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Sample records for chitosan improves maize

  1. Seed priming with chitosan improves maize germination and seedling growth in relation to physiological changes under low temperature stress

    Institute of Scientific and Technical Information of China (English)

    Ya-jing GUAN; Jin HU; Xian-ju WANG; Chen-xia SHAO

    2009-01-01

    Low temperature stress during germination and early seedling growth is an important constraint of global production of maize. The effects of seed priming with 0.25%, 0.50%, and 0.75% (w/v) chitosan solutions at 15 ℃ on the growth and physiological changes were investigated using two maize (Zea mays L.) inbred lines, HuangC (chilling-tolerant) and Mo17 (chilling-sensitive). While seed priming with chitosan had no significant effect on germination percentage under low temperature stress, it enhanced germination index, reduced the mean germination time (MGT), and increased shoot height, root length, and shoot and root dry weights in both maize lines. The decline of malondialdehyde (MDA) content and relative permeability of the plasma membrane and the increase of the concentrations of soluble sugars and proline, peroxidase (POD) activity, and catalase (CAT) activity were detected both in the chilling-sensitive and chilling-tolerant maize seedlings after priming with the three concentrations of chitosan. HuangC was less sensitive to responding to different concentrations of chitosan. Priming with 0.50% chitosan for about 60~64 h seemed to have the best effects. Thus, it suggests that seed priming with chitosan may improve the speed of germination of maize seed and benefit for seedling growth under low temperature stress.

  2. Seed priming with chitosan improves maize germination and seedling growth in relation to physiological changes under low temperature stress*

    OpenAIRE

    Guan, Ya-jing; Hu, Jin; Wang, Xian-Ju; Shao, Chen-xia

    2009-01-01

    Low temperature stress during germination and early seedling growth is an important constraint of global production of maize. The effects of seed priming with 0.25%, 0.50%, and 0.75% (w/v) chitosan solutions at 15 °C on the growth and physiological changes were investigated using two maize (Zea mays L.) inbred lines, HuangC (chilling-tolerant) and Mo17 (chilling-sensitive). While seed priming with chitosan had no significant effect on germination percentage under low temperature stress, it en...

  3. Synergistic Effects of Plant Growth Promoting Rhizobacteria and Chitosan on In Vitro Seeds Germination, Greenhouse Growth, and Nutrient Uptake of Maize (Zea mays L.).

    Science.gov (United States)

    Agbodjato, Nadège A; Noumavo, Pacôme A; Adjanohoun, Adolphe; Agbessi, Léonce; Baba-Moussa, Lamine

    2016-01-01

    This study aimed to assess the effects of three plant growth promoting rhizobacteria (PGPR) and chitosan either singly or in combination on maize seeds germination and growth and nutrient uptake. Maize seeds were treated with chitosan and bacterial solution. The germination and growth tests were carried out in square Petri dishes and plastic pots. The combination chitosan-A. lipoferum-P. fluorescens has increased the seeds vigor index up to 36.44% compared to the control. In comparison to the control, P. putida has significantly improved root weight (44.84%) and germinated seed weight (31.39%) whereas chitosan-P. putida has increased the shoot weight (65.67%). For the growth test, the maximal heights (17.66%) were obtained by plants treated with the combination A. lipoferum-P. fluorescens-P. putida. Chitosan-P. fluorescens induced the highest increases of leaves per plant (50.09%), aerial (84.66%), and underground biomass (108.77%) production. The plants inoculated with A. lipoferum had the large leaf areas with an increase of 54.08%, while combinations P. fluorescens-P. putida and chitosan-A. lipoferum improved the aerial and underground dry matter of plants to 26.35% and 18.18%. The nitrogen content of the plants was increased by chitosan-A. lipoferum-P. fluorescens-P. putida with an increasing of 41.61%. The combination of chitosan and PGPR can be used as biological fertilizers to increase maize production. PMID:26904295

  4. Synergistic Effects of Plant Growth Promoting Rhizobacteria and Chitosan on In Vitro Seeds Germination, Greenhouse Growth, and Nutrient Uptake of Maize (Zea mays L.

    Directory of Open Access Journals (Sweden)

    Nadège A. Agbodjato

    2016-01-01

    Full Text Available This study aimed to assess the effects of three plant growth promoting rhizobacteria (PGPR and chitosan either singly or in combination on maize seeds germination and growth and nutrient uptake. Maize seeds were treated with chitosan and bacterial solution. The germination and growth tests were carried out in square Petri dishes and plastic pots. The combination chitosan-A. lipoferum-P. fluorescens has increased the seeds vigor index up to 36.44% compared to the control. In comparison to the control, P. putida has significantly improved root weight (44.84% and germinated seed weight (31.39% whereas chitosan-P. putida has increased the shoot weight (65.67%. For the growth test, the maximal heights (17.66% were obtained by plants treated with the combination A. lipoferum-P. fluorescens-P. putida. Chitosan-P. fluorescens induced the highest increases of leaves per plant (50.09%, aerial (84.66%, and underground biomass (108.77% production. The plants inoculated with A. lipoferum had the large leaf areas with an increase of 54.08%, while combinations P. fluorescens-P. putida and chitosan-A. lipoferum improved the aerial and underground dry matter of plants to 26.35% and 18.18%. The nitrogen content of the plants was increased by chitosan-A. lipoferum-P. fluorescens-P. putida with an increasing of 41.61%. The combination of chitosan and PGPR can be used as biological fertilizers to increase maize production.

  5. ADVANCES IN TRANSGENIC MAIZE FOR QUALITY IMPROVEMENT

    Directory of Open Access Journals (Sweden)

    M.Rajendar Reddy

    2015-12-01

    Full Text Available Maize (Zea mays is a major food and animal feed worldwide and occupies a relevant place in the world economy and trade as an industrial grain crop. Currently more than 70% of maize production is used for food and feed; therefore, knowledge of genes involved in grain structure and chemical is important for improving the nutritional and food-making properties of maize. It is a good source of carbohydrates, fats, proteins, vitamins and minerals but deficient in two essential amino acids, Viz., lysine and tryptophan. To overcome this problem and to improve the above quality characters the maize breeders have followed different strategies like opaque 2, QPM and development of transgenic maize with improved quality characters. Finally we can conclude that the conventional breeding techniques and now plant biotechnology are helping meet the growing demand for food production, nutrition security while preserving our environment for future generations

  6. Synergistic Effects of Plant Growth Promoting Rhizobacteria and Chitosan on In Vitro Seeds Germination, Greenhouse Growth, and Nutrient Uptake of Maize (Zea mays L.)

    OpenAIRE

    Agbodjato, Nadège A.; Pacôme A. Noumavo; Adolphe Adjanohoun; Léonce Agbessi; Lamine Baba-Moussa

    2016-01-01

    This study aimed to assess the effects of three plant growth promoting rhizobacteria (PGPR) and chitosan either singly or in combination on maize seeds germination and growth and nutrient uptake. Maize seeds were treated with chitosan and bacterial solution. The germination and growth tests were carried out in square Petri dishes and plastic pots. The combination chitosan-A. lipoferum-P. fluorescens has increased the seeds vigor index up to 36.44% compared to the control. In comparison to the...

  7. Cu-Chitosan Nanoparticle Mediated Sustainable Approach To Enhance Seedling Growth in Maize by Mobilizing Reserved Food.

    Science.gov (United States)

    Saharan, Vinod; Kumaraswamy, R V; Choudhary, Ram Chandra; Kumari, Sarita; Pal, Ajay; Raliya, Ramesh; Biswas, Pratim

    2016-08-10

    Food crop seedlings often have susceptibility to various abiotic and biotic stresses. Therefore, in the present study, we investigated the impact of Cu-chitosan nanoparticles (NPs) on physiological and biochemical changes during maize seedling growth. Higher values of percent germination, shoot and root length, root number, seedling length, fresh and dry weight, and seed vigor index were obtained at 0.04-0.12% concentrations of Cu-chitosan NPs as compared to water, CuSO4, and bulk chitosan treatments. Cu-chitosan NPs at the same concentrations induced the activities of α-amylase and protease enzymes and also increased the total protein content in germinating seeds. The increased activities of α-amylase and protease enzymes corroborated with decreased content of starch and protein, respectively, in the germinating seeds. Cu-chitosan NPs at 0.16% and CuSO4 at 0.01% concentrations showed inhibitory effect on seedling growth. The observed results on seedling growth could be explained by the toxicity of excess Cu and growth promotory effect of Cu-chitosan NPs. Physiological and biochemical studies suggest that Cu-chitosan NPs enhance the seedling growth of maize by mobilizing the reserved food, primarily starch, through the higher activity of α-amylase. PMID:27460439

  8. Maize seed coatings and seedling sprayings with chitosan and hydrogen peroxide: their influence on some phenological and biochemical behaviors

    OpenAIRE

    Lizárraga-Paulín, Eva-Guadalupe; Miranda-Castro, Susana-Patricia; Moreno-Martínez, Ernesto; Lara-Sagahón, Alma-Virginia; Torres-Pacheco, Irineo

    2013-01-01

    Objective: To evaluate the effect of chitosan (CH) and hydrogen peroxide (H2O2) seed coatings and seedling sprinklings on two different maize varieties by measuring their phenology, the H2O2 presence, the catalase (CAT) activity, and the protein quantity. Methods: Seven groups of ten seeds for each maize variety were treated with CH (2% (20 g/L) and 0.2% (2 g/L)) or H2O2 (8 mmol/L) by coating, sprinkling, or both. Germination and seedling growth were measured. One month after germination, the...

  9. Adoption of Improved Maize Seed Varieties in Southern Zambia

    OpenAIRE

    Thomson Kalinda; Gelson Tembo; Elias Kuntashula

    2014-01-01

    Maize is the principal agricultural crop produced by Zambian smallholder farmers for household consumption and sale. Their production strategy is therefore important in meeting food security and income needs. This study uses data collected from a survey of a random sample of farm households in southern Zambia to develop a Tobit regression model. The model identifies farm and farmer characteristics important for adoption of improved maize seed varieties as well as to determine the role of farm...

  10. Maize seed coatings and seedling sprayings with chitosan and hydrogen peroxide:their influence on some phenological and biochemical behaviors

    Institute of Scientific and Technical Information of China (English)

    Eva-Guadalupe LIZ(A)RRAGA-PAUL(I)N; Susana-Patricia MIRANDA-CASTRO; Ernesto MORENO-MART(I)NEZ; Alma-Virginia LARA-SAGAH(O)N; Irineo TORRES-PACHECO

    2013-01-01

    Objective:To evaluate the effect of chitosan(CH)and hydrogen peroxide(H2O2)seed coatings and seedling sprinklings on two different maize varieties by measuring their phenology,the H2O2 presence,the catalase (CAT)activity,and the protein quantity.Methods:Seven groups of ten seeds for each maize variety were treated with CH(2%(20 g/L)and 0.2%(2 g/L))or H2O2(8 mmol/L)by coating,sprinkling,or both.Germination and seedling growth were measured.One month after germination,the presence of H2O2 in seedlings in the coated seed treatments was evaluated.Protein content and CAT activity were determined under all treatments.Results:H2O2 seed coating enhanced the germination rate and increased seedling and stem length in the quality protein maize(QPM)variety.Seedlings had a higher emergence velocity under this treatment in both varieties.CH and H2O2 sprinklings did not have an effect on seedling phenology.Exogenous application of H2O2 promoted an increase of endogenous H2O2.CH and H2O2 seedling sprinkling increased the protein content in both maize varieties,while there was no significant effect on the CAT activity of treated seeds and seedlings.Conclusions:CH and H2O2 enhance some phenological and biochemical features of maize depending on their method of application.

  11. Studies for improving and formulating of chitosan-based coatings by radiation treatment for fruit preservation

    International Nuclear Information System (INIS)

    Presented are the investigations: effect of chitosan on fruit - spoiling microorganism and enhancement of antifungal activity by radiation treatment; improvement of antimicrobial activity of chitosan by its derivatives synthesis in combination with radiation treatment; dependence of chitosan antimicrobial activity on molecular weight and distribution of molecular weight; comparative study on the antifungal activity of chitosan of various origins tested in different conditions of radiation treatment and culture mediums; formulation of chitosan membranes and for their properties in mango coating; effectiveness of chitosan-based coatings on fresh fruit appearance and quality during storage; influence of irradiated chitosan on rice plant growing in media contaminated with salt and heavy metals; effect of chitosan solution varied in concentration and molecular weight on seed germination and seedling growth of groundnut, soybean and cabbage. (NHA)

  12. Combined effect of chitosan and water activity on growth and fumonisin production by Fusarium verticillioides and Fusarium proliferatum on maize-based media.

    Science.gov (United States)

    Ferrochio, Laura V; Cendoya, Eugenia; Zachetti, Vanessa G L; Farnochi, Maria C; Massad, Walter; Ramirez, Maria L

    2014-08-18

    The objectives of the present study were to determine the in vitro efficacy of chitosan (0.5, 1.0, 2.0 and 3.0mg/mL) under different water availabilities (0.995, 0.99, 0.98, 0.96 and 0.93) at 25°C on lag phase, growth rate and fumonisin production by isolates of Fusarium verticillioides and Fusarium proliferatum. The presence of chitosan affected growth and fumonisin production, and this effect was dependent on the dose and aW treatment used. The presence of chitosan increased the lag phase, and reduced the growth rate of both Fusarium species significantly at all concentrations used, especially at 0.93 aW. Also, significant reduction of fumonisin production was observed in both Fusarium species at all conditions assayed. The present study has shown the combined effects of chitosan and aW on growth and fumonisin production by the two most important Fusarium species present on maize. Low molecular weight (Mw) chitosan with more than 70% of degree of deacetylation (DD) at 0.5mg/mL was able to significantly reduce growth rate and fumonisin production on maize-based media, with maximum levels of reduction in both parameters obtained at the highest doses used. As fumonisins are unavoidable contaminants in food and feed chains, their presence needs to be reduced to minimize their effects on human and animal health and to diminish the annual market loss through rejected maize. In this scenario post-harvest use of chitosan could be an important alternative treatment. PMID:24929683

  13. Nanoparticle-mediated interplay of chitosan and melatonin for improved wound epithelialisation.

    Science.gov (United States)

    Blažević, Filip; Milekić, Tamara; Romić, Marieta Duvnjak; Juretić, Marina; Pepić, Ivan; Filipović-Grčić, Jelena; Lovrić, Jasmina; Hafner, Anita

    2016-08-01

    Herein, we propose an innovative approach to improving wound healing. Our strategy is to deliver melatonin locally at the wound site by means of lecithin/chitosan nanoparticles. We used four types of chitosan that differed in terms of molecular weight and/or deacetylation degree. Melatonin encapsulation efficiency, nanoparticle size, zeta potential, biocompatibility and in vitro drug release were studied as a function of the type of chitosan used in preparation. The nanoparticles were evaluated in terms of their potential to promote wound epithelialisation via an in vitro scratch assay using a human keratinocyte (HaCaT) monolayer. The model wounds were treated with nanoparticle suspensions at a chitosan concentration of 5μgml(-1), which was based on preceding cell biocompatibility studies. Nanoparticles prepared with different types of chitosan showed similar effect on the keratinocyte proliferation/migration. Nanoparticle-mediated interplay of chitosan and melatonin was shown to be crucial for improved wound epithelialisation. PMID:27112895

  14. Adoption of Improved Maize Seed Varieties in Southern Zambia

    Directory of Open Access Journals (Sweden)

    Thomson Kalinda

    2014-01-01

    Full Text Available Maize is the principal agricultural crop produced by Zambian smallholder farmers for household consumption and sale. Their production strategy is therefore important in meeting food security and income needs. This study uses data collected from a survey of a random sample of farm households in southern Zambia to develop a Tobit regression model. The model identifies farm and farmer characteristics important for adoption of improved maize seed varieties as well as to determine the role of farmer perceptions of technology attributes in maize varietal adoption. The results indicate that expectations about output price and yield are important determinants of adoption. Other factors directly correlated with the probability of adoption include the status of being male-headed, farm size and membership to farmer organizations. Households with more wealth and educated heads were also significantly more likely to adopt improved varieties. Some of the policy implications of these findings are that intervention strategies should be designed and implemented to encourage poor households and those with low levels of formal education to participate in local farmer organizations. The positive interaction between membership to organizations and the adoption of technologies also suggests that group based extension approaches should be encouraged not only for their role in collective action but also for their positive impact on information diffusion and technology adoption.

  15. Cross-linked chitosan improves the mechanical properties of calcium phosphate-chitosan cement.

    Science.gov (United States)

    Aryaei, Ashkan; Liu, Jason; Jayatissa, Ahalapitiya H; Champa Jayasuriya, A

    2015-09-01

    Calcium phosphate (CaP) cements are highly applicable and valuable materials for filling bone defects by minimally invasive procedures. The chitosan (CS) biopolymer is also considered as one of the promising biomaterial candidates in bone tissue engineering. In the present study, some key features of CaP-CS were significantly improved by developing a novel CaP-CS composite. For this purpose, CS was the first cross-linked with tripolyphosphate (TPP) and then mixed with CaP matrix. A group of CaP-CS samples without cross-linking was also prepared. Samples were fabricated and tested based on the known standards. Additionally, the effect of different powder (P) to liquid (L) ratios was also investigated. Both cross-linked and uncross-linked CaP-CS samples showed excellent washout resistance. The most significant effects were observed on Young's modulus and compressive strength in wet condition as well as surface hardness. In dry conditions, the Young's modulus of cross-linked samples was slightly improved. Based on the presented results, cross-linking does not have a significant effect on porosity. As expected, by increasing the P/L ratio of a sample, ductility and injectability were decreased. However, in the most cases, mechanical properties were enhanced. The results have shown that cross-linking can improve the mechanical properties of CaP-CS and hence it can be used for bone tissue engineering applications. PMID:26046262

  16. Hydrophobic surface modification of chitosan gels by stearyl for improving the activity of immobilized lipase

    Institute of Scientific and Technical Information of China (English)

    Hong Tao Deng; Juan Juan Wang; Miao Ma; Zhong Yang Liu; Fei Zheng

    2009-01-01

    The hydrophobic surface modification of chitosan gels was carded out using the amidating reaction of amido groups on a gel surface with steafic acid activated by 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC) and N-hydroxy-succinimide (NHS). Lipases from Candida rugosa were adsorbed on the nascent chitosan gels (CS) and stearyl-modified gels (SCS) with different degrees of amidation. The increased surface hydrophobicity of chitosan gels improved the adsorption capacity and activity of the immobilized lipase. SCS with 31.46% amidation showed the maximum activity retention (83.43%). The experimental results suggest that the moderate surface hydrophilicity/hydropbobicity of chitosan gels is necessary for the improvement of the activity of immobilized lipase.

  17. Silica Modified Chitosan/Polyethylenimine Nanogel for Improved Stability and Gene Carrier Ability.

    Science.gov (United States)

    Tian, Rui; Xian, Lei; Li, Yuan; Zheng, Xingwang

    2016-05-01

    Although chitosan-based hydrogel has been widely used as a gene carrier material, further improvement in this aspect is still needed. Herein a new method was proposed for preparing the effective chitosan-based gene carrier nanogel. The new method based on the fact that supra-molecular interactions between silica, polyethylenimine (PEI) and chitosan could be used to self-assemble them together to form a rigid and stable gene carrier material in the reverse microemulsion system. When compared with chemical cross-linking route, the proposed method is simple and easy to adjust components of the resulting nanogel and, therefore, can improve its gene carrying ability. Our results showed that, doping of the PEI and silica into the chitosan hydrogel obviously increased its strength, stability and gene carrying ability. PMID:27483943

  18. Comparative analysis of maize (Zea mays) crop performance: natural variation, incremental improvements and economic impacts.

    Science.gov (United States)

    Leibman, Mark; Shryock, Jereme J; Clements, Michael J; Hall, Michael A; Loida, Paul J; McClerren, Amanda L; McKiness, Zoe P; Phillips, Jonathan R; Rice, Elena A; Stark, Steven B

    2014-09-01

    Grain yield from maize hybrids continues to improve through advances in breeding and biotechnology. Despite genetic improvements to hybrid maize, grain yield from distinct maize hybrids is expected to vary across growing locations due to numerous environmental factors. In this study, we examine across-location variation in grain yield among maize hybrids in three case studies. The three case studies examine hybrid improvement through breeding, introduction of an insect protection trait or introduction of a transcription factor trait associated with increased yield. In all cases, grain yield from each hybrid population had a Gaussian distribution. Across-location distributions of grain yield from each hybrid partially overlapped. The hybrid with a higher mean grain yield typically outperformed its comparator at most, but not all, of the growing locations (a 'win rate'). These results suggest that a broad set of environmental factors similarly impacts grain yields from both conventional- and biotechnology-derived maize hybrids and that grain yields among two or more hybrids should be compared with consideration given to both mean yield performance and the frequency of locations at which each hybrid 'wins' against its comparators. From an economic standpoint, growers recognize the value of genetically improved maize hybrids that outperform comparators in the majority of locations. Grower adoption of improved maize hybrids drives increases in average U.S. maize grain yields and contributes significant value to the economy. PMID:24851925

  19. Injectable porous nano-hydroxyapatite/chitosan/tripolyphosphate scaffolds with improved compressive strength for bone regeneration.

    Science.gov (United States)

    Uswatta, Suren P; Okeke, Israel U; Jayasuriya, Ambalangodage C

    2016-12-01

    In this study we have fabricated porous injectable spherical scaffolds using chitosan biopolymer, sodium tripolyphosphate (TPP) and nano-hydroxyapatite (nHA). TPP was primarily used as an ionic crosslinker to crosslink nHA/chitosan droplets. We hypothesized that incorporating nHA into chitosan could support osteoconduction by emulating the mineralized cortical bone structure, and improve the Ultimate Compressive Strength (UCS) of the scaffolds. We prepared chitosan solutions with 0.5%, 1% and 2% (w/v) nHA concentration and used simple coacervation and lyophilization techniques to obtain spherical scaffolds. Lyophilized spherical scaffolds had a mean diameter of 1.33mm (n=25). Further, portion from each group lyophilized scaffolds were soaked and dried to obtain Lyophilized Soaked and Dried (LSD) scaffolds. LSD scaffolds had a mean diameter of 0.93mm (n=25) which is promising property for the injectability. Scanning Electron Microscopy images showed porous surface morphology and interconnected pore structures inside the scaffolds. Lyophilized and LSD scaffolds had surface pores lyophilized scaffolds at 3.93MPa. Standardize UCS values were 79.98MPa and 357MPa for 2% nHA/chitosan lyophilized and LSD particles respectively. One-way ANOVA results showed a significant increase (plyophilized scaffolds compared to 0% and 0.5% nHA/chitosan lyophilized scaffolds. Moreover, 2% nHA LSD scaffolds had significantly increased (plyophilized scaffolds. In a drawback, all scaffolds have lost their mechanical properties by 95% on the 2nd day when fully immersed in phosphate buffered saline. Additionally live and dead cell assay showed no cytotoxicity and excellent osteoblast attachment to both lyophilized and LSD scaffolds at the end of 14th day of in vitro studies. 2% nHA/chitosan scaffolds showed higher osteoblast attachment than 0% nHA/chitosan scaffolds. PMID:27612741

  20. Comparative population genomics of maize domestication and improvement

    Science.gov (United States)

    Domestication and modern breeding represent exemplary case studies of evolution in action. Maize is an outcrossing species with a complex genome, and an understanding of maize evolution is thus relevant for both plant and animal systems. This study is the largest plant resequencing effort to date, ...

  1. Improving yield and nitrogen nutrition of maize (zea mays, L) through azotobacterization and sulphur fertilization

    International Nuclear Information System (INIS)

    The experiment was conducted in plastic pots each, containing 20 kg soil to study the effect of sulphur (20, 40, 60 kg S/ha) and azotobacter inoculation alone and in combination on the yield and nutrition of maize (cv. Azam). A basal dose of nitrogen (N), phosphorus (P/sub 2/O/sub 3/) and potash (K/sub 2/O) at 40, 80, 40 kg/ha was applied to each pot. The results revealed that increasing rates of sulphur application significantly improved the total biomass yield by 31.4 to 34.0 percent and total biomass N yield of maize by 61.0 to 65.0 percent as compared to control receiving no sulphur or azotobacter. The effect of sulphur application in improving the total biomass and biomass N yield of maize was statistically at par with that of azotobacter inoculation alone. Application to sulphur at all the applied levels along with azotobacter inoculation further improved significantly the total biomass yield by 66.0 to 70.0 percent and total biomass N yield by 99.0 to 104.0 percent as compared to control receiving no sulphur or azotobacter. Azotobacterization of maize in the presence of sulphur fertilization further improved significantly the total biomass yield by 24.1 to 29.0 percent and total biomass N yield of maize by 13.0 to 17.0 percent as compared to control receiving azotobacter alone. Inoculation of maize with azotobacter alone or in combination with sulphur markedly stimulated the azotobacter population in the root rhizospheric soil as compared to non-rhizospheric (free) soil sulphur alone had no effect in stimulating the azotobacter population in the rhizospheric soil as compared to non-rhizospheric (free) soil of maize plant. Azotobacterization of maize alone or in the presence of sulphur fertilization significantly improved the maize height. (author)

  2. Input subsidies to improve smallholder maize productivity in Malawi: toward an african green revolution.

    OpenAIRE

    Glenn Denning; Patrick Kabambe; Pedro Sanchez; Alia Malik; Rafael Flor; Rebbie Harawa; Phelire Nkhoma; Colleen Zamba; Clement Banda; Chrispin Magombo; Michael Keating; Justine Wangila; Jeffrey Sachs

    2009-01-01

    Recent hikes in food prices have created economic and social turmoil in many African countries. But in Malawi, fertilizer and seed subsidies have enabled small-scale farmers to improve maize productivity and achieve food security.

  3. Development, applications and distribution of DNA markers for genetic information for sorghum and maize improvement

    International Nuclear Information System (INIS)

    This final report summarizes the progress made towards the enhancement and distribution of genetic resources (e.g. genetic stocks, seed and DNA clones) used for basic and applied aspects of the genetic improvement of maize and sorghum. The genetic maps of maize and sorghum were improved through comparative mapping of RFLP loci detected by 124 maize cDNA clones and through the development of a new mapping population of maize. Comparative mapping between maize and sorghum and maize and rice, using the set of 124 maize cDNA clones (and other clones) in each study, substantiated previous observations of extensive conservation of locus order but it also provided strong evidence of numerous large-scale chromosomal rearrangements. The new mapping population for maize (intermated B73xMo17, 'IBM') was created by random intermating during the first segregating generation. Intermating for four generations prior to the derivation of recombinant inbred lines (RILs) increased the frequency of recombinants at many regions of the maize genome and provided better genetic resolution of locus order. Expansion of the maize genetic map was not uniform along the length of a linkage group and was less than the theoretical expectation. The 350 IBM RILs were genotyped at 512 loci detected by DNA clones, including 76 of the 124 supported by this contract. The production of the sorghum mapping population of RILs from the cross CK60xPI229828 has been delayed by weather conditions that were not conducive to plant growth and seed development. Seed of the IBM RILs have been distributed (approximately 5000 RILs in total) to 16 research organizations in the public and private sector. The DNA clones have been distributed (1,206 in total) to nine research labs. Further distribution of the seed and clones will be managed by curators at stock centers in the public domain. (author)

  4. Chitosan-based leather functional coatings with improved antimicrobial properties

    OpenAIRE

    Amaral, J.S.; Fernandes, I.P.; De Pinto, V; Ferreira, M. J.; Barreiro, M.F.

    2012-01-01

    Among the interesting biological activities that have been ascribed to chitosan, the antimicrobial activity is probably the one that generates the higher number of applications. Developing antimicrobial coatings for footwear components to be used in direct contact with the feet is of great interest; both at industrial level (reducing the possibility of material deterioration and quality loss) and from the consumer’s point of view (decreasing skin infections and minimizing...

  5. Chitosan Improves Anti-Biofilm Efficacy of Gentamicin through Facilitating Antibiotic Penetration

    Directory of Open Access Journals (Sweden)

    Haibo Mu

    2014-12-01

    Full Text Available Antibiotic overuse is one of the major drivers in the generation of antibiotic resistant “super bugs” that can potentially cause serious effects on health. In this study, we reported that the polycationic polysaccharide, chitosan could improve the efficacy of a given antibiotic (gentamicin to combat bacterial biofilms, the universal lifestyle of microbes in the world. Short- or long-term treatment with the mixture of chitosan and gentamicin resulted in the dispersal of Listeria monocytogenes (L. monocytogenes biofilms. In this combination, chitosan with a moderate molecular mass (~13 kDa and high N-deacetylation degree (~88% DD elicited an optimal anti-biofilm and bactericidal activity. Mechanistic insights indicated that chitosan facilitated the entry of gentamicin into the architecture of L. monocytogenes biofilms. Finally, we showed that this combination was also effective in the eradication of biofilms built by two other Listeria species, Listeria welshimeri and Listeria innocua. Thus, our findings pointed out that chitosan supplementation might overcome the resistance of Listeria biofilms to gentamicin, which might be helpful in prevention of gentamicin overuse in case of combating Listeria biofilms when this specific antibiotic was recommended.

  6. Chitosan scaffold modified with D-(+) raffinose and enriched with thiol-modified gelatin for improved osteoblast adhesion.

    Science.gov (United States)

    Galli, C; Parisi, L; Elviri, L; Bianchera, A; Smerieri, A; Lagonegro, P; Lumetti, S; Manfredi, E; Bettini, R; Macaluso, G M

    2016-02-01

    The aim of the present study was to investigate whether chitosan-based scaffolds modified with D-(+) raffinose and enriched with thiol-modified gelatin could selectively improve osteoblast adhesion and proliferation. 2, 3 and 4.5% chitosan films were prepared. Chitosan suitability for tissue engineering was confirmed by protein adsorption assay. Scaffolds were incubated with a 2.5 mg ml(-1) BSA solution and the decrease of protein content in the supernatants was measured by spectrophotometry. Chitosan films were then enriched with thiol-modified gelatin and their ability to bind BSA was also measured. Then, 2% chitosan discs with or without thiol-modified gelatin were used as culture substrates for MC3T3-E1 cells. After 72 h cells were stained with trypan blue or with calcein AM and propidium iodide for morphology, viability and proliferation assays. Moreover, cell viability was measured at 48, 72, 96 and 168 h to obtain a growth curve. Chitosan films efficiently bound and retained BSA proportionally to the concentration of chitosan discs. The amount of protein retained was higher on chitosan enriched with thiol-modified gelatin. Moreover, chitosan discs allowed the adhesion and the viability of cells, but inhibited their proliferation. The functionalization of chitosan with thiol-modified gelatin enhanced cell spreading and proliferation. Our data confirm that chitosan is a suitable material for tissue engineering. Moreover, our data show that the enrichment of chitosan with thiol-modified gelatin enhances its biological properties. PMID:26836318

  7. Label-free immunosensor based on one-step electrodeposition of chitosan-gold nanoparticles biocompatible film on Au microelectrode for determination of aflatoxin B1 in maize.

    Science.gov (United States)

    Ma, Haihua; Sun, Jizhou; Zhang, Yuan; Bian, Chao; Xia, Shanhong; Zhen, Tong

    2016-06-15

    Gold nanoparticles (AuNPs) embedded in chitosan (CHI) film, well-dispersed and smaller in size (about 10 nm), were fabricated by one-step electrodeposion on Au microelectrode in solution containing chitosan and chloride trihydrate. The nano-structure CHI-AuNPs composite film offers abundant amine groups, good conductivity, excellent biocompatibility and stability for antibody immobilization. The combination of aflatoxin B1 (AFB1) with immobilized antibody introduces a barrier to electron transfer, resulting in current decreasement. The morphologies and characterizations of modified microelectrodes were investigated by scanning electron microscope (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and Fourier transform infrared spectroscopy (FT-IR). The proposed non-enzyme and label-free immunosensor exhibited high sensitive amperometric response to AFB1 concentration in two linear ranges of 0.1 to 1 ng mL(-1) and 1 to 30 ng mL(-1), with the detection limit of 0.06 ng mL(-1) (S/N=3). The immunoassay was also applied for analysis of maize samples spiked with AFB1. Considering the sample extraction procedure, the linear range and limit of detection were assessed to be 1.6-16 ng mL(-1) and 0.19 ng mL(-1) respectively. The simple method showed good fabrication controllability and reproducibility for immunosensor design. PMID:26851579

  8. Collagen tissue treated with chitosan solutions in carbonic acid for improved biological prosthetic heart valves.

    Science.gov (United States)

    Gallyamov, Marat O; Chaschin, Ivan S; Khokhlova, Marina A; Grigorev, Timofey E; Bakuleva, Natalia P; Lyutova, Irina G; Kondratenko, Janna E; Badun, Gennadii A; Chernysheva, Maria G; Khokhlov, Alexei R

    2014-04-01

    Calcification of bovine pericardium dramatically shortens typical lifetimes of biological prosthetic heart valves and thus precludes their choice for younger patients. The aim of the present work is to demonstrate that the calcification is to be mitigated by means of treatment of bovine pericardium in solutions of chitosan in carbonic acid, i.e. water saturated with carbon dioxide at high pressure. This acidic aqueous fluid unusually combines antimicrobial properties with absolute biocompatibility as far as at normal pressure it decomposes spontaneously and completely into H2O and CO2. Yet, at high pressures it can protonate and dissolve chitosan materials with different degrees of acetylation (in the range of 16-33%, at least) without any further pretreatment. Even exposure of the bovine pericardium in pure carbonic acid solution without chitosan already favours certain reduction in calcification, somewhat improved mechanical properties, complete biocompatibility and evident antimicrobial activity of the treated collagen tissue. The reason may be due to high extraction ability of this peculiar compressed fluidic mixture. Moreover, exposure of the bovine pericardium in solutions of chitosan in carbonic acid introduces even better mechanical properties and highly pronounced antimicrobial activity of the modified collagen tissue against adherence and biofilm formation of relevant Gram-positive and Gram-negative strains. Yet, the most important achievement is the detected dramatic reduction in calcification for such modified collagen tissues in spite of the fact that the amount of the thus introduced chitosan is rather small (typically ca. 1wt.%), which has been reliably detected using original tritium labelling method. We believe that these improved properties are achieved due to particularly deep and uniform impregnation of the collagen matrix with chitosan from its pressurised solutions in carbonic acid. PMID:24582232

  9. Collagen tissue treated with chitosan solutions in carbonic acid for improved biological prosthetic heart valves

    Energy Technology Data Exchange (ETDEWEB)

    Gallyamov, Marat O., E-mail: glm@spm.phys.msu.ru [Faculty of Physics, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation); Chaschin, Ivan S. [Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation); Khokhlova, Marina A. [Faculty of Physics, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Grigorev, Timofey E. [Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation); Bakuleva, Natalia P.; Lyutova, Irina G.; Kondratenko, Janna E. [Bakulev Scientific Center for Cardiovascular Surgery of the Russian Academy of Medical Sciences, Roublyevskoe Sh. 135, Moscow 121552 (Russian Federation); Badun, Gennadii A.; Chernysheva, Maria G. [Radiochemistry Division, Faculty of Chemistry, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Khokhlov, Alexei R. [Faculty of Physics, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation)

    2014-04-01

    Calcification of bovine pericardium dramatically shortens typical lifetimes of biological prosthetic heart valves and thus precludes their choice for younger patients. The aim of the present work is to demonstrate that the calcification is to be mitigated by means of treatment of bovine pericardium in solutions of chitosan in carbonic acid, i.e. water saturated with carbon dioxide at high pressure. This acidic aqueous fluid unusually combines antimicrobial properties with absolute biocompatibility as far as at normal pressure it decomposes spontaneously and completely into H{sub 2}O and CO{sub 2}. Yet, at high pressures it can protonate and dissolve chitosan materials with different degrees of acetylation (in the range of 16–33%, at least) without any further pretreatment. Even exposure of the bovine pericardium in pure carbonic acid solution without chitosan already favours certain reduction in calcification, somewhat improved mechanical properties, complete biocompatibility and evident antimicrobial activity of the treated collagen tissue. The reason may be due to high extraction ability of this peculiar compressed fluidic mixture. Moreover, exposure of the bovine pericardium in solutions of chitosan in carbonic acid introduces even better mechanical properties and highly pronounced antimicrobial activity of the modified collagen tissue against adherence and biofilm formation of relevant Gram-positive and Gram-negative strains. Yet, the most important achievement is the detected dramatic reduction in calcification for such modified collagen tissues in spite of the fact that the amount of the thus introduced chitosan is rather small (typically ca. 1 wt.%), which has been reliably detected using original tritium labelling method. We believe that these improved properties are achieved due to particularly deep and uniform impregnation of the collagen matrix with chitosan from its pressurised solutions in carbonic acid. - Highlights: • Treatment of GA

  10. Improved mucoadhesion and cell uptake of chitosan and chitosan oligosaccharide surface-modified polymer nanoparticles for mucosal delivery of proteins.

    Science.gov (United States)

    Dyawanapelly, Sathish; Koli, Uday; Dharamdasani, Vimisha; Jain, Ratnesh; Dandekar, Prajakta

    2016-08-01

    The main aim of the present study was to compare mucoadhesion and cellular uptake efficiency of chitosan (CS) and chitosan oligosaccharide (COS) surface-modified polymer nanoparticles (NPs) for mucosal delivery of proteins. We have developed poly (D, L-lactide-co-glycolide) (PLGA) NPs, surface-modified COS-PLGA NPs and CS-PLGA NPs, by using double emulsion solvent evaporation method, for encapsulating bovine serum albumin (BSA) as a model protein. Surface modification of NPs was confirmed using physicochemical characterization methods such as particle size and zeta potential, SEM, TEM and FTIR analysis. Both surface-modified PLGA NPs displayed a slow release of protein compared to PLGA NPs. Furthermore, we have explored the mucoadhesive property of COS as a material for modifying the surface of polymeric NPs. During in vitro mucoadhesion test, positively charged COS-PLGA NPs and CS-PLGA NPs exhibited enhanced mucoadhesion, compared to negatively charged PLGA NPs. This interaction was anticipated to improve the cell interaction and uptake of NPs, which is an important requirement for mucosal delivery of proteins. All nanoformulations were found to be safe for cellular delivery when evaluated in A549 cells. Moreover, intracellular uptake behaviour of FITC-BSA loaded NPs was extensively investigated by confocal laser scanning microscopy and flow cytometry. As we hypothesized, positively charged COS-PLGA NPs and CS-PLGA NPs displayed enhanced intracellular uptake compared to negatively charged PLGA NPs. Our results demonstrated that CS- and COS-modified polymer NPs could be promising carriers for proteins, drugs and nucleic acids via nasal, oral, buccal, ocular and vaginal mucosal routes. PMID:27106502

  11. Stability improvement of electrospun chitosan nanofibrous membranes in neutral or weak basic aqueous solutions.

    Science.gov (United States)

    Sangsanoh, Pakakrong; Supaphol, Pitt

    2006-10-01

    Further utilization of chitosan nanofibrous membranes that are electrospun from chitosan solutions in trifluoroacetic acid (TFA) with or without dichloromethane (DCM) as the modifying cosolvent is limited by the loss of the fibrous structure as soon as the membranes are in contact with neutral or weak basic aqueous solutions due to complete dissolution of the membranes. Dissolution occurs as a result of the high solubility in these aqueous media of -NH(3)(+)CF(3)COO(-) salt residues that are formed when chitosan is dissolved in TFA. Traditional neutralization with a NaOH aqueous solution only maintained partial fibrous structure. Much improvement in the neutralization method was achieved with the saturated Na(2)CO(3) aqueous solution with an excess amount of Na(2)CO(3)(s) in the solution. We showed that electrospun chitosan nanofibrous membranes, after neutralization in the Na(2)CO(3) aqueous solution, could maintain its fibrous structure even after continuous submersion in phosphate buffer saline (pH = 7.4) or distilled water for 12 weeks. PMID:17025342

  12. Maize Mutant Opaque2 and the Improvement of Protein Quality through Conventional and Molecular Approaches

    International Nuclear Information System (INIS)

    Maize endosperm protein is deficient in two essential amino acids, lysine and tryptophan. Several spontaneous and induced mutations that affect amino acid composition in maize have been discovered, amongst which the opaque2 gene has been used in association with endosperm and amino acid modifier genes for developing quality protein maize (QPM), which contains almost double the amount of lysine and tryptophan compared to normal maize. These increases have been shown to have dramatic impacts on human and animal nutrition, growth and performance. A range of hard endosperm QPM germplasm has been developed at the International Maize and Wheat Improvement Center (CIMMYT) mostly through conventional breeding approaches to meet the requirements of various maize growing regions across the world. Microsatellite and SNP markers located within the opaque2 gene provide opportunities for accelerating the pace of QPM conversion programmes through marker-assisted selection (MAS). Thus, CIMMYT scientists are developing a package of reliable, easy-to-use markers for endosperm hardness and free amino acid content in the maize endosperm. Recent technological developments in molecular biology at CIMMYT such as single seed-based DNA extraction and low cost, high throughput SNP genotyping strategies promise enhanced efficiency and cost-effectiveness of QPM molecular breeding programmes. Here we present a summary of QPM research and breeding with respect to the history of conventional improvement methodologies, genetic and molecular basis of opaque2, epistasis between opaque2 and other high lysine mutant genes and recent advances in genomics technologies that could potentially enhance the efficiency of QPM molecular breeding in future. (author)

  13. Maize mutant opaque2 and the improvement of protein quality through conventional and molecular approaches

    International Nuclear Information System (INIS)

    Maize endosperm protein is deficient in two essential amino acids, lysine and tryptophan. Several spontaneous and induced mutations that affect amino acid composition in maize have been discovered amongst which the opaque2 gene has been used in association with endosperm and amino acid modifier genes for developing quality protein maize (QPM), which contains almost double the amount of lysine and tryptophan compared to normal maize. These increases have been shown to have dramatic impacts on human and animal nutrition, growth and performance, A range of hard endosperm QPM germplasm has been developed at the International Maize and Wheat Improvement Center (CIMMYT) mostly through conventional breeding approaches to meet the requirements of various maize growing regions across the world. Microsatellite markers located within the opaque2 gene provide opportunities for accelerating the pace of QPM conversion programs through marker-assisted selection (MAS). Thus, CIMMYT scientists are developing a package of reliable, easy to use markers for endosperm hardness and free amino acid content in the maize endosperm. Recent technological developments in molecular biology at CIMMYT such as single seed-based DNA extraction and low cost, high throughput SNP genotyping strategies promise enhanced efficiency and cost effectiveness of QPM molecular breeding programs. Here we present a summary of QPM research and breeding with respect to the history of conventional improvement methodologies, genetic and molecular basis of opaque2, epistasis between opaque2 and other high lysine mutant genes and recent advances in genomics technologies that could potentially enhance the efficiency of QPM molecular breeding in future. (author)

  14. Improved tolerance of maize (Zea mays L.) to heavy metals by colonization of a dark septate endophyte (DSE) Exophiala pisciphila

    International Nuclear Information System (INIS)

    Dark septate endophytes (DSE) are ubiquitous and abundant in stressful environments including heavy metal (HM) stress. However, our knowledge about the roles of DSE in improving HM tolerance of their host plants is poor. In this study, maize (Zea mays L.) was inoculated with a HM tolerant DSE strain Exophiala pisciphila H93 in lead (Pb), zinc (Zn), and cadmium (Cd) contaminated soils. E. pisciphila H93 successfully colonized and formed typical DSE structures in the inoculated maize roots. Colonization of E. pisciphila H93 alleviated the deleterious effects of excessive HM supplements and promoted the growth of maize (roots and shoots) under HM stress conditions, though it significantly decreased the biomass of inoculated maize under no HM stress. Further analysis showed that the colonization of E. pisciphila H93 improved the tolerance of maize to HM by restricting the translocation of HM ions from roots to shoots. This study demonstrated that under higher HM stress, such a mutual symbiosis between E. pisciphila and its host (maize) may be an efficient strategy to survive in the stressful environments. - Research Highlights: →Effect of DSE (E. pisciphila) on heavy metal tolerance of maize host was studied. →DSE alleviated the deleterious effect of excessive heavy metals on maize. →DSE restricted the transfer of heavy metals from the roots to shoots in maize. →DSE colonization improved the tolerance of their host plants to heavy metals.

  15. Improved tolerance of maize (Zea mays L.) to heavy metals by colonization of a dark septate endophyte (DSE) Exophiala pisciphila

    Energy Technology Data Exchange (ETDEWEB)

    Li, T.; Liu, M.J.; Zhang, X.T. [Key Laboratory of Conservation and Utilization for Bioresources, Yunnan University, Kunming, 650091 Yunnan (China); Zhang, H.B. [Key Laboratory of Conservation and Utilization for Bioresources, Yunnan University, Kunming, 650091 Yunnan (China); Department of Biology, Yunnan University, Kunming, 650091 Yunnan (China); Sha, T. [Key Laboratory of Conservation and Utilization for Bioresources, Yunnan University, Kunming, 650091 Yunnan (China); Zhao, Z.W., E-mail: zhaozhw@ynu.edu.cn [Key Laboratory of Conservation and Utilization for Bioresources, Yunnan University, Kunming, 650091 Yunnan (China)

    2011-02-15

    Dark septate endophytes (DSE) are ubiquitous and abundant in stressful environments including heavy metal (HM) stress. However, our knowledge about the roles of DSE in improving HM tolerance of their host plants is poor. In this study, maize (Zea mays L.) was inoculated with a HM tolerant DSE strain Exophiala pisciphila H93 in lead (Pb), zinc (Zn), and cadmium (Cd) contaminated soils. E. pisciphila H93 successfully colonized and formed typical DSE structures in the inoculated maize roots. Colonization of E. pisciphila H93 alleviated the deleterious effects of excessive HM supplements and promoted the growth of maize (roots and shoots) under HM stress conditions, though it significantly decreased the biomass of inoculated maize under no HM stress. Further analysis showed that the colonization of E. pisciphila H93 improved the tolerance of maize to HM by restricting the translocation of HM ions from roots to shoots. This study demonstrated that under higher HM stress, such a mutual symbiosis between E. pisciphila and its host (maize) may be an efficient strategy to survive in the stressful environments. - Research Highlights: {yields}Effect of DSE (E. pisciphila) on heavy metal tolerance of maize host was studied. {yields}DSE alleviated the deleterious effect of excessive heavy metals on maize. {yields}DSE restricted the transfer of heavy metals from the roots to shoots in maize. {yields}DSE colonization improved the tolerance of their host plants to heavy metals.

  16. Insect stings to change gear for healthy plant: Improving maize drought tolerance by whitefly infestation.

    Science.gov (United States)

    Park, Yong-Soon; Ryu, Choong-Min

    2016-05-01

    Since plants first appeared about 1.1 billion years ago, they have been faced with biotic and abiotic stresses in their environment. To overcome these stresses, plants developed defense strategies. Accumulating evidence suggests that the whitefly [Bemisia tabaci (Genn.)] affects the regulation of plant defenses and physiology. A recent study demonstrates that aboveground whitefly infestation positively modulates root biomass and anthocyanin pigmentation on brace roots of maize plants (Zea mays L.). In agreement with these observations, indole-3-acetic acid (IAA) and jasmonic acid (JA) contents and the expression of IAA- and JA-related genes are higher in whitefly-infested maize plants than in non-infected control plants. Interestingly, the fresh weight of whitefly-infested maize plants is approximately 20% higher than in non-infected control plants under water stress conditions. Further investigation has revealed that hydrogen peroxide (H2O2) accumulates in whitefly-infested maize plants after water stoppage. Taken together, these results suggest that activation of phytohormones- (i.e., IAA and JA) and H2O2-mediated maize signaling pathways triggered by aboveground whitefly infestation promotes drought resistance. They also provide an insight into how inter-kingdom interactions can improve drought tolerance in plants. PMID:27164447

  17. Seed priming improves early seedling vigor, growth and productivity of spring maize

    Institute of Scientific and Technical Information of China (English)

    Hafeez ur Rehman; Hassan Iqbal; Shahzad M A Basra; Irfan Afzal; Muhammad Farooq; Abdul Wakeel; WANG Ning

    2015-01-01

    Potential of seed priming treatments in improving the performance of early planted maize was evaluated against timely planting. Seeds of maize hybrid FH-810 were soaked in water (hydropriming), CaCl2 (2.2%, osmopriming), moringa leaf extracts (MLE 3.3%, osmopriming) and salicylic acid (SA, 50 mg L–1, hormonal priming) each for 18 h. Untreated and hydroprimed seeds were taken as control. Seeds primed with SA took less time in emergence and had high vigor in early planted maize. Amongst treatments, hormonal priming, reduced the electrical conductivity, increased the leaf relative and chlorophyl contents fol owed by osmopriming with CaCl2 at seedling stage. Likewise, plant height, grain rows and 1 000-grain weight, grain and biological yield and harvest index were also improved by seed priming;however hormonal priming and osmopriming with MLE were more effective in this regard. Improved yield performance by hormonal priming or osmopriming with MLE in early planting primarily owed to increased leaf area index, crop growth and net assimilation rates, and maintenance of green leaf area at maturity. In conclusion, osmopriming with MLE and hormonal priming with SA were the most economical treatments in improving productivity of early planted spring maize through stimulation of early seedling growth at low temperature.

  18. Seed priming improves early seedling vigor, growth and productivity of spring maize

    Institute of Scientific and Technical Information of China (English)

    Hafeez ur Rehman[1; Hassan lqbal[1; Shahzad M A Basra[1; Irfan Afzal[1; Muhammad Farooq[2; Abdul Wakeel[3; WANG Ning[4

    2015-01-01

    Potential of seed priming treatments in improving the performance of early planted maize was evaluated against timely planting. Seeds of maize hybrid FH-810 were soaked in water (hydropriming), CaCI2 (2.2%, osmopriming), moringa leaf extracts (MLE 3.3%, osmopriming) and salicylic acid (SA, 50 mg L-1, hormonal priming) each for 18 h. Untreated and hydroprimed seeds were taken as control. Seeds primed with SA took less time in emergence and had high vigor in eady planted maize. Amongst treatments, hormonal priming, reduced the electrical conductivity, increased the leaf relative and chlorophyll contents followed by osmopriming with CaCI2 at seedling stage. Likewise, plant height, grain rows and 1 000-grain weight, grain and biological yield and harvest index were also improved by seed pdming; however hormonal priming and osmopriming with MLE were more effective in this regard. Improved yield performance by hormonal priming or osmopriming with MLE in early planting primarily owed to increased leaf area index, crop growth and net assimilation rates, and maintenance of green leaf area at maturity. In conclusion, osmopriming with MLE and hormonal priming with SA were the most economical treatments in improving productivity of early planted spring maize through stimulation of early seedling growth at low temperature.

  19. The use of chitosan as bioadhesive and its property improvement by radiation treatment for water-stable shrimp feed production

    International Nuclear Information System (INIS)

    Among marine polysaccharides, only chitosan with small content in feed (0.48-0.75%) could be selected to prepare shrimp feed-pellet having so high water-stability that meet the Standard of Vietnam Ministry of Fisheries 28-TCN 102/1997. Solid-state radiation treatment of chitosan with dose ranging from 10 to 200 kGy not only increased its solubility in solvents of dilute acid, but also improved the water-stability of feed-pellet product. Radiation treatment at sterilization doses (20-40 kGy) was evaluated as the most practical technology because irradiated chitosan with reduced content of 0.34% has capacity to be prepared feed-pellets stable as comparable to imported products. Results from feeding trials shown that chitosan containing feed did not affect the growth response and feed utilization efficiency such as weight gain (WG), feed conversion ratio (FCR) and productivity at harvest. (author)

  20. The use of chitosan as bioadhesive and its property improvement by radiation treatment for water-stable shrimp feed production

    Energy Technology Data Exchange (ETDEWEB)

    Lam, Nguyen Duy; Hung, Nguyen Manh; Quynh, Tran Minh; Diep, Tran Bang; Binh, Nguen Van [Vietnam Atomic Energy Commission, Institute for Nuclear Science and Techniques, Caugiay, Hanoi (Viet Nam); Dung, Vu [Ministry of Fisheries, Research Institute of Marine Product, Haiphong (Viet Nam); Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2002-03-01

    Among marine polysaccharides, only chitosan with small content in feed (0.48-0.75%) could be selected to prepare shrimp feed-pellet having so high water-stability that meet the Standard of Vietnam Ministry of Fisheries 28-TCN 102/1997. Solid-state radiation treatment of chitosan with dose ranging from 10 to 200 kGy not only increased its solubility in solvents of dilute acid, but also improved the water-stability of feed-pellet product. Radiation treatment at sterilization doses (20-40 kGy) was evaluated as the most practical technology because irradiated chitosan with reduced content of 0.34% has capacity to be prepared feed-pellets stable as comparable to imported products. Results from feeding trials shown that chitosan containing feed did not affect the growth response and feed utilization efficiency such as weight gain (WG), feed conversion ratio (FCR) and productivity at harvest. (author)

  1. 3D chitosan-gelatin-chondroitin porous scaffold improves osteogenic differentiation of mesenchymal stem cells

    International Nuclear Information System (INIS)

    A porous 3D scaffold was developed to support and enhance the differentiation process of mesenchymal stem cells (MSC) into osteoblasts in vitro. The 3D scaffold was made with chitosan, gelatin and chondroitin and it was crosslinked by EDAC. The scaffold physicochemical properties were evaluated. SEM revealed the high porosity and interconnection of pores in the scaffold; rheological measurements show that the scaffold exhibits a characteristic behavior of strong gels. The elastic modulus found in compressive tests of the crosslinked scaffold was about 50 times higher than the non-crosslinked one. After 21 days, the 3D matrix submitted to hydrolytic degradation loses above 40% of its weight. MSC were collected from rat bone marrow and seeded in chitosan-gelatin-chondroitin 3D scaffolds and in 2D culture plates as well. MSC were differentiated into osteoblasts for 21 days. Cell proliferation and alkaline phosphatase activity were followed weekly during the osteogenic process. The osteogenic differentiation of MSC was improved in 3D culture as shown by MTT assay and alkaline phosphatase activity. On the 21st day, bone markers, osteopontin and osteocalcin, were detected by the PCR analysis. This study shows that the chitosan-gelatin-chondroitin 3D structure provides a good environment for the osteogenic process and enhances cellular proliferation

  2. Prosopis alba exudate gum as excipient for improving fish oil stability in alginate-chitosan beads.

    Science.gov (United States)

    Vasile, Franco Emanuel; Romero, Ana María; Judis, María Alicia; Mazzobre, María Florencia

    2016-01-01

    The aim of the present work was to employ an exudate gum obtained from a South American wild tree (Prosopis alba), as wall material component to enhance the oxidative stability of fish oil encapsulated in alginate-chitosan beads. For this purpose, beads were vacuum-dried and stored under controlled conditions. Oxidation products, fatty acid profiles and lipid health indices were measured during storage. Alginate-chitosan interactions and the effect of gum were manifested in the FT-IR spectra. The inclusion of the gum in the gelation media allowed decreasing the oxidative damage during storage in comparison to the free oil and alginate-chitosan beads. The gum also improved wall material properties, providing higher oil retention during the drying step and subsequent storage. Fatty acids quality and lipid health indices were widely preserved in beads containing the gum. Present results showed a positive influence of the gum on oil encapsulation and stability, being the main mechanism attributed to a physical barrier effect. PMID:26213081

  3. AN INITIAL INVESTIGATION OF THE POTENTIAL FOR HERMETIC PURDUE IMPROVED COWPEA STORAGE (PICS) BAGS TO IMPROVE INCOMES FOR MAIZE PRODUCERS IN SUB-SAHARAN AFRICA

    OpenAIRE

    Michael Jones; Corinne Alexander; James Lowenberg-DeBoer

    2011-01-01

    Pests like the larger grain borer (P. truncatus) and the maize weevil (S. zeamis) cause significant storage losses for African maize producers. The value of storage protection to a market-oriented farmer is a function of price seasonality, value loss prevention, and their opportunity costs of capital. Evidence suggests that hermetic technologies like Purdue Improved Crop Storage (PICS) bags can be effective against these key maize storage pests, but sustainable technology transfer requires th...

  4. Chitosan-Mediated shRNA Knockdown of Cytosolic Alanine Aminotransferase Improves Hepatic Carbohydrate Metabolism.

    Science.gov (United States)

    González, Juan D; Silva-Marrero, Jonás I; Metón, Isidoro; Caballero-Solares, Albert; Viegas, Ivan; Fernández, Felipe; Miñarro, Montserrat; Fàbregas, Anna; Ticó, Josep R; Jones, John G; Baanante, Isabel V

    2016-02-01

    Alanine aminotransferase (ALT) catalyses a transamination reaction that links carbohydrate and amino acid metabolism. In this study, we examined the effect of silencing cytosolic ALT (cALT) expression on the hepatic metabolism in Sparus aurata. A number of siRNA and shRNA designed to down-regulate cALT expression were validated in HEK-293 cells transfected with plasmids expressing S. aurata cALT or mitochondrial ALT (mALT) isoforms: ALT silencing significantly decreased the expression levels of S. aurata mRNA cALT1 to 62% (siRNA) and 48% (shRNA) of the values observed in control cells. The effect of cALT silencing was analysed in the liver of S. aurata 72 h after intraperitoneal injection of chitosan-tripolyphosphate (TPP) nanoparticles complexed with a plasmid encoding a shRNA to down-regulate cALT expression (pCpG-si1sh1). In fish fed diets with different ratio of protein to carbohydrate and treated with chitosan-TPP-pCpG-si1sh1, cALT1 and cALT2 mRNA levels significantly decreased irrespective of the diet. Consistently, ALT activity decreased in liver of treated animals. In the liver of S. aurata treated with chitosan-TPP-pCpG-si1sh1 nanoparticles, down-regulation of cALT expression increased the activity of key enzymes in glycolysis (6-phosphofructo-1-kinase and pyruvate kinase) and protein metabolism (glutamate dehydrogenase). Besides showing for the first time that administration of chitosan-TPP-pCpG-si1sh1 nanoparticles silences hepatic cALT expression in vivo, our data support that down-regulation of cALT could improve the use of dietary carbohydrates to obtain energy and spare protein catabolism. PMID:26475146

  5. Analysis of Participatory Research Projects in the International Maize and Wheat Improvement Center

    OpenAIRE

    Lilja, Nina K.; Bellon, Mauricio R.

    2006-01-01

    Through a survey of scientists from the International Maize and Wheat Improvement Center (CIMMYT) in 2004, this study assessed the extent to which participatory methods had been used by the center, how they were perceived by the scientists, and how participatory research could be applied more effectively by CIMMYT and partners. Results for 19 CIMMYT projects suggest among other things that participatory approaches at the center were largely “functional”—that is, aimed at improving the efficie...

  6. Chitosan Coagulation to Improve Microbial and Turbidity Removal by Ceramic Water Filtration for Household Drinking Water Treatment

    Directory of Open Access Journals (Sweden)

    Lydia S. Abebe

    2016-02-01

    Full Text Available The use of porous ceramic filters is promoted globally for household water treatment, but these filters are ineffective in removing viruses from water. In order to increase virus removal, we combine a promising natural coagulant, chitosan, as a pretreatment for ceramic water filters (CWFs and evaluate the performance of this dual barrier water treatment system. Chitosan is a non-toxic and biodegradable organic polymer derived by simple chemical treatments from chitin, a major source of which is the leftover shells of crustacean seafoods, such as shrimp, prawns, crabs, and lobsters. To determine the effectiveness of chitosan, model test water was contaminated with Escherichia coli K011 and coliphage MS2 as a model enteric bacterium and virus, respectively. Kaolinite clay was used to model turbidity. Coagulation effectiveness of three types of modified chitosans was determine at various doses ranging from 5 to 30 mg/L, followed by flocculation and sedimentation. The pre-treated supernatant water was then decanted into the CWF for further treatment by filtration. There were appreciable microbial removals by chitosan HCl, acetate, and lactate pretreatment followed by CWF treatment, with mean reductions (95% CI between 4.7 (±1.56 and 7.5 (±0.02 log10 for Escherichia coli, and between 2.8 (±0.10 and 4.5 (±1.04 log10 for MS2. Turbidity reduction with chitosan treatment and filtration consistently resulted in turbidities < 1 NTU, which meet turbidity standards of the US EPA and guidance by the World Health Organization (WHO. According to WHO health-based microbial removal targets for household water treatment technology, chitosan coagulation achieved health protective targets for both viruses and bacteria. Therefore, the results of this study support the use of chitosan to improve household drinking water filtration processes by increasing virus and bacteria reductions.

  7. Chitosan Coagulation to Improve Microbial and Turbidity Removal by Ceramic Water Filtration for Household Drinking Water Treatment

    Science.gov (United States)

    Abebe, Lydia S.; Chen, Xinyu; Sobsey, Mark D.

    2016-01-01

    The use of porous ceramic filters is promoted globally for household water treatment, but these filters are ineffective in removing viruses from water. In order to increase virus removal, we combine a promising natural coagulant, chitosan, as a pretreatment for ceramic water filters (CWFs) and evaluate the performance of this dual barrier water treatment system. Chitosan is a non-toxic and biodegradable organic polymer derived by simple chemical treatments from chitin, a major source of which is the leftover shells of crustacean seafoods, such as shrimp, prawns, crabs, and lobsters. To determine the effectiveness of chitosan, model test water was contaminated with Escherichia coli K011 and coliphage MS2 as a model enteric bacterium and virus, respectively. Kaolinite clay was used to model turbidity. Coagulation effectiveness of three types of modified chitosans was determine at various doses ranging from 5 to 30 mg/L, followed by flocculation and sedimentation. The pre-treated supernatant water was then decanted into the CWF for further treatment by filtration. There were appreciable microbial removals by chitosan HCl, acetate, and lactate pretreatment followed by CWF treatment, with mean reductions (95% CI) between 4.7 (±1.56) and 7.5 (±0.02) log10 for Escherichia coli, and between 2.8 (±0.10) and 4.5 (±1.04) log10 for MS2. Turbidity reduction with chitosan treatment and filtration consistently resulted in turbidities technology, chitosan coagulation achieved health protective targets for both viruses and bacteria. Therefore, the results of this study support the use of chitosan to improve household drinking water filtration processes by increasing virus and bacteria reductions. PMID:26927152

  8. Efficiency of mineral fertilizers and mucuna on the improvement of the yield of maize in zimbabwe

    International Nuclear Information System (INIS)

    In Zimbabwe farmers use sub-optimal amounts of fertilizers due to cash limitations and poor access to fertilizer markets, hence the need to integrate legumes like mucuna (Mucuna pruriens) into their cropping systems. In this study, the effect of P and N along with different mucuna management options was investigated on the yield and yield components of maize. The experimental design was a split - split- plot with two P rates (0 and 40 kg P ha/sup -1/) applied to a preceding mucuna crop, four mucuna management options 1) fallow (F), 2) mucuna ploughed in at flowering (MF), 3) all mucuna above ground biomass removed at maturity and only roots were ploughed in (MAR) and 4) mucuna pods removed and the residues ploughed in (MPR 3 and four N treatments (N0 = 0, N1 =40, N2 = 80 and N3 = 120 kg N ha/sup -1/ respectively) applied to a subsequent maize crop. The various crop parameters like grain yield, cob length, number of grains per cob, cob diameter, 1000 dry grain weight, stalk weight and harvest index of maize were determined. Phosphorous application improved mean maize grain yield from 2.29 t ha/sup -1/ to 2.34 t ha/sup -1/. The MF and N3 treatment combination resulted in the highest maize grain yield. The MF and MPR and N0 treatment combinations resulted in similar grain yields when compared with F and MAR management options and N3. Other parameters followed similar trends. The MF and MPR management options could, therefore, save 80 and 120 kg N ha/sup -1/for smallholder farmers without sacrificing yield. (author)

  9. Farm technology adoption in Kenya: A simultaneous estimation of inorganic fertilizer and improved maize variety adoption decisions

    OpenAIRE

    Ogada, Maurice J.; Mwabu, Germano; Muchai, Diana

    2014-01-01

    This paper models inorganic fertilizer and improved maize varieties adoption as joint decisions. Controlling for household, plot-level, institutional and other factors, the study found that household adoption decisions on inorganic fertilizer and improved maize varieties were inter-dependent. Other factors found to influence the adoption of the two technologies were farmer characteristics, plot-level factors and market imperfections such as limited access to credit and input markets, and prod...

  10. Silicon induced improvement in morpho-physiological traits of maize (zea mays l.) under water deficit

    International Nuclear Information System (INIS)

    Current water scarcity is an emerging issue in semi-arid regions like Pakistan and cause of deterioration in productivity of crops to reduce crop yield all over the world. Silicon is known to be better against the deleterious effects of drought on plant growth and development. A pot study was conducted to evaluate the effect of Si nutrition (0, 50, 100 and 150 mg/kg) on the growth of a relatively drought tolerant (P-33H25) and sensitive (FH-810) maize hybrids. Two levels of soil water content were used viz. 100 and 60% of field capacity. Water deficit condition in soil significantly reduced morphological and physiological attributes of maize plants. Silicon application significantly improved the plant height, leaf area per plant, primary root length, dry matter of shoot and roots and plant dry matter, water relation and gas exchange characteristics of both maize cultivars under water deficit condition. Poor growth of drought stressed plants was significantly improved with Si application. The silicon fertilized (100 mg/kg) drought stressed plants of hybrid P-33H25 produced maximum (21.68% more) plant dry matter as compared to plants that were not provided with silicon nutrition. Nonetheless, silicon application (150 mg/kg) resulted in maximum increase (26.03%) in plant dry weight of hybrid FH-810 plants that were grown under limited moisture supply i.e., 60% FC. In conclusion silicon application to drought stressed maize plants was better to improve the growth and dry matter could be attributed to improved osmotic adjustment, photosynthetic rate and lowered transpiration. (author)

  11. "Bio-glues" to Enhance Slipperiness of Mucins: Improved Lubricity and Wear Resistance of Porcine Gastric Mucin (PGM) Layers Assisted by Mucoadhesion with Chitosan

    DEFF Research Database (Denmark)

    Nikogeorgos, Nikolaos; Efler, Petr; Lee, Seunghwan;

    2015-01-01

    A synergetic lubricating effect between porcine gastric mucin (PGM) and chitosan based on their mucoadhesive interaction is reported at a hydrophobic interface comprised of self-mated polydimethylsiloxane (PDMS) surfaces. In acidic solution (pH 3.2) and low concentrations (0.1 mg mL- 1), the...... interaction of PGM with chitosan led to surface recharge and size shrinkage of their aggregates. This resulted in higher mass adsorption on the PDMS surface with increasing weight ratio of [chitosan]/[PGM + chitosan] up to 0.50. While neither PGM nor chitosan exhibited slippery characteristics, coefficient of...... friction being close to 1, their mixture improved considerably the lubricating efficiency (coefficient of friction 0.011 at optimum mixing ratio) and wear resistance of the adsorbed layers. These findings are explained by the role of chitosan as a physical crosslinker within the adsorbed PGM layers...

  12. The effects of improved maize technology on household welfare in Buruku, Benue State, Nigeria

    Directory of Open Access Journals (Sweden)

    Victoria I. Audu

    2014-12-01

    Full Text Available This study was carried out to determine the welfare effects of improved maize technology in Buruku Local Government Area of Benue State, Nigeria. The study also examined the determinants of the adoption of improved maize technology. Structured questionnaires were used in collecting the primary data for the study. A multi-stage random technique was used in selecting 125 farm households for the study. The Logit and ordinary least square (OLS models were used in analyzing the data. The OLS results show that adoption of improved maize varieties is positively and significantly related to household welfare and thus has contributed to moving farm households out of poverty. Other variables found to be statistically significant in explaining household welfare are education, household size, and landholding. The Logit results show that age, household size, off-farm income, and education were found to be significant in influencing farmers’ adoption decisions. Some robustness checks were performed with different specifications of the Logit and OLS models as well as re-estimation with propensity matching score approach. Overall, the results are robust to different specifications.

  13. Immobilization of papaya laccase in chitosan led to improved multipronged stability and dye discoloration.

    Science.gov (United States)

    Jaiswal, Nivedita; Pandey, Veda P; Dwivedi, Upendra N

    2016-05-01

    A purified papaya laccase was immobilized in chitosan beads using entrapment approach and its physico-chemical properties were investigated and compared with that of free enzyme. Increase in properties of the laccase such as optimum temperature (by 10°C), thermostability (by 3-folds) and optimum pH (from 8.0 to 10.0) was observed after immobilization. Immobilization led to increased tolerance of enzyme to a number of metal ions (including heavy metals) and organic solvents namely, ethanol, isopropanol, methanol, benzene and DMF. The catalytic efficiency (Kcat/Km) of the immobilized enzyme was found to increase more than ten folds, in comparison to that of the free enzyme, with hydroquinone as substrate. Immobilization of laccase also led to improvement in dye decolorization such that the synthetic dye indigo carmine (50μg/ml) was completely decolorized within 8h of incubation as compared to that of the free laccase which decolorized the same dye to only 56% under similar conditions. Thus, immobilization of laccase into chitosan beads led to tremendous improvement in various useful attributes of this enzyme thereby making it more versatile for its industrial exploitation. PMID:26812115

  14. Improved postharvest quality in patagonian squash (Cucurbita moschata) coated with radiation depolymerized chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Pugliese, Maria Alicia; Goitia, Maria Teresa [Laboratorio de Investigaciones Basicas Aplicadas en Quitina, Departamento de Quimica, Universidad Nacional del Sur. Avenida Alem 1253, B8000CPB Bahia Blanca (Argentina); Yossen, Mariana [Instituto de Desarrollo Tecnologico para la Industria Quimica (INTEC), CONICET-Universidad Nacional del Litoral, Ruta Nacional 168-Paraje ' El Pozo' , 3000 Santa Fe (Argentina); Cifone, Norma; Agullo, Enrique [Laboratorio de Investigaciones Basicas Aplicadas en Quitina, Departamento de Quimica, Universidad Nacional del Sur. Avenida Alem 1253, B8000CPB Bahia Blanca (Argentina); Andreucetti, Noemi, E-mail: andreuce@criba.edu.ar [Laboratorio de Radioisotopos, Departamento de Quimica, Universidad Nacional del Sur, Avenida Alem 1253, B8000CPB Bahia Blanca (Argentina)

    2011-12-15

    Different molecular weight chitosans were evaluated on the decay of coated Anquito squashes (Cucurbita moschata) as well as the maintenance of the fruit quality along five storage months. The original chitosan (Mw=391 kDa, 83% DD), was depolymerized by gamma radiation. Apart from chain scission, other chemical changes were not detected by FTIR or UV-vis analyses. The molecular weight characterization of chitosans was done by size exclusion chromatography with dual light scattering and concentration detection (SEC-MALLS-RI). The coating effectiveness was evaluated on the following parameters: fungal decay incidence, weight loss, firmness, total reducing sugar, soluble solid, flesh color, carotene content, pH and titratable acidity. No sign of fungal decay was observed in squashes coated with 122 and 56 kDa chitosans, which were also the most effective treatments in reducing the weight loss. The chitosan with Mw=122 kDa was also the best treatment considering firmness, internal aspect, sugar and carotene content. Then, radiation degraded chitosan was better in C. moschata preservation than the original chitosan. - Highlights: > Original Chitosan was radiation depolymerized producing chitosans with lower molecular weights. > Gamma-irradiated chitosans only exhibit chain scission. > SEC-MALLS-RI chromatography is a useful tool in molecular weight analysis. > Depolymerized chitosans were the best in maintaining the quality and the storage life of coated squashes.

  15. Improved neutron capture technique for nitrogen determination in single maize seeds

    International Nuclear Information System (INIS)

    Improvements to increase the sensitivity of nitrogen determination in single maize seeds were carried out using the capture gamma rays from the 14N(n,gamma)15N prompt reaction. By background and pile up reductions using geometrical, shielding and electronic considerations, a relative nitrogen determination error of 11% was achieved at a 95% confidence level for typical maize seeds (3 mg nitrogen, 200 mg mass) at 60 s measurement time, i.e. a relatively fast 1440 sample per day capacity could be reached in nondestructive seed selection for crude protein. At an analysis speed of 450 single seed/day simple automatic systems at the High Flux Reactor, Grenoble, France, were constructed and used to scan the crude protein distribution of single seed populations. (author)

  16. Phenotypic recurrent selection to improve protein quality in non-opaque maize populations

    Directory of Open Access Journals (Sweden)

    Garcia Antonio Augusto Franco

    2002-01-01

    Full Text Available Maize (Zea mays L. protein is considered to be of low quality due to low levels of the essential lysine and tryptophan amino acids. An alternative to solve this problem is to use the opaque-2 gene, which improves the level of these amino acids, but has negative pleiotropic effects on agronomic characters. A phenotypic recurrent selection scheme was carried out in two non-opaque maize populations to verify the possibility of improving their protein quality without using this gene. Four cycles were completed and a 20% selection intensity for tryptophan content in the kernels was used in two populations, IG-1 and IG-2. The original and the four-cycle populations were evaluated in three locations for agronomic traits. For protein and tryptophan content, a separated trial was carried out because plants of the plots were hand-pollinated. No increase in tryptophan content was observed in the IG-2 population, whereas IG-1 presented a small increase (0.70% per cycle. The ratio tryptophan/protein increased 1.26% per cycle in IG-1 and the protein content did not increase in both populations. The ESALQ-VD2-opaque check was superior in relation to both populations for protein quality, as expected, even after completion of four selection cycles. The kernel yield (2.5% per cycle prolificacy, plant and ear heights, decreased with selection cycles, as a correlated response to selection. Phenotypic recurrent selection in non-opaque maize was not able to increase, at reasonable rates, the protein quality of maize kernels.

