparticles for embolotherapy detectable by magnetic resonance imaging by Eun-Young Chung; Hyeong-Min Kim; Ga-Hyeon Lee; Byung-Kook Kwak; Ji-Sung Jung; Hyo-Jeong Kuh; Jaehwi Lee (1725-1731).
► Ionotropic gelation and genipin crosslinking yielded chitosan microbeads with SPIO. ► Release of SPIO from chitosan micromatrices increased in PBS with lysozyme. ► In vitro phantom study determined suitable SPIO concentrations for in vivo study. ► Retention of embolized chitosan microspheres could be monitored for 18 weeks.The purpose of this study was to design chitosan microspheres (MS) loaded with superparamagnetic iron oxide nanoparticles (SPIO) suitable for anti-cancer embolotherapy detectable by MRI. Deformable chitosan MS loaded with varying SPIO concentrations (SPIO-chitosan MS) were prepared by ionotropic gelation and a porogenic technique using polyethylene glycol, followed by genipin crosslinking. Adding SPIO nanoparticles to chitosan MS did not significantly affect the chitosan MS morphology. An in vitro phantom study led to selecting SPIO-chitosan MS prepared with 1.0 mM SPIO for an in vivo MR traceability study. SPIO-chitosan MS could be identified following embolization in the renal artery by MRI at 18 weeks. Histological and pathological evidence also showed that SPIO-chitosan MS blocked and remained in the target vessels. Therefore, deformable SPIO-chitosan MS is MR-detectable embolic material with a possible application for anti-cancer embolotherapy.
Keywords: Deformable chitosan microsphere; Superparamagnetic iron oxide; Anti-cancer embolization; Magnetic resonance imaging; Traceability;
Rheological properties of suspensions containing cross-linked starch nanoparticles prepared by spray and vacuum freeze drying methods by Ai-min Shi; Dong Li; Li-jun Wang; Benu Adhikari (1732-1738).
► Starch nanoparticles were produced through spray drying and vacuum freeze drying. ► Rheological behavior of suspensions containing these two types StNPs was investigated. ► Suspensions contain spray dried StNPs showed lower viscosity within shear range tested. ► Suspensions contain freeze dried StNPs showed stronger shear thinning and thixotropic. ► Suspensions containing freeze dried starch StNPs showed stronger elastic structure.The rheological behavior of suspensions containing vacuum freeze dried and spray dried starch nanoparticles was investigated to explore the effect of these two drying methods in producing starch nanoparticles which were synthesized using high pressure homogenization and mini-emulsion cross-linking technique. Suspensions containing 10% (w/w) spray dried and vacuum freeze dried nanoparticles were prepared. The continuous shear viscosity tests, temperature sweep tests, the frequency sweep and creep-recovery tests were carried out, respectively. The suspensions containing vacuum freeze dried nanoparticles showed higher apparent viscosity within shear rate range (0.1–100 s−1) and temperature range (25–90 °C). The suspensions containing vacuum freeze dried nanoparticles were found to have more shear thinning and less thixotropic behavior compared to those containing spray dried nanoparticles. In addition, the suspensions containing vacuum freeze dried particles had stronger elastic structure. However, the suspensions containing spray dried nanoparticles had more stiffness and greater tendency to recover from the deformation.
Keywords: Rheological behavior; Starch nanoparticles; Spray drying; Vacuum freeze drying; Suspensions;
Protective effect of a polysaccharide from stem of Codonopsis pilosula against renal ischemia/reperfusion injury in rats by Zhanting Li; Libing Zhu; Han Zhang; Jie Yang; Jie Zhao; Dewei Du; Junping Meng; Feng Yang; Yanlong Zhao; Jifeng Sun (1739-1743).
