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Sample records for targeted gadolinium-loaded chitosan

  1. Gadolinium-loaded chitosan nanoparticles for cancer neutron-capture therapy. Pharmaceutical characteristics and in vitro antitumor effect

    International Nuclear Information System (INIS)

    Fukumori, Yoshinobu; Ichikawa, Hideki; Nakatani, Yugo

    2006-01-01

    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)

  2. In vitro study of novel gadolinium-loaded liposomes guided by GBI-10 aptamer for promising tumor targeting and tumor diagnosis by magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Gu MJ

    2015-08-01

    Full Text Available Meng-Jie Gu,1,* Kun-Feng Li,1,* Lan-Xin Zhang,1 Huan Wang,1 Li-Si Liu,2 Zhuo-Zhao Zheng,2 Nan-Yin Han,1 Zhen-Jun Yang,1 Tian-Yuan Fan1 1State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 2Department of Radiology, Peking University Third Hospital, Beijing, People’s Republic of China *These authors contributed equally to this work Abstract: Novel gadolinium-loaded liposomes guided by GBI-10 aptamer were developed and evaluated in vitro to enhance magnetic resonance imaging (MRI diagnosis of tumor. Nontargeted gadolinium-loaded liposomes were achieved by incorporating amphipathic material, Gd (III [N,N-bis-stearylamidomethyl-N'-amidomethyl] diethylenetriamine tetraacetic acid, into the liposome membrane using lipid film hydration method. GBI-10, as the targeting ligand, was then conjugated onto the liposome surface to get GBI-10-targeted gadolinium-loaded liposomes (GTLs. Both nontargeted gadolinium-loaded liposomes and GTLs displayed good dispersion stability, optimal size, and zeta potential for tumor targeting, as well as favorable imaging properties with enhanced relaxivity compared with a commercial MRI contrast agent (CA, gadopentetate dimeglumine. The use of GBI-10 aptamer in this liposomal system was intended to result in increased accumulation of gadolinium at the periphery of C6 glioma cells, where the targeting extracellular matrix protein tenascin-C is overexpressed. Increased cellular binding of GTLs to C6 cells was confirmed by confocal microscopy, flow cytometry, and MRI, demonstrating the promise of this novel delivery system as a carrier of MRI contrast agent for the diagnosis of tumor. These studies provide a new strategy furthering the development of nanomedicine for both diagnosis and therapy of tumor. Keywords: magnetic resonance imaging, gadolinium, liposomes, tenascin-C, GBI-10 aptamer, tumor targeting

  3. Targeted gadolinium-loaded dendrimer nanoparticles for tumor-specific magnetic resonance contrast enhancement

    Directory of Open Access Journals (Sweden)

    Scott D Swanson

    2008-06-01

    Full Text Available Scott D Swanson1, Jolanta F Kukowska-Latallo2, Anil K Patri5, Chunyan Chen6, Song Ge4, Zhengyi Cao3, Alina Kotlyar3, Andrea T East7, James R Baker31Department of Radiology, The University of Michigan Medical School, 2Department of Internal Medicine, The University of Michigan Medical School, 3Michigan Nanotechnology Institute for Medicine and Biological Sciences, The University of Michigan, 4Applied Physics, The University of Michigan, MD, USA; 5Present address: National Cancer Institute at Frederick (Contractor, MD, USA; 6Present address: Intel Corporation, Chandler, AZ, USA; 7Present address: Stritch School of Medicine, Chicago, ILL, USAAbstract: A target-specific MRI contrast agent for tumor cells expressing high affinity folate receptor was synthesized using generation five (G5 of polyamidoamine (PAMAM dendrimer. Surface modified dendrimer was functionalized for targeting with folic acid (FA and the remaining terminal primary amines of the dendrimer were conjugated with the bifunctional NCS-DOTA chelator that forms stable complexes with gadolinium (Gd III. Dendrimer-DOTA conjugates were then complexed with GdCl3, followed by ICP-OES as well as MRI measurement of their longitudinal relaxivity (T1 s−1 mM−1 of water. In xenograft tumors established in immunodeficient (SCID mice with KB human epithelial cancer cells expressing folate receptor (FAR, the 3D MRI results showed specific and statistically significant signal enhancement in tumors generated with targeted Gd(III-DOTA-G5-FA compared with signal generated by non-targeted Gd(III-DOTA-G5 contrast nanoparticle. The targeted dendrimer contrast nanoparticles infiltrated tumor and were retained in tumor cells up to 48 hours post-injection of targeted contrast nanoparticle. The presence of folic acid on the dendrimer resulted in specific delivery of the nanoparticle to tissues and xenograft tumor cells expressing folate receptor in vivo. We present the specificity of the dendrimer

  4. Structure and properties of gadolinium loaded calcium phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Cuiling [Analytical and Testing Center, Southwest University of Science and Technology, Mianyang 621010 (China); State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); Liang, Xiaofeng, E-mail: XFLiang@swust.edu.cn [Analytical and Testing Center, Southwest University of Science and Technology, Mianyang 621010 (China); State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); Li, Haijian; Yu, Huijun; Li, Zhen [Analytical and Testing Center, Southwest University of Science and Technology, Mianyang 621010 (China); State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); Yang, Shiyuan [State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China)

    2014-10-15

    The glass samples with composition xGd{sub 2}O{sub 3}–(50 − x)CaO–50P{sub 2}O{sub 5} (0 ⩽ x ⩽ 9 mol%) were prepared by the conventional melt quench method. The structure and properties of gadolinium loaded in calcium phosphate glasses were investigated using XRD, SEM, DTA, IR and Raman spectroscopy. The XRD and SEM analysis for the samples show that the majority of samples are amorphous, and crystallization occurs when the content of Gd{sub 2}O{sub 3} containing is up to 6 mol%. Two main crystalline phases, Ca{sub 2}P{sub 2}O{sub 7} and Gd{sub 3}(P{sub 2}O{sub 7}){sub 3}, are embedded in an amorphous matrix. IR and Raman data indicate that glass structure consists of predominantly metaphosphate (Q{sup 2}) units and the depolymerization of phosphate network with the addition of Gd{sub 2}O{sub 3}. Both the chemical durability and the glass transition temperature (T{sub g}) are improved with the increase of Gd{sub 2}O{sub 3}, which suggests that the Gd acts a role of strengthening the cross-links between the phosphate chains of the glass.

  5. Structure and properties of gadolinium loaded calcium phosphate glasses

    International Nuclear Information System (INIS)

    Wang, Cuiling; Liang, Xiaofeng; Li, Haijian; Yu, Huijun; Li, Zhen; Yang, Shiyuan

    2014-01-01

    The glass samples with composition xGd 2 O 3 –(50 − x)CaO–50P 2 O 5 (0 ⩽ x ⩽ 9 mol%) were prepared by the conventional melt quench method. The structure and properties of gadolinium loaded in calcium phosphate glasses were investigated using XRD, SEM, DTA, IR and Raman spectroscopy. The XRD and SEM analysis for the samples show that the majority of samples are amorphous, and crystallization occurs when the content of Gd 2 O 3 containing is up to 6 mol%. Two main crystalline phases, Ca 2 P 2 O 7 and Gd 3 (P 2 O 7 ) 3 , are embedded in an amorphous matrix. IR and Raman data indicate that glass structure consists of predominantly metaphosphate (Q 2 ) units and the depolymerization of phosphate network with the addition of Gd 2 O 3 . Both the chemical durability and the glass transition temperature (T g ) are improved with the increase of Gd 2 O 3 , which suggests that the Gd acts a role of strengthening the cross-links between the phosphate chains of the glass

  6. Novel chitosan coated magnetic nanocarriers for the targeted Diclofenac delivery.

    Science.gov (United States)

    Agotegaray, Mariela; Palma, Santiago; Lassalle, Verónica

    2014-05-01

    New magnetic devices consisting of magnetite functionalized with oleic acid and chitosan have been synthesized and employed to the loading of Diclofenac as potential tool for treatment of targeted inflammatory diseases. Magnetic loaded and un-loaded nanoparticles have been thoroughly characterized by infrared spectroscopy, transmission electron microscopy, determination of hydrodynamic diameter by Dynamic light scattering and zeta potential measurements at different pH conditions. A study of the release of Diclofenac has been performed in vitro and available mathematical models have been used to determine the release kinetic. Both properties and release data reveal that this nanomagnetic platform would be suitable for in vivo assays.

  7. Integrin αvβ3–Targeted Dynamic Contrast–Enhanced Magnetic Resonance Imaging Using a Gadolinium-Loaded Polyethylene Gycol–Dendrimer–Cyclic RGD Conjugate to Evaluate Tumor Angiogenesis and to Assess Early Antiangiogenic Treatment Response in a Mouse Xenograft Tumor Model

    Directory of Open Access Journals (Sweden)

    Wei-Tsung Chen

    2012-07-01

    Full Text Available The purpose of this study was to validate an integrin αvβ3–targeted magnetic resonance contrast agent, PEG-G3-(Gd-DTPA6-(cRGD-DTPA2, for its ability to detect tumor angiogenesis and assess early response to antiangiogenic therapy using dynamic contrast–enhanced (DCE magnetic resonance imaging (MRI. Integrin αvβ3–positive U87 cells and control groups were incubated with fluorescein-labeled cRGD-conjugated dendrimer, and the cellular attachment of the dendrimer was observed. DCE MRI was performed on mice bearing KB xenograft tumors using either PEG-G3-(Gd-DTPA6-(cRGD-DTPA2 or PEG-G3-(Gd-DTPA6-(cRAD-DTPA2. DCE MRI was also performed 2 hours after anti–integrin αvβ3 monoclonal antibody treatment and after bevacizumab treatment on days 3 and 6t. Using DCE MRI, the 30-minute contrast washout percentage was significantly lower in the cRGD-conjugate injection groups. The enhancement patterns were different between the two contrast injection groups. In the antiangiogenic therapy groups, a rapid increase in 30-minute contrast washout percentage was observed in both the LM609 and bevacizumab treatment groups, and this occurred before there was an observable decrease in tumor size. The integrin αvβ3 targeting ability of PEG-G3-(Gd-DTPA6-(cRGD-DTPA2 in vitro and in vivo was demonstrated. The 30-minute contrast washout percentage is a useful parameter for examining tumor angiogenesis and for the early assessment of antiangiogenic treatment response.

  8. Targeting to carcinoma cells with chitosan- and starch-coated magnetic nanoparticles for magnetic hyperthermia.

    Science.gov (United States)

    Kim, Dong-Hyun; Kim, Kyoung-Nam; Kim, Kwang-Mahn; Lee, Yong-Keun

    2009-01-01

    The delivery of hyperthermic thermoseeds to a specific target site with minimal side effects is an important challenge in targeted hyperthermia, which employs magnetic method and functional polymers. An external magnetic field is used to control the site-specific targeting of the magnetic nanoparticles. Polymer-coated magnetic nanoparticles can confer a higher affinity to the biological cell membranes. In this study, uncoated, chitosan-coated, and starch-coated magnetic nanoparticles were synthesized for use as a hyperthermic thermoseed. Each sample was examined with respect to their applications to hyperthermia using XRD, VSM, and FTIR. In addition, the temperature changes under an alternating magnetic field were observed. As in vitro tests, the magnetic responsiveness of chitosan- and starch-coated magnetite was determined by a simple blood vessel model under various intensities of magnetic field. L929 normal cells and KB carcinoma cells were used to examine the cytotoxicity and affinity of each sample using the MTT method. The chitosan-coated magnetic nanoparticles generated a higher DeltaT of 23 degrees C under an AC magnetic field than the starch-coated magnetite, and the capturing rate of the particles was 96% under an external magnetic field of 0.4 T. The highest viability of L929 cells was 93.7%. Comparing the rate of KB cells capture with the rate of L929 cells capture, the rate of KB cells capture relatively increased with 10.8% in chitosan-coated magnetic nanoparticles. Hence, chitosan-coated magnetic nanoparticles are biocompatible and have a selective affinity to KB cells. The targeting of magnetic nanoparticles in hyperthermia was improved using a controlled magnetic field and a chitosan-coating. Therefore, chitosan-coated magnetic nanoparticles are expected to be promising materials for use in magnetic targeted hyperthermia. 2008 Wiley Periodicals, Inc.

  9. Dual responsive PNIPAM–chitosan targeted magnetic nanopolymers for targeted drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Yadavalli, Tejabhiram, E-mail: tejabhiram@gmail.com [Nanotechnology Research Centre, SRM University, Chennai 603203 (India); Ramasamy, Shivaraman [Nanotechnology Research Centre, SRM University, Chennai 603203 (India); School of Physics, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009 (Australia); Chandrasekaran, Gopalakrishnan; Michael, Isaac; Therese, Helen Annal [Nanotechnology Research Centre, SRM University, Chennai 603203 (India); Chennakesavulu, Ramasamy [Department of Pharmacy practice, SRM College of Pharmacy, Chennai 603203 (India)

    2015-04-15

    A dual stimuli sensitive magnetic hyperthermia based drug delivery system has been developed for targeted cancer treatment. Thermosensitive amine terminated poly-N-isopropylacrylamide complexed with pH sensitive chitosan nanoparticles was prepared as the drug carrier. Folic acid and fluorescein were tagged to the nanopolymer complex via N-hydroxysuccinimide and ethyl-3-(3-dimethylaminopropyl)carbodiimide reaction to form a fluorescent and cancer targeting magnetic carrier system. The formation of the polymer complex was confirmed using infrared spectroscopy. Gadolinium doped nickel ferrite nanoparticles prepared by a hydrothermal method were encapsulated in the polymer complex to form a magnetic drug carrier system. The proton relaxation studies on the magnetic carrier system revealed a 200% increase in the T1 proton relaxation rate. These magnetic carriers were loaded with curcumin using solvent evaporation method with a drug loading efficiency of 86%. Drug loaded nanoparticles were tested for their targeting and anticancer properties on four cancer cell lines with the help of MTT assay. The results indicated apoptosis of cancer cell lines within 3 h of incubation. - Highlights: • The use of gadolinium doped nickel ferrite with the suggested doping level. • The use of PNIPMA–chitosan polymer with folic acid and fluorescein as a drug carrier complex. • Magnetic hyperthermia studies of gadolinium doped nickel ferrites are being reported for the first time. • Proton relaxivity studies which indicate the MRI contrasting properties on the reported system are new. • Use of curcumin, a hydrophobic Indian spice as a cancer killing agent inside the reported magnetic polymer complex.

  10. Chitosan-based DNA delivery vector targeted to gonadotropin-releasing hormone (GnRH) receptor.

    Science.gov (United States)

    Boonthum, Chatwalee; Namdee, Katawut; Boonrungsiman, Suwimon; Chatdarong, Kaywalee; Saengkrit, Nattika; Sajomsang, Warayuth; Ponglowhapan, Suppawiwat; Yata, Teerapong

    2017-02-10

    The main purpose of this study was to investigate the application of modified chitosan as a potential vector for gene delivery to gonadotropin-releasing hormone receptor (GnRHR)-expressing cells. Such design of gene carrier could be useful in particular for gene therapy for cancers related to the reproductive system, gene disorders of sexual development, and contraception and fertility control. In this study, a decapeptide GnRH was successfully conjugated to chitosan (CS) as confirmed by proton nuclear magnetic resonance spectroscopy ( 1 H NMR) and Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The synthesized GnRH-conjugated chitosan (GnRH-CS) was able to condense DNA to form positively charged nanoparticles and specifically deliver plasmid DNA to targeted cells in both two-dimensional (2D) and three-dimensional (3D) cell cultures systems. Importantly, GnRH-CS exhibited higher transfection activity compared to unmodified CS. In conclusion, GnRH-conjugated chitosan can be a promising carrier for targeted DNA delivery to GnRHR-expressing cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Magnetic chitosan nanoparticles as a drug delivery system for targeting photodynamic therapy

    International Nuclear Information System (INIS)

    Sun Yun; Chen Zhilong; Yang Xiaoxia; Huang Peng; Zhou Xinping; Du Xiaoxia

    2009-01-01

    Photodynamic therapy (PDT) has become an increasingly recognized alternative to cancer treatment in clinic. However, PDT therapy agents, namely photosensitizer (PS), are limited in application as a result of prolonged cutaneous photosensitivity, poor water solubility and inadequate selectivity, which are encountered by numerous chemical therapies. Magnetic chitosan nanoparticles provide excellent biocompatibility, biodegradability, non-toxicity and water solubility without compromising their magnetic targeting. Nevertheless, no previous attempt has been reported to develop an in vivo magnetic drug delivery system with chitosan nanoparticles for magnetic resonance imaging (MRI) monitored targeting photodynamic therapy. In this study, magnetic targeting chitosan nanoparticles (MTCNPs) were prepared and tailored as a drug delivery system and imaging agents for PS, designated as PHPP. Results showed that PHPP-MTCNPs could be used in MRI monitored targeting PDT with excellent targeting and imaging ability. Non-toxicity and high photodynamic efficacy on SW480 carcinoma cells both in vitro and in vivo were achieved with this method at the level of 0-100 μM. Notably, localization of nanoparticles in skin and hepatic tissue was significantly less than in tumor tissue, therefore photosensitivity and hepatotoxicity can be attenuated.

  12. PEGylated chitosan grafted with polyamidoaminedendron as tumor-targeted magnetic resonance imaging contrast agent

    International Nuclear Information System (INIS)

    Guangyue Zu; Xiaoyan Tong; Yi Cao; Ye Kuang; Yajie Zhang; Min Liu; Renjun Pei

    2017-01-01

    Macromolecular contrast agents labeled with targeting ligands are now receiving growing interest in tumor-targeted magnetic resonance imaging. In this study, a macromolecular contrast agent based on PEGylated chitosan was synthesized and characterized, and its application as an MRI contrast agent was then demonstrated both in vitro and in vivo. First, the chitosan backbone was partially grafted with poly(ethylene glycol), which was used to improve the in vivo stability, followed by modifying with azide groups. Second, alkynyl-terminated PAMAM dendron modified with gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) was synthesized and conjugated onto the chitosan backbone through click chemistry. Finally, the obtained mCA was further functionalized with folic acid to improve the target specificity. The obtained FA labeled mCA exhibited higher relaxivity (9.53 mM"-"1.s"-"1) relative to Gd-DTPA (4.25 mM"-"1.s"-"1) and showed negligible toxicity as determined by the WST assay. In vivo MRI results suggested that a relatively high signal enhancement was observed in the tumor region, which made it a promising candidate for tumor-targeted MRI CA. (authors)

  13. Dendritic Cell Targeted Chitosan Nanoparticles for Nasal DNA Immunization against SARS CoV Nucleocapsid Protein

    OpenAIRE

    Raghuwanshi, Dharmendra; Mishra, Vivek; Das, Dipankar; Kaur, Kamaljit; Suresh, Mavanur R.

    2012-01-01

    This work investigates the formulation and in vivo efficacy of dendritic cell (DC) targeted plasmid DNA loaded biotinylated chitosan nanoparticles for nasal immunization against nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus (SARS-CoV) as antigen. The induction of antigen-specific mucosal and systemic immune response at the site of virus entry is a major challenge for vaccine design. Here, we designed a strategy for non-invasive receptor mediated gene delivery to na...

  14. Dendritic cell targeted chitosan nanoparticles for nasal DNA immunization against SARS CoV nucleocapsid protein.

    Science.gov (United States)

    Raghuwanshi, Dharmendra; Mishra, Vivek; Das, Dipankar; Kaur, Kamaljit; Suresh, Mavanur R

    2012-04-02

    This work investigates the formulation and in vivo efficacy of dendritic cell (DC) targeted plasmid DNA loaded biotinylated chitosan nanoparticles for nasal immunization against nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus (SARS-CoV) as antigen. The induction of antigen-specific mucosal and systemic immune response at the site of virus entry is a major challenge for vaccine design. Here, we designed a strategy for noninvasive receptor mediated gene delivery to nasal resident DCs. The pDNA loaded biotinylated chitosan nanoparticles were prepared using a complex coacervation process and characterized for size, shape, surface charge, plasmid DNA loading and protection against nuclease digestion. The pDNA loaded biotinylated chitosan nanoparticles were targeted with bifunctional fusion protein (bfFp) vector for achieving DC selective targeting. The bfFp is a recombinant fusion protein consisting of truncated core-streptavidin fused with anti-DEC-205 single chain antibody (scFv). The core-streptavidin arm of fusion protein binds with biotinylated nanoparticles, while anti-DEC-205 scFv imparts targeting specificity to DC DEC-205 receptor. We demonstrate that intranasal administration of bfFp targeted formulations along with anti-CD40 DC maturation stimuli enhanced magnitude of mucosal IgA as well as systemic IgG against N protein. The strategy led to the detection of augmented levels of N protein specific systemic IgG and nasal IgA antibodies. However, following intranasal delivery of naked pDNA no mucosal and systemic immune responses were detected. A parallel comparison of targeted formulations using intramuscular and intranasal routes showed that the intramuscular route is superior for induction of systemic IgG responses compared with the intranasal route. Our results suggest that targeted pDNA delivery through a noninvasive intranasal route can be a strategy for designing low-dose vaccines.