  17. Amendment of Tephrosia Improved Fallows with Inorganic Fertilizers Improves Soil Chemical Properties, N Uptake, and Maize Yield in Malawi

    Directory of Open Access Journals (Sweden)

    Maggie G. Munthali

    2014-01-01

    Full Text Available Maize production in Malawi is limited mainly by low soil N and P. Improved fallows of N-fixing legumes such as Tephrosia and Sesbania offer options for improving soil fertility particularly N supply. The interactions of Tephrosia fallows and inorganic fertilizers on soil properties, N uptake, and maize yields were evaluated at Chitedze Research Station in Malawi. The results indicated that the level of organic matter and pH increased in all the treatments except for the control. Total N remained almost unchanged while available P decreased in all plots amended with T. vogelii but increased in T. candida plots where inorganic P was applied. Exchangeable K increased in all the plots irrespective of the type of amendment. The interaction of N and P fertilizers with T. vogelii fallows significantly increased the grain yield. The treatment that received 45 kg N ha−1 and 20 kg P ha−1 produced significantly higher grain yields (6.8 t ha−1 than all the other treatments except where 68 kg N ha−1 and 30 kg P ha−1 were applied which gave 6.5 t ha−1 of maize grain. T. candida fallows alone or in combination with N and P fertilizers did not significantly affect grain yield. However, T. candida fallows alone can raise maize grain yield by 300% over the no-input control. Based on these results we conclude that high quality residues such as T. candida and T. vogelii can be used as sources of nutrients to improve crop yields and soil fertility in N-limited soils. However, inorganic P fertilizer is needed due to the low soil available P levels.

  18. Chitosan Coated Textiles May Improve Atopic Dermatitis Severity by Modulating Skin Staphylococcal Profile: A Randomized Controlled Trial

    Science.gov (United States)

    Lopes, Cristina; Soares, Jose; Tavaria, Freni; Duarte, Ana; Correia, Osvaldo; Sokhatska, Oksana; Severo, Milton; Silva, Diana; Pintado, Manuela; Delgado, Luis; Moreira, Andre

    2015-01-01

    Background Atopic dermatitis (AD) patients may benefit from using textiles coated with skin microbiome–modulating compounds. Chitosan, a natural biopolymer with immunomodulatory and antimicrobial properties, has been considered potentially useful. Objective This randomized controlled trial assessed the clinical utility of chitosan-coated garment use in AD. Methods Of the 102 patients screened, 78 adult and adolescents were randomly allocated to overnight use of chitosan-coated or uncoated cotton long-sleeved pyjama tops and pants for 8 weeks. The primary outcome was change in disease severity assessed by Scoring Atopic dermatitis index (SCORAD). Other outcomes were changes in quality of life, pruritus and sleep loss, days with need for rescue medication, number of flares and controlled weeks, and adverse events. Changes in total staphylococci and Staphylococcus aureus skin counts were also assessed. Comparisons were made using analysis of variance supplemented by repeated measures analysis for the primary outcome. Interaction term between time and intervention was used to compare time trends between groups. Results Chitosan group improved SCORAD from baseline in 43.8%, (95%CI: 30.9 to 55.9), P = 0.01, placebo group in 16.5% (-21.6 to 54.6); P = 0.02 with no significant differences between groups; Dermatology Quality of life Index Score significantly improved in chitosan group (P = 0.02) and a significant increase of skin Coagulase negative Staphylococci (P = 0.02) was seen. Conclusions Chitosan coated textiles may impact on disease severity by modulating skin staphylococcal profile. Moreover, a potential effect in quality of life may be considered. Trial Registration ClinicalTrials.gov NCT01597817 PMID:26618557

  19. Seed priming with chitosan improves the germination and growth performance of ajowan

    Directory of Open Access Journals (Sweden)

    Batool Mahdavi

    2013-11-01

    Full Text Available Background: Chitosan is a polysaccharide biopolymer derived from chitin. It not only stimulates growth and increases the crop yields but also alleviates the harmful effect of abiotic stress on plant growth. The objective of this study was to investigate the effects of chitosan on germination and growth of ajowan (Carum copticum under salt stress. This study was conducted in a laboratory and greenhouse. Material and Methods: In the first experiment seed germination of ajowan monitored under seed pre-treated by soaking in chitosan solutions of 0, 0.01%, 0.05%, 0.1%, 0.2% and 0.5% for 3 h. In second experiment, seeds soaked in chitosan solutions (0 and 0.2% and sown in pots at different salinity levels (0, 4, 8 and 12 dS/m. Results: Results indicated that all of chitosan concentrations increased germination percentage, germination rate, seedling vigour index, length and dry weight of hypocotyl and radicle compared to control although, 0.2% chitosan concentration was more effective than other treatments. Salinity caused a significant reduction in germination percentage, shoot length, root length, shoot and root dry weight and relative water content, while chitosan adjusted the salt toxicity. Conclusions: It is concluded that chitosan would be able to stimulate germination and growth of ajowan. It is also resulted that soaking ajowan seeds with chitosan, may alleviate the inhibitory effect of salt stress on the plant growth.

  20. Improved tolerance of maize (Zea mays L.) to heavy metals by colonization of a dark septate endophyte (DSE) Exophiala pisciphila.

    Science.gov (United States)

    Li, T; Liu, M J; Zhang, X T; Zhang, H B; Sha, T; Zhao, Z W

    2011-02-15

    Dark septate endophytes (DSE) are ubiquitous and abundant in stressful environments including heavy metal (HM) stress. However, our knowledge about the roles of DSE in improving HM tolerance of their host plants is poor. In this study, maize (Zea mays L.) was inoculated with a HM tolerant DSE strain Exophiala pisciphila H93 in lead (Pb), zinc (Zn), and cadmium (Cd) contaminated soils. E. pisciphila H93 successfully colonized and formed typical DSE structures in the inoculated maize roots. Colonization of E. pisciphila H93 alleviated the deleterious effects of excessive HM supplements and promoted the growth of maize (roots and shoots) under HM stress conditions, though it significantly decreased the biomass of inoculated maize under no HM stress. Further analysis showed that the colonization of E. pisciphila H93 improved the tolerance of maize to HM by restricting the translocation of HM ions from roots to shoots. This study demonstrated that under higher HM stress, such a mutual symbiosis between E. pisciphila and its host (maize) may be an efficient strategy to survive in the stressful environments. PMID:21195456

  1. Chitosan/poly (vinyl pyrollidone) coatings improve the antibacterial properties of poly(ethylene terephthalate)

    Science.gov (United States)

    Wang, Bai-liang; Wang, Jin-lei; Li, Dan-dan; Ren, Ke-feng; Ji, Jian

    2012-08-01

    Chitosan/poly (vinyl pyrollidone) (CHI/PVP) coatings were prepared to improve the antibacterial properties of poly (ethylene terephthalate) (PET) by a simple dip-coating method. The binding capability of CHI/PVP coatings was enhanced by successively pretreatment of PET by polyetherimide and polyacrylic acid and crosslinking. Measurements of water contact angle and atomic force microscope revealed that the coatings created a highly hydrophilic surface with low roughness. Adherences of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) on PET with CHI/PVP coating were significantly reduced. Bactericidal activity of CHI/PVP coatings was good against E. coli and S. aureus and the adding of PVP obviously increased its antiadhesion property. In vitro cytotoxicity tests, cell morphology and activity evaluation of human umbilical vein endothelial cells showed that CHI/PVP coatings had good biocompatibility.

  2. Chitosan/poly (vinyl pyrollidone) coatings improve the antibacterial properties of poly(ethylene terephthalate)

    International Nuclear Information System (INIS)

    Chitosan/poly (vinyl pyrollidone) (CHI/PVP) coatings were prepared to improve the antibacterial properties of poly (ethylene terephthalate) (PET) by a simple dip-coating method. The binding capability of CHI/PVP coatings was enhanced by successively pretreatment of PET by polyetherimide and polyacrylic acid and crosslinking. Measurements of water contact angle and atomic force microscope revealed that the coatings created a highly hydrophilic surface with low roughness. Adherences of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) on PET with CHI/PVP coating were significantly reduced. Bactericidal activity of CHI/PVP coatings was good against E. coli and S. aureus and the adding of PVP obviously increased its antiadhesion property. In vitro cytotoxicity tests, cell morphology and activity evaluation of human umbilical vein endothelial cells showed that CHI/PVP coatings had good biocompatibility.

  3. Preparation of aminated chitosan/alginate scaffold containing halloysite nanotubes with improved cell attachment.

    Science.gov (United States)

    Amir Afshar, Hamideh; Ghaee, Azadeh

    2016-10-20

    The chemical nature of biomaterials play important role in cell attachment, proliferation and migration in tissue engineering. Chitosan and alginate are biodegradable and biocompatible polymers used as scaffolds for various medical and clinical applications. Amine groups of chitosan scaffolds play an important role in cell attachment and water adsorption but also associate with alginate carboxyl groups via electrostatic interactions and hydrogen bonding, consequently the activity of amine groups in the scaffold decreases. In this study, chitosan/alginate/halloysite nanotube (HNTs) composite scaffolds were prepared using a freeze-drying method. Amine treatment on the scaffold occurred through chemical methods, which in turn caused the hydroxyl groups to be replaced with carboxyl groups in chitosan and alginate, after which a reaction between ethylenediamine, 1-ethyl-3,(3-dimethylaminopropyl) carbodiimide (EDC) and scaffold triggered the amine groups to connect to the carboxyl groups of chitosan and alginate. The chemical structure, morphology and mechanical properties of the composite scaffolds were investigated by FTIR, CHNS, SEM/EDS and compression tests. The electrostatic attraction and hydrogen bonding between chitosan, alginate and halloysite was confirmed by FTIR spectroscopy. Chitosan/alginate/halloysite scaffolds exhibit significant enhancement in compressive strength compared with chitosan/alginate scaffolds. CHNS and EDS perfectly illustrate that amine groups were effectively introduced in the aminated scaffold. The growth and cell attachment of L929 cells as well as the cytotoxicity of the scaffolds were investigated by SEM and Alamar Blue (AB). The results indicated that the aminated chitosan/alginate/halloysite scaffold has better cell growth and cell adherence in comparison to that of chitosan/alginate/halloysite samples. Aminated chitosan/alginate/halloysite composite scaffolds exhibit great potential for applications in tissue engineering, ideally in

  4. Potential of Using Manure to Improve Soil Fertility in A Maize/Bean Intercrop in the Drylands

    International Nuclear Information System (INIS)

    Low soil fertility as a limiting factor in maize and bean production in ASALS areas is a pertinent topic for investigation, owing to the importance of the crops as staple foods as well as sources of income and employment for the increasing population occasioned by high fertility rates and immigration from the congested high potential highlands. The use of readily available and cheaper sources of plant nutrients such as farm yard manure (FYM), under the common practice of intercropping is one way of sustaining agricultural production in the drylands. The objective of the study conducted in LM5 (under irrigation) and LM5 (under rainfed) Agro-ecological zones of Baringo district was to determine the potential of use FYM and bean intercropping to improve soil fertility for higher maize yields. The result showed that under maize pure stand the highest yields of 3.2 tons/ha were obtained under DAP though this was not significantly different with FYM, FYM+CAN and No Fertilizer treatments. Under intercrop the highest maize yields of 2.8 t/ha were obtained under FYM+CAN. Economic analysis showed that bean pure stand system gave the highest result net benefits followed by intercrop and lastly maize pure stand. The result further showed that the generally low crop yield coupled by low prices renders Katumani maize variety uneconomical to be grown under irrigation and that the higher yielding hybrids (eg H513 using FYM+CAN could be more profitable to farmers in both zones)

  5. Reduced crown root number improves water acquisition under water deficit stress in maize (Zea mays L.).

    Science.gov (United States)

    Gao, Yingzhi; Lynch, Jonathan P

    2016-08-01

    In this study we test the hypothesis that maize genotypes with reduced crown root number (CN) will have greater root depth and improved water acquisition from drying soil. Maize recombinant inbred lines with contrasting CN were evaluated under water stress in greenhouse mesocosms and field rainout shelters. CN varied from 25 to 62 among genotypes. Under water stress in the mesocosms, genotypes with low CN had 31% fewer crown roots, 30% deeper rooting, 56% greater stomatal conductance, 45% greater leaf CO2 assimilation, 61% net canopy CO2 assimilation, and 55% greater shoot biomass than genotypes with high CN at 35 days after planting. Under water stress in the field, genotypes with low CN had 21% fewer crown roots, 41% deeper rooting, 48% lighter stem water oxygen isotope enrichment (δ(18)O) signature signifying deeper water capture, 13% greater leaf relative water content, 33% greater shoot biomass at anthesis, and 57% greater yield than genotypes with high CN. These results support the hypothesis that low CN improves drought tolerance by increasing rooting depth and water acquisition from the subsoil. PMID:27401910

  6. Nanoencapsulation of Red Ginseng Extracts Using Chitosan with Polyglutamic Acid or Fucoidan for Improving Antithrombotic Activities.

    Science.gov (United States)

    Kim, Eun Suh; Lee, Ji-Soo; Lee, Hyeon Gyu

    2016-06-15

    The potential of nanoencapsulation using bioactive coating materials for improving antithrombotic activities of red ginseng extract (RG) was examined. RG-loaded chitosan (CS) nanoparticles were prepared using antithrombotic materials, polyglutamic acid (PGA) or fucoidan (Fu). Both CS-PGA (P-NPs, 360 ± 67 nm) and CS-Fu nanoparticles (F-NPs, 440 ± 44 nm) showed sustained ginsenoside release in an acidic environment and improved ginsenoside solubility by approximately 122.8%. Both in vitro rabbit and ex vivo rat platelet aggregation of RG (22.3 and 41.5%) were significantly (p < 0.05) decreased within P-NPs (14.4 and 30.0%) and F-NPs (12.3 and 30.3%), respectively. Although RG exhibited no effect on in vivo carrageenan-induced mouse tail thrombosis, P-NPs and F-NPs demonstrated significant effects, likely the anticoagulation activity of PGA and Fu. Moreover, in the in vivo rat arteriovenous shunt model, P-NPs (156 ± 6.8 mg) and F-NPs (160 ± 3.2 mg) groups showed significantly lower thrombus formation than that of RG (190 ± 5.5 mg). Therefore, nanoencapsulation using CS, PGA, and Fu is a potential for improving the antithrombotic activity of RG. PMID:27181678

  7. Improved postharvest quality in patagonian squash ( Cucurbita moschata) coated with radiation depolymerized chitosan

    Science.gov (United States)

    Pugliese, Maria Alicia; Goitia, Maria Teresa; Yossen, Mariana; Cifone, Norma; Agulló, Enrique; Andreucetti, Noemi

    2011-12-01

    Different molecular weight chitosans were evaluated on the decay of coated Anquito squashes ( Cucurbita moschata) as well as the maintenance of the fruit quality along five storage months. The original chitosan (Mw=391 kDa, 83% DD), was depolymerized by gamma radiation. Apart from chain scission, other chemical changes were not detected by FTIR or UV-vis analyses. The molecular weight characterization of chitosans was done by size exclusion chromatography with dual light scattering and concentration detection (SEC-MALLS-RI). The coating effectiveness was evaluated on the following parameters: fungal decay incidence, weight loss, firmness, total reducing sugar, soluble solid, flesh color, carotene content, pH and titratable acidity. No sign of fungal decay was observed in squashes coated with 122 and 56 kDa chitosans, which were also the most effective treatments in reducing the weight loss. The chitosan with Mw=122 kDa was also the best treatment considering firmness, internal aspect, sugar and carotene content. Then, radiation degraded chitosan was better in C. moschata preservation than the original chitosan.

  8. Characterization of Chitosan Nanofiber Sheets for Antifungal Application

    OpenAIRE

    Mayumi Egusa; Ryo Iwamoto; Hironori Izawa; Minoru Morimoto; Hiroyuki Saimoto; Hironori Kaminaka; Shinsuke Ifuku

    2015-01-01

    Chitosan produced by the deacetylation of chitin is a cationic polymer with antimicrobial properties. In this study, we demonstrate the improvement of chitosan properties by nanofibrillation. Nanofiber sheets were prepared from nanofibrillated chitosan under neutral conditions. The Young’s modulus and tensile strength of the chitosan NF sheets were higher than those of the chitosan sheets prepared from dissolving chitosan in acetic acid. The chitosan NF sheets showed strong mycelial growth in...

  9. Strategies to improve the aging, barrier and mechanical properties of chitosan, whey and wheat gluten protein films

    OpenAIRE

    Olabarrieta, Idoia

    2005-01-01

    Chitosan, Whey Protein Isolate (WPI) and vital wheat gluten (WG) are three biomaterials that have quite promising properties for packaging purposes. They have good film forming properties and good gas barrier properties in dry conditions. Moreover, because they are produced from industrial waste of food processing, they offer an ecological advantage over polymers made from petroleum. However, their physicochemical characteristics still must be improved for them to be of commercial interest fo...

  10. Grain and tortilla quality in landraces and improved maize grown in the highlands of Mexico.

    Science.gov (United States)

    Vázquez-Carrillo, Gricelda; García-Lara, Silverio; Salinas-Moreno, Yolanda; Bergvinson, David J; Palacios-Rojas, Natalia

    2011-06-01

    The maize produced in the highlands of Mexico (>2,400 masl) is generally not accepted by the flour and masa and tortilla industry. The objective of this work was to evaluate the grain quality and tortilla properties of maize landraces commonly grown in the highlands of Mexico and compare them with improved germplasm (hybrids). Germplasm analysis included 11 landraces, 32 white hybrids, and six yellow hybrids. Grain quality was analyzed for a range of physical and chemical factors, as well as for alkaline cooking quality. Landrace grains tended to be heterogeneous in terms of size, hardness and color. All landraces had soft-intermediate grains with an average flotation index (FI) of 61%. In contrast, hybrid grains were homogenous in size and color, and harder than landrace grains, with a FI of 38%. Protein, free sugars, oil and phenolic content in landraces were higher than in the hybrids. Significant correlations were found between phenolic content and tortilla color (r= -0.60; ptortilla industry, while all the hybrids evaluated fulfilled the requirements of this industry. PMID:21611770

  11. Kinetics of phosphorus uptake and root morphology of local and improved varieties of maize

    Directory of Open Access Journals (Sweden)

    Machado Cynthia Torres de Toledo

    2004-01-01

    Full Text Available Interspecific and intraspecific differences in the efficiency of utilization of soil phosphorus (P are explained, in part, by plant morphological and physiological variations, which characterize the plant for nutrient acquisition. As part of a study on maize genotypes characterization for P-uptake and use efficiency, kinetic parameters of P uptake and root morphological characters were evaluated for six local and improved maize varieties, grown in nutrient solution. The kinetic parameters related to P influx were: maximal transport rate (Vmax, the Michaelis-Menten constant (Km, and the external concentration when net uptake is zero (Cmin. Measured root morphological characters were: root length, radius, and surface area. Shoot and root dry matter yield and the P content in these parts were also determined. Diferences among varieties were observed in the kinetic parameters Vmax and Km, root length and in root/shoot dry matter ratio. Lower Km values were better indicatives of P uptake ability of the varietes and were significantly correlated to higher dry matter production and P-efficiency index.

  12. Survey of Genomics Approaches to Improve Bioenergy Traits in Maize, Sorghum and Sugarcane

    Institute of Scientific and Technical Information of China (English)

    Wilfred Vermerris

    2011-01-01

    Bioenergy crops currently provide the only source of alternative energy with the potential to reduce the use of fossil transportation fuels in a way that is compatible with existing engine technology, including in developing countries. Even though bioenergy research is currently receiving considerable attention, many of the concepts are not new,but rather build on intense research efforts from 30 years ago. A major difference with that era is the availability of genomics tools that have the potential to accelerate crop improvement significantly. This review is focused on maize, sorghum and sugarcane as representatives of bioenergy grasses that produce sugar and/or lignocellulosic biomass.Examples of how genetic mapping, forward and reverse genetics, high-throughput expression profiling and comparative genomics can be used to unravel and improve bioenergy traits will be presented.

  13. Genetic Improvement of Root Growth Contributes to Efficient Phosphorus Acquisition in maize (Zea mays L.)

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yi-kai; CHEN Fan-jun; CHEN Xiao-chao; LONG Li-zhi; GAO Kun; YUAN Li-xing; ZHANG Fu-suo; MI Guo-hua

    2013-01-01

    Maize plants adapt to low phosphorus (P) stress by increasing root growth. It is of importance to know the extent to which genetic improvement of root growth can enhance P acquisiton. In the present study, the contribution of root growth improvement to efficient P acquisition was evaluated in two soils using T149 and T222, a pair of near isogenic maize testcrosses which were derived from a backcross BC4F3 population. T149 and T222 showed no difference in shoot biomass and leaf area under normal growth conditions, but differed greatly in root growth. T149 had longer lateral roots and a larger root surface area compared to T222. In calcareous soil, when P was insufficient, i.e., when P was either supplied as KH2PO4 at a concentration of 50 mg P kg-1 soil, or in the form of Phy-P, Ca3-P or Ca10-P, a 43%increase in root length in T149 compared to T222 resulted in an increase in P uptake by 53%, and shoot biomass by 48%. In acid soil, however, when P supply was insufficient, i.e., when P was supplied as KH2PO4 at a concentration of 100 mg P kg-1 soil, or in the form of Phy-P, Fe-P or Al-P, a 32%increase in root length in T149 compared to T222 resulted in an increase in P uptake by only 12%, and shoot biomass by 7%. No significant differences in the exudation of organic acids and APase activity were found between the two genotypes. It is concluded that genetic improvement of root growth can efficiently increase P acquisition in calcareous soils. In acid soils, however, improvements in the physiological traits of roots, in addition to their size, seem to be required for efficient P acquisition.

  14. Improving Chilling Tolerance of Maize Seedlings under Cold Conditions by Spermine Application

    Directory of Open Access Journals (Sweden)

    Amir Hossein SAEIDNEJAD

    2012-08-01

    Full Text Available Low temperature is an important abiotic stress which reduces crops growth and productivity and causes physiological damages to cellular structures. The aim of this study was to investigate the probability of spermine application to improve chilling tolerance of maize under stress conditions. The treatments were included seed priming with spermine (30, 60 and 90 mg/l solutions and normal and stress condition. Seed emergence was improved by spermine priming on both conditions and mean emergence time (MET was also decreased with priming. Shoot and root length was highly reduced under stress conditions, but the treated seeds were improved along with increased spermine concentration. Seedling dry weight was also affected by priming and reduced weight of stressful seedlings was alleviated by spermine priming. Decreased relative water content on seedlings under stress was elevated by the treatments and significantly increased. Electrolyte leakage was also recovered by applied treatments while it was adversely decreased on cold conditions. Antioxidative system was highly responded to spermine application. Superoxide dismutase (SOD activity increased on both normal and stress conditions, but a little decrease was observed on seedlings treated with 90 ppm level and under chilling conditions. Catalase activity was also amplified by spermine treatments. Priming had a great effect on ascorbate peroxidase (APX activity on both stressful and normal seedlings and increased it compare with non treated seedlings. It is also important to note that with increasing spermine concentration to 90 ppm, no considerable differences were observed. Thus, 60 ppm concentration could be proposed as the appropriate level of spermine in order to improve chilling tolerance of maize seedlings.

  15. Seed priming with chitosan improves the germination and growth performance of ajowan

    OpenAIRE

    Batool Mahdavi; Asghar Rahimi

    2013-01-01

    Background: Chitosan is a polysaccharide biopolymer derived from chitin. It not only stimulates growth and increases the crop yields but also alleviates the harmful effect of abiotic stress on plant growth. The objective of this study was to investigate the effects of chitosan on germination and growth of ajowan (Carum copticum) under salt stress. This study was conducted in a laboratory and greenhouse. Material and Methods: In the first experiment seed germination of ajowan monitored und...

  16. Largely improved tensile properties of chitosan film via unique synergistic reinforcing effect of carbon nanotube and clay.

    Science.gov (United States)

    Tang, Changyu; Xiang, Lixue; Su, Juanxia; Wang, Ke; Yang, Changyue; Zhang, Qin; Fu, Qiang

    2008-04-01

    In this work, a great synergistic effect of 2D clay platelets and 1D carbon nanotubes (CNTs) on reinforcing chitosan matrix has been observed for the first time. With incorporation of 3 wt % clay and 0.4 wt % CNTs, the tensile strength and Young's modulus of the nanocomposites are significantly improved by about 171 and 124%, respectively, compared with neat chitosan. This could be understood as due to the formation of much jammed fillers network with 1D CNTs and 2D clay platelets combined together, as indicated by rheological measurement. Our work demonstrates a good example for the preparation of high performance polymer nanocomposites by using nanofillers of different dimension together. PMID:18335921

  17. Cellulose acetate/hydroxyapatite/chitosan coatings for improved corrosion resistance and bioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Zhenyu; Qin, Jinli [Advanced Biomaterials and Tissue Engineering Center, Huazhong University of Science and Technology, Wuhan 430074 (China); Ma, Jun, E-mail: caltary@gmail.com [Advanced Biomaterials and Tissue Engineering Center, Huazhong University of Science and Technology, Wuhan 430074 (China); Department of Biomedical Engineering, School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2015-04-01

    Cellulose acetate (CA) nanofibers were deposited on stainless steel plates by electrospinning technique. The composite of hydroxyapatite (HAP) nanoparticles and chitosan (CHI) was coated subsequently by dip-coating. The structure and morphology of the obtained coatings were investigated by Fourier transform infrared spectroscopy and scanning electron microscopy. The stability of the coatings in physiological environment was studied using electrochemical polarization and impedance spectroscopy. The CA nanofibers were embedded in the HAP/CHI coating and the resulted composite film was densely packed and uniform on the substrate. The in vitro biomineralization study of the coated samples immersed in simulated body fluid (SBF) confirmed the formation ability of bone-like apatite layer on the surface of HAP-containing coatings. Furthermore, the coatings could provide corrosion resistance to the stainless steel substrate in SBF. The electrochemical results suggested that the incorporation of CA nanofibers could improve the corrosion resistance of the HAP/CHI coating. Thus, biocompatible CA/HAP/CHI coated metallic implants could be very useful in the long-term stability of the biomedical applications. - Highlights: • The composite coatings were prepared by electrospinning and dip-coating. • Good in vitro bioactivity of the CA/HAP/CHI coating was confirmed. • Electrochemical behaviors in SBF of the coatings have been studied. • The CA/HAP/CHI coating shows better resistance property than HAP/CHI.

  18. Novel albendazole-chitosan nanoparticles for intestinal absorption enhancement and hepatic targeting improvement in rats.

    Science.gov (United States)

    Liu, Yang; Wang, Xiao-qing; Ren, Wei-xin; Chen, Yuan-lan; Yu, Yang; Zhang, Jian-kang; Bawudong, Dilimulati; Gu, Jun-peng; Xu, Xiao-dong; Zhang, Xue-nong

    2013-08-01

    To improve the treatment of helminthiasis, filariasis, and colorectal cancer, albendazole-associated chitosan nanoparticles (ABZ-CS-NPs) were prepared using the emulsion crosslinking volatile technique with contained sodium tripolyphosphate as the crosslinking agent and Poloxamer 188 as the auxiliary solvent. The structural characteristics of the NPs were determined using X-ray diffraction to analyze the interaction between CS and the drug. The NPs were then evaluated in terms of their physicochemical characteristics, drug release behavior, in vivo pharmacokinetic parameters, and biodistribution in animal studies. ABZ-loaded NPs with a uniformly spherical particle sizes (157.8 ± 2.82 nm) showed efficient drug loading, encapsulated efficiency, and high physical stability. The drug release from ABZ-CS-NPs was extended over several periods. Kinetic models were then fitted to determine the release mechanisms. ABZ and its metabolite albendazole sulfoxide (ABZSX) were analyzed in rats with mebendazole as the internal standard using reversed-phase high-performance liquid chromatography. Compared with the ABZ suspension groups, the relative bioavailability values of ABZ and ABZSX were 146.05 and 222.15%, respectively. In addition, the plasma concentration versus time curve is consistent with that of the two compartment models in the plasma concentration versus time curve. The results indicate that the ABZ-loaded NPs are promising novel ABZ candidates for passive diffusion in the treatment of hydatid cysts in the liver via oral administration. PMID:23529958

  19. Cellulose acetate/hydroxyapatite/chitosan coatings for improved corrosion resistance and bioactivity

    International Nuclear Information System (INIS)

    Cellulose acetate (CA) nanofibers were deposited on stainless steel plates by electrospinning technique. The composite of hydroxyapatite (HAP) nanoparticles and chitosan (CHI) was coated subsequently by dip-coating. The structure and morphology of the obtained coatings were investigated by Fourier transform infrared spectroscopy and scanning electron microscopy. The stability of the coatings in physiological environment was studied using electrochemical polarization and impedance spectroscopy. The CA nanofibers were embedded in the HAP/CHI coating and the resulted composite film was densely packed and uniform on the substrate. The in vitro biomineralization study of the coated samples immersed in simulated body fluid (SBF) confirmed the formation ability of bone-like apatite layer on the surface of HAP-containing coatings. Furthermore, the coatings could provide corrosion resistance to the stainless steel substrate in SBF. The electrochemical results suggested that the incorporation of CA nanofibers could improve the corrosion resistance of the HAP/CHI coating. Thus, biocompatible CA/HAP/CHI coated metallic implants could be very useful in the long-term stability of the biomedical applications. - Highlights: • The composite coatings were prepared by electrospinning and dip-coating. • Good in vitro bioactivity of the CA/HAP/CHI coating was confirmed. • Electrochemical behaviors in SBF of the coatings have been studied. • The CA/HAP/CHI coating shows better resistance property than HAP/CHI

  20. Alfalfa (Medicago sativa L.)/maize (Zea mays L.) intercropping provides a feasible way to improve yield and economic incomes in farming and pastoral areas of northeast China.

    Science.gov (United States)

    Sun, Baoru; Peng, Yi; Yang, Hongyu; Li, Zhijian; Gao, Yingzhi; Wang, Chao; Yan, Yuli; Liu, Yanmei

    2014-01-01

    Given the growing challenges to food and eco-environmental security as well as sustainable development of animal husbandry in the farming and pastoral areas of northeast China, it is crucial to identify advantageous intercropping modes and some constraints limiting its popularization. In order to assess the performance of various intercropping modes of maize and alfalfa, a field experiment was conducted in a completely randomized block design with five treatments: maize monoculture in even rows, maize monoculture in alternating wide and narrow rows, alfalfa monoculture, maize intercropped with one row of alfalfa in wide rows and maize intercropped with two rows of alfalfa in wide rows. Results demonstrate that maize monoculture in alternating wide and narrow rows performed best for light transmission, grain yield and output value, compared to in even rows. When intercropped, maize intercropped with one row of alfalfa in wide rows was identified as the optimal strategy and the largely complementary ecological niches of alfalfa and maize were shown to account for the intercropping advantages, optimizing resource utilization and improving yield and economic incomes. These findings suggest that alfalfa/maize intercropping has obvious advantages over monoculture and is applicable to the farming and pastoral areas of northeast China. PMID:25329376

  1. Improved Biodegradable Radiation Cured Polymeric Film Prepared from Chitosan-Gelatin Blend

    Directory of Open Access Journals (Sweden)

    Zinia Nasreen

    2016-01-01

    Full Text Available The mechanical, thermal, swelling, and release properties of chitosan-gelatin (CG films have been investigated in order to verify the influence of UV and gamma radiation on the stability of the films. Thin films of chitosan and gelatin (1 : 3, w/w that were radiated with 100 krad of gamma dose showed the best performance and the TS values reached 25, 45, and 49 MPa, respectively, for chitosan, gelatin, and blend. The corresponding highest TS values were 23, 42, and 45 MPa, respectively, for 10 passes of UV radiation. The effect of radiation over gelatin, chitosan, and CG blend caused modification in the arrangement of molecules in the crystal lattice that is significant by XRD analysis. Surfaces of the films were also investigated by scanning electron microscope (SEM. Fourier transform infrared spectroscopy (FTIR studies further revealed structural changes of the films. These changes were attributed to understanding the behavior of the irradiated chitosan, gelatin, and CG blend on application of thermal energy using DSC and TGA studies, water uptake of the films in aqueous medium, and soil degradation properties to observe the best possibility for its application.

  2. Much Improved Irrigation Use Efficiency in an Intensive Wheat-Maize Double Cropping System in the North China Plain

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Crop yield and water use efficiency (WUE) in a wheat-maize double cropping system are influenced by short and uneven rainfalls in the North China Plain (NCP). A 2-year experiment was conducted to investigate the effects of irrigation on soil water balance, crop yield and WUE to improve irrigation use efficiency in the cropping system. Soil water depletion (△SWS)by crop generally decreased with the increase of irrigation and rainfall, while △SWS for the whole rotation was relatively stable among these irrigation treatments. High irrigations in wheat season increased initial soil moisture and △SWS for subsequent maize especially in the drought season. Initial soil water influenced mainly by the irrigation and rainfall in the previous crop season, is essential to high yield in such cropping systems. Grain yield decreased prior to evapotranspiration(ET) when ET reached about 300 mm for wheat, while maize showed various WUEs with similar seasonal ET. For whole rotation, WUE declined when ET exceeded about 650 mm. These results indicate great potential for improving irrigation use efficiency in such wheat-maize cropping system in the NCP. Based on the present results, reasonable irrigation schedules according to different annual rainfall conditions are presented for such a cropping system.

  3. Nitrogen Deifciency Limited the Improvement of Photosynthesis in Maize by Elevated CO2 Under Drought

    Institute of Scientific and Technical Information of China (English)

    ZONG Yu-zheng; SHANGGUAN Zhou-ping

    2014-01-01

    Global environmental change affects plant physiological and ecosystem processes. The interaction of elevated CO2, drought and nitrogen (N) deficiency result in complex responses of C4 species photosynthetic process that challenge our current understanding. An experiment of maize (Zea mays L.) involving CO2 concentrations (380 or 750 µmol mol-1, climate chamber), osmotic stresses (10% PEG-6000, -0.32 MPa) and nitrogen constraints (N deficiency treated since the 144th drought hour) was carried out to investigate its photosynthesis capacity and leaf nitrogen use efficiency. Elevated CO2 could alleviate drought-induced photosynthetic limitation through increasing capacity of PEPC carboxylation (Vpmax) and decreasing stomatal limitations (SL). The N deifciency exacerbated drought-induced photosynthesis limitations in ambient CO2. Elevated CO2 partially alleviated the limitation induced by drought and N deifciency through improving the capacity of Rubisco carboxylation (Vmax) and decreasing SL. Plants with N deifciency transported more N to their leaves at elevated CO2, leading to a high photosynthetic nitrogen-use efifciency but low whole-plant nitrogen-use efifciency. The stress mitigation by elevated CO2 under N deifciency conditions was not enough to improving plant N use efifciency and biomass accumulation. The study demonstrated that elevated CO2 could alleviate drought-induced photosynthesis limitation, but the alleviation varied with N supplies.

  4. Production and characterization of chitosan/gelatin/β-TCP scaffolds for improved bone tissue regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Serra, I.R.; Fradique, R.; Vallejo, M.C.S.; Correia, T.R.; Miguel, S.P.; Correia, I.J., E-mail: icorreia@ubi.pt

    2015-10-01

    Recently, bone tissue engineering emerged as a viable therapeutic alternative, comprising bone implants and new personalized scaffolds to be used in bone replacement and regeneration. In this study, biocompatible scaffolds were produced by freeze-drying, using different formulations (chitosan, chitosan/gelatin, chitosan/β-TCP and chitosan/gelatin/β-TCP) to be used as temporary templates during bone tissue regeneration. Sample characterization was performed through attenuated total reflectance-Fourier transform infrared spectroscopy, X-ray diffraction and energy dispersive spectroscopy analysis. Mechanical characterization and porosity analysis were performed through uniaxial compression test and liquid displacement method, respectively. In vitro studies were also done to evaluate the biomineralization activity and the cytotoxic profile of the scaffolds. Scanning electron and confocal microscopy analysis were used to study cell adhesion and proliferation at the scaffold surface and within their structure. Moreover, the antibacterial activity of the scaffolds was also evaluated through the agar diffusion method. Overall, the results obtained revealed that the produced scaffolds are bioactive and biocompatible, allow cell internalization and show antimicrobial activity against Staphylococcus aureus. Such, make these 3D structures as potential candidates for being used on the bone tissue regeneration, since they promote cell adhesion and proliferation and also prevent biofilm development at their surfaces, which is usually the main cause of implant failure. - Highlights: • Production of 3D scaffolds composed by chitosan/gelatin/β-TCP by freeze-drying for bone regeneration • Physicochemical characterization of the bone substitutes by SEM, FTIR, XRD and EDS • Evaluation of the cytotoxic profile and antibacterial activity of the 3D structures through in vitro assays.

  5. Production and characterization of chitosan/gelatin/β-TCP scaffolds for improved bone tissue regeneration

    International Nuclear Information System (INIS)

    Recently, bone tissue engineering emerged as a viable therapeutic alternative, comprising bone implants and new personalized scaffolds to be used in bone replacement and regeneration. In this study, biocompatible scaffolds were produced by freeze-drying, using different formulations (chitosan, chitosan/gelatin, chitosan/β-TCP and chitosan/gelatin/β-TCP) to be used as temporary templates during bone tissue regeneration. Sample characterization was performed through attenuated total reflectance-Fourier transform infrared spectroscopy, X-ray diffraction and energy dispersive spectroscopy analysis. Mechanical characterization and porosity analysis were performed through uniaxial compression test and liquid displacement method, respectively. In vitro studies were also done to evaluate the biomineralization activity and the cytotoxic profile of the scaffolds. Scanning electron and confocal microscopy analysis were used to study cell adhesion and proliferation at the scaffold surface and within their structure. Moreover, the antibacterial activity of the scaffolds was also evaluated through the agar diffusion method. Overall, the results obtained revealed that the produced scaffolds are bioactive and biocompatible, allow cell internalization and show antimicrobial activity against Staphylococcus aureus. Such, make these 3D structures as potential candidates for being used on the bone tissue regeneration, since they promote cell adhesion and proliferation and also prevent biofilm development at their surfaces, which is usually the main cause of implant failure. - Highlights: • Production of 3D scaffolds composed by chitosan/gelatin/β-TCP by freeze-drying for bone regeneration • Physicochemical characterization of the bone substitutes by SEM, FTIR, XRD and EDS • Evaluation of the cytotoxic profile and antibacterial activity of the 3D structures through in vitro assays

  6. Comparative effectiveness of different Rhizobium sp. for improving growth and yield of maize (Zea mays L.

    Directory of Open Access Journals (Sweden)

    Ijaz Mehboob, Zahir Ahmad Zahir, Muhammad Arshad, Muhammad Khalid

    2012-05-01

    Full Text Available During the last couple of decades, it has been demonstrated that rhizobia can associate with roots of non-legumes also without forming true nodules, and can promote their growth by using one or more of the direct or indirect mechanisms of actions. This work examines the growth and yield responses of maize to inoculation with different species of rhizobia, isolated from the root nodules of chickpea (Cicer arietinum L., lentil (Lens culinaris M. and mung bean (Vigna radiata L. in pots and fields. Twenty isolates of rhizobia were isolated from root nodules each of mung bean, lentil and chickpea and were screened under axenic conditions. On the basis of their promising performance under axenic conditions, nine most efficient isolates (three from each legume host were selected, characterized and further evaluated for their growth promoting activities by conducting pot and field experiments. Results of pot experiment revealed that maximum increase in grain yield, 1000 grain weight, N, P and K uptake (up to 47.89, 54.52, 73.46, 84.66 and 59.19% by CRI28, respectively, over un-inoculated control was produced by the isolate of Mesorhizobium ciceri. Whereas, maximum improvement in rest of the parameters was caused by the isolates of Rhizobium phaseoli (i.e. fresh biomass, straw yield and root length up to 36.30% by A18, 25.46% by S6 and 81.89% by A18, respectively over un-inoculated control. Rhizobium leguminosarum isolates came out to be the least effective among the species tested. Similarly, all the selected isolates improved the growth and yield attributing parameters in fields as well but with varying capacity compared with un-inoculated control. The selected isolates of Mesorhizobium ciceri and Rhizobium phaseoli again remained superior compared to the isolates of Rhizobium leguminosarum under field conditions. The results of this study imply that rhizobium species had potential to promote growth and yield of maize but this technology should be

  7. Improving agricultural productivity in the savannah of Tabasco State, Mexico: I. Management of maize and sorghum production systems

    International Nuclear Information System (INIS)

    A series of studies was carried out to evaluate the effects of selected biological components of agrosystems, in particular mycorrhizae, earthworms, and Trichoderma on sorghum and maize crop production in an acid Ultisol of the savannah of Huimanguillo, Tabasco state, Mexico. Isotopic techniques using 15N and 32P were used to assess N and P use efficiency of sorghum transgenic lines (citrate over-producers) under nutrient-limited conditions. No significant differences in 15N-fertilizer use efficiency between the lines tested (L8, a citrate over-producer) and a commercial genotype were found. The commercial line and a negative control (L18-2 transgenic line), showed the highest N derived from the fertilizer as well as P uptake derived from rock phosphate. The combined application of the legume green-manure Mucuna pruriens and earthworms (Balanteodrilus pearsei) had a positive effect on N and P uptake and maize yields (78 g grain plant-1 vs. 26 g grain plant-1 for the control). Inoculation of maize with Trichoderma enhanced the effect of N fertilization and the N-uptake efficiency was highest when the fertilizer N was applied at sowing. Both Trichoderma strain C4 and the commercial inoculant 'Tricom' gave the highest values of N-fertilizer use efficiency (43 and 38%, respectively), which was equivalent to a 2.4-fold increase over that found when fertilizer was applied alone. In a field evaluation of maize genotypes, the genotype VS-536 yielded 2.35 Mg grain ha-1 and highest fertilizer N efficiency when 100 kg P2O5 ha-1 of the reactive Baja California PR was applied, suggesting that this genotype could be used in the local production system. Interestingly, inoculation with mycorrhizae did not have positive effects on the fertilized maize. Overall, these data will contribute to establish better management practices for increasing soil fertility and improving crop production in the acid, unfertile savannah soils of Mexico. (author)

  8. Chitosan-based dressings loaded with neurotensin—an efficient strategy to improve early diabetic wound healing

    OpenAIRE

    Moura, Liane I. F.; Dias, Ana M. A.; Ermelindo C. Leal; Carvalho, Lina; Sousa, Hermínio C. de; Carvalho, Eugénia

    2014-01-01

    One important complication of diabetes mellitus is chronic, non-healing diabetic foot ulcers (DFUs). This study aims to develop and use dressings based on chitosan derivatives for the sustained delivery of neurotensin (NT), a neuropeptide that acts as an inflammatory modulator in wound healing. Three different derivatives, namely N-carboxymethyl chitosan, 5-methyl pyrrolidinone chitosan (MPC) and N-succinyl chitosan, are presented as potential biomaterials for wound healing applications. Our ...

  9. Tight junction modulation by chitosan nanoparticles: comparison with chitosan solution.

    Science.gov (United States)

    Vllasaliu, Driton; Exposito-Harris, Ruth; Heras, Angeles; Casettari, Luca; Garnett, Martin; Illum, Lisbeth; Stolnik, Snow

    2010-11-15

    Present work investigates the potential of chitosan nanoparticles, formulated by the ionic gelation with tripolyphosphate (TPP), to open the cellular tight junctions and in doing so, improve the permeability of model macromolecules. A comparison is made with chitosan solution at equivalent concentrations. Initial work assessed cytotoxicity (through MTS and LDH assays) of chitosan nanoparticles and solutions on Calu-3 cells. Subsequently, a concentration of chitosan nanoparticles and solution exhibiting minimal toxicity was used to investigate the effect on TEER and macromolecular permeability across filter-cultured Calu-3 monolayer. Chitosan nanoparticles and solution were also tested for their effect on the distribution of the tight junction protein, zonnula occludens-1 (ZO-1). Chitosan nanoparticles produced a sharp and reversible decrease in TEER and increased the permeability of two FITC-dextrans (FDs), FD4 (MW 4 kDa) and FD10 (MW 10 kDa), with effects of a similar magnitude to chitosan solution. Chitosan nanoparticles produced changes in ZO-1 distribution similar to chitosan solution, indicating a tight junction effect. While there was no improvement in permeability with chitosan nanoparticles compared to solution, nanoparticles provide the potential for drug incorporation, and hence the possibility for providing controlled drug release and protection from enzymatic degradation. PMID:20727955

  10. Nutritional and safety assessments of foods and feeds nutritionally improved through biotechnology: lysine maize as a case study.

    Science.gov (United States)

    Glenn, Kevin C

    2007-01-01

    During the last decade, the area of biotech crops modified for agronomic input traits (e.g., herbicide tolerance and insect protection) has increased to 90 million halyear, grown by over 8 million farmers in a total of 17 countries. As adoption of these improved agronomic trait biotech crops has grown, so has interest in biotech crops that have improved nutritional characteristics for use as feed and food. A previous publication by the International Life Sciences Institute (ILSI) reported on the principles and concepts proposed for the nutritional and safety assessments of foods and feeds nutritionally improved through biotechnology. In this paper, the guidelines and principles recommended in the earlier publication are discussed relative to a specific case study, Lysine maize. Lysine maize is a feed ingredient with enhanced nutritional characteristics for poultry and swine and provides an alternative to the need for addition of supplemental lysine to some diets for these animals. The 2004 Task Force of the ILSI has also applied the concepts from that report to 4 other case studies: sweet potato enriched in provitamin A (2 examples, one using biotechnology and one using conventional breeding); Golden Rice 2; double-embryo maize; and ASP-1 enhanced protein sweet potato. PMID:17955996

  11. Utilization of maize cob biochar and rice husk charcoal as soil amendments for improving acid soil fertility and productivity

    Directory of Open Access Journals (Sweden)

    Nurhidayati

    2014-10-01

    Full Text Available The decline in soil fertility in agricultural land is a major problem that causes a decrease in the production of food crops. One of the causes of the decline in soil fertility is declining soil pH that caused the decline in the availability of nutrients in the soil. This study aimed to assess the influence of alternative liming materials derived from maize cob biochar and rice husk charcoal compared to conventional lime to improve soil pH, soil nutrient availability and maize production. The experiment used a factorial complete randomized design which consisting of two factors. The first factor is the type of soil amendment which consists of three levels (calcite lime, rice husk charcoal and cob maize biochar. The second factor is the application rates of the soil amendment consisted of three levels (3, 6 and 9 t/ha and one control treatment (without soil amendment. The results of this study showed that the application of various soil amendment increased soil pH, which the pH increase of the lime application was relatively more stable over time compared to biochar and husk charcoal. The average of the soil pH increased for each soil amendment by 23% (lime, 20% (rice husk charcoal and 23% (biochar as compared with control. The increase in soil pH can increase the availability of soil N, P and K. The greatest influence of soil pH on nutrient availability was shown by the relationship between soil pH and K nutrient availability with R2 = 0.712, while for the N by R2 = 0.462 and for the P by R2 = 0.245. The relationship between the availability of N and maize yield showed a linear equation. While the relationship between the availability of P and K with the maize yield showed a quadratic equation. The highest maize yield was found in the application of biochar and rice husk charcoal with a dose of 6-9 t/ha. The results of this study suggested that biochar and husk charcoal could be used as an alternative liming material in improving acid soil

  12. Nanoamphiphilic Chitosan Dispersed Poly(lactic acid) Bionanocomposite Films with Improved Thermal, Mechanical, and Gas Barrier Properties.

    Science.gov (United States)

    Pal, Akhilesh Kumar; Katiyar, Vimal

    2016-08-01

    This article demonstrates the synthesis of lactic acid oligomer-grafted-chitosan (OLLA-g-CH), a nanoamphiphilic molecule, by in situ condensation polymerization and its effective use as a nanofiller for improvement in multiple properties of poly(lactic acid) (PLA) films, essential for stringent food packaging applications. Fourier transform infrared spectroscopy (FTIR) analysis shows the presence of amide-ester bond at 1539 cm(-1), which confirms the structural grafting of OLLA chains with chitosan molecules. This nanoamphiphilic OLLA-g-CH molecule act as surfactant containing hydrophilic chitosan head and hydrophobic OLLA tails with average size in the range of ∼2-4 nm. Prepared PLA/OLLA-g-CH bionanocomposite films appear with uniform dispersion of nanoamphiphilic OLLA-g-CH molecules with self-assembled micelles having size as low as ∼20 nm and as high as ∼150 nm with core-shell morphology in PLA matrix. This nanofiller is found very effective toward significant reduction in oxygen permeability (OP) by ∼10-fold due to the reduction in solubility of oxygen molecules and improvement in crystal nucleation density due to availability of nanonucleating sites. Ultimate tensile strength (UTS) of PLA/OLLA-g-CH bionanocomposite films are relatively comparable to that of PLA, however, elongation at break is improved significantly. The onset of thermal degradation of PLA/(OLLA-g-CH) films is also found comparable to that of PLA film. The glass transition temperature (Tg) of bionanocomposites is decreased by more than 18 °C with increase in OLLA-g-CH loading, which indicates the improved plasticization characteristics of PLA matrix. The crystallization kinetics suggest nonthree dimensional truncated spherical structures, which is controlled by the combination of thermal and athermal instantaneous nucleations. POM analysis suggested that the spherulite growth of PLA is improved significantly with the addition of OLLA-g-CH. The reduction in Tg of PLA with improvement

  13. Halofuginone- and Chitosan-Coated Amnion Membranes Demonstrate Improved Abdominal Adhesion Prevention

    Directory of Open Access Journals (Sweden)

    Scott Washburn

    2010-01-01

    Full Text Available Our objective was to determine whether coating the amniotic membrane with halofuginone, a type 1 collagen synthase inhibitor, with or without the hemostasis-inducing substance chitosan, reduced the number and severity of adhesions in the rat uterine horn injury model. Sixty retired breeder Sprague-Dawley rats underwent midline laparotomy and a zone of ischemia was created in the left uterine horn of each animal. Rats were randomized to one of six treatment groups: (1 untreated control, (2 oxidized regenerated cellulose (Interceed® (ORC, (3 plain amnion, (4 amnion coated on both sides with 0.5% solution of halofuginone (HAH, (5 amnion coated on one side with 0.5% halofuginone and on the other side with chitosan (CAH, or (6 amnion coated on both sides with chitosan (CAC. The zone of ischemia in each left uterine horn was wrapped in each treatment. Rats were sacrificed 2 weeks after laparotomy, and adhesions were counted and scored for severity. Data were analyzed using Chi square and a p <0.05 was considered significant. Our results showed that there were no differences in the percentage of animals with adhesions in the untreated, ORC, plain amnion, or CAC groups. No adhesions formed in any animal in the HAH group and only 14% of the animals developed adhesions to the uterine horn in the CAH group (p < 0.05. The percentage of animals with moderate and severe adhesions did not differ between untreated controls and the ORC groups, but were significantly reduced in all four of the amnion groups: plain amnion, HAH, CAH, and CAC (p < 0.05. Amnion coated with halofuginone alone or in combination with chitosan reduced the percentage of animals with adhesions, as well as the percentage of animals with moderate and severe adhesions compared to untreated controls and the ORC group in the rat uterine horn injury model. Amnion alone or coated with chitosan reduced the percentage of rats with moderate and severe adhesions, but not the percentage of rats with

  14. Identification and genetic characterization of maize cell wall variation for improved biorefinery feedstock characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Pauly, Markus [UC Berkeley; Hake, Sarah [USDA Albany

    2013-10-31

    The objectives of this program are to 1) characterize novel maize mutants with altered cell walls for enhanced biorefinery characteristics and 2) find quantitative trait loci (QTLs) related to biorefinery characteristics by taking advantage of the genetic diversity of maize. As a result a novel non-transgenic maize plant (cal1) has been identified, whose stover (leaves and stalk) contain more glucan in their walls leading to a higher saccharification yield, when subjected to a standard enzymatic digestion cocktail. Stacking this trait with altered lignin mutants yielded evene higher saccharification yields. Cal-1 mutants do not show a loss of kernel and or biomass yield when grown in the field . Hence, cal1 biomass provides an excellent feedstock for the biofuel industry.

  15. A maize phytochrome-interacting factor 3 improves drought and salt stress tolerance in rice.

    Science.gov (United States)

    Gao, Yong; Jiang, Wei; Dai, Yi; Xiao, Ning; Zhang, Changquan; Li, Hua; Lu, Yi; Wu, Meiqin; Tao, Xiaoyi; Deng, Dexiang; Chen, Jianmin

    2015-03-01

    Phytochrome-interacting factor 3 (PIF3) activates light-responsive transcriptional network genes in coordination with the circadian clock and plant hormones to modulate plant growth and development. However, little is known of the roles PIF3 plays in the responses to abiotic stresses. In this study, the cloning and functional characterization of the ZmPIF3 gene encoding a maize PIF3 protein is reported. Subcellular localization revealed the presence of ZmPIF3 in the cell nucleus. Expression patterns revealed that ZmPIF3 is expressed strongly in leaves. This expression responds to polyethylene glycol, NaCl stress, and abscisic acid application, but not to cold stress. ZmPIF3 under the control of the ubiquitin promoter was introduced into rice. No difference in growth and development between ZmPIF3 transgenic and wild-type plants was observed under normal growth conditions. However, ZmPIF3 transgenic plants were more tolerant to dehydration and salt stresses. ZmPIF3 transgenic plants had increased relative water content, chlorophyll content, and chlorophyll fluorescence, as well as significantly enhanced cell membrane stability under stress conditions. The over-expression of ZmPIF3 increased the expression of stress-responsive genes, such as Rab16D, DREB2A, OSE2, PP2C, Rab21, BZ8 and P5CS, as detected by real-time PCR analysis. Taken together, these results improve our understanding of the role ZmPIF3 plays in abiotic stresses signaling pathways; our findings also indicate that ZmPIF3 regulates the plant response to drought and salt stresses. PMID:25636202

  16. Superparamagnetic iron oxide/chitosan core/shells for hyperthermia application: Improved colloidal stability and biocompatibility

    Energy Technology Data Exchange (ETDEWEB)

    Patil, R.M.; Shete, P.B.; Thorat, N.D.; Otari, S.V. [Center for Interdisciplinary Research, D.Y. Patil University, Kolhapur 416006, MS (India); Barick, K.C.; Prasad, A.; Ningthoujam, R.S. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, MS (India); Tiwale, B.M. [Center for Interdisciplinary Research, D.Y. Patil University, Kolhapur 416006, MS (India); Pawar, S.H., E-mail: pawar_s_h@yahoo.com [Center for Interdisciplinary Research, D.Y. Patil University, Kolhapur 416006, MS (India)

    2014-04-15

    Superparamagnetic magnetite nanoparticles are of great interest due to their potential biomedical applications. In the present investigation, Fe{sub 3}O{sub 4} magnetic nanoparticles were prepared by alkaline precipitation using ferrous chloride as the sole source. An amphiphilic polyelectrolyte with the property of biocompatibility and functional carboxyl groups was used as a stabilizer to prepare a well-dispersed suspension of superparamagnetic Fe{sub 3}O{sub 4} nanoparticles. The final material composed of Fe{sub 3}O{sub 4} core and chitosan (CH) shell was produced. The amino groups of CH coated on Fe{sub 3}O{sub 4} nanoparticles were further cross linked using glutaraldehyde (GLD) for stable coating. FTIR spectra, XPS and TGA confirmed the coating of CH/GLD on the surface of Fe{sub 3}O{sub 4} nanoparticles. XRD patterns indicate the pure phase Fe{sub 3}O{sub 4} with a spinel structure. The nanoparticles were superparamagnetic at room temperature with saturation magnetization values for bare and coated nanoparticles which were 51.68 emu/g and 48.60 emu/g, respectively. Zeta potential values showed higher colloidal stability of coated nanoparticles than the bare one. Cytotoxicity study up to 2 mg mL{sup −1} concentration showed no drastic change in cell viability of nanoparticles after coating. Also, coated nanoparticles showed increased SAR value, making them suitable for hyperthermia therapy application. - Highlights: • Fe{sub 3}O{sub 4} nanoparticles were synthesized from FeCl{sub 2} as the sole source by alkaline precipitation. • Coating of Fe{sub 3}O{sub 4} nanoparticles was done with chitosan by simple ultrasonication. • Chitosan cross-linked with glutaraldehyde. • High colloidal stability was observed. • Increased SAR value and least cytotoxicity were observed.

  17. Superparamagnetic iron oxide/chitosan core/shells for hyperthermia application: Improved colloidal stability and biocompatibility

    International Nuclear Information System (INIS)

    Superparamagnetic magnetite nanoparticles are of great interest due to their potential biomedical applications. In the present investigation, Fe3O4 magnetic nanoparticles were prepared by alkaline precipitation using ferrous chloride as the sole source. An amphiphilic polyelectrolyte with the property of biocompatibility and functional carboxyl groups was used as a stabilizer to prepare a well-dispersed suspension of superparamagnetic Fe3O4 nanoparticles. The final material composed of Fe3O4 core and chitosan (CH) shell was produced. The amino groups of CH coated on Fe3O4 nanoparticles were further cross linked using glutaraldehyde (GLD) for stable coating. FTIR spectra, XPS and TGA confirmed the coating of CH/GLD on the surface of Fe3O4 nanoparticles. XRD patterns indicate the pure phase Fe3O4 with a spinel structure. The nanoparticles were superparamagnetic at room temperature with saturation magnetization values for bare and coated nanoparticles which were 51.68 emu/g and 48.60 emu/g, respectively. Zeta potential values showed higher colloidal stability of coated nanoparticles than the bare one. Cytotoxicity study up to 2 mg mL−1 concentration showed no drastic change in cell viability of nanoparticles after coating. Also, coated nanoparticles showed increased SAR value, making them suitable for hyperthermia therapy application. - Highlights: • Fe3O4 nanoparticles were synthesized from FeCl2 as the sole source by alkaline precipitation. • Coating of Fe3O4 nanoparticles was done with chitosan by simple ultrasonication. • Chitosan cross-linked with glutaraldehyde. • High colloidal stability was observed. • Increased SAR value and least cytotoxicity were observed

  18. Enhancing Biological Wastewater Treatment with Chitosan

    Institute of Scientific and Technical Information of China (English)

    陈亮; 陈东辉; 朱珺

    2003-01-01

    Chitin and chitosan have been applied to biological wastewater treatment.From a number of parallel comparison experiments,it can be concluded that the application of chitin and chitosan can both enhance the biological treatment,besides which chitosan is more efficient than chitin.The study on the enhancement mechanism reveals the difference between the two additives:chitosan improves the sludge structure and settlibility,while chitin acts as a kind of carrier for microorganism in the biological treatment system.

  19. Length of Selection Around Candidate Genes for Artificial Selection During Domestication and Crop Improvement in Maize

    Science.gov (United States)

    Genomic screens for artificial selection have been successful in identifying candidate genes for agronomic traits in maize (Zea mays L). However, the validity of the candidates identified requires that selection sweeps are very short, only containing the candidate gene with the nearest neighboring g...

  20. Improving weed management and crop productivity in maize systems in Zimbabwe

    NARCIS (Netherlands)

    Mashingaidze, A.B.

    2004-01-01

    Keywords: Intercropping, narrow planting, precise fertilizer placement, radiation interception, leaf stripping, detasselling, Land Equivalent Ratio, maize, pumpkin, dry beans, reduced herbicide dosagesIn the tropics, weeds cause more

  1. Improved Evapotranspiration Simulation In the CERES-Maize Crop Model Under Limited Irrigation Management

    Science.gov (United States)

    An increasingly considered alternative to full irrigation practices is limited irrigation, where the crop is intentionally stressed during specific growth stages in an effort to maximize yield per unit water consumed, or evapotranspiration (ET). Recent studies have shown that CERES-Maize crop model...

  2. Towards improved nitrogen management in silage maize production on sandy soils.

    NARCIS (Netherlands)

    Schroder, J.J.

    1998-01-01

    Maize has become a highly appreciated crop in Dutch dairy farming during the last 25 years. The current cropping technique, however, is associated with a low recovery of soil mineral nitrogen (N) and serious losses of N to the environment. This gave rise to the research described in this thesis whic

  3. Flavone-rich maize: An opportunity to improve the nutritional value of an important commodity crop

    Directory of Open Access Journals (Sweden)

    Maria Isabel Casas

    2014-09-01

    Full Text Available Agricultural outputs have resulted in food production continuously expanding. Satisfying the needs of a fast growing human population, higher yields, more efficient food processing, and food esthetic value, resulted in crop varieties with higher caloric intake but lacking many phytochemicals important for plant protection and adequate human nutrition. The increasing incidence of chronic diseases such as obesity, diabetes and cardiovascular diseases, combined with social disparity worldwide prompted the interest in developing enhanced crops that can simultaneously address the two sides of the current malnutrition sword, increasing yield while providing added nutritional value. Flavones, phytochemicals associated with the beneficial effects of the Mediterranean diet, have potent anti-inflammatory and anti-carcinogenic activities. However, many Mediterranean diet-associated vegetables are inaccessible, or lowly consumed, in many parts of the world. Maize is the most widely grown cereal crop, yet most lines used for hybrid maize production lack flavones. As a first step towards a sustainable strategy to increasing the nutritional value of maize-based diets, we investigated the accumulation and chemical properties of flavones in maize seeds of defined genotypes. We show that the pericarps of the P1-rr genotype accumulate flavones at levels comparable to those present in some flavone-rich vegetables, and are mostly present in their C- and O-glycosylated forms. Some of these glycosides can be readily converted into the corresponding more active health beneficial aglycones during food processing. Our results provide evidence that nutritionally beneficial flavones could be re-introduced into elite lines to increase the dietary benefits of maize.

  4. Flavone-rich maize: an opportunity to improve the nutritional value of an important commodity crop.

    Science.gov (United States)

    Casas, María I; Duarte, Silvia; Doseff, Andrea I; Grotewold, Erich

    2014-01-01

    Agricultural outputs have resulted in food production continuously expanding. To satisfy the needs of a fast growing human population, higher yields, more efficient food processing, and food esthetic value, new crop varieties with higher caloric intake have and continue to be developed, but which lack many phytochemicals important for plant protection and adequate human nutrition. The increasing incidence of chronic diseases such as obesity, diabetes and cardiovascular diseases, combined with social disparity worldwide prompted the interest in developing enhanced crops that can simultaneously address the two sides of the current malnutrition sword, increasing yield while providing added nutritional value. Flavones, phytochemicals associated with the beneficial effects of the Mediterranean diet, have potent anti-inflammatory and anti-carcinogenic activities. However, many Mediterranean diet-associated vegetables are inaccessible, or lowly consumed, in many parts of the world. Maize is the most widely grown cereal crop, yet most lines used for hybrid maize production lack flavones. As a first step toward a sustainable strategy to increasing the nutritional value of maize-based diets, we investigated the accumulation and chemical properties of flavones in maize seeds of defined genotypes. We show that the pericarps of the P1-rr genotype accumulate flavones at levels comparable to those present in some flavone-rich vegetables, and are mostly present in their C- and O-glycosylated forms. Some of these glycosides can be readily converted into the corresponding more active health beneficial aglycones during food processing. Our results provide evidence that nutritionally beneficial flavones could be re-introduced into elite lines to increase the dietary benefits of maize. PMID:25250036

  5. Evaluation of Chitosan-Starch-Based Edible Coating To Improve the Shelf Life of Bod Ljong Cheese.

    Science.gov (United States)

    Mei, Jun; Guo, Qizhen; Wu, Yan; Li, Yunfei

    2015-07-01

    The objective of this work was to evaluate the effectiveness of antimicrobial edible coatings to improve the quality of Bod ljong cheese throughout 25 days of storage. Coatings were prepared using chitosan, water chestnut starch, and glycerol as a base matrix, together with several combinations of antimicrobial substances: Cornus officinalis fruit extract (COFE), pine needle essential oil (PNEO), and nisin. Application of coating on cheese decreased water loss, lipid oxidation, changes in headspace gas composition, and color. Moreover, the edible coatings with COFE or PNEO had increased antimicrobial activity and did not permit growth of microorganisms. COFE and PNEO are manufactured from food-grade materials so they can be consumed as an integral part of the cheese, which represents a competitive advantage over nonedible coatings. PMID:26197284

  6. Characterization of Chitosan Nanofiber Sheets for Antifungal Application

    Directory of Open Access Journals (Sweden)

    Mayumi Egusa

    2015-11-01

    Full Text Available Chitosan produced by the deacetylation of chitin is a cationic polymer with antimicrobial properties. In this study, we demonstrate the improvement of chitosan properties by nanofibrillation. Nanofiber sheets were prepared from nanofibrillated chitosan under neutral conditions. The Young’s modulus and tensile strength of the chitosan NF sheets were higher than those of the chitosan sheets prepared from dissolving chitosan in acetic acid. The chitosan NF sheets showed strong mycelial growth inhibition against dermatophytes Microsporum and Trichophyton. Moreover, the chitosan NF sheets exhibited resistance to degradation by the fungi, suggesting potentials long-lasting usage. In addition, surface-deacetylated chitin nanofiber (SDCNF sheets were prepared. The SDCNF sheet had a high Young’s modulus and tensile strength and showed antifungal activity to dermatophytes. These data indicate that nanofibrillation improved the properties of chitosan. Thus, chitosan NF and SDCNF sheets are useful candidates for antimicrobial materials.

  7. Development by extrusion of soyabari snack sticks: a nutritionally improved soya-maize product based on the Nigerian snack (kokoro).

    Science.gov (United States)

    Omueti, O; Morton, I D

    1996-01-01

    A nutritionally improved local snack compared to existing kokoro has been developed by extrusion cooking of different formulations of maize, soybean and condiments such as pepper, onion, salt, palm oil, plantain and banana. The improved snack was named as the 'soyabari snack stick'. The chemical composition of representative extruded products indicates a high level of crude protein, fat, energy, available lysine and improved in vitro digestibility compared to the usual maize-based products. The level of stachyose and raffinose were greatly reduced in the extruded products compared to raw soya. Formulations using various additives yielded products suitable for different consumers' preferences such as hot, sweet, bland, gritty or crispy and acceptable to taste assessors. Soyabari snack sticks were equally acceptable as Bombay mix, a product on the market in London. Sensory analysis showed no significant differences in the two products but the crude fibre content of Bombay mix was higher while the protein was slightly lower than for soyabari sticks. Local ingredients can produce acceptable extrudates. PMID:8616673

  8. Improving aerobic stability and biogas production of maize silage using silage additives.

    Science.gov (United States)

    Herrmann, Christiane; Idler, Christine; Heiermann, Monika

    2015-12-01

    The effects of air stress during storage, exposure to air at feed-out, and treatment with silage additives to enhance aerobic stability on methane production from maize silage were investigated at laboratory scale. Up to 17% of the methane potential of maize without additive was lost during seven days exposure to air on feed-out. Air stress during storage reduced aerobic stability and further increased methane losses. A chemical additive containing salts of benzoate and propionate, and inoculants containing heterofermentative lactic acid bacteria were effective to increase aerobic stability and resulted in up to 29% higher methane yields after exposure to air. Exclusion of air to the best possible extent and high aerobic stabilities should be primary objectives when ensiling biogas feedstocks. PMID:26348286

  9. Strategies to improve low copy transgenic events in Agrobacterium-mediated transformation of maize.

    Science.gov (United States)

    Sivamani, Elumalai; Li, Xianggan; Nalapalli, Samson; Barron, Yoshimi; Prairie, Anna; Bradley, David; Doyle, Michele; Que, Qiudeng

    2015-12-01

    Transgenic plants containing low copy transgene insertion free of vector backbone are highly desired for many biotechnological applications. We have investigated two different strategies for increasing the percentage of low copy events in Agrobacterium-mediated transformation experiments in maize. One of the strategies is to use a binary vector with two separate T-DNAs, one T-DNA containing an intact E.coli manA gene encoding phosphomannose isomerase (PMI) as selectable marker gene cassette and another T-DNA containing an RNAi cassette of PMI sequences. By using this strategy, low copy transgenic events containing the transgenes were increased from 43 to 60 % in maize. An alternate strategy is using selectable marker gene cassettes containing regulatory or coding sequences derived from essential plant genes such as 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) or MADS box transcription factor. In this paper we demonstrate that higher percentage of low copy transgenic events can be obtained in Agrobacterium-mediated maize transformation experiments using both strategies. We propose that the above two strategies can be used independently or in combination to increase transgenic events that contain low copy transgene insertion in Agrobacterium-mediated transformation experiments. PMID:26338266

  10. Six month-duration Tephrosia vogelii Hook. f. and Tithonia diversifolia (Hemsl. A. Gray planted-fallows for improving maize production in Kenya

    Directory of Open Access Journals (Sweden)

    Gachene C.K.K.

    2008-01-01

    Full Text Available An experiment including planted Tephrosia vogelii and Tithonia diversifolia fallow species and natural fallow was conducted at Maseno, Kenya, for assessing whether these fallows grown on a nutrient depleted land could produce sufficient green manure in six month period, whether their biomass retained on the same plots or transferred to continuously cropped plots with or without added P fertiliser could increase yield of consecutive maize crops and whether it is useful to regularly repeat these fallows on same plots. First fallow was established in randomized complete blocks with three replicates. At harvesting, biomass was recorded, then either incorporated in situ or transferred to continuous cropped plots split with and without added P fertiliser and monitored for the effect in improving consecutive maize crops. The second fallow was managed on this split plot design. The two-planted shrubs fallows produced more than 9 Mg total dry biomass and accumulated 154 to 234 kg N.ha-1, which were significantly higher compared to the production in the natural fallow. The shrubs were also superior to natural fallow for P accumulation (5-22 kg versus 2 kg.ha-1. The aboveground dry biomass harvested from planted T. vogelii and T. diversifolia and either incorporated in situ or transferred into continuously cropped plots increased maize yields by 2.5 folds compared to the unmanured crop, the control. Supplementing the organic materials with an additional 20 kg P inorganic fertilizer increased the 1st maize yield by about 40%. Productivity in the plots with T. vogelii or T. diversifolia aboveground biomass removal was low for the subsequent fallow and maize crops when compared to the performance in plots where biomass was incorporated. To achieve sustained yields of maize in depleted soils requires regular improved fallowing at least one season alternating with one season maize, and additional P inputs.

  11. Chitosan/halloysite nanotubes bionanocomposites: structure, mechanical properties and biocompatibility.

    Science.gov (United States)

    Liu, Mingxian; Zhang, Yun; Wu, Chongchao; Xiong, Sheng; Zhou, Changren

    2012-11-01

    Incorporation of nanosized reinforcements into chitosan usually results in improved properties and changed microstructures. Naturally occurred halloysite nanotubes (HNTs) are incorporated into chitosan for forming bionanocomposite films via solution casting. The electrostatic attraction and hydrogen bonding interactions between HNTs and chitosan are confirmed. HNTs are uniformly dispersed in chitosan matrix. The tensile strength and Young's modulus of chitosan are enhanced by HNTs. The storage modulus and glass transition temperature of chitosan/HNTs films also increase significantly. Blending with HNTs induces changes in surface nanotopography and increase of roughness of chitosan films. In vitro fibroblasts response demonstrates that both chitosan and chitosan/HNTs nanocomposite films are cytocompatibility even when the loading of HNTs is 10%. In summary, these results provide insights into understanding of the structural relationships of chitosan/HNTs bionanocomposite films in potential applications, such as scaffold materials in tissue engineering. PMID:22743347

  12. Heavy Metal Removal by Chitosan and Chitosan Composite

    International Nuclear Information System (INIS)

    Radiation grafting of diethyl aminoethyl methacrylate (DEAEMA) on chitosan to impart ion exchange properties and to be used for the separation of metal ions from waste water, was carried out. The effect of experimental conditions such as monomer concentration and the radiation dose on grafting were studied. On using chitosan, grafted chitosan and some chitosan composites in metal ion removal they show high up-take capacity for Cu2+ and lower uptake capacities for the other divalent metal ions used (Zn and Co). Competitive study, performed with solutions containing mixture of metal salts, showed high selectivity for Cu2+ than the other metal ion. Limited grafting of DEAEMA polymer -containing specific functional groups-onto the chitosan backbone improves the sorption performance

  13. Application of organic matter and biofertilizer to improve growth and yield of maize on soil damaged by volcanic ash of Mount Kelud in East Java

    Directory of Open Access Journals (Sweden)

    S. Hardianita

    2015-07-01

    Full Text Available Volcanic ash from the eruption of Mount Kelud in 2014 damaged some agricultural areas grown with maize in Malang of East Java. The purpose of this study was to elucidate the effect of organic fertilizers and biological fertilizers on growth and yield of maize on soils damaged by volcanic ash from the eruption of Mount Kelud. A pot experiment was conducted in the glasshouse of Balitkabi, Kendalpayak, Malang from July 2014 to February 2015. The treatments tested in this study were combinations of three mixtures of soil and volcanic ash (90%:10%, 80%:20%, and 70%:30%, and two doses of biofertilizer (25 and 35 kg / ha. Each treatment was added with 5 t organic matter/ha. A total of 10 kg of each mixture of soil and volcanic ash was placed in a 15 kg plastic pot. Each treatment received 100 kg inorganic fertilizer / kg containing 15% N, 15% P, and 15% K. Three seeds of maize (NK33 variety were planted in each pot and thin to one plant after one week. The experiment was conducted for 14 weeks. The results showed that application of organic matter and biofertilizer did not significantly improve fertility of soil mixed with volcanic ash from the eruption of Mount Kelud. Yield of maize was not significantly improved by the application of organic matter and biofertilizer on soil mixed with volcanic ash. The contents of carbohydrates and proteins in maize seeds were also not affected by application of organic matter and biofertilizer.