► Codonopsis pilosula has been long used for treatment of various ischemic events. ► We purified a polysaccharide (S-CPPA1) from the stem of C. pilosula. ► S-CPPA1 is a branched polysaccharide, with five glucosidic linkage forms. ► S-CPPA1 exerts a protective effect on ischemia/reperfusion induced renal injury. ► Renoprotective effect is probably mediated by inhibiting TNF-α release.In this study, we purified a homogeneous polysaccharide (S-CPPA1) with a molecular weight (Mw) of 133.2 kDa from the stem of Codonopsis pilosula for the first time. Gas chromatography (GC) analysis identified that S-CPPA1 contained glucose, galactose, and arabinose with a molar ratio of 10.5:3.4:1.7, along with a trace of mannose. Methylation analysis suggested S-CPPA1 was a branched polysaccharide, with five glucosidic linkage forms, namely (1→4)-linked Glcp (residue A), (1→6)-linked Galp (residue B), (1→2,6)-linked Glcp (residue C), (1→5)-linked Araf (residue D), and non-reducing terminal (1→)-linked Glcp (residue E). The protective effect of S-CPPA1 on kidney ischemia/reperfusion (I/R) injury was also evaluated. Blood urea nitrogen (BUN), creatinine and TNF-α levels, as well as lactate dehydrogenase (LDH) and alanine transaminase (AST) activities were elevated in the I/R group as compared to the sham group. On the other hand, S-CPPA1 treatment reversed all these biochemical indices, as well as histopathological alterations, which were induced by I/R. The findings imply that S-CPPA1 plays a causal role in the protection against I/R-induced renal injury and its renoprotective effect is probably mediated by inhibiting the proinflammatory cytokine TNF-α release.
Keywords: Codonopsis pilosula; Polysaccharide; Characterization; Renal ischemia/reperfusion injury; Kidney;
Molecular and rheological characterization of carrageenan solutions extracted from Kappaphycus alvarezii by Vanessa Webber; Sabrina Matos de Carvalho; Pedro Luiz Manique Barreto (1744-1749).
► Native carrageenan showed a folded structure and low molecular weights chains. ► Some rheological properties of carrageenan are similar to the commercial one. ► Atomization drying is a cheaper and faster way to obtaining raw carrageenan powder. ► Native carrageenan properties showed potential industrial application.This study evaluates and relates the molecular and rheological characteristics of native carrageenan obtained from Kappaphycus alvarezii seaweed. Native carrageenan was extracted by a differentiated methodology by atomization drying process, which reduces the time for obtaining carrageenan dry powder and minimizes costs and environmental damages. Rheological properties of native carrageenan were compared with a commercial carrageenan grade. Molecular properties were performed by SAXS and GPC analysis and the rheological properties by DMTA and stress relaxation tests. Molecular analysis proved a folded and compact molecular structure and indicated the presence of chains with different molecular weights for native carrageenan. The results obtained showed that the helix-coil transition occurs at temperature about 50 °C. The native and commercial grade carrageenan presented the characteristic of viscoelastic materials and their gel properties show a higher contribution from solid elastic component, and the initial force (F 0) was higher in commercial carrageenan than native one.
Keywords: Carrageenan; Kappaphycus alvarezii; Polysaccharide; Rheology; Molecular properties;
Biodegradable polymer based encapsulation of neem oil nanoemulsion for controlled release of Aza-A by Jayakumar Jerobin; R.S. Sureshkumar; C.H. Anjali; Amitava Mukherjee; Natarajan Chandrasekaran (1750-1756).
► Neem oil nanoemulsion was encapsulated using sodium alginate. ► Starch and PEG were used as coating agents. ► The encapsulated neem oil nanoemulsion was almost spherical in shape. ► Coated beads exhibited controlled and efficient release of Aza-A. ► Encapsulated beads can be used in various fields.Azadirachtin a biological compound found in neem have medicinal and pesticidal properties. The present work reports on the encapsulation of neem oil nanoemulsion using sodium alginate (Na-Alg) by cross linking with glutaraldehyde. Starch and polyethylene glycol (PEG) were used as coating agents for smooth surface of beads. The SEM images showed beads exhibited nearly spherical shape. Swelling of the polymeric beads reduced with coating which in turn decreased the rate of release of Aza-A. Starch coated encapsulation of neem oil nanoemulsion was found to be effective when compared to PEG coated encapsulation of neem oil nanoemulsion. The release rate of neem Aza-A from the beads into an aqueous environment was analyzed by UV–visible spectrophotometer (214 nm). The encapsulated neem oil nanoemulsion have the potential for controlled release of Aza-A. Neem oil nanoemulsion encapsulated beads coated with PEG was found to be toxic in lymphocyte cells.
Keywords: Sodium Alginate; Encapsulation; Starch; Polyethylene glycol; Glutaraldehyde;
Nanocrystalline cellulose (NCC) reinforced alginate based biodegradable nanocomposite film by Tanzina Huq; Stephane Salmieri; Avik Khan; Ruhul A. Khan; Canh Le Tien; Bernard Riedl; Carole Fraschini; Jean Bouchard; Jorge Uribe-Calderon; Musa R. Kamal; Monique Lacroix (1757-1763).