  15. Chitosan derivatives targeting lipid bilayers: Synthesis, biological activity and interaction with model membranes.

    Science.gov (United States)

    Martins, Danubia Batista; Nasário, Fábio Domingues; Silva-Gonçalves, Laiz Costa; de Oliveira Tiera, Vera Aparecida; Arcisio-Miranda, Manoel; Tiera, Marcio José; Dos Santos Cabrera, Marcia Perez

    2018-02-01

    The antimicrobial activity of chitosan and derivatives to human and plant pathogens represents a high-valued prospective market. Presently, two low molecular weight derivatives, endowed with hydrophobic and cationic character at different ratios were synthesized and characterized. They exhibit antimicrobial activity and increased performance in relation to the intermediate and starting compounds. However, just the derivative with higher cationic character showed cytotoxicity towards human cervical carcinoma cells. Considering cell membranes as targets, the mode of action was investigated through the interaction with model lipid vesicles mimicking bacterial, tumoral and erythrocyte membranes. Intense lytic activity and binding are demonstrated for both derivatives in anionic bilayers. The less charged compound exhibits slightly improved selectivity towards bacterial model membranes, suggesting that balancing its hydrophobic/hydrophilic character may improve efficiency. Observing the aggregation of vesicles, we hypothesize that the "charge cluster mechanism", ascribed to some antimicrobial peptides, could be applied to these chitosan derivatives. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Intraperitoneal administration of chitosan/DsiRNA nanoparticles targeting TNFα prevents radiation-induced fibrosis

    International Nuclear Information System (INIS)

    Nawroth, Isabel; Alsner, Jan; Behlke, Mark A.; Besenbacher, Flemming; Overgaard, Jens; Howard, Kenneth A.; Kjems, Jorgen

    2010-01-01

    Background and purpose: One of the most common and dose-limiting long-term adverse effects of radiation therapy is radiation-induced fibrosis (RIF), which is characterized by restricted tissue flexibility, reduced compliance or strictures, pain and in severe cases, ulceration and necrosis. Several strategies have been proposed to ameliorate RIF but presently no effective one is available. Recent studies have reported that tumor necrosis factor-α (TNFα) plays a role in fibrogenesis. Material and methods: Male CDF1 mice were radiated with a single dose of 45 Gy. Chitosan/DsiRNA nanoparticles targeting TNFα were intraperitoneal injected and late radiation-induced fibrosis (RIF) was assessed using a modification of the leg contracture model. Additionally, the effect of these nanoparticles on tumor growth and tumor control probability in the absence of radiation was examined in a C3H mammary carcinoma model. Results: We show in this work, that targeting TNFα in macrophages by intraperitoneal administration of chitosan/DsiRNA nanoparticles completely prevented radiation-induced fibrosis in CDF1 mice without revealing any cytotoxic side-effects after a long-term administration. Furthermore, such TNFα targeting was selective without any significant influence on tumor growth or irradiation-related tumor control probability. Conclusion: This nanoparticle-based RNAi approach represents a novel approach to prevent RIF with potential application to improve clinical radiation therapeutic strategies.

  17. Targeting experimental orthotopic glioblastoma with chitosan-based superparamagnetic iron oxide nanoparticles (CS-DX-SPIONs).

    Science.gov (United States)

    Shevtsov, Maxim; Nikolaev, Boris; Marchenko, Yaroslav; Yakovleva, Ludmila; Skvortsov, Nikita; Mazur, Anton; Tolstoy, Peter; Ryzhov, Vyacheslav; Multhoff, Gabriele

    2018-01-01

    Glioblastoma is the most devastating primary brain tumor of the central nervous system in adults. Magnetic nanocarriers may help not only for a targeted delivery of chemotherapeutic agents into the tumor site but also provide contrast enhancing properties for diagnostics using magnetic resonance imaging (MRI). Synthesized hybrid chitosan-dextran superparamagnetic nanoparticles (CS-DX-SPIONs) were characterized using transmission electron microscopy (TEM) and relaxometry studies. Nonlinear magnetic response measurements were employed for confirming the superparamagnetic state of particles. Following in vitro analysis of nanoparticles cellular uptake tumor targeting was assessed in the model of the orthotopic glioma in rodents. CS-DX-SPIONs nanoparticles showed a uniform diameter of 55 nm under TEM and superparamagentic characteristics as determined by T 1 (spin-lattice relaxation time) and T 2 (spin-spin relaxation time) proton relaxation times. Application of the chitosan increased the charge from +8.9 to +19.3 mV of the dextran-based SPIONs. The nonlinear magnetic response at second harmonic of CS-DX-SPIONs following the slow change of stationary magnetic fields with very low hysteresis evidenced superparamagnetic state of particles at ambient temperatures. Confocal microscopy and flow cytometry studies showed an enhanced internalization of the chitosan-based nanoparticles in U87, C6 glioma and HeLa cells as compared to dextran-coated particles. Cytotoxicity assay demonstrated acceptable toxicity profile of the synthesized nanoparticles up to a concentration of 10 μg/ml. Intravenously administered CS-DX-SPIONs in orthotopic C6 gliomas in rats accumulated in the tumor site as shown by high-resolution MRI (11.0 T). Retention of nanoparticles resulted in a significant contrast enhancement of the tumor image that was accompanied with a dramatic drop in T 2 values ( P chitosan-dextran magnetic particles demonstrated high MR contrast enhancing properties for the

  18. Chitosan nanoparticles for targeting and sustaining minoxidil sulphate delivery to hair follicles.

    Science.gov (United States)

    Matos, Breno Noronha; Reis, Thaiene Avila; Gratieri, Taís; Gelfuso, Guilherme Martins

    2015-04-01

    This work developed minoxidil sulphate-loaded chitosan nanoparticles (MXS-NP) for targeted delivery to hair follicles, which could sustain drug release and improve the topical treatment of alopecia. Chitosan nanoparticles were obtained using low-molecular weight chitosan and tripolyphosphate as crosslink agent. MXS-NP presented a monomodal distribution with hydrodynamic diameter of 235.5 ± 99.9 nm (PDI of 0.31 ± 0.01) and positive zeta potential (+38.6 ± 6.0 mV). SEM analysis confirmed nanoparticles average size and spherical shape. A drug loading efficiency of 73.0 ± 0.3% was obtained with polymer:drug ratio of 1:1 (w/w). Drug release through cellulose acetate membranes from MXS-NP was sustained in about 5 times in comparison to the diffusion rate of MXS from the solution (188.9 ± 6.0 μg/cm(2)/h and 35.4 ± 1.8 μg/cm(2)/h). Drug permeation studies through the skin in vitro, followed by selective recovery of MXS from the hair follicles, showed that MXS-NP application resulted in a two-fold MXS increase into hair follicles after 6h in comparison to the control solution (5.9 ± 0.6 μg/cm(2) and 2.9 ± 0.8 μg/cm(2)). MXS-loading in nanoparticles appears as a promising and easy strategy to target and sustain drug delivery to hair follicles, which may improve the topical treatment of alopecia. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Intracellular siRNA delivery dynamics of integrin-targeted, PEGylated chitosan-poly(ethylene imine) hybrid nanoparticles

    DEFF Research Database (Denmark)

    Ragelle, Héloïse; Colombo, Stefano; Pourcelle, Vincent

    2015-01-01

    chitosan-poly(ethylene imine) hybrid nanoparticles. The amount of intracellular siRNA delivered by αvβ3-targeted versus non-targeted nanoparticles was quantified in the human non-small cell lung carcinoma cell line H1299 expressing enhanced green fluorescent protein (EGFP) using a stem-loop reverse...... that these nanoparticles might end up in late endosomes or lysosomes without releasing their cargo to the cell cytoplasm. Thus, the silencing efficiency of the chitosan-based nanoparticles is strongly dependent on the uptake and the intracellular trafficking in H1299 EGFP cells, which is critical information towards...

  20. Effect of tween 80 on nanoparticle preparation of modified chitosan for targeted delivery of combination doxorubicin and curcumin analogue

    Science.gov (United States)

    Sukmawati, Anita; Utami, Wahyu; Yuliani, Ratna; Da'i, Muhammad; Nafarin, Akhmad

    2018-02-01

    Delivery of anticancer is facing several problems including unspecific delivery of active substance to the targeted cell. The conjugation between chitosan and folate (chitosan-FA) was used for nanoparticle preparation containing combination of doxorubicin (DOX) and curcumin analogue, 2,5-bis-(4-hydroxi,3,5-dimethyl)-benzylidincylopentanone, as active substances. The purpose of this research is investigating formulation aspect for chitosan-FA nanoparticle by addition various tween 80 to achieve desired nano-size particle. The ionic gelation method was used for nanoparticle preparation using 0.05% w/v chitosan-FA with addition of 0.1 and 0.5% v/v of tween 80. The result showed that the high concentration of tween 80 during nanoparticle preparation lead to formation of smaller size particle. The 111.8 ±4.11 nm particle size was revealed by addition of 0.5% v/v tween 80 during chitosan-FA nanoparticle preparation loaded with active substances.

  1. Pectin-zinc-chitosan-polyethylene glycol colloidal nano-suspension as a food grade carrier for colon targeted delivery of resveratrol

    DEFF Research Database (Denmark)

    Andishmand, Hashem; Mahnaz Tabibiazar; Mohammadifar, Mohammad Amin

    2017-01-01

    The aim of the present study was to develop chitosan-zinc-pectinate-polyethylene glycol (PEG) nanoparticles (NPs) for colon-targeted delivery of resveratrol. The effects of pectin:ZnCl2:chitosan (PZnC) % w/v, pH and ionic strength of media, and addition of PEG on the colloidal stability and release...

  2. Aptamer Recognition Induced Target-Bridged Strategy for Proteins Detection Based on Magnetic Chitosan and Silver/Chitosan Nanoparticles Using Surface-Enhanced Raman Spectroscopy.

    Science.gov (United States)

    He, Jincan; Li, Gongke; Hu, Yuling

    2015-11-03

    Poor selectivity and biocompability remain problems in applying surface-enhanced Raman spectroscopy (SERS) for direct detection of proteins due to similar spectra of most proteins and overlapping Raman bands in complex mixtures. To solve these problems, an aptamer recognition induced target-bridged strategy based on magnetic chitosan (MCS) and silver/chitosan nanoparticles (Ag@CS NPs) using SERS was developed for detection of protein benefiting from specific affinity of aptamers and biocompatibility of chitosan (CS). In this process, one aptamer (or antibody) modified MCS worked as capture probes through the affinity binding site of protein. The other aptamer modified Raman report molecules encapsulated Ag@CS NPs were used as SERS sensing probes based on the other binding site of protein. The sandwich complexes of aptamer (antibody)/protein/aptamer were separated easily with a magnet from biological samples, and the concentration of protein was indirectly reflected by the intensity variation of SERS signal of Raman report molecules. To explore the universality of the strategy, three different kinds of proteins including thrombin, platelet derived growth factor BB (PDGF BB) and immunoglobulin E (lgE) were investigated. The major advantages of this aptamer recognition induced target-bridged strategy are convenient operation with a magnet, stable signal expressing resulting from preventing loss of report molecules with the help of CS shell, and the avoidance of slow diffusion-limited kinetics problems occurring on a solid substrate. To demonstrate the feasibility of the proposed strategy, the method was applied to detection of PDGF BB in clinical samples. The limit of detection (LOD) of PDGF BB was estimated to be 3.2 pg/mL. The results obtained from human serum of healthy persons and cancer patients using the proposed strategy showed good agreement with that of the ELISA method but with wider linear range, more convenient operation, and lower cost. The proposed

  3. Chitosan-based multifunctional nanomedicines and theranostics for targeted therapy of cancer.

    Science.gov (United States)

    Fathi, Marziyeh; Majidi, Sima; Zangabad, Parham Sahandi; Barar, Jaleh; Erfan-Niya, Hamid; Omidi, Yadollah

    2018-05-30

    Nanotechnology as an emerging field has established inevitable impacts on nano-biomedicine and treatment of formidable diseases, inflammations, and malignancies. In this regard, substantial advances in the design of systems for delivery of therapeutic agents have emerged magnificent and innovative pathways in biomedical applications. Chitosan (CS) is derived via deacetylation of chitin as the second most abundant polysaccharide. Owing to the unique properties of CS (e.g., biocompatibility, biodegradability, bioactivity, mucoadhesion, cationic nature and functional groups), it is an excellent candidate for diverse biomedical and pharmaceutical applications such as drug/gene delivery, transplantation of encapsulated cells, tissue engineering, wound healing, antimicrobial purposes, etc. In this review, we will document, discuss, and provide some key insights toward design and application of miscellaneous nanoplatforms based on CS. The CS-based nanosystems (NSs) can be employed as advanced drug delivery systems (DDSs) in large part due to their remarkable physicochemical and biological characteristics. The abundant functional groups of CS allow the facile functionalization in order to engineer multifunctional NSs, which can simultaneously incorporate therapeutic agents, molecular targeting, and diagnostic/imaging capabilities in particular against malignancies. These multimodal NSs can be literally translated into clinical applications such as targeted diagnosis and therapy of cancer because they offer minimal systemic toxicity and maximal cytotoxicity against cancer cells and tumors. The recent developments in the CS-based NSs functionalized with targeting and imaging agents prove CS as a versatile polymer in targeted imaging and therapy. © 2018 Wiley Periodicals, Inc.

  4. Iontophoresis on minoxidil sulphate-loaded chitosan nanoparticles accelerates drug release, decreasing their targeting effect to hair follicles

    Directory of Open Access Journals (Sweden)

    Breno N. Matos

    Full Text Available The experiments described in this paper tested the hypothesis whether iontophoresis applied on a chitosan nanoparticle formulation could combine the enhanced drug accumulation into the follicular casts obtained using iontophoresis and the sustained drug release, reducing dermal exposure, provided by nanoparticles. Results showed that even though iontophoresis presented comparable minoxidil targeting potential to hair follicles than passive delivery of chitosan-nanoparticles (4.1 ± 0.9 and 5.3 ± 1.0 µg cm-2, respectively, it was less effective on preventing dermal exposure, since chitosan-nanoparticles presented a drug permeation in the receptor solution of 15.3 ± 4.3 µg cm-2 after 6 h of iontophoresis, while drug amounts from passive nanoparticle delivery were not detected. Drug release experiments showed particles were not able to sustain the drug release under the influence of a potential gradient. In conclusion, the application of MXS-loaded chitosan nanoparticles remains the best way to target MXS to the hair follicles while preventing dermal exposure.

  5. Preparation and characterization of gadolinium-loaded PLGA particles surface modified with RGDS for the detection of thrombus

    Directory of Open Access Journals (Sweden)

    Zhang Y

    2013-10-01

    Full Text Available Yu Zhang,1 Jun Zhou,1 Dajing Guo,1 Meng Ao,2 Yuanyi Zheng,2 Zhigang Wang21Department of Radiology, the Second Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of China; 2Institute of Ultrasound Imaging, Department of Ultrasound, the Second Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of ChinaAbstract: Thrombotic disease is a leading cause of death and disability worldwide. The development of magnetic resonance molecular imaging provides potential promise for early disease diagnosis. In this study, we explore the preparation and characterization of gadolinium (Gd-loaded poly (lactic-co-glycolic acid (PLGA particles surface modified with the Arg-Gly-Asp-Ser (RGDS peptide for the detection of thrombus. PLGA was employed as the carrier-delivery system, and a double emulsion solvent-evaporation method (water in oil in water was used to prepare PLGA particles encapsulating the magnetic resonance contrast agent Gd diethylenetriaminepentaacetic acid (DTPA. To synthesize the Gd-PLGA/chitosan (CS-RGDS particles, carbodiimide-mediated amide bond formation was used to graft the RGDS peptide to CS to form a CS-RGDS film that coated the surface of the PLGA particles. Blank PLGA, Gd-PLGA, and Gd-PLGA/CS particles were fabricated using the same water in oil in water method. Our results indicated that the RGDS peptide successfully coated the surface of the Gd-PLGA/CS-RGDS particles. The particles had a regular shape, smooth surface, relatively uniform size, and did not aggregate. The high electron density of the Gd-loaded particles and a translucent film around the particles coated with the CS and CS-RGDS films could be observed by transmission electron microscopy. In vitro experiments demonstrated that the Gd-PLGA/CS-RGDS particles could target thrombi and could be imaged using a clinical magnetic resonance scanner. Compared with the Gd-DTPA solution, the longitudinal relaxation time of

  6. Asialoglycoprotein-receptor-targeted hepatocyte imaging using {sup 99m}Tc galactosylated chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun-Mi [Department of Nuclear Medicine, Research Institute of Clinical Medicine, Chonbuk National University School of Medicine, Jeonju, Jeonbuk (Korea, Republic of); Jeong, Hwan-Jeong [Department of Nuclear Medicine, Research Institute of Clinical Medicine, Chonbuk National University School of Medicine, Jeonju, Jeonbuk (Korea, Republic of)]. E-mail: jayjeong@chonbuk.ac.kr; Kim, Se-Lim [Department of Nuclear Medicine, Research Institute of Clinical Medicine, Chonbuk National University School of Medicine, Jeonju, Jeonbuk (Korea, Republic of); Sohn, Myung-Hee [Department of Nuclear Medicine, Research Institute of Clinical Medicine, Chonbuk National University School of Medicine, Jeonju, Jeonbuk (Korea, Republic of); Nah, Jae-Woon [Division of Applied Materials Engineering, Department of Polymer Science and Engineering, Sunchon National University, Sunchon, Jeonnam (Korea, Republic of); Bom, Hee-Seung [Department of Nuclear Medicine, Chonnam National University School of Medicine, Gwangju (Korea, Republic of); Park, In-Kyu [School of Agricultural Biotechnology, Seoul National University, Seoul (Korea, Republic of); Cho, Chong-Su [School of Agricultural Biotechnology, Seoul National University, Seoul (Korea, Republic of)

    2006-05-15

    This study investigated the usefulness of {sup 99m}Tc hydrazinonicotinamide-galactosylated chitosan (HGC) in hepatocyte imaging. HGC was obtained by coupling the galactose moiety of both lactobionic acid and succinimidyl 6-hydrazinonicotinate hydrochloride (succinimidyl HYNIC). The coupled product was then radiolabeled with {sup 99m}Tc using stannous chloride and tricine as reducing agent and coligand, respectively. Labeling efficiency was >90% both in room temperature and in serum up to 24 h after injection. The hepatic uptake properties of {sup 99m}Tc HGC were studied in Balb/C mice. {sup 99m}Tc HGC and {sup 99m}Tc hydrazinonicotinamide chitosan (HC) were intravenously injected into mice, with receptor binding identified by coinjection with 9 and 14 mg of free galactose. Images were acquired with a {gamma}-camera. After injection via the tail vein of the mice, {sup 99m}Tc HGC showed high selectivity for the liver, while {sup 99m}Tc HC without a galactose group showed low liver uptake. In addition, the hepatic uptake of {sup 99m}Tc HGC was blocked by coinjection of free galactose. Tissue distribution was determined at three different times (10, 60 and 120 min). The liver accumulated 13.16{+-}2.72%, 16.11{+-}5.70% and 16.55{+-}2.28% of the injected dose per gram at 10, 60 and 120 min after injection, respectively. {sup 99m}Tc HGC showed specific and rapid targeting of hepatocytes. It is a promising receptor-specific radiopharmaceutical with potential applications in liver imaging for the evaluation of hepatocytic function.