  14. Improving the osteogenesis of rat mesenchymal stem cells by chitosan-based-microRNA nanoparticles.

    Science.gov (United States)

    Wu, Guangsheng; Feng, Chao; Hui, Guangyan; Wang, Zhongshan; Tan, Jun; Luo, Lankun; Xue, Peng; Wang, Qintao; Chen, Xiguang

    2016-03-15

    MicroRNAs (miRNAs) play important roles in the osteogenic differentiation of stem cells. However, the application of miRNA in bone regeneration has been limited by its poor stability, low cellular uptake, and undesired immune response. In this study, chitosan (CS)/tripolyphosphate (TPP)/Hyaluronic Acid (HA) nanoparticles (CTH NPs) were prepared to deliver antimiR-138 to bone marrow mesenchymal stem cells (MSCs). The particle size, polydispersity index, and zeta potential of CTH NPs were related to the weight ratio of CS:TPP:HA. At optimum N/P ratio (20:1), the highest encapsulation efficiency was obtained. Both blank CTH NPs and CTH/antmiR-138 NPs exhibited no cytotoxicity to MSCs. A high transfection efficiency (nearly 70%) and significant enhancement of the osteogenesis of MSCs were observed. Above results demonstrated that CTH NPs was a potential candidate as an efficient non-viral miRNA vector to regulate the osteogenic differentiation of MSCs. PMID:26794737

  15. Chitosan hydrogel beads impregnated with hexadecylamine for improved reactive blue 4 adsorption.

    Science.gov (United States)

    Vakili, Mohammadtaghi; Rafatullah, Mohd; Ibrahim, Mahamad Hakimi; Abdullah, Ahmad Zuhairi; Salamatinia, Babak; Gholami, Zahra

    2016-02-10

    Adsorption performance of chitosan (CS) hydrogel beads was investigated after impregnation of CS with hexadecylamine (HDA) as a cationic surfactant, for the elimination of reactive blue 4 (RB4) from wastewater. The CS/HDA beads formed with 3.8% HDA were the most effective adsorbent. The adsorption capacity was increased by 1.43 times from 317 mg/g (CS) to 454 mg/g (CS/HDA). The RB4 removal increased with decrease in the pH of dye solution from 4 to 9. The isotherm data obtained from RB4 adsorption on CS and CS/HDA are adequately described by Freundlich model (R(2)=0.946 and 0.934, χ(2)=22.414 and 64.761). The kinetic study revealed that the pseudo-second-order rate model (R(2)=0.996 and 0.997) was in better agreement with the experimental data. The negative values of ΔG° (-2.28 and -6.30 kJ/mol) and ΔH° (-172.18 and -101.62 kJ/mol) for CS beads and HDA modified CS beads, respectively; suggested a spontaneous and exothermic process for RB4 adsorption. PMID:26686114

  16. Integrated genetic maps of DNA markers and mutations and their utility for improving sorghum and maize

    International Nuclear Information System (INIS)

    The primary goal of this research programme was to develop basic genetic tools for facilitating research in the genetics and breeding of sorghum. The restriction fragment length polymorphism (RFLP) linkage map produced at Iowa State University was created through linkage analysis of 78 F2 plants of an intraspecific cross between inbred CK60 and accession PI229828. The map consists of 201 loci distributed among 10 linkage groups covering 1299 cM. Comparison of sorghum and maize RFLP maps revealed a high degree of conservation, as reflected by homology, copy number and collinearity. Examples of conserved and rearranged locus orders were observed. The same sorghum population was used to map the genetic factors (mutants and quantitative trait loci (QTL)) for several traits, including vegetative and reproductive morphology, maturity, and insect and disease resistance. Analysis of the genetic factors affecting plant height, an important character for sorghum adaptation in temperate latitudes for grain production, is emphasized. Four QTL for plant height were identified in a sample of 152 F2 plants, whereas six QTL were detected among their F3 progeny. These observations and assessments of other traits at four QTL common to the F2 plants and their F3 progeny indicate that some of these regions correspond to loci (dw) previously identified on the basis of alleles with highly qualitative effects. Four of the six sorghum plant height QTL seem to be orthologous to plant height QTL in maize. Other possible instances of orthologous QTL included regions for maturity and tillering. These observations suggest that conservation of the maize and sorghum genomes encompasses sequence homology, collinearity and function. 11 refs, 2 figs

  17. Altered Lignin Biosynthesis Improves Cellulosic Bioethanol Production in Transgenic Maize Plants Down-Regulated for Cinnamyl Alcohol Dehydrogenase

    Institute of Scientific and Technical Information of China (English)

    Silvia Fornalé; Pere Puigdomènech; Joan Rigau; David Caparrós-Ruiz; Montserrat Capellades; Antonio Encina; Kan Wang; Sami Irar; Catherine Lapierre; Katia Ruel; Jean-Paul Joseleau; Jordi Berenguer

    2012-01-01

    Cinnamyl alcohol dehydrogenase(CAD)is a key enzyme involved in the last step of monolignol biosynthesis.The effect of CAD down-regulation on lignin production was investigated through a transgenic approach in maize.Transgenic CAD-RNAi plants show a different degree of enzymatic reduction depending on the analyzed tissue and show alterations in cell wall composition.Cell walls of CAD-RNAi stems contain a lignin polymer with a slight reduction in the S-to-G ratio without affecting the total lignin content.In addition,these cell walls accumulate higher levels of cellulose and arabinoxylans.In contrast,cell walls of CAD-RNAi midribs present a reduction in the total lignin content and of cell wall polysaccharides.In vitro degradability assays showed that,although to a different extent,the changes induced by the repression of CAD activity produced midribs and stems more degradable than wild-type plants.CAD-RNAi plants grown in the field presented a wild-type phenotype and produced higher amounts of dry biomass.Cellulosic bioethanol assays revealed that CAD-RNAi biomass produced higher levels of ethanol compared to wild-type,making CAD a good target to improve both the nutritional and energetic values of maize lignocellulosic biomass.

  18. Towards improved nitrogen management in silage maize production on sandy soils.

    OpenAIRE

    Schroder, J.J.

    1998-01-01

    Maize has become a highly appreciated crop in Dutch dairy farming during the last 25 years. The current cropping technique, however, is associated with a low recovery of soil mineral nitrogen (N) and serious losses of N to the environment. This gave rise to the research described in this thesis which begins by reviewing the literature on the role of N in crop production, on N efficiency and on N losses ( Chapter 1) . The research reported in subsequent chapters had three objectives:to identif...

  19. Improving sustainable intensification of cereal-grain legume cropping systems in the savannahs of West Africa: Quantifying residual effects of legumes on maize, enhancing P mobilization by legumes and studying long-term Soil Organic Matter (SOM) dynamics

    International Nuclear Information System (INIS)

    Improved cereal-grain-legume systems, allowing farmers to use their land productively on a continuous basis, are being rapidly developed and adopted by small-scale farmers in the West African Moist Savannah. This paper summarizes work on several issues related to the improvement of productivity and sustainability of these intensified systems. A first study looked at the sustainability of several legume-maize cropping systems in a 5-year field trial at Sekou, Benin. Fairly low maize yields were found in continuous maize cropping systems (maize/maize), poor response to N fertilizer beyond 45 kg N ha-1, and no evidence that P and K were limiting crop yield. Over the last 5 years of the trial, maize/Mucuna relay cropping gave consistently a 2000 kg ha-1 yield increase relative to maize/maize cropping, and most of this yield gain was preserved even when Mucuna residues were removed from the plots when planting the next year's maize crop. Some yield gain, although far less than with maize/Mucuna, was observed in the maize/pigeon pea system. The maize/cowpea system offered no maize yield gain over maize/maize cropping. In a second study, enhanced isotopic methods to determine the plant available P allowed us to test the hypothesis that certain legume accessions can mobilize sparingly-available P. In one out of the 3 West-African Moist Savannah soils studied, we found that cowpea could access sparingly soluble soil P that is unavailable to maize. This mobilization of P was only observed when P deficiency occurred. These results confirm the P efficiency of some legume genotypes, which may lead to benefits of improved P availability by the incorporation of legumes in rotation systems. A third study, involving a 16-year continuous-cropping field experiment in Ibadan, Nigeria, provided information on long-term changes in soil organic matter carbon (SOC) contents in savannah soils with sandy top soil. In the control treatments with continuous maize and cowpea cropping without

  20. Improved wettability and adhesion of polylactic acid/chitosan coating for bio-based multilayer film development

    Science.gov (United States)

    Gartner, Hunter; Li, Yana; Almenar, Eva

    2015-03-01

    The objective of this study was to investigate the effect of methyldiphenyl diisocyanate (MDI) concentration (0, 0.2, 1, 2, and 3%) on the wettability and adhesion of blend solutions of poly(lactic acid) (PLA) and chitosan (CS) when coated on PLA film for development of a bio-based multi-layer film suitable for food packaging and other applications. Characterization was carried out by attenuated total reflectance infrared spectrometry (ATR-FTIR), contact angle (θ), mechanical adhesion pull-off testing, and scanning electron microscopy (SEM). The θ of the PLA/CS blend shifted to a lower value (41-35°) with increasing MDI concentration showing that the surface tension was modified between the PLA/CS blend solution and PLA film and better wettability was achieved. The increase in MDI also resulted in an increased breaking strength (228-303 kPa) due to the increased H-bonding resulting from the more urethane groups formed within the PLA/CS blend as shown by ATR-FTIR. The improved adhesion was also shown by the increased number of physical entanglements observed by SEM. It can be concluded that MDI can be used to improve wettability and adhesion between PLA/CS coating and PLA film.

  1. Engineering interfacial properties by anionic surfactant-chitosan complexes to improve stability of oil-in-water emulsions.

    Science.gov (United States)

    Zinoviadou, Kyriaki G; Scholten, Elke; Moschakis, Thomas; Biliaderis, Costas G

    2012-03-01

    Oil-in-water emulsions (10% w/w n-tetradecane) were prepared at pH = 5.7 by using, as surface active agents, electrostatically formed complexes of sodium stearoyl lactylate (SSL) at a concentration of 0.4% (w/w) and chitosan (CH) in a concentration range between 0 and 0.48% w/w. The use of complexes in emulsions with a low concentration of CH (gel-like behavior since in all cases the G' (storage modulus) was lower that G'' (loss modulus). Adsorption kinetics of pure SSL and SSL/CH complexes to the oil/water interfaces were evaluated using an automated drop tensiometer (ADT). Even though complexation of SSL with CH resulted in a delay of the adsorption of the surface active species at the oil/water interface, the inclusion of the polysaccharide resulted in substantially improved interfacial properties as indicated by a significant increase of the dilatational modulus. Furthermore, the enhanced interfacial properties of the emulsion droplets resulted in improved stability against freeze-thaw cycling. The results of this study may facilitate the development of frozen food products such as desserts with an ameliorated stability and favorable sensorial characteristics. PMID:22298029

  2. Improvement to Maize Growth Caused by Biochars Derived From Six Feedstocks Prepared at Three Different Temperatures

    Institute of Scientific and Technical Information of China (English)

    LUO Yu; JIAO Yu-jie; ZHAO Xiao-rong; LI Gui-tong; ZHAO Li-xin; MENG Hai-bo

    2014-01-01

    Biochar is increasingly proposed as a soil amendment, with reports of benefits to soil physical, chemical and biological properties. In this study, different biochars were produced from 6 feedstocks, including straw and poultry manure, at 3 pyrolysis temperatures (200, 300 and 500°C) and then added separately to a calcareous soil. Their effects on soil properties and maize growth were evaluated in a pot experiment. The biochars derived from crop straw had much higher C but smaller N concentrations than those derived from poultry manure. Carbon concentrations, pH and EC values increased with increasing pyrolysis temperature. Biochar addition resulted in increases in mean maize dry matter of 12.73%and NPK concentrations of 30, 33 and 283%, respectively. Mean soil pH values were increased by 0.45 units. The biochar-amended soils had 44, 55, 254 and 537%more organic C, total N, Olsen-P and available K, respectively, than the control on average. Both feedstocks and pyrolysis temperature determined the characteristics of the biochar. Biochars with high mineral concentrations may act as mineral nutrient supplements.

  3. Encapsulation of selenium in chitosan nanoparticles improves selenium availability and protects cells from selenium-induced DNA damage response

    Science.gov (United States)

    Selenium, an essential mineral, plays important roles in optimizing human health. Chitosan is an effective, naturally oriented material for synthesizing nanoparticles with polyanions and exhibit preferable properties such as biocompatibility, biodegradation and resistance to certain enzymes. We have...

  4. Improvement of the microbiological quality of ready-to-eat peeled shrimps (Penaeus vannamei) by the use of chitosan coatings.

    Science.gov (United States)

    Carrión-Granda, Ximena; Fernández-Pan, Idoya; Jaime, Isabel; Rovira, Jordi; Maté, Juan I

    2016-09-01

    Chitosan coatings incorporated with 0.5% of oregano and thyme EO were applied onto ready-to-eat peeled shrimp tails and packed under MAP conditions. The growth of naturally present spoilage microorganisms was evaluated for 12days during chilled storage (4°C). Coatings containing thyme EO were more effective in inhibiting the microbial species studied, specially lactic acid and psychrotrophic bacteria. As carrier of EOs, chitosan was more effective in inhibiting the growth of bacteria present in peeled shrimps than the direct application of an oil-water (O/W) emulsion. Finally, results from sensory analysis showed that the sensorial quality was affected by the chitosan-thyme coatings despite characteristics like firmness and colour were kept. The present work demonstrates the effectiveness of chitosan enriched coatings, offering a promising alternative to control the growth of spoilage and pathogen microorganisms on peeled shrimps during refrigeration storage. PMID:27315588

  5. Maize databases

    Science.gov (United States)

    This chapter is a succinct overview of maize data held in the species-specific database MaizeGDB (the Maize Genomics and Genetics Database), and selected multi-species data repositories, such as Gramene/Ensembl Plants, Phytozome, UniProt and the National Center for Biotechnology Information (NCBI), ...

  6. Improving bone marrow stromal cell attachment on chitosan/hydroxyapatite scaffolds by an immobilized RGD peptide

    International Nuclear Information System (INIS)

    Ample cell adhesion to scaffolds is essential for effective bone tissue engineering. Chitosan/hydroxyapatite (CS/HA) scaffolds with channel-shaped and spherically shaped pore morphologies were prepared via in situ compositing hybridization in combination with lyophilization. The sizes of channel-shaped and spherically shaped pores of the CS/HA scaffolds were 150-650 μm and 3-15 μm, respectively. The RGD peptide (Arg-Gly-Asp) was bound to the surface of CS/HA scaffolds via physical adsorption. More than 63% of RGD present in a PBS solution spontaneously adsorbed onto CS/HA scaffolds. High numbers of viable bone marrow stromal cells (BMSCs) were observed by confocal and fluorescence microscopy for cells cultured on CS/HA scaffolds with and without RGD for 3 days. BMSCs on CS/HA scaffolds with RGD (RGD-CS/HA) were incubated for 4 h under standard culture conditions, and the degree of cell adhesion was calculated. Cell adhesion to RGD-CS/HA scaffolds with different RGD concentrations was 71.6% and 80.7%, respectively. This was 30.9% and 47.5% higher than adhesion to the CS/HA scaffold without RGD, respectively. BMSCs cultured on the scaffolds for 14 days with osteogenic supplements expressed 103% higher alkaline phosphatase on the RGD-CS/HA scaffold (0.001 97 ± 0.000 31 U/L/ng), than on the unmodified scaffold (0.000 97 ± 0.000 25 U/L/ng) (p < 0.01), indicating that a RGD peptide significantly promotes osteogenic differentiation of BMSCs on CS/HA scaffolds. The results of this study indicate that RGD-CS/HA scaffolds promote initial cell adhesion, spread and differentiation toward an osteogenic phenotype.

  7. Prof. Wang Jie Met with the Chair of Board of Trustees and the Director General of International Maize and Wheat Improvement Center

    Institute of Scientific and Technical Information of China (English)

    Zhang Yongtao

    2007-01-01

    @@ On April 10, 2007, Prof. Wang Jie, Vice President of NSFC, met with the delegation from International Maize and Wheat Improvement Center (CIMMYT), headed by its Chair of Board of Trustees Prof. Lene Lange and the Director General Prof. Masa Iwanaga.

  8. Chitosan as an adjuvant for poliovaccine.

    Science.gov (United States)

    Ghendon, Y; Markushin, S; Akopova, I; Koptiaeva, I; Krivtsov, G

    2011-05-01

    The use of inactivated poliomyelitis vaccine is very important for eradicating poliomyelitis. However, this vaccine is not available readily in underdeveloped countries due to the high cost. Adjuvants can improve the immunogenicity of a vaccine and reduce the antigen dose required for vaccination, thus lowering the cost of the vaccine. Chitosan glutamate solution and a chitosan sulfate micro/nanoparticle suspension were tested as adjuvants for Imovax-inactivated poliovaccine and for inactivated monovalent poliovirus type 1, 2, and 3 vaccines obtained by inactivation of the attenuated Sabin poliovirus strains. Inactivated vaccines admixed with either chitosan glutamate or chitosan sulfate micro/nanoparticles and administered to mice showed significantly enhanced immunogenicity to poliovirus type 1, 2, and 3 strains compared to the respective vaccines administered without chitosan. Chitosan preparations increased the immunogenicity of 1:2 and 1:4 diluted inactivated Sabin strain preparations in mice 8- to 16-fold, so that the neutralizing antibody titers after vaccination with adjuvanted diluted vaccine were equal to those obtained after vaccination with undiluted vaccine administered without chitosan. Neutralizing antibodies could be detected in sera of rats vaccinated with undiluted, 1:10, and 1:100 diluted Imovax vaccine admixed with chitosan sulfate micro/nanoparticles, although in the control group, vaccination only with the undiluted vaccine resulted in antibody production. These results show that the chitosan glutamate solution and chitosan sulfate micro/nanoparticle suspension can significantly improve the immunogenicity of various poliovaccines, and reduce the effective antigen dose. PMID:21412793

  9. Improved wettability and adhesion of polylactic acid/chitosan coating for bio-based multilayer film development

    Energy Technology Data Exchange (ETDEWEB)

    Gartner, Hunter [School of Packaging, Michigan State University, East Lansing, Michigan (United States); Li, Yana [Mechanical Engineering College, Wuhan Polytechnic University (China); Almenar, Eva, E-mail: ealmenar@msu.edu [School of Packaging, Michigan State University, East Lansing, Michigan (United States)

    2015-03-30

    Graphical abstract: - Highlights: • Surface tension between PLA/CS blend solution and PLA film modified by MDI. • Better wettability between PLA/CS blend solution and PLA film by increasing MDI. • Increased breaking strength by increasing MDI due to the increased H-bonding. • Increased number of physical entanglements between PLA/CS coating and PLA film. • Development of a suitable bio-based multilayer film for food packaging applications. - Abstract: The objective of this study was to investigate the effect of methyldiphenyl diisocyanate (MDI) concentration (0, 0.2, 1, 2, and 3%) on the wettability and adhesion of blend solutions of poly(lactic acid) (PLA) and chitosan (CS) when coated on PLA film for development of a bio-based multi-layer film suitable for food packaging and other applications. Characterization was carried out by attenuated total reflectance infrared spectrometry (ATR-FTIR), contact angle (θ), mechanical adhesion pull-off testing, and scanning electron microscopy (SEM). The θ of the PLA/CS blend shifted to a lower value (41–35°) with increasing MDI concentration showing that the surface tension was modified between the PLA/CS blend solution and PLA film and better wettability was achieved. The increase in MDI also resulted in an increased breaking strength (228–303 kPa) due to the increased H-bonding resulting from the more urethane groups formed within the PLA/CS blend as shown by ATR-FTIR. The improved adhesion was also shown by the increased number of physical entanglements observed by SEM. It can be concluded that MDI can be used to improve wettability and adhesion between PLA/CS coating and PLA film.

  10. Improved wettability and adhesion of polylactic acid/chitosan coating for bio-based multilayer film development

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Surface tension between PLA/CS blend solution and PLA film modified by MDI. • Better wettability between PLA/CS blend solution and PLA film by increasing MDI. • Increased breaking strength by increasing MDI due to the increased H-bonding. • Increased number of physical entanglements between PLA/CS coating and PLA film. • Development of a suitable bio-based multilayer film for food packaging applications. - Abstract: The objective of this study was to investigate the effect of methyldiphenyl diisocyanate (MDI) concentration (0, 0.2, 1, 2, and 3%) on the wettability and adhesion of blend solutions of poly(lactic acid) (PLA) and chitosan (CS) when coated on PLA film for development of a bio-based multi-layer film suitable for food packaging and other applications. Characterization was carried out by attenuated total reflectance infrared spectrometry (ATR-FTIR), contact angle (θ), mechanical adhesion pull-off testing, and scanning electron microscopy (SEM). The θ of the PLA/CS blend shifted to a lower value (41–35°) with increasing MDI concentration showing that the surface tension was modified between the PLA/CS blend solution and PLA film and better wettability was achieved. The increase in MDI also resulted in an increased breaking strength (228–303 kPa) due to the increased H-bonding resulting from the more urethane groups formed within the PLA/CS blend as shown by ATR-FTIR. The improved adhesion was also shown by the increased number of physical entanglements observed by SEM. It can be concluded that MDI can be used to improve wettability and adhesion between PLA/CS coating and PLA film

  11. Exploration of agro-ecological options for improving maize-based farming systems in Costa Chica, Guerrero, Mexico

    OpenAIRE

    Flores Sanchez, D.

    2013-01-01

    Keywords: farm diagnosis, farming systems, soil degradation, intercropping, maize, roselle, legumes, nutrient management, vermicompost, crop residues, decomposition, explorations.   In the Costa Chica, a region of Southwest Mexico, farming systems are organized in smallholder units. The dominant cropping systems are based on maize (Zea mays L.), either as monocrop or intercropped with roselle (Hibiscus sabdariffa L.). Continuous cropping, and unbalanced fertilizer management systems with...

  12. Use of wheat and maize protein mutants in breeding for improved protein quantity and quality

    International Nuclear Information System (INIS)

    Selected offspring progenies (50 mutant lines) originating from mutation experiments with hexaploid wheat (cv. Bezostaya 1) were analysed for induced heritable variation in protein content, lysine content, grain yield and protein and lysine yields. Ten of these mutant lines were crossed with 11 local varieties. The protein and lysine contents were measured in the progenies of these crossings. The data showed better correlations of grain yield with protein and lysine yields than the protein and lysine contents with their corresponding yields. F1 seeds showed higher lysine and protein contents than local varieties. Data with maize showed that: (1) the total endosperm protein content of modified opaque-2 types increases with an increase in the degree of normalization; (2) the lysine content in dry matter and protein in normalized o2 kernels usually decreases with the increasing degree of normalization; (3) the lysine content in protein of modified o2 kernels, is, in general, satisfactory up to the normalization of about 50% of endosperm. A desirable modification of o2 endosperm within line A632o2 was selected and crossed with o2 lines. Most of the tested hybrids had a good protein quality, but endosperm modification was not evident in all hybrids. The o2 gene was incorporated into high protein backgrounds. Besides a high protein content and quality, some of the hybrids tested had a comparable or higher yield than the o2 check. (author)

  13. Blood protein adsorption onto chitosan

    OpenAIRE

    Benesch, Johan; Tengvall, P.

    2002-01-01

    Chitosan was recently indicated to enhance osteogenesis, improve wound healing but to activate the coagulation and the complement systems. In the present study approximately 10nm thick chitosan film were prepared on aminopropyltriethoxysilane (APTES) coated silicon. The surfaces were incubated in serum or plasma and subsequently in antibodies towards key complement and contact activation of coagulation proteins. The deposited amounts were compared with those on hydrophilic and hydrop...

  14. A review on chitosan-cellulose blends and nanocellulose reinforced chitosan biocomposites: Properties and their applications.

    Science.gov (United States)

    H P S, Abdul Khalil; Saurabh, Chaturbhuj K; A S, Adnan; Nurul Fazita, M R; Syakir, M I; Davoudpour, Y; Rafatullah, M; Abdullah, C K; M Haafiz, M K; Dungani, R

    2016-10-01

    Chitin is one of the most abundant natural polymers in world and it is used for the production of chitosan by deacetylation. Chitosan is antibacterial in nature, non-toxic, and biodegradable thus it can be used for the production of biodegradable film which is a green alternative to commercially available synthetic counterparts. However, their poor mechanical and thermal properties restricted its wide spread applications. Chitosan is highly compatible with other biopolymers thus its blending with cellulose and/or incorporation of nanofiber isolated from cellulose namely cellulose nanofiber and cellulose nanowhiskers are generally useful. Cellulosic fibers in nano scale are attractive reinforcement in chitosan to produce environmental friendly composite films with improved physical properties. Thus chitosan based composites have wide applicability and potential in the field of biomedical, packaging and water treatment. This review summarises properties and preparation procedure of chitosan-cellulose blends and nano size cellulose reinforcement in chitosan bionanocomposites for different applications. PMID:27312632

  15. Blood contact properties of ascorbyl chitosan.

    Science.gov (United States)

    Yalinca, Z; Yilmaz, E; Taneri, B; Bullici, F; Tuzmen, S

    2013-01-01

    Ascorbyl chitosan was synthesized by heating chitosan with ascorbic acid in isopropanol. The products were characterized by FTIR and C-13 NMR spectroscopies, SEM, and elemental analysis. Blood contact properties of ascorbyl chitosans were evaluated. The ascorbyl chitosans demonstrated to have increased lipid-lowering activity in comparison to chitosan alone upon contact with human blood serum in in vitro conditions. Furthermore, the total cholesterol/HDL ratio was improved towards the desirable ideal values after three hours contact with ascorbyl chitosan samples. The lipid-lowering activity increased with ascorbyl substitution. The inherent nonspecific adsorption capability of chitosan due to its chelating power with several different functional groups was exhibited by ascorbyl chitosans as well. This behavior was exemplified in a simultaneous decrease in the total iron values of the volunteers together with lower lipid levels. Furthermore, ascorbyl chitosans were observed to have less hemocompatibility but increased anticoagulant activity when compared to chitosan alone. Additional in vivo studies are necessary to support these results and to investigate further the advantages and disadvantages of these materials to prove their safety prior to clinical applications. PMID:23862665

  16. Chitosan composite films. Biomedical applications.

    Science.gov (United States)

    Cárdenas, Galo; Anaya, Paola; von Plessing, Carlos; Rojas, Carlos; Sepúlveda, Jackeline

    2008-06-01

    Chitosan acetate films have been prepared using chitosans from shrimps (Pleuroncodes monodon) of low and high molecular weight (LMv = 68,000 g/mol and HMv = 232,000 g/mol) and deacetylation degree of 80 and 100%, respectively. The chitosan films were obtained by addition of several additives to acetic acid chitosan solutions, such as: glycerol, oleic acid and linoleic acid in different proportions. The pH of the solutions before casting ranged from 5.0 to 6.0. The composite film thickness are reported. The films have been analyzed by FTIR showing characteristic bands corresponding to the additives. The scanning electron microscopy (SEM) studies reveals the different morphology of the composite films. The films exhibit different physical properties depending upon the additives and/or mixture of them. The addition of glycerol to composite improves the elasticity of the films. The swelling in glucose and saline solutions for several films was evaluated, being higher in the glucose solution. The bactericide test against Staphylococcus aureus, Pseudomona aeruginosa and Acinetobacter baumanii in plates with either blood and or agar tripticase showed that the molecular weight influences on the bactericidal properties of the chitosan composite films and over its effect against gram positive and gram negative bacteria. Medical applications of the composite films were done in patients with burns, ulcers and injuries, the films containing glycerol showed good adhesion in comparison with those without it. The composite films tested were mainly three (1) chitosan acetate with glycerol, (2) chitosan acetate with oleic acid and (3) chitosan acetate with glycerol and oleic acid. Excellent results in the skin recovery were obtained after 7-10 days. Since the chitosan is biodegradable by the body enzymes it does not need to be removed and increases the gradual grows of the damage tissues. PMID:18165888

  17. Liposomes coated with N-trimethyl chitosan to improve the absorption of harmine in vivo and in vitro.

    Science.gov (United States)

    Chen, Wei-Liang; Yuan, Zhi-Qiang; Liu, Yang; Yang, Shu-di; Zhang, Chun-ge; Li, Ji-Zhao; Zhu, Wen-jing; Li, Fang; Zhou, Xiao-feng; Lin, Yi-mei; Zhang, Xue-nong

    2016-01-01

    In this study, harmine liposomes (HM-lip) were prepared through the thin-film hydration-pH-gradient method and then coated with N-trimethyl chitosan (TMC). Particle size, zeta potential, entrapment efficiency, and in vitro release of HM-lip and TMC-coated harmine liposomes (TMC-HM-lip) were also determined. Sprague Dawley rats were further used to investigate the pharmacokinetics in vivo. Retention behavior in mouse gastrointestinal tract (GIT) was studied through high-performance liquid chromatography and near-infrared imaging. Degradation was further evaluated through incubation with Caco-2 cell homogenates, and a Caco-2 monolayer cell model was used to investigate the uptake and transport of drugs. HM-lip and TMC-HM-lip with particle size of 150-170 nm, an entrapment efficiency of about 81%, and a zeta potential of negative and positive, respectively, were prepared. The release of HM from HM-lip and TMC-HM-lip was slower than that from HM solution and was sensitive to pH. TMC-HM-lip exhibited higher oral bioavailability and had prolonged retention time in GIT. HM-lip and TMC-HM-lip could also protect HM against degradation in Caco-2 cell homogenates. The uptake amount of TMC-HM-lip was higher than that of HM and HM-lip. TMC-HM-lip further demonstrated higher apparent permeability coefficient (P(app)) from the apical to the basolateral side than HM and HM-lip because of its higher uptake and capability to open tight junctions in the cell monolayers. TMC-HM-lip can prolong the retention time in the GIT, protect HM against enzyme degradation, and improve transport across Caco-2 cell monolayers, thus enhancing the oral bioavailability of HM. PMID:26855571

  18. Integrated application of February Orchid (Orychophragmus violaceus) as green manure with chemical fertilizer for improving grain yield and reducing nitrogen losses in spring maize system in northern China

    Institute of Scientific and Technical Information of China (English)

    BAI Jin-shun; CAO Wei-dong; XIONG Jing; ZENG Nao-hua; GAO Song-juan; Shimizu Katsuyoshi

    2015-01-01

    The development of more efifcient management systems is crucial to achieving high grain yields with high nitrogen use efifciency (NUE). February Orchid-spring maize rotation system is a newly established planting system with the beneifts of ground cover and potential wind erosion in northern China. A ifeld experiment was conducted to evaluate the effects of integrated application of February Orchid as green manure with reduction of chemical fertilizers (INTEGRATED) on spring maize yield, N uptake, ammonium volatilization, and soil residual mineral N in northern China. Compared to farmers’ traditional fertilization (CON), integrated application of February Orchid as green manure with 30% reduction of nitrogen fertilizers (INTEGRATED) increased maize grain yield and biomass by 9.9 and 10.2%, respectively. The 0–100 cm soil residual Nmin at harvest was decreased by 58.5% and thus nitrogen use efifciency was increased signiifcantly by 26.7%. The nitrogen balance calculation further demonstrated that the INTEGRATED approach performed better than CON with lower apparent nitrogen loss (decreased by 48.9%) which evidenced by the ammonium volatilization of top-dressing fertilizer was decreased by 31.1%, the Nmin movement to the deeper soil layers was reduced, and the apparent nitrogen leaching loss nearly equal to 0 under the INTEGRATED treatment. Therefore, in northern China, integrated application of green manure and chemical fertilizers is an efifcient management approach for improving maize yields and NUE simultaneously.

  19. Characterization of chitosan composites with various clays.

    Science.gov (United States)

    Lewandowska, Katarzyna; Sionkowska, Alina; Kaczmarek, Beata; Furtos, Gabriel

    2014-04-01

    The structural properties, thermal behaviour and mechanical properties of composites of chitosan (Ch) with nanoclay (montmorillonite, MMT) and/or nanoclays after surface modification have been characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA) and a tensile tests. The microstructure obtained by SEM and AFM microscopy for unmodified chitosan and its composites showed that particles are relatively well dispersed in the chitosan matrix. However, the increasing concentration of the chitosan solution from 1% to 2% decreases the homogeneity of the surface of the composites. In the case of chitosan composite with modified nanoclay (contains 25-30 wt.% of octadecylamine), the lack of particles aggregates in polymer matrix independent of the concentration of chitosan solution was observed. Generally, addition of nanoclay after its surface modification improved the mechanical and thermal properties of the composite much more than montmorillonite without modification. PMID:24530323

  20. Improving the controlled delivery formulations of caffeine in alginate hydrogel beads combined with pectin, carrageenan, chitosan and psyllium.

    Science.gov (United States)

    Belščak-Cvitanović, Ana; Komes, Draženka; Karlović, Sven; Djaković, Senka; Spoljarić, Igor; Mršić, Gordan; Ježek, Damir

    2015-01-15

    Alginate-based blends consisting of carrageenan, pectin, chitosan or psyllium husk powder were prepared for assessment of the best formulation aimed at encapsulation of caffeine. Alginate-pectin blend exhibited the lowest viscosity and provided the smallest beads. Alginate-psyllium husk blend was characterised with higher viscosity, yielding the largest bead size and the highest caffeine encapsulation efficiency (83.6%). The release kinetics of caffeine indicated that the porosity of alginate hydrogel was not reduced sufficiently to retard the diffusion of caffeine from the beads. Chitosan coated alginate beads provided the most retarded release of caffeine in water. Morphological characteristics of beads encapsulating caffeine were adversely affected by freeze drying. Bitterness intensity of caffeine-containing beads in water was the lowest for alginate-psyllium beads and chitosan coated alginate beads. Higher sodium alginate concentration (3%) for production of hydrogel beads in combination with psyllium or chitosan coating would present the most favourable carrier systems for immobilization of caffeine. PMID:25149001

  1. Preparation, characterization and antibacterial activity of chitosan and phosphorylated chitosan from cuttlebone of Sepia kobiensis (Hoyle, 1885)

    OpenAIRE

    Annaian Shanmugam; Kandasamy Kathiresan; Lakshman Nayak

    2016-01-01

    Chitosan is a commercially available derivative of chitin that has been extensively studied for its antimicrobial properties. In order to improve the water solubility and its biological activity, the chemical modification or derivatisation is attempted. In the present investigation, the chitosan prepared from the cuttlebone of Sepia kobiensis was being chemically modified by reacting it with orthophosphoric acid so as to obtain phosphorylated chitosan. Then the chitosan and phosphorylated chi...

  2. Exploration of agro-ecological options for improving maize-based farming systems in Costa Chica, Guerrero, Mexico

    NARCIS (Netherlands)

    Flores Sanchez, D.

    2013-01-01

    Keywords: farm diagnosis, farming systems, soil degradation, intercropping, maize, roselle, legumes, nutrient management, vermicompost, crop residues, decomposition, explorations.   In the Costa Chica, a region of Southwest Mexico, farming systems are organized in smallholder

  3. Improved stability and skin permeability of sodium hyaluronate-chitosan multilayered liposomes by Layer-by-Layer electrostatic deposition for quercetin delivery.

    Science.gov (United States)

    Jeon, Soha; Yoo, Cha Young; Park, Soo Nam

    2015-05-01

    Layer-by-Layer (LbL) technology, based on the electrostatic interaction of polyelectrolytes, is used to improve the stability of drug delivery systems. In the present study, we developed multilayered liposomes with up to 10 alternating layers based on LbL deposition of hyaluronate-chitosan for transdermal delivery. Dihexadecyl phosphate was used to provide liposomes with a negative charge; the liposomes were subsequently coated with cationic chitosan (CH) followed by anionic sodium hyaluronate (HA). The resulting particles had a cumulative size of 528.28±29.22nm and an alternative change in zeta potential. Differential scanning calorimetry (DSC) and transmission electron microscopy (TEM) revealed that the multilayered liposomes formed a spherical polyelectrolyte complex (PEC) after deposition. Observations in size distribution after 1 week found that the particles coated with even layers of polyelectrolytes, hyaluronate and chitosan (HA-CH), were more stable than the odd layers. Membrane stability in the presence of the surfactant Triton X-100 increased with an increase in bilayers as compared to uncoated liposomes. An increase in the number of bilayers deposited on the liposomal surface resulted in a sustained release of quercetin, with release kinetics that fit the Korsmeyer-Peppas model. In an in vitro skin permeation study, negatively charged (HA-CH)-L and positively charged CH-L were observed to have similar skin permeability, which were superior to uncoated liposomes. These results indicate that multilayered liposomes properly coated with polyelectrolytes of HA and CH by electrostatic interaction improve stability and can also function as potential drug delivery system for the transdermal delivery of the hydrophobic antioxidant quercetin. PMID:25819360

  4. CO/sub 2/ enrichment improves recovery of growth and photosynthesis from drought and nitrogen stress in maize

    International Nuclear Information System (INIS)

    In the context of the increasing risk of extreme drought as a result of climate change and increasing CO/sub 2/ in the future of northwest China, evaluation of crops ability to recover and survive droughts requires further attention. To test the effects of re-watering on plants suffering water and nitrogen limitations in the presence of elevated CO/sub 2/, maize (Zea mays) was planted to experience combined elevated CO/sub 2/ (380 or 750 micro mol/sup -1/, climate chamber), water stress (15% PEG-6000) and nitrogen limitation (5 or 15mM N in Hoagland solutions) and then re-watered at three levels (300mL, 600mL, 900mL per pot of distilled water). When plants were re-watered, drought stressed and N limited plants with ambient CO/sub 2/ increased their water content more than that of elevated CO/sub 2/, while the enhancement of growth rate were negatively related to the increasing plant water content. Elevated CO/sub 2/ could help re-watered seedlings to have higher photosynthetic capacity (Fv/Fm, PSII, Pn,Pn/Tr and Pn/Gs) and new leaf growth under low water content, apart from nitrogen deficiency. The results demonstrated that elevated CO2 could help drought stressed seedlings to maintain higher carbon assimilation rates under low water content, as a result to improve leaf water use efficiency. (author)

  5. Nanoindentation of Chitosan Doped with Silver Nanoparticles

    Science.gov (United States)

    Palumbo, Matthew; Teklu, Alem; Kuthirummal, Narayanan; Levi-Polyachenko, Nicole; Department of Physics; Astronomy, College of Charleston Collaboration; Department of Plastic; Reconstructive Surgery, Wake Forest University Health Sciences Collaboration

    Imaging and spectroscopic analysis via nanoindentation was performed with the Nanosurf EasyScan2 AFM on the pure and silver doped chitosan samples allowing for a more localized determination of their stiffness, hardness, and reduced Young's modulus. The pure chitosan sample was tested to have a stiffness of 0.367 N/m, a hardness of 1.12 GPa, and a reduced Young's modulus of 30.5 MPa. The film with 5mg Ag nanoparticle per gram of chitosan was tested on the boundaries between the chitosan and Ag nanoparticles to show an increase in stiffness of about 4.6% at 0.384 N/m, an increase in hardness of about 5.4% at 1.18 GPa, and an increase in the reduced Young's modulus of about 5.0% at 3.2 MPa in comparison to the pure chitosan sample. On the other hand, upon increasing the doping to 10mg Ag nanoparticle per gram of chitosan showed a decrease in stiffness of about 6.3% at 0.344 N/m, a decrease in hardness of about 27.0% at 0.820 GPa, and a decrease in the reduced Young's modulus of about 6.0% at 28.7 MPa in comparison to the pure chitosan sample. Obviously, films doped with 5mg Ag nanoparicle per gram of chitosan provided the composites with improved mechanical strength compared to chitosan alone.

  6. Chitosan/siCkip-1 biofunctionalized titanium implant for improved osseointegration in the osteoporotic condition.

    Science.gov (United States)

    Zhang, Li; Wu, Kaimin; Song, Wen; Xu, Haiyan; An, Ran; Zhao, Lingzhou; Liu, Bin; Zhang, Yumei

    2015-01-01

    Biofunctionalization with siRNA targeting the key negative modulators of bone turnover involved in the molecular mechanism of osteoporosis, such as casein kinase-2 interacting protein-1 (Ckip-1), may lead to enhanced Ti osseointegration in the osteoporotic condition. In this study, even siRNA loading was accomplished by the thermal alkali (TA) treatment to make the Ti ultrahydrophilic and negatively charged to facilitate the physical adsorption of the positively charged CS/siR complex, designated as TA-CS/siR. The intracellular uptake of the CS/siR complex and the gene knockdown efficiency were assessed with bone marrow mesenchymal stem cells (MSCs) as well as the green fluorescent protein (GFP) expressing H1299 cells. In vitro osteogenic activity of TA-CS/siCkip-1 targeting Ckip-1 was assessed with MSCs. In vivo osseointegration of TA-CS/siCkip-1 was assessed in the osteoporotic rat model. TA-CS/siR showed excellent siRNA delivery efficiency and gene silencing effect. TA-CS/siCkip-1 significantly improved the in vitro osteogenic differentiation of MSCs in terms of the enhanced alkaline phosphatase and collagen product and extracellular matrix mineralization, and led to dramatically enhanced in vivo osseointegration in the osteoporostic rat model, showing promising clinical potential for the osteoporotic condition application. TA-CS/siR may constitute a general approach for developing the advanced Ti implants targeting specific molecular mechanism. PMID:26040545

  7. Liposomes coated with N-trimethyl chitosan to improve the absorption of harmine in vivo and in vitro

    Directory of Open Access Journals (Sweden)

    Chen WL

    2016-01-01

    Full Text Available Wei-liang Chen,1,* Zhi-Qiang Yuan,1,* Yang Liu,1 Shu-di Yang,1 Chun-ge Zhang,1 Ji-zhao Li,1 Wen-jing Zhu,1 Fang Li,1 Xiao-feng Zhou,2,3 Yi-mei Lin,4 Xue-nong Zhang1 1Department of Pharmaceutics, College of Pharmaceutical Sciences, 2Department of Radiobiology, College of Radiological Medicine and Protection, Soochow University, Suzhou, 3Changshu Hospital of Traditional Chinese Medicine, Changshu, 4The Second Affiliated Hospital of Xinjiang Medical University, Urumqi, People’s Republic of China *These authors contributed equally to this work Abstract: In this study, harmine liposomes (HM-lip were prepared through the thin-film hydration–pH-gradient method and then coated with N-trimethyl chitosan (TMC. Particle size, zeta potential, entrapment efficiency, and in vitro release of HM-lip and TMC-coated harmine liposomes (TMC-HM-lip were also determined. Sprague Dawley rats were further used to investigate the pharmacokinetics in vivo. Retention behavior in mouse gastrointestinal tract (GIT was studied through high-performance liquid chromatography and near-infrared imaging. Degradation was further evaluated through incubation with Caco-2 cell homogenates, and a Caco-2 monolayer cell model was used to investigate the uptake and transport of drugs. HM-lip and TMC-HM-lip with particle size of 150–170 nm, an entrapment efficiency of about 81%, and a zeta potential of negative and positive, respectively, were prepared. The release of HM from HM-lip and TMC-HM-lip was slower than that from HM solution and was sensitive to pH. TMC-HM-lip exhibited higher oral bioavailability and had prolonged retention time in GIT. HM-lip and TMC-HM-lip could also protect HM against degradation in Caco-2 cell homogenates. The uptake amount of TMC-HM-lip was higher than that of HM and HM-lip. TMC-HM-lip further demonstrated higher apparent permeability coefficient (Papp from the apical to the basolateral side than HM and HM-lip because of its higher uptake and

  8. Engineering interfacial properties by anionic surfactant-chitosan complexes to improve stability of oil-in-water emulsions

    NARCIS (Netherlands)

    Zinoviadou, K.; Scholten, E.; Moschakis, T.; Biliaderis, C.G.

    2012-01-01

    Oil-in-water emulsions (10% w/w n-tetradecane) were prepared at pH = 5.7 by using, as surface active agents, electrostatically formed complexes of sodium stearoyl lactylate (SSL) at a concentration of 0.4% (w/w) and chitosan (CH) in a concentration range between 0 and 0.48% w/w. The use of complexes

  9. Antimicrobial Actions of Degraded and Native Chitosan against Spoilage Organisms in Laboratory Media and Foods

    OpenAIRE

    Rhoades, J.; Roller, S

    2000-01-01

    The objective of this study was to determine whether chitosan (poly-β-1,4-glucosamine) and hydrolysates of chitosan can be used as novel preservatives in foods. Chitosan was hydrolyzed by using oxidative-reductive degradation, crude papaya latex, and lysozyme. Mild hydrolysis of chitosan resulted in improved microbial inactivation in saline and greater inhibition of growth of several spoilage yeasts in laboratory media, but highly degraded products of chitosan exhibited no antimicrobial activ...

  10. Infiltration and planting pits for improved water management and maize yield in semi-arid Zimbabwe

    NARCIS (Netherlands)

    Nyakudya, I.W.; Stroosnijder, L.; Nyagumbo, I.

    2014-01-01

    Realising that rainwater harvesting (RWH) improves crop productivity, smallholder farmers in semi-arid Zimbabwe modified contour ridges traditionally used for rainwater management by digging infiltration pits inside contour ridge channels in order to retain more water in crop fields. However, scient

  11. Ensuring Improved Livelihood Opportunities for Resource-Poor Maize Farmers through the Dissemination of Striga Control Methods in Kwara State, Nigeria

    Directory of Open Access Journals (Sweden)

    OLORUNFEMI, O.D

    2014-06-01

    Full Text Available This paper examines the sources used by resource poor maize farmers in search of agricultural information on Striga control methods in Kwara State, Nigeria. A well structured interview schedule was used to elicit information using random sampling technique from one hundred and sixty (160 maize farmers in Edu and Patigi Local Government Areas which are highly endemic to Striga infestation in the State. Four sources of information were found effective in disseminating and diffusing Striga control methods in the area which include neighbours and friends, government agencies (ADP, agricultural extension agents and farmers groups. Logistic regression model of determinants of poverty revealed that characteristics of households that were more likely to be impoverished include small household size; low farm income, few years of farming experience and those whom Striga have been on their farms for long thereby having high yield loss to Striga. The study recommends an urgent need for extension agencies to intensify the use of the effective sources of information for disseminating Striga control methods to the farmers and it highlighted policies to improve the livelihoods of the resource-poor maize farmers in the Striga affected areas of Kwara State, Nigeria.

  12. Films, Buckypapers and Fibers from Clay, Chitosan and Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Marc in het Panhuis

    2011-04-01

    Full Text Available The mechanical and electrical characteristics of films, buckypapers and fiber materials from combinations of clay, carbon nanotubes (CNTs and chitosan are described. The rheological time-dependent characteristics of clay are maintained in clay–carbon nanotube–chitosan composite dispersions. It is demonstrated that the addition of chitosan improves their mechanical characteristics, but decreases electrical conductivity by three-orders of magnitude compared to clay–CNT materials. We show that the electrical response upon exposure to humid atmosphere is influenced by clay-chitosan interactions, i.e., the resistance of clay–CNT materials decreases, whereas that of clay–CNT–chitosan increases.

  13. Chitosan-based adsorption and freeze deproteinization: Improved extraction and purification of synthetic colorants from protein-rich food samples.

    Science.gov (United States)

    Kong, Cong; Fodjo, Essy Kouadio; Li, Dan; Cai, Youqiong; Huang, Dongmei; Wang, Yuan; Shen, Xiaosheng

    2015-12-01

    A freeze method for deproteinization coupling with the chitosan purification process was developed for the determination of 8 synthetic food colorants in protein-rich samples. The solvents for extraction and different methods for deproteinization were examined and selected. Chitosan was employed for the purification after deproteinization, and further compared with the traditional polyamine purification method. Determination of the purified extract was conducted through the separation using high performance liquid chromatography and detection by multi-wavelength mode. Under the optimum conditions, the method showed good linearity between 0.6 and 10mg/kg, for the 8 synthetic colorants, and the limit of detection was between 0.1 and 0.4 mg/kg as was defined when the ratio of signal to noise was three. The recoveries of the spiked samples were found to be between 83% and 91%. The intra-day precision and inter-day precision was estimated to be 3-10% and 6-12%, respectively. The developed method could be applied to deproteinization and clean-up for pretreatment of protein-rich samples. PMID:26041188

  14. N-trimethyl chitosan (TMC)-modified microemulsions for improved oral bioavailability of puerarin: preparation and evaluation.

    Science.gov (United States)

    Liao, Dehua; Liu, Xinyi; Dai, Wei; Tang, Tiantian; Ou, Ge; Zhang, Kai; Han, Meng; Kang, Rongrong; Yang, Sufang; Xiang, Daxiong

    2015-01-01

    The aim of this research was to increase the oral bioavailability of puerarin by N-trimethyl chitosan-modified microemulsions (TMC-MEs) loaded with puerarin. Different concentrations of TMC-modified microemulsions were prepared in our study, and then evaluated for particle size, zeta potential, morphological observation and changes of the microenvironment polarity of inner oil core. It was shown that the zeta potential of the microemulsion was increased with the increasing concentration of TMC, and the peak value was achieved when the concentration of TMC was 3.0 mg/mL. The enhancement of the ratio of I(1)/I(3) (the ratio between the first band and the third band of the emission fluorescence spectrum of pyrene, I(1) = 373 nm, I(3) = 384 nm) indicated that polarity of the inner core of TMC-MEs was increased with the addition of the modifier. Pharmacokinetic studies demonstrated that after oral administration of puerarin N-trimethyl chitosan (TMC)-modified microemulsions (PUE-TMEs) and puerarin microemulsions (PUE-MEs) to rats at a dose of 100 mg/kg, relative bioavailability was enhanced about 6.8- and 1.2-fold, respectively, compared to puerarin suspension (PUE-SUS) as control. It indicated that the TMC-MEs could be used as an effective formulation for enhancing the oral bioavailability of puerarin. PMID:24467620

  15. Suppression of Zn stress on barley by irradiated chitosan

    International Nuclear Information System (INIS)

    Chitosan was irradiated up to 1000 kGy in solid state. Irradiation of chitosan caused the reduction of molecular weight. The molecular weight of the chitosan reduced from ca. 4 x 105 to ca. 6 x 103 by irradiation at 1000 kGy. For the barley growth promotion, irradiated chitosan showed the significant effect and 1000 kGy irradiated chitosan improved 20% of growth. Using the positron emitting tracer imaging system (PETIS), the effect of chitosan on uptake and transportation of 62Zn in barley were investigated. It was found that the transportation of Zn from root to shoot and the damage of plant by Zn were suppressed with irradiated chitosan. (author)

  16. Suppression of Zn stress on barley by irradiated chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Nagasawa, N.; Mitomo, H. [Gunma Univ., Faculty of Engineering, Department of Biological and Chemical Engineering, Kiryu, Gunma (Japan); Ha, P.T.L. [Nuclear Research Institute, Dalat (Viet Nam); Watanabe, S.; Ito, T.; Takeshita, H.; Yoshii, F.; Kume, T. [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2001-03-01

    Chitosan was irradiated up to 1000 kGy in solid state. Irradiation of chitosan caused the reduction of molecular weight. The molecular weight of the chitosan reduced from ca. 4 x 10{sup 5} to ca. 6 x 10{sup 3} by irradiation at 1000 kGy. For the barley growth promotion, irradiated chitosan showed the significant effect and 1000 kGy irradiated chitosan improved 20% of growth. Using the positron emitting tracer imaging system (PETIS), the effect of chitosan on uptake and transportation of {sup 62}Zn in barley were investigated. It was found that the transportation of Zn from root to shoot and the damage of plant by Zn were suppressed with irradiated chitosan. (author)

  17. Nanoparticle mediated P-glycoprotein silencing for improved drug delivery across the blood-brain barrier: a siRNA-chitosan approach.

    Directory of Open Access Journals (Sweden)

    Jostein Malmo

    Full Text Available The blood-brain barrier (BBB, composed of tightly organized endothelial cells, limits the availability of drugs to therapeutic targets in the central nervous system. The barrier is maintained by membrane bound efflux pumps efficiently transporting specific xenobiotics back into the blood. The efflux pump P-glycoprotein (P-gp, expressed at high levels in brain endothelial cells, has several drug substrates. Consequently, siRNA mediated silencing of the P-gp gene is one possible strategy how to improve the delivery of drugs to the brain. Herein, we investigated the potential of siRNA-chitosan nanoparticles in silencing P-gp in a BBB model. We show that the transfection of rat brain endothelial cells mediated effective knockdown of P-gp with subsequent decrease in P-gp substrate efflux. This resulted in increased cellular delivery and efficacy of the model drug doxorubicin.

  18. Chitosan in Mucoadhesive Drug Delivery: Focus on Local Vaginal Therapy

    Directory of Open Access Journals (Sweden)

    Toril Andersen

    2015-01-01

    Full Text Available Mucoadhesive drug therapy destined for localized drug treatment is gaining increasing importance in today’s drug development. Chitosan, due to its known biodegradability, bioadhesiveness and excellent safety profile offers means to improve mucosal drug therapy. We have used chitosan as mucoadhesive polymer to develop liposomes able to ensure prolonged residence time at vaginal site. Two types of mucoadhesive liposomes, namely the chitosan-coated liposomes and chitosan-containing liposomes, where chitosan is both embedded and surface-available, were made of soy phosphatidylcholine with entrapped fluorescence markers of two molecular weights, FITC-dextran 4000 and 20,000, respectively. Both liposomal types were characterized for their size distribution, zeta potential, entrapment efficiency and the in vitro release profile, and compared to plain liposomes. The proof of chitosan being both surface-available as well as embedded into the liposomes in the chitosan-containing liposomes was found. The capability of the surface-available chitosan to interact with the model porcine mucin was confirmed for both chitosan-containing and chitosan-coated liposomes implying potential mucoadhesive behavior. Chitosan-containing liposomes were shown to be superior in respect to the simplicity of preparation, FITC-dextran load, mucoadhesiveness and in vitro release and are expected to ensure prolonged residence time on the vaginal mucosa providing localized sustained release of entrapped model substances.

  19. Improving Spring Maize Yield Estimation at Field Scale by Assimilating Time-Series HJ-1 CCD Data into the WOFOST Model Using a New Method with Fast Algorithms

    Directory of Open Access Journals (Sweden)

    Zhiqiang Cheng

    2016-04-01

    Full Text Available Field crop yield prediction is crucial to grain storage, agricultural field management, and national agricultural decision-making. Currently, crop models are widely used for crop yield prediction. However, they are hampered by the uncertainty or similarity of input parameters when extrapolated to field scale. Data assimilation methods that combine crop models and remote sensing are the most effective methods for field yield estimation. In this study, the World Food Studies (WOFOST model is used to simulate the growing process of spring maize. Common assimilation methods face some difficulties due to the scarce, constant, or similar nature of the input parameters. For example, yield spatial heterogeneity simulation, coexistence of common assimilation methods and the nutrient module, and time cost are relatively important limiting factors. To address the yield simulation problems at field scale, a simple yet effective method with fast algorithms is presented for assimilating the time-series HJ-1 A/B data into the WOFOST model in order to improve the spring maize yield simulation. First, the WOFOST model is calibrated and validated to obtain the precise mean yield. Second, the time-series leaf area index (LAI is calculated from the HJ data using an empirical regression model. Third, some fast algorithms are developed to complete assimilation. Finally, several experiments are conducted in a large farmland (Hongxing to evaluate the yield simulation results. In general, the results indicate that the proposed method reliably improves spring maize yield estimation in terms of spatial heterogeneity simulation ability and prediction accuracy without affecting the simulation efficiency.

  20. Improvement of intestinal absorption of forsythoside A and chlorogenic acid by different carboxymethyl chitosan and chito-oligosaccharide, application to Flos Lonicerae-Fructus Forsythiae herb couple preparations.

    Directory of Open Access Journals (Sweden)

    Wei Zhou

    Full Text Available The current study aims to investigate the effect of chitosan derivatives on the intestinal absorption and bioavailabilities of forsythoside A (FTA and Chlorogenic acid (CHA, the major active components in Flos Lonicerae-Fructus Forsythiae herb couple. Biopharmaceutics and pharmacokinetics properties of the two compounds have been characterized in vitro, in situ as well as in rats. Based on the identified biopharmaceutics characteristics of the two compounds, the effect of chitosan derivatives as an absorption enhancer on the intestinal absorption and pharmacokinetics of FTA and CHA in pure compound form as well as extract form were investigated in vitro, in situ and in vivo. Both FTA and CHA demonstrated very limited intestinal permeabilities, leading to oral bioavailabilities being only 0.50% and 0.13% in rats, respectively. Results from both in vitro, in situ as well as in vivo studies consistently indicated that Chito-oligosaccharide (COS at dosage of 25 mg/kg could enhance intestinal permeabilities significantly as well as the in vivo bioavailabilities of both FTA and CHA than CMCs in Flos Lonicerae-Fructus Forsythiae herb couple preparations, and was safe for gastrointestine from morphological observation. Besides, treatment with Flos Lonicerae-Fructus Forsythiae herb couple preparations with COS at the dosage of 25 mg/kg prevented MDCK damage after influenza virus propagation, which was significantly better than control. The current findings not only identified the usefulness of COS for the improved delivery of Flos Lonicerae-Fructus Forsythiae preparations but also demonstrated the importance of biopharmaceutical characterization in the dosage form development of traditional Chinese medicine.

  1. In-Season Root-Zone Nitrogen Management Strategies for Improving Nitrogen Use Efficiency in High-Yielding Maize Production in China

    Institute of Scientific and Technical Information of China (English)

    MENG Qing-Feng; CHEN Xin-Ping; ZHANG Fu-Suo; CAO Ming-Hui; CUI Zhen-Ling; BAI Jin-Shun; YUE Shan-Chao; CHEN Su-Yi; T.M(U)LLER

    2012-01-01

    Many recently developed N management strategies have been extremely successful in improving N use efficiency.However,attempts to further increase grain yields have had limited success.Field experiments were conducted in 2007 and 2008 at four sites to evaluate the effect of an in-season root-zone N management strategy on maize (Zea mays L.).According to the in-season root-zone N management,the optimal N rate (ONR) was determined by subtracting measured soil mineral N (NH4+-N and NO3--N) in the root zone from N target values.Other treatments included a control without N fertilization,70% of ONR,130% of ONR,and recommended N rate (RNR) by agronomists in China that have been shown to approach maize yield potentials.Although apparent N recovery for the ONR treatment was significantly higher than that under RNR in 2007,grain yield declined from 13.3 to 11.0 Mg ha-1 because of an underestimation of N uptake.In 2008,N target values were adjusted to match crop uptake,and N fertilization rates were reduced from 450 kg N ha- 1 for RNR to 225 to 265 kg N ha-1 for ONR.High maize yields were maintained at 12.6 to 13.5 Mg ha-1,which were twice the yield from typical farmers'practice.As a result,apparent N recovery increased from 29% to 66%,and estimated N losses decreased significantly for the ONR treatment compared to the RNR treatment.In conclusion,the in-season root-zone N management approach was able to achieve high yields,high NUE and low N losses.

  2. Environmental applications of chitosan and its derivatives.

    Science.gov (United States)

    Yong, Soon Kong; Shrivastava, Manoj; Srivastava, Prashant; Kunhikrishnan, Anitha; Bolan, Nanthi

    2015-01-01

    Chitosan originates from the seafood processing industry and is one of the most abundant of bio-waste materials. Chitosan is a by-product of the alkaline deacetylation process of chitin. Chemically, chitosan is a polysaccharide that is soluble in acidic solution and precipitates at higher pHs. It has great potential for certain environmental applications, such as remediation of organic and inorganic contaminants, including toxic metals and dyes in soil, sediment and water, and development of contaminant sensors. Traditionally, seafood waste has been the primary source of chitin. More recently, alternative sources have emerged such as fungal mycelium, mushroom and krill wastes, and these new sources of chitin and chitosan may overcome seasonal supply limitations that have existed. The production of chitosan from the above-mentioned waste streams not only reduces waste volume, but alleviates pressure on landfills to which the waste would otherwise go. Chitosan production involves four major steps, viz., deproteination, demineralization, bleaching and deacetylation. These four processes require excessive usage of strong alkali at different stages, and drives chitosan's production cost up, potentially making the application of high-grade chitosan for commercial remediation untenable. Alternate chitosan processing techniques, such as microbial or enzymatic processes, may become more cost-effective due to lower energy consumption and waste generation. Chitosan has proved to be versatile for so many environmental applications, because it possesses certain key functional groups, including - OH and -NH2 . However, the efficacy of chitosan is diminished at low pH because of its increased solubility and instability. These deficiencies can be overcome by modifying chitosan's structure via crosslinking. Such modification not only enhances the structural stability of chitosan under low pH conditions, but also improves its physicochemical characteristics, such as porosity

  3. Biotechnology in maize breeding

    Directory of Open Access Journals (Sweden)

    Mladenović-Drinić Snežana

    2004-01-01

    Full Text Available Maize is one of the most important economic crops and the best studied and most tractable genetic system among monocots. The development of biotechnology has led to a great increase in our knowledge of maize genetics and understanding of the structure and behaviour of maize genomes. Conventional breeding practices can now be complemented by a number of new and powerful techniques. Some of these often referred to as molecular methods, enable scientists to see the layout of the entire genome of any organism and to select plants with preferred characteristics by "reading" at the molecular level, saving precious time and resources. DNA markers have provided valuable tools in various analyses ranging from phylogenetic analysis to the positional cloning of genes. Application of molecular markers for genetic studies of maize include: assessment of genetic variability and characterization of germ plasm, identification and fingerprinting of genotypes, estimation of genetic distance, detection of monogamic and quantitative trait loci, marker assisted selection, identification of sequence of useful candidate genes, etc. The development of high-density molecular maps which has been facilitated by PCR-based markers, have made the mapping and tagging of almost any trait possible and serve as bases for marker assisted selection. Sequencing of maize genomes would help to elucidate gene function, gene regulation and their expression. Modern biotechnology also includes an array of tools for introducing or deieting a particular gene or genes to produce plants with novel traits. Development of informatics and biotechnology are resulted in bioinformatic as well as in expansion of microarrey technique. Modern biotechnologies could complement and improve the efficiency of traditional selection and breeding techniques to enhance agricultural productivity.

  4. Application of bokashi and sunn hemp (Crotalaria juncea L. to improve inorganic fertilizer efficiency on maize (Zea mays L.

    Directory of Open Access Journals (Sweden)

    A.I. Yuliana

    2015-10-01

    Full Text Available A field experiment was conducted lo learn about the effect of Bokashi and Sunn hemp (Crotalaria juncea L. on maize production and inorganic fertilizer use efficiency on maize. The experiment was conducted in Jatikerto, Malang; at the altitude of 303 m above sea level, in Alfisol soil type, the average daily temperature ranges 21-33oC, from June to October 2013. The experiment was conducted as factorial, designed in a randomized block design (RBD. The first factor was dose of inorganic fertilizer (100% ; 75% and 50% of recommendation dose. The second factor was the organic fertilizer (Without organic fertilizer20 t Bokashi/ ha, 20 t Sunn hemp/ha, 10 t Bokashi/ha + 10 t Sunn hemp/ha. The results showed that application of 20 t Bokashi/ha, 20 t Sunn hemp/ha, and combination of 10 t Bokashi/ha + 10 t Sunn hemp/ha, along with the application of inorganic fertilizer by dose of 100% increased the yields of maize for about 41.8%; 47.6% and 54.7% (10.73 t/ha; 11.17 t/ha, and 11.71 t/ha, respectively. The yield and nutrient use efficiency in the treatment dose of 100% inorganic fertilizer did not have any significant difference from the application of 20 t Bokashi /ha, 20 t Sunn hemp/ha, and 10 t Bokashi/ha + 10 t Sunn hemp/ha along with doses of inorganic fertilization 75% and 50%. Therefore, the organic fertilizer of 20 t Bokashi/ ha, 20 t Sunn hemp/ha, and combination of 10 t Bokashi/ha + 10 t Sunn hemp/ha could reduce the need of inorganic fertilizer for about 50%.

  5. Films, Buckypapers and Fibers from Clay, Chitosan and Carbon Nanotubes

    OpenAIRE

    Marc in het Panhuis; Holly Warren; Higgins, Thomas M.

    2011-01-01

    The mechanical and electrical characteristics of films, buckypapers and fiber materials from combinations of clay, carbon nanotubes (CNTs) and chitosan are described. The rheological time-dependent characteristics of clay are maintained in clay–carbon nanotube–chitosan composite dispersions. It is demonstrated that the addition of chitosan improves their mechanical characteristics, but decreases electrical conductivity by three-orders of magnitude compared to clay–CNT materials. We show that ...

  6. Quantum dot/glycol chitosan fluorescent nanoconjugates

    OpenAIRE

    Mansur, Alexandra AP; Mansur, Herman S.

    2015-01-01

    In this study, novel carbohydrate-based nanoconjugates combining chemically modified chitosan with semiconductor quantum dots (QDs) were designed and synthesised via single-step aqueous route at room temperature. Glycol chitosan (G-CHI) was used as the capping ligand aiming to improve the water solubility of the nanoconjugates to produce stable and biocompatible colloidal systems. UV-visible (UV–vis) spectroscopy, photoluminescence (PL) spectroscopy, and Fourier transform infrared (FTIR) spec...

  7. Formulation of insulin-loaded N-trimethyl chitosan microparticles with improved efficacy for inhalation by supercritical fluid assisted atomization.

    Science.gov (United States)

    Shen, Yu-Bin; Du, Zhe; Tang, Chuan; Guan, Yi-Xin; Yao, Shan-Jing

    2016-05-30

    Supercritical fluid assisted atomization introduced by a hydrodynamic cavitation mixer (SAA-HCM) was proposed as a green technique to fabricate insulin-loaded dry powders for inhalation administration. N-trimethyl chitosan (TMC), a polymeric mucoadhesive absorption enhancer, was synthesized and successfully micronized from aqueous solution using SAA-HCM. The prepared well-defined spherical TMC microparticles with preserved structure and thermal stability were potential carriers for delivery of proteins. Then, insulin-loaded TMC microparticles with high loading efficiency were coprecipitated from aqueous solutions using SAA-HCM without use of any organic solvents. The polymer/protein ratio revealed to be a factor influencing the particle morphology, and non-coalescing composite microparticles in amorphous state mainly ranging from 1μm to 5μm could be obtained in this work. Aerodynamic properties were assessed by next generation impactor (NGI) and the mass median aerodynamic diameter (MMAD) lied inside the inhalable range of 1-5μm, while fine particle fraction (FPF) reached above 60%. The structural integrity of encapsulated insulin was confirmed by HPLC, circular dichroism and fluorescence spectroscopy. In vivo study demonstrated that TMC could enhance the absorption and bioavailability of the pulmonarily administered insulin formulation for SD rats. These results suggest that TMC microparticles could be efficiently prepared as a promising vehicle for drug delivery, and SAA-HCM is a promising technique to prepare inhalable polymer/protein composite dry powders. PMID:27034000

  8. New antimicrobial chitosan derivatives for wound dressing applications.

    Science.gov (United States)

    Dragostin, Oana Maria; Samal, Sangram Keshari; Dash, Mamoni; Lupascu, Florentina; Pânzariu, Andreea; Tuchilus, Cristina; Ghetu, Nicolae; Danciu, Mihai; Dubruel, Peter; Pieptu, Dragos; Vasile, Cornelia; Tatia, Rodica; Profire, Lenuta

    2016-05-01

    Chitosan is a non-toxic, biocompatible, biodegradable natural cationic polymer known for its low imunogenicity, antimicrobial, antioxidant effects and wound-healing activity. To improve its therapeutic potential, new chitosan-sulfonamide derivatives have been designed to develop new wound dressing biomaterials. The structural, morphological and physico-chemical properties of synthesized chitosan derivatives were analyzed by FT-IR, (1)H NMR spectroscopy, scanning electron microscopy, swelling ability and porosity. Antimicrobial, in vivo testing and biodegradation behavior have been also performed. The chitosan derivative membranes showed improved swelling and biodegradation rate, which are important characteristics required for the wound healing process. The antimicrobial assay evidenced that chitosan-based sulfadiazine, sulfadimethoxine and sulfamethoxazole derivatives were the most active. The MTT assay showed that some of chitosan derivatives are nontoxic. Furthermore, the in vivo study on burn wound model induced in Wistar rats demonstrated an improved healing effect and enhanced epithelialization of chitosan-sulfonamide derivatives compared to neat chitosan. The obtained results strongly recommend the use of some of the newly developed chitosan derivatives as antimicrobial wound dressing biomaterials. PMID:26876993

  9. Aqueous Behaviour of Chitosan

    Directory of Open Access Journals (Sweden)

    D. P. Chattopadhyay

    2010-01-01

    Full Text Available Chitosan, a versatile biopolymer, finds numerous applications in textile processing unit operations such as preparation, dyeing, printing, and finishing. However, the accessibility of this biopolymer by the textile material depends on the viscosity of its solution which in turn is a function of its molecular weight. In this work, therefore, the effect of molecular weight, storage life, presence of electrolyte, and particle size of chitosan on its viscosity was investigated. Chitosan of different molecular weights was synthesized by nitrous acid hydrolysis of parent chitosan solution. The synthesized low molecular weight products were analysed by FTIR spectroscopy. Chitosan of nanoconfiguration was prepared by Ionotropic gelation method and characterized by particle size analyzer. The viscosity of different chitosan solutions was determined using Ubbelohde capillary viscometer. As an extension to this study, the chelation property of chitosan was also evaluated.

  10. Chitosan and radiation chemistry

    Science.gov (United States)

    Chmielewski, Andrzej G.

    2010-03-01

    Chitosan as a raw material with special properties has drawn attention of scientists working in the field of radiation processing and natural polymer products development, and also of specialists working in the field of radiation protection and oncologists. Especially the applications concern reduced molecular weight chitosan which still retain its chemical structure; such form of the compound is fostering biological, physical and chemical reactivity of the product. Chitosan degrades into fragments under γ-ray or electron beam irradiation. Antibacterial properties of the product are applied in manufacturing hydrogel for wound dressing and additional healing properties can be achieved by incorporating in the hydrogel matrix chitosan bonded silver clusters. Another possible application of chitosan is in reducing radiation damage to the radiation workers or radiation cured patients. In the case of radioisotopes oral or respiratory chitosan-based materials can be applied as chelators. Applications of chitosan in oncology are also reported.

  11. Chitosan and radiation chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Chmielewski, Andrzej G., E-mail: a.chmielewski@ichtj.waw.p [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    2010-03-15

    Chitosan as a raw material with special properties has drawn attention of scientists working in the field of radiation processing and natural polymer products development, and also of specialists working in the field of radiation protection and oncologists. Especially the applications concern reduced molecular weight chitosan which still retain its chemical structure; such form of the compound is fostering biological, physical and chemical reactivity of the product. Chitosan degrades into fragments under gamma-ray or electron beam irradiation. Antibacterial properties of the product are applied in manufacturing hydrogel for wound dressing and additional healing properties can be achieved by incorporating in the hydrogel matrix chitosan bonded silver clusters. Another possible application of chitosan is in reducing radiation damage to the radiation workers or radiation cured patients. In the case of radioisotopes oral or respiratory chitosan-based materials can be applied as chelators. Applications of chitosan in oncology are also reported.

  12. Chitosan and radiation chemistry

    International Nuclear Information System (INIS)

    Chitosan as a raw material with special properties has drawn attention of scientists working in the field of radiation processing and natural polymer products development, and also of specialists working in the field of radiation protection and oncologists. Especially the applications concern reduced molecular weight chitosan which still retain its chemical structure; such form of the compound is fostering biological, physical and chemical reactivity of the product. Chitosan degrades into fragments under γ-ray or electron beam irradiation. Antibacterial properties of the product are applied in manufacturing hydrogel for wound dressing and additional healing properties can be achieved by incorporating in the hydrogel matrix chitosan bonded silver clusters. Another possible application of chitosan is in reducing radiation damage to the radiation workers or radiation cured patients. In the case of radioisotopes oral or respiratory chitosan-based materials can be applied as chelators. Applications of chitosan in oncology are also reported.

  13. Recent advances in chitosan-based nanoparticulate pulmonary drug delivery.

    Science.gov (United States)

    Islam, Nazrul; Ferro, Vito

    2016-08-14

    The advent of biodegradable polymer-encapsulated drug nanoparticles has made the pulmonary route of administration an exciting area of drug delivery research. Chitosan, a natural biodegradable and biocompatible polysaccharide has received enormous attention as a carrier for drug delivery. Recently, nanoparticles of chitosan (CS) and its synthetic derivatives have been investigated for the encapsulation and delivery of many drugs with improved targeting and controlled release. Herein, recent advances in the preparation and use of micro-/nanoparticles of chitosan and its derivatives for pulmonary delivery of various therapeutic agents (drugs, genes, vaccines) are reviewed. Although chitosan has wide applications in terms of formulations and routes of drug delivery, this review is focused on pulmonary delivery of drug-encapsulated nanoparticles of chitosan and its derivatives. In addition, the controversial toxicological effects of chitosan nanoparticles for lung delivery will also be discussed. PMID:27439116

  14. Research of the Mechanism of Enhancing Biological Treatment by Chitosan

    Institute of Scientific and Technical Information of China (English)

    CHEN Liang; QIN Bing; CHEN Dong-hui

    2006-01-01

    Chitosan of different molecular weight (M. W. ) was added into SBR bioreactor to treat domestic wastewater. From comparison of treatment efficiency, sludge activity, sludge structure etc., we revealed the mechanism that chitosan enhanced the biological treatment function of activated sludge. The results proved that, chitosan is certain to restrain the reaction of activated sludge, but it do improve the structure of sludge fiocs and increase the treatment efficiency of activated sludge. The bigger the M. W. of chitosan is, the better the efficiency of enhancing biological treatment can be.

  15. Synthesis of Conjugated Chitosan and its Effect on Drug Permeation from Transdermal Patches

    OpenAIRE

    B K Satheeshababu; K L Shivakumar

    2013-01-01

    The aim of this study was to synthesis the conjugated chitosan by covalent attachment of thiol moieties to the cationic polymer, mediated by a carbodiimide to improve permeation properties of chitosan. Thioglycolic acid was covalently attached to chitosan by the formation of amide bonds between the primary amino groups of the polymer and the carboxylic acid groups of thioglycolic acid. Hence, these polymers are called as thiomers or thiolated polymers. Conjugation of chitosan was confirmed by...

  16. Processing and characterization of 3D dense chitosan pieces, for orthopedic applications, by adding plasticizers

    OpenAIRE

    Figueiredo, Lígia; Moura, Carla; Pinto, Luís F. V.; Ferreira, Frederico Castelo; Rodrigues, Alexandra

    2015-01-01

    In this work, plasticizer agents were incorporated in a chitosan based formulation, as a strategy to improve the fragile structure of chitosan based-materials. Three different plasticizers: ethylene glycol, glycerol and sorbitol, were blended with chitosan to prepare 3D dense chitosan specimens. The properties of the obtained structures were assessed for mechanical, microstructural, physical and biocompatibility behavior. The results obtained revealed that from the different specimens prepare...