► 5 wt% NCC loading increased the tensile strength of the alginate films by 37%. ► FTIR analysis suggested hydrogen bonding between alginate and NCC. ► NCC incorporation increased the crystallinity of the alginate films. ► NCC reinforced films exhibited better thermal stability than the control.Nanocrystalline cellulose (NCC) reinforced alginate-based nanocomposite film was prepared by solution casting. The NCC content in the matrix was varied from 1 to 8% ((w/w) % dry matrix). It was found that the nanocomposite reinforced with 5 wt% NCC content exhibits the highest tensile strength which was increased by 37% compared to the control. Incorporation of NCC also significantly improved water vapor permeability (WVP) of the nanocomposite showing a 31% decrease due to 5 wt% NCC loading. Molecular interactions between alginate and NCC were supported by Fourier Transform Infrared Spectroscopy. The X-ray diffraction studies also confirmed the appearance of crystalline peaks due to the presence of NCC inside the films. Thermal stability of alginate-based nanocomposite films was improved after incorporation of NCC.
Keywords: Alginate; Nanocrystalline cellulose; Nanocomposite; Biopolymers; Morphology; Thermal properties;
Adsorption of rutin with a novel β-cyclodextrin polymer adsorbent: Thermodynamic and kinetic study by Jun Zhao; Dong-Qiang Lin; Shan-Jing Yao (1764-1770).
► Rutin adsorbed onto CroCD-TuC 3 showing the characteristic of chemical adsorption. ► Rutin/β-CD inclusion complex formation results in isosteric enthalpy increasing. ► Pore diffusion model is introduced to study the mass transfer inside the adsorbent. ► The mass transfer of rutin inside the adsorbent is the rate-restricting step.The adsorption properties toward rutin of a cyclodextrin polymer adsorbent CroCD-TuC 3 have been studied. The adsorption capacity is reduced as temperature and pH of solution rises, but increases with the increase of solvent polarity. Compared with Sephadex™ G-15 dextran gel beads, CroCD-TuC 3 shows dramatically higher isosteric enthalpy due to a significant contribution of rutin/β-cyclodextrin inclusion complex formation in CroCD-TuC 3 skeleton. A highlight in our study is that the pore diffusion model has been employed to describe the mass transfer inside the adsorbent pores. It reveals that the diffusion inside the pores is the rate-restricting step in the whole adsorption process. The effective pore diffusivity of rutin in CroCD-TuC 3 calculated is much lower than the diffusivity in diluted solution. The pore diffusion model is an available tool to investigate the profile of mass transfer inside the pores, and provides an effective method to describe adsorption kinetics.
Keywords: Cyclodextrin polymer; Adsorption isotherm; Isosteric enthalpy; Adsorption kinetics; Pore diffusion model;
Theoretical study on the mechanisms of cellulose dissolution and precipitation in the phosphoric acid–acetone process by Peng Kang; Wu Qin; Zong-Ming Zheng; Chang-Qing Dong; Yong-Ping Yang (1771-1778).
► Featuring cellulose dissolution and precipitation mechanism in H3PO4 and acetone. ► Hydrogen bond with E B of −1.61 eV favoring the dissolution of cellulose in H3PO4. ► Cellulose delocalizing in H3PO4 with E gap of 4.46 eV. ► Chemical stability of cellulose in different solvents during pretreatment.Phosphoric acid–acetone fractionation was applied to pretreat lignocellulose for production of cellulosic ethanol. Cellulose solubility properties in H2O, H3PO4 and CH3COCH3 were simulated. Atomic geometry and electronic properties were computed using density functional theory with local-density approximation. H3PO4 molecule is adsorbed between two cellulose segments, forming four hydrogen bonds with E B of −1.61 eV. Density of state for cellulose in H3PO4–cellulose system delocalizes without obvious peak. E gap of 4.46 eV is much smaller than that in other systems. Molecular dynamics simulation indicates that fragments of double glucose rings separate in the cellulose–H3PO4 interaction system. Icy CH3COCH3 addition leads to re-gathering of separated fragments. Reaction energy of cellulose in three solvents is around 3.5 eV, implying that cellulose is chemically stable. Moreover, theoretical results correspond to the experiments we have performed, showing that cellulose dissolves in H3PO4, flocculates after CH3COCH3 addition, and finally becomes more liable to be hydrolyzed into glucoses.