  7. TNYL peptide functional chitosan-g-stearate conjugate micelles for tumor specific targeting

    Directory of Open Access Journals (Sweden)

    Chen FY

    2014-09-01

    Full Text Available Feng-Ying Chen,1 Jing-Jing Yan,1 Han-Xi Yi,2 Fu-Qiang Hu,2 Yong-Zhong Du,2 Hong Yuan,2 Jian You,2 Meng-Dan Zhao1 1Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, People’s Republic of China; 2College of Pharmaceutical Science, Zhejiang University, Hangzhou, People’s Republic of China Abstract: Nowadays, a real challenge in cancer therapy is to design drug delivery systems that can achieve high concentrations of drugs at the target site for improved therapeutic effect with reduced side effects. In this research, we designed and synthesized a homing peptide-(TNYLFSPNGPIA, TNYL modified chitosan-g-stearate (CS polymer micelle (named T-CS for targeting delivery. The peptide displayed specific binding affinity to EphB4 which is a member of the Eph family of receptor tyrosine protein kinases. The amphiphilic polymer T-CS can gather into micelles by themselves in an aqueous environment with a low critical micelle concentration value (91.2 µg/L and nano-scaled size (82.1±2.8 nm. The drug encapsulation efficiency reached 86.43% after loading the hydrophobic drug doxorubicin (DOX. The cytotoxicity of T-CS/DOX against SKOV3 cells was enhanced by approximately 2.3-fold when compared with CS/DOX. The quantitative and qualitative analysis for cellular uptake indicated that TNYL modification can markedly increase cellular internalization in the EphB4-overexpressing SKOV3 cell line, especially with a short incubation time. It is interesting that relatively higher uptake of the T-CS/DOX micelles by SKOV3 cells (positive-EphB4 than A549 cells (negative-EphB4 was observed when the two cells were co-incubated. Furthermore, in vivo distribution experiment using a bilateral-tumor model showed that there was more fluorescence accumulation in the SKOV3 tumor than in the A549 tumor over the whole experiment. These results suggest that TNYL-modified CS micelles may be promising drug carriers as targeting therapy for the EphB4-overexpressing

  8. Magnetic Nanoparticles of Chitosan for Targeted Delivery System of Plasmids to the Lungs

    International Nuclear Information System (INIS)

    Baez, C.A.A.; Cruz, I.E.L.; Padilla, M.C.R.; Gonzalez, J.M.A.

    2014-01-01

    One of the major problems of gene therapy is the efficient, specific, and targeted delivery as well as the safety of the materials used in such systems. The specific targeted delivery of genes to the lung offers the possibility to treat a variety of specific diseases. We developed chitosan nanoparticles with the plasmid pCEM-Luc, which contains a promoter activated by magnetic field. Nanoparticles of 200-250 nm obtained by ionic gelation with a 99% retention rate were transfected in B16F10 cells and in vivo in the lungs of Balb/c mice by intratracheal administration. We observed that an external magnetic field increased the expression of the luciferase reporter gene in B16F10 cells transfected with magnetic nanoparticles and in homogenized lungs of mice which determined differences in levels of expression between different regions of the lungs (apical or distal and left or right). The highest levels of luciferase activity were observed in the apical left region. The magnetic nanoparticles prove an efficient delivery system to in vitro transfection of cells and lung tissue.

  9. High molecular weight chitosan derivative polymeric micelles encapsulating superparamagnetic iron oxide for tumor-targeted magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Xiao Y

    2015-02-01

    Full Text Available Yunbin Xiao,1,* Zuan Tao Lin,2,* Yanmei Chen,1 He Wang,1 Ya Li Deng,2 D Elizabeth Le,3 Jianguo Bin,1 Meiyu Li,1 Yulin Liao,1 Yili Liu,1 Gangbiao Jiang,2 Jianping Bin1 1State Key Laboratory of Organ Failure Research, Division of Cardiology, Nanfang Hospital, Southern Medical University, Guangzhou, People’s Republic of China; 2Department of Pharmaceutical Engineering, South China Agricultural University, Guangzhou, People’s Republic of China; 3Cardiovascular Division, Oregon Health and Science University, Portland, OR, USA *These authors contributed equally to this work Abstract: Magnetic resonance imaging (MRI contrast agents based on chitosan derivatives have great potential for diagnosing diseases. However, stable tumor-targeted MRI contrast agents using micelles prepared from high molecular weight chitosan derivatives are seldom reported. In this study, we developed a novel tumor-targeted MRI vehicle via superparamagnetic iron oxide nanoparticles (SPIONs encapsulated in self-aggregating polymeric folate-conjugated N-palmitoyl chitosan (FAPLCS micelles. The tumor-targeting ability of FAPLCS/SPIONs was demonstrated in vitro and in vivo. The results of dynamic light scattering experiments showed that the micelles had a relatively narrow size distribution (136.60±3.90 nm and excellent stability. FAPLCS/SPIONs showed low cytotoxicity and excellent biocompatibility in cellular toxicity tests. Both in vitro and in vivo studies demonstrated that FAPLCS/SPIONs bound specifically to folate receptor-positive HeLa cells, and that FAPLCS/SPIONs accumulated predominantly in established HeLa-derived tumors in mice. The signal intensities of T2-weighted images in established HeLa-derived tumors were reduced dramatically after intravenous micelle administration. Our study indicates that FAPLCS/SPION micelles can potentially serve as safe and effective MRI contrast agents for detecting tumors that overexpress folate receptors. Keywords: superparamagnetic

  10. Extraction and encapsulation of prodigiosin in chitosan microspheres for targeted drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Dozie-Nwachukwu, S.O. [Department of Materials Science and Engineering, African University of Science and Technology (AUST) Abuja, Federal Capital Territory (Nigeria); Biotechnology and Genetic Engineering Advanced Laboratory, Sheda Science and Technology Complex (SHESTCO), P.M.B 186, Garki, Abuja, Federal Capital Territory (Nigeria); Danyuo, Y. [Department of Materials Science and Engineering, African University of Science and Technology (AUST) Abuja, Federal Capital Territory (Nigeria); Department of Materials Science and Engineering, Kwara State University, Malete (Nigeria); Obayemi, J.D. [Department of Materials Science and Engineering, African University of Science and Technology (AUST) Abuja, Federal Capital Territory (Nigeria); Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States); Odusanya, O.S. [Department of Materials Science and Engineering, African University of Science and Technology (AUST) Abuja, Federal Capital Territory (Nigeria); Biotechnology and Genetic Engineering Advanced Laboratory, Sheda Science and Technology Complex (SHESTCO), P.M.B 186, Garki, Abuja, Federal Capital Territory (Nigeria); Malatesta, K. [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States); Soboyejo, W.O., E-mail: soboyejo@princeton.edu [Department of Materials Science and Engineering, African University of Science and Technology (AUST) Abuja, Federal Capital Territory (Nigeria); Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States); Princeton Institute of Science and Technology of Materials (PRISM), Bowen Hall, 70 Prospect Street, Princeton, NJ 08544 (United States)

    2017-02-01

    The encapsulation of drugs in polymeric materials has brought opportunities to the targeted delivery of chemotherapeutic agents. These polymeric delivery systems are capable of maximizing the therapeutic activity, as well as reducing the side effects of anti-cancer agents. Prodigiosin, a secondary metabolite extracted from the bacteria, Serratia marcescens, exhibits anti-cancer properties. Prodigiosin-loaded chitosan microspheres were prepared via water-in-oil (w/o) emulsion technique, using glutaraldehyde as a cross-linker. The morphologies of the microspheres were studied using scanning electron microscopy. The average sizes of the microspheres were between 40 μm and 60 μm, while the percentage yields ranged from 42 ± 2% to 55.5 ± 3%. The resulting encapsulation efficiencies were between 66.7 ± 3% and 90 ± 4%. The in-vitro drug release from the microspheres was characterized by zeroth order, first order and Higuchi and Korsmeyer-Peppas models. - Highlights: • Prodigiosin of ~ 92.8% purity was extracted from locally isolated Serratia marcescens. • This approach reduces the cost and ensure availability of drugs for cancer treatment. • High encapsulation efficiency which increased with increasing drug:polymer ratio • The percentage yield was generally poor due to the recovery process. • Prodigiosin greatly reduced the viability of the breast cancer cell line (MDA-MB-231).

  11. Extraction and encapsulation of prodigiosin in chitosan microspheres for targeted drug delivery

    International Nuclear Information System (INIS)

    Dozie-Nwachukwu, S.O.; Danyuo, Y.; Obayemi, J.D.; Odusanya, O.S.; Malatesta, K.; Soboyejo, W.O.

    2017-01-01

    The encapsulation of drugs in polymeric materials has brought opportunities to the targeted delivery of chemotherapeutic agents. These polymeric delivery systems are capable of maximizing the therapeutic activity, as well as reducing the side effects of anti-cancer agents. Prodigiosin, a secondary metabolite extracted from the bacteria, Serratia marcescens, exhibits anti-cancer properties. Prodigiosin-loaded chitosan microspheres were prepared via water-in-oil (w/o) emulsion technique, using glutaraldehyde as a cross-linker. The morphologies of the microspheres were studied using scanning electron microscopy. The average sizes of the microspheres were between 40 μm and 60 μm, while the percentage yields ranged from 42 ± 2% to 55.5 ± 3%. The resulting encapsulation efficiencies were between 66.7 ± 3% and 90 ± 4%. The in-vitro drug release from the microspheres was characterized by zeroth order, first order and Higuchi and Korsmeyer-Peppas models. - Highlights: • Prodigiosin of ~ 92.8% purity was extracted from locally isolated Serratia marcescens. • This approach reduces the cost and ensure availability of drugs for cancer treatment. • High encapsulation efficiency which increased with increasing drug:polymer ratio • The percentage yield was generally poor due to the recovery process. • Prodigiosin greatly reduced the viability of the breast cancer cell line (MDA-MB-231).

  12. PREPARATION AND CHARACTERIZATION OF CHITOSAN TABLETS OF ACECLOFENAC FOR COLON TARGETED DRUG DELIVERY

    OpenAIRE

    UMA DEVI,THIRUGANESH, SURESH

    2013-01-01

    The present study objective was to develop novel colon specific drug delivery systems for aceclofenac using chitosan as a microbially degradable polymeric carrier and to coat the optimized batches with a pH dependent polymeric coating solution containing Eudragit L 100 and S 100 (1:4). Tablets containing four proportions of chitosan were prepared. The tablets were evaluated for physicochemical properties, drug content, dissolution, water uptake & erosion characteristics, in vitro drug rel...

  13. Targeted delivery of doxorubicin-utilizing chitosan nanoparticles surface-functionalized with anti-Her2 trastuzumab

    Directory of Open Access Journals (Sweden)

    Yousefpour P

    2011-09-01

    Full Text Available Parisa Yousefpour1, Fatemeh Atyabi2, Ebrahim Vasheghani-Farahani3, Ali-Akbar Mousavi Movahedi1, Rassoul Dinarvand21Department of Biotechnology, Faculty of Science, University of Tehran, 2Nanotechnology Research Centre, Faculty of Pharmacy, Tehran University of Medical Sciences, 3Biotechnology Group, Department of Chemical Engineering, Faculty of Engineering, Tarbiat Modares University, Tehran, IranBackground: Targeting drugs to their sites of action to overcome the systemic side effects associated with most antineoplastic agents is still a major challenge in pharmaceutical research. In this study, the monoclonal antibody, trastuzumab, was used as a targeting agent in nanoparticles carrying the antitumor drug, doxorubicin, specifically to its site of action.Methods: Chitosan-doxorubicin conjugation was carried out using succinic anhydride as a crosslinker. Trastuzumab was conjugated to self-assembled chitosan-doxorubin conjugate (CS-DOX nanoparticles (particle size, 200 nm via thiolation of lysine residues and subsequent linking of the resulted thiols to chitosan. Conjugation was confirmed by gel permeation chromatography, differential scanning calorimetry, Fourier transform infrared spectroscopy, and 1H nuclear magnetic resonance spectroscopy studies. Dynamic light scattering, transmission electron microscopy, and zeta potential determination were used to characterize the nanoparticles.Results: CS-DOX conjugated nanoparticles had a spherical shape and smooth surface with a narrow size distribution and core-shell structure. Increasing the ratio of doxorubicin to chitosan in the conjugation reaction gave rise to a higher doxorubicin content but lower conjugation efficiency. Trastuzumab-decorated nanoparticles (CS-DOX-mAb contained 47 µg/mg doxorubicin and 33.5 µg/mg trastuzumab. Binding of trastuzumab to the nanoparticles was further probed thermodynamically by isothermal titration calorimetry. Fluorescence microscopy demonstrated enhanced and

  14. Targeted DNA delivery to cancer cells using a biotinylated chitosan carrier.

    Science.gov (United States)

    Darvishi, Mohammad H; Nomani, Alireza; Hashemzadeh, Hadi; Amini, Mohsen; Shokrgozar, Mohammad A; Dinarvand, Rassoul

    2017-05-01

    A novel biotinylated chitosan-graft-polyethyleneimine (Bio-Chi-g-PEI) copolymer was synthesized and evaluated as a nonviral gene delivery carrier for improvement of the transfection efficiency, endosomal escape, and targeted gene delivery of a plasmid encoding green fluorescent protein N1 (pEGFP-N1) into two different biotin-overexpressing cell lines including HeLa and OVCAR-3 cells. The structure of the obtained copolymers was confirmed by 1 H nuclear magnetic resonance ( 1 H NMR) and Fourier transform infrared spectroscopy. Physicochemical properties of the Bio-Chi-g-PEI/plasmid DNA (pDNA) complexes such as complex stability, size, zeta potential, and their morphology were investigated at various weight ratios of copolymer to pDNA. Bio-Chi-g-PEI copolymers could effectively condense pDNA into small particles with average diameters less than 164 nm and the zeta potential of +34.8 mV at the N/P ratio of 40/1. As revealed by flow cytometry, Bio-Chi-g-PEI/pDNA complexes had lower cytotoxicity than that of PEI 25 kDa/pDNA complexes in both cell lines. In vitro experiments revealed that the Bio-Chi-gPEI/pDNA complexes not only had much lower cytotoxicity, but also displayed higher transfection efficiency than that of PEI 25kDa/pDNA complexes. High percentage of cancer cells was successfully transfected by Bio-Chi-g-PEI/pDNA and properly expressed GFP protein. This study indicates that this copolymer complex can be a promising gene delivery carrier. © 2016 International Union of Biochemistry and Molecular Biology, Inc.

  15. Disruption of Aedes aegypti olfactory system development through chitosan/siRNA nanoparticle targeting of semaphorin-1a.

    Directory of Open Access Journals (Sweden)

    Keshava Mysore

    Full Text Available Despite the devastating impact of mosquito-borne illnesses on human health, surprisingly little is known about mosquito developmental biology, including development of the olfactory system, a tissue of vector importance. Analysis of mosquito olfactory developmental genetics has been hindered by a lack of means to target specific genes during the development of this sensory system. In this investigation, chitosan/siRNA nanoparticles were used to target semaphorin-1a (sema1a during olfactory system development in the dengue and yellow fever vector mosquito Aedes aegypti. Immunohistochemical analyses and anterograde tracing of antennal sensory neurons, which were used to track the progression of olfactory development in this species, revealed antennal lobe defects in sema1a knockdown fourth instar larvae. These findings, which correlated with a larval odorant tracking behavioral phenotype, identified previously unreported roles for Sema1a in the developing insect larval olfactory system. Analysis of sema1a knockdown pupae also revealed a number of olfactory phenotypes, including olfactory receptor neuron targeting and projection neuron defects coincident with a collapse in the structure and shape of the antennal lobe and individual glomeruli. This study, which is to our knowledge the first functional genetic analysis of insect olfactory development outside of D. melanogaster, identified critical roles for Sema1a during Ae. aegypti larval and pupal olfactory development and advocates the use of chitosan/siRNA nanoparticles as an effective means of targeting genes during post-embryonic Ae. aegypti development. Use of siRNA nanoparticle methodology to understand sensory developmental genetics in mosquitoes will provide insight into the evolutionary conservation and divergence of key developmental genes which could be exploited in the development of both common and species-specific means for intervention.

  16. Multicomponent, peptide-targeted glycol chitosan nanoparticles containing ferrimagnetic iron oxide nanocubes for bladder cancer multimodal imaging

    Directory of Open Access Journals (Sweden)

    Key J

    2016-08-01

    , by using cyanine 5.5 fluorescence molecules. We changed the physicochemical properties of glycol chitosan nanoparticles by conjugating bladder cancer-targeting peptides and loading many ferrimagnetic iron oxide NCs per glycol chitosan nanoparticle to improve MRI contrast. The 22 nm ferrimagnetic NCs were stabilized in physiological conditions by encapsulating them within modified chitosan nanoparticles. The multimodal nanoparticles were compared with in vivo MRI and near infrared fluorescent systems. We demonstrated significant and important changes in the biodistribution and tumor accumulation of nanoparticles with different physicochemical properties. Finally, we demonstrated that multimodal nanoparticles specifically visualize small tumors and show minimal accumulation in other organs. This work reveals the importance of finely modulating physicochemical properties in designing multimodal nanoparticles for bladder cancer imaging.Keywords: MRI, NIRF, multimodal imaging, chitosan, iron oxide, bladder cancer

  17. Folate Receptor-targeted Bioflavonoid Genistein-loaded Chitosan Nanoparticles for Enhanced Anticancer Effect in Cervical Cancers

    Science.gov (United States)

    Cai, Limei; Yu, Rufen; Hao, Xi; Ding, Xiangcui

    2017-08-01

    In this study, novel folic acid-conjugated chitosan nanoparticle was formulated for specific delivery of bioflavonoid, Genistein (GEN), to the cervical cancer cells. The prepared GEN-loaded chitosan nanoparticles (GCN) and folic acid-conjugated GCN (FGCN) showed smaller size with a controlled drug release profile. FGCN exhibited enhanced internalization potential in HeLa cells than that of GCN. The specific internalization of FGCN was mainly due to the affinity of folic acid (FA) with FRs-α which is present in large numbers in HeLa cells. The results revealed that FGCN has a specific affinity towards HeLa cells that will contribute to the better treatment. Folic acid-tagged nanoformulations exhibited a superior cytotoxic effect compared to that of non-targeted formulations. Consistently, IC50 value of GEN decreased from 33.8 to 14.6 μg/ml when treated with FGCN after 24 h incubation. The apoptosis studies indicated that the FGCN nanoparticles were then either GCN or free GEN in terms of anticancer activity. Overall, results revealed that folate conjugation to the delivery system might have great effect on the survival of cervical cancers that will be beneficial for overall cancer treatment.

  18. Glycol chitosan

    DEFF Research Database (Denmark)

    Danielsen, E Thomas; Danielsen, E Michael

    2017-01-01

    Chitosan is a polycationic polysaccharide consisting of β-(1-4)-linked glucosamine units and due to its mucoadhesive properties, chemical derivatives of chitosan are potential candidates as enhancers for transmucosal drug delivery. Recently, glycol chitosan (GC), a soluble derivative of chitosan...

  19. Chitosan encapsulation of essential oil "cocktails" with well-defined binary Zn(II)-Schiff base species targeting antibacterial medicinal nanotechnology.

    Science.gov (United States)

    Halevas, Eleftherios; Nday, Christiane M; Chatzigeorgiou, Evanthia; Varsamis, Vasileios; Eleftheriadou, Despoina; Jackson, Graham E; Litsardakis, Georgios; Lazari, Diamanto; Ypsilantis, Konstantinos; Salifoglou, Athanasios

    2017-11-01

    The advent of biodegradable nanomaterials with enhanced antibacterial activity stands as a challenge to the global research community. In an attempt to pursue the development of novel antibacterial medicinal nanotechnology, we herein a) synthesized ionic-gelated chitosan nanoparticles, b) compared and evaluated the antibacterial activity of essential oils extracted from nine different herbs (Greek origin) and their combinations with a well-defined antibacterial Zn(II)-Schiff base compound, and c) encapsulated the most effective hybrid combination of Zn(II)-essential oils inside the chitosan matrix, thereby targeting well-formulated nanoparticles of distinct biological impact. The empty and loaded chitosan nanoparticles were physicochemically characterized by FT-IR, Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), with the entrapment and drug release studies being conducted through UV-Visible and atomic absorption techniques. The antimicrobial properties of the novel hybrid materials were demonstrated against Gram positive (S. aureus, B. subtilis, and B. cereus) and Gram negative (E. coli and X. campestris) bacteria using modified agar diffusion methods. The collective physicochemical profile of the hybrid Zn(II)-essential oil cocktails, formulated so as to achieve optimal activity when loaded to chitosan nanoparticles, signifies the importance of design in the development of efficient nanomedicinal pharmaceuticals a) based on both natural products and biogenic metal ionic cofactors, and b) targeting bacterial infections and drug resistance. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. MHI-148 Cyanine Dye Conjugated Chitosan Nanomicelle with NIR Light-Trigger Release Property as Cancer Targeting Theranostic Agent.