  17. Improvement of Intestinal Absorption of Forsythoside A and Chlorogenic Acid by Different Carboxymethyl Chitosan and Chito-oligosaccharide, Application to Flos Lonicerae - Fructus Forsythiae Herb Couple Preparations

    OpenAIRE

    Wei Zhou; Haidan Wang; Xuanxuan Zhu; Jinjun Shan; Ailing Yin; Baochang Cai; Liuqing Di

    2013-01-01

    The current study aims to investigate the effect of chitosan derivatives on the intestinal absorption and bioavailabilities of forsythoside A (FTA) and Chlorogenic acid (CHA), the major active components in Flos Lonicerae - Fructus Forsythiae herb couple. Biopharmaceutics and pharmacokinetics properties of the two compounds have been characterized in vitro, in situ as well as in rats. Based on the identified biopharmaceutics characteristics of the two compounds, the effect of chitosan derivat...

  18. Chitosan-tripolyphosphate nanoparticles: Optimization of formulation parameters for improving process yield at a novel pH using artificial neural networks.

    Science.gov (United States)

    Hashad, Rania A; Ishak, Rania A H; Fahmy, Sherif; Mansour, Samar; Geneidi, Ahmed S

    2016-05-01

    At a novel pH value of the polymeric solution (6.2), variable chitosan (Cs) and sodium tripolyphosphate (TPP) concentrations and mass ratios were optimized to improve the process yield without undesirable particle flocculation. Prepared formulations were characterized in terms of particle size (PS), zeta potential (ZP) and percentage yield (% yield). Artificial neural networks (ANN) were built up and used to identify the parameters that control nanoparticle (NP) size and yield, in addition to being tested for their ability to predict these two experimental outputs. Using these networks, it was found that TPP concentration has the greatest effect on PS and% yield. The most optimum formulation was characterized by a notable process yield reaching 91.5%, a mean hydrodynamic PS 227 nm, ZP+24.13 mv and spherical compact morphology. Successful Cs-TPP interaction in NP formation was confirmed by both Fourier transform-infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). This study demonstrated the ability of ANN to predict not only PS of the formed particles but also NP% yield. This may have a great impact on Cs-TPP NPs preparation and can be used to customize the required target formulations. PMID:26783636

  19. Glassy carbon electrode modified with gold nanoparticles and hemoglobin in a chitosan matrix for improved pH-switchable sensing of hydrogen peroxide

    International Nuclear Information System (INIS)

    Hemoglobin (Hb) has been demonstrated to endow electrochemical sensors with pH-switchable response because of the presence of carboxyl and amino groups. Hb was deposited in a chitosan matrix on a glassy carbon electrode (GCE) that was previously coated with clustered gold nanoparticles (Au-NPs) by electrodeposition. The switching behavior is active (“on”) to the negatively charged probe [Fe(CN)63−] at pH 4.0, but inactive (“off”) to the probe at pH 8.0. This switch is fully reversible by simply changing the pH value of the solution and can be applied for pH-controlled reversible electrochemical reduction of H2O2 catalyzed by Hb. The modified electrode was tested for its response to the different electroactive probes. The response to these species strongly depends on pH which was cycled between 4 and 8. The effect is also attributed to the presence of pH dependent charges on the surface of the electrode which resulted in either electrostatic attraction or repulsion of the electroactive probes. The presence of Hb, in turn, enhances the pH-controllable response, and the electrodeposited Au-NPs improve the capability of switching. This study reveals the potential of protein based pH-switchable materials and also provides a simple and effective strategy for fabrication of switchable chemical sensors as exemplified in a pH-controllable electrode for hydrogen peroxide. (author)

  20. Chitosan blended bacterial cellulose as a smart material for biomedical application

    Science.gov (United States)

    Cai, Zhijiang; Jin, Hyoung-Joon; Kim, Jaehwan

    2009-03-01

    Bacterial cellulose and chitosan blends have been successfully prepared by immersing wet bacterial cellulose pellicle in chitosan solution followed by freeze-drying. By changing chitosan concentration and immersion time, the chitosan content in the blends is ranged from 12% to 45%. The products look like a foam structure. SEM images show that chitosan molecules can penetrate into bacterial cellulose forming multilayer structure. The foam has very well interconnected porous network structure and large aspect surface. By incorporation of chitosan in bacterial cellulose, XRD patterns indicate that crystalline structure does not change but crystallinity decreases from 82% to 61% with chitosan content increasing from 12% to 45%. According to TGA results, the thermal stability has been improved. At the same time, the mechanical properties of bacterial cellulose and chitosan blends are good enough for potential biomedical application such as tissue engineering scaffold and would dressing material.

  1. Romanian maize

    DEFF Research Database (Denmark)

    Sauer, Johannes; Balint, Borbala

    This research aims at shedding empirical light on the relative efficiency of small-scale maize producers in Romania. Farmers in transition countries still face heavily distorted price systems resulting from imperfect market conditions and socioeconomic and institutional constraints. To capture such...... models are estimated due to the imposition of curvature correctness and the effects on the individual efficiency estimates are shown. The empirical results show a relative high technical efficiency of the small-scale farmers but relatively poor scores on systematic input price efficiency. The usage of...

  2. Biophysical studies on chitosan-coated liposomes.

    Science.gov (United States)

    Mady, Mohsen M; Darwish, Mirhane M; Khalil, Safaa; Khalil, Wafaa M

    2009-10-01

    Liposomes have been used as delivery vehicles for stabilizing drugs, overcoming barriers to cellular and tissue uptake, and for directing their contents toward specific sites in vivo. Chitosan is a biological macromolecule derived from crustacean shells and has several emerging applications in drug development, obesity control, and tissue engineering. In the present work, the interaction between chitosan and dipalmitoyl phosphatidylcholine (DPPC) liposomes was studied by transmission electron microscopy (TEM), zeta potential, solubilization using the nonionic detergent octylglucoside (OG), as well as Fourier transform infrared (FTIR) spectroscopy and viscosity measurements. The coating of DPPC liposomes by a chitosan layer was confirmed by electron microscope images and the zeta potential of liposomes. Coating of liposome by chitosan resulted in an increase in liposomal size by addition of a layer of 92 +/- 27.1 nm. The liposomal zeta potential became increasingly positive as chitosan concentration increased from 0.1 to 0.3% w/v, then it held at a relatively constant value. The amount of detergent needed to completely solubilize the liposomal membrane was increased after coating of liposomes with chitosan, indicating an increased membrane resistance to the detergent and hence a change in the natural membrane permeation properties. In the analysis of FTIR spectra of DPPC, the symmetric and antisymmetric CH(2) (at 2,800-3,000 cm(-1)) bands and the C=O (at 1,740 cm(-1)) stretching band were investigated in the absence and presence of the chitosan. It was concluded that appropriate combining of the liposomal and chitosan characteristics might be utilized for the improvement of the therapeutic efficacy of liposomes as a drug delivery system. PMID:19649627

  3. Chitosan grafted monomethyl fumaric acid as a potential food preservative.

    Science.gov (United States)

    Khan, Imran; Ullah, Shafi; Oh, Deog-Hwan

    2016-11-01

    The present study aims at in vitro antibacterial and antioxidant activity evaluation of chitosan modified with monomethyl fumaric acid (MFA) using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) as mediator. Three different kinds of chitosan derivatives Ch-Ds-1,Ch-Ds-2 and Ch-Ds-3 were synthesized by feeding different concentration of MFA. The chemical structures of resulting materials were characterized by (1)H NMR, (13)C NMR, HR-XRD, FT-IR and TNBS assay. The results showed that Ch-Ds-1, Ch-Ds-2 and Ch-Ds-3 were successfully synthesized. The % amino groups of chitosan modified by MFA were evaluated by TNBS assay and ranging from 1.82±0.05% to 7.88±0.04%. All the chitosan derivatives are readily soluble in water and swelled by dimethyl sulfoxide (DMSO), toluene and dimethyl formamide (DMF). The antioxidant activity for all the chitosan derivatives have been significantly improved (P<0.05) compared to the chitosan. Upon antibacterial activity at pH 4.0, all the chitosan derivatives showed significant (P<0.05) antibacterial activity against Gram positive Staphylococcus aureus, Listeria monocytogenes strains and Gram negative Escherichia coli and Salmonella enteritidis strains compared to chitosan. In conclusion, MFA modified chitosan has shown enhanced activities along with solubility, and could be used as a novel food preservative and packaging material for long time food safety and security. PMID:27516253

  4. Effect of Spatial Arrangement on Growth and Yield of Cowpea in a Cowpea-maize Intercrop

    Directory of Open Access Journals (Sweden)

    Ocaya, CP.

    2001-01-01

    Full Text Available Cowpea growth and yield performance when intercropped with maize was studied for 3 consecutive seasons under three spatial arrangements, i. e., maize planted at 90 x 30, 100 x 27, and 120 x 22.5 cm, with 2 rows of cowpea between the maize rows. Growth and yield of cowpea was improved significantly by widening maize intra-row distances as compared to the 90 x 30 cm spacing. Hence, intercropped cowpea needs to be sown where maize rows are wide apart, but the maize rows should not be too wide as this would lower the grain yield of maize.

  5. Integrated use of biochar: a tool for improving soil and wheat quality of degraded soil under wheat-maize cropping pattern

    International Nuclear Information System (INIS)

    Wheat quality, nutrient uptake and nutrient use efficiency are significantly influenced by nutrient sources and application rate. To investigate the integrative effect of biochar, farmyard manure (FYM) and nitrogen (organic and inorganic soil amendments) in a wheat-maize cropping system, a two year study was designed to assess the interactive outcome of biochar, FYM and nitrogenous fertilizer on wheat nitrogen (N) parameters and associated soil quality parameters. Three levels of biochar (0, 25 and 50 t ha-1), two levels of FYM (5 and 10 t ha-1) and two levels of nitrogen fertilizer (60 and 120 kg ha-1) were used in the study. Biochar application displayed a significantly increased in wheat leaf, stem, straw and grain N content; grain and total N-uptake and grain protein content by 24, 20, 24, 56, 50, 17 and 20% respectively. Similarly, biochar application significantly increased soil total N (TN) and soil mineral N (SMN) by 63 and 40% respectively in second year. FYM application increased grain, leaf and straw N content by 20, 19.5 and 18% respectively, and increased total N-uptake and grain protein content by 49 and 19% respectively. FYM increased soil TN and SMN by 63 and 32% in both the years of the experiment. Mineral N application increased soil TN by over a half and SMN by a third, and grain protein content increased 16%. In contrast, nitrogen use efficiency (NUE) decreased for all amendments relative to the control. However, biochar treated plots improved NUE by 38% compared to plots without biochar. In conclusion, this field experiment has illustrated the potential of biochar to bring about short-term benefits in wheat and soil quality parameters in wheat-maize cropping systems. However, the long-term benefits remain to be quantified. (author)

  6. Salt stress in maize: effects, resistance mechanisms, and management. A review

    OpenAIRE

    Farooq, Muhammad; Hussain, Mubshar; Wakeel, Abdul; Kadambot H M Siddique

    2015-01-01

    Maize is grown under a wide spectrum of soil and climatic conditions. Maize is moderately sensitive to salt stress; therefore, soil salinity is a serious threat to its production worldwide. Understanding maize response to salt stress and resistance mechanisms and overviewing management options may help to devise strategies for improved maize performance in saline environments. Here, we reviewed the effects, resistance mechanisms, and management of salt stress in maize. Our main conclusions ar...

  7. Preparation of chitosan gel

    Directory of Open Access Journals (Sweden)

    Lagerge S.

    2012-06-01

    Full Text Available Aerogel conditioning of the chitosan makes it possible to prepare porous solids of significant specific surface. The increase in the chitosan concentration or the degree of acetylation decreases the specific surface of the synthesized chitosan gel. Whereas drying with supercritical CO2 more effectively makes it possible to preserve the volume of the spheres of gel and to have a more significant specific surface in comparison with evaporative drying.

  8. FACTORS INFLUENCING ADOPTION DECISIONS OF MAIZE FARMERS IN NIGERIA

    OpenAIRE

    Olusegun Ayodeji Fadare; Dare Akerele; Begho Toritseju

    2014-01-01

    The needs to develop improved varieties of maize have been in the heart of various researchers and institutions in Nigeria because of its strategic role in tackling food insecurity and poverty. Despite substantial efforts to improve maize varieties, the level of adoption of improved maize varieties (IMV) in Nigeria in still very low. Although previous adoption studies have indicated a number of socioeconomic and institutional/organizational variables as important factors influe...

  9. Preparation, characterization and antibacterial activity of chitosan and phosphorylated chitosan from cuttlebone of Sepia kobiensis (Hoyle, 1885

    Directory of Open Access Journals (Sweden)

    Annaian Shanmugam

    2016-03-01

    Full Text Available Chitosan is a commercially available derivative of chitin that has been extensively studied for its antimicrobial properties. In order to improve the water solubility and its biological activity, the chemical modification or derivatisation is attempted. In the present investigation, the chitosan prepared from the cuttlebone of Sepia kobiensis was being chemically modified by reacting it with orthophosphoric acid so as to obtain phosphorylated chitosan. Then the chitosan and phosphorylated chitosan were structurally characterized through FT-IR spectroscopy. Further the antibacterial activity of chitosan and phosphorylated chitosan was tested against clinically isolated human pathogens (Gram-positive: Streptococcus sp., Streptococcus pneumoniae and Staphylococcus aureus and Gram-negative: Escherichia coli, Vibrio cholerae, V. alginolyticus, Vibrio parahaemolyticus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella sp. and Proteus vulgaris by well diffusion method and the Minimum Inhibitory Concentration (MIC was also calculated. The results of the present study suggests that the chitosan and phosphorylated chitosan has concentration dependent antibacterial activity with variation against several pathogenic human pathogenic bacterial strains which indicates their possible use as antibacterial agents.

  10. Degradation and compatibility behaviors of poly(glycolic acid) grafted chitosan

    International Nuclear Information System (INIS)

    The films of poly(glycolic acid) grafted chitosan were prepared without using a catalyst to improve the degradable property of chitosan. The films were characterized by Fourier transform-infrared spectroscopy and X-ray photoelectron spectroscopy (XPS). The degradation of the poly(glycolic acid) grafted chitosan films were investigated in the lysozyme solution. In vitro degradation tests revealed that the degradation rate of poly(glycolic acid) grafted chitosan films increased dramatically compared with chitosan. The degradation rate of poly(glycolic acid) grafted chitosan films gradually increased with the increasing of the molar ratio of glycolic acid to chitosan. Additionally, the poly(glycolic acid) grafted chitosan films have good biocompatibility, as demonstrated by in vitro cytotoxicity of the extraction fluids. The biocompatible and biodegradable poly(glycolic acid) grafted chitosan would be an effective material with controllable degradation rate to meet the diverse needs in biomedical fields. - Highlights: ► Chitosan-g-poly(glycolic acid) copolymer was prepared without using a catalyst. ► Degradation rate of copolymer increased dramatically compared with that of chitosan. ► Degradation rate was controlled by the molar ratio of glycolic acid to chitosan. ► In vitro cytotoxicity tests revealed that the copolymer has good biocompatibility. ► The copolymer has a great potential to meet diverse needs in biomedical fields

  11. Mechanisms of chitosan-coated poly(lactic-co-glycolic acid) nanoparticles for improving oral absorption of 7-ethyl-10-hydroxycamptothecin

    International Nuclear Information System (INIS)

    Chitosan-modified poly(lactic-co-glycolic acid) nanoparticles (CHI/PLGA NPs) loaded with 7-ethyl-10-hydroxycamptothecin (SN-38), named CHI/PLGA/SN-38 NPs, were successfully prepared using an oil-in-water (O/W) solvent evaporation method. The physicochemical properties of the novel NPs were characterized by DLS, Zeta potential, SEM, DSC, XRD, and FTIR. The encapsulation efficiency and drug loading content were 71.83 (±2.77)% and 6.79 (±0.26)%, respectively. In vitro drug release in the simulated gastric juice was lower than that in the intestinal juice. In situ single-pass intestinal perfusion (SPIP) studies indicated a dramatic improvement of drug absorption as a result of the synergistic effect between CHI and PLGA on P-glycoprotein (Pgp) inhibition. CHI/PLGA NPs showed high cellular uptake and low efflux for drugs in Caco-2 cells. The cytotoxicity studies revealed that CHI/PLGA NPs had a transient effect on the membrane integrity, but did not have an influence on cell viability. Based on the in vitro release studies, SPIP, and intracellular drug accumulation and transport investigations, we speculate rationally that CHI/PLGA NPs were mainly internalized in the form of intact NPs, thus escaping the recognition of enterocyte Pgp and avoiding efflux into the apical part of the enterocytes. After partial release of drugs inside the enterocytes, CHI/PLGA interfered with the microenvironment of Pgp and further weakened the Pgp-mediated efflux. Then, the drug-loaded NPs exited via the exocytose effect from the basal part of the enterocytes and entered the blood circulation. These results showed that CHI/PLGA NPs would be smart oral delivery carriers for antineoplastic agents that are also Pgp substrates. (paper)

  12. Mechanisms of chitosan-coated poly(lactic-co-glycolic acid) nanoparticles for improving oral absorption of 7-ethyl-10-hydroxycamptothecin

    Science.gov (United States)

    Guo, Miao; Rong, Wen-Ting; Hou, Jie; Wang, Dong-Fang; Lu, Yu; Wang, Ying; Yu, Shu-Qin; Xu, Qian

    2013-06-01

    Chitosan-modified poly(lactic-co-glycolic acid) nanoparticles (CHI/PLGA NPs) loaded with 7-ethyl-10-hydroxycamptothecin (SN-38), named CHI/PLGA/SN-38 NPs, were successfully prepared using an oil-in-water (O/W) solvent evaporation method. The physicochemical properties of the novel NPs were characterized by DLS, Zeta potential, SEM, DSC, XRD, and FTIR. The encapsulation efficiency and drug loading content were 71.83 (±2.77)% and 6.79 (±0.26)%, respectively. In vitro drug release in the simulated gastric juice was lower than that in the intestinal juice. In situ single-pass intestinal perfusion (SPIP) studies indicated a dramatic improvement of drug absorption as a result of the synergistic effect between CHI and PLGA on P-glycoprotein (Pgp) inhibition. CHI/PLGA NPs showed high cellular uptake and low efflux for drugs in Caco-2 cells. The cytotoxicity studies revealed that CHI/PLGA NPs had a transient effect on the membrane integrity, but did not have an influence on cell viability. Based on the in vitro release studies, SPIP, and intracellular drug accumulation and transport investigations, we speculate rationally that CHI/PLGA NPs were mainly internalized in the form of intact NPs, thus escaping the recognition of enterocyte Pgp and avoiding efflux into the apical part of the enterocytes. After partial release of drugs inside the enterocytes, CHI/PLGA interfered with the microenvironment of Pgp and further weakened the Pgp-mediated efflux. Then, the drug-loaded NPs exited via the exocytose effect from the basal part of the enterocytes and entered the blood circulation. These results showed that CHI/PLGA NPs would be smart oral delivery carriers for antineoplastic agents that are also Pgp substrates.

  13. Transient aggregation of chitosan-modified poly(d,l-lactic-co-glycolic) acid nanoparticles in the blood stream and improved lung targeting efficiency.

    Science.gov (United States)

    Lee, Song Yi; Jung, Eunjae; Park, Ju-Hwan; Park, Jin Woo; Shim, Chang-Koo; Kim, Dae-Duk; Yoon, In-Soo; Cho, Hyun-Jong

    2016-10-15

    Chitosan (CS)-modified poly(d,l-lactic-co-glycolic) acid (PLGA) nanoparticles (NPs) were prepared and their lung targetability after intravenous administration was elucidated. PLGA NPs (mean diameter: 225nm; polydispersity index: 0.11; zeta potential: -15mV), 0.2% (w/v) CS-coated PLGA NPs (CS02-PLGA NPs, mean diameter: 264nm; polydispersity index: 0.17; zeta potential: -7mV), and 0.5% (w/v) CS-coated PLGA NPs (CS05-PLGA NPs, mean diameter: 338nm; polydispersity index: 0.23; zeta potential: 12mV) were fabricated by a modified solvent evaporation method. PLGA NPs maintained their initial particle size in different media, such as human serum albumin (HSA) solution, rat plasma, and distilled water (DW), while CS05-PLGA NPs exhibited the formation of aggregates in early incubation time and disassembly of those into the NPs in late incubation time (at 24h). According to the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis, the binding affinity of CS05-PLGA NPs with HSA and rat plasma was higher than that of PLGA NPs. By a near-infrared fluorescence (NIRF) imaging test in the mouse, the selective accumulation of CS05-PLGA NPs, rather than PLGA NPs, in lung tissue was demonstrated. These findings suggest that CS05-PLGA NPs can form transient aggregates in the blood stream after intravenous administration and markedly improve lung targeting efficiency, compared with PLGA NPs. PMID:27421112

  14. Maize silage supplementation to lower quality grass silage improves the intake, apparent digestibility and N retention in wether sheep

    Directory of Open Access Journals (Sweden)

    Ivana Matić

    2009-12-01

    Full Text Available The objective of this experiment was to study the effects of interactions between lower quality grass silage (GS dominated by orchardgrass (Dactylis glomerata L. and maize silage (MS (Zea mays L. on ad libitum intake, digestibility and N retention in wether sheep. The study consisted of four feeding treatments involving GS and MS alone, and GS and MS mixtures in ratios of 67:33 or 33:67 (DM basis fed twice daily. The GS was harvested at the beginning of flowering of orchardgrass (about 35 % of plants were in flower while the MS used was of lower DM and starch concentration (264 g kg-1 fresh weight and 211 g kg-1 DM respectively. Mean DM content of GS was 408 g kg-1 fresh weight. MS was lower in crude protein (CP (62 g kg-1 DM than the GS (98 g kg-1 DM (P<0.001. GS contained larger quantities of neutral detergent fibre (NDF and acid detergent fiber (ADF (P<0.001 than MS. Inclusion of MS in the diet (33 % vs. 67 % had positive linear effects on fresh matter (FM voluntary intake (P<0.05, digestibility of DM, organic matter (OM, digestible OM in the DM (D-value (P<0.05, starch digestibility (P<0.05, N intake (P<0.01, N output in faeces (P<0.05 and absorbed N (P<0.05. A positive associative effect of GS and MS was observed for all intake parameters measured (FM, DM, OM, NDF (quadratic, P<0.05 to P<0.01, digestibility of DM, ADF (quadratic, P<0.05, CP (quadratic, P<0.01, N intake and absorbed N (quadratic, P<0.01. It was concluded that positive interactions of GS and MS were recorded for a limited number of parameters because of the lower quality MS than required for the full benefit of two forages fed together.

  15. Economic effectiveness of irradiation with gamma rays on maize grains

    International Nuclear Information System (INIS)

    Gamma irradiation of maize grains before sowing increses the yield and improves the quality of agricultural produce. The positive results consist in the net income from silage maize from 45 to 85 per ha and from the grain maize from 85 to 109,9 per ha; the level of raw protein from the silage maize with 11,30% and from the grain maize with 6 to 12%; the level of feed units from the silage maize with 5 to 13% and from grain maize with 6 to 12%. Such direct effect in the same time is a stimulating one and raises the effectiveness of the animal production due to the better feeding of animals

  16. Chitosan supplementation and cholesterol

    Czech Academy of Sciences Publication Activity Database

    Koppová, Ingrid; Fliegerová, Kateřina; Šimůnek, Jiří; Kopečný, Jan

    Ancona : PUM, 2007, s. 6-6. [Application of Chitosan in Medical Sciences. Venezia (IT), 25.01.2007-26.01.2007] R&D Projects: GA AV ČR 1QS500200572 Institutional research plan: CEZ:AV0Z50450515 Keywords : chitosan Subject RIV: EE - Microbiology, Virology

  17. Cell-wall properties contributing to improved deconstruction by alkaline pre-treatment and enzymatic hydrolysis in diverse maize (Zea mays L.) lines

    OpenAIRE

    Li, Muyang; Heckwolf, Marlies; Crowe, Jacob D.; Williams, Daniel L.; Magee, Timothy D.; Shawn M Kaeppler; Leon, Natalia de; Hodge, David B

    2015-01-01

    A maize (Zea mays L. subsp. mays) diversity panel consisting of 26 maize lines exhibiting a wide range of cell-wall properties and responses to hydrolysis by cellulolytic enzymes was employed to investigate the relationship between cell-wall properties, cell-wall responses to mild NaOH pre-treatment, and enzymatic hydrolysis yields. Enzymatic hydrolysis of the cellulose in the untreated maize was found to be positively correlated with the water retention value, which is a measure of cell-wall...

  18. Production of Chitosan by Fungi

    Directory of Open Access Journals (Sweden)

    K. Nadarajah

    2001-01-01

    Full Text Available In this study chitosan was extracted from the mycelia of Rhizopus sp KN01, Rhizopus sp KN02, Mucor sp KN03 and Aspergillus niger with the highest amount of extractable chitosan obtained at the late exponential phase. The amount of chitosan produced varied widely amongst isolates. Mucor sp KN03 produced the highest amount of extractable chitosan per ml of substrate and the highest yield of chitosan per unit mycelia mass.

  19. Modified chitosans for biomedical applications

    OpenAIRE

    Yalınca, Zülal

    2013-01-01

    ABSTRACT: The subject of this thesis is the exploration of the suitability of chitosan and some of its derivatives for some chosen biomedical applications. Chitosan-graft-poly (N-vinyl imidazole), Chitosan-tripolyphosphate and ascorbyl chitosan were synthesized and characterized for specific biomedical applications in line with their chemical functionalities. Chitosan-graft-poly (N-vinyl imidazole), Chi-graft-PNVI, was synthesized by two methods; via an N-protection route and without N-pr...

  20. Modification of chitosan by swelling and crosslinking using epichlorohydrin as heavy metal Cr (VI) adsorbent in batik industry wastes

    Science.gov (United States)

    Hastuti, B.; Masykur, A.; Hadi, S.

    2016-02-01

    Study on chitosan modification by swelling and crosslinking and its application as a selective adsorbent for heavy metals Cr (VI) in batik industry wastes was done. Swelling is intended to improve chitosan porosity, whereas crosslinking is to increase the resistance of chitosan against acid. Natural samples are generally acidic, thus limiting chitosan application as an adsorbent. Modification of chitosan by combining swelling and crosslinking is expected to increase its adsorption capacity in binding heavy metal ions in water. The modified chitosan was later contacted with Cr (VI) to test its adsorption capacity with a variation of pH and contact time. Finally, application of modified chitosan was done in batik industry waste containing Cr (IV). Based on the results, chitosan-ECH 25% (v/v) was the optimum concentration of crosslinker to adsorb Cr (VI) ions. Modified chitosan has a solubility resistance to acids, even though a strong acid. Modification of chitosan also improved its adsorption capacity to Cr (VI) from 74% (pure chitosan) to 89% with contact time 30 min at pH 3. On the application to the batik wastes, the modified chitosan were able to adsorb Cr (IV) up to the level of 5 ppm. Thus, the modified chitosan has a potential to be applied to as an adsorbent of Cr (VI) in batik industry wastes.

  1. Genetic Improvement of Bacillus licheniformis Strains for Efficient Deproteinization of Shrimp Shells and Production of High-Molecular-Mass Chitin and Chitosan ▿ †

    Science.gov (United States)

    Hoffmann, Kerstin; Daum, Gabriele; Köster, Marina; Kulicke, Werner-Michael; Meyer-Rammes, Heike; Bisping, Bernward; Meinhardt, Friedhelm

    2010-01-01

    By targeted deletion of the polyglutamate operon (pga) in Bacillus licheniformis F11, a derivative form, F11.1 (Δpga), was obtained that, along with lacking polyglutamate (PGA) formation, displayed enhanced proteolytic activities. The phenotypic properties were maintained in a strain in which the chiBA operon was additionally deleted: F11.4 (ΔchiBA Δpga). These genetically modified strains, carrying the Δpga deletion either alone (F11.1) or together with the ΔchiBA (F11.4) deletion, were used in fermentations (20-liter scale) aiming at the deproteinization of shrimp shells in order to obtain long-chain chitin. After chemical deacetylation, the resulting chitosan samples were analyzed by nuclear magnetic resonance spectroscopy, size exclusion chromatography, and viscometry and compared to a chitosan preparation that was produced in parallel by chemical methods by a commercial chitosan supplier (GSRmbH). Though faint lipid impurities were present in the fermented polysaccharides, the viscosity of the material produced with the double-deletion mutant F11.4 (Δpga ΔchiBA) was higher than that of the chemically produced and commercially available samples (Cognis GmbH). Thus, enhanced proteolytic activities and a lack of chitinase activity render the double mutant F11.4 a powerful tool for the production of long-chain chitosan. PMID:20971870

  2. A mechanistic based approach for enhancing buccal mucoadhesion of chitosan

    DEFF Research Database (Denmark)

    Meng-Lund, Emil; Muff-Westergaard, Christian; Sander, Camilla;

    2014-01-01

    Mucoadhesive buccal drug delivery systems can enhance rapid drug absorption by providing an increased retention time at the site of absorption and a steep concentration gradient. An understanding of the mechanisms behind mucoadhesion of polymers, e.g. chitosan, is necessary for improving the...... mucoadhesiveness of buccal formulations. The interaction between chitosan of different chain lengths and porcine gastric mucin (PGM) was studied using a complex coacervation model (CCM), isothermal titration calorimetry (ITC) and a tensile detachment model (TDM). The effect of pH was assessed in all three models...... and the approach to add a buffer to chitosan based drug delivery systems is a means to optimize and enhance buccal drug absorption. The CCM demonstrated optimal interactions between chitosan and PGM at pH 5.2. The ITC experiments showed a significantly increase in affinity between chitosan and PGM at...

  3. PREPARATION AND PROPERTIES OF CHITOSAN/LIGNIN COMPOSITE FILMS

    Institute of Scientific and Technical Information of China (English)

    Long Chen; Chang-yu Tang; Nan-ying Ning; Chao-yu Wang; Qiang Fu; Qin Zhang

    2009-01-01

    Biodegradable composite films based on chitosan and lignin with various composition were prepared via the solution-casting technique.FT-IR results indicate the existence of hydrogen bonding between chitosan and lignin,and SEM images show that lignin could be well dispersed in chitosan when the content of lignin is below 20 wt% due to the strong interfacial interaction.As a result of strong interaction and good dispersion,the tensile strength,storage modulus,thermal degradation temperature and glass transition temperature of chitosan have been largely improved by adding lignin.Our work provides a simple and cheap way to prepare fully biodegradable chitosan/lignin composites,which could be used as packaging films or wound dressings.

  4. Antimicrobial coating of modified chitosan onto cotton fabrics

    Science.gov (United States)

    Cheng, Xiaoli; Ma, Kaikai; Li, Rong; Ren, Xuehong; Huang, T. S.

    2014-08-01

    Chitosan has been applied as an antibacterial agent to provide biocidal function for textiles but has limitations of application condition and durability. In this study, a new N-halamine chitosan derivative was synthesized by introducing N-halamine hydantoin precursor. The synthesized chitosan derivative 1-Hydroxymethyl-5,5-dimethylhydantoin chitosan (chitosan-HDH) was coated onto cotton fabric with 1,2,3,4-butanetetracarboxylic acid (BTCA) as a crosslinking agent. The coatings were characterized and confirmed by FT-IR and SEM. The treated cotton fabrics can be rendered excellent antimicrobial activity upon exposure to dilute household bleach. The chlorinated coated swatches can inactivate 100% of the Staphylococcus aureus and E. coli O157:H7 with a contact time of 5 min. Almost all the lost chlorine after a month of storage could be recharged upon rechlorination. The crease recovery property of the treated swatches improved while the breaking strength decreased compared with uncoated cotton.

  5. Preparation and mechanical properties of chitosan/carbon nanotubes composites.

    Science.gov (United States)

    Wang, Shao-Feng; Shen, Lu; Zhang, Wei-De; Tong, Yue-Jin

    2005-01-01

    Biopolymer chitosan/multiwalled carbon nanotubes (MWNTs) nanocomposites have been successfully prepared by a simple solution-evaporation method. The morphology and mechanical properties of the chitosan/MWNTs nanocomposites have been characterized with field emission scanning electron microscopy (SEM), bright field transmission electron microscopy (TEM), optical microscopy (OM), wide-angle X-ray diffraction (XRD), and tensile as well as nanoindentation tests. The MWNTs were observed to be homogeneously dispersed throughout the chitosan matrix. When compared with neat chitosan, the mechanical properties, including the tensile modulus and strength, of the nanocomposites are greatly improved by about 93% and 99%, respectively, with incorporation of only 0.8 wt % of MWNTs into the chitosan matrix. PMID:16283728

  6. Preparation and properties of polyvinyl acetal sponge modified by chitosan

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The polyvinyl acetal sponge modified by chitosan was prepared by adding chitosan/polyvinyl alcohol (PVA) solution during the acetalation reaction of PVA and formaldehyde.The effect of vesicant and chitosan to the pore morphology,water absorption ratio,water absorption rate,expansion time and mechanical properties were studied.The polyvinyl acetal sponge modified by chitosan was used as a hemostatic packing material for the injured rabbit nasal tissue.The hemostatic effect and the healing effect of the modified sponge on the nasal mucosa after nasal surgery were studied.The results indicated that the polyvinyl acetal sponge modified by chitosan has an interconnected pore structure and the wall between large pores also has small pores.The chitosan adhered on the inner surface of the pores.The increased content of vesicant led to an increase in pore diameter,in the water absorption ratio and in expansion time.However,there was only a small change in the water absorption rate and a decrease in tensile strength and compression strength were noted.With an increase in chitosan content,the pore diameter and interconnection of the sponge was reduced.Water absorption ratio,expansion time and water absorption rate decreased,but tensile strength and compression strength improved.Observation of the rabbit nasal tissue after surgical operation suggested that polyvinyl acetal sponge modified by chitosan has an anti-inflammatory,hemostatic and antiadherent characteristic and could promote the healing and functional recovery of rabbit nasal mucosa.

  7. Antimicrobial and physicochemical properties of chitosan-HPMC-based films.

    Science.gov (United States)

    Möller, Heike; Grelier, Stéphane; Pardon, Patrick; Coma, Véronique

    2004-10-20

    To prepare composite films from biopolymers with anti-listerial activity and moisture barrier properties, the antimicrobial efficiency of chitosan-hydroxy propyl methyl cellulose (HPMC) films, chitosan-HPMC films associated with lipid, and chitosan-HPMC films chemically modified by cross-linking were evaluated. In addition, the physicochemical properties of composite films were evaluated to determine their potential for food applications. The incorporation of stearic acid into the composite chitosan-HPMC film formulation decreased water sensitivity such as initial solubility in water and water drop angle. Thus, cross-linking of composite chitosan-HPMC, using citric acid as the cross-linking agent, led to a 40% reduction in solubility in water. The water vapor transfer rate of HPMC film, approximately 270 g x m(-2) x day(-1) x atm(-1), was improved by incorporating chitosan and was further reduced 40% by the addition of stearic acid and/or cross-linking. Anti-listerial activity of films was determined on solid medium by a numeration technique. Chitosan-HPMC-based films, with and without stearic acid, inhibited the growth of Listeria monocytogenes completely. On the other hand, a loss of antimicrobial activity after chemical cross-linking modification was observed. FTIR and 13C NMR analyses were then conducted in order to study a potential chemical modification of biopolymers such as a chemical reaction with the amino group of chitosan. To complete the study, the mechanical properties of composite films were determined from tensile strength assays. PMID:15479027

  8. Air plasma treated chitosan fibers-stacked scaffolds

    International Nuclear Information System (INIS)

    Chitosan is a nontoxic, biodegradable and biocompatible polymer. Rapid prototyped chitosan scaffolds were manufactured by liquid-frozen deposition of chitosan fibers in this study. To investigate if the air plasma (AP) treatment could be used to improve the surface properties of these scaffolds for cell attachment, chitosan films were first prepared and treated with AP under different conditions. Under the optimized condition, the water contact angle of chitosan films was significantly reduced from 90 ± 1° to 19 ± 1° after AP treatment. On the other hand, the surface charge and nanometric roughness of chitosan films increased after AP treatment. X-ray photoelectron spectroscopy measurement on AP-treated three-dimensional chitosan scaffolds showed that nitrogen and oxygen increased at each location inside the scaffolds as compared to the untreated ones, which indicated that AP could permeate through the fibrous stacks of the scaffolds and effectively modify the interior (visible) surface of the scaffolds. Moreover, AP treatment enabled the migration of MC3T3-E1 cells into the scaffolds, facilitated their proliferation and promoted the bone mineral deposition. These results suggested that fibers-stacked chitosan scaffolds may be produced by liquid-frozen deposition and treated with AP for bone tissue engineering applications. (paper)

  9. Preparation and properties of chitosan nanocomposite films reinforced by poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) treated carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Wu Tongfei; Pan Yongzheng; Bao Hongqian [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore); Li Lin, E-mail: mlli@ntu.edu.sg [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore)

    2011-10-03

    Highlights: {yields} Chitosan-based nanocomposites prepared from PEDOT-PSS treated MWCNTs. {yields} PEDOT-PSS served as a bridge to improve the dispersion of MWCNTs and interfacial compatibility between MWCNTs and chitosan. {yields} The mechanical properties of chitosan were significantly improved by PEDOT-PSS treated MWCNTs at a small loading. - Abstract: Carbon nanotube-based nanocomposites of chitosan were successfully prepared by a simple solution-evaporation method. Multiwalled carbon nanotubes (MWCNTs) were treated by poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT-PSS) in water before mixed with a chitosan solution to improve the dispersion of MWCNTs and interfacial compatibility between MWCNTs and chitosan. The morphological and mechanical properties of the prepared PEDOT-PSS/MWCNT/chitosan nanocomposites have been characterized with field emission scanning electron microscopy (FESEM) and tensile tests. MWCNTs were observed to be homogeneously dispersed throughout the chitosan matrix. As compared with the neat chitosan, the tensile strength and modulus of the nanocomposite were greatly improved by about 61% and 34%, respectively, with incorporation of only 0.5 wt.% of MWCNTs into the chitosan matrix. The comparison of mechanical properties for PEDOT-PSS/MWCNT/chitosan and pristine MWCNT/chitosan nanocomposites has been made. The hardness of the nanocomposites was also evaluated by nanoindentation.

  10. Preparation and properties of chitosan nanocomposite films reinforced by poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) treated carbon nanotubes

    International Nuclear Information System (INIS)

    Highlights: → Chitosan-based nanocomposites prepared from PEDOT-PSS treated MWCNTs. → PEDOT-PSS served as a bridge to improve the dispersion of MWCNTs and interfacial compatibility between MWCNTs and chitosan. → The mechanical properties of chitosan were significantly improved by PEDOT-PSS treated MWCNTs at a small loading. - Abstract: Carbon nanotube-based nanocomposites of chitosan were successfully prepared by a simple solution-evaporation method. Multiwalled carbon nanotubes (MWCNTs) were treated by poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT-PSS) in water before mixed with a chitosan solution to improve the dispersion of MWCNTs and interfacial compatibility between MWCNTs and chitosan. The morphological and mechanical properties of the prepared PEDOT-PSS/MWCNT/chitosan nanocomposites have been characterized with field emission scanning electron microscopy (FESEM) and tensile tests. MWCNTs were observed to be homogeneously dispersed throughout the chitosan matrix. As compared with the neat chitosan, the tensile strength and modulus of the nanocomposite were greatly improved by about 61% and 34%, respectively, with incorporation of only 0.5 wt.% of MWCNTs into the chitosan matrix. The comparison of mechanical properties for PEDOT-PSS/MWCNT/chitosan and pristine MWCNT/chitosan nanocomposites has been made. The hardness of the nanocomposites was also evaluated by nanoindentation.

  11. Application of organic matter and biofertilizer to improve growth and yield of maize on soil damaged by volcanic ash of Mount Kelud in East Java

    OpenAIRE

    S. Hardianita; R.M. Bosas; Y. Nuraini

    2015-01-01

    Volcanic ash from the eruption of Mount Kelud in 2014 damaged some agricultural areas grown with maize in Malang of East Java. The purpose of this study was to elucidate the effect of organic fertilizers and biological fertilizers on growth and yield of maize on soils damaged by volcanic ash from the eruption of Mount Kelud. A pot experiment was conducted in the glasshouse of Balitkabi, Kendalpayak, Malang from July 2014 to February 2015. The treatments tested in this study were combinations ...

  12. Chitosan and chitosan chlorhydrate based various approaches for enhancement of dissolution rate of carvedilol

    Directory of Open Access Journals (Sweden)

    Shete Amol S

    2012-12-01

    Full Text Available Abstract Background and the purpose of the study Carvedilol nonselective β-adrenoreceptor blocker, chemically (±-1-(Carbazol-4-yloxy-3-[[2-(o-methoxypHenoxy ethyl] amino]-2-propanol, slightly soluble in ethyl ether; and practically insoluble in water, gastric fluid (simulated, TS, pH 1.1, and intestinal fluid (simulated, TS without pancreatin, pH 7.5 Compounds with aqueous solubility less than 1% W/V often represents dissolution rate limited absorption. There is need to enhance the dissolution rate of carvedilol. The objective of our present investigation was to compare chitosan and chitosan chlorhydrate based various approaches for enhancement of dissolution rate of carvedilol. Methods The different formulations were prepared by different methods like solvent change approach to prepare hydrosols, solvent evaporation technique to form solid dispersions and cogrind mixtures. The prepared formulations were characterized in terms of saturation solubility, drug content, infrared spectroscopy (FTIR, differential scanning calorimetry (DSC, powder X-ray diffraction (PXRD, electron microscopy, in vitro dissolution studies and stability studies. Results The practical yield in case of hydrosols was ranged from 59.76 to 92.32%. The drug content was found to uniform among the different batches of hydrosols, cogrind mixture and solid dispersions ranged from 98.24 to 99.89%. There was significant improvement in dissolution rate of carvedilol with chitosan chlorhdyrate as compare to chitosan and explanation to this behavior was found in the differences in the wetting, solubilities and swelling capacity of the chitosan and chitosan salts, chitosan chlorhydrate rapidly wet and dissolve upon its incorporation into the dissolution medium, whereas the chitosan base, less water soluble, would take more time to dissolve. Conclusion This technique is scalable and valuable in manufacturing process in future for enhancement of dissolution of poorly water soluble

  13. Immobilization of chitosan film containing semaphorin 3A onto a microarc oxidized titanium implant surface via silane reaction to improve MG63 osteogenic differentiation

    Directory of Open Access Journals (Sweden)

    Fang K

    2014-10-01

    Full Text Available Kaixiu Fang,1,* Wen Song,2,* Lifeng Wang,1 Sen Jia,3 Hongbo Wei,1 Shuai Ren,1 Xiaoru Xu,1 Yingliang Song1 1State Key Laboratory of Military Stomatology, Department of Implant Dentistry, School of Stomatology, Fourth Military Medical University, Xi’an, People’s Republic of China; 2State Key Laboratory of Military Stomatology, Department of Prosthetic Dentistry, School of Stomatology, Fourth Military Medical University, Xi’an, People’s Republic of China; 3State Key Laboratory of Military Stomatology, Department of Oral and Maxillofacial Surgery, School of Stomatology, Fourth Military Medical University, Xi’an, People’s Republic of China *These authors contributed equally to this work Abstract: Improving osseointegration of extensively used titanium (Ti implants still remains a main theme in implantology. Recently, grafting biomolecules onto a Ti surface has attracted more attention due to their direct participation in the osseointegration process around the implant. Semaphorin 3A (Sema3A is a new proven osteoprotection molecule and is considered to be a promising therapeutic agent in bone diseases, but how to immobilize the protein onto a Ti surface to acquire a long-term effect is poorly defined. In our study, we tried to use chitosan to wrap Sema3A (CS/Sema and connect to the microarc oxidized Ti surface via silane glutaraldehyde coupling. The microarc oxidization could formulate porous topography on a Ti surface, and the covalently bonded coating was homogeneously covered on the ridges between the pores without significant influence on the original topography. A burst release of Sema3A was observed in the first few days in phosphate-buffered saline and could be maintained for >2 weeks. Coating in phosphate-buffered saline containing lysozyme was similar, but the release rate was much more rapid. The coating did not significantly affect cellular adhesion, viability, or cytoskeleton arrangement, but the osteogenic-related gene

  14. Effect of organic fertilizers on maize production in Eastern Georgia

    Science.gov (United States)

    Jolokhava, Tamar; Kenchiashvili, Naira; Tarkhnishvili, Maia; Ghambashidze, Giorgi

    2016-04-01

    Maize remains to be the most important cereal crop in Georgia. Total area of arable land under cereal crops production equals to 184 thousands hectares (FAO statistical yearbook, 2014), from which maize takes the biggest share. Leading position of maize among other cereal crops is caused by its dual purpose as food and feed product. In Spite of a relatively high production of maize to other cereals there is still a high demand on it, especially as feed for animal husbandry. The same tendency is seen in organic production, where producers of livestock and poultry products require organically grown maize, the average yield of which is much less than those produced conventionally. Therefore, it is important to increase productivity of maize in organic farms. Current study aimed to improve maize yield using locally produced organic fertilizers and to compare them to the effect of mineral fertilizers. The study was carried out in Eastern Georgia under dry subtropical climate conditions on local hybrid of maize. This is the first attempt to use hybrid maize (developed with organic plant breeding method) in organic field trials in Georgia. The results shown, that grain yield from two different types of organic fertilizers reached 70% of the yields achieved with industrial mineral fertilizers. As on farm level differences between organic and conventional maize production are much severe, the results from the field trials seems to be promising for future improvement of organic cereal crop production.

  15. The effect of calcium and chitosan metabolism to the excretion of radiostrontium in mice

    International Nuclear Information System (INIS)

    Chitosan, a natural nontoxic chelator, was reported to reduce whole body retention of radiostrontium in mice. As calcium has a similar chemical properties to strontium both of which be easily bound with hydroxyapatite structure, calcium can be either a competitor or enhancer to chitosan on the removal of radiostrontium. We compared the effect of chitosan and calcium on the excretion of ingested radiostrontium (85Sr). Chitosan or calcium(CaCl2) and usual food was mixed as 1:99 by weight. The mixed food to chitosan(group 1) or calcium(group 2) were given orally for 30 days before 85Sr administration. In other groups, mixed calcium and chitosan solution (group 3), 1% calcium (group 4), or 1% chitosan solution (group 5) was given for 7 days immediately after oral administration of 85SrCl2 (0.25μCi). In control group, no chitosan or calcium were given. Either chitosan or calcium was effective on the removal of 85Sr from mouse body (Table 1). Addition of calcium on chitosan did not improve or deteriorate the effect of chitosan on the removal of 85Sr from mouse body. In conclusion, calcium was similarly effective on the removal of 85Sr from mouse body. (author)

  16. Quantum dot/glycol chitosan fluorescent nanoconjugates

    Science.gov (United States)

    Mansur, Alexandra AP; Mansur, Herman S.

    2015-04-01

    In this study, novel carbohydrate-based nanoconjugates combining chemically modified chitosan with semiconductor quantum dots (QDs) were designed and synthesised via single-step aqueous route at room temperature. Glycol chitosan (G-CHI) was used as the capping ligand aiming to improve the water solubility of the nanoconjugates to produce stable and biocompatible colloidal systems. UV-visible (UV-vis) spectroscopy, photoluminescence (PL) spectroscopy, and Fourier transform infrared (FTIR) spectroscopy were used to characterise the synthesis and the relative stability of biopolymer-capped semiconductor nanocrystals. The results clearly demonstrated that the glycol chitosan derivative was remarkably effective at nucleating and stabilising semiconductor CdS quantum dots in aqueous suspensions under acidic, neutral, and alkaline media with an average size of approximately 2.5 nm and a fluorescent activity in the visible range of the spectra.

  17. SELECTION FOR METHIONINE AND TRYPTOPHAN CONTENT IN MAIZE

    Science.gov (United States)

    Some essential amino acids in maize are nutritionally limiting for animal diets. In plant breeding, selection to improve a population while conserving genetic variation within the population is referred to as recurrent selection. The potential of this method to improve maize populations for their ...

  18. TRACTION RESISTANCE IN CHITOSAN TREATED COTTON

    Directory of Open Access Journals (Sweden)

    LOX Wouter

    2015-05-01

    Full Text Available Nowadays natural products interest has increased. However, when some products are included on textile fibers, they have no affinity and need some binders or other kind of auxiliaries to improve the yeld of the process, and some of them are not so natural as the product which are binding and consequently the “bio” definition is missed as some of them can be considered as highly pollutant. Chitosan is a common used bonding agent for cotton. It improves the antimicrobial and antifungal activity, improves wound healing and is a non-toxic bonding agent. The biopolymer used in this work is chitosan, which is a deacetylated derivative of chitin. These properties depend on the amount of deacetylation (DD and the Molecular weight (MW. Along with these improving properties, as it requires some acid pH to ve solved the treatment with chitosan can have some decreasing mechanical properties. The aim of that paper is to evaluate the change in breaking force of the treated samples and a change in elongation of those samples. It compared different amounts of concentration of chitosan with non treated cotton. The traction resistance test were performed on a dynamometer. The test was conducted according to the UNE EN ISO 13934-1 standard.

  19. Carvacrol affects interfacial, structural and transfer properties of chitosan coatings applied onto polyethylene.

    Science.gov (United States)

    Kurek, Mia; Brachais, Claire-Hélène; Sčetar, Mario; Voilley, Andrée; Galić, Kata; Couvercelle, Jean-Pierre; Debeaufort, Frédéric

    2013-08-14

    Different chitosan coating solutions were tested with the aim of investigating their adhesion and wettability onto polyethylene film to improve packaging performance and provide antimicrobial properties. Surface wetting kinetics was monitored by contact angle measurements. Addition of ethanol and carvacrol improved wettability and adhesion of the thin chitosan layer. Structure, water vapour, O2, CO2 and air permeabilities of self supported chitosan films and coated polyethylene were determined. The formation of a thin chitosan layer on polyethylene improved gas barrier properties decreasing the Permeability Coefficient for oxygen and carbon dioxide ( [Formula: see text] , [Formula: see text] ) from 100 to 10,000 times. Presence of carvacrol in the chitosan coating layer increased [Formula: see text] , [Formula: see text] and Pair by a factor of ten. Moreover, it influenced film microstructure. However chitosan was shown to be good gas barrier film in the dry state. PMID:23769540

  20. Improved Nutritive Quality and Salt Resistance in Transgenic Maize by Simultaneously Overexpression of a Natural Lysine-Rich Protein Gene, SBgLR, and an ERF Transcription Factor Gene, TSRF1

    Directory of Open Access Journals (Sweden)

    Meizhen Wang

    2013-04-01

    conditions. After salt treatment, the expressions of the ten stress-related genes were significantly induced in both wild-type (WT and transgenic lines. However, compared to WT, the increases of ZmP5CS1 in all these three transgenic lines and ZmP5CS2 in line 9–10 were less than WT plants. This study provides an effective approach of maize genetic engineering for improved nutritive quality and salt tolerance.

  1. Physical stability and moisture sorption of aqueous chitosan-amylose starch films plasticized with polyols

    DEFF Research Database (Denmark)

    Cervera, Mirna Fernández; Karjalainen, Milja; Airaksinen, Sari;

    2004-01-01

    The short-term stability and the water sorption of films prepared from binary mixtures of chitosan and native amylose maize starch (Hylon VII) were evaluated using free films. The aqueous polymer solutions of the free films contained 2% (w/w) film formers, glycerol, or erythritol as a plasticizer...... crystallinity of the films are evident within a 3-month period of storage, and the changes in the solid state are dependent on the plasticizer and storage conditions. When stored at ambient conditions for 3 months, the aqueous chitosan-amylose starch films plasticized with erythritol exhibited a partly...

  2. Chitosan in Plant Protection

    OpenAIRE

    Abdelbasset El Hadrami; Adam, Lorne R.; Ismail El Hadrami; Fouad Daayf

    2010-01-01

    Chitin and chitosan are naturally-occurring compounds that have potential in agriculture with regard to controlling plant diseases. These molecules were shown to display toxicity and inhibit fungal growth and development. They were reported to be active against viruses, bacteria and other pests. Fragments from chitin and chitosan are known to have eliciting activities leading to a variety of defense responses in host plants in response to microbial infections, including the accumulation of ph...

  3. Chitosan against cutaneous pathogens

    OpenAIRE

    Champer, Jackson; Patel, Julie; Fernando, Nathalie; Salehi, Elaheh; Wong, Victoria; Kim, Jenny

    2013-01-01

    Propionibacterium acnes and Staphylococcus aureus are cutaneous pathogens that have become increasingly resistant to antibiotics. We sought to determine if chitosan, a polymer of deacetylated chitin, could be used as a potential treatment against these bacteria. We found that higher molecular weight chitosan had superior antimicrobial properties compared to lower molecular weights, and that this activity occurred in a pH dependent manner. Electron and fluorescence microscopy revealed that chi...

  4. Antimicrobial actions of degraded and native chitosan against spoilage organisms in laboratory media and foods.

    Science.gov (United States)

    Rhoades, J; Roller, S

    2000-01-01

    The objective of this study was to determine whether chitosan (poly-beta-1,4-glucosamine) and hydrolysates of chitosan can be used as novel preservatives in foods. Chitosan was hydrolyzed by using oxidative-reductive degradation, crude papaya latex, and lysozyme. Mild hydrolysis of chitosan resulted in improved microbial inactivation in saline and greater inhibition of growth of several spoilage yeasts in laboratory media, but highly degraded products of chitosan exhibited no antimicrobial activity. In pasteurized apple-elderflower juice stored at 7 degrees C, addition of 0.3 g of chitosan per liter eliminated yeasts entirely for the duration of the experiment (13 days), while the total counts and the lactic acid bacterial counts increased at a slower rate than they increased in the control. Addition of 0.3 or 1.0 g of chitosan per kg had no effect on the microbial flora of hummus, a chickpea dip; in the presence of 5.0 g of chitosan per kg, bacterial growth but not yeast growth was substantially reduced compared with growth in control dip stored at 7 degrees C for 6 days. Improved antimicrobial potency of chitosan hydrolysates like that observed in the saline and laboratory medium experiments was not observed in juice and dip experiments. We concluded that native chitosan has potential for use as a preservative in certain types of food but that the increase in antimicrobial activity that occurs following partial hydrolysis is too small to justify the extra processing involved. PMID:10618206

  5. The Use of chitosan in The Formation of Silver Nanoparticles, Chitosanic Nanoparticles and Fibrous Structures

    Science.gov (United States)

    Abdelgawad, Abdelrahman Mohamed

    Nanoscale materials have attracted much attention in the last two decades due to their unique properties. The size effect attains new chemical and physical properties to these materials. Nanoparticles and nanofiber are major component of nanomaterials and they have heavily investigated in the literature for different applications. Nanoparticles could be produced from both metals as well as polymers. Chitosan, which is a natural polymer, can be used as capping agent in the preparation of metallic nanoparticles and itself, can produce nanoparticles. The utilization of nanoparticles and nanofibers for wound dressing materials is a very popular approach. Acquiring antibacterial properties to the wound dressing materials could be obtained either by formulation of nanomaterials composites or direct chemical modification of the substance. To improve the antibacterial properties of chitosan two approaches were applied. First, is through the formulation of chitosan with silver nanoparticles and the formation of nanofiber mats. In this study, the concepts of green chemistry were applied and silver nanoparticles were prepared in high concentration using chitosan as a capping polymer and glucose as a reducing agent. Nanofiber mats of polyvinyl alcohol/chitosan/silvernanoparticles were produced via electrospinning. The antibacterial activity of these fibers shows bactericidal effect against E. coli at low concentrations of Ag-NPs. In the second approach, direct chemical modification of chitosan was performed by grafting of Iodoacetic acid to the amino group at carbon-2. The chemical structure of chitosan Iodoacetamide derivative (CIA) was confirmed by FTIR and H1-NMR. The derivative was amorphous and water soluble at neutral pH. The minimum inhibitory concentration of CIA, against E. coli, was 400ig/mL and the derivative was bacteriostatic after 4h of treatment. Nanofiber mats of polyvinyl alcohol/chitosan/chitosan Iodoacetamide were produced via electrospinning. The

  6. Mixed Compound of DCPTA and CCC Increases Maize Yield by Improving Plant Morphology and Up-Regulating Photosynthetic Capacity and Antioxidants.

    Directory of Open Access Journals (Sweden)

    Yongchao Wang

    Full Text Available DCPTA (2-diethylaminoethyl-3, 4-dichlorophenylether and CCC (2-chloroethyltrimethyl- ammonium chloride have a great effect on maize growth, but applying DCPTA individually can promote the increase of plant height, resulting in the rise of lodging percent. Plant height and lodging percent decrease in CCC-treated plants, but the accumulation of biomass reduce, resulting in yield decrease. Based on the former experiments, the performance of a mixture which contained 40 mg DCPTA and 20 mg CCC as active ingredients per liter of solution, called PCH was tested with applying 40mg/L DCPTA and 20mg/L CCC individually. Grain yield, yield components, internode characters, leaf area per plant, plant height and lodging percent as well as chlorophyll content, chlorophyll fluorescence, enzymatic antioxidants, membranous peroxide and organic osmolyte were analyzed in two years (2011 and 2012, using maize hybrid, Zhengdan 958 (ZD 958 at density of 6.75 plants m-2. CCC, DCPTA and PCH were sprayed on the whole plant leaves at 7 expanded leaves stage and water was used as control. Compared to control, PCH significantly increased grain yield (by 9.53% and 6.68% from 2011 to 2012. CCC significantly decreased kernel number per ear (by 6.78% and 5.69% and thousand kernel weight (TKW (by 8.57% and 6.55% from 2011 to 2012. Kernel number per ear and TKW increased in DCPTA-treated and PCH-treated plants, but showed no significant difference between them. In CCC-treated and PCH-treated plants, internode length and plant height decreased, internode diameter increased, resulting in the significant decline of lodging percent. With DCPTA application, internode diameter increased, but internode length and plant height increased at the same time, resulting in the augment of lodging percent. Bending strength and puncture strength were increased by applying different plant growth regulators (PGRs. In PCH-treated plants, bending strength and puncture strength were greater than other

  7. Mixed Compound of DCPTA and CCC Increases Maize Yield by Improving Plant Morphology and Up-Regulating Photosynthetic Capacity and Antioxidants.

    Science.gov (United States)

    Wang, Yongchao; Gu, Wanrong; Xie, Tenglong; Li, Lijie; Sun, Yang; Zhang, He; Li, Jing; Wei, Shi

    2016-01-01

    DCPTA (2-diethylaminoethyl-3, 4-dichlorophenylether) and CCC (2-chloroethyltrimethyl- ammonium chloride) have a great effect on maize growth, but applying DCPTA individually can promote the increase of plant height, resulting in the rise of lodging percent. Plant height and lodging percent decrease in CCC-treated plants, but the accumulation of biomass reduce, resulting in yield decrease. Based on the former experiments, the performance of a mixture which contained 40 mg DCPTA and 20 mg CCC as active ingredients per liter of solution, called PCH was tested with applying 40mg/L DCPTA and 20mg/L CCC individually. Grain yield, yield components, internode characters, leaf area per plant, plant height and lodging percent as well as chlorophyll content, chlorophyll fluorescence, enzymatic antioxidants, membranous peroxide and organic osmolyte were analyzed in two years (2011 and 2012), using maize hybrid, Zhengdan 958 (ZD 958) at density of 6.75 plants m-2. CCC, DCPTA and PCH were sprayed on the whole plant leaves at 7 expanded leaves stage and water was used as control. Compared to control, PCH significantly increased grain yield (by 9.53% and 6.68%) from 2011 to 2012. CCC significantly decreased kernel number per ear (by 6.78% and 5.69%) and thousand kernel weight (TKW) (by 8.57% and 6.55%) from 2011 to 2012. Kernel number per ear and TKW increased in DCPTA-treated and PCH-treated plants, but showed no significant difference between them. In CCC-treated and PCH-treated plants, internode length and plant height decreased, internode diameter increased, resulting in the significant decline of lodging percent. With DCPTA application, internode diameter increased, but internode length and plant height increased at the same time, resulting in the augment of lodging percent. Bending strength and puncture strength were increased by applying different plant growth regulators (PGRs). In PCH-treated plants, bending strength and puncture strength were greater than other treatments

  8. STRATEGY OF MAIZE'S CONCENTRATING TO ADVANTAGE AREAS IN JILIN PROVINCE

    Institute of Scientific and Technical Information of China (English)

    JIANG Hui-ming; GU Li-li

    2003-01-01

    Jilin Province is one of the main grain-producing provinces of China, which has dominant position in maize production, by the view of its advantages in policy, location, breed and market. And after entering WTO,some measures have been taken to enhance maize competitive ability. But there are some difficulties in concentrating production to maize advantaged areas. This paper expounds the basis that Jilin Province becomes the advantage area of maize, analyzes the problems and puts forward the supporting policy. Some strategic measures are proposed,as developing comparable advantages, carrying out the strategy of un-equilibrium development and cultivating advantaged product areas of maize to rapidly improve the international competitive ability and productivity of maize in Jilin Province, cast the agricultural predicament off and promote the agricultural development into a new stage.

  9. Preparation of pure chitosan film using ternary solvents and its super absorbency.

    Science.gov (United States)

    Wang, Xuejun; Lou, Tao; Zhao, Wenhua; Song, Guojun

    2016-11-20

    Chemical modification and graft copolymerization were commonly adopted to prepare super absorbent materials. However, physical microstructure of pure chitosan film was optimized to improve the water uptake capacity in this study. Chitosan films with micro-nanostructure were prepared by a ternary solvent system. The optimal process parameters are 1% acetic acid water solution: dioxane: dimethyl sulfoxide=90: 2.5: 7.5 (v/v/v) with chitosan concentration at 1.25% (w/v). The water uptake capacity of the chitosan film prepared under the optimal process parameters was 896g/g. The prepared chitosan films also exhibited high water uptake capacity in response to external stimuli such as temperature, pH and salt. This finding may provide another way for improving the water absorbency. The pure chitosan film may find potential applications especially in the fields of hygienic products and biomedicine due to its super water absorbency and nontoxicity. PMID:27561494

  10. Thermal and magnetic properties of chitosan-iron oxide nanoparticles.

    Science.gov (United States)

    Soares, Paula I P; Machado, Diana; Laia, César; Pereira, Laura C J; Coutinho, Joana T; Ferreira, Isabel M M; Novo, Carlos M M; Borges, João Paulo

    2016-09-20

    Chitosan is a biopolymer widely used for biomedical applications such as drug delivery systems, wound healing, and tissue engineering. Chitosan can be used as coating for other types of materials such as iron oxide nanoparticles, improving its biocompatibility while extending its range of applications. In this work iron oxide nanoparticles (Fe3O4 NPs) produced by chemical precipitation and thermal decomposition and coated with chitosan with different molecular weights were studied. Basic characterization on bare and chitosan-Fe3O4 NPs was performed demonstrating that chitosan does not affect the crystallinity, chemical composition, and superparamagnetic properties of the Fe3O4 NPs, and also the incorporation of Fe3O4 NPs into chitosan nanoparticles increases the later hydrodynamic diameter without compromising its physical and chemical properties. The nano-composite was tested for magnetic hyperthermia by applying an alternating current magnetic field to the samples demonstrating that the heating ability of the Fe3O4 NPs was not significantly affected by chitosan. PMID:27261762

  11. Remediation of coal mining wastewaters using chitosan microspheres.

    Science.gov (United States)

    Geremias, R; Pedrosa, R C; Benassi, J C; Fávere, V T; Stolberg, J; Menezes, C T B; Laranjeira, M C M

    2003-12-01

    This study aimed to evaluate the potential use of chitosan and chitosan/poly(vinylalcohol) microspheres incorporating with tetrasulphonated copper (II) phthalocyanine (CTS/PVA/TCP) in the remediation of coal mining wastewaters. The process was monitored by toxicity tests both before and after adsorption treatments with chitosan and microspheres. Physicochemical parameters, including pH and trace-metal concentration, as well as bioindicators of water pollution were used to that end. Wastewater samples colleted from drainage of underground coal mines, decantation pools, and contaminated rivers were scrutinized. Acute toxicity tests were performed using the Brine Shrimp Test (BST) in order to evaluate the remediation efficiency of different treatments. The results showed that the pH of treated wastewater samples were improved to values close to neutrality. Chitosan treatments were also effective in removing trace-metals. Pre-treatment with chitosan followed by microsphere treatment (CTS/PVA/TCP) was more effective in decreasing toxicity than the treatment using only chitosan. This was probably due to the elimination of pollutants other than trace-metals. Thus, the use of chitosan and microspheres is an adequate alternative towards remediation of water pollution from coal mining. PMID:14977147

  12. Synthesis and evaluation of chitosan-Vitamin C complex

    Directory of Open Access Journals (Sweden)

    Tian X

    2009-01-01

    Full Text Available Chitosan is a biocompatible, biodegradable and non-toxic polysaccharide polymer. It dissolves in water only if the pH is lower than 6.5. To extend its range of application, many water-soluble derivatives have therefore been prepared. In this research, chitosan-vitamin C complex was synthesized and characterized with Fourier transformed infrared spectroscopy, differential scanning calorimetry and 1 H-NMR. The solubility of chitosan-vitamin C complex in distilled water was greatly improved. The ·O2 - scavenging activity of chitosan-vitamin C complex was compared with chitosan and vitamin C by measuring the auto-oxidation rate of pyrogallic acid. Results showed that the scavenging activity on ·O2 - by chitosan-vitamin C complex was stronger than that by CS. At low concentrations (< 0.05 mg/ml, the scavenging activity of chitosan-vitamin C complex was stronger than that of vitamin C, but after certain concentrations (>0.1mg/ml, its scavenging activity was lower than that of vitamin C.

  13. Remediation of coal mining wastewaters using chitosan microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Geremias, R.; Pedrosa, R.C.; Benassi, J.C.; Favere, V.T.; Stolberg, J.; Menezes, C.T.B.; Laranjeira, M.C.M. [Federal University of Santa Catarina, Florianopolis (Brazil)

    2003-12-01

    This study aimed to evaluate the potential use of chitosan and chitosan/poly(vinylalcohol) microspheres incorporating tetrasulphonated copper (II) phthalocyanine (CTS / PVA / TCP) in the remediation of coal mining wastewaters. The process was monitored by toxicity tests both before and after adsorption treatments with chitosan and microspheres. Physicochemical parameters, including pH and trace-metal concentration, as well as bioindicators of water pollution were used to that end. Wastewater samples collected from drainage of underground coal mines, decantation pools, and contaminated rivers were scrutinized. Acute toxicity tests were performed using the Brine Shrimp Test (BST) in order to evaluate the remediation efficiency of different treatments. The results showed that the pH of treated wastewater samples were improved to values close to neutrality. Chitosan treatments were also effective in removing trace-metals. Pre-treatment with chitosan followed by microsphere treatment (CTS / PVA / TCP) was more effective in decreasing toxicity than the treatment using only chitosan. This was probably due to the elimination of pollutants other than trace-metals. Thus, the use of chitosan and microspheres is an adequate alternative towards remediation of water pollution from coal mining.

  14. PLA/chitosan/keratin composites for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Tanase, Constantin Edi, E-mail: etanase@live.com [Faculty of Medical Bioengineering, ‘Grigore T. Popa’ University of Medicine and Pharmacy, 9-13 Kogalniceanu Street, 700454 Iasi (Romania); Spiridon, Iuliana [“Petru Poni” Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487 Iasi (Romania)

    2014-07-01

    Novel composites based on PLA, chitosan and keratin was obtained via blend preparation. The goal of this contribution was to evaluate mechanical and in vitro behavior of the composites. The results point out composites with improved Young modulus and decreased tensile strength, significant increase in hardness (compared to PLA) and a good uptake of the surface properties. Biological assessments using human osteosarcoma cell line on these composites indicate a good viability/proliferation outcome. Hence preliminary results regarding mechanical behavior and in vitro osteoblast response suggest that these composites might have prospective application in medical field. - Highlights: • PLA, chitosan and keratin composites are prepared by blend preparation. • PLA, chitosan and keratin composites present improved mechanical properties and water uptake compare to PLA. • PLA, chitosan and keratin composites present good in vitro behavior.

  15. PLA/chitosan/keratin composites for biomedical applications

    International Nuclear Information System (INIS)

    Novel composites based on PLA, chitosan and keratin was obtained via blend preparation. The goal of this contribution was to evaluate mechanical and in vitro behavior of the composites. The results point out composites with improved Young modulus and decreased tensile strength, significant increase in hardness (compared to PLA) and a good uptake of the surface properties. Biological assessments using human osteosarcoma cell line on these composites indicate a good viability/proliferation outcome. Hence preliminary results regarding mechanical behavior and in vitro osteoblast response suggest that these composites might have prospective application in medical field. - Highlights: • PLA, chitosan and keratin composites are prepared by blend preparation. • PLA, chitosan and keratin composites present improved mechanical properties and water uptake compare to PLA. • PLA, chitosan and keratin composites present good in vitro behavior

  16. Effectiveness of Gamma Irradiated Chitosan for Fresh Meat Preservation

    International Nuclear Information System (INIS)

    Chitosan is a food preservative of natural origin that has drawn the attention of scientists working in the field of radiation processing and natural polymer products development. The effectiveness of 1% chitosan (CS) and chitosan oligosaccharides (COS) (chitosan subjected to γ irradiation, 50 or 100 kGy) dipping to preserve fresh beef slices during refrigerated storage was investigated. The microbiological quality, lipid and color stability were evaluated. The results revealed that dipping in 1% CS, COS 50 and COS 100 significantly (Ρ< 0.05) improved the microbiological quality and reduced lipid oxidation in beef samples compared to the control samples. On day 7, control samples were considered rejected from the microbiological and lipid oxidation point of view. Dipping in 1% COS 100 significantly (p< 0.05) influenced color properties compared with the other groups. It could be concluded that dipping in 1% COS improved quality parameters of fresh beef and could be used in preservation.

  17. The Physical and Genetic Framework of the B73 Maize Genome

    Science.gov (United States)

    Corn (Maize) is a major cereal crop and an important model system for basic biological research. Knowledge gained from maize research can also be used to genetically improve its grass relatives such as sorghum, wheat, rice. The primary objective of the Maize Genome Sequencing Consortium (MGSC) was t...

  18. MADS-box genes in maize: Frequent targets of selection during domestication

    Science.gov (United States)

    MADS-box genes encode transcription factors that are key regulators of plant inflorescence and flower development. We examined DNA sequence variation in 32 maize MADS-box genes and 32 random loci from the maize genome and investigated their involvement in maize domestication and improvement. Using n...

  19. Synthesis and optimization of chitosan nanoparticles: Potential applications in nanomedicine and biomedical engineering

    OpenAIRE

    Ghadi, Arezou; Mahjoub, Soleiman; Tabandeh, Fatemeh; Talebnia, Farid

    2014-01-01

    Background: Chitosan nanoparticles have become of great interest for nanomedicine, biomedical engineering and development of new therapeutic drug release systems with improved bioavailability, increased specificity and sensitivity, and reduced pharmacological toxicity. The aim of the present study was to synthesis and optimize of the chitosan nanoparticles for industrial and biomedical applications. Methods: Fe3O4 was synthesized and optimized as magnetic core nanoparticles and then chitosan ...

  20. Properties of Chitosan-Genipin Films Grafted with Phenolic Compounds from Red Wine

    OpenAIRE

    Gonçalves, Fernando Jorge

    2015-01-01

    Chitosan has been studied as a renewable biopolymer to form edible films and coatings to improve the shelf life of food products. Chemical modification of chitosan is a strategy to prepare chitosan films with enhanced properties to be used as food preservatives. Wine, particularly red wine, is a rich natural source of phenolic compounds, namely anthocyanins, proanthocyanidins, monomeric catechins, and phenolic acids. Phenolic compounds, in general, present strong antioxidant properties. The a...

  1. THE DEVELOPMENT OF CHITOSAN NANOPARTICLES FROM HIBISCUS SABDARIFFA L CALYX EXTRACT FROM INDONESIA AND THAILAND

    OpenAIRE

    Nurkhasanah*, Tedjo Yuwono, Laela Hayu Nurani, Muhammad Ikhwan Rizki and Krisana Kraisintu

    2015-01-01

    Rosella (Hibiscus sabdariffa L) calyx has been reported to have an antioxidant activity. Antocyanidin is the major compound of rosella and has low bioavailability as an ionic form. Rosella extract is an ucceptable due to high acidity. Development of chitosan nanoparticle from Hibiscus sabdariffa extract were expected to improve the bioavailability and the acidity problem. We studied the optimum pH and composition ratios of chitosan, extract and tripolyphosphate (TPP) to develop chitosan-nanop...

  2. Mitigation of the Adverse Effects of Salt Stress on Maize (Zea Mays L.) Through Organic Amendments

    OpenAIRE

    Debasish Kumar Das; Bijaya Rani Dey; M.Joinul Abedin Mian; Md. Anamul Hoque

    2013-01-01

    Salinity is a major limiting factor for crop production in coastal areas of Bangladesh. Organic amendments could contribute to the improvement of crop production in coastal areas. Two maize cultivars (BARI Hybrid Maize-5 and Hybrid Maize Pacific-987) were grown in pots to investigate the mitigating adverse effects of salt stress in maize by organic amendments. Two doses of farmyard manure (FYM) and poultry manure (PM) were mixed with soils before seed sowing. Plants were subjected to salinity...

  3. Implementation and optimization of the doubled haploid technology for tropical maize (Zea mays L.) breeding programs

    OpenAIRE

    Prigge, Vanessa

    2012-01-01

    Doubled haploid (DH) technology is currently the fastest way to achieve homozygosity in maize and it offers numerous quantitative genetic, operational, and economic advantages. Hybrid maize breeding with DH lines is common in temperate areas, yet adoption of this technology is still to be realized in tropical areas. Therefore, the main goal of my thesis project was to establish and validate the DH technology for tropical maize breeding programs at the International Maize and Wheat Improvement...