Keywords: Density functional theory; Dissolution; Lignocellulose; Molecular dynamic; Precipitation;
(1 → 2) and (1 → 6)-linked β-d-galactofuranan of microalga Myrmecia biatorellae, symbiotic partner of Lobaria linita by Lucimara M.C. Cordeiro; Flávio Beilke; Franciele Lima Bettim; Vanessa de Fátima Reinhardt; Yanna D. Rattmann; Marcello Iacomini (1779-1785).
► Myrmecia biatorellae produces a (1 → 2) and (1 → 6)-linked rhamnogalactofuranan. ► The structure of this rhamnogalactofuranan is new among natural polysaccharides. ► In a preliminary study, it increased the lethality of mice with sepsis induced by CLP.A structural study of the cell wall polysaccharides of Myrmecia biatorellae, the symbiotic algal partner of the lichenized fungus Lobaria linita was carried out. It produced a rhamnogalactofuranan, with a (1 → 6)-β-d-galactofuranose in the main-chain, substituted at O-2 by single units of β-d-Galf, α-l-Rhap or by side chains of 2-O-linked β-d-Galf units. The structure of the polysaccharide was established by chemical and NMR spectroscopic analysis, and is new among natural polysaccharides. Moreover, in a preliminary study, this polysaccharide increased the lethality of mice submitted to polymicrobial sepsis induced by cecal ligation and puncture, probably due to the presence of galactofuranose, which have been shown to be highy immunogenic in mammals.
Keywords: Myrmecia biatorellae; Symbiotic microalgae; Lichen; Lobaria linita; Polysaccharide; β-d-Galactofuranan;
Wound-dressing materials with antibacterial activity from electrospun polyurethane–dextran nanofiber mats containing ciprofloxacin HCl by Afeesh R. Unnithan; Nasser A.M. Barakat; P.B. Tirupathi Pichiah; Gopalsamy Gnanasekaran; R. Nirmala; Youn-Soo Cha; Che-Hun Jung; Mohamed El-Newehy; Hak Yong Kim (1786-1793).
► One step synthesis of PU–dextran–drug loaded nanofibers via e-spin. ► Good bactericidal activity against both of Gram+ve and Gram−ve bacteria. ► Applicable electrospun mat to most of the open wounds due to bactericidal activity. ► Better cell attachment and proliferation observed. ► Low cost wound dressing material.Dextran is a versatile biomacromolecule for preparing electrospun nanofibrous membranes by blending with either water-soluble bioactive agents or hydrophobic biodegradable polymers for biomedical applications. In this study, an antibacterial electrospun scaffold was prepared by electrospinning of a solution composed of dextran, polyurethane (PU) and ciprofloxacin HCl (CipHCl) drug. The obtained nanofiber mats have good morphology. The mats were characterized by various analytical techniques. The interaction parameters between fibroblasts and the PU–dextran and PU–dextran–drug scaffolds such as viability, proliferation, and attachment were investigated. The results indicated that the cells interacted favorably with the scaffolds especially the drug-containing one. Moreover, the composite mat showed good bactericidal activity against both of Gram-positive and Gram-negative bacteria. Overall, our results conclude that the introduced scaffold might be an ideal biomaterial for wound dressing applications.
Keywords: Electrospinning; Ciprofloxacin HCl; Dextran; Polyurethane; Wound dressing;
Development of low methoxy amidated pectin-based mucoadhesive patches for buccal delivery of triclosan: Effect of cyclodextrin complexation by Mario Jug; Ivan Kosalec; Francesca Maestrelli; Paola Mura (1794-1803).
► Low methoxy amidated pectin (AMP) was used as matrix to develop triclosan buccal patches. ► AMP matrix integrity was improved through addition of 20% (w/w) of Carbopol. ► TR solubility/release from patches was optimized through cyclodextrin complexation. ► β-Cyclodextrin polymer was the derivative of choice for patch formulation. ► Microbiological studies proved the good therapeutic potential of the developed formulation.A novel mucoadhesive buccal patch formulation of triclosan (TR), a broad spectrum antibacterial agent, was developed using low methoxy amidated pectin (AMP). The integrity of AMP matrix was improved by addition of 20% (w/w) Carbopol (CAR). The efficiency of β-cyclodextrin-epichlorohydrin polymer (EPIβCD) and anionic carboxymethylated β-cyclodextrin-epichlorohydrin polymer (CMEPIβCD) in optimization of TR solubility and release from such a matrix was investigated and confronted to that of parent β-cyclodextrin (βCD). Loading of TR/βCD co-ground complex into AMP/CAR matrix resulted in a biphasic release profile which was sensitive upon the hydration degree of the matrix, due to lower solubilizing efficiency of βCD, while the drug release from patches loaded with TR/EPIβCD complex was significantly faster with a constant release rate. Microbiological studies evidenced faster onset and more pronounced antibacterial action of TR/EPIβCD loaded patches, clearly demonstrating their good therapeutic potential in eradication of Streptococcus mutans, a cariogenic bacteria, from the oral cavity.