    Science.gov (United States)

    Thomas, Reju George; Moon, Myeong Ju; Surendran, Suchithra Poilil; Park, Hyeong Ju; Park, In-Kyu; Lee, Byeong-Il; Jeong, Yong Yeon

    2018-02-15

    Paclitaxel (PTX) loaded hydrophobically modified glycol chitosan (HGC) micelle is biocompatible in nature, but it requires cancer targeting ability and stimuli release property for better efficiency. To improve tumor retention and drug release characteristic of HGC-PTX nanomicelles, we conjugated cancer targeting heptamethine dye, MHI-148, which acts as an optical imaging agent, targeting moiety and also trigger on-demand drug release on application of NIR 808 nm laser. The amine group of glycol chitosan modified with hydrophobic 5β-cholanic acid and the carboxyl group of MHI-148 were bonded by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide chemistry. Paclitaxel was loaded to MHI-HGC nanomicelle by an oil-in-water emulsion method, thereby forming MHI-HGC-PTX. Comparison of near infrared (NIR) dyes, MHI-148, and Flamma-774 conjugated to HGC showed higher accumulation for MHI-HGC in 4T1 tumor and 4T1 tumor spheroid. In vitro studies showed high accumulation of MHI-HGC-PTX in 4T1 and SCC7 cancer cell lines compared to NIH3T3 cell line. In vivo fluorescence imaging of the 4T1 and SCC7 tumor showed peak accumulation of MHI-HGC-PTX at day 1 and elimination from the body at day 6. MHI-HGC-PTX showed good photothermal heating ability (50.3 °C), even at a low concentration of 33 μg/ml in 1 W/cm 2 808 nm laser at 1 min time point. Tumor reduction studies in BALB/c nude mice with SCC7 tumor showed marked reduction in MHI-HGC-PTX in the PTT group combined with photothermal therapy compared to MHI-HGC-PTX in the group without PTT. MHI-HGC-PTX is a cancer theranostic agent with cancer targeting and optical imaging capability. Our studies also showed that it has cancer targeting property independent of tumor type and tumor reduction property by combined photothermal and chemotherapeutic effects.

  1. Chitosan-Graft-Polyethylenimine/DNA Nanoparticles as Novel Non-Viral Gene Delivery Vectors Targeting Osteoarthritis

    Science.gov (United States)

    Lv, Lulu; Zhao, Huiqing

    2014-01-01

    The development of safe and efficient gene carriers is the key to the clinical success of gene therapy. The present study was designed to develop and evaluate the chitosan-graft-polyethylenimine (CP)/DNA nanoparticles as novel non-viral gene vectors for gene therapy of osteoarthritis. The CP/DNA nanoparticles were produced through a complex coacervation of the cationic polymers with pEGFP after grafting chitosan (CS) with a low molecular weight (Mw) PEI (Mw = 1.8 kDa). Particle size and zeta potential were related to the weight ratio of CP:DNA, where decreases in nanoparticle size and increases in surface charge were observed as CP content increased. The buffering capacity of CP was significantly greater than that of CS. The transfection efficiency of CP/DNA nanoparticles was similar with that of the Lipofectamine™ 2000, and significantly higher than that of CS/DNA and PEI (25 kDa)/DNA nanoparticles. The transfection efficiency of the CP/DNA nanoparticles was dependent on the weight ratio of CP:DNA (w/w). The average cell viability after the treatment with CP/DNA nanoparticles was over 90% in both chondrocytes and synoviocytes, which was much higher than that of PEI (25 kDa)/DNA nanoparticles. The CP copolymers efficiently carried the pDNA inside chondrocytes and synoviocytes, and the pDNA was detected entering into nucleus. These results suggest that CP/DNA nanoparticles with improved transfection efficiency and low cytotoxicity might be a safe and efficient non-viral vector for gene delivery to both chondrocytes and synoviocytes. PMID:24392152

  2. Development and evaluation of thymoquinone-encapsulated chitosan nanoparticles for nose-to-brain targeting: a pharmacoscintigraphic study

    Directory of Open Access Journals (Sweden)

    Alam S

    2012-11-01

    -loaded nanoparticles (TQ-NP1 proved more effective in brain targeting compared to intravenous and intranasal TQ solution. The high drug-targeting potential and efficiency demonstrates the significant role of the mucoadhesive properties of TQ-NP1.Keywords: thymoquinone, chitosan, nanoparticles, nose-to-brain targeting, gamma scintigraphy

  3. Folate-decorated chitosan/doxorubicin poly(butyl)cyanoacrylate nanoparticles for tumor-targeted drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Duan Jinghua [Xiangya Hospital, Central South University, Hepatobiliary and Enteric Surgery Research Center (China); Liu Mujun [Central South University, School of Biological Science and Technology (China); Zhang Yangde; Zhao Jinfeng; Pan Yifeng [Xiangya Hospital, Central South University, Hepatobiliary and Enteric Surgery Research Center (China); Yang Xiyun, E-mail: bax_2007@126.com [Central South University, School of Metallurgical Science and Engineering (China)

    2012-03-15

    A novel chitosan coated poly(butyl cyanoacrylate) (PBCA) nanoparticles loaded doxorubicin (DOX) were synthesized and then conjugated with folic acid to produce a folate-targeted drug carrier for tumor-specific drug delivery. Prepared nanoparticles were surface modified by folate for targeting cancer cells, which is confirmed by FTIR spectroscopy and characterized for shape, size, and zeta potential measurements. The size and zeta potential of prepared DOX-PBCA nanoparticles (DOX-PBCA NPs) were almost 174 {+-} 8.23 nm and +23.14 {+-} 4.25 mV, respectively with 46.8 {+-} 3.32% encapsulation capacity. The transmission electron microscopy study revealed that preparation allowed the formation of spherical nanometric and homogeneous. Fluorescent microscopy imaging and flow cytometry analysis revealed that DOX-PBCA NPs were endocytosed into MCF-7 cells through the interaction with overexpressed folate receptors on the surface of the cancer cells. The results demonstrate that folate-conjugated DOX-PBCA NPs drug delivery system could provide increased therapeutic benefit by delivering the encapsulated drug to the folate receptor positive cancer cells.

  4. Paclitaxel loaded magnetic nanocomposites with folate modified chitosan/carboxymethyl surface; a vehicle for imaging and targeted drug delivery.

    Science.gov (United States)

    Bano, Shazia; Afzal, Muhammad; Waraich, Mustansar Mahmood; Alamgir, Khalid; Nazir, Samina

    2016-11-20

    In this study, Paclitaxel (PTX) containing, bovine serum albumin (BSA) nanoparticles were fabricated via a simple approach. Folic acid (FA) was conjugated to chitosan (CS)/carboxymethyl cellulose (CMC) through an esterification reaction to produce BSA-CS-FA or BSA-CMC-FA conjugates. NiFe 2 O 4 noncore (NFs) and PTX were loaded through a heat treatment and by a diffusion process. NFs-BSA-CS and NFs-BSA-CMC-FA with size of about 80nm, showed superior transversal R 2 relaxation rate of 349 (mM) -1 s -1 along with folate receptor-targeted and magnetically directed functions. NFs-BSA-CS-FA or NFs-BSA-CS-FA were found stable and biocompatible. Application of an external magnetic field effectively enhanced the PTX release from PTX-NFs-BSA-CS-FA or PTX-NFs-BSA-CS-FA and hence tumor inhibition rate. This study validate that NFs-BSA-CS-FA or NFs-BSA-CMC-FA and PTX-NFs-BSA-CS-FA or PTX-NFs-BSA-CS-FA are suitable systems for tumor diagnosis and therapy. Copyright © 2016. Published by Elsevier B.V.

  5. Mannosylated Chitosan Nanoparticles Based Macrophage-Targeting Gene Delivery System Enhanced Cellular Uptake and Improved Transfection Efficiency.

    Science.gov (United States)

    Peng, Yixing; Yao, Wenjun; Wang, Bo; Zong, Li

    2015-04-01

    Gene transfer mediated by mannosylated chitosan (MCS) is a safe and promising approach for gene and vaccine delivery. MCS nanoparticles based gene delivery system showed high in vivo delivery efficiency and elicited strong immune responses in mice. However, little knowledge about the cell binding, transfection efficiency and intracellular trafficking of MCS nanoparticles had been acquired. In this study, using gastrin-releasing peptide as a model plasmid (pGRP), the binding of MCS/pGRP nanoparticles to macrophages and the intracellular trafficking of MCS/pGRP nanoparticles in macrophages were investigated. MCS-mediated transfection efficiency in macrophages was also evaluated using pGL-3 as a reporter gene. The results showed that the binding and transfection efficiency of MCS nanoparticles in macrophages was higher than that of CS, which was attributed to the interaction between mannose ligands in MCS and mannose receptors on the surface of macrophages. Observation with a confocal laser scanning microscope indicated the cellular uptake of MCS/pGRP nanoparticles were more than that of CS/pGRP nanoparticles in macrophages. MCS/pGRP nanoparticles were taken up by macrophages and most of them were entrapped in endosomal/lysosomal compartments. After the nanoparticles escaping from endosomal/lysosomal compartments, naked pGRP entered the nucleus, and a few MCS might enter the nucleus in terms of nanoparticles. Overall, MCS has the potential to be an excellent macrophage-targeting gene delivery carrier.

  6. Cytocompatible chitosan-graft-mPEG-based 5-fluorouracil-loaded polymeric nanoparticles for tumor-targeted drug delivery.

    Science.gov (United States)

    Antoniraj, M Gover; Ayyavu, Mahesh; Henry, Linda Jeeva Kumari; Nageshwar Rao, Goutham; Natesan, Subramanian; Sundar, D Sathish; Kandasamy, Ruckmani

    2018-03-01

    Biodegradable materials like chitosan (CH) and methoxy polyethylene glycol (mPEG) are widely being used as drug delivery carriers for various therapeutic applications. In this study, copolymer (CH-g-mPEG) of CH and carboxylic acid terminated mPEG was synthesized by carbodiimide-mediated acid amine reaction. The resultant hydrophilic copolymer was characterized by Fourier transform infrared spectroscopy and 1 H NMR studies, revealing its relevant functional bands and proton peaks, respectively. Blank polymeric nanoparticles (B-PNPs) and 5-fluorouracil loaded polymeric nanoparticles (5-FU-PNPs) were formulated by ionic gelation method. Furthermore, folic acid functionalized FA-PNPs and FA-5-FU-PNPs were prepared for folate receptor-targeted drug delivery. FA-5-FU-PNPs were characterized by particle size, zeta potential, and in vitro drug release studies, resulting in 197.7 nm, +29.9 mv, and sustained drug release of 88% in 24 h, respectively. Cytotoxicity studies were performed for FA-PNPs and FA-5-FU-PNPs in MCF-7 cell line, which exhibited a cell viability of 80 and 41%, respectively. In vitro internalization studies were carried out for 5-FU-PNPs and FA-5-FU-PNPs which demonstrated increased cellular uptake of FA-5-FU-PNPs by receptor-mediated transport. Significant (p drug delivery, thereby influencing better therapeutic effect.

  7. Fabrication of nano-mosquitocides using chitosan from crab shells: Impact on non-target organisms in the aquatic environment.

    Science.gov (United States)

    Murugan, Kadarkarai; Anitha, Jaganathan; Dinesh, Devakumar; Suresh, Udaiyan; Rajaganesh, Rajapandian; Chandramohan, Balamurugan; Subramaniam, Jayapal; Paulpandi, Manickam; Vadivalagan, Chitravel; Amuthavalli, Pandiyan; Wang, Lan; Hwang, Jiang-Shiou; Wei, Hui; Alsalhi, Mohamad Saleh; Devanesan, Sandhanasamy; Kumar, Suresh; Pugazhendy, Kannaiyan; Higuchi, Akon; Nicoletti, Marcello; Benelli, Giovanni

    2016-10-01

    Mosquitoes are arthropods of huge medical and veterinary relevance, since they vector pathogens and parasites of public health importance, including malaria, dengue and Zika virus. Currently, nanotechnology is considered a potential eco-friendly approach in mosquito control research. We proposed a novel method of biofabrication of silver nanoparticles (AgNP) using chitosan (Ch) from crab shells. Ch-AgNP nanocomposite was characterized by UV-vis spectroscopy, FTIR, SEM, EDX and XRD. Ch-AgNP were tested against larvae and pupae of the malaria vector Anopheles stephensi obtaining LC50 ranging from 3.18 ppm (I) to 6.54 ppm (pupae). The antibacterial properties of Ch-AgNP were proved against Bacillus subtilis, Klebsiella pneumoniae and Salmonella typhi, while no growth inhibition was reported in assays conducted on Proteus vulgaris. Concerning non-target effects, in standard laboratory considtions the predation efficiency of Danio rerio zebrafishes was 68.8% and 61.6% against I and II instar larvae of A. stephensi, respectively. In a Ch-AgNP-contaminated environment, fish predation was boosted to 89.5% and 77.3%, respectively. Quantitative analysis of antioxidant enzymes SOD, CAT and LPO from hepatopancreas of fresh water crabs Paratelphusa hydrodromous exposed for 16 days to a Ch-AgNP-contaminated aquatic environment were conducted. Notably, deleterious effects of Ch-AgNP contaminating aquatic enviroment on the non-target crab P. hydrodromous were observed, particularly when doses higher than 8-10ppm are tested. Overall, this research highlights the potential of Ch-AGNP for the development of newer control tools against young instar populations of malaria mosquitoes, also highlighting some risks concerned the employ of nanoparticles in aquatic environments. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Folic Acid Conjugated Chitosan for Targeted Delivery of siRNA to Activated Macrophages in vitro and in vivo

    DEFF Research Database (Denmark)

    Yang, Chuanxu; Gao, Shan; Kjems, Jørgen

    2014-01-01

    was conjugated to chitosan (FA–CS) and used to formulate siRNA into nanoparticles capable of cell specific delivery. The physiochemical properties of the nanoparticles, including size, zeta-potential and encapsulation efficiency, were characterized and the intracellular uptake and gene silencing efficiency were...

  9. Preparation, Characterization, and Optimization of Folic Acid-Chitosan-Methotrexate Core-Shell Nanoparticles by Box-Behnken Design for Tumor-Targeted Drug Delivery.

    Science.gov (United States)

    Naghibi Beidokhti, Hamid Reza; Ghaffarzadegan, Reza; Mirzakhanlouei, Sasan; Ghazizadeh, Leila; Dorkoosh, Farid Abedin

    2017-01-01

    The objective of this study was to investigate the combined influence of independent variables in the preparation of folic acid-chitosan-methotrexate nanoparticles (FA-Chi-MTX NPs). These NPs were designed and prepared for targeted drug delivery in tumor. The NPs of each batch were prepared by coaxial electrospray atomization method and evaluated for particle size (PS) and particle size distribution (PSD). The independent variables were selected to be concentration of FA-chitosan, ratio of shell solution flow rate to core solution flow rate, and applied voltage. The process design of experiments (DOE) was obtained with three factors in three levels by Design expert software. Box-Behnken design was used to select 15 batches of experiments randomly. The chemical structure of FA-chitosan was examined by FTIR. The NPs of each batch were collected separately, and morphologies of NPs were investigated by field emission scanning electron microscope (FE-SEM). The captured pictures of all batches were analyzed by ImageJ software. Mean PS and PSD were calculated for each batch. Polynomial equation was produced for each response. The FE-SEM results showed the mean diameter of the core-shell NPs was around 304 nm, and nearly 30% of the produced NPs are in the desirable range. Optimum formulations were selected. The validation of DOE optimization results showed errors around 2.5 and 2.3% for PS and PSD, respectively. Moreover, the feasibility of using prepared NPs to target tumor extracellular pH was shown, as drug release was greater in the pH of endosome (acidic medium). Finally, our results proved that FA-Chi-MTX NPs were active against the human epithelial cervical cancer (HeLa) cells.

  10. 3D Porous Chitosan-Alginate Scaffolds as an In Vitro Model for Evaluating Nanoparticle-Mediated Tumor Targeting and Gene Delivery to Prostate Cancer.

    Science.gov (United States)

    Wang, Kui; Kievit, Forrest M; Florczyk, Stephen J; Stephen, Zachary R; Zhang, Miqin

    2015-10-12

    Cationic nanoparticles (NPs) for targeted gene delivery are conventionally evaluated using 2D in vitro cultures. However, this does not translate well to corresponding in vivo studies because of the marked difference in NP behavior in the presence of the tumor microenvironment. In this study, we investigated whether prostate cancer (PCa) cells cultured in three-dimensional (3D) chitosan-alginate (CA) porous scaffolds could model cationic NP-mediated gene targeted delivery to tumors in vitro. We assessed in vitro tumor cell proliferation, formation of tumor spheroids, and expression of marker genes that promote tumor malignancy in CA scaffolds. The efficacy of NP-targeted gene delivery was evaluated in PCa cells in 2D cultures, PCa tumor spheroids grown in CA scaffolds, and PCa tumors in a mouse TRAMP-C2 flank tumor model. PCa cells cultured in CA scaffolds grew into tumor spheroids and displayed characteristics of higher malignancy as compared to those in 2D cultures. Significantly, targeted gene delivery was only observed in cells cultured in CA scaffolds, whereas cells cultured on 2D plates showed no difference in gene delivery between targeted and nontarget control NPs. In vivo NP evaluation confirmed targeted gene delivery, indicating that only CA scaffolds correctly modeled NP-mediated targeted delivery in vivo. These findings suggest that CA scaffolds serve as a better in vitro platform than 2D cultures for evaluation of NP-mediated targeted gene delivery to PCa.

  11. Pectin-zinc-chitosan-polyethylene glycol colloidal nano-suspension as a food grade carrier for colon targeted delivery of resveratrol.

    Science.gov (United States)

    Andishmand, Hashem; Tabibiazar, Mahnaz; Mohammadifar, Mohammad Amin; Hamishehkar, Hamed

    2017-04-01

    The aim of the present study was to develop chitosan-zinc-pectinate-polyethylene glycol (PEG) nanoparticles (NPs) for colon-targeted delivery of resveratrol. The effects of pectin:ZnCl 2 :chitosan (PZnC) % w/v, pH and ionic strength of media, and addition of PEG on the colloidal stability and release behavior of resveratrol from NPs were examined by Zeta potential, particle size analyzer, scanning electron microscopy (SEM), and Fourier transform-infrared (FTIR) methods. The particle size and Zeta potential of PZnC NPs in the ratio of 10:1:3% w/v were 399±18nm and +25±1mV, respectively. The addition of PEG to PZnC as a solvent for resveratrol (10% w/v) noticeably decreased the size of NPs to approximately 83±4nm. More than 63% of the resveratrol was encapsulated into the developed NPs; furthermore, a low amount of resveratrol was released during one month, using simulated juice model (pH=4) as investigated by High Performance Liquid Chromatography (HPLC) analysis of resveratrol.The remaining resveratrol in NPs (∼49%) was released in simulated colon fluid in the presence of pectinase. These NPs can be introduced as a novel platform for successful colon delivery of resveratrol in fruit juice matrix. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Overcoming cisplatin resistance in non-small cell lung cancer with Mad2 silencing siRNA delivered systemically using EGFR-targeted chitosan nanoparticles.

    Science.gov (United States)

    Nascimento, Ana Vanessa; Singh, Amit; Bousbaa, Hassan; Ferreira, Domingos; Sarmento, Bruno; Amiji, Mansoor M

    2017-01-01

    Efficiency of chemotherapy is often limited by low therapeutic index of the drug as well as emergence of inherent and acquired drug resistance in cancer cells. As a common strategy to overcome drug resistance, higher doses of chemo-agents are administered. However, adverse side effects are usually increased as a consequence. A potentially effective approach is to combine chemotherapy with other therapeutic strategies such as small interfering RNAs (siRNAs) that allow the use of lower yet efficient doses of the anticancer drugs. We previously developed epidermal growth factor receptor (EGFR)-targeted chitosan (CS) nanoparticles as a versatile delivery system for silencing the essential mitotic checkpoint gene Mad2, and induce cell death. Here, we tested this system as a single therapy and in combination with cisplatin in cisplatin sensitive and resistant lung cancer models, and characterized its in vivo efficacy and safety. Combination treatment resulted in significant improvement in tumor inhibition that was strikingly more effective in cisplatin-resistant tumors. Importantly, effective cisplatin dosage was dramatically reduced in the co-therapy regimen resulting in negligible toxic effects from the drug as confirmed by parameters such as body weight gain, biochemical markers of hepatic and renal function, and histopathology of liver/kidney/spleen tissues. Overall, we demonstrate that the combination of Mad2 siRNA-loaded CS nanoparticles strategy with chemotherapeutic agents such as cisplatin constitutes an efficient and safe approach for the treatment of drug resistant tumors. Lung cancer remains one of the leading killers in the United States and around the world. Platinum agents, including cisplatin, are the first line treatment in lung cancer, including non-small cell lung cancer (NSCLC), which is the predominant form of lung cancer. In this study, we have evaluated Mad2 cell-cycle checkpoint gene silencing using small interfering RNA (siRNA) delivered

  13. Development of diclofenac sodium loaded magnetic nanocarriers of pectin interacted with chitosan for targeted and sustained drug delivery.