  4. A COST BENEFIT ANALYSIS OF MAIZE PRODUCTION AND MARKETING IN UGANDA

    OpenAIRE

    Glenn P. Jenkins; Leonard Leung

    2013-01-01

    Maize is important in Uganda because of its dual function both as an income-generating cash crop and as a staple crop that improves food security. Three interventions on the maize sector are selected for a substantive cost-benefit analysis investigation, namely: 1. "Increasing the utilization of commercial inputs"- the focus of the intervention is to overcome the low maize yield situation in Uganda. The purpose of this study is to determine if financial and economic conditions allow the maize...

  5. 10 Reasons to be Tantalized by the B73 Maize Genome

    OpenAIRE

    Fusheng Wei; Jianwei Zhang; Shiguo Zhou; Ruifeng He; Mary Schaeffer; Kristi Collura; David Kudrna; Faga, Ben P.; Marina Wissotski; Wolfgang Golser; Rock, Susan M.; Graves, Tina A.; Fulton, Robert S.; Ed Coe; Patrick S Schnable

    2009-01-01

    Maize is a major cereal crop and an important model system for basic biological research. Knowledge gained from maize research can also be used to genetically improve its grass relatives such as sorghum, wheat, and rice. The primary objective of the Maize Genome Sequencing Consortium (MGSC) was to generate a reference genome sequence that was integrated with both the physical and genetic maps. Using a previously published integrated genetic and physical map, combined with in-coming maize geno...

  6. Effect Of Chitosan Application On The Performance Of Lentil Genotypes Under Rainfed Conditions

    Directory of Open Access Journals (Sweden)

    Janmohammadi Mohsen

    2014-12-01

    Full Text Available In the current study, influences of chitosan solutions on morphological characteristics, growth and yield components of lentil (Lens culinaris Med. under rainfed conditions have been investigated. A field experiment was conducted in the Northwest of Iran using a split-plot experiment based on a completely randomized design with three replications. The response of twelve genotypes with different origins to chitosan application at the sowing (seed soaking, vegetative and reproductive stage (spraying chitosan onto leaves was evaluated. Results revealed that chitosan application could significantly improve the number of pods per plant, 100-seed weight, grain yield per plant and harvest index in comparison to control plants. The comparison of yield components between chitosan treatments showed that spraying chitosan during the reproductive stage was more efficient than in other stages. However, the responses of the number of pods per plants and grain yield per plants to chitosan treatments were significantly different among the genotypes. Although the highest grain yield was recorded in the 78S 26013 genotype (from Jordan, its response to chitosan treatments was different from the other genotypes and showed the best performance in plants obtained from seed soaked in chitosan solutions. We suggest that the application of chitosan as an agronomic management strategy be further investigated for an efficient technique to induce resistance in lentil plants against biotic and drought stress in semi-arid regions.

  7. Comparison of chitosan nanoparticles and chitosan hydrogels for vaccine delivery

    DEFF Research Database (Denmark)

    Gordon, Sarah; Saupe, Anne; McBurney, Warren;

    2008-01-01

    In this work the potential of chitosan nanoparticles (CNP) and thermosensitive chitosan hydrogels as particulate and sustained release vaccine delivery systems was investigated. CNP and chitosan hydrogels were prepared, loaded with the model protein antigen ovalbumin (OVA) and characterised. The...... release of fluorescently-labelled OVA (FITC-OVA) from CNP and chitosan hydrogels in-vitro showed that approximately 50% of the total protein was released from CNP within a period of ten days; release of antigen from chitosan gel occurred in a more sustained manner, with <10% of total protein being...... released after 10 days. The slow release from gel formulations may be explained by the strong interactions of the protein with chitosan. While OVA-loaded CNP showed no significant immunogenicity, formulations of OVA in chitosan gel were able to stimulate both cell-mediated and humoral immunity in-vivo....

  8. Ion beam biotechnology and its application to maize breeding

    International Nuclear Information System (INIS)

    Since the mid of 1980's, ion beam had been widely used in mutagenic breeding of various crops. Ion beam biotechnology had provided a new way for improving corn variety and creating new germplasm resources, and had promoted the development of maize breeding. The ion beam characteristics, the mutagenic mechanism and its application in maize breeding were described. (authors)

  9. Influence of Seed Coating Formulations on Maize Production

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Effects of four coating formulations on maize production were studied. The results showec that all coating formulations had some effects on improving maize seedlings, strengthening the resistance againt diseases and pests and increasing the yields in dtifferent degrees, especially Paxil which increased the com yield by 12.0%, significantly higher than the control.

  10. Chitosan-film enhanced chitosan nerve guides for long-distance regeneration of peripheral nerves.

    Science.gov (United States)

    Meyer, Cora; Stenberg, Lena; Gonzalez-Perez, Francisco; Wrobel, Sandra; Ronchi, Giulia; Udina, Esther; Suganuma, Seigo; Geuna, Stefano; Navarro, Xavier; Dahlin, Lars B; Grothe, Claudia; Haastert-Talini, Kirsten

    2016-01-01

    Biosynthetic nerve grafts are developed in order to complement or replace autologous nerve grafts for peripheral nerve reconstruction. Artificial nerve guides currently approved for clinical use are not widely applied in reconstructive surgery as they still have limitations especially when it comes to critical distance repair. Here we report a comprehensive analysis of fine-tuned chitosan nerve guides (CNGs) enhanced by introduction of a longitudinal chitosan film to reconstruct critical length 15 mm sciatic nerve defects in adult healthy Wistar or diabetic Goto-Kakizaki rats. Short and long term investigations demonstrated that the CNGs enhanced by the guiding structure of the introduced chitosan film significantly improved functional and morphological results of nerve regeneration in comparison to simple hollow CNGs. Importantly, this was detectable both in healthy and in diabetic rats (short term) and the regeneration outcome almost reached the outcome after autologous nerve grafting (long term). Hollow CNGs provide properties likely leading to a wider clinical acceptance than other artificial nerve guides and their performance can be increased by simple introduction of a chitosan film with the same advantageous properties. Therefore, the chitosan film enhanced CNGs represent a new generation medical device for peripheral nerve reconstruction. PMID:26517563

  11. Synthesis of conjugated chitosan and its effect on drug permeation from transdermal patches

    Directory of Open Access Journals (Sweden)

    B K Satheeshababu

    2013-01-01

    Full Text Available The aim of this study was to synthesis the conjugated chitosan by covalent attachment of thiol moieties to the cationic polymer, mediated by a carbodiimide to improve permeation properties of chitosan. Thioglycolic acid was covalently attached to chitosan by the formation of amide bonds between the primary amino groups of the polymer and the carboxylic acid groups of thioglycolic acid. Hence, these polymers are called as thiomers or thiolated polymers. Conjugation of chitosan was confirmed by Fourier transform-infrared and differential scanning calorimetric analysis. Matrix type transdermal patches of carvedilol were prepared using the different proportions of chitosan and chitosan-thioglycolic acid conjugates (2:0, 1.7:0.3, 1.4:0.6, 1:1, 0.6:1.4 and 0.3:1.7 by solvent casting technique. Prepared matrix type patches were evaluated for their physicochemical characterization followed by in vitro evaluation. Selected formulations were subjected for their ex vivo studies on Wistar albino rat skin and human cadaver skin using the modified Franz diffusion cell. As the proportion of conjugated chitosan increased, the transdermal patches showed increased drug permeation. The mechanism of drug release was found to be nonFickian profiles. The present study concludes that the transdermal patches of carvedilol using conjugated chitosan with different proportions of chitosan were successfully developed to provide improved drug permeation. The transdermal patches can be a good approach to improve drug bioavailability by bypassing the extensive hepatic first-pass metabolism of the drug.

  12. FINANCIAL AND RISK ANALYSIS OF MAIZE TECHNOLOGY IN ETHIOPIA, BASED ON CERES-MAIZE MODEL RESULTS

    OpenAIRE

    Crawford, Eric W.; Howard, Julie A.; Kelly, Valerie A.

    2000-01-01

    This paper presents a financial and risk analysis of improved versus traditional maize production technology in Ethiopia, based on yields simulated with the CERES-Maize crop growth model (Schulthess and Ward, 2000). The purpose is to analyze the potential performance of the SG2000/Ministry of Agriculture program technology under less favorable meteorological conditions (rainfall level and distribution), and in areas with lower agroecological potential than those covered by the SG2000/MOA prog...

  13. [Characteristics of farmland eco-environment at the intercropping stage of maize intercropped with winter wheat and their effects on seedling growth of summer maize].

    Science.gov (United States)

    Zhu, Yuan-gang; Li, Hong-jie; Cui, Xin-yan; Jia, Chun-lan; Yang, Jin-sheng; Liu, Shao-kun; Zhang, Ji-wang; Dong, Shu-ting

    2015-07-01

    To study the farmland eco-environment of intercropping maize with wheat at the intercropping stage and its influence on maize seedling growth, two summer maize cultivars, Zhengdan 958 and Denghai 661, were either intercropped with wheat or directly seeded. The result demonstrated that there was little difference for the soil water content of the farmland between the two cultivation methods. The highest soil temperature of intercropped maize was 4.8-5.2 °C lower than the soil temperature of directly-seeded maize, and the lowest temperature of the intercropped maize was 1.4-1.7 °C lower. But, the temperatures for both planting methods met the requirement for seed germination. Light intensity on the ground surface of the intercropped maize was 4.4%-10.6% less than natural light, and insufficient light was the main reason for the weak and late seedling. Compared to the directly-seeded maize, the speeds of seed germination and accumulation of dry matters of the intercropped maize were relatively slow. On the whole, the seedling of intercropped maize was not strong, which presented small leaves, short height and low chlorophyll content. The restraint on the growth of intercropped maize was enhanced with the extension of intercropping period. For farm planting, direct-seeding could improve the seed germination and seedling growth of summer maize. PMID:26710624

  14. DNA/chitosan electrostatic complex.

    Science.gov (United States)

    Bravo-Anaya, Lourdes Mónica; Soltero, J F Armando; Rinaudo, Marguerite

    2016-07-01

    Up to now, chitosan and DNA have been investigated for gene delivery due to chitosan advantages. It is recognized that chitosan is a biocompatible and biodegradable non-viral vector that does not produce immunological reactions, contrary to viral vectors. Chitosan has also been used and studied for its ability to protect DNA against nuclease degradation and to transfect DNA into several kinds of cells. In this work, high molecular weight DNA is compacted with chitosan. DNA-chitosan complex stoichiometry, net charge, dimensions, conformation and thermal stability are determined and discussed. The influence of external salt and chitosan molecular weight on the stoichiometry is also discussed. The isoelectric point of the complexes was found to be directly related to the protonation degree of chitosan. It is clearly demonstrated that the net charge of DNA-chitosan complex can be expressed in terms of the ratio [NH3(+)]/[P(-)], showing that the electrostatic interactions between DNA and chitosan are the main phenomena taking place in the solution. Compaction of DNA long chain complexed with low molar mass chitosan gives nanoparticles with an average radius around 150nm. Stable nanoparticles are obtained for a partial neutralization of phosphate ionic sites (i.e.: [NH3(+)]/[P(-)] fraction between 0.35 and 0.80). PMID:27050113

  15. Improvement of grape and wine phenolic content by foliar application to grapevine of three different elicitors: Methyl jasmonate, chitosan, and yeast extract.

    Science.gov (United States)

    Portu, Javier; López, Rosa; Baroja, Elisa; Santamaría, Pilar; Garde-Cerdán, Teresa

    2016-06-15

    Phenolic compounds play a key role in grape and wine organoleptic properties, being therefore a key parameter in wine quality. Elicitor application constitutes an interesting field of research since it is indirectly involved in the accumulation of phenolic compounds. The aim of this study was to compare the effect of the application of three different elicitors on both grape and wine phenolic content. Methyl jasmonate, chitosan, and a commercial yeast extract were applied to the canopy at veraison and one week later. Results showed that foliar treatments carried out with methyl jasmonate and yeast extract achieved the best results, increasing grape and wine anthocyanin content when compared to the control. Moreover, the application of the yeast elicitor also enhanced grape stilbene content. In contrast, the chitosan treatment did not have a substantial impact on the phenolic compounds. The results of this study indicate that methyl jasmonate and yeast extract applications could be a simple practice to increase grape and wine phenolic content. PMID:26868568

  16. Preparation and characterization of chitosan/nano-hydroxyapatite composite used as bone substitute materials

    Institute of Scientific and Technical Information of China (English)

    Zhang Li; Li Yubao; Zhou Gang; Wu Lan; Mu Yuanhua; Yang Zheng

    2007-01-01

    Chitosan/nano-hydroxyapatite composites with different weight ratios were prepared through a co-precipitation method using Ca(OH)2, H3PO4 and chitosan as starting materials. The properties of these composites were characterized by means of TEM, IR, XRD, TGA, bum-out tests and universal matertial testing machine. The results showed that the HA synthesized here was poorly crystalline carbonated nanometer crystals and dispersed uniformly in chitosan phase and there was no phase-separation between the two phases. The addition of n-HA resulted in a decrease of decomposing temperature of chitosan. Because of the interactions between chitosan and n-HA, the mechanical properties of these composites were improved, and the maximum value of the compressive strength was measured to be about 120MPa corresponding to the chitosan/n-HA composite with a weight ratio of 30/70.

  17. Chitosan in Plant Protection

    Directory of Open Access Journals (Sweden)

    Abdelbasset El Hadrami

    2010-03-01

    Full Text Available Chitin and chitosan are naturally-occurring compounds that have potential in agriculture with regard to controlling plant diseases. These molecules were shown to display toxicity and inhibit fungal growth and development. They were reported to be active against viruses, bacteria and other pests. Fragments from chitin and chitosan are known to have eliciting activities leading to a variety of defense responses in host plants in response to microbial infections, including the accumulation of phytoalexins, pathogen-related (PR proteins and proteinase inhibitors, lignin synthesis, and callose formation. Based on these and other proprieties that help strengthen host plant defenses, interest has been growing in using them in agricultural systems to reduce the negative impact of diseases on yield and quality of crops. This review recapitulates the properties and uses of chitin, chitosan, and their derivatives, and will focus on their applications and mechanisms of action during plant-pathogen interactions.

  18. Synthesis and properties of chitosan/polypeptide bioconjugate composite

    International Nuclear Information System (INIS)

    Adhesive polypeptide containing the key component of mussel adhesive protein was synthesized by ring-opening polymerization, and a hybrid material of the adhesive polypeptide and chitosan was prepared through the solution method. Some strong hydrogen bond interaction existed, but without the chemical bond between chitosan and polypeptide molecular in the composites, which was demonstrated by IR and XRD. Tensile strength and elongation-at-break of the composite increased with the increase of the polypeptide content. However, the mechanical properties decreased when the content of polypeptide was more than 2% in the composite; all in all, the mechanical properties of the composite were better than the pure chitosan. Furthermore, the introduction of polypeptide was beneficial in improving the hydrophilicity and cell affinity of the composite. The results indicated that the novel chitosan/polypeptide composite has excellent biocompatibility, which could be a scaffold material for cell culture in tissue engineering

  19. A review on chitosan-based adsorptive membranes.

    Science.gov (United States)

    Salehi, Ehsan; Daraei, Parisa; Arabi Shamsabadi, Ahmad

    2016-11-01

    Membrane adsorbents have emerged as powerful and attractive tools for the removal of hazardous materials such as dyes and heavy metal ions, mainly in trace amounts, from water resources. Among membrane adsorbents, those prepared from or modified with chitosan biopolymer and its derivatives are cases of interest because of chitosan advantages including biocompatibility, biodegradability, nontoxicity, reactivity, film and fiber forming capacity and favorable hydrophilicity. This review is oriented to provide a framework for better insight into fabrication methods and applications of chitosan-based adsorptive membranes. Critical aspects including thermokinetic analyses of adsorption and regeneration capacity of the membrane adsorbents have been also overviewed. Future of chitosan-based adsorptive membranes might include efforts for the improvement of mechanical stability and reusability and also most targeted application of appropriate copolymers as well as nanostructures in preparing high performance adsorptive membranes. PMID:27516289

  20. Inhibition of Inositol-1-phosphate Synthetase in Mycobacterium Tuberculosis by Chitosan-antisense Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    LI Yuanyuan; CHEN Zhifei; ZHANG Hongling; LI Xiaobo; SHEN Jie; LU Shi; XU Shunqing

    2009-01-01

    Oligodeoxynucleotides (ODNs) were combined with the biodegradable polymer chitosan to form chitosan-ODN nanoparticles by complex coacervation, in order to improve the sta-bility and intracellular penetration. The diameter of the nanoparticles was light strength size and ranged between 60 and 219 nm with a mean value of 132 nm, while zeta potential was between +12 and + 20 mV at pH 5.5. The chitosan-ODN nanoparticles could partially protect the encapsulated ODN from nuclease degradation. Moreover, chitosan-ODN nanoparticles were much more effective in inhibiting the proliferation of M.tuberculosis than free ODN.

  1. Linear and Branched Chitosan Oligomers as Delivery Systems for pDNA and siRNA In Vitro and In Vivo

    OpenAIRE

    Issa, Mohamed Mahmoud

    2006-01-01

    In this thesis, chitosan, a biocompatible polysaccharide that has been approved as a food additive was selected as a platform for the development of safe, efficient non-viral gene delivery systems to mammalian cells. Previously, chitosan-based gene formulations had been generally associated with high molecular weight chitosans, which were poorly characterised in terms of molecular weight distribution and degree of acetylation. Therefore, in order to improve the properties of chitosan-based ge...

  2. Antitumour Acitivty of Chitosan Hydrogen Selenites

    Institute of Scientific and Technical Information of China (English)

    CaiQinQIN; XiaoHaiGAO; 等

    2002-01-01

    Chitosans reacted with selenious acid to prepare chitosan hydrogen selenites, which were found to be growth-inhibitory against sarcoma 180 solid tumor. The results indicated that the activity also depended on the molecular weight of chitosan supports.

  3. Antitumour Activity of Chitosan Hydrogen Selenites

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Chitosans reacted with selenious acid to prepare chitosan hydrogen selenites, which were found to be growth-inhibitory against sarcoma 180 solid tumor. The results indicated that the activity also depended on the molecular weight of chitosan supports.

  4. Low molecular weight chitosan conjugated with folate for siRNA delivery in vitro: optimization studies

    Directory of Open Access Journals (Sweden)

    Shi Q

    2012-11-01

    Full Text Available Julio C Fernandes,1 Xingping Qiu,2 Francoise M Winnik,2 Mohamed Benderdour,1 Xiaoling Zhang,3 Kerong Dai,3 Qin Shi11Orthopaedics Research Laboratory, Research Centre, Sacré-Coeur Hospital, 2Department of Physical Chemistry and Polymer Science, Faculty of Pharmacy, University of Montreal, Montreal, Quebec, Canada; 3Orthopaedic Cellular and Molecular Biology Laboratories, Institute of Health Sciences, Chinese Academy of Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, ChinaAbstract: The low transfection efficiency of chitosan is one of its drawbacks as a gene delivery carrier. Low molecular weight chitosan may help to form small-sized polymer-DNA or small interfering RNA (siRNA complexes. Folate conjugation may improve gene transfection efficiency because of the promoted uptake of folate receptor-bearing cells. In the present study, chitosan was conjugated with folate and investigated for its efficacy as a delivery vector for siRNA in vitro. We demonstrate that the molecular weight of chitosan has a major influence on its biological and physicochemical properties, and very low molecular weight chitosan (below 10 kDa has difficulty in forming stable complexes with siRNA. In this study, chitosan 25 kDa and 50 kDa completely absorbed siRNA and formed nanoparticles (≤220 nm at a chitosan to siRNA weight ratio of 50:1. The introduction of a folate ligand onto chitosan decreased nanoparticle toxicity. Compared with chitosan-siRNA, folate-chitosan-siRNA nanoparticles improved gene silencing transfection efficiency. Therefore, folate-chitosan shows potential as a viable candidate vector for safe and efficient siRNA delivery.Keywords: nonviral vector, chitosan, gene delivery, folate-targeted, siRNA

  5. Isolation and Identification of Indigenous Plant Growth Promoting Rhizobacteria from Himalayan Region of Kashmir and their Effect on Improving Growth and Nutrient Contents of Maize (Zea Mays L.)

    OpenAIRE

    Mahwish eZahid

    2015-01-01

    IIntroduction and exploitation of plant growth promoting rhizobacteria (PGPR) in agro-ecosystems enhance plant-microbes interactions that may affect ecosystems sustainability, agricultural productivity and environmental quality. The present study was conducted to isolate and identify PGPRs associated with maize (Zea mays L.) from twenty sites of Himalayan region of Hajira-Rawalakot, Azad Jammu and Kashmir (AJK), Pakistan. A total of one hundred isolates were isolated from these sites, out of ...

  6. Isolation and identification of indigenous plant growth promoting rhizobacteria from Himalayan region of Kashmir and their effect on improving growth and nutrient contents of maize (Zea mays L.)

    OpenAIRE

    Zahid, Mahwish; Abbasi, M. Kaleem; Hameed, Sohail; Rahim, Nasir

    2015-01-01

    Introduction and exploitation of plant growth promoting rhizobacteria (PGPR) in agro-ecosystems enhance plant–microbes interactions that may affect ecosystems sustainability, agricultural productivity, and environmental quality. The present study was conducted to isolate and identify PGPRs associated with maize (Zea mays L.) from twenty sites of Himalayan region of Hajira-Rawalakot, Azad Jammu and Kashmir (AJK), Pakistan. A total of 100 isolates were isolated from these sites, out of which ei...

  7. Thiolated chitosan nanoparticles: transfection study in the Caco-2 differentiated cell culture

    International Nuclear Information System (INIS)

    The aim of this study was to monitor the expression of secreted protein in differentiated Caco-2 cells after transfection with nanoparticles, in order to improve gene delivery. Based on unmodified chitosan and thiolated chitosan conjugates, nanoparticles with the gene reporter pSEAP (recombinant Secreted Alkaline Phosphatase) were generated at pH 4.0. Transfection studies of thiolated chitosan in Caco-2 cells during the exponential growth phase and differentiation growth phase of the cells led to a 5.0-fold and 2.0-fold increase in protein expression when compared to unmodified chitosan nanoparticles. The mean particle size for both unmodified chitosan and cross-linked thiolated chitosan nanoparticles is 212.2 ± 86 and 113.6 ± 40 nm, respectively. The zeta potential of nanoparticles was determined to be 7.9 ± 0.38 mV for unmodified chitosan nanoparticles and 4.3 ± 0.74 mV for cross-linked thiolated chitosan nanoparticles. Red blood cell lysis evaluation was used to evaluate the membrane damaging properties of unmodified and thiolated chitosan nanoparticles and led to 4.61 ± 0.36% and 2.29 ± 0.25% lysis, respectively. Additionally, cross-linked thiolated chitosan nanoparticles were found to exhibit higher stability toward degradation in gastric juices. Furthermore the reversible effect of thiolated chitosan on barrier properties was monitored by measuring the transepithelial electrical resistance (TEER) and is supported by immunohistochemical staining for the tight junction protein claudin. According to these results cross-linked thiolated chitosan nanoparticles have the potential to be used as a non-viral vector system for gene therapy

  8. Thiolated chitosan nanoparticles: transfection study in the Caco-2 differentiated cell culture

    Science.gov (United States)

    Martien, Ronny; Loretz, Brigitta; Sandbichler, Adolf Michael; Bernkop Schnürch, Andreas

    2008-01-01

    The aim of this study was to monitor the expression of secreted protein in differentiated Caco-2 cells after transfection with nanoparticles, in order to improve gene delivery. Based on unmodified chitosan and thiolated chitosan conjugates, nanoparticles with the gene reporter pSEAP (recombinant Secreted Alkaline Phosphatase) were generated at pH 4.0. Transfection studies of thiolated chitosan in Caco-2 cells during the exponential growth phase and differentiation growth phase of the cells led to a 5.0-fold and 2.0-fold increase in protein expression when compared to unmodified chitosan nanoparticles. The mean particle size for both unmodified chitosan and cross-linked thiolated chitosan nanoparticles is 212.2 ± 86 and 113.6 ± 40 nm, respectively. The zeta potential of nanoparticles was determined to be 7.9 ± 0.38 mV for unmodified chitosan nanoparticles and 4.3 ± 0.74 mV for cross-linked thiolated chitosan nanoparticles. Red blood cell lysis evaluation was used to evaluate the membrane damaging properties of unmodified and thiolated chitosan nanoparticles and led to 4.61 ± 0.36% and 2.29 ± 0.25% lysis, respectively. Additionally, cross-linked thiolated chitosan nanoparticles were found to exhibit higher stability toward degradation in gastric juices. Furthermore the reversible effect of thiolated chitosan on barrier properties was monitored by measuring the transepithelial electrical resistance (TEER) and is supported by immunohistochemical staining for the tight junction protein claudin. According to these results cross-linked thiolated chitosan nanoparticles have the potential to be used as a non-viral vector system for gene therapy.

  9. Mitigation of the Adverse Effects of Salt Stress on Maize (Zea Mays L. Through Organic Amendments

    Directory of Open Access Journals (Sweden)

    Debasish Kumar Das

    2013-12-01

    Full Text Available Salinity is a major limiting factor for crop production in coastal areas of Bangladesh. Organic amendments could contribute to the improvement of crop production in coastal areas. Two maize cultivars (BARI Hybrid Maize-5 and Hybrid Maize Pacific-987 were grown in pots to investigate the mitigating adverse effects of salt stress in maize by organic amendments. Two doses of farmyard manure (FYM and poultry manure (PM were mixed with soils before seed sowing. Plants were subjected to salinity (0-50 mM NaCl at vegetative stage. Salt stress caused a significant reduction in growth and yield of both maize cultivars. Higher NaCl (50 mM stress caused a drastic decrease in growth and yield of both maize cultivars. Salinity also decreased reproductive growth, chlorophyll contents and K+/Na+ ratio in both maize cultivars. Organic amendments with FYM and PM improved salt tolerances of maize that were associated with increased yield components, chlorophyll content and K+/Na+ ratio. Hybrid Maize Pacific-987 grown in low salinity with FYM or PM amendments produced higher yield than control condition. On the contrary, BARI Hybrid Maize-5 conferred tolerance to high salinity, when soils were amended with FYM or PM. Furthermore, organic amendments improved electrical conductivity, exchangeable Na and organic matter status under salinity condition. The present study suggests that organic amendments with FYM or PM confer tolerance to salinity in maize by increasing chlorophyll content and K+/Na+ ratio.

  10. Chitosan and chemically modified chitosan beads for acid dyes sorption

    Institute of Scientific and Technical Information of China (English)

    AZLAN Kamari; WAN SAIME Wan Ngah; LAI KEN Liew

    2009-01-01

    The capabilities of chitosan and chitosan-EGDE (ethylene glycol diglycidyl ether) beads for removing Acid Red 37 (AR 37) and Acid Blue 25 (AB 25) from aqueous solution were examined. Chitosan beads were cross-linked with EGDE to enhance its chemical resistance and mechanical strength. Experiments were performed as a function of pH, agitation period and concentration of AR 37 and AB 25. It was shown that the adsorption capacities of chitosan were comparatively higher than chitosan-EGDE for both acid dyes. This is mainly because cross-linking using EGDE reduces the major adsorption sites -NH3+ on chitosan. Langmuir isotherm model showed best conformity compared to Freundlich and BET. The kinetic experimental data agreed very well to the pseudo second-order kinetic model. The desorption study revealed that after three cycles of adsorption and desorption by NaOH and HCl, both adsorbents retained their promising adsorption abilities. FT-IR analysis proved that the adsorption of acid dyes onto chitosan-based adsorbents was a physical adsorption. Results also showed that chitosan and chitosan-EGDE beads were favourable adsorbers and could be employed as low-cost alternatives for the removal of acid dyes in wastewater treatment.

  11. Physico-chemical/biological properties of tripolyphosphate cross-linked chitosan based nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, Soumi Dey [School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur-721302 (India); Farrugia, Brooke L.; Dargaville, Tim R. [Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Groove, Queensland-4059 (Australia); Dhara, Santanu, E-mail: sdhara@smst.iitkgp.ernet.in [School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur-721302 (India)

    2013-04-01

    In this study, chitosan-PEO blend, prepared in a 15 M acetic acid, was electrospun into nanofibers (∼ 78 nm diameter) with bead free morphology. While investigating physico-chemical parameters of blend solutions, effect of yield stress on chitosan based nanofiber fabrication was clearly evidenced. Architectural stability of nanofiber mat in aqueous medium was achieved by ionotropic cross-linking of chitosan by tripolyphosphate (TPP) ions. The TPP cross-linked nanofiber mat showed swelling up to ∼ 300% in 1 h and ∼ 40% degradation during 30 day study period. 3T3 fibroblast cells showed good attachment, proliferation and viability on TPP treated chitosan based nanofiber mats. The results indicate non-toxic nature of TPP cross-linked chitosan based nanofibers and their potential to be explored as a tissue engineering matrix. - Highlights: ► Chitosan based nanofiber fabrication through electrospinning. ► Roles of solution viscosity and yield stress on spinnability of chitosan evidenced. ► Tripolyphosphate (TPP) cross-linking rendered structural stability to nanofibers. ► TPP cross-linking also improved cellular response on chitosan based nanofibers. ► Thus, chitosan based nanofibers are suitable for tissue engineering application.

  12. Development and Characterization of Novel Films Based on Sulfonamide-Chitosan Derivatives for Potential Wound Dressing.

    Science.gov (United States)

    Dragostin, Oana Maria; Samal, Sangram Keshari; Lupascu, Florentina; Pânzariu, Andreea; Dubruel, Peter; Lupascu, Dan; Tuchilus, Cristina; Vasile, Cornelia; Profire, Lenuta

    2015-01-01

    The objective of this study was to develop new films based on chitosan functionalized with sulfonamide drugs (sulfametoxydiazine, sulfadiazine, sulfadimetho-xine, sulfamethoxazol, sulfamerazine, sulfizoxazol) in order to enhance the biological effects of chitosan. The morphology and physical properties of functionalized chitosan films as well the antioxidant effects of sulfonamide-chitosan derivatives were investigated. The chitosan-derivative films showed a rough surface and hydrophilic properties, which are very important features for their use as a wound dressing. The film based on chitosan-sulfisoxazol (CS-S6) showed the highest swelling ratio (197%) and the highest biodegradation rate (63.04%) in comparison to chitosan film for which the swelling ratio was 190% and biodegradation rate was only 10%. Referring to the antioxidant effects the most active was chitosan-sulfamerazine (CS-S5) which was 8.3 times more active than chitosan related to DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging ability. This compound showed also a good ferric reducing power and improved total antioxidant capacity. PMID:26694354

  13. Effect of chitosan on the formation of acrylamide and hydroxymethylfurfural in model, biscuit and crust systems.

    Science.gov (United States)

    Mogol, Burçe Ataç; Gökmen, Vural

    2016-08-10

    Chitosan has been popular as a natural food preservative due to its antibacterial and antifungal activities. It may be used in thermally processed foods such as bread to delay staling and improve the microbial stability during the shelf-life. However, the thermal process could lead to the formation of harmful compounds in bakery products through chemical reactions, in which chitosan could take part. Therefore, this study aims to investigate the effect of chitosan on the formation of acrylamide and hydroxymethylfurfural (HMF) in different model systems. Addition of acid to the asparagine-glucose model system decreased the initial rate of acrylamide formation to approx. 4-times. The chitosan included model system contained higher acrylamide than the asparagine-glucose-acid model but still lower than the asparagine-glucose model system. The HMF content was decreased in the presence of acid due to acid-catalyzed degradation. Additionally, HMF is a potent carbonyl source and utilized in the Maillard reaction. In biscuit samples, addition of acid or chitosan solution to the dough did not significantly affect the acrylamide formation (p > 0.05), however addition of acid increased the formed HMF. In crust samples, acrylamide formation was decreased by acid, while chitosan showed no additional decrease. No interaction was found between HMF and chitosan. The results suggest that the effect of chitosan should be carefully evaluated apart from the effect of acid, in which chitosan was solubilized. PMID:27406058

  14. Physico-chemical/biological properties of tripolyphosphate cross-linked chitosan based nanofibers

    International Nuclear Information System (INIS)

    In this study, chitosan-PEO blend, prepared in a 15 M acetic acid, was electrospun into nanofibers (∼ 78 nm diameter) with bead free morphology. While investigating physico-chemical parameters of blend solutions, effect of yield stress on chitosan based nanofiber fabrication was clearly evidenced. Architectural stability of nanofiber mat in aqueous medium was achieved by ionotropic cross-linking of chitosan by tripolyphosphate (TPP) ions. The TPP cross-linked nanofiber mat showed swelling up to ∼ 300% in 1 h and ∼ 40% degradation during 30 day study period. 3T3 fibroblast cells showed good attachment, proliferation and viability on TPP treated chitosan based nanofiber mats. The results indicate non-toxic nature of TPP cross-linked chitosan based nanofibers and their potential to be explored as a tissue engineering matrix. - Highlights: ► Chitosan based nanofiber fabrication through electrospinning. ► Roles of solution viscosity and yield stress on spinnability of chitosan evidenced. ► Tripolyphosphate (TPP) cross-linking rendered structural stability to nanofibers. ► TPP cross-linking also improved cellular response on chitosan based nanofibers. ► Thus, chitosan based nanofibers are suitable for tissue engineering application

  15. Conductivity enhancement via chemical modification of chitosan based green polymer electrolyte

    International Nuclear Information System (INIS)

    The potential of carboxymethyl chitosan as a green polymer electrolyte has been explored. Chitosan produced from partial deacetylation of chitin was reacted with monochloroacetic acid to form carboxymethyl chitosan. A green polymer electrolyte based chitosan and carboxymethyl chitosan was prepared by solution-casting technique. The powder and films were characterized by reflection Fourier transform infrared (ATR-FTIR) spectroscopy, 1H nuclear magnetic resonance, elemental analysis and X-ray diffraction, electrochemical impedance spectroscopy, and scanning electron microscopy. The shift of wavenumber that represents hydroxyl and amine stretching confirmed the polymer solvent complex formation. The XRD spectra results show that chemical modification of chitosan has improved amorphous properties of chitosan. The ionic conductivity was found to increase by two magnitudes higher with the chemical modification of chitosan. The highest conductivity achieved was 3.6 × 10−6 S cm−1 for carboxymethyl chitosan at room temperature and 3.7 × 10−4 S cm−1 at 60 °C

  16. Development and Characterization of Novel Films Based on Sulfonamide-Chitosan Derivatives for Potential Wound Dressing

    Directory of Open Access Journals (Sweden)

    Oana Maria Dragostin

    2015-12-01

    Full Text Available The objective of this study was to develop new films based on chitosan functionalized with sulfonamide drugs (sulfametoxydiazine, sulfadiazine, sulfadimetho-xine, sulfamethoxazol, sulfamerazine, sulfizoxazol in order to enhance the biological effects of chitosan. The morphology and physical properties of functionalized chitosan films as well the antioxidant effects of sulfonamide-chitosan derivatives were investigated. The chitosan-derivative films showed a rough surface and hydrophilic properties, which are very important features for their use as a wound dressing. The film based on chitosan-sulfisoxazol (CS-S6 showed the highest swelling ratio (197% and the highest biodegradation rate (63.04% in comparison to chitosan film for which the swelling ratio was 190% and biodegradation rate was only 10%. Referring to the antioxidant effects the most active was chitosan-sulfamerazine (CS-S5 which was 8.3 times more active than chitosan related to DPPH (1,1-diphenyl-2-picrylhydrazyl radical scavenging ability. This compound showed also a good ferric reducing power and improved total antioxidant capacity.

  17. Chitosan: Gels and Interfacial Properties

    Directory of Open Access Journals (Sweden)

    Julie Nilsen-Nygaard

    2015-03-01

    Full Text Available Chitosan is a unique biopolymer in the respect that it is abundant, cationic, low-toxic, non-immunogenic and biodegradable. The relative occurrence of the two monomeric building units (N-acetyl-glucosamine and d-glucosamine is crucial to whether chitosan is predominantly an ampholyte or predominantly a polyelectrolyte at acidic pH-values. The chemical composition is not only crucial to its surface activity properties, but also to whether and why chitosan can undergo a sol–gel transition. This review gives an overview of chitosan hydrogels and their biomedical applications, e.g., in tissue engineering and drug delivery, as well as the chitosan’s surface activity and its role in emulsion formation, stabilization and destabilization. Previously unpublished original data where chitosan acts as an emulsifier and flocculant are presented and discussed, showing that highly-acetylated chitosans can act both as an emulsifier and as a flocculant.

  18. Radiation preservation of maize

    International Nuclear Information System (INIS)

    Radiation preservation of maize was carried out. Radiation doses and sources, shielding materials, packaging materials, chemical radiation effects, biological radiation effects, were discussed. Experimental methods, samples and accessories were also presented. (SMN)

  19. Diversity in global maize germplasm: Characterization and utilization

    Indian Academy of Sciences (India)

    B M Prasanna

    2012-11-01

    Maize (Zea mays L.) is not only of worldwide importance as a food, feed and as a source of diverse industrially important products, but is also a model genetic organism with immense genetic diversity. Although it was first domesticated in Mexico, maize landraces are widely found across the continents. Several studies in Mexico and other countries highlighted the genetic variability in the maize germplasm. Applications of molecular markers, particularly in the last two decades, have led to new insights into the patterns of genetic diversity in maize globally, including landraces as well as wild relatives (especially teosintes) in Latin America, helping in tracking the migration routes of maize from the centers of origin, and understanding the fate of genetic diversity during maize domestication. The genome sequencing of B73 (a highly popular US Corn Belt inbred) and Palomero (a popcorn landrace in Mexico) in the recent years are important landmarks in maize research, with significant implications to our understanding of the maize genome organization and evolution. Next-generation sequencing and high-throughput genotyping platforms promise to further revolutionize our understanding of genetic diversity and for designing strategies to utilize the genomic information for maize improvement. However, the major limiting factor to exploit the genetic diversity in crops like maize is no longer genotyping, but high-throughput and precision phenotyping. There is an urgent need to establish a global phenotyping network for comprehensive and efficient characterization of maize germplasm for an array of target traits, particularly for biotic and abiotic stress tolerance and nutritional quality. ‘Seeds of Discovery’ (SeeD), a novel initiative by CIMMYT with financial support from the Mexican Government for generating international public goods, has initiated intensive exploration of phenotypic and molecular diversity of maize germplasm conserved in the CIMMYT Gene Bank; this

  20. Isolation and identification of indigenous plant growth promoting rhizobacteria from Himalayan region of Kashmir and their effect on improving growth and nutrient contents of maize (Zea mays L.).

    Science.gov (United States)

    Zahid, Mahwish; Abbasi, M Kaleem; Hameed, Sohail; Rahim, Nasir

    2015-01-01

    Introduction and exploitation of plant growth promoting rhizobacteria (PGPR) in agro-ecosystems enhance plant-microbes interactions that may affect ecosystems sustainability, agricultural productivity, and environmental quality. The present study was conducted to isolate and identify PGPRs associated with maize (Zea mays L.) from twenty sites of Himalayan region of Hajira-Rawalakot, Azad Jammu and Kashmir (AJK), Pakistan. A total of 100 isolates were isolated from these sites, out of which eight (HJR1, HJR2, HJR3, HJR4, HJR5, MR6, HJR7, HJR8) were selected in vitro for their plant growth promoting ability (PGPA) including phosphorus solubilization, indole-3-acetic acid (IAA) production and N2 fixation. The 16S rRNA gene sequencing technique was used for molecular identity and authentication. Isolates were then further tested for their effects on growth and nutrient contents of maize (Z. mays L.) under pouch and pot conditions. The 16S rRNA gene sequencing and phylogenetic analysis identified these isolates belong to Pseudomonas and Bacillus genera. The isolates promoted plant growth by solubilizing soil P which ranged between 19.2 and 35.6 μg mL(-1). The isolates HJR1, HJR2, HJR3, and HJR5 showed positive activity in acetylene reduction assay showing their N2-fixation potential. All eight isolates showed the potential to produce IAA in the range of 0.9-5.39 μg mL(-1) and promote plant growth. Results from a subsequent pot experiment indicated PGPRs distinctly increased maize shoot and root length, shoot and root dry weight, root surface area, leaf surface area, shoot and root N and P contents. Among the eight isolates, HR3 showed a marked P-solubilizing activity, plant growth-promoting attributes, and the potential to be developed as a biofertilizers for integrated nutrient management strategies. PMID:25852667

  1. Isolation and Identification of Indigenous Plant Growth Promoting Rhizobacteria from Himalayan Region of Kashmir and their Effect on Improving Growth and Nutrient Contents of Maize (Zea Mays L.

    Directory of Open Access Journals (Sweden)

    Mahwish eZahid

    2015-03-01

    Full Text Available IIntroduction and exploitation of plant growth promoting rhizobacteria (PGPR in agro-ecosystems enhance plant-microbes interactions that may affect ecosystems sustainability, agricultural productivity and environmental quality. The present study was conducted to isolate and identify PGPRs associated with maize (Zea mays L. from twenty sites of Himalayan region of Hajira-Rawalakot, Azad Jammu and Kashmir (AJK, Pakistan. A total of one hundred isolates were isolated from these sites, out of which eight (HJR1, HJR2, HJR3, HJR4, HJR5, MR6, HJR7, HJR8 were selected in vitro for their plant growth promoting ability (PGPA including phosphorus solubilization, indole acetic acid (IAA production and N2 fixation. The 16S rRNA gene sequencing technique was used for molecular identity and authentication. Isolates were then further tested for their effects on growth and nutrient contents of maize (Zea mays L. under pouch and pot conditions. The 16S rRNA gene sequencing and phylogenetic analysis identified these isolates belong to Pseudomonas and Bacillus genera. The isolates promoted plant growth by solubilizing soil P which ranged between 19.2 and 35.6 µgmL−1. The isolates HJR1, HJR2, HJR3 and HJR5 showed positive activity in acetylene reduction assay showing their N2-fixation potential. All eight isolates showed the potential to produce IAA in the range of 0.9−5.39 µgmL−1 and promote plant growth. Results from a subsequent pot experiment indicated PGPRs distinctly increased maize shoot and root length, shoot and root dry weight, root surface area, leaf surface area, shoot and root N and P contents. Among the eight isolates, HR3 showed a marked P-solubilizing activity, plant growth-promoting attributes, and the potential to be developed as a biofertilizers for integrated nutrient management strategies

  2. IMPORTANCE OF MAIZE CROPPING

    OpenAIRE

    Mohammed Dhary Yousif EL-JUBOURI

    2012-01-01

    The Corn, wheat and rice together are the main crops. It is a plant that responds well to chemical and organic fertilization and the irrigation. But compliance is sensitive to optimum sowing time and integrated control of weeds, pests and diseases (2). The maize is the most important plant product, from the point of view commercially and is used primarily as fodder. The maize is an important source of vegetable oil and has many applications in industry, the manufacture of diverse items: cosme...

  3. Effectiveness of silane monomer and gamma radiation on chitosan films and PCL-based composites

    International Nuclear Information System (INIS)

    Chitosan films were prepared by casting from its 1% (w/w) solution. Tensile strength (TS) and tensile modulus (TM) of chitosan films were found to be 30 MPa and 450 MPa, respectively. Silane monomer (3-aminopropyl tri-methoxysilane) (0.25%, w/w) was added into the chitosan solution (1%, w/w) and films were casted. Then films were exposed to gamma radiation (5–25 kGy) and mechanical properties were investigated. It was found that at 10 kGy, the values of TS and TM were improved significantly. Silane grafted chitosan film reinforced poly(caprolactone) (PCL)-based tri-layer composites were prepared by compression molding. Silane improved interfacial adhesion between chitosan and PCL in composites. Surface of the films was investigated by scanning electron microscope (SEM) and found better morphology for silane grafted films.

  4. Modification of mechanical and thermal property of chitosan-starch blend films

    Science.gov (United States)

    Tuhin, Mohammad O.; Rahman, Nazia; Haque, M. E.; Khan, Ruhul A.; Dafader, N. C.; Islam, Rafiqul; Nurnabi, Mohammad; Tonny, Wafa

    2012-10-01

    Chitosan-starch blend films (thickness 0.2 mm) of different composition were prepared by casting and their mechanical properties were studied. To improve the properties of chitosan-starch films, glycerol and mustard oil of different composition were used. Chitosan-starch films, incorporated with glycerol and mustard oil, were further modified with monomer 2-hydroxyethyl methacrylate (HEMA) using gamma radiation. The modified films showed improvement in both tensile strength and elongation at break than the pure chitosan-starch films. Water uptake of the films reduced significantly than the pure chitosan-starch film. Thermo gravimetric analysis (TGA) and dynamic mechanical analysis (DMA) showed that the modified films experience less thermal degradation than the pure films. Scanning electron microscopy (SEM) and FTIR were used to investigate the morphology and molecular interaction of the blend film, respectively.

  5. Improving the osteogenesis of human bone marrow mesenchymal stem cell sheets by microRNA-21-loaded chitosan/hyaluronic acid nanoparticles via reverse transfection

    Directory of Open Access Journals (Sweden)

    Wang Z

    2016-05-01

    Full Text Available Zhongshan Wang,1 Guangsheng Wu,2,3 Mengying Wei,4 Qian Liu,1 Jian Zhou,1 Tian Qin,1 Xiaoke Feng,1 Huan Liu,1 Zhihong Feng,1 Yimin Zhao1 1State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Oral Diseases, Department of Prosthodontics, 2State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Department of Periodontology, School of Stomatology, The Fourth Military Medical University, Xi’an, 3Qingdao First Sanatorium, Jinan Military Region, Qingdao, Shandong Province, 4Department of Biochemistry and Molecular Biology, The Fourth Military Medical University, Xi’an, People’s Republic of China Abstract: Cell sheet engineering has emerged as a novel approach to effectively deliver seeding cells for tissue regeneration, and developing human bone marrow mesenchymal stem cell (hBMMSC sheets with high osteogenic ability is a constant requirement from clinics for faster and higher-quality bone formation. In this work, we fabricated biocompatible and safe chitosan (CS/hyaluronic acid (HA nanoparticles (NPs to deliver microRNA-21 (miR-21, which has been proved to accelerate osteogenesis in hBMMSCs; then, the CS/HA/miR-21 NPs were cross-linked onto the surfaces of culture plates with 0.2% gel solution to fabricate miR-21-functionalized culture plates for reverse transfection. hBMMSC sheets were induced continuously for 14 days using a vitamin C-rich method on the miR-21-functionalized culture plates. For the characterization of CS/HA/miR-21 NPs, the particle size, zeta potential, surface morphology, and gel retardation were sequentially investigated. Then, the biological effects of hBMMSC sheets on the miR-21-functionalized culture plates were evaluated. The assay results demonstrated that the hBMMSC sheets could be successfully induced via the novel

  6. Preparation of Low Molecular Weight Chitosan by Radiation and its Application for Plant Growth Promoter. Chapter 10

    International Nuclear Information System (INIS)

    Chitosan was prepared through the alkaline deacetylation of chitin from shrimp shell waste. Chitosan with a degree of deacetylation of about 70% was produced by hot alkaline deacetylation (DDA) at 90°C for 8 hours or at room temperature deacetylation for 7 days. Through these processes, chitosan with an average molecular weight (Mw) of 141 k Dalton was obtained. Low molecular weight chitosan, Mw 14 k Dalton called “Fitosan” was prepared by irradiating chitosan using gamma rays at a dose of 75 kGy. The results showed that gamma irradiation is an effective method of degrading chitosan by cleavages of glycosidic bond. To improve crop yields and suppress diseases due to virus, bacteria, and fungi, Fitosan was successfully applied to chili, potato, and soybean. Socio-economic impacts of the use of Fitosan on the plants include increased income and improvement of the welfare of farmers. (author)

  7. Adherence of paclitaxel drug in magnetite chitosan nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Escobar Zapata, Edna V.; Martinez Perez, Carlos A.; Rodriguez Gonzalez, Claudia A.; Castro Carmona, Javier S. [Instituto de Ingenieria y Tecnologia, Universidad Autonoma de Ciudad Juarez, Ave. Del Charro 610 norte, Col. Partido Romero, C.P. 32320, Cd. Juarez Chihuahua (Mexico); Quevedo Lopez, Manuel A. [Departamento de Polimeros y Materiales, Universidad de Sonora, Blvd. Luis Encinas y Rosales, Hermosillo, Sonora (Mexico); Garcia-Casillas, Perla E., E-mail: pegarcia@uacj.mx [Instituto de Ingenieria y Tecnologia, Universidad Autonoma de Ciudad Juarez, Ave. Del Charro 610 norte, Col. Partido Romero, C.P. 32320, Cd. Juarez Chihuahua (Mexico)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer Chitosan silica magnetite adsorbs antineoplastic drug. Black-Right-Pointing-Pointer Silica coating improve the drug adherence. - Abstract: Cancer treatment is a big challenge in medicine where chemotherapies and radiotherapies are aggressive and poorly effective having side effects as delirium, fatigue, insomnia, nausea and vomiting which are common problems for cancer patients. For this reason, during the last two decades, many researchers have developed several techniques to improve the current therapies; one of them is the functionalization of magnetic nanoparticles for drug delivery. In this work, magnetic nanoparticles with an average crystallite size 21.8 nm were covered in a core/shell type; magnetite/silica, magnetite/chitosan, and a double shell magnetite/silica/chitosan were developed for attaching an antineoplastic drug. The mechanism for the functionalization of the nanoparticles with a single and double shell was studied with Fourier transformed infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The adherence of an antineoplastic drug, paclitaxel, onto functionalized nanoparticles was analyzed with a UV-Visible spectroscopy at a wavelength of 253 nm. It was found that the adherence of the drug is improved up to 18% when magnetite nanoparticles are coated with a single chitosan shell, and when the nanoparticles are coated with a silica/chitosan shell the adherence increases up to 29%.

  8. Adherence of paclitaxel drug in magnetite chitosan nanoparticles

    International Nuclear Information System (INIS)

    Highlights: ► Chitosan silica magnetite adsorbs antineoplastic drug. ► Silica coating improve the drug adherence. - Abstract: Cancer treatment is a big challenge in medicine where chemotherapies and radiotherapies are aggressive and poorly effective having side effects as delirium, fatigue, insomnia, nausea and vomiting which are common problems for cancer patients. For this reason, during the last two decades, many researchers have developed several techniques to improve the current therapies; one of them is the functionalization of magnetic nanoparticles for drug delivery. In this work, magnetic nanoparticles with an average crystallite size 21.8 nm were covered in a core/shell type; magnetite/silica, magnetite/chitosan, and a double shell magnetite/silica/chitosan were developed for attaching an antineoplastic drug. The mechanism for the functionalization of the nanoparticles with a single and double shell was studied with Fourier transformed infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The adherence of an antineoplastic drug, paclitaxel, onto functionalized nanoparticles was analyzed with a UV–Visible spectroscopy at a wavelength of 253 nm. It was found that the adherence of the drug is improved up to 18% when magnetite nanoparticles are coated with a single chitosan shell, and when the nanoparticles are coated with a silica/chitosan shell the adherence increases up to 29%.

  9. The spacer arm length in cell-penetrating peptides influences chitosan/siRNA nanoparticle delivery for pulmonary inflammation treatment

    Science.gov (United States)

    Jeong, Eun Ju; Choi, Moonhwan; Lee, Jangwook; Rhim, Taiyoun; Lee, Kuen Yong

    2015-11-01

    Although chitosan and its derivatives have been frequently utilized as delivery vehicles for small interfering RNA (siRNA), it is challenging to improve the gene silencing efficiency of chitosan-based nanoparticles. In this study, we hypothesized that controlling the spacer arm length between a cell-penetrating peptide (CPP) and a nanoparticle could be critical to enhancing the cellular uptake as well as the gene silencing efficiency of conventional chitosan/siRNA nanoparticles. A peptide consisting of nine arginine units (R9) was used as a CPP, and the spacer arm length was controlled by varying the number of glycine units between the peptide (R9Gn) and the nanoparticle (n = 0, 4, and 10). Various physicochemical characteristics of R9Gn-chitosan/siRNA nanoparticles were investigated in vitro. Increasing the spacing arm length did not significantly affect the complex formation between R9Gn-chitosan and siRNA. However, R9G10-chitosan was much more effective in delivering genes both in vitro and in vivo compared with non-modified chitosan (without the peptide) and R9-chitosan (without the spacer arm). Chitosan derivatives modified with oligoarginine containing a spacer arm can be considered as potential delivery vehicles for various genes.Although chitosan and its derivatives have been frequently utilized as delivery vehicles for small interfering RNA (siRNA), it is challenging to improve the gene silencing efficiency of chitosan-based nanoparticles. In this study, we hypothesized that controlling the spacer arm length between a cell-penetrating peptide (CPP) and a nanoparticle could be critical to enhancing the cellular uptake as well as the gene silencing efficiency of conventional chitosan/siRNA nanoparticles. A peptide consisting of nine arginine units (R9) was used as a CPP, and the spacer arm length was controlled by varying the number of glycine units between the peptide (R9Gn) and the nanoparticle (n = 0, 4, and 10). Various physicochemical characteristics of

  10. Preparation and Comparison of Chitosan Nanoparticles with Different Degrees of Glutathione Thiolation

    Directory of Open Access Journals (Sweden)

    R Dinarvand

    2011-12-01

    Full Text Available Background: Chitosan has gained considerable attentions as a biocompatible carrier to improve delivery of active agents. Application of this vehicle in the form of nanoparticle could profit advantages of nanotechnology to increase efficacy of active agents. The purpose of this study was to provide detailed information about chitosan-glutathione (Cht-GSHnanoparticles which are gaining popularity because of their high mucoadhesive and extended drug release properties. Methods: Depolymerization of chitosan was carried out using sodium nitrite method.Glutathione was covalently attached to chitosan and the solubility of the resulting conjugates was evaluated. Nanoparticles were prepared by ionic gelation method and then the effect of glutathione immobilization on properties of nanoparticles was investigated. Results: Thiolation efficiency was higher in lower molecular weight chitosan polymers compared to unmodified chitosan nanoparticles. Cht-GSH conjugates of the same molecular weight but with different degrees of thiolation had the same hydrodynamic diameter (995± nm and surface charge (102± mV as unmodified chitosan, but comprised of a denser network structure and lower concentration. Cht-GSH nanoparticles also exhibited greater mucoadhesive strength which was less affected by ionic strength and pH of the environment. Conclusion:Thiolation improves the solubility of chitosan without any significant changes in size and charge of nanoparticles, but affects the nanogel structure.

  11. Improvement of application properties of chitosan-based food packaging films by lavender essential oil%薰衣草精油改善壳聚糖基食品包装膜的应用品质

    Institute of Scientific and Technical Information of China (English)

    张赟彬; 王景文; 李月霞; 王一非; 姜萍萍; 刘笑宇

    2014-01-01

    potential biodegradable material due to its edibility, film-forming capacity, non-toxicity, antibacterial activity, biocompatibility and biodegradability. Traditional chitosan-based composite films are made by the casting-evaporation method. However, inferior waterproof and mechanical properties limit their applications in food package industries. Many researches have been conducted to improve the CS film. Incorporating one or several substancesinto CS film have been widespreadly used. Moreover, acetic acid and chitosan-acetate can be removed from traditionally prepared CS film by alkali leaching, resulting in lower film water-solubility. Lavender essential oil (LEO) can be used as sedative, antispasmodic, antiviral and bacteriostat in industries of perfume, aromatherapy and pharmacy. LEO can also be used as a natural spice in drink, ice cream, candy, bakery and chewing gum. In order to improve the physical and mechanical properties of conventional chitosan-based food packaging films, lavender essential oil/chitosan composite films were made with CS by casting-evaporation-alkali leaching method in this study. The films microstructures were characterized by Fourier transform infrared reflectance spectroscopy (FTIR), X-ray diffraction (XRD). The impacts of LEO content on the thickness, mechanical properties, volatiles content, water contact angle, water solubility and swelling property of films were investigated. The results indicated that the partial functional group’s locations of CS matrix were occupied by the LEO ingredients with reduced vibration intensity of covalent bond of CS. Reduced free hydrogen group could form hydrophilic bonds with water, then resulted in the loss of moisture content of films. Moreover, Chitosan-acetate content increased by incorporating LEO. The thicknesses of all films ranged from (20.60±0.34) μm to (23.35±0.65) μm. There was no linear relationship between the film thickness and LEO concentration. Tensile strength (TS) and elongation at

  12. A New Strategy Based on Smrho Protein Loaded Chitosan Nanoparticles as a Candidate Oral Vaccine against Schistosomiasis

    OpenAIRE

    Oliveira, Carolina R.; Rezende, Cíntia M. F.; Silva, Marina R.; Ana Paula Pêgo; Olga Borges; Alfredo M. Goes

    2012-01-01

    BACKGROUND: Schistosomiasis is one of the most important neglected tropical diseases and an effective control is unlikely in the absence of improved sanitation and vaccination. A new approach of oral vaccination with alginate coated chitosan nanoparticles appears interesting because their great stability and the ease of target accessibility, besides of chitosan and alginate immunostimulatory properties. Here we propose a candidate vaccine based on the combination of chitosan-based nanoparticl...

  13. "Omics" of maize stress response for sustainable food production: opportunities and challenges.

    Science.gov (United States)

    Gong, Fangping; Yang, Le; Tai, Fuju; Hu, Xiuli; Wang, Wei

    2014-12-01

    Maize originated in the highlands of Mexico approximately 8700 years ago and is one of the most commonly grown cereal crops worldwide, followed by wheat and rice. Abiotic stresses (primarily drought, salinity, and high and low temperatures), together with biotic stresses (primarily fungi, viruses, and pests), negatively affect maize growth, development, and eventually production. To understand the response of maize to abiotic and biotic stresses and its mechanism of stress tolerance, high-throughput omics approaches have been used in maize stress studies. Integrated omics approaches are crucial for dissecting the temporal and spatial system-level changes that occur in maize under various stresses. In this comprehensive analysis, we review the primary types of stresses that threaten sustainable maize production; underscore the recent advances in maize stress omics, especially proteomics; and discuss the opportunities, challenges, and future directions of maize stress omics, with a view to sustainable food production. The knowledge gained from studying maize stress omics is instrumental for improving maize to cope with various stresses and to meet the food demands of the exponentially growing global population. Omics systems science offers actionable potential solutions for sustainable food production, and we present maize as a notable case study. PMID:25401749

  14. Chitosan Nanoparticles-Mediated Wild-Type p53 Gene Delivery for Cancer Gene Therapy: Improvement in Pharmaceutical & Biological Properties (Enhance in Loading, Release, Expression and Stability of P53 Plasmid and Induction of Apoptosis in Carcinoma Cell Line

    Directory of Open Access Journals (Sweden)

    Mehrdad Hamidi

    2008-05-01

    Full Text Available Efficient non-viral vectors for gene delivery based on chitosan polymer is dependent on a variety of factors, e.g. loading and lelease capacity, stability in biological system and complex size. This system may have low loading, release and stability capacity. Biodegradable and biocompatible nanoparticles formulated using a chitosan polymer has the potential for sustained and controlled gene delivery. Our hypothesis is that nanoparticles-mediated wild-type p53 gene delivery would result in sustained gene expression, and hence better efficacy with a therapeutic gene. In this study, we have determined the pharmaceutical and biological characterization of Chitosan nanoparticles containing wild-type p53. Nanoparticles containing plasmid were formulated using a microemulsion reverse micellar and ionic gelation techniques. In conclusion, chitosan nanoparticles- p53 complex gene delivery results in sustained and better antiproliferative activity, which could be therapeutically beneficial in cancer treatment.

  15. The fabrication and property of hydrophilic and hydrophobic double functional bionic chitosan film.

    Science.gov (United States)

    Wang, Xiaohong; Xi, Zhen; Liu, Zhongxin; Yang, Liang; Cao, Yang

    2011-11-01

    A new kind of hydrophobic bionic chitosan film was fabricated by simulating the surface structure of lotus leaf. The titanium oxide nanotube array was used as templates. Scanning electron microscopy (SEM) images show that one side of this films have nano-scale rough surface with spherical protrusions alike the surface of lotus leaf. The diameter of the protrusions is about 100 nm, which is equal to diameter of the titanium oxide nanotube. The water contact angle of chitosan films is up to 120 degrees and it is hydrophobic. The other side of the film is flat and the contact angle is 70 degrees. That indicated that the hydrophilism of natural materials is connected with the surface structures. The double functional chitosan films, one side is hydrophilic, the other is hydrophobic, can be made by an easy method. This method is non-toxic and clean. The double functional chitosan film will improve the application of chitosan films in medicine. PMID:22413283

  16. Non-woven nanofiber chitosan/peo membranes obtained by electrospinning

    Directory of Open Access Journals (Sweden)

    M. T. M. Bizarria

    2014-03-01

    Full Text Available The present work focused on the preparation and morphological characterization of chitosan-based nanofiber membranes, aiming at applications in medical and pharmacological areas. Membranes with nanofiber diameters ranging from 50 - 300 nm were prepared from polymer solutions through the electrospinning process. To stabilize the process, it was necessary to use poly(ethylene oxide (PEO, which is a biocompatible synthetic polymer. Pure chitosan solutions, as well as chitosan and PEO solution blends, were characterized by their rheological behavior, conductivity, and surface tension measurements. The electrospun fiber thermal characteristics and crystalline structures were investigated through thermogravimetric analysis (TG and differential scanning calorimetry (DSC. Scanning electron microscopy images (SEM were used for the morphological evaluations of the membranes. The addition of PEO to the chitosan solutions improved their electrical conductivity, surface tension and viscosity, greatly favoring the electrospinning process. Thus, membranes with 80% chitosan could be electrospun.

  17. Water sensitivity, antimicrobial, and physicochemical analyses of edible films based on HPMC and/or chitosan.

    Science.gov (United States)

    Sebti, Issam; Chollet, Emilie; Degraeve, Pascal; Noel, Claude; Peyrol, Eric

    2007-02-01

    Several properties of chitosan films associated or not with hydroxypropylmethylcellulose polymer (HPMC) and HPMC films incorporating or not nisin and/or milk fat were studied. Nisin addition at a level of 250 microg mL-1 and likewise chitosan at 1% (w/v) concentration were efficient for total inhibiting Aspergillus niger and Kocuria rhizophila food deterioration microorganisms. HPMC and chitosan films were transparent, whereas nisin and/or fat incorporation induced a 2-fold lightness parameter increase and, consequently, involved more white films. Measurements of tensile strength, as well as ultimate elongation, showed that chitosan and HPMC initial films were elastic and flexible. High thermal treatments and additive incorporation induced less elastic and more plastic films. Water vapor transmission as far as total water desorption rates suggested that chitosan films were slightly sensitive to water. Water transfer was decreased by films. Regarding its hydrophobic property, the capacity of fat to improve film water barrier was very limited. PMID:17263462

  18. Hexanoyl Chitosan-based Gel Electrolyte for Lithium-ion Cell

    Institute of Scientific and Technical Information of China (English)

    Tan Winie; A.K. Arof

    2005-01-01

    @@ 1Introduction Chitosan is soluble in dilute acid solutions as a result of salt formation by the amino groups with various inorganic and organic acids[1,2]. Due to the reactivity of water and other protic solvents such as methanol and acetic acid with the electrode material in the lithiumbased electrochemicaldevices[3], the insolubility of chitosan in aprotic solvents is inadequate to meet the requirements to be used as the electrolyte materials. In order to improve its solubility in aprotic solvents,acyl modification of chitosan was carried out in the present study.Hexanoyl-chitosan (Fig. 1) that exhibited solubility in THF was prepared by reacting the chitosan with hexanoyl chloride in a mixture of pyridine and THF[4].

  19. Effects of AMF on soil improvement and maize growth in mining area under drought stress%干旱胁迫下AM真菌对矿区土壤改良与玉米生长的影响

    Institute of Scientific and Technical Information of China (English)

    李少朋; 毕银丽; 陈昢圳; 陈书琳; 张延旭; 孔维平; 王瑾

    2013-01-01

    stress condition,with maize and degraded soil as the host plant and matrix,effects of arbuscular mycorrhizal fungi(AMF) on the growth and nutrient absorption of maize and the degraded soil in Shendong mine area were studied.The results showed that the treatment of inoculated AMF significantly increased the biomass and the root colonization rate of maize.Leaf relative water content and leaf color readings significantly higher than the control.The content of P,N,and Ca in shoot and the content of P,K,and Ca in root portion of maize of vaccinated treatments increased significantly.After inoculation with AMF,the phosphorus nutrition for maize was particularly improved.The phosphorus content in aerial parts of corn of inoculation treatments were on average of 0.17g/kg higher than that of non inoculation treatments and in roots were on average of 0.24g/kg.Compared with the control,the content of total glomalin and easily extractable glomalin increased by 36.2% and 33% respectively.The content of organic matter in rhizosphere soil also significantly increased.It indicated that the soil inoculated AMF promoted the mineral nutrient absorption by maize and relieved the negative effect of drought on the growth of maize and raised the content of organic matter in rhizosphere soil,which having important meaning on improvement degraded soil in mining area.Using AMF reclamation is conducive to agricultural production and has important meaning for environmental restoration and ecological restoration in Shendong coal mining subsidence area.

  20. Polycaprolactone foam functionalized with chitosan microparticles - a suitable scaffold for cartilage regeneration.

    Science.gov (United States)

    Filová, E; Jakubcová, B; Danilová, I; KuŽelová Košťáková, E; Jarošíková, T; Chernyavskiy, O; Hejda, J; Handl, M; Beznoska, J; Nečas, A; Rosina, J; Amler, E

    2016-03-14

    For biodegradable porous scaffolds to have a potential application in cartilage regeneration, they should enable cell growth and differentiation and should have adequate mechanical properties. In this study, our aim was to prepare biocompatible scaffolds with improved biomechanical properties. To this end, we have developed foam scaffolds from poly-epsilon-caprolactone (PCL) with incorporated chitosan microparticles. The scaffolds were prepared by a salt leaching technique from either 10 or 15 wt% PCL solutions containing 0, 10 and 20 wt% chitosan microparticles, where the same amount and size of NaCl was used as a porogen in all the cases. PCL scaffolds without and with low amounts of chitosan (0 and 10 wt% chitosan) showed higher DNA content than scaffolds with high amounts of chitosan during a 22-day experiment. 10 wt% PCL with 10 and 20 wt% chitosan showed significantly increased viscoelastic properties compared to 15 wt% PCL scaffolds with 0 and 10 wt% chitosan. Thus, 10 wt% PCL scaffolds with 0 wt% and 10 wt% chitosan are potential scaffolds for cartilage regeneration. PMID:26596314

  1. Chitosan and alginate types of bio-membrane in fuel cell application: An overview

    Science.gov (United States)

    Shaari, N.; Kamarudin, S. K.

    2015-09-01

    The major problems of polymer electrolyte membrane fuel cell technology that need to be highlighted are fuel crossovers (e.g., methanol or hydrogen leaking across fuel cell membranes), CO poisoning, low durability, and high cost. Chitosan and alginate-based biopolymer membranes have recently been used to solve these problems with promising results. Current research in biopolymer membrane materials and systems has focused on the following: 1) the development of novel and efficient biopolymer materials; and 2) increasing the processing capacity of membrane operations. Consequently, chitosan and alginate-based biopolymers seek to enhance fuel cell performance by improving proton conductivity, membrane durability, and reducing fuel crossover and electro-osmotic drag. There are four groups of chitosan-based membranes (categorized according to their reaction and preparation): self-cross-linked and salt-complexed chitosans, chitosan-based polymer blends, chitosan/inorganic filler composites, and chitosan/polymer composites. There are only three alginate-based membranes that have been synthesized for fuel cell application. This work aims to review the state-of-the-art in the growth of chitosan and alginate-based biopolymer membranes for fuel cell applications.

  2. Development of drug-loaded chitosan-vanillin nanoparticles and its cytotoxicity against HT-29 cells.

    Science.gov (United States)

    Li, Pu-Wang; Wang, Guang; Yang, Zi-Ming; Duan, Wei; Peng, Zheng; Kong, Ling-Xue; Wang, Qing-Huang

    2016-01-01

    Chitosan as a natural polysaccharide derived from chitin of arthropods like shrimp and crab, attracts much interest due to its inherent properties, especially for application in biomedical materials. Presently, biodegradable and biocompatible chitosan nanoparticles are attractive for drug delivery. However, some physicochemical characteristics of chitosan nanoparticles still need to be further improved in practice. In this work, chitosan nanoparticles were produced by crosslinking chitosan with 3-methoxy-4-hydroxybenzaldehyde (vanillin) through a Schiff reaction. Chitosan nanoparticles were 200-250 nm in diameter with smooth surface and were negatively charged with a zeta potential of - 17.4 mV in neutral solution. Efficient drug loading and drug encapsulation were achieved using 5-fluorouracil as a model of hydrophilic drug. Drug release from the nanoparticles was constant and controllable. The in vitro cytotoxicity against HT-29 cells and cellular uptake of the chitosan nanoparticles were evaluated by methyl thiazolyl tetrazolium method, confocal laser scanning microscope and flow cytometer, respectively. The results indicate that the chitosan nanoparticles crosslinked with vanillin are a promising vehicle for the delivery of anticancer drugs. PMID:24712731

  3. Effect of radiation-degraded chitosan on growth promotion of flower plant in tissue culture

    Energy Technology Data Exchange (ETDEWEB)

    Luan, Le Quang; Ha, Vo Thi Thu; Hai, Le; Hien, Nguyen Quoc [Vietnam Atomic Energy Commission, Nuclear Research Institute, Dalat (Viet Nam); Nagasawa, Naotsugu; Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2002-03-01

    Radiation is a useful tool for degradation of polysaccharides, such as starch, carrageenan, alginate and chitin/chitosan. The viscosity molecular weight (Mw) of chitosan with 80% degree of deacetylation was reduced to 1.5 x 10{sup 5} by irradiation of 50kGy in solid phase. The solution of 10% of chitosan with Mw ca. 15 x 10{sup 5} was then irradiated at doses ranging 10-250kGy for further degradation and the products were supplemented into cultural media for testing of plant growth promotion effect. The results indicated that irradiated chitosan showed a strong growth-promotion effect on the increase of the length of shoot, the length of root and fresh biomass for flower plants namely Limonium latifolium, Eustoma grandiflorum and Chrysanthemum morifolium in tissue culture. The growth-promotion effect was obtained by the treatments with 50ppm of chitosan irradiated at the doses of 75-100kGy in 10% solution. The suitable concentrations of chitosan irradiated at 100kGy are ca. 100ppm for C. morifolium, 30ppm for E. grandiflorum and 40ppm for L. latifolium. In addition, our study also indicated that the survival ratio of transferred flower plantlets treated with irradiated chitosan was improved after acclimatizing for 30 days in the greenhouse. Accordingly, it is concluded that degraded chitosan obtained by radiation degradation technique is effective as a plant growth promoter as well as irradiated alginate. (author)

  4. Development of Thermosensitive Hydrogels of Chitosan, Sodium and Magnesium Glycerophosphate for Bone Regeneration Applications

    Science.gov (United States)

    Lisková, Jana; Bačaková, Lucie; Skwarczyńska, Agata L.; Musial, Olga; Bliznuk, Vitaliy; De Schamphelaere, Karel; Modrzejewska, Zofia; Douglas, Timothy E.L.

    2015-01-01

    Thermosensitive injectable hydrogels based on chitosan neutralized with sodium beta-glycerophosphate (Na-β-GP) have been studied as biomaterials for drug delivery and tissue regeneration. Magnesium (Mg) has been reported to stimulate adhesion and proliferation of bone forming cells. With the aim of improving the suitability of the aforementioned chitosan hydrogels as materials for bone regeneration, Mg was incorporated by partial substitution of Na-β-GP with magnesium glycerophosphate (Mg-GP). Chitosan/Na-β-GP and chitosan/Na-β-GP/Mg-GP hydrogels were also loaded with the enzyme alkaline phosphatase (ALP) which induces hydrogel mineralization. Hydrogels were characterized physicochemically with respect to mineralizability and gelation kinetics, and biologically with respect to cytocompatibility and cell adhesion. Substitution of Na-β-GP with Mg-GP did not negatively influence mineralizability. Cell biological testing showed that both chitosan/Na-β-GP and chitosan/Na-β-GP/Mg-GP hydrogels were cytocompatible towards MG63 osteoblast-like cells. Hence, chitosan/Na-β-GP/Mg-GP hydrogels can be used as an alternative to chitosan/Na-β-GP hydrogels for bone regeneration applications. However the incorporation of Mg in the hydrogels during hydrogel formation did not bring any appreciable physicochemical or biological benefit. PMID:25859630

  5. Development of Thermosensitive Hydrogels of Chitosan, Sodium and Magnesium Glycerophosphate for Bone Regeneration Applications

    Directory of Open Access Journals (Sweden)

    Jana Lisková

    2015-04-01

    Full Text Available Thermosensitive injectable hydrogels based on chitosan neutralized with sodium beta-glycerophosphate (Na-β-GP have been studied as biomaterials for drug delivery and tissue regeneration. Magnesium (Mg has been reported to stimulate adhesion and proliferation of bone forming cells. With the aim of improving the suitability of the aforementioned chitosan hydrogels as materials for bone regeneration, Mg was incorporated by partial substitution of Na-β-GP with magnesium glycerophosphate (Mg-GP. Chitosan/Na-β-GP and chitosan/Na-β-GP/Mg-GP hydrogels were also loaded with the enzyme alkaline phosphatase (ALP which induces hydrogel mineralization. Hydrogels were characterized physicochemically with respect to mineralizability and gelation kinetics, and biologically with respect to cytocompatibility and cell adhesion. Substitution of Na-β-GP with Mg-GP did not negatively influence mineralizability. Cell biological testing showed that both chitosan/Na-β-GP and chitosan/Na-β-GP/Mg-GP hydrogels were cytocompatible towards MG63 osteoblast-like cells. Hence, chitosan/Na-β-GP/Mg-GP hydrogels can be used as an alternative to chitosan/Na-β-GP hydrogels for bone regeneration applications. However the incorporation of Mg in the hydrogels during hydrogel formation did not bring any appreciable physicochemical or biological benefit.