Keywords: Triclosan; β-Cyclodextrin; Water soluble polymeric β-cyclodextrin; Low methoxy amidated pectin; Carbopol; Buccal delivery;
Chemical characteristic of an anticoagulant-active sulfated polysaccharide from Enteromorpha clathrata by Xiaohui Qi; Wenjun Mao; Yan Gao; Yin Chen; Yanli Chen; Chunqi Zhao; Na Li; Chunyan Wang; Mengxia Yan; Cong Lin; Jimiao Shan (1804-1810).
► Polysaccharide FEP was isolated from Enteromorpha clathrata. ► FEP was a high arabinose-containing sulfated polysaccharide. ► The backbone of FEP was composed of specific arabinopyranose units. ► FEP possessed a good anticoagulant activity in vitro. ► FEP is a novel polysaccharide and potential source of anticoagulant.A sulfated polysaccharide FEP from marine green alga Enteromorpha clathrata was extracted with hot water and further purified by ion-exchange and size-exclusion chromatography. Results of chemical and spectroscopic analyses showed that FEP was a high arabinose-containing sulfated polysaccharide with sulfate ester of 31.0%, and its average molecular weight was about 511 kDa. The backbone of FEP was mainly composed of (1 → 4)-linked β-l-arabinopyranose residues with partially sulfate groups at the C-3 position. In vitro anticoagulant assay indicated that FEP effectively prolonged the activated partial thromboplastin time and thrombin time. The investigation demonstrated that FEP was a novel sulfated polysaccharide with different chemical characteristics from other sulfated polysaccharides from marine algae, and could be a potential source of anticoagulant.
Keywords: Enteromorpha clathrata; Sulfated polysaccharide; Chemical characteristic; Anticoagulant activity;
Conjugation of α-amylase with dextran for enhanced stability: Process details, kinetics and structural analysis by Swati B. Jadhav; Rekha S. Singhal (1811-1817).
► Effect of parameters of conjugation of α-amylase and dextran on α-amylase stability. ► Enhanced thermal and pH stability of α-amylase on conjugation with dextran. ► Conjugate showed lower inactivation rate constant with increased half life. ► Conjugation of α-amylase with dextran showed helix to turn conversion. ► Importance of covalent bonding for conjugate formation and its stability.The influence of enzyme polysaccharide interaction on enzyme stability and activity was elucidated by covalently binding dextran to a model enzyme, α-amylase. The conjugation process was optimized with respect to concentration of oxidizing agent, pH of enzyme solution, ratio of dextran to enzyme concentration, temperature and time of conjugate formation, and was found to affect the stability of α-amylase. α-Amylase conjugated under optimized conditions showed 5% loss of activity but with enhanced thermal and pH stability. Lower inactivation rate constant of conjugated α-amylase within the temperature range of 60–80 °C implied its better stability. Activation energy for denaturation of α-amylase increased by 8.81 kJ/mol on conjugation with dextran. Analysis of secondary structure of α-amylase after covalent binding with dextran showed helix to turn conversion without loss of functional properties of α-amylase. Covalent bonding was found to be mandatory for the formation of conjugate.
Keywords: Stability; Covalent binding; Conjugate; Inactivation rate constant; Activation energy; Secondary structure;
Synthesis of methylcellulose–silver nanocomposite and investigation of mechanical and antimicrobial properties by Dipanwita Maity; Md. Masud Rahaman Mollick; Dibyendu Mondal; Biplab Bhowmick; Mrinal Kanti Bain; Kalipada Bankura; Joy Sarkar; Krishnendu Acharya; Dipankar Chattopadhyay (1818-1825).