    Science.gov (United States)

    Dutta, Raj Kumar; Sahu, Saurabh

    2012-09-01

    A novel spherical magnetic nanocarrier of 100-150 nm dimensions made of pectin interacted with chitosan (MPCh-DS0.05) resulted in 99.5% encapsulation efficiency of diclofenac sodium (DS) as a model drug. Similarly, magnetic nanocarrier made of only pectin crosslinked with Ca(2+) (MPDS-0.05) resulted in only 60.6% encapsulation efficiency of DS. The increase in drug encapsulation efficiency (%) in MPCh-DS0.05 batch was due to synergistic drug encapsulation properties of pectin and chitosan. The structural and morphological features of these magnetic nanocarriers were studied by X-ray diffractometry (XRD), Fourier transform infrared-spectrometry (FT-IR), thermogravimetry, electron microscopy and dynamic light scattering (DLS) measurements. The magnetic properties were measured by vibrating sample magnetometer (VSM) and superconducting quantum unit interference device measurements (SQUID). The in vitro drug release was pH sensitive and exhibited sustained release sequentially in simulated gastric fluid (negligible release in 0-2h), simulated intestinal fluid (~69% release in 2-5h), simulated colonic fluid (5-60 h) and also in phosphate buffer at pH 7.4 (0-48 h). The drug release profile in phosphate buffer solution at pH 7.4 was in good agreement with swelling controlled mechanism on the basis of Korsemeyer-Peppas model. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Development of antibody-modified chitosan nanoparticles for the targeted delivery of siRNA across the blood-brain barrier as a strategy for inhibiting HIV replication in astrocytes.

    Science.gov (United States)

    Gu, Jijin; Al-Bayati, Karam; Ho, Emmanuel A

    2017-08-01

    RNA interference (RNAi)-mediated gene silencing offers a novel treatment and prevention strategy for human immunodeficiency virus (HIV) infection. HIV was found to infect and replicate in human brain cells and can cause neuroinfections and neurological deterioration. We designed dual-antibody-modified chitosan/small interfering RNA (siRNA) nanoparticles to deliver siRNA across the blood-brain barrier (BBB) targeting HIV-infected brain astrocytes as a strategy for inhibiting HIV replication. We hypothesized that transferrin antibody and bradykinin B2 antibody could specifically bind to the transferrin receptor (TfR) and bradykinin B2 receptor (B2R), respectively, and deliver siRNA across the BBB into astrocytes as potential targeting ligands. In this study, chitosan nanoparticles (CS-NPs) were prepared by a complex coacervation method in the presence of siRNA, and antibody was chemically conjugated to the nanoparticles. The antibody-modified chitosan nanoparticles (Ab-CS-NPs) were spherical in shape, with an average particle size of 235.7 ± 10.2 nm and a zeta potential of 22.88 ± 1.78 mV. The therapeutic potential of the nanoparticles was evaluated based on their cellular uptake and gene silencing efficiency. Cellular accumulation and gene silencing efficiency of Ab-CS-NPs in astrocytes were significantly improved compared to non-modified CS-NPs and single-antibody-modified CS-NPs. These results suggest that the combination of anti-Tf antibody and anti-B2 antibody significantly increased the knockdown effect of siRNA-loaded nanoparticles. Thus, antibody-mediated dual-targeting nanoparticles are an efficient and promising delivery strategy for inhibiting HIV replication in astrocytes. Graphical abstract Graphic representation of dual-antibody-conjugated chitosan nanoparticles for the targeted delivery of siRNA across the blood-brain barrier (BBB) for inhibiting HIV replication in astrocytes. a Nanoparticle delivery to the BBB and penetration. b Tf

  15. Chitosan-based nanoparticles for survivin targeted siRNA delivery in breast tumor therapy and preventing its metastasis.

    Science.gov (United States)

    Sun, Ping; Huang, Wei; Jin, Mingji; Wang, Qiming; Fan, Bo; Kang, Lin; Gao, Zhonggao

    Nanoparticle-mediated small interfering RNA (siRNA) delivery is a promising therapeutic strategy in various cancers. However, it is difficult to deliver degradative siRNA to tumor tissue, and thus a safe and efficient vector for siRNA delivery is essential for cancer therapy. In this study, poly(ethylene glycol)-modified chitosan (PEG-CS) was synthesized successfully for delivering nucleic acid drug. We deemed that PEGylated CS could improve its solubility by forming a stable siRNA loaded in nanoparticles, and enhancing transfection efficiency of siRNA-loaded CS nanoparticles in cancer cell line. The research results showed that siRNA loaded in PEGylated CS (PEG-CS/siRNA) nanoparticles with smaller particle size had superior structural stability in the physical environment compared to CS nanoparticles. The data of in vitro antitumor activity revealed that 4T1 tumor cell growth was significantly inhibited and cellular uptake of PEG-CS/siRNA nanoparticles in 4T1 cells was dramatically enhanced compared to naked siRNA groups. The results from flow cytometry and confocal laser scanning microscopy showed that PEG-CS/siRNA nanoparticles were more easily taken up than naked siRNA. Importantly, PEG-CS/siRNA nanoparticles significantly reduced the growth of xenograft tumors of 4T1 cells in vivo. It has been demonstrated that the PEG-CS is a safe and efficient vector for siRNA delivery, and it can effectively reduce tumor growth and prevent metastasis.

  16. Chitosan magnetic nanoparticles for drug delivery systems.

    Science.gov (United States)

    Assa, Farnaz; Jafarizadeh-Malmiri, Hoda; Ajamein, Hossein; Vaghari, Hamideh; Anarjan, Navideh; Ahmadi, Omid; Berenjian, Aydin

    2017-06-01

    The potential of magnetic nanoparticles (MNPs) in drug delivery systems (DDSs) is mainly related to its magnetic core and surface coating. These coatings can eliminate or minimize their aggregation under physiological conditions. Also, they can provide functional groups for bioconjugation to anticancer drugs and/or targeted ligands. Chitosan, as a derivative of chitin, is an attractive natural biopolymer from renewable resources with the presence of reactive amino and hydroxyl functional groups in its structure. Chitosan nanoparticles (NPs), due to their huge surface to volume ratio as compared to the chitosan in its bulk form, have outstanding physico-chemical, antimicrobial and biological properties. These unique properties make chitosan NPs a promising biopolymer for the application of DDSs. In this review, the current state and challenges for the application magnetic chitosan NPs in drug delivery systems were investigated. The present review also revisits the limitations and commercial impediments to provide insight for future works.

  17. M cell-targeting strategy facilitates mucosal immune response and enhances protection against CVB3-induced viral myocarditis elicited by chitosan-DNA vaccine.

    Science.gov (United States)

    Ye, Ting; Yue, Yan; Fan, Xiangmei; Dong, Chunsheng; Xu, Wei; Xiong, Sidong

    2014-07-31

    Efficient delivery of antigen to mucosal associated lymphoid tissue is a first and critical step for successful induction of mucosal immunity by vaccines. Considering its potential transcytotic capability, M cell has become a more and more attractive target for mucosal vaccines. In this research, we designed an M cell-targeting strategy by which mucosal delivery system chitosan (CS) was endowed with M cell-targeting ability via conjugating with a CPE30 peptide, C terminal 30 amino acids of clostridium perfringens enterotoxin (CPE), and then evaluated its immune-enhancing ability in the context of coxsackievirus B3 (CVB3)-specific mucosal vaccine consisting of CS and a plasmid encoding CVB3 predominant antigen VP1. It had shown that similar to CS-pVP1, M cell-targeting CPE30-CS-pVP1 vaccine appeared a uniform spherical shape with about 300 nm diameter and +22 mV zeta potential, and could efficiently protect DNA from DNase I digestion. Mice were orally immunized with 4 doses of CPE30-CS-pVP1 containing 50 μg pVP1 at 2-week intervals and challenged with CVB3 4 weeks after the last immunization. Compared with CS-pVP1 vaccine, CPE30-CS-pVP1 vaccine had no obvious impact on CVB3-specific serum IgG level and splenic T cell immune responses, but significantly increased specific fecal SIgA level and augmented mucosal T cell immune responses. Consequently, much milder myocarditis and lower viral load were witnessed in CPE30-CS-pVP1 immunized group. The enhanced immunogenicity and immunoprotection were associated with the M cell-targeting ability of CPE30-CS-pVP1 which improved its mucosal uptake and transcytosis. Our findings indicated that CPE30-CS-pVP1 may represent a novel prophylactic vaccine against CVB3-induced myocarditis, and this M cell-targeting strategy indeed could be applied as a promising and universal platform for mucosal vaccine development. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Radiation degradation of chitosan

    International Nuclear Information System (INIS)

    Norzita Yacob; Maznah Mahmud; Norhashidah Talip; Kamarudin Bahari; Kamaruddin Hashim; Khairul Zaman Dahlan

    2010-01-01

    In order to obtain an oligo chitosan, degradation of chitosan s were carried out in solid state and liquid state. The effects of an irradiation on the molecular weight and viscosity of the chitosan were investigated using Ubbelohde Capillary Viscometer and Brookfield Viscometer respectively. The molecular weight and viscosity of the chitosan s were decreased with an increase in the irradiation dose. In the presence of hydrogen peroxide, the molecular weight of chitosan can be further decreased. (author)

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

    Science.gov (United States)

    Islam, Nazrul; Ferro, Vito

    2016-07-01

    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.

  20. Nuclear imaging evaluation of galactosylation of chitosan

    International Nuclear Information System (INIS)

    Jeong, Hwan Jeong; Kim, Eun Mi; Kim, Chang Guhn; Park, In Kyu; Cho, Chong Su; Bom, Hee Seung

    2004-01-01

    Chitosan has been studied as a non-viral gene delivery vector, drug delivery carrier, metal chelater, food additive, and radiopharmaceutical, among other things. Recently, galactose-graft chitosan was studied as a non-viral gene and drug delivery vector to target hepatocytes. The aim of this study was to investigate the usefulness of nuclear imaging for in vivo evaluation of targeting the hepatocyte by galactose grafting. Galactosyl methylated chitosan (GMC) was produced by methylation to lactobionic acid coupled chitosan Cytotoxicity of 99 mTc-GMC was determined by MTT assay. Rabbits were injected via their auricular vein with 99 mTc-GMC and 99 mTc-methylated chitosan (MC), the latter of which does not contain a galactose group, and images were acquired with a gamma camera equipped with a parallel hole collimator. The composition of the galactose group in galactosylated chitosan (GC), as well as the tri-, di-, or mono-methylation of GMC, was confirmed by NMR spectroscopy. The results of MTT assay indicated that 99 mTc-GMC was non-toxic. 99 mTc-GMC specifically accumulated in the liver within 10 minutes of injection and maintained high hepatic uptake. In contrast, 99 mTc-MC showed faint liver uptake. 99 mTc-GMC scintigraphy of rabbits showed that the galactose ligand principally targeted the liver while the chitosan functionalities led to excretion through the urinary system. Bioconjugation with a specific ligand endows some degree of targetability to an administered molecule or drug, as in the case of galactose for hepatocyte in vivo, and evaluating said targetability is a clear example of the great benefit proffered by nuclear imaging

  1. Surface grafted chitosan gels. Part I. Molecular insight into the formation of chitosan and poly(acrylic acid) multilayers

    DEFF Research Database (Denmark)

    Liu, Chao; Thormann, Esben; Claesson, Per M.

    2014-01-01

    Composite polyelectrolyte multilayers of chitosan and low molecular weight poly(acrylic acid) (PAA) have been assembled by sequential adsorption as a first step toward building a surface anchored chitosan gel. Silane chemistry was used to graft the first chitosan layer to prevent film detachment...... and decomposition. The assembly process is characterized by nonlinear growth behavior, with different adsorption kinetics for chitosan and PAA. In situ analysis of the multilayer by means of surface sensitive total internal reflection Raman (TIRR) spectroscopy, combined with target factor analysis of the spectra...... molecular weight chitosan shows a similar behavior, although to a much lower extent. Our data demonstrate that the charged monomeric units of chitosan are mainly compensated by carboxylate ions from PAA. Furthermore, the morphology and mechanical properties of the multilayers were investigated in situ using...

  2. Omics for Investigating Chitosan as an Antifungal and Gene Modulator

    Directory of Open Access Journals (Sweden)

    Federico Lopez-Moya

    2016-03-01

    Full Text Available Chitosan is a biopolymer with a wide range of applications. The use of chitosan in clinical medicine to control infections by fungal pathogens such as Candida spp. is one of its most promising applications in view of the reduced number of antifungals available. Chitosan increases intracellular oxidative stress, then permeabilizes the plasma membrane of sensitive filamentous fungus Neurospora crassa and yeast. Transcriptomics reveals plasma membrane homeostasis and oxidative metabolism genes as key players in the response of fungi to chitosan. A lipase and a monosaccharide transporter, both inner plasma membrane proteins, and a glutathione transferase are main chitosan targets in N. crassa. Biocontrol fungi such as Pochonia chlamydosporia have a low content of polyunsaturated free fatty acids in their plasma membranes and are resistant to chitosan. Genome sequencing of P. chlamydosporia reveals a wide gene machinery to degrade and assimilate chitosan. Chitosan increases P. chlamydosporia sporulation and enhances parasitism of plant parasitic nematodes by the fungus. Omics studies allow understanding the mode of action of chitosan and help its development as an antifungal and gene modulator.

  3. Surface modification of protein enhances encapsulation in chitosan nanoparticles

    Science.gov (United States)

    Koyani, Rina D.; Andrade, Mariana; Quester, Katrin; Gaytán, Paul; Huerta-Saquero, Alejandro; Vazquez-Duhalt, Rafael

    2018-04-01

    Chitosan nanoparticles have a huge potential as nanocarriers for environmental and biomedical purposes. Protein encapsulation in nano-sized chitosan provides protection against inactivation, proteolysis, and other alterations due to environmental conditions, as well as the possibility to be targeted to specific tissues by ligand functionalization. In this work, we demonstrate that the chemical modification of the protein surface enhances the protein loading in chitosan nanocarriers. Encapsulation of green fluorescent protein and the cytochrome P450 was studied. The increase of electrostatic interactions between the free amino groups of chitosan and the increased number of free carboxylic groups in the protein surface enhance the protein loading, protein retention, and, thus, the enzymatic activity of chitosan nanoparticles. The chemical modification of protein surface with malonic acid moieties reduced drastically the protein isoelectric point increasing the protein interaction with the polycationic biomaterial and chitosan. The chemical modification of protein does not alter the morphology of chitosan nanoparticles that showed an average diameter of 18 nm, spheroidal in shape, and smooth surfaced. The strategy of chemical modification of protein surface, shown here, is a simple and efficient technique to enhance the protein loading in chitosan nanoparticles. This technique could be used for other nanoparticles based on polycationic or polyanionic materials. The increase of protein loading improves, doubtless, the performance of protein-loaded chitosan nanoparticles for biotechnological and biomedical applications.

  4. Chitosan microspheres in novel drug delivery systems.

    Science.gov (United States)

    Mitra, Analava; Dey, Baishakhi

    2011-07-01

    The main aim in the drug therapy of any disease is to attain the desired therapeutic concentration of the drug in plasma or at the site of action and maintain it for the entire duration of treatment. A drug on being used in conventional dosage forms leads to unavoidable fluctuations in the drug concentration leading to under medication or overmedication and increased frequency of dose administration as well as poor patient compliance. To minimize drug degradation and loss, to prevent harmful side effects and to increase drug bioavailability various drug delivery and drug targeting systems are currently under development. Handling the treatment of severe disease conditions has necessitated the development of innovative ideas to modify drug delivery techniques. Drug targeting means delivery of the drug-loaded system to the site of interest. Drug carrier systems include polymers, micelles, microcapsules, liposomes and lipoproteins to name some. Different polymer carriers exert different effects on drug delivery. Synthetic polymers are usually non-biocompatible, non-biodegradable and expensive. Natural polymers such as chitin and chitosan are devoid of such problems. Chitosan comes from the deacetylation of chitin, a natural biopolymer originating from crustacean shells. Chitosan is a biocompatible, biodegradable, and nontoxic natural polymer with excellent film-forming ability. Being of cationic character, chitosan is able to react with polyanions giving rise to polyelectrolyte complexes. Hence chitosan has become a promising natural polymer for the preparation of microspheres/nanospheres and microcapsules. The techniques employed to microencapsulate with chitosan include ionotropic gelation, spray drying, emulsion phase separation, simple and complex coacervation. This review focuses on the preparation, characterization of chitosan microspheres and their role in novel drug delivery systems.

  5. Chitosan derivatives with antimicrobial, antitumour and antioxidant activities--a review.

    Science.gov (United States)

    Jarmila, Vinsová; Vavríková, Eva

    2011-01-01

    Chitosan is a linear polysaccharide with a good biodegradability, biocompatibility, and no toxicity, which provide it with huge potential for future development. The chitosan molecule appears to be a suitable polymeric complex for many biomedical applications. This review gathers current findings on the antibacterial, antifungal, antitumour and antioxidant activities of chitosan derivatives and concurs with our previous review presenting data collected up to 2008. Antibacterial activity is based on molecular weight, the degree of deacetylation, the type of substitutents, which can be cationic or easily form cations, and the type of bacterium. In general, high molecular weight chitosan cannot pass through cell membranes and forms a film that protects cells against nutrient transport through the microbial cell membrane. Low molecular weight chitosan derivatives are water soluble and can better incorporate the active molecule into the cell. Gram-negative bacteria, often represented by Escherichia coli, have an anionic bacterial surface on which cationic chitosan derivatives interact electrostatically. Thus, many chitosan conjugates have cationic components such as ammonium, pyridinium or piperazinium substituents introduced into their molecules to increase their positive charge. Gram-positive bacteria like Staphylococcus aureus are inhibited by the binding of lower molecular weight chitosan derivatives to DNA or RNA. Chitosan nanoparticles exhibit an increase in loading capacity and efficacy. Antitumour active compounds such as doxorubicin, paclitaxel, docetaxel and norcantharidin are used as drug carriers. It is evident that chitosan, with its low molecular weight, is a useful carrier for molecular drugs requiring targeted delivery. The antioxidant scavenging activity of chitosan has been established by the strong hydrogen-donating ability of chitosan. The low molecular weight and greater degree of quarternization have a positive influence on the antioxidant activity

  6. Assessment of chitosan-affected metabolic response by peroxisome proliferator-activated receptor bioluminescent imaging-guided transcriptomic analysis.

    Directory of Open Access Journals (Sweden)

    Chia-Hung Kao

    Full Text Available Chitosan has been widely used in food industry as a weight-loss aid and a cholesterol-lowering agent. Previous studies have shown that chitosan affects metabolic responses and contributes to anti-diabetic, hypocholesteremic, and blood glucose-lowering effects; however, the in vivo targeting sites and mechanisms of chitosan remain to be clarified. In this study, we constructed transgenic mice, which carried the luciferase genes driven by peroxisome proliferator-activated receptor (PPAR, a key regulator of fatty acid and glucose metabolism. Bioluminescent imaging of PPAR transgenic mice was applied to report the organs that chitosan acted on, and gene expression profiles of chitosan-targeted organs were further analyzed to elucidate the mechanisms of chitosan. Bioluminescent imaging showed that constitutive PPAR activities were detected in brain and gastrointestinal tract. Administration of chitosan significantly activated the PPAR activities in brain and stomach. Microarray analysis of brain and stomach showed that several pathways involved in lipid and glucose metabolism were regulated by chitosan. Moreover, the expression levels of metabolism-associated genes like apolipoprotein B (apoB and ghrelin genes were down-regulated by chitosan. In conclusion, these findings suggested the feasibility of PPAR bioluminescent imaging-guided transcriptomic analysis on the evaluation of chitosan-affected metabolic responses in vivo. Moreover, we newly identified that downregulated expression of apoB and ghrelin genes were novel mechanisms for chitosan-affected metabolic responses in vivo.

  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...... of 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 ... 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. 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.

  9. The role of chitosan on oral delivery of peptide-loaded nanoparticle formulation.

    Science.gov (United States)

    Wong, Chun Y; Al-Salami, Hani; Dass, Crispin R

    2017-12-01

    Therapeutic peptides are conventionally administered via subcutaneous injection. Chitosan-based nanoparticles are gaining increased attention for their ability to serve as a carrier for oral delivery of peptides and vaccination. They offered superior biocompatibiltiy, controlled drug release profile and facilitated gastrointestinal (GI) absorption. The encapsulated peptides can withstand enzymatic degradation and various pH. Chitosan-based nanoparticles can also be modified by ligand conjugation to the surface of nanoparticle for transcellular absorption and specific-targeted delivery of macromolecules to the tissue of interest. Current research suggests that chitosan-based nanoparticles can deliver therapeutic peptide for the treatment of several medical conditions such as diabetes, bacterial infection and cancer. This review summarises the role of chitosan in oral nanoparticle delivery and identifies the clinical application of peptide-loaded chitosan-based nanoparticles.

  10. Fabrication of chitosan microparticles loaded in chitosan and poly

    Indian Academy of Sciences (India)

    In recent decades, the use of microparticle-mediated drug delivery is widely applied in the field of biomedicalapplication. Here, we report the new dressing material with ciprofloxacin-loaded chitosan microparticle (CMP) impregnatedin chitosan (CH) and poly(vinyl alcohol) (PVA) scaffold for effective delivery of drug in a ...