  6. Functionalization of titanium with chitosan via silanation: evaluation of biological and mechanical performances.

    Directory of Open Access Journals (Sweden)

    Pauline Renoud

    Full Text Available Complications in dentistry and orthopaedic surgery are mainly induced by peri-implant bacterial infections and current implant devices do not prevent such infections. The coating of antibacterial molecules such as chitosan on its surface would give the implant bioactive properties. The major challenge of this type of coating is the attachment of chitosan to a metal substrate. In this study, we propose to investigate the functionalization of titanium with chitosan via a silanation. Firstly, the surface chemistry and mechanical properties of such coating were evaluated. We also verified if the coated chitosan retained its biocompatibility with the peri-implant cells, as well as its antibacterial properties. FTIR and Tof-SIMS analyses confirmed the presence of chitosan on the titanium surface. This coating showed great scratch resistance and was strongly adhesive to the substrate. These mechanical properties were consistent with an implantology application. The Chitosan-coated surfaces showed strong inhibition of Actinomyces naeslundii growth; they nonetheless showed a non significant inhibition against Porphyromonas gingivalis after 32 hours in liquid media. The chitosan-coating also demonstrated good biocompatibility to NIH3T3 fibroblasts. Thus this method of covalent coating provides a biocompatible material with improved bioactive properties. These results proved that covalent coating of chitosan has significant potential in biomedical device implantation.

  7. Functionalization of titanium with chitosan via silanation: evaluation of biological and mechanical performances.

    Science.gov (United States)

    Renoud, Pauline; Toury, Bérangère; Benayoun, Stéphane; Attik, Ghania; Grosgogeat, Brigitte

    2012-01-01

    Complications in dentistry and orthopaedic surgery are mainly induced by peri-implant bacterial infections and current implant devices do not prevent such infections. The coating of antibacterial molecules such as chitosan on its surface would give the implant bioactive properties. The major challenge of this type of coating is the attachment of chitosan to a metal substrate. In this study, we propose to investigate the functionalization of titanium with chitosan via a silanation. Firstly, the surface chemistry and mechanical properties of such coating were evaluated. We also verified if the coated chitosan retained its biocompatibility with the peri-implant cells, as well as its antibacterial properties. FTIR and Tof-SIMS analyses confirmed the presence of chitosan on the titanium surface. This coating showed great scratch resistance and was strongly adhesive to the substrate. These mechanical properties were consistent with an implantology application. The Chitosan-coated surfaces showed strong inhibition of Actinomyces naeslundii growth; they nonetheless showed a non significant inhibition against Porphyromonas gingivalis after 32 hours in liquid media. The chitosan-coating also demonstrated good biocompatibility to NIH3T3 fibroblasts. Thus this method of covalent coating provides a biocompatible material with improved bioactive properties. These results proved that covalent coating of chitosan has significant potential in biomedical device implantation. PMID:22859940

  8. Chitosan and chitosan-based particle systems containing a bioactive fish peptide in the abatement of Escherichia coli related infections in the small intestine

    DEFF Research Database (Denmark)

    Bechstein, Stefanie

    system. Additionally, it should have preventive effects and should also be able to eradicate an already established infection or biofilm. Hence, chitosan appears to be a good choice. Chitosan is a natural polymer that is commonly found in crustacean shells and exhibits antibacterial activity. The effect...... appeared inactive probably due to a high particle stability, suggesting that further modifications and improvements of the systems have to be undertaken. Coated particles were shown to interact with the bacteria sufficiently and the CS coat was able to initiate bacterial aggregation. Furthermore, chitosan...

  9. Potassium leakage and maize seed physiological potential

    OpenAIRE

    Miguel Mariane Victorio de Carvalho; Marcos Filho Julio

    2002-01-01

    Seed production usually requires fast decisions to improve the efficacy of seed handling during harvesting, processing and storage. Seed technologists have focused on the development or improvement of procedures which allow rapid and consistent identification of higher quality seed lots. This research verified the effectiveness of the potassium leachate test on the evaluation of the physiological potential of maize seeds in comparison to recommended seed vigor tests. Five seed lots of the hyb...

  10. A multiplex PCR method of detecting recombinant DNAs from five lines of genetically modified maize.

    Science.gov (United States)

    Matsuoka, T; Kuribara, H; Akiyama, H; Miura, H; Goda, Y; Kusakabe, Y; Isshiki, K; Toyoda, M; Hino, A

    2001-02-01

    Seven lines of genetically modified (GM) maize have been authorized in Japan as foods and feeds imported from the USA. We improved a multiplex PCR method described in the previous report in order to distinguish the five lines of GM maize. Genomic DNA was extracted from GM maize with a silica spin column kit, which could reduce experimental time and improve safety in the laboratory and potentially in the environment. We sequenced recombinant DNA (r-DNA) introduced into GM maize, and re-designed new primer pairs to increase the specificity of PCR to distinguish five lines of GM maize by multiplex PCR. A primer pair for the maize intrinsic zein gene (Ze1) was also designed to confirm the presence of amplifiable maize DNA. The lengths of PCR products using these six primer pairs were different. The Ze1 and the r-DNAs from the five lines of GM maize were qualitatively detected in one tube. The specific PCR bands were distinguishable from each other on the basis of the expected length. The r-DNA could be detected from maize samples containing 0.5% of each of the five lines of GM maize. The sensitivity would be acceptable to secure the verification of non-GMO materials and to monitor the reliability of the labeling system. PMID:11383153

  11. Covalently Bonded Chitosan on Graphene Oxide via Redox Reaction

    Directory of Open Access Journals (Sweden)

    Víctor M. Castaño

    2013-03-01

    Full Text Available Carbon nanostructures have played an important role in creating a new field of materials based on carbon. Chemical modification of carbon nanostructures through grafting has been a successful step to improve dispersion and compatibility in solvents, with biomolecules and polymers to form nanocomposites. In this sense carbohydrates such as chitosan are extremely valuable because their functional groups play an important role in diversifying the applications of carbon nanomaterials. This paper reports the covalent attachment of chitosan onto graphene oxide, taking advantage of this carbohydrate at the nanometric level. Grafting is an innovative route to modify properties of graphene, a two-dimensional nanometric arrangement, which is one of the most novel and promising nanostructures. Chitosan grafting was achieved by redox reaction using different temperature conditions that impact on the morphology and features of graphene oxide sheets. Transmission Electron Microscopy, Fourier Transform Infrared, Raman and Energy Dispersive spectroscopies were used to study the surface of chitosan-grafted-graphene oxide. Results show a successful modification indicated by the functional groups found in the grafted material. Dispersions of chitosan-grafted-graphene oxide samples in water and hexane revealed different behavior due to the chemical groups attached to the graphene oxide sheet.

  12. Chitosan: Gels and Interfacial Properties

    OpenAIRE

    Julie Nilsen-Nygaard; Strand, Sabina P.; Kjell M. Vårum; Kurt I. Draget; Catherine T. Nordgård

    2015-01-01

    Chitosan is a unique biopolymer in the respect that it is abundant, cationic, low-toxic, non-immunogenic and biodegradable. The relative occurrence of the two monomeric building units (N-acetyl-glucosamine and d-glucosamine) is crucial to whether chitosan is predominantly an ampholyte or predominantly a polyelectrolyte at acidic pH-values. The chemical composition is not only crucial to its surface activity properties, but also to whether and why chitosan can undergo a sol–gel transition. T...

  13. Adsorption of hexavalent chromium by graphite–chitosan binary composite

    Indian Academy of Sciences (India)

    RAJENDRA S DONGRE

    2016-06-01

    Graphite chitosan binary (GCB) composite was prepared for hexavalent chromium adsorption from studied water. GCB was characterized by TGA, FTIR, SEM and X-ray diffraction techniques.Wide porous sorptive surface of 3.89 m$^2$ g$^{−1}$ and absorptive functionalities of GCB was due to 20% (w/w) graphite support on chitosan evidenced from FTIR and SEM that impart maximum adsorption at pH 4, agitation with 200 rpm for 180 min. Adsorption studies revealed intraparticle diffusion models and best-fitted kinetics was pseudo 2nd order one. A wellfitted Langmuir isotherm model suggested monolayer adsorption with an adsorption capacity ($q_m$) of 105.6 mg g$^{−1}$ and $R^2 = 0.945$. Sorption mechanisms based on metal ionic interactions, intrusion/diffusion and chemisorptions onto composite. This graphite chitosan binary composite improve sorbent capacity for Cr(VI).

  14. [Konjac glucomannan-collagen -chitosan blend films (I)].

    Science.gov (United States)

    Wang, Bi; Wang, Kunyu; Dan, Weihu; Zhang, Tingyou; Ye, Yong

    2006-02-01

    Konjac glucomannan-collagen-chitosan blend films were prepared successfully by the solvent-casting method and were characterized by FT-IR,X-ray diffraction, SEM and optical transmittance. Moreover, tensile strength, breaking extension, water absorption, water vapor permeation coefficients, adsorbability and penetrating rates were measured. The results indicated that some strong interaction and good compatibility existed among Konjac glucomannan /collagen and chitosan in the blend films. Some properties of the KCCS films were improved markedly in comparison with binary blend films or Konjac glucomannan, collagen and chitosan film. The results of culturing vessel endothelial cells on CKCS-5 film showed that the blend films have good cell compatibility which indicates the potential for a scalfold material in tissue engineering. PMID:16532821

  15. From many, one: genetic control of prolificacy during maize domestication.

    Directory of Open Access Journals (Sweden)

    David M Wills

    2013-06-01

    Full Text Available A reduction in number and an increase in size of inflorescences is a common aspect of plant domestication. When maize was domesticated from teosinte, the number and arrangement of ears changed dramatically. Teosinte has long lateral branches that bear multiple small ears at their nodes and tassels at their tips. Maize has much shorter lateral branches that are tipped by a single large ear with no additional ears at the branch nodes. To investigate the genetic basis of this difference in prolificacy (the number of ears on a plant, we performed a genome-wide QTL scan. A large effect QTL for prolificacy (prol1.1 was detected on the short arm of chromosome 1 in a location that has previously been shown to influence multiple domestication traits. We fine-mapped prol1.1 to a 2.7 kb "causative region" upstream of the grassy tillers1 (gt1 gene, which encodes a homeodomain leucine zipper transcription factor. Tissue in situ hybridizations reveal that the maize allele of prol1.1 is associated with up-regulation of gt1 expression in the nodal plexus. Given that maize does not initiate secondary ear buds, the expression of gt1 in the nodal plexus in maize may suppress their initiation. Population genetic analyses indicate positive selection on the maize allele of prol1.1, causing a partial sweep that fixed the maize allele throughout most of domesticated maize. This work shows how a subtle cis-regulatory change in tissue specific gene expression altered plant architecture in a way that improved the harvestability of maize.

  16. Studies on the effect of brown rice and maize flour on the quality of bread

    OpenAIRE

    M.Z. Islam; M Shams

    2011-01-01

    Breads were prepared with various combinations of maize, brown rice and wheat flours in the basic formulation of bread. The baking properties and chemical composition of bread were evaluated and analysed, respectively. The bread volume decreased, where as bread weight and moisture content increased with the increasing level of maize and brown rice flour. The crumb and crust colour of breads were improved with addition of 8% maize and 8% brown rice flour in bread formulation. The protein conte...

  17. QTL Mapping of Low-Temperature Germination Ability in the Maize IBM Syn4 RIL Population

    OpenAIRE

    Hu, Shuaidong; Lübberstedt, Thomas; Zhao, Guangwu; Lee, Michael

    2016-01-01

    Low temperature is the primary factor to affect maize sowing in early spring. It is, therefore, vital for maize breeding programs to improve tolerance to low temperatures at seed germination stage. However, little is known about maize QTL involved in low-temperature germination ability. 243 lines of the intermated B73×Mo17 (IBM) Syn4 recombinant inbred line (RIL) population was used for QTL analysis of low-temperature germination ability. There were significant differences in germination-rela...

  18. MicroRNA Transcriptomic Analysis of Heterosis during Maize Seed Germination

    OpenAIRE

    Ding, Dong; Wang, Yinju; Han, Mingshui; Fu, Zhiyuan; Li, Weihua; Liu, Zonghua; Hu, Yanmin; Tang, Jihua

    2012-01-01

    Heterosis has been utilized widely in the breeding of maize and other crops, and plays an important role in increasing yield, improving quality and enhancing stresses resistance, but the molecular mechanism responsible for heterosis is far from clear. To illustrate whether miRNA-dependent gene regulation is responsible for heterosis during maize germination, a deep-sequencing technique was applied to germinating embryos of a maize hybrid, Yuyu22, which is cultivated widely in China and its pa...

  19. Preparation and Characterization of Acylated Chitosan

    Institute of Scientific and Technical Information of China (English)

    LI Ming-chun; LIU Chao; XIN Mei-hua; ZHAO Huang; WANG Min; FENG Zhen; SUN Xiao-li

    2005-01-01

    Fully acylated chitosan and N, N-diacyl chitosan were prepared. The products were characterized by elemental analysis, FTIR and 1H NMR. The experimental results indicate that the average degree of acylation depends on the volume ratio of pyridine to chloroform in the reaction medium, the chain length of the acylation agent used, and the molecular weight of chitosan raw materials. The XRD measurements were carried out for pure chitosan, fully acylated chitosan and N, N-diacyl chitosan to verify the crystallinity change caused by the acylation.

  20. Insect Resistant Maize 5307

    OpenAIRE

    Directorate, Issued by Health Canada's Food

    2014-01-01

    Health Canada has notified Syngenta Seeds Canada Inc. that it has no objection to the sale of food derived from Insect Resistant Maize 5307. The Department conducted a comprehensive assessment of this corn event according to its Guidelines for the Safety Assessment of Novel Foods. These Guidelines are based upon internationally accepted principles for establishing the safety of foods with novel traits.

  1. Antibacterial activity of irradiated and non-irradiated chitosan and chitosan derivatives against Escherichia coli growth

    International Nuclear Information System (INIS)

    Samples of chitosan and four chitosan derivatives [ionic chitosan, chitosan lactate, carboxymethyl chitosan (C) and carboxymethyl chitosan (L)] were studied for their antibacterial activities against Escherichia coli growth. Chitosan and chitosan derivatives were prepared at concentrations 20, 100, 1000, 10000 ppm and 250, 1000, 5000, 10000, 20000 ppm, respectively. Each of the samples was tested before and after irradiation with electron beam at 25 kGy. The turbidity of bacterial growth media was measured periodically at 0, 0.5, 1, 2, 4, 6 and 24 h after inoculation using the optical density method. The results indicated that non- irradiated chitosan inhibited E. coli growth at 20 and 100 ppm. Meanwhile, irradiated chitosan at 100 and 1000 ppm concentration inhibited E. coli growth. Both irradiated and non-irradiated ionic chitosan inhibited E. coli growth at all concentrations used. Chitosan lactate was found to inhibit E. coli at concentration as low as 5000 ppm for both irradiated and non-irradiated samples. E. coli growth was not inhibited by carboxymethyl chitosan (C) and carboxymethyl chitosan (L), before and after irradiation. The findings suggested that chitosan has greater antibacterial activity as compared to the chitosan derivative samples. (Author)

  2. Transdermal delivery of propranolol hydrochloride through chitosan nanoparticles dispersed in mucoadhesive gel.

    Science.gov (United States)

    Al-Kassas, Raida; Wen, Jingyuan; Cheng, Angel En-Miao; Kim, Amy Moon-Jung; Liu, Stephanie Sze Mei; Yu, Joohee

    2016-11-20

    This study aimed at improving the systemic bioavailability of propranolol-HCl by the design of transdermal drug delivery system based on chitosan nanoparticles dispersed into gels. Chitosan nanoparticles were prepared by ionic gelation technique using tripolyphosphate (TPP) as a cross-linking agent. Characterization of the nanoparticles was focused on particle size, zeta potential, surface texture and morphology, and drug encapsulation efficiency. The prepared freeze dried chitosan nanoparticles were dispersed into gels made of poloxamer and carbopol and the rheological behaviour and the adhesiveness of the gels were investigated. The results showed that smallest propranolol loaded chitosan nanoparticles were achieved with 0.2% chitosan and 0.05% TPP. Nanoparticles were stable in suspension with a zeta potential (ZP) above ±30mV to prevent aggregation of the colloid. Zeta potential was found to increase with increasing chitosan concentration due to its cationic nature. At least 70% of entrapment efficiency and drug loading were achieved for all prepared nanoparticles. When chitosan nanoparticles dispersed into gel consisting of poloxamer and carbopol, the resultant formulation exhibited thixotropic behaviour with a prolonged drug release properties as shown by the permeation studies through pig ear skin. Our study demonstrated that the designed nanoparticles-gel transdermal delivery system has a potential to improve the systemic bioavailability and the therapeutic efficacy of propranolol-HCl. PMID:27561485

  3. Radiation synthesis of chitosan beads grafted with acrylic acid for metal ions sorption

    Energy Technology Data Exchange (ETDEWEB)

    Benamer, S., E-mail: benamers@yahoo.fr [Division of Nuclear Applications, Centre de Recherche Nucleaire d' Alger, BP-399 Alger-Gare (Algeria); Mahlous, M.; Tahtat, D.; Nacer-Khodja, A.; Arabi, M. [Division of Nuclear Applications, Centre de Recherche Nucleaire d' Alger, BP-399 Alger-Gare (Algeria); Lounici, H.; Mameri, N. [Ecole Nationale Polytechnique d' El-Harrach Alger (Algeria)

    2011-12-15

    Radiation-induced grafting of acrylic acid onto chitosan beads was performed in solution at a dose rate of 20.6 Gy/min of cobalt-60 gamma rays. The effect of absorbed dose on grafting yield was investigated. The characterization of the grafted material was performed by FTIR spectroscopy and the swelling measurements at different pHs. The grafting yield increased with the increase in dose, it reached 80% at 40 kGy irradiation dose. The removal of Pb and Cd ions from aqueous solutions was investigated with both ungrafted and grafted chitosan beads. The sorption behavior of the sorbents was examined through pH, kinetics and equilibrium measurements. Grafted chitosan beads presented higher sorption capacity for both metal ions than unmodified chitosan beads. - Highlights: > Pb and Cd ions are removed from aqueous solution by adsorption on chitosan beads. > Crosslinking process improves chemical stability of chitosan beads. > Radiation grafting of acrylic acid onto chitosan improves its metal adsorption capacity. > Increase in grafting degree enhances the adsorption capacity of the material. > Gamma radiation is a powerful tool for an accurate control of the grafting yield.

  4. Radiation synthesis of chitosan beads grafted with acrylic acid for metal ions sorption

    International Nuclear Information System (INIS)

    Radiation-induced grafting of acrylic acid onto chitosan beads was performed in solution at a dose rate of 20.6 Gy/min of cobalt-60 gamma rays. The effect of absorbed dose on grafting yield was investigated. The characterization of the grafted material was performed by FTIR spectroscopy and the swelling measurements at different pHs. The grafting yield increased with the increase in dose, it reached 80% at 40 kGy irradiation dose. The removal of Pb and Cd ions from aqueous solutions was investigated with both ungrafted and grafted chitosan beads. The sorption behavior of the sorbents was examined through pH, kinetics and equilibrium measurements. Grafted chitosan beads presented higher sorption capacity for both metal ions than unmodified chitosan beads. - Highlights: → Pb and Cd ions are removed from aqueous solution by adsorption on chitosan beads. → Crosslinking process improves chemical stability of chitosan beads. → Radiation grafting of acrylic acid onto chitosan improves its metal adsorption capacity. → Increase in grafting degree enhances the adsorption capacity of the material. → Gamma radiation is a powerful tool for an accurate control of the grafting yield.

  5. Chitosan, a new and environmental benign electrode binder for use with graphite anode in lithium-ion batteries

    International Nuclear Information System (INIS)

    Highlights: • Chitosan is used as a new electrode binder for graphite anode. • Electrochemical properties of the chitosan-based electrode are compared with that of PVDF-based one. • Electrochemical performances of the graphite anode are improved by using chitosan binder. • Chitosan binder facilitates the formation of a thin, homogenous and stable SEI film of the electrode. -- Abstract: Chitosan was applied as the electrode binder material for a spherical graphite anode in lithium-ion batteries. Compared to using poly (vinylidene fluoride) (PVDF) binder, the graphite anode using chitosan exhibited enhanced electrochemical performances in terms of the first Columbic efficiency, rate capability and cycling behavior. With similar specific capacity, the first Columbic efficiency of the chitosan-based anode is 95.4% compared to 89.3% of the PVDF-based anode. After 200 charge–discharge cycles at 0.5C, the capacity retention of the chitosan-based electrode showed to be significantly higher than that of the PVDF-based electrode. Electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM) measurements were carried out to investigate the formation and evolution of the solid electrolyte interphase (SEI) formed on the graphite electrodes. The results show that a thin, homogenous and stable SEI layer is formed on the graphite electrode surface with chitosan binder compared with that using the conventional PVDF binder

  6. The Effect of Chitosan and Sodium Alginate on the Growth and Photosynthesis of Soybean

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Seeu coating can make soybean seedling grow more strongly and reinforce the resistance of soybean plant. Sodium alginate and chitosan are high-molecular compound of two different kind,have the characteristic of promoting the crop growth. Using Sodium alginate and chitosan as coating materials under different concentration can improve the growth and photosynthesis obviously and can decrease pollution because of their characteristics. The analysis show that the effects of Sodium Alginate on soybean plant are better than chitosan and the best concentration is 0.50 g @ kg-1

  7. Evaluation of Osseointegration Ability of Porous Polyethylene Implant (Medpor) Treated with Chitosan

    OpenAIRE

    Kwang Kim; Byung-Hoon Kim; Seunggon Jung; Hong-Ju Park; Seung-Ho Ohk; Hee-Kyun Oh; Min-Suk Kook

    2014-01-01

    Purpose. We suggest a successful and simple Medpor treated way with chitosan and evaluate more improved osseointegration ability of it than the orignal. Materials and Methods. Medpor was punched into circular shape and dipped into the chitosan gel solution. The Medpor plates soaked with chitosan were identified by the SEM images. We evaluated the growth rate of MC3T3-E1 cell using Von Kossa staining and MTT assay as in vitro experiment. And we implanted both Medpor plates into skull of domest...

  8. Borate cross-linked graphene oxide-chitosan as robust and high gas barrier films

    Science.gov (United States)

    Yan, Ning; Capezzuto, Filomena; Lavorgna, Marino; Buonocore, Giovanna G.; Tescione, Fabiana; Xia, Hesheng; Ambrosio, Luigi

    2016-05-01

    Chitosan (CS) is one of the most promising polymers due to its biocompatibility, biodegradability, and natural abundance. However, its poor mechanical and barrier properties make it difficult to satisfy a wide range of applications. Herein, borate ions, originating from the hydrolysis of sodium tetraborate decahydrate (borax), have been used to crosslink chitosan and graphene oxide (GO) nanocomposites. Chitosan films consisting of 1.0 wt% boron and 1.0 wt% GO exhibit a significant improvement in both the toughness and oxygen barrier properties compared to pristine chitosan. In particular the tensile strength of the samples after thermal treatment increases by ~160% compared to pristine chitosan, whereas their oxygen permeability reduces by ~90%. This is ascribed to the chemical crosslinking between chitosan and GO nanoplatelets through borate ions, as well as the formation of a layered morphology with graphene nanoplatelets oriented parallel to the sample surface. The exceptional robust and high gas barrier film has promising application in the packaging industry. The borate-crosslinking chemistry represents the potential strategy for improving properties of other polymer nanocomposites.Chitosan (CS) is one of the most promising polymers due to its biocompatibility, biodegradability, and natural abundance. However, its poor mechanical and barrier properties make it difficult to satisfy a wide range of applications. Herein, borate ions, originating from the hydrolysis of sodium tetraborate decahydrate (borax), have been used to crosslink chitosan and graphene oxide (GO) nanocomposites. Chitosan films consisting of 1.0 wt% boron and 1.0 wt% GO exhibit a significant improvement in both the toughness and oxygen barrier properties compared to pristine chitosan. In particular the tensile strength of the samples after thermal treatment increases by ~160% compared to pristine chitosan, whereas their oxygen permeability reduces by ~90%. This is ascribed to the chemical

  9. Cellular compatibility of RGD-modified chitosan nanofibers with aligned or random orientation

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yanyan; Lue Lanxin; Feng Zhangqi; Xiao Zhongdang; Huang Ningping, E-mail: nphuang@seu.edu.c, E-mail: zdxiao@seu.edu.c [State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096 (China)

    2010-10-01

    Aligned and randomly oriented chitosan nanofibers were prepared by electrospinning. The fibers were modified with the RGD cell-adhesive peptide through a heterobifunctional crosslinker containing a segment of poly(ethylene glycol) (PEG). PEG rendered the surface hydrophilic and provided flexible spacers, allowing the preservation of the bioactivity of further captured RGD peptides. NIH 3T3 cells were used to test the cellular compatibility of these chitosan nanofibrous scaffolds. Cell morphology and viability were investigated by SEM, fluorescent staining and cell counting. The results indicate that RGD-modified surfaces significantly improve the cellular compatibility of chitosan nanofibers and suggest a good candidate as a scaffold employed in tissue engineering.

  10. Curcumin-Loaded Chitosan/Gelatin Composite Sponge for Wound Healing Application

    Directory of Open Access Journals (Sweden)

    Van Cuong Nguyen

    2013-01-01

    Full Text Available Three composite sponges were made with 10% of curcumin and by using polymers, namely, chitosan and gelatin with various ratios. The chemical structure and morphology were evaluated by FTIR and SEM. These sponges were evaluated for water absorption capacity, antibacterial activity, in vitro drug release, and in vivo wound healing studies by excision wound model using rabbits. The in vivo study presented a greater wound closure in wounds treated with curcumin-composite sponge than those with composite sponge without curcumin and untreated group. These obtained results showed that combination of curcumin, chitosan and gelatin could improve the wound healing activity in comparison to chitosan, and gelatin without curcumin.

  11. Ascorbyl palmitate-loaded chitosan nanoparticles: characteristic and polyphenol oxidase inhibitory activity.

    Science.gov (United States)

    Kim, Mi Kyung; Lee, Ji-Soo; Kim, Kwang Yup; Lee, Hyeon Gyu

    2013-03-01

    The aim of this study was to produce ascorbyl palmitate (AP)-loaded nanoparticles in order to inhibit polyphenol oxidase (PPO) in bananas. AP-loaded chitosan nanoparticles were prepared using acetic acid and citric acid (denoted as CS/AA and CS/CA nanoparticles, respectively). As the initial AP concentration increases, the particle size significantly decreases, and the zeta potential, entrapment and loading efficiency significantly increases. The PPO inhibitory activity of AP was effectively improved when AP was nano-encapsulated by chitosan compared to no encapsulation. These results suggest that chitosan nano-encapsulation can be used to enhance the PPO inhibitory activity of AP. PMID:23247266

  12. Root gravitropism in maize and Arabidopsis

    Science.gov (United States)

    Evans, Michael L.

    1993-01-01

    Research during the period 1 March 1992 to 30 November 1993 focused on improvements in a video digitizer system designed to automate the recording of surface extension in plants responding to gravistimulation. The improvements included modification of software to allow detailed analysis of localized extension patterns in roots of Arabidopsis. We used the system to analyze the role of the postmitotic isodiametric growth zone (a region between the meristem and the elongation zone) in the response of maize roots to auxin, calcium, touch and gravity. We also used the system to analyze short-term auxin and gravitropic responses in mutants of Arabidopsis with reduced auxin sensitivity. In a related project, we studied the relationship between growth rate and surface electrical currents in roots by examining the effects of gravity and thigmostimulation on surface potentials in maize roots.

  13. Chitosan and lactic acid-grafted chitosan nanoparticles as carriers for prolonged drug delivery

    OpenAIRE

    Bhattarai, Narayan; Ramay, Hassna R; Chou, Shinn-Huey; Zhang, Miqin

    2006-01-01

    Nanoparticles of ~10 nm in diameter made with chitosan or lactic acid-grafted chitosan were developed for high drug loading and prolonged drug release. A drug encapsulation efficiency of 92% and a release rate of 28% from chitosan nanoparticles over a 4-week period were demonstrated with bovine serum protein. To further increase drug encapsulation, prolong drug release, and increase chitosan solubility in solution of neutral pH, chitosan was modified with lactic acid by grafting D,L-lactic ac...

  14. Modeling and optimization of degree of folate grafted on chitosan and carboxymethyl-chitosan

    OpenAIRE

    Esfandiarpour-Boroujeni, S.; Bagheri-Khoulenjani, S.; Mirzadeh, H.

    2015-01-01

    Chitosan is a cationic polysaccharide with great properties and so is considered as an attractive biopolymer. However, chitosan shows its antibacterial activity only in acidic environment and this restricts its uses. So water-soluble chitosan derivatives such as carboxymethyl chitosan could be good candidates for such biomedical applications. Modified chitosan with hydrophobic functional groups such as folate (FA) is able to make self-assembled nanoparticles in aqueous media. One of the most ...

  15. SEM-EDX STUDIES OF CHITOSAN DERIVATIVES-METAL ADDUCTS

    OpenAIRE

    Galo Cárdenas; Edelio Taboada; Armando Bravo; S. Patricia Miranda

    2003-01-01

    Chitosan was obtained from shrimps shells (pleuroncodes monodon) using chemical methods. A series of chitosan (QS)charged with solution of copper, cobalt, nickel and mercury ions were prepared at room temperature using the batch method. N-3,5-diethylamino benzoyl chitosan (QDAB); N,O-dimercapto succinate chitosan (QNOT) and 4-aminobenzoate chitosan (QAB) derivatives were prepared. The chitosan metal adducts with Cu, Co, Ni and Hg ions and derivatives maximum loading is discussed. Chitosan and...

  16. Synthesis and evaluation of PEG-O-chitosan nanoparticles for delivery of poor water soluble drugs: Ibuprofen

    Energy Technology Data Exchange (ETDEWEB)

    Hassani Najafabadi, Alireza [Department of Chemistry, Amirkabir University of Technology, P.O. Box 1587-4413, Tehran (Iran, Islamic Republic of); Abdouss, Majid, E-mail: phdabdouss44@aut.ac.ir [Department of Chemistry, Amirkabir University of Technology, P.O. Box 1587-4413, Tehran (Iran, Islamic Republic of); Faghihi, Shahab [Tissue Engineering and Biomaterials Division, National Institute of Genetic Engineering and Biotechnology, Tehran 14965/161 (Iran, Islamic Republic of)

    2014-08-01

    Current methods for preparation of PEGylated chitosan have limitations such as harsh de protecting step and several purification cycles. In the present study, a facile new method for conjugating methoxy polyethylene glycol (mPEG) to chitosan under mild condition is introduced to improve water solubility of chitosan and control the release of poor water soluble drugs. The method consists of chitosan modification by grafting the C6 position of chitosan to mPEG which is confirmed by Fourier transformed-infrared (FT-IR) and proton nuclear magnetic resonance ({sup 1}HNMR) analyses. The amine groups at the C2 position of chitosan are protected using sodium dodecylsulfate (SDS) which is removed by dialyzing the precipitation against Tris solution. The chemical structure of the prepared polymer is characterized by FTIR and {sup 1}HNMR. The synthesized polymer is then employed to prepare nanoparticles which are characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), scanning electron microscopy (SEM), and dynamic light scattering (DLS) for their size and morphology. The nanoparticles are used for encapsulation of ibuprofen followed by in vitro release investigation in gastrointestinal and simulated biological fluids. The chitosan nanoparticles are used as control. The PEGylated nanoparticles show a particle size of 80 nm with spherical morphology. The results clearly show that drug release from PEGylated chitosan nanoparticles is remarkably slower than chitosan. In addition, drug encapsulation and encapsulation efficiency in PEGylated nanoparticles are dependent on the amount of drug added to the formulation being significantly higher than chitosan nanoparticles. This study provides an efficient, novel, and facile method for preparing a nano carrier system for delivery of water insoluble drugs. - Highlights: • A facile novel method for conjugating methoxy polyethylene glycol (mPEG) to chitosan is introduced. • Fabricated PEG

  17. Synthesis and evaluation of PEG-O-chitosan nanoparticles for delivery of poor water soluble drugs: Ibuprofen

    International Nuclear Information System (INIS)

    Current methods for preparation of PEGylated chitosan have limitations such as harsh de protecting step and several purification cycles. In the present study, a facile new method for conjugating methoxy polyethylene glycol (mPEG) to chitosan under mild condition is introduced to improve water solubility of chitosan and control the release of poor water soluble drugs. The method consists of chitosan modification by grafting the C6 position of chitosan to mPEG which is confirmed by Fourier transformed-infrared (FT-IR) and proton nuclear magnetic resonance (1HNMR) analyses. The amine groups at the C2 position of chitosan are protected using sodium dodecylsulfate (SDS) which is removed by dialyzing the precipitation against Tris solution. The chemical structure of the prepared polymer is characterized by FTIR and 1HNMR. The synthesized polymer is then employed to prepare nanoparticles which are characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), scanning electron microscopy (SEM), and dynamic light scattering (DLS) for their size and morphology. The nanoparticles are used for encapsulation of ibuprofen followed by in vitro release investigation in gastrointestinal and simulated biological fluids. The chitosan nanoparticles are used as control. The PEGylated nanoparticles show a particle size of 80 nm with spherical morphology. The results clearly show that drug release from PEGylated chitosan nanoparticles is remarkably slower than chitosan. In addition, drug encapsulation and encapsulation efficiency in PEGylated nanoparticles are dependent on the amount of drug added to the formulation being significantly higher than chitosan nanoparticles. This study provides an efficient, novel, and facile method for preparing a nano carrier system for delivery of water insoluble drugs. - Highlights: • A facile novel method for conjugating methoxy polyethylene glycol (mPEG) to chitosan is introduced. • Fabricated PEG-grafted chitosan

  18. Biocompatibility of chitosan/Mimosa tenuiflora scaffolds for tissue engineering

    International Nuclear Information System (INIS)

    Highlights: • The porosity of the composites allow biological processes for the cell adaptation on the scaffolds. • The composites improve the viability and proliferation of cells. • Composition of the scaffold plays an important role in the biocompatibility. • The results indicate that Mimosa Tenuiflora can induce the differentiation of osteoblast cells. - Abstract: In search of a plant that exhibits osteogenic activity, Mimosa tenuiflora (M. tenuiflora) cortex represents the opportunity to create a biomaterial that, together with the chitosan, is osteoconductive and promote better and rapid regeneration of bone tissue. Thus, the composite of chitosan/M. tenuiflora cortex fabricated will have properties of biocompatibility and allow the osteoblast proliferation. Composites were developed with different concentrations of chitosan/M. tenuiflora cortex (w/w) using thermally induced phase separation technique (TIPS). To analyze the effects of composite on osteoblasts, primary cultures, each sample was collected on days 1, 3 and 7 after seeding. The evaluation of composites consisted of viability and proliferation tests in which we observed the metabolic activity of the cells using MTT reagent and determined the DNA concentration by means of fluorescence. The expression of the marker alkaline phosphatase (ALP) using p-nitrophenyl phosphate was examined, allowing the observation to the activity of proliferation and differentiation of osteoblastic cells. Moreover, an analysis of biomineralization was performed using scanning electron microscopy (SEM), energy dispersive spectroscopy, infrared spectroscopy and X-ray diffraction. The results showed that 80/20 chitosan/M. tenuiflora cortex biocomposite has the best performance with osteoblasts compared to biomaterials 100/0 and 70/30 chitosan/M. tenuiflora composites. Finally, it was determined that the composite of chitosan/M. tenuiflora cortex presents no cytotoxicity and increases the capacity of the osteoblasts

  19. Biocompatibility of chitosan/Mimosa tenuiflora scaffolds for tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Martel-Estrada, Santos Adriana [Instituto de arquitectura diseño y arte, Universidad Autónoma de Ciudad Juárez, Ave. Del Charro #610 norte, Col. Partido Romero, C.P. 32320 Cd. Juárez, Chihuahua (Mexico); Rodríguez-Espinoza, Brenda [Instituto de Ciencias Biomédicas, Universidad Autónoma de Ciudad Juárez, Anillo envolvente del PRONAF y Estocolmo, C.P. 32320 Cd. Juárez, Chihuahua (Mexico); Santos-Rodríguez, Elí [ICTP Meso-American Centre for Theoretical Physics (ICTP-MCTP)/Universidad Autónoma de Chiapas, Ciudad Universitaria, Carretera Zapata Km. 4, Real del Bosque (Terán), C.P. 29040 Tuxtla Gutiérrez, Chiapas (Mexico); Jiménez-Vega, Florinda [Instituto de Ciencias Biomédicas, Universidad Autónoma de Ciudad Juárez, Anillo envolvente del PRONAF y Estocolmo, C.P. 32320 Cd. Juárez, Chihuahua (Mexico); García-Casillas, Perla E.; Martínez-Pérez, Carlos A. [Instituto de Ingeniería y Tecnología, Universidad Autónoma de Ciudad Juárez, Ave. Del Charro #610 norte, Col. Partido Romero, C.P. 32320 Cd. Juárez, Chihuahua (Mexico); and others

    2015-09-15

    Highlights: • The porosity of the composites allow biological processes for the cell adaptation on the scaffolds. • The composites improve the viability and proliferation of cells. • Composition of the scaffold plays an important role in the biocompatibility. • The results indicate that Mimosa Tenuiflora can induce the differentiation of osteoblast cells. - Abstract: In search of a plant that exhibits osteogenic activity, Mimosa tenuiflora (M. tenuiflora) cortex represents the opportunity to create a biomaterial that, together with the chitosan, is osteoconductive and promote better and rapid regeneration of bone tissue. Thus, the composite of chitosan/M. tenuiflora cortex fabricated will have properties of biocompatibility and allow the osteoblast proliferation. Composites were developed with different concentrations of chitosan/M. tenuiflora cortex (w/w) using thermally induced phase separation technique (TIPS). To analyze the effects of composite on osteoblasts, primary cultures, each sample was collected on days 1, 3 and 7 after seeding. The evaluation of composites consisted of viability and proliferation tests in which we observed the metabolic activity of the cells using MTT reagent and determined the DNA concentration by means of fluorescence. The expression of the marker alkaline phosphatase (ALP) using p-nitrophenyl phosphate was examined, allowing the observation to the activity of proliferation and differentiation of osteoblastic cells. Moreover, an analysis of biomineralization was performed using scanning electron microscopy (SEM), energy dispersive spectroscopy, infrared spectroscopy and X-ray diffraction. The results showed that 80/20 chitosan/M. tenuiflora cortex biocomposite has the best performance with osteoblasts compared to biomaterials 100/0 and 70/30 chitosan/M. tenuiflora composites. Finally, it was determined that the composite of chitosan/M. tenuiflora cortex presents no cytotoxicity and increases the capacity of the osteoblasts

  20. Beta dosimetry in intraperitoneal administration of 166Ho-chitosan

    International Nuclear Information System (INIS)

    Chitosan, a natural biodegradable polymer, was labeled with 166Ho and was administered intraperitoneally in ovarian cancer patients by diffuse intraperitoneal spread. More than 30% of administered 166Ho-chitosan complex was observed to be bound to the peritoneal surface. For the peritoneal dosimetry, all radiation emitted from 166Ho either bound to the peritoneal surface or in the peritoneal fluid should be considered. The volume of ascites is measured by dividing the 166Tc-HSA injected dose by 99mTc-HSA concentration in the ascites. The fraction of 166Ho-chitosan bound to the peritoneal surface is obtained in an indirect method by subtracting the activity in the ascites of known volume from the total adminstered activity and dividing it by standard surface area. This method has been demonstrated by applying the procedure to rats and comparing the results with the actual counts of activity concentration both on the peritoneal surface ad in the intraperitoneal fluid. For rats, about 70% of 166Ho-chitosan injected was found to attach to the peritoneal surface. With 1 mCi of 166Ho-chitosan injection, the activity was 1.3 μCi/cm2 and 2.4 μCi/ml on the peritoneal surface and in the ascites, respectively. For this specific case, the peritoneal surface dose was 105 Gy from 166Ho on the peritoneal surface and 17.8 Gy from 166Ho in the ascites. Dose estimation was performed by Monte Carlo simulation using the EGS4 code. More realistic dose estimation by applying this procedure to patients can help improve the treatment planning of ovarian cancer with 166Ho-chitosan complex

  1. FERROFERRIC OXIDE/CHITOSAN SCAFFOLDS WITH THREE-DIMENSIONAL ORIENTED STRUCTURE

    Institute of Scientific and Technical Information of China (English)

    Jia-han Ke; Zheng-ke Wang; Yin-zhe Li; Qiao-ling Hu; Jie Feng

    2012-01-01

    A facile approach to construct ferroferric oxide/chitosan composite scaffolds with three-dimensional oriented structure has been explored in this research.Chitosan and ferroferric oxide are co-precipitated by using an in situ precipitation method,and then lyophilized to get the composite scaffolds.XRD indicated that Fe3O4 was generated during the gel formation process,and increasing the content of magnetic particles could destruct the crystal structure of chitosan.When the content of magnetic particles is lower than 10%,the layer-by-layer structure and wheel spoke structure are coexisting in the scaffolds.Increasing the content of magnetic particles,just layer-by-layer structure could be observed in the scaffolds.Ferroferric oxide particles were uniformly distributed in the matrix,the size of which was about 0.48 μm in diameter,2 μm in length.Porosity of magnetic chitosan composite scaffolds is about 90%.When the ratio of ferroferric oxide to chitosan is 5/100,the compressive strength of the material is 0.4367 MPa,which is much higher than that of pure chitosan scaffolds,indicating that the layer-by-layer and wheel spokes complex structure is beneficial for the improvement of the mechanical properties of chitosan scaffolds.However,increasing the content of ferroferric oxide,the compressive strength of scaffolds decreased,because of the decreasing of chitosan crystallization and aggregation of magnetic particles as stress centralized body.Another reason is that the layer-by-layer and wheel spokes complex structure makes bigger contributions for the compressive strength than the layer-by-layer structure does.Three-dimensional ferroferric oxide/chitosan scaffolds could be used as hyperthermia generator system,improving the local circulation of blood,promoting the aggradation of calcium salt and stimulating bone tissue regeneration.

  2. Synthesis of Chitosan Quaternary Ammonium Salts

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A series of N-alkyl or N-aryl chitosan quaternary ammonium salts were prepared via Schiffs base intermediates. Quaternization of N-substituted chitosan derivatives was carried out using methyl iodide to produce water-soluble cationic chitosan quaternary ammonium salt. The products were characterized by IR, 1HNMR and elemental analysis. The degree of substitution of chitosan quaternary ammonium salt was calculated by elemental analysis.

  3. Application of irradiated chitosan for fruit preservation

    International Nuclear Information System (INIS)

    Preliminary test of mango (Mangifera indica) preservation by irradiated chitosan coating has been investigated. The coating by using irradiated chitosan in 1.5% solution has extended the shelf life of mango from 7 to 15 days. At the 15th day mango coated by irradiated chitosan has been keeping good color, natural ripening, without spoilage, weight loss 10%, whereas the mango without coating was spoiled completely and the coating of fruit with unirradiated chitosan inhibited the ripening. (author)

  4. Application of irradiated chitosan for fruit preservation

    Energy Technology Data Exchange (ETDEWEB)

    Lan, K.N. [Post-harvest Technology Institute, 4, Ngo Quyen-Ha Noi (Viet Nam); Lam, N.D. [Ha Noi Radiation Center, VAEC, 5T-160, Nghiado, Tuliem, Ha Noi (Viet Nam); Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2000-03-01

    Preliminary test of mango (Mangifera indica) preservation by irradiated chitosan coating has been investigated. The coating by using irradiated chitosan in 1.5% solution has extended the shelf life of mango from 7 to 15 days. At the 15th day mango coated by irradiated chitosan has been keeping good color, natural ripening, without spoilage, weight loss 10%, whereas the mango without coating was spoiled completely and the coating of fruit with unirradiated chitosan inhibited the ripening. (author)

  5. Characterization of Maize Producing Households in Southern Zambia

    Directory of Open Access Journals (Sweden)

    Thomson Kalinda

    2014-01-01

    Full Text Available Maize is an important crop in the livelihood of Zambia’s most vulnerable populations. A huge challenge facing most of Sub-Saharan Africa (SSA countries like Zambia is to increase maize productivity of smallholder farmers, which has remained very low over the past decades. Through various breeding programmes, more than 50 new maize hybrids and open-pollinated varieties have been developed and provided to the farmers through seed companies and Non-Governmental Organizations (NGOs. However, the extent to which such varieties have been adopted remains unknown. The purpose of this study was to characterize the maize producing households and to assess adoption of improved maize varieties. Data were collected from randomly selected households in the maize-producing areas of Monze and Kalomo Districts in southern Zambia. Principal Components Analysis (PCA on asset ownership was used to generate a wealth index used to rank the survey households. The results confirm that poorly endowed households, most of whom are female-headed, are far less likely to adopt improved varieties than their well-off counterparts. Important maize variety attributes sought by farmers include early maturity (85% of households, tolerance to water stress (83%, yield potential (79%, pest/disease resistance (56%, better processing quality (56% and cob/grain size (50%. A larger proportion of well endowed households planted improved varieties, compared with their poorly endowed counterparts. These findings suggest that moving the poor households and female-headed households up the wealth ladder poses a considerable challenge and calls for targeting the key factors that could potentially improve their welfare.

  6. Chitosan-supported Borohydride Reducing Agent

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new chitosan-supported borohydride reducing reagent (CBER) was prepared by treatment of KBH4 with the resin of chitosan derivative, which was first synthesized fiom the reaction of cross-linked chitosan microsphere with glycidyl trimethylammonium chloride. CBER could reduce aromatic carbonyl compound to corresponding alcohol.

  7. Antimicrobial properties of N-carboxybutyl chitosan.

    OpenAIRE

    Muzzarelli, R; Tarsi, R; Filippini, O; Giovanetti, E; G. Biagini; Varaldo, P E

    1990-01-01

    N-Carboxybutyl chitosan, a modified chitin of crustacean origin, displayed inhibitory, bactericidal, and candidacidal activities when tested against 298 cultures of various pathogens. Examination by electron microscopy showed that microbial cells exposed to N-carboxybutyl chitosan underwent marked morphological alterations. The data are of importance in defining the suitability of N-carboxybutyl chitosan as a wound dressing.

  8. THE DEVELOPMENT OF CHITOSAN NANOPARTICLES FROM HIBISCUS SABDARIFFA L CALYX EXTRACT FROM INDONESIA AND THAILAND

    Directory of Open Access Journals (Sweden)

    Nurkhasanah*, Tedjo Yuwono, Laela Hayu Nurani, Muhammad Ikhwan Rizki and Krisana Kraisintu

    2015-05-01

    Full Text Available Rosella (Hibiscus sabdariffa L calyx has been reported to have an antioxidant activity. Antocyanidin is the major compound of rosella and has low bioavailability as an ionic form. Rosella extract is an ucceptable due to high acidity. Development of chitosan nanoparticle from Hibiscus sabdariffa extract were expected to improve the bioavailability and the acidity problem. We studied the optimum pH and composition ratios of chitosan, extract and tripolyphosphate (TPP to develop chitosan-nanoparticle of rosella extract. We used rosella calyx both from Indonesia and Thailand to compare the physical characteristic the extract and nanoparticles. Rosella was extracted using 60% ethanol and water, followed by evaporation using evaporator and dried by freezedryer. The optimum formation of chitosan-nanoparticles of rosella extract were observed including pH formation and composition ratios between extract: chitosan: TPP. The physical charactersitics of nanoparticles were observed using transmission electron microscope (TEM and particle size analyzer (PSA. We found that optimum composition of extract: chitosan : TPP ratios were 2 : 1 : 0.1, with optimum formation of chitosan in acetate buffer pH 4. The characteristic of nanoparticles were spherical shapes with particles size range 60 to 300 nm, polydispersity index around 0.3 and zeta potential 39.19 to 62.26 mV. The nanoparticles has high entrapment efficiency of flavonoid active compound of 81.98 to 83.83%.

  9. Evaluation of Osseointegration Ability of Porous Polyethylene Implant (Medpor Treated with Chitosan

    Directory of Open Access Journals (Sweden)

    Kwang Kim

    2014-01-01

    Full Text Available Purpose. We suggest a successful and simple Medpor treated way with chitosan and evaluate more improved osseointegration ability of it than the orignal. Materials and Methods. Medpor was punched into circular shape and dipped into the chitosan gel solution. The Medpor plates soaked with chitosan were identified by the SEM images. We evaluated the growth rate of MC3T3-E1 cell using Von Kossa staining and MTT assay as in vitro experiment. And we implanted both Medpor plates into skull of domestic rabbits for in vivo experiment. We evaluated the osseointegration result with an optical microscope in postoperative 3 weeks and 6 weeks histologically. Results. The in vitro MC3T3-E1 cell growth rate on Medpor soaking with chitosan was faster than the original one in both Von Kossa staining and MTT assay. In animal test, Medpor soaking with chitosan shows more pronounced new bone than original Medpor too. Conclusion. Medpor soaking with chitosan was a successful modification. It is believed that the upgraded osseointegration ability of Medpor soaking with chitosan gives many benefits to clinicians using a Medpor implant for oral and maxillofacial reconstruction surgery.

  10. The molecular understanding of interfacial interactions of functionalized graphene and chitosan

    Science.gov (United States)

    Zhang, Hong-ping; Luo, Xue-gang; Lin, Xiao-yan; Lu, Xiong; Tang, Youhong

    2016-01-01

    Graphene-reinforced chitosan scaffolds have been extensively studied for several years as promising hard tissue replacements. However, the interfacial interactions between graphene and chitosan are strongly related to the solubility, processability, and mechanical properties of graphene-reinforced chitosan (G-C) composites. The functionalization of graphene is regarded as the most effective way to improve the abovementioned properties of the G-C composite. In this study, the interfacial interactions between chitosan and functionalized graphene sheets with carboxylization (COOH-), amination (NH2-), and hydroxylation (OH-) groups were systematically studied at the electronic level using the method of ab initio simulations based on quantum mechanics theory and the observations were compared with reported experimental results. The covalent linkages between COOH-modified graphene and the chitosan units were demonstrated and the combination of multi-functionalization on graphene could regulate the interfacial interactions between graphene and the chitosan. The interfacial interactions between chitosan and properly functionalized graphene are critical for the preparation of G-C-based composites for tissue engineering scaffolds and other applications.

  11. Effectiveness of Postharvest Treatment with Chitosan to Control Citrus Green Mold

    Directory of Open Access Journals (Sweden)

    Mohamed El Guilli

    2016-03-01

    Full Text Available Control of green mold, caused by Penicillium digitatum, by fungicides raises several problems, such as emergence of resistant pathogens, as well as concerns about the environment and consumers’ health. As potential alternatives, the effects of chitosan on green mold disease and the quality attributes of citrus fruits were investigated. Fruits were wounded then treated with different concentrations of chitosan 24 h before their inoculation with P. digitatum. The results of in vitro experiment demonstrated that the antifungal activity against P. digitatum was improved in concert to the increase of chitosan concentration. In an in vivo study, green mold was significantly reduced by chitosan treatments. In parallel, chitinase and glucanase activities were enhanced in coated fruits. Evidence suggested that effects of chitosan coating on green mold of mandarin fruits might be related to its fungitoxic properties against the pathogen and/or the elicitation of biochemical defense responses in coated fruits. Further, quality attributes including fruit firmness, surface color, juice content, and total soluble solids, were not affected by chitosan during storage. Moreover, the loss of weight was even less pronounced in chitosan-coated fruit.

  12. Effect of chitosan addition and gamma radiation on polymeric blends of PVP and PVAL

    International Nuclear Information System (INIS)

    The objective of this project is the study of the effect of chitosan addition and the radiation with gamma rays. The polymeric blend usage is a recent development that expanded the applications of the polymers, due to the improvement of the properties of a single polymer. The PVP and PVAL were chosen because they present the main required characteristics to the formation of a hydrogel, such as water absorption and crosslinking, and the chitosan to improve the interaction between the hydrogel and the organism. The flexibility of the PVP was added with the mechanical resistance of the PVAL and the chitosan biocompatibility. With a defined concentration of PVP and PVAL, films of this blend was irradiated and also solutions with different concentrations of chitosan was prepared to obtain new films of this blend. After obtaining the films, some assays were realized to evaluate the mechanical properties. (author)

  13. Molecular breeding for developing drought tolerant and disease resistant maize in sub Saharan Africa

    Science.gov (United States)

    The International Maize and Wheat Improvement Center (CIMMYT), in collaboration with public and private partners, is working on developing and disseminating drought tolerant maize for sub Saharan Africa (SSA) using pedigree selection and molecular breeding. In this paper, we provide an overview of ...

  14. Toward Cost-Effective Fingerprinting Methodology to Distinguish Maize Open-Pollinated Varieties

    Science.gov (United States)

    In Africa, many smallholder farmers grow open pollinated maize varieties (OPVs), as they allow seed recycling and out-yield traditional farmer’s (unimproved) landraces. One popular OPV, ZM521 released by the International Maize and Wheat Improvement Center (CIMMYT), has been provided to farmers, o...

  15. Immobilization of Lipase from Candida rugosa on Chitosan Beads for Transesterification Reaction

    OpenAIRE

    M. Nasratun; H. A. Said; Noraziah, A.; A. N.A. Alla

    2009-01-01

    Problem statement: Further study is recommended to improve the immobilization technique and the immobilized lipases performance as catalysis in transesterification reaction. Approach: To investigate the ability of immobilized lipase on chitosan beads to catalyze the transesterification of cooking oil to an ester. The porous bead of chitosan was used for immobilization of lipase from Candida rugosa by physical adsorption. Parameters like reaction time and oil to methanol molar ratios were stud...

  16. LYOTROPIC LIQUID CRYSTALLINE BEHAVIOR OF FIVE CHITOSAN DERIVATIVES

    Institute of Scientific and Technical Information of China (English)

    Yan-ming Dong; Zhi-qiang Li

    1999-01-01

    Five chitosan derivatives, i.e. O-butyryl chitosan, O-benzoyl chitosan, N-phthaloyl chitosan, N-maleoyl chitosan and O-cyanoethyl chitosan, were prepared from chitosan. All of them had better solubilitythan chitosan, and demonstrated lyotropic liquid crystalline behavior in various solvents. The critical liquid crystalline behavior of three O-substituted chitosan derivatives was evidently different from two Nsubstituted analogues. Typical fingerprint textures of cholesteric phase were only observed in three Osubstituted derivatives. The critical concentration (v/v%) of three O-substituted derivatives does not depend on the acidity of acidic solvents.

  17. Application of chitosan as flocculant for coprecipitation of Mn(II) and suspended solids from dual-alkali FGD regenerating process.

    Science.gov (United States)

    Wu, Zhong-Biao; Ni, Wei-Min; Guan, Bao-Hong

    2008-04-01

    Heavy metals and suspended solid (SS) needed to be removed from the recirculation of dual-alkali flue gas desulfurization (FGD) system. The feasibility of coprecipitation of heavy metal and SS by water-soluble chitosan was studied in a lab scale experiment. The association between chitosan and metal ions was verified through DSC and FT-IR. The pH investigation revealed that at the pH ranged from 5 to 9, there were three stages for different actions: adsorption of chitosan for Mn(II), precipitation of manganese hydroxide and coprecipitation of manganese hydroxide and chitosan-Mn(II) complex. The ion selectivity experiments showed that the occurrence of Ca(II) in the solution had little influence on the adsorption of chitosan for Mn(II). The decrease rate of adsorption capacity was about 0.0023 mmol g(-1) per 1 mg L(-1) Ca(II). When adsorption and flocculation of chitosan occurred at the same time and at the sufficient addition of chitosan, chitosan not only made solids flocculate but also enhanced sorption capacity of chitosan. Application of chitosan for coprecipitation of Mn(II) and SS could remove Mn(II) efficiently and improve the settling characteristics of SS from dual-alkali FGD regenerating process. PMID:17764834

  18. Maize and wheat yield improvement on small-scale farms in Uasin Gishu district: (I) The diagnosis of causes of low and declining yields (II) Proposed interventions to the identified constraint(s)

    International Nuclear Information System (INIS)

    Maize and wheat yields have been declining over the years in Uasin Gishu district. The average yields for maize and wheat from small-scale farms are 4200 and 1655 kg ha4, respectively (Hassan and Mwangi, 1991). The most popular and commonly used fertilizer for maize and wheat production in this area is di-ammonium phosphate (DAP). Acid soils caused by application of DAP has been suspected as one of the major constraints to production of these crops in the region. However, work in the same region on the influence of DAP on soil pH has indicated no effect (Ogola and Oduor, 1993). It is also suspected that poor soil fertility in general (soil fertility depletion) and degraded soils (low organic matter content soils) are constraints to maize and wheat production in the district. (author)

  19. Effect of PEGylation on the toxicity and permeability enhancement of chitosan.

    Science.gov (United States)

    Casettari, Luca; Vllasaliu, Driton; Mantovani, Giuseppe; Howdle, Steven M; Stolnik, Snow; Illum, Lisbeth

    2010-11-01

    The aim of the present work is to investigate if conditions can be devised where PEGylation of chitosan would reduce its toxicity toward the nasal mucosa while maintaining its ability to open the cellular tight junctions and, consequently, produce an enhancement of macromolecular permeability. A series of mPEG-g-chitosan copolymers with varying levels of mPEG substitution, mPEG molecular weight, and chitosan molecular weight were synthesized by grafting carboxylic acid-terminated mPEGs (Mw 1.9 and 5.0 × 10(3) g mol(-1)) to chitosans (Mw 28.9 and 82.0 × 10(3) g mol(-1)) using a NHS/EDC coupling system. The synthesized mPEG-g-chitosans were fully characterized using a number of techniques, including FT-IR, (1)H NMR, and SEC-MALLS and their physicochemical properties were analyzed by TGA and DSC. Thereafter, the conjugates were tested for their cytotoxicity and tight junction modulating property in a relevant cell model, a mucus producing Calu-3 monolayer. mPEG-g-chitosan conjugates exhibited reduced toxicity toward cells, as compared to unmodified chitosan counterparts. Furthermore, the conjugates demonstrated a dramatic effect on cell monolayer transepithelial electrical resistance (TEER) and enhancement of permeability of model macromolecules. TEER and permeability-enhancing effects, as measurable indicators of tight junction modulation, were found to be pH-dependent and were notably more pronounced than those exhibited by unmodified chitosans. This work therefore demonstrates that conditions can be contrived where PEGylation improves the toxicity profile of chitosan, while preserving its effect on epithelial tight junctions in the nose. PMID:20873757

  20. Effects of chitosan on nutrient digestibility, methane emissions, and in vitro fermentation in beef cattle.

    Science.gov (United States)

    Henry, D D; Ruiz-Moreno, M; Ciriaco, F M; Kohmann, M; Mercadante, V R G; Lamb, G C; DiLorenzo, N

    2015-07-01

    Chitosan was evaluated as a feed additive to mitigate in vivo CH4 emissions in beef cattle. Twenty-four crossbred heifers (BW = 318 ± 35 kg) were used in a randomized block design replicated in 2 periods. The design included a 2 × 3 factorial arrangement of treatments, which included diet (high concentrate [HC] or low concentrate [LC]) and 0.0, 0.5, or 1.0% of chitosan inclusion (DM basis). Diets were offered ad libitum and individual intake was recorded. An in vitro experiment to analyze chitosan’s effect on fermentation parameters and gas production kinetics was performed. A diet effect (P 0.10) by chitosan in HC substrate; however, when incubated with the LC substrate, CH4 production increased quadratically (P < 0.01) as chitosan inclusion increased. A digestibility marker × diet interaction occurred (P < 0.05) for DM, OM, CP, NDF, and ADF digestibility. Diet × chitosan interactions (P < 0.05) occurred for DM, OM, NDF, and ADF digestibility when Cr2O3 was used. When TiO2 was used, diet × chitosan interactions (P < 0.05) were observed for NDF and ADF. However, using indigestible NDF as an internal marker, DM and OM digestibility were improved (P < 0.05) by 21 and 19%, respectively, when chitosan was included in LC diets. In conclusion, feeding up to 1% of chitosan (DM basis) to heifers consuming a LC diet increased apparent total tract digestibility of nutrients. Enteric CH4 emissions were not affected by chitosan feeding, regardless of type of diet, and heifers consuming a 36% concentrate diet produced 2.6 times more methane per day than those consuming an 85% concentrate diet. PMID:26440023

  1. Physical characteristics of chitosan-silica composite of rice husk ash

    Science.gov (United States)

    Sumarni, Woro; Sri Iswari, Retno; Marwoto, Putut; Rahayu, Endah F.

    2016-02-01

    Some previous studies showed that the characteristics of chitosan membranes have a very rigid and non-porous structure so that its utilization is not maximized, particularly in the filtration process. Hence, it needs modification to improve the quality of the chitosan membranes. Adding the silica into the chitosan membranes is one of the offered solutions to overcome the problems of physical and mechanical properties of chitosan. This study aims to investigate the effect of variations in the silica composition to the physical characteristics of the chitosan-silica membranes of rice husk ash that were synthesized. The chitosan used is derived from the chitin of Vannamei shrimps’ shell with 82% degree of de-acetylation, while the silica was synthesized from rice husk ash with rendering of silica (SiO2) by 5% and the results of XRD analysis showed an amorphous phase. Membrane synthesis was performed using the phase inversion method with chitosan-silica mass ratios of rice husk ash, which were 1:0.0; 1:0.5; 1:1.0; 1:1.5 and 1:2.0. The results showed that the addition of silica increases the swelling index and the membrane permeability. The results of the analysis, FTIR spectra, obtained a new functional group after the addition of silica, they are Si-OH, Si-O-Si, and CO- NH2. The morphology test using CCD Microscope MS-804 results in the very tight chitosan membranes without the silica surface, it has no pores, smooth and homogeneous, while the chitosan-silica composite membrane of rice husk ash obviously has cracks and small cavities that seemed to spread out.

  2. Influence of Water Stress on Endogenous Hormone Contents and Cell Damage of Maize Seedlings

    Institute of Scientific and Technical Information of China (English)

    Chunrong Wang; Aifang Yang; Haiying Yin; Juren Zhang

    2008-01-01

    Phytohormones play critical roles In regulating plant responses to stress. We Investigated the effects of water stress Induced by adding 12% (w/v) polyethylene glycol to the root medium on the levels of abscisic acid (ABA), indole-3-acid (IAA), zeatin (ZT), and gibberellin3 (GA3) in maize leaves. The results suggested that water stress had significant effects on the four hormone levels. There was a transient increase in the IAA content during the initial stage of adaptation to water stress in maize leaves, but it dropped sharply thereafter in response to water stress. ABA content increased dramatically in maize leaves after 24 h of exposure to water stress, and then the high levels of ABA were maintained to the end, The contents Of ZT and GA3 rapidly declined in maize leaves subjected to water stress. The effects of water stress on chlorophyll content, electrolyte leakage and malondialdehyde levels in maize leaves were also studied. The variation of cell damage was negatively correlated with ZT and GA3 levels in maize leaves under water stress. Thus, we explored the roles of ZT and GA3 on the growth of maize seedlings under water stress by exogenous application. It is possible that both ZT and GA3 were effective in protecting maize seedlings from water stress, which would be of great importance for the improvement of drought tolerance in maize by genetic manipulation.

  3. Methylated 4-N,N dimethyl aminobenzyl N,O carboxymethyl chitosan as a new chitosan derivative: Synthesis, characterization, cytotoxicity and antibacterial activity.

    Science.gov (United States)

    Rahmani, Soheila; Mohammadi, Zohreh; Amini, Mohsen; Isaei, Elham; Taheritarigh, Sadegh; Rafiee Tehrani, Niyousha; Rafiee Tehrani, Morteza

    2016-09-20

    Chitosan, as a biocompatible polymer, is very attractive for biomedical applications. Continues studies are performing for improving its physicochemical features in order to make it more suitable for such approaches. In this study, methylated 4-N,N dimethyl aminobenzyl N,O carboxymethyl chitosan (MABCC) was synthesized,as a new chitosan derivative, in three steps. The investigations were carried out using FTIR, NMR, TGA and zeta potential measurement. Antibacterial and cell viability assessments were performed on four bacterial strains and two cell lines respectively. FTIR and NMR results showed that all substitution reactions were successfully carried out. Zeta potential of MABCC at various pH especially alkaline pH was greater than chitosan and it revealed increasing the solubility of the derivative. Antibacterial activity of MABCC was extremely greater than chitosan especially in Gram positive bacteria.Furthermore,it had no significant cytotoxicity against MCF-7 and Skov-3 cell lines in comparison to chitosan. These findings confirm that this new derivative can be introduced as a suitable compound for biomedical purposes. PMID:27261738

  4. Synthesis of PVA-Chitosan Hydrogels for Wound Dressing Using Gamma Irradiation. Part I: Radiation Degradation of Chitosan in Solid State and in Solution

    International Nuclear Information System (INIS)

    Chitosan is a partially deacetylated product of chitin, a very abundant polysaccharide, existing in exoskeleton of crustaceans. It is a polymer consisting of glucosamine and N-acetylglucosamine units linked by β-1-4-glycosidic bonds. Chitosan, like others polysaccharides, such as cellulose derivatives, alginates and carrageenan is widely used in food, medicine and cosmetic fields. Chitosan presents a variety of distinctive properties, such as biocompatibility, biodegradability, nontoxicity and nonantigenicity. Chitosan obtained by the deacetylation of chitin has, generally, a high molecular weight, which limits its solubility in aqueous solvents. The reduction of its molecular weight by degradation is usually used in order to improve its water solubility. Water-soluble chitosan exhibit some specific properties, such as antifungal activity, antimicrobial activity and plant growth promotion. Among the methods that have been tried to produce low molecular weight chitosan, radiation processing is the most promising one, since the process is simple, it is carried out at room temperature and no purification of the product is required after processing

  5. SYNTHESIS AND PROPERTIES OF SULFHYDRYL CHITOSAN

    Institute of Scientific and Technical Information of China (English)

    杨宇民; 邵健; 姚成

    2001-01-01

    A new adsorbent for heavy metal ions, sulfhydryl chitosan (S-chitosan), was produced by treatment of chitosan with sulhydryl acetic acid in the presence of sulfuric acid as a catalyst. Its structure was confirmed by elemental analysis and FT-IR spectra analysis. The adsorption properties of sulfhydryl chitosan for Cu( Ⅱ ), Cd( Ⅱ ), Pb( Ⅱ ), Cr( Ⅲ ) and Ni( Ⅱ ) were investigated, and the effect of pH value on adsorption, adsorption kinetics, and selective adsorption was examined. It was shown that S-chitosan has good adsorption for Pb( Ⅱ ), Cu( Ⅱ ) and Cd( Ⅱ ) like chitosan, is also insoluble in acid solution; has good adsorption kinetic properties for heavy metal ions; and can be used in acid solution. The adsorption capacities of S-chitosan can be affected by media acidity. The adsorbed Cu( Ⅱ ) Cd ( Ⅱ )and Pb( Ⅱ ) could be eluted by diluted chlorhydric acid.

  6. SYNTHESIS AND PROPERTIES OF SULFHYDRYL CHITOSAN

    Institute of Scientific and Technical Information of China (English)

    杨宇民; 邵健; 姚成

    2001-01-01

    A new adsorbent for heavy metal ions, sulfhydryl chitosan (S-chitosan), was produced by treatment of chitosan with sulhydryl acetic acid in the presence of sulfuric acid as a catalyst. Its structure was confrrmed by elemental analysis and FI'-IR spectra analysis. The adsorption properties of sulthydryl chitosan for Cu(Ⅱ ), Cd(Ⅱ ), Pb(Ⅱ), Cr(Ⅲ) and Ni(Ⅱ) were investigated, and the effect of pH value on adsorption, adsorption kinetics, and selective adsorption was examined. It was shown that S-chitosan has good adsorption for Pb(Ⅱ), Cu(Ⅱ) and Cd(Ⅱ) like chitosan, is also insoluble in acid solution; has good adsorption kinetic properties for heavy metal ions; and can be used in acid solution. The adsorption capacities of S-chitosan can be affected by media acidity. The adsorbed Cu(Ⅱ) Cd(Ⅱ) and Pb(Ⅱ) could be eluted by diluted chlorhydric acid.

  7. Anti-fungal activity of irradiated chitosan

    International Nuclear Information System (INIS)

    Anti-fungal activity of chitosan induced by irradiation has been investigated. Commercial chitosan samples of 8B (80% deacetylation) and l0B (99% deacetylation) were irradiated by γ-ray in dry condition. Highly deacethylated chitosan (10B) at low dose irradiation (75 kGy) was effective for inhibition of fungal growth. The sensitivities of Exobasidium vexans, Septoria chrysanthemum and Gibberella fujikuroi for the irradiated chitosan were different and the necessary concentrations of chitosan were 550, 350 and 250 μg/ml, respectively. For the plant growth, low deacethylation (chitosan 8B) and high dose (500 kGy) was effective and the growth of chrysanthemum was promoted by spraying the irradiated chitosan. (author)

  8. LOW MOLECULAR WEIGHT O-CARBOXYMETHYLATED CHITOSANS DERIVED FROM IRRADIATED CHITOSAN AND THEIR ANTIBACTERIAL ACTIVITY

    Institute of Scientific and Technical Information of China (English)

    Xu-pin Zhuang; Xiao-fei Liu; Zhi Li; Yun-lin Guan; Kang-de Yao

    2004-01-01

    Original chitosan with My of 2.7 × 10 5 was degraded by irradiation with y-rays and a series of low molecular weight O-carboxymethylated chitosans (O-CMCh) were prepared based on the irradiated chitosan. A kinetic model of the irradiation of chitosan was put forward. Results show that the irradiation degradation of chitosan obeys the rule of random degradation and the degree of deacetylation of irradiated chitosan is slightly raised. The antibacterial activity of O-CMCh is significantly influenced by its MW, and a suppositional antibacterial peak appears when Mv is equal to 2 × 10 5.

  9. Applying CSM-CERES-Maize to define a sowing window for irrigated maize crop - The Riacho´s Farm case study

    Directory of Open Access Journals (Sweden)

    Denise Freitas Silva

    2011-08-01

    Full Text Available Irrigation use constitutes an alternative to improve maize production in Central Minas Gerais State, Brazil. However, even under adequate water supply conditions, other environmental factors may influence maize crop growth and development and may, ultimately, affect grain yield. This study aimed to establish a sowing window for irrigated maize crop, based on simulation results obtained with the decision support model CSM-CERES-Maize. Simulations were made for crop management conditions of Riacho´s Farm, located in Matozinhos, Minas Gerais State, Brazil. It was employed the model´s seasonal tool, along with a data set containing 46 years of weather data records, to simulate maize yield for weekly sowing scenarios, starting on August 1st and ending on July 24th of each year. One defined an irrigated maize sowing window, taking into account the yield break risk that a farmer would be willing to take. The model proved to be an interesting tool to assist in decision making, regarding crop and irrigation management, for an irrigated maize production system. Assuming a 10% yield break in the expected average maximum maize yield, it was defined as sowing window, the period from January 23rd to March 6th, with February 20th as the best sowing date. Other sowing windows may be established according to the risk that the farmer would be willing to take.

  10. Gadolinium-loaded chitosan nanoparticles for cancer neutron-capture therapy. Pharmaceutical characteristics and in vitro antitumor effect

    International Nuclear Information System (INIS)

    Preparation of Gd-nanoCPs was carried out based on the w/o emulsion-droplet coalescence technique. Chitosan with different molecular weight (Mw) (950, 50, 10 kDa) was applied a various concentrations (0.5, 1.5, 2.5%). B16F10 mouse melanoma cells were employed to evaluate the cell-association properties of Gd-nanoCPs and the antitumor effect with thermal neutron irradiation. In the formulation study, as the Mw of chitosan decreased, the mean particle diameter decreased to 155 nm with 10 kDa chitosan at the smallest. Then, decrease in the chitosan concentration in the chitosan solution contributed to a decrease in mean particle diameter and an increase in gadolinium content. The Gd content in the Gd-nanoCPs prepared with 0.5% chitosan reached 22% at the maximum. The amount of Gd associated with cell was also dependent on the Mw of chitosan. In the subsequent Gd-NCT study in vitro, the most highly Gd-containing (22%) and finest (155 nm) Gd-nanoCPs prepared at 0.5% of 10 kDa chitosan exhibited the strongest tumor cell growth suppression. It is expected that use of Gd-nanoCP prepared here may lead to improved performance in NCT. (author)

  11. Design of chitosan-based nanoparticles functionalized with gallic acid.

    Science.gov (United States)

    Lamarra, J; Rivero, S; Pinotti, A

    2016-10-01

    Active nanoparticles based on chitosan could be applied as a support for the modulation of gallic acid delivery. In this sense, these nanostructures could be employed in different fields such as food, packaging, and pharmaceutical areas. The design parameters of chitosan-based nanoparticles functionalized with gallic acid (GA) were optimized through RSM by means of the analysis of zeta potential (ZP) and percentage encapsulation efficiency (PEE). The nanoparticles were prepared by ionotropic gelation using tripolyphosphate (TPP), at different combinations of chitosan (CH) concentration, CH:TPP ratio and GA. Global desirability methodology allowed finding the optimum formulation that included CH 0.76% (w/w), CH:TPP ratio of 5 and 37mgGA/gCH leading to ZP of +50mV and 82% of PEE. Analysis through QuickScan and turbidity demonstrated that the most stable nanoparticle suspensions were achieved combining concentrations of chitosan ranging between 0.5 and 0.75% with CH:TPP ratios higher than 3. These suspensions had high stability confirmed by means ZP and transmittance values which were higher than +25mV and 0.21 on average, respectively, as well as nanoparticle diameters of about 140nm. FTIR revealed the occurrence of both hydrogen bond and ionic interactions of CH-TPP which allowed the encapsulation and the improvement of the stability of the active agent. PMID:27287172

  12. Versatile carboxymethyl chitin and chitosan nanomaterials: a review.

    Science.gov (United States)

    Narayanan, Deepa; Jayakumar, R; Chennazhi, K P

    2014-01-01

    Biocompatibility, biodegradability, and low cost of chitin and chitosan have drawn immense attention in many fields including medicine, bioinspired material science, pharmaceuticals, and agriculture. Their handling and processing are difficult owing to its insolubility in neutral aqueous solution or organic solvents. One of the methods used to improve the solubility characteristics of chitin and chitosan is chemical modification. Introducing a carboxymethyl group is the most advantageous method of increasing the solubility of chitosan at neutral and alkaline pH. Carboxymethyl chitin (CMC) and carboxymethyl chitosan (CMCS) are water soluble derivatives formed by introducing CH₂COOH function into the polymer which endows it with better biological properties. The functional group makes CMC/CMCS nanoparticles (NPs) efficient vehicles for the delivery of DNA, proteins, and drugs. This review provides an overview of the characteristics of CMC/CMCS NPs as well as fulfills the task of describing and discussing its important roles primarily in cancer nanomedicine detailing the targeted drug delivery aspect. The application of these NPs in imaging, agriculture, and textiles has also been highlighted. The review also elaborates the advantages of using the CMC and CMCS NPs for drug and gene delivery. PMID:25266740

  13. Enriched fluoride sorption using alumina/chitosan composite

    International Nuclear Information System (INIS)

    Alumina possesses an appreciable defluoridation capacity (DC) of 1566 mg F-/kg. In order to improve its DC, it is aimed to prepare alumina polymeric composites using the chitosan. Alumina/chitosan (AlCs) composite was prepared by incorporating alumina particles in the chitosan polymeric matrix, which can be made into any desired form viz., beads, candles and membranes. AlCs composite displayed a maximum DC of 3809 mg F-/kg than the alumina and chitosan (52 mg F-/kg). The fluoride removal studies were carried out in batch mode to optimize the equilibrium parameters viz., contact time, pH, co-anions and temperature. The equilibrium data was fitted with Freundlich and Langmuir isotherms to find the best fit for the sorption process. The calculated values of thermodynamic parameters indicate the nature of sorption. The surface characterisation of the sorbent was performed by FTIR, AFM and SEM with EDAX analysis. A possible mechanism of fluoride sorption by AlCs composite has been proposed. Suitability of AlCs composite at field conditions was tested with a field sample taken from a nearby fluoride-endemic village. This work provides a potential platform for the development of defluoridation technology.