► Silver (Ag) nanoparticles were synthesized using methylcellulose (MC). ► MC–Ag nanocomposite films prepared through solution casting of mixture of MC and Ag. ► Average crystallite size of silver nanocrystal was 22.7 nm. ► The MC–Ag nanocomposite films showed enhanced mechanical properties. ► MC–Ag nanocomposites showed good antimicrobial activities.In this paper we reported preparation of methylcellulose–silver nanocomposite films by mixing of aqueous solution of methylcellulose with silver nitrate followed by casting. The silver nanoparticles were generated in methylcellulose matrix through reduction and stabilization by methylcellulose. The surface plasmon band at 412 nm indicated the formation of Ag nanoparticles. The MC–Ag nanocomposite films were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared (FTIR). The X-ray diffraction analysis of synthesized MC–Ag nanocomposite films revealed that metallic silver was present in face centered cubic crystal structure. Average crystallite size of silver nanocrystal was 22.7 nm. The FTIR peaks of as-synthesized MC–Ag nanocomposite fully designated the strong interaction between Ag nanoparticles and MC matrix. Nano-sized silver modified methylcellulose showed enhanced mechanical properties i.e. the introduction of Ag leading to both strengthening and toughening of MC matrix. The methylcellulose–silver nanocomposite films offered excellent antimicrobial activity against various microorganisms.
Keywords: Silver nanoparticles; Methylcellulose; Composite materials; Films; Mechanical property; Antimicrobial activity;
Rapid exfoliation of rectorite in quaternized carboxymethyl chitosan by Bo Liu; Xiaoying Wang; Xiaoyun Li; Xianjie Zeng; Runcang Sun; John F. Kennedy (1826-1830).
► Exfoliated quaternized carboxymethyl chitosan/rectorite nanobiocomposite was prepared. ► The exfoliation was performed in only water without any additional plasticizer. ► The silicate monolayers of rectorite were observed in the biopolymer matrix. ► Hydrogen bonds interaction existed in this nanobiocomposite. ► This nanobiocomposite had higher thermal stability than only biopolymer.Exfoliated quaternized carboxymethyl chitosan/rectorite (QCMC/REC) nanocomposite was prepared via microwave irradiation method for 70 min, which was performed in only water without any additional plasticizer. XRD, TEM, AFM, SEM and FTIR results revealed that when the mass ratio of QCMC to REC was no less than 4:1, the silicate layers of REC were completely exfoliated in QCMC matrix and were homogenous with QCMC, the surface of QCMC/REC nanobiocomposite was very smooth; two types of interactions of hydrogen bond and electrostatic attraction existed in the QCMC/REC nanobiocomposite. Thermal analysis indicated that QCMC/REC nanobiocomposite had higher thermal stability than only QCMC. Therefore, the microwave irradiation method appears to be a promising tool for preparing exfoliated biopolymer/layered silicate nanocomposites at a mild condition.
Keywords: Quaternized carboxymethyl chitosan; Rectorite; Nanocomposite; Exfoliation;
An asymmetric and slightly dimerized structure for the tetanus toxoid protein used in glycoconjugate vaccines by Ali Saber Abdelhameed; Gordon A. Morris; Gary G. Adams; Arthur J. Rowe; Olivier Laloux; Louis Cerny; Benjamin Bonnier; Pierre Duvivier; Karel Conrath; Christophe Lenfant; Stephen E. Harding (1831-1835).
► Tetanus toxoid important conjugation for carbohydrate vaccines. ► Physical nature in solution needs elucidating. ► Sedimentation velocity shows small (∼14%) dimerization. ► Dimers not in reversible equilibrium. ► Overall asymmetric conformation.Tetanus toxoid protein has been characterized with regard oligomeric state and hydrodynamic (low-resolution) shape, important parameters with regard its use in glycoconjugate vaccines. From sedimentation velocity and sedimentation equilibrium analysis in the analytical ultracentrifuge tetanus toxoid protein is shown to be mostly monomeric in solution (∼86%) with approximately 14% dimer. The relative proportions do not appear to change significantly with concentration, suggesting the two components are not in reversible equilibrium. Hydrodynamic solution conformation studies based on high precision viscometry, combined with sedimentation data show the protein to be slightly extended conformation in solution with an aspect ratio ∼3. The asymmetric structure presents a greater surface area for conjugation with polysaccharide than a more globular structure, underpinning its popular choice as a conjugation protein for glycoconjugate vaccines.
Keywords: Analytical ultracentrifugation; Hydrodynamics; Solution conformation;