  11. Heavy Metal Removal by Chitosan and Chitosan Composite

    International Nuclear Information System (INIS)

    Abdel-Mohdy, F.A.; El-Sawy, S.; Ibrahim, M.S.

    2005-01-01

    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 Cu 2+ 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 Cu 2+ than the other metal ion. Limited grafting of DEAEMA polymer -containing specific functional groups-onto the chitosan backbone improves the sorption performance

  12. Gadolinium-loaded gel scintillators for neutron and antineutrino detection

    Science.gov (United States)

    Riddle, Catherine Lynn; Akers, Douglas William; Demmer, Ricky Lynn; Paviet, Patricia Denise; Drigert, Mark William

    2016-11-29

    A gadolinium (Gd) loaded scintillation gel (Gd-ScintGel) compound allows for neutron and gamma-ray detection. The unique gel scintillator encompasses some of the best features of both liquid and solid scintillators, yet without many of the disadvantages associated therewith. Preferably, the gel scintillator is a water soluble Gd-DTPA compound and water soluble fluorophores such as: CdSe/ZnS (or ZnS) quantum dot (Q-dot) nanoparticles, coumarin derivatives 7-hydroxy-4-methylcoumarin, 7-hydroxy-4-methylcoumarin-3-acetic acid, 7-hydroxycoumarin-3-carboxylic acid, and Alexa Fluor 350 as well as a carbostyril compound, carbostyril 124 in a stable water-based gel, such as methylcellulose or polyacrylamide polymers. The Gd-loaded ScintGel allows for a homogenious distribution of the Gd-DTPA and the fluorophores, and yields clean fluorescent emission peaks. A moderator, such as deuterium or a water-based clear polymer, can be incorporated in the Gd-ScintGel. The gel scintillators can be used in compact detectors, including neutron and antineutrino detectors.

  13. Chitosan-based nanosystems and their exploited antimicrobial activity.

    Science.gov (United States)

    Perinelli, Diego Romano; Fagioli, Laura; Campana, Raffaella; Lam, Jenny K W; Baffone, Wally; Palmieri, Giovanni Filippo; Casettari, Luca; Bonacucina, Giulia

    2018-05-30

    Chitosan is a biodegradable and biocompatible natural polysaccharide that has a wide range of applications in the field of pharmaceutics, biomedical, chemical, cosmetics, textile and food industry. One of the most interesting characteristics of chitosan is its antibacterial and antifungal activity, and together with its excellent safety profile in human, it has attracted considerable attention in various research disciplines. The antimicrobial activity of chitosan is dependent on a number of factors, including its molecular weight, degree of deacetylation, degree of substitution, physical form, as well as structural properties of the cell wall of the target microorganisms. While the sole use of chitosan may not be sufficient to produce an adequate antimicrobial effect to fulfil different purposes, the incorporation of this biopolymer with other active substances such as drugs, metals and natural compounds in nanosystems is a commonly employed strategy to enhance its antimicrobial potential. In this review, we aim to provide an overview on the different approaches that exploit the antimicrobial activity of chitosan-based nanosystems and their applications, and highlight the latest advances in this field. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Chitosan-based nanocomposites

    CSIR Research Space (South Africa)

    Kesavan Pillai, Sreejarani

    2012-08-01

    Full Text Available , and hygiene devices. They thus represent a strong and emerging answer for improved and eco-friendly materials. This chapter reviews the recent developments in the area of chitosan-based nanocomposites, with a special emphasis on clay-containing nanocomposites...-sized mineral fillers like silica, talc, and clay are added to reduce the cost and improve chitosan’s performance in some way. However, the mechanical properties such as elongation at break and tensile strength of these composites decrease with the incorporation...

  15. Gelatin/chitosan biofilm: preparation and characterization

    International Nuclear Information System (INIS)

    Trindade, Luciane da C.; Nunes, Raquel A.; Diniz, Nadie K.S.; Braga, Carla R.C.; Silva, Suedina M. de Lima

    2011-01-01

    In this study, gelatin, chitosan and gelatin/chitosan bio films using the ratio of gelatin/chitosan (50/50) were prepared by casting method. The bio films prepared were characterized by X-ray diffraction, scanning electron microscopy and dissolution ratio. According to the results, the incorporation of chitosan into gelatin indicate the decrease of crystallinity of chitosan, a compact structure without large pores and that the dissolution of gelatin/chitosan film is little influenced by hot water than gelatin films. (author)

  16. Encapsulation of testosterone by chitosan nanoparticles.

    Science.gov (United States)

    Chanphai, P; Tajmir-Riahi, H A

    2017-05-01

    The loading of testosterone by chitosan nanoparticles was investigated, using multiple spectroscopic methods, thermodynamic analysis, TEM images and modeling. Thermodynamic parameters showed testosterone-chitosan bindings occur mainly via H-bonding and van der Waals contacts. As polymer size increased more stable steroid-chitosan conjugates formed and hydrophobic contact was also observed. The loading efficacy of testosterone-nanocarrier was 40-55% and increased as chitosan size increased. Testosterone encapsulation markedly alters chitosan morphology. Chitosan nanoparticles are capable of transporting testosterone in vitro. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Chitosan microparticles for sustaining the topical delivery of minoxidil sulphate.

    Science.gov (United States)

    Gelfuso, Guilherme Martins; Gratieri, Taís; Simão, Patrícia Sper; de Freitas, Luís Alexandre Pedro; Lopez, Renata Fonseca Vianna

    2011-01-01

    Given the hypothesis that microparticles can penetrate the skin barrier along the transfollicular route, this work aimed to obtain and characterise chitosan microparticles loaded with minoxidil sulphate (MXS) and to study their ability to sustain the release of the drug, attempting a further application utilising them in a targeted delivery system for the topical treatment of alopecia. Chitosan microparticles, containing different proportions of MXS/polymer, were prepared by spray drying and were characterised by yield, encapsulation efficiency, size and morphology. Microparticles selected for further studies showed high encapsulation efficiency (∼82%), a mean diameter of 3.0 µm and a spherical morphology without porosities. When suspended in an ethanol/water solution, chitosan microparticles underwent instantaneous swelling, increasing their mean diameter by 90%. Release studies revealed that the chitosan microparticles were able to sustain about three times the release rate of MXS. This feature, combined with suitable size, confers to these microparticles the potential to target and improve topical therapy of alopecia with minoxidil.

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

    International Nuclear Information System (INIS)

    Tg Ahbrizal Farizal Tg Ahmad; Norimah Yusof; Kamarudin Bahari; Kamaruddin Hashim

    2006-01-01

    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)

  19. Heat applied chitosan treatment on hardwood chips to improve physical and mechanical properties of particleboard

    Directory of Open Access Journals (Sweden)

    Mehmet Altay Basturk

    2012-11-01

    Full Text Available High-heat treatment after surface application of chitosan was used in an effort to improve physical and mechanical performances of particleboard. Particleboard is mainly used in the furniture industry and also used as a home decoration material; however, it has a poor dimensional stability. In this work, hardwood chips were obtained from a commercial plant; half of the chips were used for the control panels without chitosan treatment, and the other half were treated with chitosan acetate solutions (2% wt. Those chitosan-treated particles were also exposed to extra high-heat (140oC treatment for 90 minutes to convert chitosan acetate back to chitin. Liquid phenol-formaldehyde resin was sprayed onto dry particles at a level of 6 and 7% (wt based upon oven-dry weight. The mat was pressed (200oC for 11 minutes to form 19 mm thickness and a target of 0.63 g cm-3 density panels. Thickness swelling, linear expansion, and water gain of the treated panels were reduced over untreated panels during a 24-hour water-soak test. In addition, chitosan-treated panels showed better internal bond strength than control panels. Static bending test results showed a negative effect for the chitosan treated particleboard.

  20. Radiation-induced changes in carboxymethylated chitosan

    International Nuclear Information System (INIS)

    Huang Ling; Peng Jing; Zhai Maolin; Li Jiuqiang; Wei Genshuan

    2007-01-01

    This study focuses on the radiation effect of γ-ray on carboxymethylated chitosan (CM-chitosan) in solid state. The changes in molecular weight of CM-chitosan with absorbed dose were monitored by viscosity method. Experimental results indicated that random chain scissions took place under irradiation. Radiation chemical yield (G d ) of CM-chitosan in solid state with N 2 -saturated was 0.49, which showed CM-chitosan has high radiation stability. Biomaterials composed of CM-chitosan can be thought to sterilize with low absorbed dose. FTIR and UV spectra showed that main chain structures of CM-chitosan were retained, carbonyl/carboxyl groups were formed and partial amino groups were eliminated in high absorbed dose. XRD patterns identified that the degradation of CM-chitosan occurred mostly in amorphous region

  1. Investigation of Galactosylated Low Molecular Weight Chitosan ...

    African Journals Online (AJOL)

    was coupled with low molecular weight chitosan (LMWC) using carbodiimide chemistry. .... High molecular weight chitosan (minimum 85% ..... membrane permeability of drug and mutual repulsion ... coating thickness and the lower solubility of.

  2. Physical Properties and Antibacterial Efficacy of Biodegradable Chitosan Films

    OpenAIRE

    中島, 照夫

    2009-01-01

    [Synopsis] Chitin, chitosan and quaternary chitosan films were prepared, and the physical properties and the antibacterial activities of chitosan and quaternary chitosan films were evaluated. The tensile strength of chitin films was 30~40% lower than that of chitosan films, but the crystallinity of chitin film was much higher than that of chitosan films. The crystallinity and orientation of crystallites were hardly affected by the four kinds of solvent chosen to cast chitosan films, but a de...

  3. 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)

  4. Application of irradiated chitosan for fruit preservation

    International Nuclear Information System (INIS)

    Lan, K.N.; Lam, N.D.; Kume, Tamikazu

    2000-01-01

    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. Chitosan as coagulant on cyanobacteria in lake restoration management may cause rapid cell lysis.

    Science.gov (United States)

    Mucci, Maíra; Noyma, Natalia Pessoa; de Magalhães, Leonardo; Miranda, Marcela; van Oosterhout, Frank; Guedes, Iamê Alves; Huszar, Vera L M; Marinho, Marcelo Manzi; Lürling, Miquel

    2017-07-01

    Combining coagulant and ballast to remove cyanobacteria from the water column is a promising restoration technique to mitigate cyanobacterial nuisance in surface waters. The organic, biodegradable polymer chitosan has been promoted as a coagulant and is viewed as non-toxic. In this study, we show that chitosan may rapidly compromise membrane integrity and kill certain cyanobacteria leading to release of cell contents in the water. A strain of Cylindrospermopsis raciborskii and one strain of Planktothrix agardhii were most sensitive. A 1.3 h exposure to a low dose of 0.5 mg l -1 chitosan already almost completely killed these cultures resulting in release of cell contents. After 24 h, reductions in PSII efficiencies of all cyanobacteria tested were observed. EC50 values varied from around 0.5 mg l -1 chitosan for the two sensitive strains, via about 5 mg l -1 chitosan for an Aphanizomenon flos-aquae strain, a toxic P. agardhii strain and two Anabaena cylindrica cultures, to more than 8 mg l -1 chitosan for a Microcystis aeruginosa strain and another A. flos-aquae strain. Differences in sensitivity to chitosan might be related to polymeric substances that surround cyanobacteria. Rapid lysis of toxic strains is likely and when chitosan flocking and sinking of cyanobacteria is considered in lake restoration, flocculation efficacy studies should be complemented with investigation on the effects of chitosan on the cyanobacteria assemblage being targeted. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  6. Design of Chitosan and Its Water Soluble Derivatives-Based Drug Carriers with Polyelectrolyte Complexes

    Directory of Open Access Journals (Sweden)

    Qing-Xi Wu

    2014-12-01

    Full Text Available Chitosan, the cationic polysaccharide derived from the natural polysaccharide chitin, has been studied as a biomaterial for more than two decades. As a polycationic polymer with favorable properties, it has been widely used to form polyelectrolyte complexes with polyanions for various applications in drug delivery fields. In recent years, a growing number of studies have been focused on the preparation of polyelectrolyte complexes based on chitosan and its water soluble derivatives. They have been considered well-suited as biomaterials for a number of vital drug carriers with targeted/controlled release profiles, e.g., films, capsules, microcapsules. In this work, an overview highlights not only the favorable properties of chitosan and its water soluble derivatives but also the good performance of the polyelectrolyte complexes produced based on chitosan. Their various types of applications as drug carriers are reviewed in detail.

  7. Design of chitosan and its water soluble derivatives-based drug carriers with polyelectrolyte complexes.

    Science.gov (United States)

    Wu, Qing-Xi; Lin, Dong-Qiang; Yao, Shan-Jing

    2014-12-19

    Chitosan, the cationic polysaccharide derived from the natural polysaccharide chitin, has been studied as a biomaterial for more than two decades. As a polycationic polymer with favorable properties, it has been widely used to form polyelectrolyte complexes with polyanions for various applications in drug delivery fields. In recent years, a growing number of studies have been focused on the preparation of polyelectrolyte complexes based on chitosan and its water soluble derivatives. They have been considered well-suited as biomaterials for a number of vital drug carriers with targeted/controlled release profiles, e.g., films, capsules, microcapsules. In this work, an overview highlights not only the favorable properties of chitosan and its water soluble derivatives but also the good performance of the polyelectrolyte complexes produced based on chitosan. Their various types of applications as drug carriers are reviewed in detail.

  8. Design of Chitosan and Its Water Soluble Derivatives-Based Drug Carriers with Polyelectrolyte Complexes

    Science.gov (United States)

    Wu, Qing-Xi; Lin, Dong-Qiang; Yao, Shan-Jing

    2014-01-01

    Chitosan, the cationic polysaccharide derived from the natural polysaccharide chitin, has been studied as a biomaterial for more than two decades. As a polycationic polymer with favorable properties, it has been widely used to form polyelectrolyte complexes with polyanions for various applications in drug delivery fields. In recent years, a growing number of studies have been focused on the preparation of polyelectrolyte complexes based on chitosan and its water soluble derivatives. They have been considered well-suited as biomaterials for a number of vital drug carriers with targeted/controlled release profiles, e.g., films, capsules, microcapsules. In this work, an overview highlights not only the favorable properties of chitosan and its water soluble derivatives but also the good performance of the polyelectrolyte complexes produced based on chitosan. Their various types of applications as drug carriers are reviewed in detail. PMID:25532565

  9. 5-Fluorouracil Encapsulated Chitosan Nanoparticles for pH-Stimulated Drug Delivery: Evaluation of Controlled Release Kinetics

    Directory of Open Access Journals (Sweden)

    R. Seda Tığlı Aydın

    2012-01-01

    Full Text Available Nanoparticles consisting of human therapeutic drugs are suggested as a promising strategy for targeted and localized drug delivery to tumor cells. In this study, 5-fluorouracil (5-FU encapsulated chitosan nanoparticles were prepared in order to investigate potentials of localized drug delivery for tumor environment due to pH sensitivity of chitosan nanoparticles. Optimization of chitosan and 5-FU encapsulated nanoparticles production revealed 148.8±1.1 nm and 243.1±17.9 nm particle size diameters with narrow size distributions, which are confirmed by scanning electron microscope (SEM images. The challenge was to investigate drug delivery of 5-FU encapsulated chitosan nanoparticles due to varied pH changes. To achieve this objective, pH sensitivity of prepared chitosan nanoparticle was evaluated and results showed a significant swelling response for pH 5 with particle diameter of ∼450 nm. In vitro release studies indicated a controlled and sustained release of 5-FU from chitosan nanoparticles with the release amounts of 29.1–60.8% due to varied pH environments after 408 h of the incubation period. pH sensitivity is confirmed by mathematical modeling of release kinetics since chitosan nanoparticles showed stimuli-induced release. Results suggested that 5-FU encapsulated chitosan nanoparticles can be launched as pH-responsive smart drug delivery agents for possible applications of cancer treatments.

  10. Gold nanoparticles stabilized by chitosan

    International Nuclear Information System (INIS)

    Geraldes, Adriana N.; Oliveira, Maria Jose A.; Silva, Andressa A. da; Leal, Jessica; Batista, Jorge G.S.; Lugao, Ademar B.

    2015-01-01

    In our laboratory has been growing the interest in studying gold nanoparticles and for this reason, the aim of this work is report the first results of the effect of chitosan as stabilizer in gold nanoparticle formulation. AuNPs were synthesized by reducing hydrogen tetrachloroaurate (HAuCl 4 ) using NaBH 4 or gamma irradiation (25kGy) as reduction agent. The chitosan (3 mol L -1 ) was added at 0.5; 1.0 and 1.5 mL. The gold nanoparticles were characterized by UV-Vis absorption spectroscopy, X-ray diffraction (XRD) and Transmission electron microscopy (TEM). Their physical stability was determined using a UV-Vis spectrophotometer over one week during storage at room temperature. Absorption measurements indicated that the plasmon resonance wavelength appears at a wavelength around 530 nm. Has been observed that Chitosan in such quantities were not effective in stabilizing the AuNPs. (author)

  11. Evaluation of the cytotoxic and genotoxic potential of lecithin/chitosan nanoparticles

    Science.gov (United States)

    Taner, Gökçe; Yeşilöz, Recep; Özkan Vardar, Deniz; Şenyiğit, Taner; Özer, Özgen; Degen, Gisela H.; Başaran, Nurşen

    2014-02-01

    Nanoparticles-based drug targeting delivery systems have been introduced in the treatment for various diseases because of their effective properties, although there have been conflicting results on the toxicity of nanoparticles. In the present study, the aim was to evaluate the cytotoxicity and the genotoxicity of different concentrations of lecithin/chitosan nanoparticles with and without clobetasol-17-propionate (CP) by neutral red uptake (NRU) cytotoxicity assay and single cell gel electrophoresis (Comet) and cytokinesis-blocked micronucleus assays. The IC50 values of lecithin/chitosan nanoparticles with/without CP were found as 1.9 and 1.8 %, respectively, in the NRU cytotoxicity test. High concentrations of lecithin/chitosan nanoparticles induced DNA damage in human lymphocytes as evaluated by comet assay. The micronucleus frequency was increased by the lecithin/chitosan treatment in a dose-dependent manner. Also at the two highest concentrations, a significant increase in micronucleus formation was observed. Lecithin/chitosan nanoparticles with CP did not increase the frequency of micronucleus and also did not induce additional DNA damage when compared with lecithin/chitosan nanoparticles without CP; therefore, CP itself has not found to be genotoxic at the studied concentration.

  12. Ethanolic extract of propolis for biodegradable films packaging enhanced with chitosan

    Science.gov (United States)

    Ismail, M. I.; Roslan, A.; Saari, N. S.; Hashim, K. H.; Kalamullah, M. R.

    2017-09-01

    The use of industrial organic waste which are chitosan and propolis as materials for the development of biodegradable and active packaging is economical and environmentally appealing. Processing of propolis-chitosan film can minimize waste, and produce low-cost added value biopolymer packaging films for targeted applications. This aims of this research is to develop and characterize a biodegradable films by incorporating chitosan with propolis extract to enhance the functional properties for potential use as active food packaging. The film's moisture content, solubility and antimicrobial activity increase due to increasing volume of propolis extract which are 0 ml, 1.2 ml and 2.4 ml of propolis extract. Propolis-chitosan film with 2.4 ml of propolis extract is more soluble in water compared to propolis-chitosan film with 0 ml of propolis extract and 1.2 ml of propolis extract. The higher the volume of the propolis extract used, the higher the solubility of film in the water. The moisture content also will increase when higher volume of propolis extract used. Characterization of moisture content, solubility and antimicrobial activities revealed the benefits of adding propolis extract into chitosan films and the potential of using the developed film as active food packaging.