  14. Advances in the targeting molecules modified chitosan-based nanoformulations.

    Science.gov (United States)

    Du, Hongliang; Cai, Xiaoqing; Zhai, Guangxi

    2013-08-01

    Chitosan, a cationic polysaccharide, has prompted the continuous impetus for the development of safe and effective drug delivery systems due to its unique properties such as mucoadhesive feature, absorption enhancement and active functional groups for chemical modifications. By using chitosan-based nanoformulations, many studies have attempted to improve the dispersion of loaded hydrophobic drugs in aqueous environment, protect the encapsulated proteins and genes against enzymatic degradation, and increase their absorption by target tissues. It's noteworthy that the derivatization of chitosan-based carriers with a ligand leads to the selective targeting of the nanoformulations to selected cells, thereby facilitating far more sensitive internalization and localization of nanoformulations for diseases' diagnosis and treatment. As such, this review focuses on some of the most poignant reports of the utility of targeting molecules such as carbohydrates, antibodies, peptides and some small molecules in chitosan-based nanoformulations for targeted delivery. Additionally, the affinity mechanism of different targeting molecules and the pros and cons of their conjugation strategies will be illustrated summarily. PMID:23469876

  15. Novel Chitosan-based Biomaterials

    Institute of Scientific and Technical Information of China (English)

    Mingchun Li; Meihua Xin

    2005-01-01

    @@ 1Introduction Chitosan with two long side chains of N-alkyl group is an important amphiphilic material, which has potential application in tissue engineering and drug delivery system. In this paper the amphiphilic N, N-dilauryl chitosan has been prepared by the phase transfer catalysis. The π-A isotherms of the products were measured in order to find some fundamental data for making self-assembled vesicles out of this kind of material. The LB film experiment indicates that N, N-dilauryl chitosan can form ultrathin LB film with highly ordered layer structure and smooth surface. The thickness of each layer of the LB film was measured as 1.74 nm by XRD.

  16. Electrorheological Performance of SiO2 Particle Materials of Ce-Doping and Adsorbed Chitosan

    Institute of Scientific and Technical Information of China (English)

    Li Shuxin; Ma Shuzhen; Xu Mingyuan; Shang Yanli; Li Junran; Zhang Shaohua; Zhang Yuanjing; Gao Song

    2004-01-01

    The electrorheological(ER) materials of pure SiO2 ( Sample 1 ), Ce-doping SiO2 ( Ce-SiO2, Sample 2) and Ce-SiO2 adsorbed chitosan (Ce-SiO2-chitosan, Sample 3 ) were prepared using Na2SiO3, Ce( NO3 )3 and chitosan as starting materials. Their ER properties were studied. The results show that Ce-doping can enhance the ER activity of SiO2, and the ER activity of SiO2 can be further improved by adsorbing chitosan on the surfaces of Ce-SiO2 particles.The ER activity of a particle material is correlated with the average grain size, surface area, pore volume and average pore size of the material.

  17. Effects of laminin blended with chitosan on axon guidance on patterned substrates

    International Nuclear Information System (INIS)

    Axon guidance is a crucial consideration in the design of tissue scaffolds used to promote nerve regeneration. Here we investigate the combined use of laminin (a putative axon adhesion and guidance molecule) and chitosan (a leading candidate base material for the construction of scaffolds) for promoting axon guidance in cultured adult dorsal root ganglion (DRG) neurons. Using a dispensing-based rapid prototyping (DBRP) technique, two-dimensional grid patterns were created by dispensing chitosan or laminin-blended chitosan substrate strands oriented in orthogonal directions. In vitro experiments illustrated DRG neurites on these patterns preferentially grew upon and followed the laminin-blended chitosan pathways. These results suggest that an orientation of neurite growth can be achieved in an artificially patterned substrate by creating selectively biofunctional pathways. The DBRP technique may provide improved strategies for the use of biofunctional pathways in the design of three-dimensional scaffolds for guidance of nerve repair.

  18. Green synthesis of magnetic chitosan nanocomposites by a new sol-gel auto-combustion method

    Science.gov (United States)

    Ansari, Fatemeh; Sobhani, Azam; Salavati-Niasari, Masoud

    2016-07-01

    The Fe2O3/CuFe2O4/chitosan nanocomposites have been successfully synthesized via a new sol-gel auto-combustion route. To prepare the nanocomposites, copper ferrite (CuFe2O4) and iron (II) oxide (Fe2O3) nanostructures were first prepared utilizing onion as a green reductant for the first time, and characterized by SEM, TEM, XRD, IR and VSM. Then chitosan was added into the nanostructures dispersed in water. Chitosan was used to functionalize and modify the nanostructures and also to improve surface properties. The nanocomposites were also characterized by several techniques including SEM, TEM, XRD, IR and VSM. The effects of amount of onion and chitosan on the morphology and particle size of nanocomposites were evaluated.

  19. Investigation the Porous Collagen-Chitosan /Glycosaminoglycans for Corneal Cell Culture as Tissue Engineering Scaffold

    Institute of Scientific and Technical Information of China (English)

    LI Qin-Hua; CHEN Jian-Su

    2005-01-01

    The objective of this study was to produce the porous collagen-chitosan/Glycosanminglycans (GAG) for corneal ceil-seed implant as a three-dimensional tissue engineering scaffold to improve the regeneration corneas. The effect of various content of glycerol as form porous agent to collagen-chitosan/GAG preserved a porous dimensional structure was investigated. The heat-drying was used to prepare porous collagen-chitosan /GAG scaffold. The pore morphology of collagenchitosan/GAG was controlled by changing the concentration of glycerol solution and drying methods. The porous structure morphology was observed by SEM. The diameter of the pores form 10 to 50 μm. The highly porous scaffold had interconnecting pores. The corneal cell morphology was observed under the light microscope. These results suggest that collagen-chitosan/GAG showed that corneal cell have formed confluent layers and resemble the surface of normal corneal cell surface.

  20. Effects of laminin blended with chitosan on axon guidance on patterned substrates

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, N; Guan, Y J; Chen, X B [Division of Biomedical Engineering, University of Saskatchewan, Saskatoon S7N 5A9 (Canada); Li, M G [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon S7N 5A9 (Canada); Schreyer, D J, E-mail: niz504@mail.usask.c [Department of Anatomy and Cell Biology, Cameco MS Neuroscience Research Center, University of Saskatchewan, Saskatoon, S7K 0M7 (Canada)

    2010-12-15

    Axon guidance is a crucial consideration in the design of tissue scaffolds used to promote nerve regeneration. Here we investigate the combined use of laminin (a putative axon adhesion and guidance molecule) and chitosan (a leading candidate base material for the construction of scaffolds) for promoting axon guidance in cultured adult dorsal root ganglion (DRG) neurons. Using a dispensing-based rapid prototyping (DBRP) technique, two-dimensional grid patterns were created by dispensing chitosan or laminin-blended chitosan substrate strands oriented in orthogonal directions. In vitro experiments illustrated DRG neurites on these patterns preferentially grew upon and followed the laminin-blended chitosan pathways. These results suggest that an orientation of neurite growth can be achieved in an artificially patterned substrate by creating selectively biofunctional pathways. The DBRP technique may provide improved strategies for the use of biofunctional pathways in the design of three-dimensional scaffolds for guidance of nerve repair.

  1. A study on biosorption of copper ions by fungal chitosan: an alternative to shrimp chitosan

    Directory of Open Access Journals (Sweden)

    Sanaz Behnam

    2015-02-01

    Full Text Available   Introduction : One of the main applications of chitosan is for heavy metals removal from waste waters. Industrially, chitosan is produced through deacetylation of chitin present in shellfish waste. Another source of chitosan is the cell wall of zygomycetes fungi with several advantages over shellfish wastes .   Materials and method s: Fungal chitosan purified from biomass of Mucor indicus and shrimp chitosan were applied and compared for removal of copper ions from aqueous solution. The effects of pH (3 to 5.5, copper ion concentration (5 to 52 mg l-1, the amount of chitosan (200 to 3000 mg l-1, adsorption time, temperature, and presence of other metal ions on the biosorption of Cu2+ were investigated .   Results : Maximum adsorption capacities for fungal and shrimp chitosans were 58.5 and 60.7 mg g-1, respectively. T he rate of copper adsorption by the fungal chitosan was significantly higher than that by the shrimp chitosan. Among p seudo-first order, pseudo-second order, intra-particle diffusion, and Elovich models, Ho’s pseudo-second order model was the best model for fitting the kinetic data. The adsorption capacity increased for both types of chitosans by increasing the solution pH. However, temperature and presence of other ions did not show significant effects on the biosorption capacity of copper. The isotherm data were very well described by Langmuir, Freundlich, and Redlich-Peterson models .   Discussion and conclusion : Both fungal and shrimp chitosans can effectively be used for removal of copper ions from aqueous solutions. Adsorption process for fungal chitosan is fast, while the process is slower for the shrimp chitosan. Therefore, from the kinetics point of view, the fungal chitosan is preferable compared with the shrimp chitosan . Key words: Biosorption, Copper, Fungal chitosan, Shrimp chitosan, Water treatment .

  2. A study on the performance of hyaluronic acid immobilized chitosan film

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yingjun; Guo Li; Ren Li; Yin Shiheng [Biomaterial Research Institute, College of Material Science and Engineering, South China University of Technology, Guangzhou, 510640 (China); Ge Jian; Gao Qianying [State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060 (China); Luxbacher, Thomas; Luo Shijing, E-mail: imwangyj@scut.edu.c, E-mail: psliren@scut.edu.c [Anton Paar GmbH, Anton-Paar-Strasse 20, A-8054 Graz (Austria)

    2009-06-15

    In order to improve hydrophilicity and biocompatibility of chitosan, hyaluronic acid was immobilized onto the surface of chitosan film. The structure of films was characterized by Fourier transformed infrared spectroscopy with attenuated total reflectance (ATR-FTIR), x-ray photoelectron spectroscopy (XPS) and zeta potential. Results confirmed that hyaluronic acid was successfully immobilized on chitosan film. Transparency, water absorption percentage and contact angle of films were characterized. Results showed that there was no significant variation in transparency (p < 0.05) before and after immobilization, the maximum was up to 99% which was enough for corneal regeneration in clinical applications. After the immobilization, the time-dependent contact angle declined sharply (from 91.8 deg. to 67.7 deg. at 100 s). The hydrophilicity was significantly improved. The methylthiazol tetrazolium (MTT) (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay was used to assess cell viability and proliferation. Results showed that human cornea epithelial cells (HCEC) grew better on hyaluronic acid immobilized chitosan films than on chitosan films. The hyaluronic acid immobilized chitosan film could be a promising candidate material for corneal regeneration.

  3. A study on the performance of hyaluronic acid immobilized chitosan film

    International Nuclear Information System (INIS)

    In order to improve hydrophilicity and biocompatibility of chitosan, hyaluronic acid was immobilized onto the surface of chitosan film. The structure of films was characterized by Fourier transformed infrared spectroscopy with attenuated total reflectance (ATR-FTIR), x-ray photoelectron spectroscopy (XPS) and zeta potential. Results confirmed that hyaluronic acid was successfully immobilized on chitosan film. Transparency, water absorption percentage and contact angle of films were characterized. Results showed that there was no significant variation in transparency (p < 0.05) before and after immobilization, the maximum was up to 99% which was enough for corneal regeneration in clinical applications. After the immobilization, the time-dependent contact angle declined sharply (from 91.8 deg. to 67.7 deg. at 100 s). The hydrophilicity was significantly improved. The methylthiazol tetrazolium (MTT) (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay was used to assess cell viability and proliferation. Results showed that human cornea epithelial cells (HCEC) grew better on hyaluronic acid immobilized chitosan films than on chitosan films. The hyaluronic acid immobilized chitosan film could be a promising candidate material for corneal regeneration.

  4. Microbial enhance of chitosan production by Rhizopus arrhizus using agroindustrial substrates.

    Science.gov (United States)

    Cardoso, Antonio; Lins, Clarissa Izabel M; dos Santos, Ednaldo Ramos; Freitas Silva, Marta C; Campos-Takaki, Galba M

    2012-01-01

    This study investigated the potential of Rhizopus arrhizus UCP 402 for producing chitosan using corn steep liquor and honey as agroindustrial nitrogen and carbon sources. A complete factorial design was used to assess the improved biomass and chitosan production. The results were evaluated using Pareto charts (Statistica 7.0 software). The chitosan obtained was characterized by X-ray diffraction. The cristallinity index (I(C)), and infrared spectroscopy (FTIR) were used to evaluate the degree of deacetylation (DD %). The morphological aspects of the R. arrhizus were evaluated by measuring the diameter of the colonies by light microscopy. The results obtained showed higher biomass and chitosan yields (20.61 g/L and 29.3 mg/g), respectively, in the selected assays. The characterization of the macromolecular arrangement of chitosan showed a crystallinity index compatible with the literature, and the infrared peaks confirmed a degree of 86%. The experimental data obtained suggest that adding honey to corn steep liquor is a promising way to improve microbiological chitosan production. PMID:22543505

  5. Microbial Enhance of Chitosan Production by Rhizopus arrhizus Using Agroindustrial Substrates

    Directory of Open Access Journals (Sweden)

    Marta C. Freitas Silva

    2012-04-01

    Full Text Available This study investigated the potential of Rhizopus arrhizus UCP 402 for producing chitosan using corn steep liquor and honey as agroindustrial nitrogen and carbon sources. A complete factorial design was used to assess the improved biomass and chitosan production. The results were evaluated using Pareto charts (Statistica 7.0 software. The chitosan obtained was characterized by X-ray diffraction. The cristallinity index (IC, and infrared spectroscopy (FTIR were used to evaluate the degree of deacetylation (DD %. The morphological aspects of the R. arrhizus were evaluated by measuring the diameter of the colonies by light microscopy. The results obtained showed higher biomass and chitosan yields (20.61 g/L and 29.3 mg/g, respectively, in the selected assays. The characterization of the macromolecular arrangement of chitosan showed a crystallinity index compatible with the literature, and the infrared peaks confirmed a degree of 86%. The experimental data obtained suggest that adding honey to corn steep liquor is a promising way to improve microbiological chitosan production.

  6. Microbial Enhance of Chitosan Production by Rhizopus arrhizus Using Agroindustrial Substrates

    Directory of Open Access Journals (Sweden)

    Marta C. Freitas Silva

    2012-04-01

    Full Text Available This study investigated the potential of Rhizopus arrhizus UCP 402 for producing chitosan using corn steep liquor and honey as agroindustrial nitrogen and carbon sources. A complete factorial design was used to assess the improved biomass and chitosan production. The results were evaluated using Pareto charts (Statistica 7.0 software. The chitosan obtained was characterized by X-ray diffraction. The cristallinity index (IC, and infrared spectroscopy (FTIR were used to evaluate the degree of deacetylation (DD %. The morphological aspects of the R. arrhizus were evaluated by measuring the diameter of the colonies by light microscopy. The results obtained showed higher biomass and chitosan yields (20.61 g/L and 29.3 mg/g, respectively, in the selected assays. The characterization of the macromolecular arrangement of chitosan showed a crystallinity index compatible with the literature, and the infrared peaks confirmed a degree of 86%. The experimental data obtained suggest that adding honey to corn steep liquor is a promising way to improve microbiological chitosan production.

  7. Effect of chitosan and thiolated chitosan coating on the inhibition behaviour of PIBCA nanoparticles against intestinal metallopeptidases

    International Nuclear Information System (INIS)

    Surface modified nanoparticles composed of poly(isobutylcyanoacrylate) (PIBCA) cores surrounded by a chitosan and thiolated chitosan gel layer were prepared and characterized in previous works. The presence of such biopolymers on the nanoparticle surface conferred those nanosystems interesting characteristics that might partially overcome the gastrointestinal enzymatic barrier, improving the oral administration of pharmacologically active peptides. In the present work, the antiprotease behaviour of this family of core-shell nanoparticles was in vitro tested against two model metallopeptidases present in the gastrointestinal tract (GIT): Carboxypeptidase A -CP A- (luminal protease) and Leucine Aminopeptidase M -LAP M- (membrane protease). As previous step, the zinc-binding capacity of these nanoparticles was evaluated. Interestingly, an improvement of both the zinc-binding capacity and the antiprotease effect of chitosan was observed when the biopolymers (chitosan and thiolated chitosan) were used as coating component of the core-shell nanoparticles, in comparison with their behaviour in solution, thanks to the different biopolymer chains rearrangement. The presence of amino, hydroxyl and thiol groups on the nanoparticle surface promoted zinc binding and hence the inhibition of the metallopeptidases analysed. On the contrary, the occurrence of a cross-linked structure in the gel layer surrounding the PIBCA cores of thiolated formulations, due to the formation of interchain and intrachain disulphide bonds, partially limited the inhibition of the proteases. The low accessibility of cations to the active groups of the cross-linked polymeric shell was postulated as a possible explanation of this behaviour. Results obtained in this work make this family of surface-modified nanocarriers promising candidates for the successfull administration of pharmacologically active peptides and proteins by the oral route.

  8. Determination of physical properties for β-TCP + chitosan biomaterial obtained on metallic 316L substrates

    Energy Technology Data Exchange (ETDEWEB)

    Mina, A. [Tribology, Powder Metallurgy and Processing of Solid Recycled Research Group, Universidad del Valle, Cali (Colombia); Tecno-Academia ASTIN SENA Reginal Valle (Colombia); Castaño, A. [Tribology, Powder Metallurgy and Processing of Solid Recycled Research Group, Universidad del Valle, Cali (Colombia); Caicedo, J.C., E-mail: julio.cesar.caicedo@correo.univalle.edu.co [Tribology, Powder Metallurgy and Processing of Solid Recycled Research Group, Universidad del Valle, Cali (Colombia); Caicedo, H.H. [Biologics Research, Biotechnology Center of Excellence, Janssen R& D, LLC, Pharmaceutical Companies of Johnson & Johnson, Spring House, PA 19477 (United States); National Biotechnology & Pharmaceutical Association, Chicago, IL 60606 (United States); Aguilar, Y. [Tribology, Powder Metallurgy and Processing of Solid Recycled Research Group, Universidad del Valle, Cali (Colombia)

    2015-06-15

    Material surface modification, particularly the deposition of special coatings on the surface of surgical implants, is extensively used in bone tissue engineering applications. β-Tricalcium phosphate/Chitosan (β-TCP/Ch) coatings were deposited on 316L stainless steel (316L SS) substrates by a cathodic electro-deposition technique at different coating compositions. The crystal lattice arrangements were analyzed by X-Ray diffraction (XRD), and the results indicated that the crystallographic structure of β-TCP was affected by the inclusion of the chitosan content. The changes in the surface morphology as a function of increasing chitosan in the coatings via scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed that root-mean square values of the β-TCP/Ch coatings decreased by further increasing chitosan percentage. The elastic–plastic characteristics of the coatings were determined by conducting nanoindentation test, indicating that increase of chitosan percentage is directly related to increase of hardness and elastic modulus of the β-TCP/Ch coatings. Tribological characterization was performed by scratch test and pin-on-disk test to analyze the changes in the surface wear of β-TCP/Ch coatings. Finally, the results indicated an improvement in the mechanical and tribological properties of the β-TCP/Ch coatings as a function of increasing of the chitosan percentage. This new class of coatings, comprising the bioactive components, is expected not only to enhance the bioactivity and biocompatibility, but also to protect the surface of metallic implants against wear and corrosion. - Highlights: • Superficial phenomenon that occurs in tribological surface of β-tricalcium phosphate-chitosan coatings. • Improvement on surface mechanical properties of ceramic-polymeric and response to surface tribological damage. • β-tricalcium phosphate-chitosan coatings that offer highest performance in the biomedical devices.

  9. Determination of physical properties for β-TCP + chitosan biomaterial obtained on metallic 316L substrates

    International Nuclear Information System (INIS)

    Material surface modification, particularly the deposition of special coatings on the surface of surgical implants, is extensively used in bone tissue engineering applications. β-Tricalcium phosphate/Chitosan (β-TCP/Ch) coatings were deposited on 316L stainless steel (316L SS) substrates by a cathodic electro-deposition technique at different coating compositions. The crystal lattice arrangements were analyzed by X-Ray diffraction (XRD), and the results indicated that the crystallographic structure of β-TCP was affected by the inclusion of the chitosan content. The changes in the surface morphology as a function of increasing chitosan in the coatings via scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed that root-mean square values of the β-TCP/Ch coatings decreased by further increasing chitosan percentage. The elastic–plastic characteristics of the coatings were determined by conducting nanoindentation test, indicating that increase of chitosan percentage is directly related to increase of hardness and elastic modulus of the β-TCP/Ch coatings. Tribological characterization was performed by scratch test and pin-on-disk test to analyze the changes in the surface wear of β-TCP/Ch coatings. Finally, the results indicated an improvement in the mechanical and tribological properties of the β-TCP/Ch coatings as a function of increasing of the chitosan percentage. This new class of coatings, comprising the bioactive components, is expected not only to enhance the bioactivity and biocompatibility, but also to protect the surface of metallic implants against wear and corrosion. - Highlights: • Superficial phenomenon that occurs in tribological surface of β-tricalcium phosphate-chitosan coatings. • Improvement on surface mechanical properties of ceramic-polymeric and response to surface tribological damage. • β-tricalcium phosphate-chitosan coatings that offer highest performance in the biomedical devices

  10. Thiolated chitosan-modified PLA-PCL-TPGS nanoparticles for oral chemotherapy of lung cancer

    Science.gov (United States)

    Jiang, Liqin; Li, Xuemin; Liu, Lingrong; Zhang, Qiqing

    2013-02-01

    Oral chemotherapy is a key step towards `chemotherapy at home', a dream of cancer patients, which will radically change the clinical practice of chemotherapy and greatly improve the quality of life of the patients. In this research, three types of nanoparticle formulation from commercial PCL and self-synthesized d-α-tocopheryl polyethylene glycol 1000 succinate (PLA-PCL-TPGS) random copolymer were prepared in this research for oral delivery of antitumor agents, including thiolated chitosan-modified PCL nanoparticles, unmodified PLA-PCL-TPGS nanoparticles, and thiolated chitosan-modified PLA-PCL-TPGS nanoparticles. Firstly, the PLA-PCL-TPGS random copolymer was synthesized and characterized. Thiolated chitosan greatly increases its mucoadhesiveness and permeation properties, thus increasing the chances of nanoparticle uptake by the gastrointestinal mucosa and improving drug absorption. The PLA-PCL-TPGS nanoparticles were found by FESEM that they are of spherical shape and around 200 nm in diameter. The surface charge of PLA-PCL-TPGS nanoparticles was reversed from anionic to cationic after thiolated chitosan modification. The thiolated chitosan-modified PLA-PCL-TPGS nanoparticles have significantly higher level of the cell uptake than that of thiolated chitosan-modified PLGA nanoparticles and unmodified PLA-PCL-TPGS nanoparticles. In vitro cell viability studies showed advantages of the thiolated chitosan-modified PLA-PCL-TPGS nanoparticles over Taxol® in terms of cytotoxicity against A549 cells. It seems that the mucoadhesive nanoparticles can increase paclitaxel transport by opening tight junctions and bypassing the efflux pump of P-glycoprotein. In conclusion, PLA-PCL-TPGS nanoparticles modified by thiolated chitosan could enhance the cellular uptake and cytotoxicity, which revealed a potential application for oral chemotherapy of lung cancer.

  11. Zwitterionic chitosan derivatives for pH-sensitive stealth coating

    OpenAIRE

    Xu, Peisheng; Bajaj, Gaurav; Shugg, Tyler; Van Alstine, William G.; Yeo, Yoon

    2010-01-01

    Zwitterionic chitosan, a chitosan derivative with a unique pH-dependent charge profile, was employed to create a stealth coating on the cationic surface of drug carriers. Zwitterionic chitosans were synthesized by amidation of chitosan with succinic anhydride. The succinic anhydride-conjugated chitosan had an isoelectric point, which could be easily tuned from pH 4.9 to 7.1, and showed opposite charges below and above the isoelectric point. The succinic anhydride-conjugated chitosan was able ...

  12. Chitosan as a starting material for wound healing applications

    OpenAIRE

    Patrulea, Viorica; Ostafe, V.; Borchard, Gerrit; Jordan, Olivier

    2015-01-01

    Chitosan and its derivatives have attracted great attention due to their properties beneficial for application to wound healing. The main focus of the present review is to summarize studies involving chitosan and its derivatives, especially N,N,N-trimethyl-chitosan (TMC), N,O-carboxymethyl-chitosan (CMC) and O-carboxymethyl-N,N,N-trimethyl-chitosan (CMTMC), used to accelerate wound healing. Moreover, formulation strategies for chitosan and its derivatives, as well as their in vitro, in vivo a...

  13. Pharmacokinetics and biodegradation of chitosan in rats

    Science.gov (United States)

    Li, Hui; Jiang, Zhiwen; Han, Baoqin; Niu, Shuyi; Dong, Wen; Liu, Wanshun

    2015-10-01

    Chitosan, an excellent biomedical material, has received a widespread in vivo application. In contrast, its metabolism and distribution once being implanted were less documented. In this study, the pharmacokinetics and biodegradation of fluorescein isothiocyanate (FITC) labeled and muscle implantation administrated chitosan in rats were investigated with fluorescence spectrophotometry, histological assay and gel chromatography. After implantation, chitosan was degraded gradually during its distribution to diverse organs. Among the tested organs, liver and kidney were found to be the first two highest in chitosan content, which was followed by heart, brain and spleen. Urinary excretion was believed to be the major pathway of chitosan elimination, yet 80% of chitosan administered to rats was not trackable in their urine. This indicated that the majority of chitosan was degraded in tissues. In average, the molecular weight of the degradation products of chitosan in diverse organs and urine was found to be <65 kDa. This further confirmed the in vivo degradation of chitosan. Our findings provided new evidences for the intensive and safe application of chitosan as a biomedical material.

  14. Performance of a local open pollinated maize variety and a common hybrid variety under intensive small-scale farming practices

    OpenAIRE

    Norton, J B.; Omondi, E.C.; Ashilenje, Dennis S.

    2014-01-01

    Metadata only record Given that the majority of maize farmers in Kenya are small-scale, improvement in maize production must focus on increased production per unit area. While hybrid maize varieties outperform local open pollinated varieties under conventional farming practices, their relative performance has not been tested under small-scale intensive production practices. A study was conducted in 2013 in Kitale, western Kenya, to evaluate performance of ‘Namba Nane’; a local open pollina...

  15. Sorption characteristics of technetium on crosslinked chitosan from aqueous solutions

    International Nuclear Information System (INIS)

    Removal of radioactive ions from the wastewaters is a huge problem because these ions are extremely dangerous for environment and human health by their high toxicity at very low concentrations and long half lives. These pollutants arise into the wastewaters as a result of different industrial activities like: mining, production of nuclear fuels, laboratory investigations, etc. The methods developed for removal of radioisotopes from wastewaters include: chemical precipitation, ion exchange, membrane-related processes, biological processes and electrochemical techniques. The application of polymer such as chitosan is one of the emerging adsorption methods for removal of dyes and heavy metal ions, even at low concentrations. Chitosan is a type of natural polyaminosaccharide, synthesized from deacetylation of chitin. It is composed of β (1→4) linked 2-amino-2-deoxy-D-glucopyranose units. Chitosan is very sensitive to pH as it can either form gel or dissolve depending on the pH values. To improve chitosan's performance as an adsorbent, cross-linking reagents such as glyoxal, formaldehyde, glutaraldehyde, epichlorohydrin have been used. Cross-linking agents do not only stabilize chitosan in acid solutions so that is becomes insoluble but also enhance its mechanical properties and adsorption capacity. Crosslinked chitosan is suitable for the sorption of radionuclides from aqueous solutions, such as cesium, cobalt, europium, uranium, thorium, technetium, plutonium, and americium due to the presence of amino and hydroxyl groups, which are the active sites. Technetium has no stable isotope in nature, it has essentially all been created by human activities. Among radioactive isotopes, 99Tc has a half-life 2.1·105 years sufficiently long enough to warrant concern and it is produced in the fission of 235U and 239Pu with a relatively high yield of about 6 %. The radionuclide, 99Tc, has been released into the environment during nuclear weapons testing. Since discharges

  16. Chitosan and chitosan/wheat gluten blends : properties of extrudates, solid films and bio-foams

    OpenAIRE

    Chen, Fei

    2015-01-01

    This thesis presents four different studis describing the characteristics and processing opportunities of two widely available biopolymers: chitosan and wheat gluten. The interest in these materials is mainly because they are bio-based and obtained as co- or by-products in the fuel and food sector In the first study, high solids content chitosan samples (60 wt.%) were successfully extruded. Chitosan extrusion has previously been reported but not chitosan extrusion with a high solids content, ...

  17. Chitin, Chitosan, and Glycated Chitosan Regulate Immune Responses: The Novel Adjuvants for Cancer Vaccine

    OpenAIRE

    Xiaosong Li; Min Min; Nan Du; Ying Gu; Tomas Hode; Mark Naylor; Dianjun Chen; Nordquist, Robert E.; Chen, Wei R.

    2013-01-01

    With the development of cancer immunotherapy, cancer vaccine has become a novel modality for cancer treatment, and the important role of adjuvant has been realized recently. Chitin, chitosan, and their derivatives have shown their advantages as adjuvants for cancer vaccine. In this paper, the adjuvant properties of chitin and chitosan were discussed, and some detailed information about glycated chitosan and chitosan nanoparticles was also presented to illustrate the trend for future development.

  18. Nitrate leaching from Silage Maize

    OpenAIRE

    Hansen, Elly Møller; Eriksen, Jørgen

    2009-01-01

    During the last 20 years the area with maize in Denmark has increased dramatically and reached 163,000 ha in 2008. Silage maize is easy to grow, is a suitable fodder for cows and goes well with grass-clover in the diet. This means that silage maize is often found in crop rotations with grass-clover on sandy soils in western Denmark. The ploughing in of grass-clover fields poses a serious risk of increased nitrate leaching on a coarse sandy soil, even when carried out in spring. With increased...

  19. Chitosan adsorption to salivary pellicles

    NARCIS (Netherlands)

    van der Mei, Henderina; Engels, Eefje; de Vries, Jacob; Dijkstra, Rene JB; Busscher, Hendrik

    2007-01-01

    The salivary pellicle is a negatively charged protein film, to which oral bacteria readily adhere. Chitosans are cationic biomolecules with known antimicrobial properties that can be modified in different ways to enhance its antimicrobial activity. Here, we determined the changes in surface chemical

  20. Chitosan and carboxymethyl-chitosan capping ligands: Effects on the nucleation and growth of hydroxyapatite nanoparticles for producing biocomposite membranes.

    Science.gov (United States)

    Dumont, Vitor C; Mansur, Alexandra A P; Carvalho, Sandhra M; Medeiros Borsagli, Fernanda G L; Pereira, Marivalda M; Mansur, Herman S

    2016-02-01

    phosphate phase produced during the co-precipitation aqueous process for both the chitosan and CMC biocomposites. These novel hybrid systems based on chitosan and chitosan-derivatives with nHA composites were non-cytotoxic to a human osteoblast-like model cell line (SAOS) according to MTT in vitro assays. Moreover, the CMC-nHA biocomposites revealed a striking improvement in the cell viability response compared to the CHI-nHA biocomposite, which was attributed to the much higher surface area caused by the refinement of the nanoparticles size. Thus, the results of this study demonstrate that these novel bionanocomposite membranes offer promising perspectives as biomaterials for potential repair and replacement of cartilage and bone tissues. PMID:26652373

  1. Proton play in the formation of low molecular weight chitosan (LWCS) by hydrolyzing chitosan with a carbon based solid acid.

    Science.gov (United States)

    Krishnan, R Akhil; Deshmukh, Pranjal; Agarwal, Siddharth; Purohit, Poorvi; Dhoble, Deepa; Waske, Prashant; Khandekar, Dileep; Jain, Ratnesh; Dandekar, Prajakta

    2016-10-20

    Low molecular weight chitosan (LWCS) constitute a special class of value added chemicals that are primarily obtained from crustacean shells, which are the main water pollutants from crabs and shrimp processing centers. Unlike chitin and chitosan, LWCS possess improved solubility in water and aqueous solutions, making them widely applicable in numerous fields ranging from drug delivery to waste water treatment. Among the methods employed for their production, chemical breakdown by strong liquid acids has yielded good success. However, this method is met with severe concerns arising from the harsh nature of liquid acids, which may corrode the reactors for commercial synthesis, and their limited reusability. The physical methods like ultrasound and microwave are energy intensive in nature, while the enzymatic methods are expensive and offers limited scope for reuse. We have attempted to overcome these problems by employing carbon based solid acid (CSA) for hydrolyzing chitosan to LWCS. CSA can be easily produced using activated carbon, a cost-effective and easily available raw material. Reactions were carried out between chitosan and CSA in a hydrothermal glass reactor and the products, separated by cold centrifugation, were purified and dried. The dried products were characterized for their molecular weight and solubility. Results indicated more than ten-fold decrease in the molecular weight of chitosan and the product exhibited water solubility. The CSA could be used upto four times, without regeneration, to give a consistent quality product. The aqueous solution of resulting LWCS exhibited a pH of 6.03±0.11, as against the acidic pH range of solutions of commercially available LWCS, indicating its suitability for biomedical applications. Our investigation facilitates a 'green approach' that may be employed for commercial production of value added chemicals from waste products of marine industry. PMID:27474584

  2. Preparation and Application of Chitosan Membranes to Filter Silver from X-ray Film Processing Wastes

    Science.gov (United States)

    Nyoman Rupiasih, N.; Rustam Purnomo, Rendra; Sumadiyasa, Made

    2016-04-01

    Chitosan is a natural polysaccharide biopolymer which has been widely used in different processes and applications. Chitosan based membranes have been used in reverse osmosis, gas separation, dialysis and pervaporation. The object of this research was investigating the possibility of chitosan membrane used as a filter for removing silver (Ag) from X-ray film processing wastes. Several of chitosan membranes such as M1, M2, M3 and M4 have been prepared for the purpose and filtration was done using dead-end filtration method. The filtration experiments were performed on a flat sheet membrane using pure water and X-ray film processing wastes as feeds. The analysis of silver concentration has been done by atomic absorption spectrometers (AAS). The results show that chitosan membrane M2 gave the highest filtration coefficient (Rcoeff ) i.e. 99.9%, with the pure water flux (PWF) and product flux (PF) are 2972.56 L/m2h and 1761.18 L/m2h respectively. The rejection coefficient of the membranes decreases with increasing the amount of chitosan, while the pure water flux and product flux are increased. The filtration coefficients show that the chitosan membranes are able to filter silver waste from X-ray film processing wastes with performance dependent on their characteristic such as pores size. This suggests that, chitosan membrane can be used as one method that is safe and friendly environment for recovering silver from X-ray film processing waste to improve the quality of treated to an acceptable quality level.

  3. Flexible bactericidal graphene oxide–chitosan layers for stem cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Mazaheri, M. [Department of Materials Science and Engineering, Sharif University of Technology, PO Box 11365-9466, Tehran (Iran, Islamic Republic of); Akhavan, O., E-mail: oakhavan@sharif.edu [Department of Physics, Sharif University of Technology, PO Box 11155-9161, Tehran (Iran, Islamic Republic of); Institute for Nanoscience and Nanotechnology, Sharif University of Technology, PO Box 14588-89694, Tehran (Iran, Islamic Republic of); Simchi, A. [Department of Materials Science and Engineering, Sharif University of Technology, PO Box 11365-9466, Tehran (Iran, Islamic Republic of); Institute for Nanoscience and Nanotechnology, Sharif University of Technology, PO Box 14588-89694, Tehran (Iran, Islamic Republic of)

    2014-05-01

    Highlights: • Fabrication of flexible graphene oxide–chitosan nanocomposite layers was reported. • The flexibility of the chitosan layers were improved by adding graphene oxide sheets. • The nanocomposite layers with 1.5 wt% graphene oxide content showed yielded flexible and antibacterial surfaces for stem cell proliferation. - Abstract: Graphene oxide (GO)–chitosan composite layers with stacked layer structures were synthesized using chemically exfoliated GO sheets (with lateral dimensions of ∼1 μm and thickness of ∼1 nm), and applied as antibacterial and flexible nanostructured templates for stem cell proliferation. By increasing the GO content from zero to 6 wt%, the strength and elastic modulus of the layers increased ∼80% and 45%, respectively. Similar to the chitosan layer, the GO–chitosan composite layers showed significant antibacterial activity (>77% inactivation after only 3 h) against Staphylococcus aureus bacteria. Surface density of the actin cytoskeleton fibers of human mesenchymal stem cells (hMSCs) cultured on the chitosan and GO(1.5 wt%)–chitosan composite layers was found nearly the same, while it significantly decreased by increasing the GO content to 3 and 6 wt%. Our results indicated that although a high concentration of GO in the chitosan layer (here, 6 wt%) could decelerate the proliferation of the hMSCs on the flexible layer, a low concentration of GO (i.e., 1.5 wt%) not only resulted in biocompatibility but also kept the mechanical flexibility of the self-sterilized layers for high proliferation of hMSCs.

  4. Flexible bactericidal graphene oxide–chitosan layers for stem cell proliferation

    International Nuclear Information System (INIS)

    Highlights: • Fabrication of flexible graphene oxide–chitosan nanocomposite layers was reported. • The flexibility of the chitosan layers were improved by adding graphene oxide sheets. • The nanocomposite layers with 1.5 wt% graphene oxide content showed yielded flexible and antibacterial surfaces for stem cell proliferation. - Abstract: Graphene oxide (GO)–chitosan composite layers with stacked layer structures were synthesized using chemically exfoliated GO sheets (with lateral dimensions of ∼1 μm and thickness of ∼1 nm), and applied as antibacterial and flexible nanostructured templates for stem cell proliferation. By increasing the GO content from zero to 6 wt%, the strength and elastic modulus of the layers increased ∼80% and 45%, respectively. Similar to the chitosan layer, the GO–chitosan composite layers showed significant antibacterial activity (>77% inactivation after only 3 h) against Staphylococcus aureus bacteria. Surface density of the actin cytoskeleton fibers of human mesenchymal stem cells (hMSCs) cultured on the chitosan and GO(1.5 wt%)–chitosan composite layers was found nearly the same, while it significantly decreased by increasing the GO content to 3 and 6 wt%. Our results indicated that although a high concentration of GO in the chitosan layer (here, 6 wt%) could decelerate the proliferation of the hMSCs on the flexible layer, a low concentration of GO (i.e., 1.5 wt%) not only resulted in biocompatibility but also kept the mechanical flexibility of the self-sterilized layers for high proliferation of hMSCs

  5. Chitosan-praseodymium complex for adsorption of fluoride ions from water

    Institute of Scientific and Technical Information of China (English)

    Eny Kusrini; Nofrijon Sofyan; Nyoman Suwartha; Gefin Yesya; Cindy Rianti Priadi

    2015-01-01

    Engineering of chitosan by praseodymium has been investigated to improve the adsorption properties as well as physical characteristics of chitosan. Modification of chitosan changes the original properties of chitosan so that it can be more suitable for ad-sorption of fluoride ions. In this study, chitosan-praseodymium (Chi-Pr) was synthesized by impregnation method. The Chi-Pr com-plex was characterized by scanning electron microscopic-energy dispersive X-ray spectroscopy (SEM-EDX), Fourier transform in-frared (FTIR) and employed as an adsorbent for removal of fluorides ions from water in the batch system. The variables such as con-tact time, concentration of Pr, adsorbent dose, initial concentration of fluoride ions, and competitor anions were studied. The adsorp-tion efficiency of fluoride ions (η) with increasing Pr loading into chitosan (5 wt.%, 10 wt.%, 15 wt.%, 20 wt.% and 25 wt.%) were 35.5%, 56.1%, 72.0%, 68.5% and 62.5%, respectively. The Chi-Pr (15 wt.%) complex had the highest fluoride removal efficiency (72.0%). The experimental data fitted well to the Langmuir isotherm with maximum adsorption capacity (qmax) of 15.87 mg/g and an equilibrium constant (kL) of 0.15 mg. Kinetic study revealed that the adsorption of fluoride ions from water followed pseudo-second-order model with a maximum adsorption capacity (q2) of 8.20 mg/g and a rate constant (k2) of 0.01 g/mg·min. Ad-sorption efficiency of fluoride ions in the simulated drinking water was diminished with the changes in pH levels. The presence of Pr3+in chitosan increased chitosan's performance as an adsorbent for adsorption of fluoride ions.

  6. In vitro corrosion behavior and cytotoxicity property of magnesium matrix composite with chitosan coating

    Institute of Scientific and Technical Information of China (English)

    戴翌龙; 余琨; 陈良建; 陈畅; 乔雪岩; 颜阳

    2015-01-01

    Mg-6%Zn-10%β-Ca3(PO4)2 composite was prepared through powder metallurgy methods with different chitosan coatings on its surface. The properties of the chitosan coatings on the surface of Mg-6%Zn-10%β-Ca3(PO4)2 composite, such as the adhesion ability, the corrosion behavior and the cytotoxicity properties, were investigated, and the microstructure of the chitosan coating was observed by scanning electron microscope (SEM). The results show that chitosan coating improves the corrosion resistance of the magnesium composite specimens significantly. Mg-6%Zn-10%β-Ca3(PO4)2 composite specimens exhibit good corrosion resistance and low pH values in simulated body fluid (SBF) at 37 °C in the immersion test with 7-layer chitosan coating whose relative molecular mass is 30×104 Da. The cytotoxicity tests indicate that Mg-6%Zn-10%β-Ca3(PO4)2 with chitosan coating is nontoxic with a cytotoxicity grade of zero against L-929 cells, which is better than that of uncoated composites.

  7. Fabrication, nanomechanical characterization, and cytocompatibility of gold-reinforced chitosan bio-nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Nimitt G. [Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, NY, 13699 (United States); Materials Science and Engineering PhD Program, Clarkson University, Potsdam, NY, 13699 (United States); Kumar, Ajeet [Center for Advanced Materials Processing, Clarkson University, Potsdam, NY, 13699 (United States); Jayawardana, Veroni N. [Department of Mathematics, Clarkson University, Potsdam, NY, 13699 (United States); Woodworth, Craig D. [Department of Biology, Clarkson University, Potsdam, NY, 13699 (United States); Yuya, Philip A., E-mail: pyuya@clarkson.edu [Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, NY, 13699 (United States)

    2014-11-01

    Chitosan, a naturally derived polymer represents one of the most technologically important classes of active materials with applications in a variety of industrial and biomedical fields. Gold nanoparticles (∼ 32 nm) were synthesized via a citrate reduction method from chloroauric acid and incorporated in Chitosan matrix. Bio-nanocomposite films with varying concentrations of gold nanoparticles were prepared through solution casting process. Uniform distribution of gold nanoparticles was achieved throughout the chitosan matrix and was confirmed with SEM. Synthesis outcomes and prepared nanocomposites were characterized using SEM, TEM, EDX, SAED, UV–vis, XRD, DLS, and Zeta potential for their physical, morphological and structural properties. Nanoscale properties of materials under the influence of temperature were characterized through nanoindentation techniques. From quasi-static nanoindentation, it was observed that hardness and reduced modulus of the nanocomposites were increased significantly in direct proportion to the gold nanoparticle concentration. Gold nanoparticle concentration also showed positive impact on storage modulus and thermal stability of the material. The obtained films were confirmed to be biocompatible by their ability to support growth of human cells in vitro. In summary, the results show enhanced mechanical properties with increasing gold nanoparticle concentration, and provide better understanding of the structure–property relationships of such biocompatible materials for potential biomedical applications. - Highlights: • We fabricated gold reinforced chitosan nanocomposite for biomedical applications. • Gold nanoparticles significantly enhanced nanomechanical properties of chitosan. • Nanocomposite films supported growth of human cells in vitro. • Gold nanoparticles significantly improved cell proliferation on chitosan films.

  8. Effects of chitosan-oil coating on blue mold disease and quality attributes of jujube fruits.

    Science.gov (United States)

    Xing, Yage; Xu, Qinglian; Che, Zhenming; Li, Xihong; Li, Wenting

    2011-08-01

    The effects of chitosan coating enriched with cinnamon oil on blue mold disease and quality attributes were investigated. In the in vitro experiment, the results demonstrated that the antifungal activity against P. citrinum improved with increasing concentration of chitosan or cinnamon oil. In the in vivo study, chitosan-oil treatments significantly reduced fungal decay caused by P. citrinum and all compounds with cinnamon oil at 2.0% showed complete control of the growth of P. citrinum on wound-inoculated fruits. High chitosan-oil concentrations correlated with low disease incidence regardless of storage temperature. Treatments of chitosan-oil coating also inhibited the activity of polyphenol oxidase and maintained vitamin C and phenolic compounds in wounded jujube fruits. Results suggested that the effect of chitosan coating (1.0%) enriched with cinnamon oil (0.75%) on blue mold in jujube fruits may be associated with fungitoxic properties against the pathogen and the elicitation of biochemical defense responses in fruits. PMID:21837310

  9. Chitosan enhances parasitism of Meloidogyne javanica eggs by the nematophagous fungus Pochonia chlamydosporia.

    Science.gov (United States)

    Escudero, Nuria; Ferreira, Sebastião R; Lopez-Moya, Federico; Naranjo-Ortiz, Miguel A; Marin-Ortiz, Ana I; Thornton, Christopher R; Lopez-Llorca, Luis V

    2016-04-01

    Pochonia chlamydosporia (Pc), a nematophagous fungus and root endophyte, uses appressoria and extracellular enzymes, principally proteases, to infect the eggs of plant parasitic nematodes (PPN). Unlike other fungi, Pc is resistant to chitosan, a deacetylated form of chitin, used in agriculture as a biopesticide to control plant pathogens. In the present work, we show that chitosan increases Meloidogyne javanica egg parasitism by P. chlamydosporia. Using antibodies specific to the Pc enzymes VCP1 (a subtilisin), and SCP1 (a serine carboxypeptidase), we demonstrate chitosan elicitation of the fungal proteases during the parasitic process. Chitosan increases VCP1 immuno-labelling in the cell wall of Pc conidia, hyphal tips of germinating spores, and in appressoria on infected M. javanica eggs. These results support the role of proteases in egg parasitism by the fungus and their activation by chitosan. Phylogenetic analysis of the Pc genome reveals a large diversity of subtilisins (S8) and serine carboxypeptidases (S10). The VCP1 group in the S8 tree shows evidence of gene duplication indicating recent adaptations to nutrient sources. Our results demonstrate that chitosan enhances Pc infectivity of nematode eggs through increased proteolytic activities and appressoria formation and might be used to improve the efficacy of M. javanica biocontrol. PMID:27020158

  10. Fabrication, nanomechanical characterization, and cytocompatibility of gold-reinforced chitosan bio-nanocomposites

    International Nuclear Information System (INIS)

    Chitosan, a naturally derived polymer represents one of the most technologically important classes of active materials with applications in a variety of industrial and biomedical fields. Gold nanoparticles (∼ 32 nm) were synthesized via a citrate reduction method from chloroauric acid and incorporated in Chitosan matrix. Bio-nanocomposite films with varying concentrations of gold nanoparticles were prepared through solution casting process. Uniform distribution of gold nanoparticles was achieved throughout the chitosan matrix and was confirmed with SEM. Synthesis outcomes and prepared nanocomposites were characterized using SEM, TEM, EDX, SAED, UV–vis, XRD, DLS, and Zeta potential for their physical, morphological and structural properties. Nanoscale properties of materials under the influence of temperature were characterized through nanoindentation techniques. From quasi-static nanoindentation, it was observed that hardness and reduced modulus of the nanocomposites were increased significantly in direct proportion to the gold nanoparticle concentration. Gold nanoparticle concentration also showed positive impact on storage modulus and thermal stability of the material. The obtained films were confirmed to be biocompatible by their ability to support growth of human cells in vitro. In summary, the results show enhanced mechanical properties with increasing gold nanoparticle concentration, and provide better understanding of the structure–property relationships of such biocompatible materials for potential biomedical applications. - Highlights: • We fabricated gold reinforced chitosan nanocomposite for biomedical applications. • Gold nanoparticles significantly enhanced nanomechanical properties of chitosan. • Nanocomposite films supported growth of human cells in vitro. • Gold nanoparticles significantly improved cell proliferation on chitosan films

  11. In vitro and in vivo Characterization of Homogeneous Chitosan-based Composite Scaffolds

    Institute of Scientific and Technical Information of China (English)

    LI Hong; ZHOU Changren; ZHU Minying; TIAN Jinhuan; RONG Jianhua

    2012-01-01

    With a homogeneous distribution of hydroxyapatite (HAP) crystals in polymer matrix,composite scaffolds chitosan/HAP and chitosan/collagen/HAP were fabricated in the study.XRD,SEM and EDX were used to characterize their components and structure,in vitro cell culture and in vivo animal tests were used to evaluate their biocompatibility.HAP crystals with rod-like shape embeded in chitosan scaffold,while HAP fine-granules bond with collagen/chitosan scaffold compactly.A homogenous distribution of Ca and P elements both in chitosan/HAP scaffold and chitosan/collagen/HAP scaffold was defined by EDX pattern.The presence of collagen brought a more homogenous distribution of HAP due to its higher ability to induce HAP precipitation.The results of in vitro cell culture showed that the composite's biocompatibility was enhanced by the homogenous distribution of HAP.In vivo animal studies showed that the in vivo biodegradation was effectively improved by the addition of HAP and collagen,and was less influenced by the homogeneous distribution of HAP when compared with a concentrated distribution one.The composite scaffolds with a homogeneous HAP distribution would be excellent alternative scaffolds for bone tissue engineering.

  12. Chitosan Modification and Pharmaceutical/Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Jiali Zhang

    2010-06-01

    Full Text Available Chitosan has received much attention as a functional biopolymer for diverse applications, especially in pharmaceutics and medicine. Our recent efforts focused on the chemical and biological modification of chitosan in order to increase its solubility in aqueous solutions and absorbability in the in vivo system, thus for a better use of chitosan. This review summarizes chitosan modification and its pharmaceutical/biomedical applications based on our achievements as well as the domestic and overseas developments: (1 enzymatic preparation of low molecular weight chitosans/chitooligosaccharides with their hypocholesterolemic and immuno-modulating effects; (2 the effects of chitin, chitosan and their derivatives on blood hemostasis; and (3 synthesis of a non-toxic ion ligand—D-Glucosaminic acid from Oxidation of D-Glucosamine for cancer and diabetes therapy.

  13. Preparation and characterization of crosslinked chitosan-based nanofibers

    Institute of Scientific and Technical Information of China (English)

    Ying Shan Zhou; Dong Zhi Yang; Jun Nie

    2007-01-01

    Crosslinked chitosan-based nanofibers were successfully prepared via electrospinning technique with heat mediated chemical crosslinking followed. The structure, morphology and mechanical property of nanofibers were characterized by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), Instron machine, respectively. The results showed that, nanofibers exhibited a smooth surface and regular morphology, and tensile strength of nanofibers improved with increasing of triethylene glycol dimethacrylate (TEGDMA) content.

  14. Application of Ferriferous Oxide Modified by Chitosan in Gene Delivery

    OpenAIRE

    Yu Kuang; Tun Yuan; Zhongwei Zhang; Mingyuan Li; Yuan Yang

    2012-01-01

    New approaches to improve the traditional gene carriers are still required. Here we explore Fe3O4 modified with degradable polymers that enhances gene delivery and target delivery using permanent magnetic field. Two magnetic Fe3O4 nanoparticles coated with chitosan (CTS) and polyethylene glycol (PEG) were synthesized by means of controlled chemical coprecipitation. Plasmid pEGFP was encapsulated as a reported gene. The ferriferous oxide complexes were approximately spherical; surface charge o...

  15. Innovative Composite Films of Chitosan, Methylcellulose, and Nanoparticles

    OpenAIRE

    Mura, Stefania; Corrias, Francesco; Stara, Giuseppe; Piccinini, Massimo; Secchi, Nicola; Marongiu, Daniela; Innocenzi, Plinio; Irudayaraj, Joseph; Greppi, Gian F.

    2011-01-01

    Plastic is readily available and inexpensive, so it is becoming the main material for packaging. Unfortunately plastics do not biodegrade and, if reduced in small pieces, contaminate soil and waterways. In the present work, natural films composed of chitosan, methylcellulose, and silica (SiO(2)) nanoparticles (NPs) were developed as new packaging materials. The effect of the incorporation of NPs into the polymeric film matrix was evaluated. An excellent improvement of the mechanical propertie...

  16. Covalently Bonded Chitosan on Graphene Oxide via Redox Reaction

    OpenAIRE

    Castaño, Víctor M; Carlos Velasco-Santos; Miguel de Icaza; Gonzalo Martínez-Barrera; Karina Bustos-Ramírez; Ana L. Martínez-Hernández

    2013-01-01

    Carbon nanostructures have played an important role in creating a new field of materials based on carbon. Chemical modification of carbon nanostructures through grafting has been a successful step to improve dispersion and compatibility in solvents, with biomolecules and polymers to form nanocomposites. In this sense carbohydrates such as chitosan are extremely valuable because their functional groups play an important role in diversifying the applications of carbon nanomaterials. This paper ...

  17. Breeding of maize types with specific traits at the Maize Research Institute, Zemun Polje

    Directory of Open Access Journals (Sweden)

    Pajić Zorica

    2007-01-01

    Full Text Available Maize is primarily grown as an energy crop, but the use of different specific versions, such as high-oil maize, high-lysine maize, waxy maize, white-seeded maize, popping maize and sweet maize, is quite extensive. Speciality maize, due to its traits and genetic control of these traits, requires a particular attention in handling breeding material during the processes of breeding. It is especially related to prevention of uncontrolled pollination. In order to provide successful selection for a certain trait, the following specific procedures in evaluation of the trait are necessary: the estimation of a popping volume and flake quality in popping maize; the determination of sugars and harvest maturity in sweet maize; the determination of oil in selected samples of high-oil maize types, and so forth. Breeding programmes for speciality maize, except high-amylose maize, have been implemented at the Maize Research Institute, Zemun Polje, Belgrade, for the last 45 years. A great number of high-yielding sweet maize hybrids, popping maize, high-oil and high-lysine, flint and white-seeded maize hybrids were developed during this 45-year period. Auspicious selection and breeding for these traits is facilitated by the abundant genetic variability and technical and technological possibilities necessary for successful selection.

  18. Effect of winter maize-based intercropping systems on maize yield, associated weeds and economic efficiency

    Directory of Open Access Journals (Sweden)

    Akhilesh Mishra

    2014-02-01

    Full Text Available A field experiment was conducted during winter seasons of 2003-04 and 2004-05 at Kanpur, India to study the effect of winter maize (Zea mays L. based intercropping systems on maize yield, associated weeds and economics under irrigated condition of central Uttar Pradesh. Thirteen maize-based cropping systems such as maize sole, potato (Solanum tuberosum L. sole, mustard [Brassica juncea (L. Czernj. & Cosson] sole, toria (Brassica campestris var. toria sole, pea (Pisum sativum L. sole, linseed (Linum usitatissimum L. sole, wheat (Triticum aestivum L. mend. Fiori and Paol. sole, maize + potato (1:1,maize + mustard (1:1, maize + toria (1:2, maize + pea (1:2, maize + linseed (1:2 and maize + toria (1:2, were tested in randomized block design with three replications. Maize + potato system recorded higher yield attributes and grain yield of maize followed by maize + pea than sole stand of maize. potato was showed most compatible intercrop planted with winter maize as it gave higher maize-equivalent yield, land-equivalent ratio, productivity, monetary returns and lowered weed population, weed dry-biomass and highest weed-control efficiency under irrigated conditions of central Uttar Pradesh. Pea was the next best intercrop with winter maize.

  19. In Vitro Degradation of Polyglycolide/Chitosan Hybrid Braids

    Institute of Scientific and Technical Information of China (English)

    YUAN Xiaoyan; ZHANG Qingwei; WANG Yonglin; YAO Kangde

    2005-01-01

    Hybrid braids of polyglycolide (PGA) and chitosan were prepared by the three-yarn braiding method from PGA and chitosan fiber bundles. These braids were in vitro degraded by incubating them in phosphate buffered saline (PBS) at pH 7.4 and 37 ℃ for 5 weeks. Results suggested that PGA/chitosan hybrid braids degraded significantly. Scanning electron micrographs showed that chitosan fibers in the PGA/chitosan hybrid braid with about 750% PGA in weight (PGA75/chitosan) were shaped into gel-like after 5 weeks, but those in the hybrid braid with about 250% PGA in weight (PGA25/chitosan) did not change. After 5 weeks, the ultimate tensile loads of PGA and PGA75/chitosan braids lost almost completely, but those of chitosan and PGA25/chitosan braids remained around 14 N. The PGA/chitosan hybrid braids with higher initial ultimate tensile load would have potential applications in tendon/ligament tissue reconstruction.

  20. Synthesis, characterization and radiation processing of carboxymethyl-chitosan

    International Nuclear Information System (INIS)

    Chitosan is natural polymer derived from chitin, a polysaccharide found in the exoskeleton of shrimps, crabs, fungi and others. Chitosan is a naturally occurring substance that is chemically similar to cellulose. Chitosan possesses a positive ionic charge give ability to chemically bond with negatively charged fats. Chitosan is soluble in organic acid but insoluble in water. Carboxymethyl-chitosan (cm-chitosan) is a derivative of chitosan which is water-soluble was then prepared by carboxymethylation process of chitosan produced from local shrimp shell. A simple method for synthesis of cm-chitosan has been developed at 55 degree C in aqueous sodium hydroxide / propanol with chloroacetic acid (CAA) or sodium chloroacetate salt (SCA). The modification of chitosan to water-soluble chitosan can be used in hydrogel as anti-bacterial and anti-fungal agent, and it overcome the problem of bad smell using organic acid. (Author)

  1. Radiation processing of chitosan derivative and its characteristics

    International Nuclear Information System (INIS)

    Chitosan is natural polymer derived from chitin, a polysaccharide found in the exoskeleton of shrimps, crabs, fungi and others. Chitosan is a naturally occurring substance that is chemically similar to cellulose. Chitosan possesses a positive ionic charge give ability to chemically bond with negatively charged fats. Chitosan is soluble in organic acid but insoluble in water. Carboxymethyl-chitosan (cm-chitosan) is a derivative of chitosan which is water-soluble was then prepared by a carboxymethylation process of chitosan produced from local shrimp shell. A simple method for synthesis of cm-chitosan has been developed at 55 degree C in aqueous sodium hydroxide / propanol with chloroacetic acid (CAA) or sodium chloroacetate salt (SCA). The modification of chitosan to water-soluble chitosan can be used in hydrogel as anti-bacterial agent and it overcome the problem of bad smell using acetic acid. (Author)

  2. ADSORPTION OF LDL ON THE MODIFIED CHITOSAN

    Institute of Scientific and Technical Information of China (English)

    LIUManying; ZHAOLirui; 等

    2000-01-01

    In this paper,the selective adsorption of LDL on chitosan modified with PEG and Asp.was studied.The adsorption rate of LDL and HDL on the double modified chitosan was 57% and 12% respoectively,The results shown that the double modified chitosan can be used a adsorbent for selective binding to LDL,this work may help to develop functional columns for hemoperfusion.

  3. Effect of Chitosan Properties on Immunoreactivity

    OpenAIRE

    Sruthi Ravindranathan; Bhanu prasanth Koppolu; Smith, Sean G.; Zaharoff, David A

    2016-01-01

    Chitosan is a widely investigated biopolymer in drug and gene delivery, tissue engineering and vaccine development. However, the immune response to chitosan is not clearly understood due to contradicting results in literature regarding its immunoreactivity. Thus, in this study, we analyzed effects of various biochemical properties, namely degree of deacetylation (DDA), viscosity/polymer length and endotoxin levels, on immune responses by antigen presenting cells (APCs). Chitosan solutions fro...

  4. Monitoring and evaluation of need for nitrogen fertilizer topdressing for maize leaf chlorophyll readings and the relationship with grain yield

    Directory of Open Access Journals (Sweden)

    Maria Anita Gonçalves da Silva

    2011-08-01

    Full Text Available The study was carried out for two years in maize in succession to the wheat using no tillage system in a distroferric Red Latosol (Hapludox. Methods of management nitrogen fertilizer (120 kg ha-1 with ammonium sulphate were studied; the fertilizer was applied in maize sowing or in maize topdressing, and N with previous application in wheat sowing. In addition, leaf chlorophyll reading was used as an indicator for the need for topdressed nitrogen fertilizer. Nitrogen supply index (NSI was shown to be effective at predicting need for topdressed nitrogen fertilizer for maize. The application of N improved the yield of the maize independent of the management system. The flowering stage was carried out at the appropriate time in order to estimate the nitrogen nutrition state and yield of maize using the relative chlorophyll level (RIC.

  5. Specific optical rotation indicatrices of chitosan films

    Science.gov (United States)

    Rudenko, Darya A.; Shipovskaya, Anna B.

    2016-04-01

    The optical activity of chitosan films in the forms of polysalt (chitosan acetate) and polybase was studied. The specific optical rotation [α] of all our films was negative. The absolute values of [α] of polybasic chitosan films was by an order of magnitude higher than that for polysalt films. A dependence of [α] on the orientation angle of the sample relative to the direction of the polarization vector of the incident light beam in the plane perpendicular to this beam was established. Specific optical rotation indicatrices of the chitosan films of both chemical forms were plotted.

  6. Characterization of multilayered and composite edible films from chitosan and beeswax.

    Science.gov (United States)

    Velickova, Elena; Winkelhausen, Eleonora; Kuzmanova, Slobodanka; Moldão-Martins, Margarida; Alves, Vitor D

    2015-03-01

    Chitosan-based edible films were prepared and subjected to cross-linking reactions using sodium tripolyphosphate and/or to beeswax coating on both films interfaces. In addition, chitosan-beeswax emulsion-based films were produced. The goal of these modifications of the chitosan films was the improvement of their barrier to water vapor and to decrease their affinity to liquid water maintaining or improving the mechanical and optical properties of the original chitosan films. The cross-linking with tripolyphosphate decreased both the water vapor permeability and the water absorption capacity to about 55% and 50% of that of the original chitosan films, respectively. However, there was an increase in the films stiffness, revealed by the increased Young modulus from 42 kPa up to 336 kPa. The multilayered wax-chitosan-wax films exhibited a similar improvement of the barrier properties to water vapor, with the advantage of maintaining the mechanical properties of the original chitosan films. However, these wax-coated films showed a higher water absorption capacity, which is believed to be a consequence of water entry into small pores between the film and the wax layers. Regarding the film samples subjected to cross-linking and further coating with beeswax, a similar behavior as the uncoated cross-linked films was observed. The emulsion-based composite films were characterized by a substantial decrease of the water vapor permeability (40%), along with a decrease in their stiffness. Regarding the optical properties, all films presented a yellowish color with similar values of lightness, chroma, and hue. PMID:24285830

  7. Controllable degradation of medical magnesium by electrodeposited composite films of mussel adhesive protein (Mefp-1) and chitosan.

    Science.gov (United States)

    Jiang, Ping-Li; Hou, Rui-Qing; Chen, Cheng-Dong; Sun, Lan; Dong, Shi-Gang; Pan, Jin-Shan; Lin, Chang-Jian

    2016-09-15

    To control the degradation rate of medical magnesium in body fluid environment, biocompatible films composed of Mussel Adhesive Protein (Mefp-1) and chitosan were electrodeposited on magnesium surface in cathodic constant current mode. The compositions and structures of the films were characterized by atomic force microscope (AFM), scanning electron microscope (SEM) and infrared reflection absorption spectroscopy (IRAS). And the corrosion protection performance was investigated using electrochemical measurements and immersion tests in simulated body fluid (Hanks' solution). The results revealed that Mefp-1 and chitosan successfully adhered on the magnesium surface and formed a protective film. Compared with either single Mefp-1 or single chitosan film, the composite film of chitosan/Mefp-1/chitosan (CPC (chitosan/Mefp-1/chitosan)) exhibited lower corrosion current density, higher polarization resistance and more homogenous corrosion morphology and thus was able to effectively control the degradation rate of magnesium in simulated body environment. In addition, the active attachment and spreading of MC3T3-E1 cells on the CPC film coated magnesium indicated that the CPC film was significantly able to improve the biocompatibility of the medical magnesium. PMID:27309944

  8. Fish gelatin combined with chitosan coating inhibits myofibril degradation of golden pomfret (Trachinotus blochii) fillet during cold storage.

    Science.gov (United States)

    Feng, Xiao; Bansal, Nidhi; Yang, Hongshun

    2016-06-01

    Coating of gelatin and chitosan can improve fish fillet's quality, but the mechanism is not clear. Chitosan/gelatin coatings significantly prevented deterioration of golden pomfret fillet at 4 °C. Chitosan with 7.2% gelatin group showed the best effect on preserving the length of myofibril, which remained greater than 15 μm at day 17 of storage, while for control, chitosan and chitosan combined with 3.6% gelatin group, it was 5.03, 10.04 and 9.02 μm, respectively. The MALDI-TOF MS result revealed that the coatings slowed down the protein deterioration of fillet. On days 13 and 17, the myosin light chain and myoglobin in control group degraded, while the two proteins still existed in chitosan/gelatin coated groups. Overall, the chitosan with 7.2% gelatin coating had the best effect on preserving fillet's quality during storage. The coating may exert its protective effect via inhibiting myofibril degradation within fillet. PMID:26830590

  9. Photonic monitoring of chitosan nanostructured alginate microcapsules for drug release

    Science.gov (United States)

    Khajuria, Deepak Kumar; Konnur, Manish C.; Vasireddi, Ramakrishna; Roy Mahapatra, D.

    2015-02-01

    By using a novel microfluidic set-up for drug screening applications, this study examines delivery of a novel risedronate based drug formulation for treatment of osteoporosis that was developed to overcome the usual shortcomings of risedronate, such as its low bioavailability and adverse gastric effects. Risedronate nanoparticles were prepared using muco-adhesive polymers such as chitosan as matrix for improving the intestinal cellular absorption of risedronate and also using a gastric-resistant polymer such as sodium alginate for reducing the gastric inflammation of risedronate. The in-vitro characteristics of the alginate encapsulated chitosan nanoparticles are investigated, including their stability, muco-adhesiveness, and Caco-2 cell permeability. Fluorescent markers are tagged with the polymers and their morphology within the microcapsules is imaged at various stages of drug release.

  10. Development of novel guava puree films containing chitosan nanoparticles.

    Science.gov (United States)

    Lorevice, Marcos V; de Moura, Márcia R; Aouada, Fauze A; Mattoso, Luiz H C

    2012-03-01

    One of the overall goals of industries is to use packages that do not cause environmental problems at disposal time, but that have the same properties as the conventional ones. The goal of this study is to synthesize edible films based on hydroxypropyl methylcellulose (HPMC) with guava puree and chitosan (CS) nanoparticles. This was divided into two stages, the first is the synthesis of chitosan nanoparticles and the second is the production of the films. For the nanoparticles, average size and zeta potential measurements were performed. The characterizations of mechanical and thermal properties, solubility and water vapor permeability tests were conducted in the films. It was observed that when the nanoparticles were added to HPMC and guava puree films, they improved their mechanical and thermal properties, as well as decreased the films solubility and permeability. The potential application of the films prepared would be in edible films with flavor and odor to extend the shelf life of products. PMID:22755113

  11. Nitrogen/Sulfur-Codoped Carbon Materials from Chitosan for Supercapacitors

    Science.gov (United States)

    Li, Mei; Han, Xianlong; Chang, Xiaoqing; Yin, Wenchao; Ma, Jingyun

    2016-08-01

    d-Methionine and chitosan have been used for fabrication of nitrogen/sulfur-codoped carbon materials by a hydrothermal process followed by carbonization at 750°C for 3 h. The as-prepared carbon materials showed enhanced electrochemical performance, combining electrical double-layer capacitance with pseudocapacitance owing to the doping with sulfur and nitrogen. The specific capacitance of the obtained carbon material reached 135 F g-1 at current density of 1 A g-1, which is much higher than undoped chitosan (67 F g-1). The capacitance retention of the carbon material was almost 97.2% after 5000 cycles at current density of 1 A g-1. With such improved electrochemical performance, the nitrogen/sulfur-codoped carbon material may have promising potential for use in energy-storage electrodes of supercapacitors.

  12. Preparation and antibacterial activity of quaternized chitosan with iodine

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Yang; Xie, Linlin; Sai, Mingze; Xu, Ningning; Ding, Derun, E-mail: dingderun@sues.edu.cn

    2015-03-01

    Chitosan (CTS) is a natural polymer with active groups such as –NH{sub 2} which can be functionalized to introduce new positively charged N-atoms and protonated amino group for better use. In this study, to improve the stability of iodine, a novel complex (CTS–CTA–I{sub 2}) was prepared by mixing N-(2-hydroxy) propyl-3-trimethylammonium chitosan chloride (CTS–CTA) with iodine in ethanol solution. The CTS–CTA–I{sub 2} was characterized by Fourier transform infrared spectra (FTIR), Ultraviolet and visible (UV–vis) spectra and thermal gravimetric analysis (TG). Besides, the interaction of iodine with CTS–CTA was also studied. The mole ratio of CTS–CTA with iodine was measured by iodometric titration method and the max mole ratio of CTS–CTA with iodine was 1:1.33. The antimicrobial activity of CTS, CTS–CTA and CTS–CTS–I{sub 2} complexes was investigated against Escherichia coli and Staphylococcus aureus and the antibacterial property of CTS–CTA–I{sub 2} was superior to CTS–CTA. - Highlights: • We prepared a novel iodine complex based on chitosan. • The CTS–CTA–I{sub 2} complex improved the stability of iodine. • The max mole ratio of CTS–CTA with iodine was 1:1.33. • The CTS–CTA–I{sub 2} complex showed significant antibacterial activity.

  13. Oxidized Xanthan Gum and Chitosan as Natural Adhesives for Cork

    Directory of Open Access Journals (Sweden)

    Diana Paiva

    2016-07-01

    Full Text Available Natural cork stopper manufacturing produces a significant amount of cork waste, which is granulated and combined with synthetic glues for use in a wide range of applications. There is a high demand for using biosourced polymers in these composite materials. In this study, xanthan gum (XG and chitosan (CS were investigated as possible natural binders for cork. Xanthan gum was oxidized at two different aldehyde contents as a strategy to improve its water resistance. This modification was studied in detail by 1H and 13C nuclear magnetic resonance (NMR, and the degree of oxidation was determined by the hydroxylamine hydrochloride titration method. The performance of the adhesives was studied by tensile tests and total soluble matter (TSM determinations. Xanthan gum showed no water resistance, contrary to oxidized xanthan gum and chitosan. It is hypothesized that the good performance of oxidized xanthan gum is due to the reaction of aldehyde groups—formed in the oxidation process—with hydroxyl groups on the cork surface during the high temperature drying. Combining oxidized xanthan gum with chitosan did not yield significant improvements.

  14. Synthesis and characterization of a novel chitosan/montmorillonite/hydroxyapatite nanocomposite for bone tissue engineering

    International Nuclear Information System (INIS)

    Recently, biopolymer-based nanocomposites have been replacing synthetic polymer composites for various biomedical applications. This is often because of the biocompatible and biodegradable behavior of natural polymers. Several studies have been reported pertaining to the synthesis and characterization of chitosan(chi)/montmorillonite(MMT) and chitosan (chi)/hydroxyapatite (HAP) for tissue engineering applications. In the present work, a biopolymer-based novel nanocomposite chitosan/montmorillonite (MMT)/hydroxyapatite (HAP) was developed for biomedical applications. The composite was prepared from chitosan, unmodified MMT and HAP precipitate in aqueous media. The properties of the composites were investigated using x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM) and thermogravimetric analysis (TGA). Nanomechanical properties were measured using nanoindentation. Cell culture experiments were also conducted in order to ascertain the biocompatibility of the composite. The XRD results indicate that an intercalated structure was formed with an increase in d-spacing of montmorillonite. FTIR studies provide the evidence of molecular interaction among the three different constituents of the composite. AFM images show well-distributed nanoparticles in the chitosan matrix. The composites also exhibit a significant enhancement in nanomechanical property as compared to pure chitosan as well as the chi/HAP and chi/MMT composites. The TGA results indicate that an intercalated nanocomposite was formed with improved thermal properties even compared to chi/MMT composites. The results of cell culture experiments show that the composite is biocompatible and has a better cell proliferation rate compared to chi/HAP composites. This work represents the design of a novel clay-chitosan-hydroxyapatite composite with improved mechanical properties that has potential applications in bone tissue engineering

  15. Chitosan-Iron Oxide Coated Graphene Oxide Nanocomposite Hydrogel: A Robust and Soft Antimicrobial Biofilm.

    Science.gov (United States)

    Konwar, Achyut; Kalita, Sanjeeb; Kotoky, Jibon; Chowdhury, Devasish

    2016-08-17

    We report a robust biofilm with antimicrobial properties fabricated from chitosan-iron oxide coated graphene oxide nanocomposite hydrogel. For the first time, the coprecipitation method was used for the successful synthesis of iron oxide coated graphene oxide (GIO) nanomaterial. After this, films were fabricated by the gel-casting technique aided by the self-healing ability of the chitosan hydrogel network system. Both the nanomaterial and the nanocomposite films were characterized by techniques such as scanning electron microscopy, FT-IR spectroscopy, X-ray diffraction, and vibrating sample magnetometry. Measurements of the thermodynamic stability and mechanical properties of the films indictaed a significant improvement in their thermal and mechanical properties. Moreover, the stress-strain profile indicated the tough nature of the nanocomposite hydrogel films. These improvements, therefore, indicated an effective interaction and good compatibility of the GIO nanomaterial with the chitosan hydrogel matrix. In addition, it was also possible to fabricate films with tunable surface properties such as hydrophobicity simply by varying the loading percentage of GIO nanomaterial in the hydrogel matrix. Fascinatingly, the chitosan-iron oxide coated graphene oxide nanocomposite hydrogel films displayed significant antimicrobial activities against both Gram-positive and Gram-negative bacterial strains, such as methicillin-resistant Staphylococcus aureus, Staphylococcus aureus, and Escherichia coli, and also against the opportunistic dermatophyte Candida albicans. The antimicrobial activities of the films were tested by agar diffusion assay and antimicrobial testing based on direct contact. A comparison of the antimicrobial activity of the chitosan-GIO nanocomposite hydrogel films with those of individual chitosan-graphene oxide and chitosan-iron oxide nanocomposite films demonstrated a higher antimicrobial activity for the former in both types of tests. In vitro hemolysis

  16. Genetic relationships and structure among open pollinated maize varieties adapted to eastern and southern Africa using microsatellite markers

    Science.gov (United States)

    The International Maize and Wheat Improvement Center (CIMMYT), in collaboration with the national agricultural systems (NARS) in sub-Saharan Africa (SSA), have developed various stress-tolerant and more nutritious open-pollinated varieties (OPVs) of maize that are suitable for smallholder farmers’ g...

  17. Bioavailability of iron, zinc, folic acid, and vitamin A from fortified maize.

    Science.gov (United States)

    Moretti, Diego; Biebinger, Ralf; Bruins, Maaike J; Hoeft, Birgit; Kraemer, Klaus

    2014-04-01

    Several strategies appear suitable to improve iron and zinc bioavailability from fortified maize, and fortification per se will increase the intake of bioavailable iron and zinc. Corn masa flour or whole maize should be fortified with sodium iron ethylenediaminetetraacetate (NaFeEDTA), ferrous fumarate, or ferrous sulfate, and degermed corn flour should be fortified with ferrous sulfate or ferrous fumarate. The choice of zinc fortificant appears to have a limited impact on zinc bioavailability. Phytic acid is a major inhibitor of both iron and zinc absorption. Degermination at the mill will reduce phytic acid content, and degermed maize appears to be a suitable vehicle for iron and zinc fortification. Enzymatic phytate degradation may be a suitable home-based technique to enhance the bioavailability of iron and zinc from fortified maize. Bioavailability experiments with low phytic acid-containing maize varieties have suggested an improved zinc bioavailability compared to wild-type counterparts. The bioavailability of folic acid from maize porridge was reported to be slightly higher than from baked wheat bread. The bioavailability of vitamin A provided as encapsulated retinyl esters is generally high and is typically not strongly influenced by the food matrix, but has not been fully investigated in maize. PMID:24329552

  18. Preparation, characterization, and potential application of chitosan, chitosan derivatives, and chitosan metal nanoparticles in pharmaceutical drug delivery.

    Science.gov (United States)

    Ahmed, Tarek A; Aljaeid, Bader M

    2016-01-01

    Naturally occurring polymers, particularly of the polysaccharide type, have been used pharmaceutically for the delivery of a wide variety of therapeutic agents. Chitosan, the second abundant naturally occurring polysaccharide next to cellulose, is a biocompatible and biodegradable mucoadhesive polymer that has been extensively used in the preparation of micro-as well as nanoparticles. The prepared particles have been exploited as a potential carrier for different therapeutic agents such as peptides, proteins, vaccines, DNA, and drugs for parenteral and nonparenteral administration. Therapeutic agent-loaded chitosan micro- or nanoparticles were found to be more stable, permeable, and bioactive. In this review, we are highlighting the different methods of preparation and characterization of chitosan micro- and nanoparticles, while reviewing the pharmaceutical applications of these particles in drug delivery. Moreover, the roles of chitosan derivatives and chitosan metal nanoparticles in drug delivery have been illustrated. PMID:26869768

  19. Inbreeding drives maize centromere evolution.

    Science.gov (United States)

    Schneider, Kevin L; Xie, Zidian; Wolfgruber, Thomas K; Presting, Gernot G

    2016-02-23

    Functional centromeres, the chromosomal sites of spindle attachment during cell division, are marked epigenetically by the centromere-specific histone H3 variant cenH3 and typically contain long stretches of centromere-specific tandem DNA repeats (∼1.8 Mb in maize). In 23 inbreds of domesticated maize chosen to represent the genetic diversity of maize germplasm, partial or nearly complete loss of the tandem DNA repeat CentC precedes 57 independent cenH3 relocation events that result in neocentromere formation. Chromosomal regions with newly acquired cenH3 are colonized by the centromere-specific retrotransposon CR2 at a rate that would result in centromere-sized CR2 clusters in 20,000-95,000 y. Three lines of evidence indicate that CentC loss is linked to inbreeding, including (i) CEN10 of temperate lineages, presumed to have experienced a genetic bottleneck, contain less CentC than their tropical relatives; (ii) strong selection for centromere-linked genes in domesticated maize reduced diversity at seven of the ten maize centromeres to only one or two postdomestication haplotypes; and (iii) the centromere with the largest number of haplotypes in domesticated maize (CEN7) has the highest CentC levels in nearly all domesticated lines. Rare recombinations introduced one (CEN2) or more (CEN5) alternate CEN haplotypes while retaining a single haplotype at domestication loci linked to these centromeres. Taken together, this evidence strongly suggests that inbreeding, favored by postdomestication selection for centromere-linked genes affecting key domestication or agricultural traits, drives replacement of the tandem centromere repeats in maize and other crop plants. Similar forces may act during speciation in natural systems. PMID:26858403

  20. Cell Compound of Wound Surface After the Chitosan Membranes Application

    Directory of Open Access Journals (Sweden)

    Alexandr N. Oleshko

    2014-12-01

    Full Text Available Skin regeneration is a complex dynamic process by which restores the structure and function of the external cover. In the case of large defects of the skin allografts were the methods of choice in recent decades. The disadvantages of this therapy are the presence of pain, the appearance of scars and increased mortality. The tissue engineering methods artificial materials are widely developed in recent decades for large skin defects treatment. Chitosan is one of the most promising agents in the development of materials for the treatment of major defects of the skin. Currently, there are materials in the form of hydrogel, membranes and sponges based on chitosan, which has shown high efficacy in the treatment of wounds, both in experimental and clinical settings. Nevertheless, there is a need to find new forms and compositions based on chitosan to improve health outcomes, reduce product cost and optimizing the production of materials. The aim of this work was to study the features of skin regeneration after mechanical trauma when applying chitosan membranes at the different ages. The study of the processes of skin regeneration was carried out on 180 white laboratory rats of three age categories. All the animals were randomized into 2 series - experimental and control. After injury, the animals of control series were performed daily standard wound toilet with sterile gauze, experimental series - for the topical treatment received daily applications of experimental chitosan membranes. The animals were taken from the experiment in 1, 3, 7, 14 and 21 days, which corresponds to the terms that characterize the main stages of the process of skin regeneration. We used scraping by "surface biopsy" method as well as skin imprint to get a full picture of the cellular composition of the surface defect. The use of chitosan films in the management of mechanical trauma to the skin helps to optimize intercellular cooperation, reduce the severity of inflammatory

  1. Synthesis and characterization of chitosan alkyl urea.

    Science.gov (United States)

    Wang, Jing; Jiang, Ji-Zhou; Chen, Wei; Bai, Zheng-Wu

    2016-07-10

    Chitosan is a versatile material employed for various purposes in many fields including the development of chiral stationary phases for enantioseparation. Chitosan alkyl urea is a kind of intermediate used to prepare enantioseparation materials. In order to synthesize the intermediates, in the present work, a new way to prepare chitosan alkyl urea has been established: chitosan was first reacted with methyl chloroformate yielding N-methoxyformylated chitosan, which was then converted to chitosan alkyl urea through amine-ester exchange reaction. With a large excess of methyl chloroformate and primary amine of low stereohindrance, the amino group in chitosan could be almost completely converted to ureido group. The as-prepared chitosan alkyl urea derivatives were characterized by IR, (1)H NMR, (13)C NMR,(1)H-(1)H COSY and (1)H-(13)C HSQC NMR spectra. The chemical shifts of hydrogen and carbon atoms of glucose unit were assigned. It was found that the degree of substitution was obviously lower if cyclopropyl amine, aniline, tert-butyl amine and diethyl amine were used as reactants for the amine-ester exchange reaction. The reason was explained with the aid of theoretical calculations. PMID:27106154

  2. Degradation of chitosan for rice crops application

    International Nuclear Information System (INIS)

    A variety of techniques including chemical and enzymatic hydrolysis, and radiation degradation processes can be used to prepare low molecular weight chitosan. Degradation of chitosan by radiation can be carried out in solid state and liquid state. Radiation degraded polysaccharides has been reported to exhibit growth-stimulating activity like phytohormones that induce the promotion in germination, shoot and root elongation in variety of plants. In this study, the chitosan was irradiated in solid state (powder form) by gamma rays within the dose range of 25-75 kGy. And the irradiated chitosan was then irradiated in solution form in the presence of hydrogen peroxide. The effects of irradiation on the molecular weight and viscosity of the chitosan were investigated using Ubbelohde Capillary Viscometer. The molecular weight and viscosity of the chitosan decreased with increment of absorbed doses. In the presence of hydrogen peroxide, the molecular weight of chitosan could be further decreased. The effect of radiation degraded chitosan on the growth promotion of rice was investigated and it was shown during seedling period of 15 days for transplanting whereby the growth is 15%-20% faster than using chemicals growth promoters. (authors)

  3. Application of irradiated chitosan for fruit preservation

    International Nuclear Information System (INIS)

    Application of irradiated chitosan has been investigated for coating of fruit preservation. Anti-fungal activity of chitosan was induced by γ-ray irradiation in dry condition at 25 kGy. The irradiated chitosan can suppress the growth of Aspergillus. spp. and Fusarium. spp. isolated from Vietnam mango. Fusarium. spp. was sensitive for irradiated chitosan than the other strains. The coating from irradiated chitosan solution at dose 31 kGy has prolonged the storage life of mango from 7 to 15 days. At the 15th day mango keeps good colour, natural ripening, without spoilage, weight loss 10%, whereas the control is spoiled completely and the sample of fruit with unirradiated chitosan coating could not ripe. The effect is due to the anti-fungal activity and change in physico-chemical properties of chitosan by irradiation. Radiation causes the decrease in viscosity affecting the gas permeability of coating film. The irradiated chitosan coating has positive effect on mango that is susceptible to chilling injury at low storage temperature. (author)

  4. Macroporous chitosan hydrogels: Effects of sulfur on the loading and release behaviour of amino acid-based compounds.

    Science.gov (United States)

    Elviri, Lisa; Asadzadeh, Maliheh; Cucinelli, Roberta; Bianchera, Annalisa; Bettini, Ruggero

    2015-11-01

    Chitosan is a biodegradable, biocompatible polymer of natural origin widely applied to the preparation of functional hydrogels suitable for controlled release of drugs, peptides and proteins. Non-covalent interactions, expecially ionic interactions, are the main driver of the loading and release behaviour of amino acids or peptides from chitosan hydrogels. With the aim to improve the understanding of the mechanisms governing the behaviour of chitosan hydrogels on peptide uptake and delivery, in this paper the attention was focused on the role played by sulfur on the interactions of chitosan hydrogels with sulfur-containing amino acids (AA) and peptides. Hence, loading and release experiments on cysteine, cystine and glutathione (SH containing amino acid, dipeptide and tripeptide, respectively) as well as on glycine and valine as apolar amino acids were carried out. For these puroses, chitosan hydrogels were prepared in an easy and reproducible manner by a freeze-gelation process on a poly-L-lysine coated support. The hydrogel surface pore size, uniformity and distribution were tested. Optimal results (D50 = 26 ± 4 μm) were obtained by using the poly-L-lysine positively-charged surface. The loading results gathered evidenced that the sulfur-containing molecules presented an increased absorption both in terms of rate and extent by chitosan hydrogels with respect to nonpolar amino acids, mainly due to ionic and hydrogen bond interactions. ATR-FTIR analysis carried out on chitosan hydrogels, with and without the AA related compounds to study putative interactions, supported these apparent sulfur-dependent results. Finally, chitosan hydrogels displayed excellent retention capabilities (AA release <5%) for all AA, strongly supporting the use of chitosan hydrogels as matrix for controlled drug release. PMID:26256323

  5. MaizeGDB's New Genome Browser Project

    Science.gov (United States)

    MaizeGDB (http://www.maizegdb.org) is the community database for maize genetics and genomics. Based upon the 2006 MaizeGDB Working Group Report (available at http://www.maizegdb.org/working_group.php) and the Allerton Report (http://www.maizegdb.org/AllertonReport.doc), it has become evident that th...

  6. Zearalenone contamination in farm maize silage

    OpenAIRE

    L. Cavallarin; S. Antoniazzi; E. Tabacco; G. Borreani

    2010-01-01

    Whole-plant maize silage, stored in horizontal silos, is the main diet source of lactating dairy cows in Italy. Mycotoxin contamination of maize grain has widely been described (Hussein and Brasel, 2001), while limited information is available on mycotoxins in maize silage (Oldenburg, 1991).

  7. The Role of Nitrogen and Sulfur Interaction in Maize Quality(Zea mays L. )

    Institute of Scientific and Technical Information of China (English)

    XIE Rui-zhi; DONG Shu-ting; HU Chang-hao; WANG Kong-jun

    2003-01-01

    Two hybrids of maize with different responses to sulfur were used in the pool experiment. Theeffects of nitrogen and sulfur on the grain quality of maize were evaluated. The results indicated that grainquality changed with the nutrition supply. The contents of proteins, amino acids, soluble sugar, crude fat,But the effects of nitrogen and sulfur were not the same. Nitrogen increased starch content of the grain, but Sdecreased the content. Both N and S enhanced the proportion of amylopectin in starch. Sulfur nutrition signif-icantly improved the grain quality of maize when a large amount of nitrogen was used together. Both hybridshad similar response to N and S treatments.

  8. Preparation and Blood Compatibility of Oxidized-chitosan Films

    Institute of Scientific and Technical Information of China (English)

    Yue Dong YANG; Jiu Gao YU; Yong Guo ZHOU; Pei Guo LI

    2005-01-01

    Chitosan membrane was modified by the selective oxidization of chitosan molecules on its surface with NO2 gas. FTIR spectra indicated there were plenty of-COOH and -COO- groups on the modified membrane surface. The SEM study showed the modified membrane surface was rough rather than smooth as chitosan membrane. All antithrombosis test, hemolysis test and blood cell morphology observation with SEM revealed that modified chitosan membranes have superior blood compatibility to chitosan.

  9. Application Of Chitosan/Cyclodextrin Nanoparticles for Tissue Glutathione Delivery

    OpenAIRE

    Rotar O.V.; Rotar V.I.

    2013-01-01

    The aim of this study was to investigate an ability of chitosan nanoparticles for tissue delivery of the peptide glutathione. Formulations composed of chitosan or chitosan plus cyclodextrin-beta comlex were prepared. Reduced glutathione was loaded and delivered to mucosal layer of small intestine after ischemia-reperfusion injury more efficiently in chitosan/cyclodextrin-beta nanoparticles. From the data obtained, we believe that chitosan/cyclodextrin nanoparticles can be used for the oral adm...

  10. Chitosan Fibers Modified with HAp/β–TCP Nanoparticles

    OpenAIRE

    Dariusz Wawro; Luciano Pighinelli

    2011-01-01

    This paper describes a method for preparing chitosan fibers modified with hydroxyapatite (HAp), tricalcium phosphate (β-TCP), and HAp/β-TCP nanoparticles. Fiber-grade chitosan derived from the northern shrimp (Pandalus borealis) and nanoparticles of tricalcium phosphate (β-TCP) and hydroxyapatite (HAp) suspended in a diluted chitosan solution were used in the investigation. Diluted chitosan solution containing nanoparticles of Hap/β-TCP was introduced to a 5.16 wt% solution of chitosan in 3.0...

  11. PHARAMACEUTICAL RELEVANCE OF CROSSLINKED CHITOSAN IN MICROPARTICULATE DRUG DELIVERY

    OpenAIRE

    Pahuja Sonia; Aggarwal Shweta

    2013-01-01

    This review highlights the importance of cross-linking with chitosan. Derivatisation of chitosan leads to the cross-linking of chitosan without changing its fundamental skelton structure. Cross-linking agents are broadly divided into two categories i.e Physical and chemical cross-linking; on the basis of interaction with chitosan. The various cross-linking agents used for the preparation of chitosan microspheres and its mechanism of cross-linking have also been described. This article also re...

  12. Preparation and characterization of magnetic chitosan particles for hyperthermia application

    International Nuclear Information System (INIS)

    The size and shape of magnetic chitosan particles were found to be dependent on both the barium ferrite/chitosan (BF/C) ratio and viscosity of a chitosan solution. The saturation magnetization of magnetic chitosan particles varied directly with the BF/C ratio, while coercivity remained almost constant. Notably, incorporated chitosan was shown to exert substantial activity with regard to low cytotoxicity and high heating rate

  13. Faster chitosan production by mucoralean strains in submerged culture

    OpenAIRE

    Amorim Rosa Valéria da Silva; Souza Wanderley de; Fukushima Kazutaka; Campos-Takaki Galba Maria de

    2001-01-01

    Production of chitosan was conducted using two Mucoralean strains, Mucor racemosus and Cunninghamella elegans. Chitosan was extracted from mycelia of M. racemosus and C. elegans at different growth phases on YPD medium. In both fungi, chitosan was rapidly produced, while highest yield of extractable chitosan was found in 24h of cultivation in submerged culture. The yield of chitosan isolated from dry mycelia of M. racemosus was about 40% higher than from C. elegans. The degree of N-acetylatio...

  14. Preparation of Chitosan-g-HEMA by radiation technique

    International Nuclear Information System (INIS)

    Chitosan-g-HEMA copolymer was prepared by radiation technique. Effects of chitosan and HEMA concentrations, irradiation dose on grafting have been investigated. Results showed that grafting process of HEMA onto chitosan occurred smoothly and achieved high grafting degree, up to 600% at 5 kGy, with 15% HEMA and 1.5% chitosan. The obtained copolymer was characterized by IR spectra, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). These measured parameters proved that HEMA grafted onto chitosan backbone. (author)

  15. Real-time monitoring of peptide grafting onto chitosan films using capillary electrophoresis.

    Science.gov (United States)

    Taylor, Danielle L; Thevarajah, Joel J; Narayan, Diksha K; Murphy, Patricia; Mangala, Melissa M; Lim, Seakcheng; Wuhrer, Richard; Lefay, Catherine; O'Connor, Michael D; Gaborieau, Marianne; Castignolles, Patrice

    2015-03-01

    Chitosan, being antimicrobial and biocompatible, is attractive as a cell growth substrate. To improve cell attachment, arginine-glycine-aspartic acid-serine (RGDS) peptides were covalently grafted to chitosan films, through the widely used coupling agents 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC-HCl) and N-hydroxysuccinimide (NHS), via the carboxylic acid function of the RGDS molecule. The grafting reaction was monitored, for the first time, in real time using free-solution capillary electrophoresis (CE). This enabled fast separation and determination of the peptide and all other reactants in one separation with no sample preparation. Covalent RGDS peptide grafting onto the chitosan film surface was demonstrated using solid-state NMR of swollen films. CE indicated that oligomers of RGDS, not simply RGDS, were grafted on the film, with a likely hyperbranched structure. To assess the functional properties of the grafted films, cell growth was compared on control and peptide-grafted chitosan films. Light microscopy and polymerase chain reaction (PCR) analysis demonstrated greatly improved cell attachment to RGDS-grafted chitosan films. PMID:25680633

  16. Preparation and Adsorption Ability of Polysulfone Microcapsules Containing Modified Chitosan Gel

    Institute of Scientific and Technical Information of China (English)

    CHEN Fei; LUO Guangsheng; YANG Weiwei; WANG Yujun

    2005-01-01

    Chemically modified chitosan beads containing polyethyleneimine (PEI) were prepared to improve the metal ion adsorption capacity of the chitosan beads and their mechanical stability and to limit their biodegradability. The modified beads were encapsulated with the polymer material polysulfone by a novel surface coating method named the emulsion phase inversion method. The adsorption properties of the modified beads and the microstructures of the polysulfone coating layer were then analyzed. The experimental results showed that the PEI was successfully linked onto the chitosan beads. The density of the -NH2 groups in the modified beads was significantly increased, while the water content was reduced. The coating layer thickness was about 200 (m. The modified chitosan gel beads had excellent Cu(II) adsorption capacity, with a maximum Cu(II) adsorption capacity 1.34 times higher than that of the unmodified beads. The results show that even with the polysulfone coating the adsorption kinetics of the modified beads is still better than those of the unmodified beads. The modifications improve the mass transfer performance of the chitosan beads as well as the bead stability.

  17. Mechanical and biological properties of chitosan/carbon nanotube nanocomposite films.

    Science.gov (United States)

    Aryaei, Ashkan; Jayatissa, Ahalapitiya H; Jayasuriya, Ambalangodage C

    2014-08-01

    In this article, different concentrations of multiwalled carbon nanotube (MWCNT) were homogeneously dispersed throughout the chitosan (CS) matrix. A simple solvent-cast method was used to fabricate chitosan films with 0.1, 0.5, and 1% of MWCNT with the average diameter around 30 nm. The CS/MWCNT films were characterized for structural, viscous and mechanical properties with optical microscopy, wide-angle X-ray diffraction, Raman spectroscopy, tensile test machine, and microindentation testing machine. Murine osteoblasts were used to examine the cell viability and attachment of the nanocomposite films at two time points. In comparison to the pure chitosan film, the mechanical properties, including the tensile modulus and strength of the films, were greatly improved by increasing the percentage of MWCNT. Furthermore, adding MWCNT up to 1% increased the viscosity of the chitosan solution by 15%. However, adding MWCNT decreased the samples ductility and transparency. In biological point of view, no toxic effect on osteoblasts was observed in the presence of different percentages of MWCNT at day 3 and day 7. This investigation suggested MWCNT could be a promising candidate for improving chitosan mechanical properties without inducing remarkable cytotoxicity on bone cells. PMID:24108584

  18. Chitosan dan Aplikasi Klinisnya Sebagai Biomaterial

    Directory of Open Access Journals (Sweden)

    Bambang Irawan

    2015-10-01

    Full Text Available The development of new materials with both organic and inorganic structures is of great interest to obtain special material properties. Chitosan [2-amino-2-deoxy-D-glucan] can be obtained by N-deacetylation of chitin. Chitin is the second most abundant biopolymer in nature and the supporting material of crustaceans, insects, fungi etc. Chitosan is unique polysaccharide and has been widely used in various biomedical application due to its biocompatibility, low toxicity, biodegradability, non-immunogenic and non-carcinogenic character. In the past few years, chitosan and some of its modifications have been reported for use in biomedical applications such as artificial skin, wound dressing, anticoagulant, suture, drug delivery, vaccine carrier and dietary fibers. Recently, the use of chitosan and its derivatives has received much attention as temporary scaffolding to promotie mineralization or stimulate endochodral ossification. This article aims to give a broad overview of chitosan and its clinical applications as biomaterial.

  19. Hydrogels made from chitosan and silver nitrate.

    Science.gov (United States)

    Kozicki, Marek; Kołodziejczyk, Marek; Szynkowska, Małgorzata; Pawlaczyk, Aleksandra; Leśniewska, Ewa; Matusiak, Aleksandra; Adamus, Agnieszka; Karolczak, Aleksandra

    2016-04-20

    This work describes a gelation of chitosan solution with silver nitrate. Above the critical concentration of chitosan (c*), continuous hydrogels of chitosan-silver can be formed. At lower concentrations, the formation of nano- and micro-hydrogels is discussed. The sol-gel analysis was performed to characterise the hydrogels' swelling properties. Moreover, the following were employed: (i) mechanical testing of hydrogels, (ii) inductively coupled plasma-optical emission spectroscopy (ICP-OES) for the measurement of silver concentration, (iii) scanning electron microscopy (SEM) to examine the morphology of products obtained, and (iv) dynamic light scattering (DLS) and UV-vis spectrophotometry to examine products formed at low concentration of chitosan (cchitosan used that showed no such activity. PMID:26876830

  20. Potassium leakage and maize seed physiological potential

    Directory of Open Access Journals (Sweden)

    Miguel Mariane Victorio de Carvalho

    2002-01-01

    Full Text Available Seed production usually requires fast decisions to improve the efficacy of seed handling during harvesting, processing and storage. Seed technologists have focused on the development or improvement of procedures which allow rapid and consistent identification of higher quality seed lots. This research verified the effectiveness of the potassium leachate test on the evaluation of the physiological potential of maize seeds in comparison to recommended seed vigor tests. Five seed lots of the hybrid Avant were submitted to the potassium leachate, standard germination, first count, accelerated aging, electrical conductivity, field emergence and cold tests. The amount of potassium leachate was determined after seed imbibition for 30, 60, 90, 120, 150 and 180 minutes, at 25°C; a flame photometer adjusted to 50 mug K+ mL-1 pattern and reading 50 was used to determine the amount of leached potassium. The potassium leachate test consistently ranked the seed lots according to their physiological quality in comparison to other tests, and is a new alternative test for maize seed quality control programs.

  1. Partial Budget Technique on Different Maize Intercropping Technologies Practised by the Farmers

    OpenAIRE

    S.M.A. Shiblee; A. F. M. F. Rahman; M. Kamruzzaman P.C. Sarker; A. Muqit; M. A. A. Begum

    2000-01-01

    There were as many as eleven different maize intercropping technologies detected in the study area namely, Maize + Chilli, Maize + Chilli + Yard long bean, Maize + Chilli + Potato, Maize + Chilli, Maize + Chilli + Potato + Cucumber, Mize + Cow pea, Maize + Cucumber, Maize + Yar long bean + Cucumber, Maize + Sweet groud and Maize + Sweet groud + Tomato. It was found in the study that the highest MRR was received by the intercropping Maize + Chilli + Potato + Cucumber which was 598% and highest...

  2. Antimicrobial and antitumor activities of chitosan from shiitake stipes, compared to commercial chitosan from crab shells.

    Science.gov (United States)

    Chien, Rao-Chi; Yen, Ming-Tsung; Mau, Jeng-Leun

    2016-03-15

    Chitosan was prepared by alkaline N-deacetylation of chitin obtained from shiitake stipes and crab shells and its antimicrobial and antitumor activities were studied. Chitosan from shiitake stipes and crab shells exhibited excellent antimicrobial activities against eight species of Gram positive and negative pathogenic bacteria with inhibition zones of 11.4-26.8mm at 0.5mg/ml. Among chitosan samples, shiitake chitosan C120 was the most effective with inhibition zones of 16.4-26.8mm at 0.5mg/ml. In addition, shiitake and crab chitosan showed a moderate anti-proliferative effect on IMR 32 and Hep G2 cells. At 5mg/ml, the viability of IMR 32 cells incubated with chitosan was 68.8-85.0% whereas that of Hep G2 cells with chitosan was 60.4-82.9%. Overall, shiitake chitosan showed slightly better antimicrobial and antitumor activities than crab chitosan. Based on the results obtained, shiitake and crab chitosan were strong antimicrobial agents and moderate antitumor agents. PMID:26794761

  3. Comparative study on the effects of negatively-charged biopolymers on chitosan-based gels for the development of instantaneous gels

    International Nuclear Information System (INIS)

    Polymeric electrolytic complexes are solutions of charged/ionized chains. These solutions of positive and negative charge can be combined to make instantaneous networks bonded by electrostatic interactions, a gel network. These electrostatic interaction allows for easy application in injectable gels as the network can be temporarily distributed with the application of force and reformed on the relief of it. Possible applications for these injectable gels include drug delivery and wound-healing. κ-Carrageenan, dextran sulfate, alginate, and chitosan are polyelectrolytic biocompatible polymers which are widely studied and used for a variety of biomedical applications. Gel networks are made by combining a negatively-charged (κ-Carrageenan, dextran sulfate, or alginate) and positively charged (chitosan) solutions. The strong electrostatic interaction between the opposite charges from the gel network and the inherent biocompatibility of the polymers allow future biomedical applications. Quat 188-modified chitosan has additional sites for electrostatic bonding, can be dissolved in neutral, basic, and acidic pH, and has shown inherent antibacterial activity. The objectives of this study are the following: to formulate chitosan-based gels mixing solutions of chitosan with solutions of either κ-Carrageenan, dextran sulfate, or alginate, study the gelation of the gels as function of time and pH (4, 7, and 9) using UV-Vis, characterize the chitosan-based gels through DSC and DMA, characterize the physiological degradation of the chitosan-based gels, and compare results with those from Quat 188-modified chitosan-based gels. Polyelectrolytic solutions of chitosan and negatively-charged biopolymer of similar viscosities were mixed. It was determined from the UV-Vis spectroscopy of the chitosan-carrageenan gels under pH7 buffer that the increase of concentration by a factor of 5 for 0.006M-0.0095M and 1.25 for 0.0095M-0.0150M Chitosan-Carrageenan gels improved gelation by the

  4. New inoculants on maize silage fermentation

    Directory of Open Access Journals (Sweden)

    Fábia Giovana do Val de Assis

    2014-08-01

    Full Text Available The objective of this study was to evaluate the effect of bacterial inoculants at two inoculation rates on chemical and biological characteristics of maize silage. The treatments consisted of two inoculating rates (5 and 6 log cfu g-1 of forage for each strain of lactic acid bacteria (LAB identified as Lactobacillus buchneri, L. hilgardii, or L. plantarum. The maize was ensiled in experimental PVC silos. Samples were taken for the determination of the contents of dry matter (DM, crude protein (CP, neutral detergent fiber (NDF, water-soluble carbohydrates (WSC, organic acids and alcohols, for the evaluation of the populations of lactic acid bacteria, yeasts, filamentous fungi, and for the determination of pH values during ensilage and after 30 or 90 days of fermentation. The doses of inoculants did not promote significant differences on the evaluated characteristics. There was effect of inoculants on acetic acid, 1.2-propanediol, LAB population, filamentous fungi, and pH value. No significant influence of the treatments with inoculants was observed in the variables DM, WSC, CP, lactic acid concentrations, or ethanol. The maximum temperature, i.e., the time to achieve the maximum temperature (TMT and aerobic stability (AS, was not influencied by treatments. However, a decrease in maximum temperature, an increase in TMT, and improvement in the AS were observed after 90 days of fermentation. These results proved the advantage of microbial inoculation. The treatments influenced LAB populations and filamentous fungi, but no effect was observed on the yeast population. The best inoculation dose is 6 cfu g-1 of forage because it provides higher reduction of filamentous fungi in maize silage, thereby decreasing the aerobic deterioration by these microorganisms.

  5. Design and application of chitosan microspheres as oral and nasal vaccine carriers: an updated review

    Directory of Open Access Journals (Sweden)

    Islam MA

    2012-12-01

    Full Text Available Mohammad Ariful Islam,1–3,* Jannatul Firdous,1–3,* Yun-Jaie Choi,1 Cheol-Heui Yun,1–4 Chong-Su Cho1,21Department of Agricultural Biotechnology, 2Research Institute for Agriculture and Life Sciences, 3Center for Food and Bioconvergence, 4World Class University Biomodulation Program, Seoul National University, Seoul, South Korea*These authors contributed equally to this workAbstract: Chitosan, a natural biodegradable polymer, is of great interest in biomedical research due to its excellent properties including bioavailability, nontoxicity, high charge density, and mucoadhesivity, which creates immense potential for various pharmaceutical applications. It has gelling properties when it interacts with counterions such as sulfates or polyphosphates and when it crosslinks with glutaraldehyde. This characteristic facilitates its usefulness in the coating or entrapment of biochemicals, drugs, antigenic molecules as a vaccine candidate, and microorganisms. Therefore, chitosan together with the advance of nanotechnology can be effectively applied as a carrier system for vaccine delivery. In fact, chitosan microspheres have been studied as a promising carrier system for mucosal vaccination, especially via the oral and nasal route to induce enhanced immune responses. Moreover, the thiolated form of chitosan is of considerable interest due to its improved mucoadhesivity, permeability, stability, and controlled/extended release profile. This review describes the various methods used to design and synthesize chitosan microspheres and recent updates on their potential applications for oral and nasal delivery of vaccines. The potential use of thiolated chitosan microspheres as next-generation mucosal vaccine carriers is also discussed.Keywords: chitosan microspheres, oral, nasal, vaccine delivery, mucosal and systemic immune responses

  6. Effects of Chitosan Concentration on the Protein Release Behaviour of Electrospun Poly(ε-caprolactone)/Chitosan Nanofibers

    OpenAIRE

    Fatemeh Roozbahani; Naznin Sultana; Davood Almasi; Farnaz Naghizadeh

    2015-01-01

    Poly(ε-caprolactone)/chitosan (PCL/chitosan) blend nanofibers with different ratios of chitosan were electrospun from a formic acid/acetic acid (FA/AA) solvent system. Bovine serum albumin (BSA) was used as a model protein to incorporate biochemical cues into the nanofibrous scaffolds. The morphological characteristics of PCL/chitosan and PCL/chitosan/BSA Nanofibers were investigated by scanning electron microscopy (SEM). Fourier transform infrared spectroscopy (FTIR) was used to detect the p...

  7. Thermal behavior and properties of chitosan fibers enhanced polysaccharide hydrogels

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Chitosan, in fiber form, was introduced into polysaccharide hydrogels. • Strong interactions in hybrid hydrogels are systematically investigated. • Dehydration activation energy decreases as the content of CSFs increases. • Chitosan fibers improved hydrogels’ structural stability and storage modulus. - Abstract: Composite hydrogel based on chitosan fibers (CSFs), high- and low-acyl gellan gum (HLG) was fabricated. The strong interactions between CSFs and HLG were confirmed by Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD) and thermogravimetric (TG) analysis. Differential scanning calorimetry (DSC) study shows that the dehydration activation energy decreases as the content of CSFs increases. The rheological measurement showed that the storage modulus of 2.0CSF–HLG (where 2.0 represents the mass ratio between CSF and HLG) hydrogels is 48 kPa at regular frequency of 1 rad/s, which is 1.8 times higher than that of HLG hydrogel. In addition, the SEM images demonstrated that 2.0CSF–HLG hydrogel exhibits three dimensional architectures with HLG attaching to CSFs. A weak swelling capacity of CSF–HLG hydrogels was observed, indicating fibroid CSFs would hinder the movement of HLG chain segments in solution

  8. One-step electrospinning of cross-linked chitosan fibers.

    Science.gov (United States)

    Schiffman, Jessica D; Schauer, Caroline L

    2007-09-01

    Chitin is a nitrogen-rich polysaccharide that is abundant in crustaceans, mollusks, insects, and fungi and is the second most abundant organic material found in nature next to cellulose. Chitosan, the N-deacetylated derivative of chitin, is environmentally friendly, nontoxic, biodegradable, and antibacterial. Fibrous mats are typically used in industries for filter media, catalysis, and sensors. Decreasing fiber diameters within these mats causes many beneficial effects such as increased specific surface area to volume ratios. When the intrinsically beneficial effects of chitosan are combined with the enhanced properties of nanofibrous mats, applications arise in a wide range of fields, including medical, packaging, agricultural, and automotive. This is particularly important as innovative technologies that focus around bio-based materials are currently of high urgency, as they can decrease dependencies on fossil fuels. We have demonstrated that Schiff base cross-linked chitosan fibrous mats can be produced utilizing a one-step electrospinning process that is 25 times faster and, therefore, more economical than a previously reported two-step vapor-cross-linking method. These fibrous mats are insoluble in acidic, basic, and aqueous solutions for 72 h. Additionally, this improved production method results in a decreased average fiber diameter, which measures 128 +/- 40 nm. Chemical and structural analyses were conducted utilizing Fourier transform infrared spectroscopy, solubility studies, and scanning electron microscopy. PMID:17696400

  9. Thermal behavior and properties of chitosan fibers enhanced polysaccharide hydrogels

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Limei, E-mail: 20134014002@stu.suda.edu.cn [Institute of Functional Nano and Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou, Jiangsu 215123 (China); Wang, Binghao, E-mail: 20104209162@suda.edu.cn [Institute of Functional Nano and Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou, Jiangsu 215123 (China); Bai, Tong-chun, E-mail: tcbai@suda.edu.cn [School of Chemistry, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu 215123 (China); Dong, Bin, E-mail: bdong@suda.edu.cn [Institute of Functional Nano and Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou, Jiangsu 215123 (China)

    2014-05-01

    Graphical abstract: - Highlights: • Chitosan, in fiber form, was introduced into polysaccharide hydrogels. • Strong interactions in hybrid hydrogels are systematically investigated. • Dehydration activation energy decreases as the content of CSFs increases. • Chitosan fibers improved hydrogels’ structural stability and storage modulus. - Abstract: Composite hydrogel based on chitosan fibers (CSFs), high- and low-acyl gellan gum (HLG) was fabricated. The strong interactions between CSFs and HLG were confirmed by Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD) and thermogravimetric (TG) analysis. Differential scanning calorimetry (DSC) study shows that the dehydration activation energy decreases as the content of CSFs increases. The rheological measurement showed that the storage modulus of 2.0CSF–HLG (where 2.0 represents the mass ratio between CSF and HLG) hydrogels is 48 kPa at regular frequency of 1 rad/s, which is 1.8 times higher than that of HLG hydrogel. In addition, the SEM images demonstrated that 2.0CSF–HLG hydrogel exhibits three dimensional architectures with HLG attaching to CSFs. A weak swelling capacity of CSF–HLG hydrogels was observed, indicating fibroid CSFs would hinder the movement of HLG chain segments in solution.

  10. Alginate Hydrogels Coated with Chitosan for Wound Dressing

    Directory of Open Access Journals (Sweden)

    Maria Cristina Straccia

    2015-05-01

    Full Text Available In this work, a coating of chitosan onto alginate hydrogels was realized using the water-soluble hydrochloride form of chitosan (CH-Cl, with the dual purpose of imparting antibacterial activity and delaying the release of hydrophilic molecules from the alginate matrix. Alginate hydrogels with different calcium contents were prepared by the internal setting method and coated by immersion in a CH-Cl solution. Structural analysis by cryo-scanning electron microscopy was carried out to highlight morphological alterations due to the coating layer. Tests in vitro with human mesenchymal stromal cells (MSC were assessed to check the absence of toxicity of CH-Cl. Swelling, stability in physiological solution and release characteristics using rhodamine B as the hydrophilic model drug were compared to those of relative uncoated hydrogels. Finally, antibacterial activity against Escherichia coli was tested. Results show that alginate hydrogels coated with chitosan hydrochloride described here can be proposed as a novel medicated dressing by associating intrinsic antimicrobial activity with improved sustained release characteristics.

  11. Functional modification of chitosan for biomedical application

    Science.gov (United States)

    Tang, Ruogu

    Chitosan is a linear polysaccharide. Normally commercial chitosan consists of randomly distributed beta-(1-4)-linked D-glucosamine (deacetylated proportion) and N-acetyl-D-glucosamine (acetylated proportion) together. Chitosan has been proved to be a multifunctional biopolymer that presents several unique properties due to free amino groups in the repeating unit therefore chitosan has been widely applied in various areas. To be specific, provided by the excellent biocompatibility, chitosan is expected to be used in biological and medical applications including wound dressing, implants, drug carrier/delivery, etc. In this thesis, we worked on chitosan functionalization for biomedical application. The thesis are composed of three parts: In the first part, we focused on modifying the chitosan thin film, chemically introducing the nitric oxide functional groups on chitosan film. We covalently bonded small molecule diazeniumdiolates onto the chitosan films and examined the antimicrobial function and biocompatibility. Commercial chitosan was cast into films from acidic aqueous solutions. Glutaraldehyde reacted with the chitosan film to introduce aldehyde groups onto the chitosan film (GA-CS film). GA-CS reacted with a small molecule NO donor, NOC-18, to covalently immobilize NONO groups onto the polymer (NO-CS film). The-CHO and [NONO] group were verified by FT IR, UV and Griess reagent. The NO releasing rate in aqueous solution and and thermal stability were studied quantitatively to prove its effectiveness. A series of antimicrobial tests indicated that NO-CS films have multiple functions: 1. It could inhibit the bacteria growth in nutrient rich environment; 2. It could directly inactivate bacteria and biofilm; 3. It could reduce the bacteria adherence on the film surface as well as inhibit biofilm formation. In addition, the NO-CS film was proved to be biocompatible with cell and it was also compatible with other antibiotics like Amoxicillin. In the second part, we

  12. 3D composites based on the blends of chitosan and collagen with the addition of hyaluronic acid.

    Science.gov (United States)

    Sionkowska, Alina; Kaczmarek, Beata; Lewandowska, Katarzyna; Grabska, Sylwia; Pokrywczyńska, Marta; Kloskowski, Tomasz; Drewa, Tomasz

    2016-08-01

    3D porous composites based on blends of chitosan, collagen and hyaluronic acid were obtained through the lyophilization process. Mechanical properties, swelling behavior and thermal stability of the blends were studied. Moreover, SEM images were taken and the structure of the blends was studied. Biological properties of the materials obtained were investigated by analyzing of proliferation rate of fibroblast cells incubated with biomaterial extract using MTT assay (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide). The results showed that the properties of 3D composites based on the blends of chitosan and collagen were altered after the addition 1%, 2% and 5% of hyaluronic acid. Mechanical properties and thermal stability of chitosan/collagen blends were improved in the presence of hyaluronic acid in the composite. New 3D materials based on the blends of chitosan, collagen and hyaluronic acid were non-toxic and did not significantly affect cell morphology. PMID:27151670

  13. Glycemic responses to maize flour stiff porridges prepared using local recipes in Malawi.

    Science.gov (United States)

    Mlotha, Vincent; Mwangwela, Agnes Mbachi; Kasapila, William; Siyame, Edwin W P; Masamba, Kingsley

    2016-03-01

    Glycemic index is defined as the incremental area under the blood glucose response curve of a 50 g carbohydrate portion of a test food expressed as a percent of the response to the same amount of carbohydrate from a standard food taken by the same subject. This study investigated glycemic index of maize stiff porridges consumed as staple food in Malawi and a large majority of other countries in sub-Saharan Africa to identify areas for improvement in consumer diets. Stiff porridges were prepared using flour from whole maize, maize grits, and fermented maize grits. The porridges were served to 11 healthy volunteers for 3 weeks, with two serving sessions a week. Glucose was served as a reference food during weekly serving sessions. Results from descriptive analysis revealed that glycemic responses varied across subjects and porridge types. Porridge prepared from fermented maize grits had moderate glycemic index of 65.49 and was comparable in nutrient composition and sensory characteristics with the other test porridges. Glycemic indices of the porridges prepared from whole maize flour and grits were high at 94.06 and 109.64, respectively, attributed to the effect of traditional maize flour processing, preparation, and cooking methods used. The study also calculated glyaemic load of the porridges and drew recommendations to inform diet planning and modifications for healthy and diabetic individuals. PMID:27004122

  14. Proline, glycine betaine, total phenolics and pigment contents in response to osmotic stress in maize seedlings

    Directory of Open Access Journals (Sweden)

    SAJJAD MOHARRAMNEJAD

    2015-12-01

    Full Text Available In order to evaluate the fresh weight, RWC, pigment content, total phenolics, proline and glycine betaine responses of maize inbred lines to osmotic stress, a factorial experiment was carried out under laboratory conditions with two maize inbred lines (B73 and MO17 and two osmotic stress levels induced by PEG (control and -0.6 MPa. Fresh weight significantly decreased under drought stress. On the basis of percent inhibition in fresh weight at the osmotic stress MO17 was ranked as tolerant (inhibition 45.30%, and B73 drought sensitive (inhibition more than 50%. Leaf relative water content (RWC was significantly decreased in both inbred lines under osmotic stress. The pigment concentrations were substantially declined in both maize inbreds under osmotic stressed conditions. However, this reduction was less in B73 than MO17. Osmoitc stress declined the levels of total phenolics in both maize inbreds. On the other hand, the osmotic stress markedly enhanced the levels of proline and glycine betaine in both maize inbreds, but this was more pronounced in MO17. The present results showed that osmotic stress retards the growth and some biochemical attributes of maize inbreds. In conclusion, the level of proline and glycine betaine in maize could improve drought tolerance.

  15. MaizeGDB update: new tools, data and interface for the maize model organism database.

    Science.gov (United States)

    Andorf, Carson M; Cannon, Ethalinda K; Portwood, John L; Gardiner, Jack M; Harper, Lisa C; Schaeffer, Mary L; Braun, Bremen L; Campbell, Darwin A; Vinnakota, Abhinav G; Sribalusu, Venktanaga V; Huerta, Miranda; Cho, Kyoung Tak; Wimalanathan, Kokulapalan; Richter, Jacqueline D; Mauch, Emily D; Rao, Bhavani S; Birkett, Scott M; Sen, Taner Z; Lawrence-Dill, Carolyn J

    2016-01-01

    MaizeGDB is a highly curated, community-oriented database and informatics service to researchers focused on the crop plant and model organism Zea mays ssp. mays. Although some form of the maize community database has existed over the last 25 years, there have only been two major releases. In 1991, the original maize genetics database MaizeDB was created. In 2003, the combined contents of MaizeDB and the sequence data from ZmDB were made accessible as a single resource named MaizeGDB. Over the next decade, MaizeGDB became more sequence driven while still maintaining traditional maize genetics datasets. This enabled the project to meet the continued growing and evolving needs of the maize research community, yet the interface and underlying infrastructure remained unchanged. In 2015, the MaizeGDB team completed a multi-year effort to update the MaizeGDB resource by reorganizing existing data, upgrading hardware and infrastructure, creating new tools, incorporating new data types (including diversity data, expression data, gene models, and metabolic pathways), and developing and deploying a modern interface. In addition to coordinating a data resource, the MaizeGDB team coordinates activities and provides technical support to the maize research community. MaizeGDB is accessible online at http://www.maizegdb.org. PMID:26432828

  16. Staple Crops, Smallholder Farmers and Multinationals: The ‘Water-Efficient Maize for Africa’ Project

    OpenAIRE

    Lumpkin, Thomas A.; Armstrong, Janice

    2009-01-01

    Doubling food production by 2050 under conditions of climate change and depleted natural resources requires increased investment and creative approaches. The Water-Efficient Maize for Africa (WEMA) project, a five-year public–private partnership begun in 2008 and led by the African Agricultural Technology Foundation (AATF), is an excellent example. Under WEMA, Monsanto, the International Maize and Wheat Improvement Center (CIMMYT), and national agricultural research systems in Kenya, Mozambiq...

  17. Increased maize yield using slow-release attapulgite-coated fertilizers

    OpenAIRE

    Guan, Yu; Song, Chao; Gan, Yantai; Li, Feng-Min

    2014-01-01

    International audience Slow-release fertilizers could improve the productivity of field crops and reduce environmental pollution. So far, no slow-release fertilizers are suited for maize cultivation in semiarid areas of China. Therefore, we tested attapulgite-coated fertilizers. Attapulgite-coated fertilizers were prepared by dividing chemical fertilizers into three parts according to the nutrient demand of maize in its three main growth stages and coating each part with a layer of attapul...

  18. Seed quality and water use characteristics of maize landraces compared with selected commercial hybrids

    OpenAIRE

    Farai Mazvimbakupa; Albert Thembinkosi Modi; Tafadzwanashe Mabhaudhi

    2015-01-01

    Understanding seed quality and water use characteristics of maize (Zea mays L.) landraces will improve food security among subsistence farmers who still cultivate them. The objective of this study was to evaluate seed quality and water use characteristics of two maize landraces (GQ1 and GQ2) compared with two commercial hybrids (SC701 and PAN53). Seed quality was determined by the standard germination, electrical conductivity, and tetrazolium tests. A controlled environment study was conducte...

  19. Variability of factors that affect availability of iron, manganese and zinc in maize lines

    OpenAIRE

    Dragičević Vesna; Mladenović-Drinić Snežana; Stojiljković Milovan; Filipović Milomir; Dumanović Zoran; Kovačević Dragan

    2013-01-01

    Deficiencies of some mineral elements are causing serious health problems, which could be prevented by increase of mineral nutrients in food with supplementation, food fortification or plant breeding. From this point, experiment with 78 maize inbred lines was set up to determine maize lines with improved contents of Fe, Zn and Mn, as well as their relations with phytic acid, inorganic phosphorus and β-carotene, as factors which affect their absorption. Obta...

  20. Synthesis of raloxifene-chitosan conjugate: A novel chitosan derivative as a potential targeting vehicle.

    Science.gov (United States)

    Samadi, Fatemeh Yazdi; Mohammadi, Zohreh; Yousefi, Maryam; Majdejabbari, Sara

    2016-01-01

    Chitosan is a biocompatible, non-toxic and biodegradable biopolymer. Due to the presence of functional groups on its surface, it can be modified and used as a carrier in targeted drug/gene delivery systems. In this study, raloxifene (a selective estrogen receptor ligand) was conjugated to chitosan using different methods. The conjugates were investigated by means of FTIR, TGA and physical properties assessments. Cell viability was evaluated by XTT assay. FTIR and TGA results confirmed that the conjugation between chitosan and raloxifene occurred more efficiently when trimethyl chitosan in the presence of triethylamine and excess amount of linker was used. XTT assay on MCF-7 cell line illustrated that more than 80% of cells were viable after 24h exposure to selected molecules. These findings confirm that the conjugation of raloxifene-chitosan can occur successfully using special synthesis condition and this novel chitosan derivative can be introduced as a potential drug/gene targeting agent. PMID:26552018

  1. The effect of chitosan concentration on the electrical property of chitosan-blended cellulose electroactive paper

    International Nuclear Information System (INIS)

    We studied the effect of chitosan blending on the electrical property of chitosan-blended cellulose electroactive paper (EAPap) under different humidity conditions. As the chitosan blending ratio increased, the real part of the dielectric constant of chitosan-blended cellulose EAPap increased while the dielectric loss factor decreased. From the curve fitting of the measured data using an electrode polarization model, it was found that increasing the chitosan ratio in the EAPap might promote a decrease in the relaxation time of the EAPap, resulting in an increase of the ion mobility and dc conductivity. Over 30% of the chitosan blending ratio, a gradual increment of the ion mobility of the EAPap was observed at 40% relative humidity, while a quadratic increment of the mobility was found at 60% relative humidity condition. This kind of ion-mobility-enhanced cellulose EAPap can be used not only for bending actuators but also for medical applications such as blood clotting patches

  2. Chitosan-Coated Magnetic Nanoparticles with Low Chitosan Content Prepared in One-Step

    OpenAIRE

    Yolanda Osuna; Karla M. Gregorio-Jauregui; J. Gerardo Gaona-Lozano; de la Garza-Rodríguez, Iliana M.; Anna Ilyna; Enrique Díaz Barriga-Castro; Hened Saade; López, Raúl G.

    2012-01-01

    Chitosan-coated magnetic nanoparticles (CMNP) were obtained at 50°C in a one-step method comprising coprecipitation in the presence of low chitosan content. CMNP showed high magnetization and superparamagnetism. They were composed of a core of 9.5 nm in average diameter and a very thin chitosan layer in accordance with electron microscopy measurements. The results from Fourier transform infrared spectrometry demonstrated that CMNP were obtained and those from thermogravimetric analysis allowe...

  3. Adsorption of fucoidan and chitosan sulfate on chitosan modified PET films monitored by QCM-D

    OpenAIRE

    Indest, Tea; Laine, Janne; Johansson, Leena Sisko; Stana-Kleinschek, Karin; Strnad, Simona; Dworczak, Renate; Ribitsch, Volker

    2012-01-01

    The adsorption behavior of fucoidan as well as chitosan derivatives (chitosan sulfate) on poly(ethylene terephthalate) (PET) model film surface was studied using the quartz crystal microbalance technique. These systems were chosen for this study due to their promising biocompatible properties. Moreover, fucoidan and chitosan sulfate have promising anticoagulant properties and represent an alternative to heparin treatment of vascular grafts. As a first step, PET foils were activated by alkalin...

  4. Structure and Function of Chitosan (V). Conformations of Ethylene Glycol Derivatives of Chitin and Chitosan

    OpenAIRE

    YUI, Toshifumi; NAKATA, Kunihiko; OGAWA, Kozo

    1996-01-01

    Molecular structures of ethylene glycol derivatives of chitin and chitosan, where 0-6 of chitin chain was etherified and both 0-3 and 0-6 of chitosan were substituted, were studied by X-ray fiber diffraction methods coupled with conformational analyses. The extended two-fold helical conformations of both chitin and chitosan chains were retained even by the etherifications. Possible molecular conformations of these derivatives were proposed.

  5. Chitosan: a propitious biopolymer for drug delivery.

    Science.gov (United States)

    Duttagupta, Dibyangana S; Jadhav, Varsha M; Kadam, Vilasrao J

    2015-01-01

    Scientists have always been interested in the use of natural polymers for drug delivery. Chitosan, being a natural cationic polysaccharide has received a great deal of attention in the past few years. It is obtained by deacetylation of chitin and is regarded as the second most ubiquitous polymer subsequent to cellulose on earth. Unlike other natural polymers, the cationic charge possessed by chitosan is accountable for imparting interesting physical and chemical properties. Chitosan has been widely exploited for its mucoadhesive character, permeation enhancing properties and controlled release of drugs. Moreover it's non-toxic, biocompatible and biodegradable properties make it a good candidate for novel drug delivery system. This review provides an insight on various chitosan based formulations for drug delivery. Some of the current applications of chitosan in areas like ophthalmic, nasal, buccal, sublingual, gastro-retentive, pulmonary, transdermal, colon-specific and vaginal drug delivery have been discussed. In addition, active targeting of drugs to tumor cells using chitosan has been described. Lastly a brief section covering the safety aspects of chitosan has also been reviewed. PMID:25761010

  6. Development and characterization of biodegradable chitosan films containing two essential oils.

    Science.gov (United States)

    Shen, Zhu; Kamdem, Donatien Pascal

    2015-03-01

    Active biodegradable films from chitosan containing 10% to 30% w/w of citronella essential oil (CEO) and cedarwood oil (CWO) were developed by casting and solvent-evaporation method, and their physical, mechanical and thermal properties were investigated. Possible interactions between the chitosan chains and the essential oils were confirmed using Fourier-transform infrared spectroscopy (FTIR). Various amounts of CEO or CWO had significant effects on the films' mechanical properties, with the exception of 10% of CEO, which did not significantly affect the tensile strength of the films. The incorporation of the two tested oils provoked a remarkable reduction in the water-vapor permeability properties, with a decrease of about 63% when 30% CEO was added in chitosan films. Thermogravimetric analysis showed that degradation temperatures of the films containing CEO and CWO improved only slightly in comparison to control films without essential oils. FTIR spectra analysis provided some insights on the possible interactions between chitosan and the two essential oils used. This study suggests that active films can be developed by including CEO and CWO in a chitosan matrix. Such films can provide new formulation options for packaging industries in developing active packaging with potential food-technology applications. PMID:25542174

  7. Chitosan/TPP Nanoparticles as a Gene Delivery Agent For Tumor Suppressant P53

    Science.gov (United States)

    Liu, Gaojun

    In the last decade, non-viral polymeric vectors have become more attractive than their viral counterparts due to their nontoxicity and good biocompatibility. However, one of the major drawbacks is the low transfection efficiency when compared to viruses. In this work, a naturally cationic polysaccharide, chitosan, was cross-linked with negatively charged tripolyphosphate (TPP) to synthesize chitosan/TPP nanoparticles (CNPs) for delivery of plasmid DNA (pDNA). Particle size and zeta potential were characterized for CNPs with chitosan-TPP mass ratios of 4:1 and 6:1 (w/w) using benchtop dynamic light scattering. And both potentiometric titration method and FTIR spectrometer were applied to measure the degree of deacetylation of chitosan. Release kinetics of a model protein (bovine serum albumin, BSA) showed a steady release that reached 7% after 6 days. Besides that, we also assessed the in vitro transfection efficiency of the CNP-pDNA system using fluorescence microscopy, as well as the effect of tumor suppressant p53. Later the release kinetics and encapsulation efficiency of plasmid DNA bound to the CNPs will be investigated. Additionally, we will try to improve the gene transfection efficiency in both MC3T3-E1 and osteosarcoma cells by applying Sonicator 740 therapeutic ultrasound. Key words: gene therapy, non-viral gene vector, chitosan/TPP nanoparticles, ionic gelation, p53.

  8. Effects of Hypoxia and Chitosan on Equine Umbilical Cord-Derived Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    D. J. Griffon

    2016-01-01

    Full Text Available Chitosan opens new perspectives in regenerative medicine as it enhances the properties of mesenchymal stem cells (MSCs through formation of spheroids. Hypoxia has also been proposed to enhance stemness and survival of MSCs after in vivo implantation. These characteristics are relevant to the development of an off-the-shelf source of allogenic cells for regenerative therapy of tendinopathies. Umbilical cord-derived MSCs (UCM-MSCs offer an abundant source of immature and immunoprivileged stem cells. In this study, equine UCM-MSCs (eqUCM-MSCs conditioned for 3 and 7 days on chitosan films at 5% oxygen were compared to eqUCM-MSCs under standard conditions. Equine UCM-MSCs formed spheroids on chitosan but yielded 72% less DNA than standard eqUCM-MSCs. Expression of Sox2, Oct4, and Nanog was 4 to 10 times greater in conditioned cells at day 7. Fluorescence-labeled cells cultured for 7 days under standard conditions or on chitosan films under hypoxia were compared in a bilateral patellar tendon defect model in rats. Fluorescence was present in all treated tendons, but the modulus of elasticity under tension was greater in tendons treated with conditioned cells. Chitosan and hypoxia affected cell yield but improved the stemness of eqUCM-MSCs and their contribution to the healing of tissues. Given the abundance of allogenic cells, these properties are highly relevant to clinical applications and outweigh the negative impact on cell proliferation.

  9. Behavior of MC3T3-E1 Osteoblast Cultured on Chitosan Modified with Polyvinylpyrrolidone

    Institute of Scientific and Technical Information of China (English)

    XI Jing; GAO Yuan; KONG Lijun; GONG Yandao; ZHAO Nanming; ZHANG Xiufang

    2005-01-01

    The physical and chemical properties of four kinds of modified chitosan materials made by blending chitosan with polyvinylpyrrolidone (PVP) were investigated. All four of these modified chitosan materials were hydrophilic with water contact angles ranging from 59° to 69°. Fourier transform-infrared spectra of the modified materials showed a new band at 1288 cm-1, implying formation of a surface physical interpenetrating network structure. Enzyme linked immunosorbent assay results indicated that much less fibronectin was adsorbed on the modified materials than on only chitosan. The viability of MC3T3-E1 osteoblasts cultured on the materials was assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl- 2H-tetrazolium bromide assay. The results show that adding PVP10000 into the chitosan promotes adhesion of MC3T3-E1 osteoblasts on the modified materials, but has no effect on cell growth and proliferation; while adding PVP40000 reduces cell adhesion, growth, and proliferation. The results suggest that the increased hydrophilicity of the material surface does not always improve its biocompatibility, which will influence the selection and design of biomaterials.

  10. Antimicrobial Activities of Nisin, Tea Polyphenols, and Chitosan and their Combinations in Chilled Mutton.

    Science.gov (United States)

    He, Li; Zou, Likou; Yang, Qianru; Xia, Jinghua; Zhou, Kang; Zhu, Yuanting; Han, Xinfeng; Pu, Biao; Hu, Bin; Deng, Wenwen; Liu, Shuliang

    2016-06-01

    Antimicrobial activities of nisin, tea polyphenols (TPs), and chitosan, and their combinations were evaluated against both Gram-positive bacteria (GPB) and Gram-negative bacteria (GNB) by the agar dilution method. Results showed that the MIC of nisin was 2.44 to 1250 mg/L for GPB and reached 5000 mg/L for GNB. The MICs of TPs and chitosan were 313 to 625 mg/L and 469 mg/L for GNB, and 156 to 5000 mg/L and 234 to 938 mg/L for GPB, respectively. These results indicated that TPs and chitosan exhibited inhibitory effects against both GPB and GNB, whereas nisin inhibited the growth of GPB only. Based on the orthogonal test of their MICs, and evaluation of preservative effect and sensory attributes in chilled mutton, the optimum combination was chosen as 0.625, 0.313, and 3.752 g/L for nisin, TPs, and chitosan, respectively. By using the optimum treatment, the shelf life of chilled mutton was extended from 6 to 18 d at 4 °C in the preservative film packages. These results indicate that the combination of nisin, TPs, and chitosan could be used as preservatives to efficiently inhibit the growth of spoilage microorganisms and pathogens in meat, thus improving the safety and shelf life of chilled mutton. PMID:27096939

  11. Structural analysis, and antioxidant and antibacterial properties of chitosan-poly (vinyl alcohol) biodegradable films.

    Science.gov (United States)

    Hajji, Sawssen; Chaker, Achraf; Jridi, Mourad; Maalej, Hana; Jellouli, Kemel; Boufi, Sami; Nasri, Moncef

    2016-08-01

    The development and characterization of biodegradable blend films based on chitosan and poly (vinyl alcohol) for possible use in a variety of biological activities are reported. Fourier transform infrared spectroscopy (FTIR) spectra of chitosan-poly (vinyl alcohol) (Ch/PVA) films showed characteristics peaks shifting to a lower frequency range due to hydrogen bonding between -OH of PVA and -NH2 of chitosan. The chitosan and PVA polymers presented good compatibility. The morphology study of chitosan and composite films showed a compact and homogenous structure. The tensile strength and elongation at break increased with PVA content. In fact, the highest tensile strength and elongation at break (53.58 MPa and 454 %) occurs with pure PVA film. The results showed that PVA incorporation in the blends contributes to increase the intermolecular interactions, thus improving the mechanical properties. In addition, the prepared films demonstrated high antioxidant activities monitored by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging, reducing power, and β-carotene bleaching activity. Nevertheless, PVA addition reduced antioxidant and antibacterial activities against Gram-positive and Gram-negative bacteria tested. PMID:27106077

  12. Chitosan and its oligosaccharide derivatives (chito-oligosaccharides) as feed supplements in poultry and swine nutrition.

    Science.gov (United States)

    Swiatkiewicz, S; Swiatkiewicz, M; Arczewska-Wlosek, A; Jozefiak, D

    2015-02-01

    Chitosan is a non-toxic polyglucosamine, widespread in nature, which is deacetylated to varying degrees form of chitin, a component of exoskeleton of shrimps, crabs and insects. Because chitosan contains reactive functional groups, that is, amino acids and hydroxyl groups, it is characterised by antimicrobial, anti-inflammatory, anti-oxidative, antitumor, immunostimulatory and hypocholesterolemic properties when fed as dietary additive for farm animals. This article reviews and discusses the results of studies on the effects of dietary chitosan and its oligosaccharide derivatives on performance and metabolic response in poultry and pigs, that is, haematological, biochemical and immunological blood characteristics, microbiological profile of intestines, intestinal morphology and digestibility of nutrients, as well as on the quality of meat and eggs. The results of most of the experiments presented in this review indicate that chitosan used as a feed additive for poultry and pigs has some beneficial, biological effects, including immunomodulatory, anti-oxidative, antimicrobial and hypocholesterolemic properties. These properties of chitosan, unlike many other kinds of feed additives, were often reflected in improved growth performance (body weight gain and/or feed conversion ratio) of young animals, that is, broiler chickens and weaned pigs. PMID:25041091

  13. Aldehyde dehydrogenase protein superfamily in maize.

    Science.gov (United States)

    Zhou, Mei-Liang; Zhang, Qian; Zhou, Ming; Qi, Lei-Peng; Yang, Xiong-Bang; Zhang, Kai-Xuan; Pang, Jun-Feng; Zhu, Xue-Mei; Shao, Ji-Rong; Tang, Yi-Xiong; Wu, Yan-Min

    2012-11-01

    Maize (Zea mays ssp. mays L.) is an important model organism for fundamental research in the agro-biotechnology field. Aldehydes were generated in response to a suite of environmental stresses that perturb metabolism including salinity, dehydration, desiccation, and cold and heat shock. Many biologically important aldehydes are metabolized by the superfamily of NAD(P)(+)-dependent aldehyde dehydrogenases. Here, starting from the database of Z. mays, we identified 28 aldehyde dehydrogenase (ALDH) genes and 48 transcripts by the in silico cloning method using the ALDH-conserved domain amino acid sequence of Arabidopsis and rice as a probe. Phylogenetic analysis shows that all 28 members of the ALDH gene families were classified to ten distinct subfamilies. Microarray data and quantitative real-time PCR analysis reveal that ZmALDH9, ZmALDH13, and ZmALDH17 genes involve the function of drought stress, acid tolerance, and pathogens infection. These results suggested that these three ZmALDH genes might be potentially useful in maize genetic improvement. PMID:22983498

  14. Status of Maize Technologies Adoption in Kisii Highlands of Kenya

    International Nuclear Information System (INIS)

    Maize is an important crop for the majority of the Kenyan population and is grown both in the low and high potential areas. It is grown by more than 90% of the smallholder farm families and is estimated to contribute more than 20% of the total agricultural production. Average maize yield in southwest Kenya is 2.5 t ha-1 which is far below the research achieved yields of 8 t ha-1. Farmers in the region have continued to grow maize under poor husbandry practices, minimal application of inputs and poor management. Formal and informal surveys were used for data gathering. The multi-stage sampling technique was used to sample survey units in Agroecological upper midland (UM1) and lower highland (LH1) both in the high potential areas of the region. Selected farmers were stratified according to resource base, sex of household head and the AEZ. Results indicated that components of maize technology package (varieties, inorganic fertilizers, pests/diseases, seedbed preparation and weed control) were at various stages of adoption. The most adopted components were use of improved hybrid seed, planting in rows and maintenance of recommended plant population. The most identified reason for non use of organic fertilizer was high cost. The limited use of inputs was aggravated by the liberalised state of inputs markets while the output market was imperfect and did not support the producer. Tough farmyard manure and compost are locally available alternatives, very few of the interviewed farmers used them. To further understand the adoption process, regression analysis of factors that influence the use of fertilizer on maize production was done. The results of the study will be used to improve and/or modify the existing technologies to conform to farmers' circumstances and needs as well as provide feedback to policy formulators

  15. Field-evolved resistance to Bt maize by western corn rootworm.

    Directory of Open Access Journals (Sweden)

    Aaron J Gassmann

    Full Text Available BACKGROUND: Crops engineered to produce insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt are planted on millions of hectares annually, reducing the use of conventional insecticides and suppressing pests. However, the evolution of resistance could cut short these benefits. A primary pest targeted by Bt maize in the United States is the western corn rootworm Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae. METHODOLOGY/PRINCIPAL FINDINGS: We report that fields identified by farmers as having severe rootworm feeding injury to Bt maize contained populations of western corn rootworm that displayed significantly higher survival on Cry3Bb1 maize in laboratory bioassays than did western corn rootworm from fields not associated with such feeding injury. In all cases, fields experiencing severe rootworm feeding contained Cry3Bb1 maize. Interviews with farmers indicated that Cry3Bb1 maize had been grown in those fields for at least three consecutive years. There was a significant positive correlation between the number of years Cry3Bb1 maize had been grown in a field and the survival of rootworm populations on Cry3Bb1 maize in bioassays. However, there was no significant correlation among populations for survival on Cry34/35Ab1 maize and Cry3Bb1 maize, suggesting a lack of cross resistance between these Bt toxins. CONCLUSIONS/SIGNIFICANCE: This is the first report of field-evolved resistance to a Bt toxin by the western corn rootworm and by any species of Coleoptera. Insufficient planting of refuges and non-recessive inheritance of resistance may have contributed to resistance. These results suggest that improvements in resistance management and a more integrated approach to the use of Bt crops may be necessary.

  16. Cytocompatibility of chitosan and collagen-chitosan scaffolds for tissue engineering

    Directory of Open Access Journals (Sweden)

    Ligia L. Fernandes

    2011-01-01

    Full Text Available In this work, chitosan and collagen-chitosan porous scaffolds were produced by the freeze drying method and characterized as potential skin substitutes. Their beneficial effects on soft tissues justify the choice of both collagen and chitosan. Samples were characterized using scanning electron microscope, Fourier Transform InfraRed Spectroscopy (FTIR and thermogravimetry (TG. The in vitro cytocompatibility of chitosan and collagen-chitosan scaffolds was evaluated with three different assays. Phenol and titanium powder were used as positive and negative controls, respectively. Scanning electron microscopy revealed the highly interconnected porous structure of the scaffolds. The addition of collagen to chitosan increased both pore diameter and porosity of the scaffolds. Results of FTIR and TG analysis indicate that the two polymers interact yielding a miscible blend with intermediate thermal degradation properties. The reduction of XTT ((2,3-bis[2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide and the uptake of Neutral Red (NR were not affected by the blend or by the chitosan scaffold extracts, but the blend and the titanium powder presented greater incorporation of Crystal Violet (CV than phenol and chitosan alone. In conclusion, collagen-chitosan scaffolds produced by freeze-drying methods were cytocompatible and presented mixed properties of each component with intermediate thermal degradation properties.

  17. Small angle Neutron Scatteringanalysis of chitosan in different phases

    International Nuclear Information System (INIS)

    Biopolymers are studied extensively due to its wide applications in the field of bio-technology, micro fluidics and lab on chip devices. Chitosan is natural biopolymer derived from chitin. It has wide applications in bio-medical engineering because of its biocompatibility and biodegradability. Also, chitosan act as reducing and stabilizing agent for the metal ions. Chitosan is also a good candidate in batteries as membranes. It is therefore important to study the conformational changes of chitosan. In this research work, we used SANS to understand the modifications in the radius of gyration (Rg) values of chitosan polymer in solution and in presence of HAuCl4 and LiClO4. Chitosan solution became a gel in the presence of HAuCl4 enabling to study the associated conformational change in chitosan in gels. We have also made films of chitosan, chitosan- Au and Chitosan- LiClO4 and studied the associated conformational changes in chitosan. Gels and films were formed by varying the concentration of HAuCl4. Lower concentration of HAuCl4 gave films while higher concentration of HAuCl4 gave gels. The Imaging was carried out for the samples using TEM and SEM. SANS shows that the chitosan solution (liquid) had greater Rg value than the chitosan film. The Rg value did not change in gels from that of solution. There was no correlation length for the fitting for chitosan in solution, however there was correlation length observed in the gels. This indicates that in gels the chitosan units are more localized than in solution phase. Interestingly, chitosan-Au-Li film shows the formation of star like structures which are not observed in case of gels. Hence we conclude that the presence of Lithium can induce conformational changes in chitosan films while HAuCl4 can localize chitosan units in solution leading to formation of gels.

  18. Chitosan-Pectin Synergistic Interaction and Gelation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Mixed gels of chitosan-pectin were prepared by varying the ratio of constituents in the presence of NaCl. Mixed gel at 3% of total polysaccharide concentration with addtion of 12% NaCl showed a synergistic maximum when the ratio of chitosan to pectin was 60 : 40. The effect of the polysaccharide concentration,the preparation temperature(Tp), the time of incubation, balk salt concentration, the molecular weight and the degree of deacetylation of chitosan on gelation have been studied. Interaction mechanism between molecules of both polysaccharides was investigated by FT-IR spectrometry.

  19. Adsorption of Cadmium By Silica Chitosan

    OpenAIRE

    Moftah Ali; Ani Mulyasuryani; Akhmad Sabarudin

    2013-01-01

    The adsorption process depends on initial concentration of Cd2+ and ratio of  chitosan in adsorbent. The present study deals with the competitive adsorption of Cd2+ ion onto silica graft with chitosan. Batch adsorption experiments were performed at five different initial Cd2+ concentrations (5, 10, 15, 20 and 25 ppm), on five different proportion from silica to chitosan (100%, 95%, 85%, 75% and 65%) as adsorbent at pH 5. In the recovery process, the high recovery at 0.5 mg and observed the re...

  20. Chitosan Conduit for Peripheral Nerve Regeneration

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Chitosan, the N-deacetylated form of chitin, has good biocompatibility and biodegradability.This paper investigates the feasibility of using chitosan conduits for peripheral nerve regeneration.Cell culture experiments were used to test the material's cytotoxicity and affinity to nerve cells.Conduit implantation experiments were used to study the degradation of the material and the regeneration of injured sciatic nerves.The primary results indicate that chitosan has good mechanical properties, biocompatibility, and biodegradability and it may be a promising biomaterial for peripheral nerve regeneration.