  13. Interaction of chitin/chitosan with salivary and other epithelial cells-An overview.

    Science.gov (United States)

    Patil, Sharvari Vijaykumar; Nanduri, Lalitha S Y

    2017-11-01

    Chitin and its deacetylated form, chitosan, have been widely used for tissue engineering of both epithelial and mesenchymal tissues. Epithelial cells characterised by their sheet-like tight cellular arrangement and polarised nature, constitute a major component in various organs and play a variety of roles including protection, secretion and maintenance of tissue homeostasis. Regeneration of damaged epithelial tissues has been studied using biomaterials such as chitin, chitosan, hyaluronan, gelatin and alginate. Chitin and chitosan are known to promote proliferation of various embryonic and adult epithelial cells. However it is not clearly understood how this activity is achieved or what are the mechanisms involved in the chitin/chitosan driven proliferation of epithelial cells. Mechanistic understanding of influence of chitin/chitosan on epithelial cells will guide us to develop more targeted regenerative scaffold/hydrogel systems. Therefore, current review attempts to elicit a mechanistic insight into how chitin and chitosan interact with salivary, mammary, skin, nasal, lung, intestinal and bladder epithelial cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Development of a PVAl/chitosan composite membrane compatible with the dermo-epidermic system

    International Nuclear Information System (INIS)

    Almeida, Tiago Luiz de

    2009-03-01

    Due to the frequent incidence of people with skin lesions such as burns and ulcers and the lack of available donors, biomaterials with the capacity to mimic skin must be developed. In order to develop these biomaterials, polymers are used in the attempt to achieve characteristics which are closer to the target organ. In this direction, for several years our group has been developing dermo-epidermic substitutes, specifically biodegradable and biocompatible membranes made up of PVAl and chitosan. PVAl, a synthetic polymer, was used to imitate part of the human dermis and chitosan, a polymer of organic origin, was used in this study to stimulate growth and maintenance of the epidermis. Due to the variations of these commercially obtained polymers, the objective of this study was to characterize their physical and chemical properties, comparing them with the membrane previously obtained by our group with the intention of confirming the hypotheses of interferences put forward in this study. The PVAl membranes in the study (PVAl MP) that obtained characteristics most similar to the standard were those irradiated with 13 and 15 kGy; this last was chosen because it was the minimum dose necessary to achieve sterility. These membranes were also those which had the largest percentage of pores between 70 and 100 μm. For chitosan, the principal characteristics studied were the degree of acetylation (DA) and average molecular weight, both results demonstrated different characteristics than commercially indicated. Various membrane preparation protocols were carried out from the chitosan solution (2%). The membrane composed of the solution of chitosan homogenized with glycerol (20%) and dried at room temperature had the best interaction with keratinocytes. To finalize the study, this chitosan solution was poured over a PVAl membrane, lyophilized and impregnated with chitosan (2%) solution and the compound was kept at room temperature until a chitosan film formed on the upper

  15. Chitosan based metallic nanocomposite scaffolds as antimicrobial wound dressings.

    Science.gov (United States)

    Mohandas, Annapoorna; Deepthi, S; Biswas, Raja; Jayakumar, R

    2018-09-01

    Chitosan based nanocomposite scaffolds have attracted wider applications in medicine, in the area of drug delivery, tissue engineering and wound healing. Chitosan matrix incorporated with nanometallic components has immense potential in the area of wound dressings due to its antimicrobial properties. This review focuses on the different combinations of Chitosan metal nanocomposites such as Chitosan/nAg, Chitosan/nAu, Chitosan/nCu, Chitosan/nZnO and Chitosan/nTiO 2 towards enhancement of healing or infection control with special reference to the antimicrobial mechanism of action and toxicity.

  16. Irradiation gamma on chitosan films

    Energy Technology Data Exchange (ETDEWEB)

    Mello, Luana Miranda Lopes de; Souza, Adriana Regia Marques de; Arthur, Valter, E-mail: lumilopes@hotmail.com, E-mail: drilavras@yahoo.com.br, E-mail: arthur@cena.usp.br [Universidade Federal do Tocantins (UFT), Palmas,TO (Brazil). Departmento de Ciencia e Tecnologia de Alimentos; Universidade Federal de Goias (UFGO), Goiania (Brazil). Departmento de Ciencia e Tecnologia de Alimentos; Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)

    2017-11-01

    Films are preformed structures, independent, that are used to wrap food after processing, increasing their shelf life and enhancing its bright and attractive appearance. They are prepared from biological materials as an alternative to the plastic synthetic containers to improve the quality of the environment. Chitosan is a biodegradable polymer composed of β-(1-4) linked D-glucosamine (deacetylated unit) and N-acetyl-D- glucosamine (acetylated unit). It is produced commercially by deacetylation of chitin, which is a structural component of the exoskeleton of crustaceans. She is able to form films and edible and/or biodegradable coatings. With the objective to evaluate the effect of different doses of gamma radiation (0, 5, 10 and 15 kGy) and chitosan concentrations (1 and 2%) in film properties, it was evaluated its optical, mechanical and morphological properties. The films were produced by casting. Irradiation did not affect the thickness of the films, but influenced its colors, increasing the tone of the film for a stronger yellowish color. This fact can be attributed to the increased concentration of C = O bonds of chitosan due to the breakdown of the chain reaction and the Maillard reaction. Irradiated films showed smoother surface and less rough, due to the degradation of the chitosan molecule and poor mechanical properties, not showing good flexibility and stretching. (author)

  17. Irradiation gamma on chitosan films

    International Nuclear Information System (INIS)

    Mello, Luana Miranda Lopes de; Souza, Adriana Regia Marques de; Arthur, Valter

    2017-01-01

    Films are preformed structures, independent, that are used to wrap food after processing, increasing their shelf life and enhancing its bright and attractive appearance. They are prepared from biological materials as an alternative to the plastic synthetic containers to improve the quality of the environment. Chitosan is a biodegradable polymer composed of β-(1-4) linked D-glucosamine (deacetylated unit) and N-acetyl-D- glucosamine (acetylated unit). It is produced commercially by deacetylation of chitin, which is a structural component of the exoskeleton of crustaceans. She is able to form films and edible and/or biodegradable coatings. With the objective to evaluate the effect of different doses of gamma radiation (0, 5, 10 and 15 kGy) and chitosan concentrations (1 and 2%) in film properties, it was evaluated its optical, mechanical and morphological properties. The films were produced by casting. Irradiation did not affect the thickness of the films, but influenced its colors, increasing the tone of the film for a stronger yellowish color. This fact can be attributed to the increased concentration of C = O bonds of chitosan due to the breakdown of the chain reaction and the Maillard reaction. Irradiated films showed smoother surface and less rough, due to the degradation of the chitosan molecule and poor mechanical properties, not showing good flexibility and stretching. (author)

  18. Chitosan adsorption to salivary pellicles

    NARCIS (Netherlands)

    van der Mei, Henderina; Engels, Eefje; de Vries, Jacob; Dijkstra, Rene JB; Busscher, Hendrik

    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

  19. 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.

  20. Effect of Chitosan Properties on Immunoreactivity

    Science.gov (United States)

    Ravindranathan, Sruthi; Koppolu, Bhanu prasanth; 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 from various sources were treated with mouse and human APCs (macrophages and/or dendritic cells) and the amount of tumor necrosis factor-α (TNF-α) released by the cells was used as an indicator of immunoreactivity. Our results indicate that only endotoxin content and not DDA or viscosity influenced chitosan-induced immune responses. Our data also indicate that low endotoxin chitosan (chitosan in preclinical studies in order for this valuable biomaterial to achieve widespread clinical application. PMID:27187416

  1. Chitosan: A potential biopolymer for wound management.

    Science.gov (United States)

    Bano, Ijaz; Arshad, Muhammad; Yasin, Tariq; Ghauri, Muhammad Afzal; Younus, Muhammad

    2017-09-01

    It has been seen that slow healing and non-healing wounds conditions are treatable but still challenging to humans. Wound dressing usually seeks for biocompatible and biodegradable recipe. Natural polysaccharides like chitosan have been examined for its antimicrobial and healing properties on the basis of its variation in molecular weight and degree of deacetylation. Chitosan adopts some vital characteristics for treatment of various kinds of wounds which include its bonding nature, antifungal, bactericidal and permeability to oxygen. Chitosan therefore has been modified into various forms for the treatment of wounds and burns. The purpose of this review article is to understand the exploitation of chitosan and its derivatives as wound dressings. This article will also provide a concise insight on the properties of chitosan necessary for skin healing and regeneration, particularly highlighting the emerging role of chitosan films as next generation skin substitutes for the treatment of full thickness wounds. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Radiation depolymerization of chitosan to prepare oligomers

    International Nuclear Information System (INIS)

    Hai, Le; Bang Diep, Tran; Nagasawa, Naotsugu; Yoshii, Fumio; Kume, Tamikazu

    2003-01-01

    Radiation depolymerization of chitosan was carried out by gamma irradiation in the solid state. The radiation-chemical depolymerization yield of chitosan in the solid state, Gd, determined by gel permeation chromatography, is 0.9 for chitosan 10B and 1.8 for chitosan 8B. Low molecular weight chitosan/or oligochitosans were separated from a chitosan depolymerized by gamma radiation, using mixtures of methanol-water and acetone as the solvents. Due to the differences in solubility revealed upon radiolysis, extracts became subdivided into precipitates and soluble fractions. The biological effect of oligochitosan in each fraction was evaluated; the preliminary results indicated that the oligochitosan with M w -bar=2x10 4 inhibited the growth of fungi at 100 ppm and that with M w -bar=800 only enhanced the growth of the same typical fungi

  3. Radiation processing of chitosan derivative and its characteristics

    International Nuclear Information System (INIS)

    Kamarudin Bahari; Kamarolzaman Hussein; Kamaruddin Hashim; Khairul Zaman Mohd Dahlan

    2002-01-01

    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)

  4. Synthesis, characterization and radiation processing of carboxymethyl-chitosan

    International Nuclear Information System (INIS)

    Kamarudin Bahari; Kamarolzaman Hussein; Kamaruddin Hashim; Khairul Zaman Mohd Dahlan

    2002-01-01

    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)

  5. Structure and properties of microcrystalline chitosan

    International Nuclear Information System (INIS)

    Pighinelli, Luciano; Guimaraes, Fernando Machado; Paz, Luan Rios; Zanin, Gabrielle Brehm; Kmiec, Marzena; Tedesco, Felipe Melleu; Reis, Victoria Oliva dos; Silva, Matheus Machado; Becker, Cristiane Miotto; Zehetmeyer, Gislene; Rasia, Gisele

    2016-01-01

    Full text: The microcrystalline chitosan is a modified form of chitosan; it has been elaborated from obtaining method of chitosan salts. It is characterized by special properties of the initial chitosan such as biocompatibility, bioactivity, non-toxic, biodegradability [1]. The objective of this study is to develop a different method to obtain the microcrystalline chitosan and the following characterization of the initial chitosan and MCCh. The material was characterized by FTIR, scanning of electron microscopy, SEM, nuclear magnetic resonance, NMR, and x-ray diffraction. The results indicate that the process to obtain MCCh, did not change the structure of the initial chitosan. The MCCh shows the same functional groups of the initial chitosan. The NMR results shows the acetylated and deacetylated groups. The morphology shows a homogeneous structure of surface. The X-ray diffraction shows the reduction of the crystallinity in the MCCh, indicating a bigger amorphous structure of the MCCh. The chitosan and its derivatives are polymers with excellent properties to be used in regenerative medicine because of ensure efficiency in healing process. This polysaccharide has a great potential to develop a new generation of biomaterials that can be used in regenerative medicine and tissue engineering [2]. References: [1]. LI, Q. et al. Applications and properties of chitosan. In: GOOSEN, M. F. A. (Ed.). Applications of chitin and chitosan. Basel: Technomic, 1997. p. 3-29; [2]. Luciano Pighinelli, Magdalena Kucharska, Dariuz Wawro. Preparation of Microcrystalline chitosan: (MCCh0/tricalcium phosphate complex with Hydroxyapatite in sponge and fibre from for hard tissue regeneration. (author)

  6. Structure and properties of microcrystalline chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Pighinelli, Luciano; Guimaraes, Fernando Machado; Paz, Luan Rios; Zanin, Gabrielle Brehm; Kmiec, Marzena; Tedesco, Felipe Melleu; Reis, Victoria Oliva dos; Silva, Matheus Machado, E-mail: lpighinelli@hotmail.com [Universidade Luterana, Sao Paulo, SP (Brazil); Becker, Cristiane Miotto; Zehetmeyer, Gislene; Rasia, Gisele [Centro Universitario SENAI CIMATEC, Salvador, BA (Brazil). Instituto de Engenharia de Materiais Polimericos

    2016-07-01

    Full text: The microcrystalline chitosan is a modified form of chitosan; it has been elaborated from obtaining method of chitosan salts. It is characterized by special properties of the initial chitosan such as biocompatibility, bioactivity, non-toxic, biodegradability [1]. The objective of this study is to develop a different method to obtain the microcrystalline chitosan and the following characterization of the initial chitosan and MCCh. The material was characterized by FTIR, scanning of electron microscopy, SEM, nuclear magnetic resonance, NMR, and x-ray diffraction. The results indicate that the process to obtain MCCh, did not change the structure of the initial chitosan. The MCCh shows the same functional groups of the initial chitosan. The NMR results shows the acetylated and deacetylated groups. The morphology shows a homogeneous structure of surface. The X-ray diffraction shows the reduction of the crystallinity in the MCCh, indicating a bigger amorphous structure of the MCCh. The chitosan and its derivatives are polymers with excellent properties to be used in regenerative medicine because of ensure efficiency in healing process. This polysaccharide has a great potential to develop a new generation of biomaterials that can be used in regenerative medicine and tissue engineering [2]. References: [1]. LI, Q. et al. Applications and properties of chitosan. In: GOOSEN, M. F. A. (Ed.). Applications of chitin and chitosan. Basel: Technomic, 1997. p. 3-29; [2]. Luciano Pighinelli, Magdalena Kucharska, Dariuz Wawro. Preparation of Microcrystalline chitosan: (MCCh0/tricalcium phosphate complex with Hydroxyapatite in sponge and fibre from for hard tissue regeneration. (author)

  7. STIFFNESS MODIFICATION OF COTTON IN CHITOSAN TREATMENT

    Directory of Open Access Journals (Sweden)

    CAMPOS Juan

    2017-05-01

    Full Text Available Chitosan is a biopolymer obtained from chitin, and among their most important aspects highlights its applications in a lot of industrial sectors due to its intrinsic properties, especially in the textile sector. In the last years, chitosan is widely used in the cotton and wool finishing processes due to its bond between them and its properties as an antifungical and antimicrobial properties. In this paper three different molecular weight chitosan are used in the finishing process of cotton to evaluate its influence in the surface properties modification. In order to evaluate the effect of the treatment with chitosan, flexural stiffness test is performed in warp and weft direction, and then the total value is calculated. The cotton fabric is treated with 5 g/L of different types of chitosan in an impregnation bath. This study shows the extent of surface properties modification of the cotton provided by three types of chitosan treatment. The results show that all types of chitosan modify the cotton flexural rigidity properties but the one which modifies it in a relevant manner is chitosan originated from shrimps. Chitosan, textile, flexural stiffnes, chitin, cotton.

  8. Degree of Acetylization Chitosan Gonggong Snail Shells

    Science.gov (United States)

    Horiza, H.; Iskandar, I.; Aldo, N.

    2018-04-01

    Chitosan is a polysaccharide obtained from the deacetylation of chitin, which is generally derived from crustacean animal waste and animal skins other sea. One marine animals that have compounds that can be processed chitin chitosan is derived from the snail Gonggong marine waters of Riau Islands province. The purpose of this study was to determine the degree of chitosan from the shells of snails asetilisasi Gonggong. This research is an experimental research laboratory. The results of this study indicate that the degree of chitosan shell snail deasetilisasi Gonggong is 70.27%.

  9. Comparison of cadmium adsorption onto chitosan and epichlorohydrin crosslinked chitosan/eggshell composite

    Science.gov (United States)

    Rahmi; Marlina; Nisfayati

    2018-05-01

    The use of chitosan and epichlorohydrin crosslinked chitosan/eggshell composite for cadmium adsorption from water were investigated. The factors affecting adsorption such as pH and contact time were considered. The results showed that the optimum pH of adsorption was pH = 6.0 and the equilibrium time of adsorption was 40 min. The adsorption isotherm of Cd ions onto chitosan and composite were well fitted to Langmuir equation. The maximum adsorption capacity (fitting by Langmuir model) of chitosan and composite were 1.008 and 11.7647 mg/g, respectively. Adsorption performance of composite after regeneration was better than chitosan.

  10. Megalin-mediated specific uptake of chitosan/siRNA nanoparticles in mouse kidney proximal tubule epithelial cells enables AQP1 gene silencing.

    Science.gov (United States)

    Gao, Shan; Hein, San; Dagnæs-Hansen, Frederik; Weyer, Kathrin; Yang, Chuanxu; Nielsen, Rikke; Christensen, Erik I; Fenton, Robert A; Kjems, Jørgen

    2014-01-01

    RNAi-based strategies provide a great therapeutic potential for treatment of various human diseases including kidney disorders, but face the challenge of in vivo delivery and specific targeting. The chitosan delivery system has previously been shown to target siRNA specifically to the kidneys in mice when administered intravenously. Here we confirm by 2D and 3D bioimaging that chitosan formulated siRNA is retained in the kidney for more than 48 hours where it accumulates in proximal tubule epithelial cells (PTECs), a process that was strongly dependent on the molecular weight of chitosan. Chitosan/siRNA nanoparticles, administered to chimeric mice with conditional knockout of the megalin gene, distributed almost exclusively in cells that expressed megalin, implying that the chitosan/siRNA particle uptake was mediated by a megalin-dependent endocytotic pathway. Knockdown of the water channel aquaporin 1 (AQP1) by up to 50% in PTECs was achieved utilizing the systemic i.v. delivery of chitosan/AQP1 siRNA in mice. In conclusion, specific targeting PTECs with the chitosan nanoparticle system may prove to be a useful strategy for knockdown of specific genes in PTECs, and provides a potential therapeutic strategy for treating various kidney diseases.

  11. Efficient gene delivery using chitosan-polyethylenimine hybrid systems

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Hu-Lin; Kim, Tae-Hee; Kim, You-Kyoung; Park, In-Young; Cho, Chong-Su [Department of Agricultural Bioechnology, Seoul National University, Seoul 151-921 (Korea, Republic of); Cho, Myung-Haing [Laboratory of Toxicology, College of Veterinary Medicine, Seoul National University, Seoul 151-742 (Korea, Republic of)], E-mail: chocs@plaza.snu.ac.kr

    2008-06-01

    Chitosan and chitosan derivatives have been investigated as non-viral vectors because they have several advantages, such as biocompatibility, biodegradability, low cytotoxicity and low immunogenicity. However, low transfection efficiency and low cell specificity must be solved for their use in clinical trials. In this paper, chitosan-polyethylenimine (PEI) hybrid systems such as chitosan/PEI blend and chitosan-graft-PEI are described for efficient gene delivery because the PEI has high transfection efficiency owing to a proton sponge effect and chitosan has biocompatibility. Also, hepatocyte specificity of the galactosylated chitosan is explained after combination with PEI.

  12. Efficient gene delivery using chitosan-polyethylenimine hybrid systems

    International Nuclear Information System (INIS)

    Jiang, Hu-Lin; Kim, Tae-Hee; Kim, You-Kyoung; Park, In-Young; Cho, Chong-Su; Cho, Myung-Haing

    2008-01-01

    Chitosan and chitosan derivatives have been investigated as non-viral vectors because they have several advantages, such as biocompatibility, biodegradability, low cytotoxicity and low immunogenicity. However, low transfection efficiency and low cell specificity must be solved for their use in clinical trials. In this paper, chitosan-polyethylenimine (PEI) hybrid systems such as chitosan/PEI blend and chitosan-graft-PEI are described for efficient gene delivery because the PEI has high transfection efficiency owing to a proton sponge effect and chitosan has biocompatibility. Also, hepatocyte specificity of the galactosylated chitosan is explained after combination with PEI

  13. Chitosan patterning on titanium alloys

    OpenAIRE

    Gilabert Chirivella, Eduardo; Pérez Feito, Ricardo; Ribeiro, Clarisse; Ribeiro, Sylvie; Correia, Daniela; González Martin, María Luisa; Manero Planella, José María; Lanceros Méndez, Senentxu; Gallego Ferrer, Gloria; Gómez Ribelles, José Luis

    2017-01-01

    Titanium and its alloys are widely used in medical implants because of their excellent properties. However, bacterial infection is a frequent cause of titanium-based implant failure and also compromises its osseointegration. In this study, we report a new simple method of providing titanium surfaces with antibacterial properties by alternating antibacterial chitosan domains with titanium domains in the micrometric scale. Surface microgrooves were etched on pure titanium disks at i...

  14. Pseudo-thermosetting chitosan hydrogels for biomedical application.

    Science.gov (United States)

    Berger, J; Reist, M; Chenite, A; Felt-Baeyens, O; Mayer, J M; Gurny, R

    2005-01-06

    To prepare transparent chitosan/beta-glycerophosphate (betaGP) pseudo-thermosetting hydrogels, the deacetylation degree (DD) of chitosan has been modified by reacetylation with acetic anhydride. Two methods (I and II) of reacetylation have been compared and have shown that the use of previously filtered chitosan, dilution of acetic anhydride and reduction of temperature in method II improves efficiency and reproducibility. Chitosans with DD ranging from 35.0 to 83.2% have been prepared according to method II under homogeneous and non-homogeneous reacetylation conditions and the turbidity of chitosan/betaGP hydrogels containing homogeneously or non-homogeneously reacetylated chitosan has been investigated. Turbidity is shown to be modulated by the DD of chitosan and by the homogeneity of the medium during reacetylation, which influences the distribution mode of the chitosan monomers. The preparation of transparent chitosan/betaGP hydrogels requires a homogeneously reacetylated chitosan with a DD between 35 and 50%.

  15. 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 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. PMID:26927152

  16. 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.

  17. Application of irradiated chitosan for fruit preservation

    Energy Technology Data Exchange (ETDEWEB)

    Kieu N. Lan [Post Harvest Technology Inst. of Vietnam (Viet Nam)

    2000-09-01

    Application of irradiated chitosan has been investigated for coating of fruit preservation. Anti-fungal activity of chitosan was induced by {gamma}-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)

  18. Preparation and characterisation of chitosan from Penicillium ...

    African Journals Online (AJOL)

    This work investigated the removal efficiency of Congo red dye (CRD) from aqueous solution using chitosan prepared from the biomass of Penicillium chrysogenum Thom. CRD is a benzidine - based anionic diazo dye known to be carcinogenic at low concentration. Chitosan was prepared from the mycelium of P.

  19. Degradation of chitosan for rice crops application

    International Nuclear Information System (INIS)

    Norzita Yacob; Maznah Mahmud; Norhashidah Talip; Kamaruddin Hashim; Abdul Rahim Harun; Khairul Zaman; Hj Dahlan

    2013-01-01

    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)

  20. Application of irradiated chitosan for fruit preservation

    International Nuclear Information System (INIS)

    Kieu N, Lan; Nguyen D, Lam; Yoshii, Fumio; Kume, Tamikazu

    2000-01-01

    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)

  1. Preparation and characterization of magnetic chitosan particles for hyperthermia application

    International Nuclear Information System (INIS)

    Park, Ji-Ho; Im, Ki-Hyeong; Lee, Se-Ho; Kim, Dong-Hyun; Lee, Doug-Youn; Lee, Yong-Keun; Kim, Kwang-Mahn; Kim, Kyoung-Nam

    2005-01-01

    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

  2. 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.

  3. Humidity detection using chitosan film based sensor

    Science.gov (United States)

    Nasution, T. I.; Nainggolan, I.; Dalimunthe, D.; Balyan, M.; Cuana, R.; Khanifah, S.

    2018-02-01

    A humidity sensor made of the natural polymer chitosan has been successfully fabricated in the film form by a solution casting method. Humidity testing was performed by placing a chitosan film sensor in a cooling machine room, model KT-2000 Ahu. The testing results showed that the output voltage values of chitosan film sensor increased with the increase in humidity percentage. For the increase in humidity percentage from 30 to 90% showed that the output voltage of chitosan film sensor increased from 32.19 to 138.75 mV. It was also found that the sensor evidenced good repeatability and stability during the testing. Therefore, chitosan has a great potential to be used as new sensing material for the humidity detection of which was cheaper and environmentally friendly.

  4. Transfection efficiency of chitosan and thiolated chitosan in retinal pigment epithelium cells: A comparative study

    Directory of Open Access Journals (Sweden)

    Ana V Oliveira

    2013-01-01

    Full Text Available Objective: Gene therapy relies on efficient vector for a therapeutic effect. Efficient non-viral vectors are sought as an alternative to viral vectors. Chitosan, a cationic polymer, has been studied for its gene delivery potential. In this work, disulfide bond containing groups were covalently added to chitosan to improve the transfection efficiency. These bonds can be cleaved by cytoplasmic glutathione, thus, releasing the DNA load more efficiently. Materials and Methods: Chitosan and thiolated chitosan nanoparticles (NPs were prepared in order to obtain a NH3 + :PO4− ratio of 5:1 and characterized for plasmid DNA complexation and release efficiency. Cytotoxicity and gene delivery studies were carried out on retinal pigment epithelial cells. Results: In this work, we show that chitosan was effectively modified to incorporate a disulfide bond. The transfection efficiency of chitosan and thiolated chitosan varied according to the cell line used, however, thiolation did not seem to significantly improve transfection efficiency. Conclusion: The apparent lack of improvement in transfection efficiency of the thiolated chitosan NPs is most likely due to its size increase and charge inversion relatively to chitosan. Therefore, for retinal cells, thiolated chitosan does not seem to constitute an efficient strategy for gene delivery.

  5. Chitosan-folate decorated carbon nanotubes for site specific lung cancer delivery.

    Science.gov (United States)

    Singh, Rahul Pratap; Sharma, Gunjan; Sonali; Singh, Sanjay; Bharti, Shreekant; Pandey, Bajarangprasad L; Koch, Biplob; Muthu, Madaswamy S

    2017-08-01

    The aim of this work was to formulate chitosan-folate conjugated multi-walled carbon nanotubes for the lung cancer targeted delivery of docetaxel. The chitosan-folate conjugate was synthesized and the conjugation was confirmed by Fourier transform infrared spectroscopy. The multi-walled carbon nanotubes were characterized for their particle size, polydispersity, zeta potential, surface morphology, drug encapsulation efficiency and in vitro release study. The in vitro cellular uptake, cytotoxicity, and cell cycle analysis of the docetaxel/coumarin-6 loaded multi-walled carbon nanotubes were carried out to compare the effectiveness of the formulations. The biocompatibility and safety of chitosan-folate conjugated multi-walled carbon nanotubes was analyzed by lung histopathology in comparison with marketed docetaxel formulation (Docel™) and acylated multi-walled carbon nanotubes. The cellular internalization study shown that the chitosan-folate conjugated multi-walled carbon nanotubes could be easily internalized into the lung cancer cells through a folate receptor-mediated endocytic pathway. The IC 50 values exhibited that chitosan-folate conjugated multi-walled carbon nanotubes could be 89-fold more effective than Docel™ in human lung cancer cells (A549 cells). Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Oral Vaccination Based on DNA-Chitosan Nanoparticles against Schistosoma mansoni Infection

    Directory of Open Access Journals (Sweden)

    Carolina R. Oliveira

    2012-01-01

    Full Text Available The development of a vaccine would be essential for the control of schistosomiasis, which is recognized as the most important human helminth infection in terms of morbidity and mortality. A new approach of oral vaccination with DNA-chitosan nanoparticles appears interesting because of their great stability and the ease of target accessibility, besides chitosan immunostimulatory properties. Here we described that chitosan nanoparticles loaded with plasmid DNA encoding Rho1-GTPase protein of Schistosoma mansoni, prepared at different molar ratios of primary amines to DNA phosphate anion (N/P, were able to complex electrostatically with DNA and condense it into positively charged nanostructures. Nanoparticles were able to maintain zeta potential and size characteristics in media that simulate gastric (SGF and intestinal fluids (SIF. Further in vivo studies showed that oral immunization was not able to induce high levels of specific antibodies but induced high levels of the modulatory cytokine IL-10. This resulted in a significative reduce of liver pathology, although it could not protect mice of infection challenge with S. mansoni worms. Mice immunized only with chitosan nanoparticles presented 47% of protection against parasite infection, suggesting an important role of chitosan in inducing a protective immune response against schistosomiasis, which will be more explored in further studies.

  7. Controlled local drug delivery strategies from chitosan hydrogels for wound healing.

    Science.gov (United States)

    Elviri, Lisa; Bianchera, Annalisa; Bergonzi, Carlo; Bettini, Ruggero

    2017-07-01

    The main target of tissue engineering is the preparation and application of adequate materials for the design and production of scaffolds, that possess properties promoting cell adhesion, proliferation and differentiation. The use of natural polysaccharides, such as chitosan, to prepare hydrogels for wound healing and controlled drug delivery is a research topic of wide and increasing interest. Areas covered: This review presents the latest results and challenges in the preparation of chitosan and chitosan-based scaffold/hydrogel for wound healing applications. A detailed overview of their behavior in terms of controlled drug delivery, divided by drug categories, and efficacy was provided and critically discussed. Expert opinion: The need to establish and exploit the advantages of natural biomaterials in combination with active compounds is playing a pivotal role in the regenerative medicine fields. The challenges posed by the many variables affecting tissue repair and regeneration need to be standardized and adhere to recognized guidelines to improve the quality of evidence in the wound healing process. Currently, different methodologies are followed to prepare innovative scaffold formulations and structures. Innovative technologies such as 3D printing or bio-electrospray are promising to create chitosan-based scaffolds with finely controlled structures with customizable shape porosity and thickness. Chitosan scaffolds could be designed in combination with a variety of polysaccharides or active compounds with selected and reproducible spacial distribution, providing active wound dressing with highly tunable controlled drug delivery.

  8. Delivery of chitosan/dsRNA nanoparticles for silencing of wing development vestigial (vg) gene in Aedes aegypti mosquitoes.

    Science.gov (United States)

    Ramesh Kumar, D; Saravana Kumar, P; Gandhi, M Rajiv; Al-Dhabi, Naif Abdullah; Paulraj, M Gabriel; Ignacimuthu, S

    2016-05-01

    RNA interference (RNAi) has been used as a gene silencing strategy by the introduction of long double stranded RNA (dsRNA) for the control of pest insects. The aim of the present study was to examine whether the expression of vg gene which is responsible for wing development, can be repressed by chitosan/dsRNA based nanoparticles in Aedes aegypti. The vestigial gene (vg) was amplified from adult mosquito and cloned in pLitmus28i vector. Genetically engineered recombinant plasmid was transformed into RNase III deficient strain for synthesis of bacterially expressed dsRNA. Nanoparticles were prepared via electrostatic interaction between cationic polymer chitosan and anionic nucleic acids (dsRNA). The formation of chitosan/dsRNAnanoparticles and their size were confirmed by Atomic force microscopy (AFM). Chitosan/dsRNA mediated knockdown of Enhanced Green Fluorescence Protein (EGFP) was demonstrated in Sf21 cells. Further, we tested whether such an approach could be used to target vg gene in Ae. aegypti. The results showed that chitosan/dsRNA caused significant mortality, delayed growth development and caused adult wing-malformation. A qRT-PCR analysis confirmed that the chitosan/dsRNA mediated transcriptional level was downregulated. Our findings suggest that vg gene intervention strategies through RNAi can emerge as viable option for pest control. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Synthesis and characterization of a biocompatible chitosan-based hydrogel cross-linked via 'click' chemistry for controlled drug release.

    Science.gov (United States)

    Guaresti, O; García-Astrain, C; Palomares, T; Alonso-Varona, A; Eceiza, A; Gabilondo, N

    2017-09-01

    A chemically cross-linked chitosan-based hydrogel was successfully synthesized through Diels-Alder (DA) reaction and characterized. The final product was obtained after different steps; on the one hand, furan-modified chitosan (Cs-Fu) was synthesized by the reaction of furfural with the free amino groups of chitosan. On the other hand, highlighting the novelty of the present research, maleimide-functionalized chitosan (Cs-AMI) was prepared by the reaction of a maleimide-modified aminoacid with the amino groups of chitosan through amide coupling. The two complementary chitosan derivatives were cross-linked to the final hydrogel network. Both modification reactions were confirmed by FTIR and 1 H NMR, obtaining a degree of substitution (DS) of 31% and 26% for Cs-Fu and Cs-AMI, respectively. The as-designed hydrogel was analyzed in terms of microstructure, swelling capacity and rheological behaviour. The hydrogel showed pH-sensitivity, biocompatibility and inhibitory bacterial activity, promising features for biomedical applications, particularly for targeted-drug delivery. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. 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

    2016-02-27

    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 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.

  11. Green synthesis approach: extraction of chitosan from fungus mycelia.

    Science.gov (United States)

    Dhillon, Gurpreet Singh; Kaur, Surinder; Brar, Satinder Kaur; Verma, Mausam

    2013-12-01

    Chitosan, copolymer of glucosamine and N-acetyl glucosamine is mainly derived from chitin, which is present in cell walls of crustaceans and some other microorganisms, such as fungi. Chitosan is emerging as an important biopolymer having a broad range of applications in different fields. On a commercial scale, chitosan is mainly obtained from crustacean shells rather than from the fungal sources. The methods used for extraction of chitosan are laden with many disadvantages. Alternative options of producing chitosan from fungal biomass exist, in fact with superior physico-chemical properties. Researchers around the globe are attempting to commercialize chitosan production and extraction from fungal sources. Chitosan extracted from fungal sources has the potential to completely replace crustacean-derived chitosan. In this context, the present review discusses the potential of fungal biomass resulting from various biotechnological industries or grown on negative/low cost agricultural and industrial wastes and their by-products as an inexpensive source of chitosan. Biologically derived fungal chitosan offers promising advantages over the chitosan obtained from crustacean shells with respect to different physico-chemical attributes. The different aspects of fungal chitosan extraction methods and various parameters having an effect on the yield of chitosan are discussed in detail. This review also deals with essential attributes of chitosan for high value-added applications in different fields.

  12. Influence of chitosan concentration on mechanical and barrier properties of corn starch/chitosan films.

    Science.gov (United States)

    Ren, Lili; Yan, Xiaoxia; Zhou, Jiang; Tong, Jin; Su, Xingguang

    2017-12-01

    The active packaging films based on corn starch and chitosan were prepared through mixing the starch solution and the chitosan solution (1:1) by casting. The aim of this work was to characterize and analyze the effects of the chitosan concentrations (0, 21, 41, 61 and 81wt% of starch) on physicochemical, mechanical and water vapor barrier properties as well as morphological characteristics of the corn starch/chitosan (CS/CH) films. Starch molecules and chitosan could interact through hydrogen bonding as confirmed from the shift of the main peaks to higher wavenumbers in FTIR and the reduction of crystallinity in XRD. Results showed that the incorporation of chitosan resulted in an increase in film solubility, total color differences, tensile strength and elongation at break and a decrease in Young's modulus and water vapor permeability (WVP). Elongation at break of the CS/CH films increased with increasing of chitosan concentration, and reached a maximum at 41 wt%, then declined at higher chitosan concentration. The WVP of CS/CH films increased with an increase of chitosan concentration and the same tendency observed for the moisture content. The results suggest that this biodegradable CS/CH films could potentially be used as active packaging films for food and pharmaceutical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. 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.

  14. nanocomposites chitosan /clay for electrochemical sensors

    International Nuclear Information System (INIS)

    Braga, Carla R. Costa; Melo, Frank M. Araujo de; Costa, Gilmara M. Silva; Silva, Suedina M. Lima

    2009-01-01

    This study was performed to obtain films of nanocomposites chitosan/bentonite and chitosan/montmorillonite intercalation by the technique of solution in the proportions of 5:1 and 10:1. The nanocomposites were characterized by infrared spectroscopy (FTIR), X-ray diffraction (XRD) and the nanocomposites Chitosan/montmorillonite also were characterized by thermogravimetric analysis (TG). The results indicated that the feasibility of obtaining films of nanocomposites exfoliate. Among the suggested applications for films developed in this study includes them use for electrochemical sensors. (author)

  15. Viscometric studies of chitosan radiation degradation

    International Nuclear Information System (INIS)

    Rapado, M.; Ceausoglu, I.; Hunkeler, D.

    2001-01-01

    The paper presents the preliminary results, related to the viscometric studies on chitosan gamma radiation degradation. To follow the effects on the processes of chitosan transformations caused by irradiation in vacuum irradiated solutions changes of viscosity, and viscosity average molecular weight were measured The influence of absorbed dose on the chitosan molecular weight was studied using the Mark-Houwink-Sakurada equation. Various relationships for the for the determination of the intrinsic viscosity were made vias the Huggins, Kramer and Schulz- Blaschke models. The distinct decrease of intrinsic viscosity indicates that the main change scission was the dominating process

  16. Rheological study of chitosan in solution

    International Nuclear Information System (INIS)

    Silva, Italo Guimaraes Medeiros da; Alves, Keila dos Santos; Balaban, Rosangela de Carvalho

    2009-01-01

    Chitosan is an abundant biopolymer with remarkable physicochemical and biological properties, usually employed in a wide range of applications. It acts as a cationic polyelectrolyte in aqueous acid solutions, leading to unique characteristics. In this work, chitosan was characterized by 1 H NMR and its rheological behavior were studied as function of chitosan sample, shear rate, polymer concentration, ionic strength, time and temperature. In order to calculate rheological parameters and to understand the macromolecular dynamic in solution, the Otswald-de Waele model was fitted. (author)

  17. Functionalization of chitosan by click chemistry

    Science.gov (United States)

    Cheaburu-Yilmaz, Catalina Natalia; Karavana, Sinem Yaprak; Yilmaz, Onur

    2017-12-01

    Chitosan modification represents a challenge nowadays. The variety of compounds which can be obtained with various architectures and different functionalities made it attractive to be used in fields like pharmacy and material science. Presents study deals with the chemical modification of chitosan by using click chemistry technique. The study adopted the approach of clicking azidated chitosan with a synthesized alkyne terminated polymer i.e. poly N isopropylacrylamide with thermoresponsive properties. Structures were confirmed by the FT-IR and HNMR spectra. Thermal characterization was performed showing different thermal behaviour with the chemical modification. The final synthesized graft copolymer can play important role within pharmaceutical formulations carrying drugs for topical or oral treatments.

  18. Some features of irradiated chitosan and its biological effect

    Energy Technology Data Exchange (ETDEWEB)

    Hai, Le; Hien, Nguyen Quoc; Luan, Le Quang; Hanh, Truong Thi; Man, Nguyen Tan; Ha, Pham Thi Le; Thuy, Tran Thi [Nuclear Research Institute, VAEC, Dalat (Viet Nam); Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2001-03-01

    Preparation of chitosan oligomer by radiation degradation was carried out on the gamma Co-60 source. The radiation degradation yield (G{sub d}) of the chitosan was found to be of 1.03. The oligochitosan with 50% of dp>8 fraction was obtained by irradiating the 10% (w/v) chitosan solution in 5% acetic acid at 45 kGy for the chitosan having the initial viscometric average molecular weight, Mv=60,000. Irradiated chitosan showed higher antifungal effect than that of unirradiated one. Furthermore, the irradiated chitosan also showed the growth-promotion effect for plants. (author)

  19. Some features of irradiated chitosan and its biological effect

    International Nuclear Information System (INIS)

    Hai, Le; Hien, Nguyen Quoc; Luan, Le Quang; Hanh, Truong Thi; Man, Nguyen Tan; Ha, Pham Thi Le; Thuy, Tran Thi; Yoshii, Fumio; Kume, Tamikazu

    2001-01-01

    Preparation of chitosan oligomer by radiation degradation was carried out on the gamma Co-60 source. The radiation degradation yield (G d ) of the chitosan was found to be of 1.03. The oligochitosan with 50% of dp>8 fraction was obtained by irradiating the 10% (w/v) chitosan solution in 5% acetic acid at 45 kGy for the chitosan having the initial viscometric average molecular weight, Mv=60,000. Irradiated chitosan showed higher antifungal effect than that of unirradiated one. Furthermore, the irradiated chitosan also showed the growth-promotion effect for plants. (author)

  20. Synthesis of Glycyrrhetinic Acid-Modified Chitosan 5-Fluorouracil Nanoparticles and Its Inhibition of Liver Cancer Characteristics in Vitro and in Vivo

    OpenAIRE

    Cheng, Mingrong; Gao, Xiaoyan; Wang, Yong; Chen, Houxiang; He, Bing; Xu, Hongzhi; Li, Yingchun; Han, Jiang; Zhang, Zhiping

    2013-01-01

    Nanoparticle drug delivery (NDDS) is a novel system in which the drugs are delivered to the site of action by small particles in the nanometer range. Natural or synthetic polymers are used as vectors in NDDS, as they provide targeted, sustained release and biodegradability. Here, we used the chitosan and hepatoma cell-specific binding molecule, glycyrrhetinic acid (GA), to synthesize glycyrrhetinic acid-modified chitosan (GA-CTS). The synthetic product was confirmed by Fourier transformed inf...

  1. Biocompatibility of chitosan-coated iron oxide nanoparticles with osteoblast cells

    Directory of Open Access Journals (Sweden)

    Shi S

    2012-10-01

    Full Text Available Si-Feng Shi,1 Jing-Fu Jia,2 Xiao-Kui Guo,3 Ya-Ping Zhao,2 De-Sheng Chen,1 Yong-Yuan Guo,1 Tao Cheng,1 Xian-Long Zhang11Department of Orthopedic Surgery, Shanghai Sixth People’s Hospital, School of Medicine, 2School of Chemistry and Chemical Technology, 3Department of Medical Microbiology and Parasitology, School of Medicine, Shanghai Jiao Tong University Shanghai, ChinaBackground: Bone disorders (including osteoporosis, loosening of a prosthesis, and bone infections are of great concern to the medical community and are difficult to cure. Therapies are available to treat such diseases, but all have drawbacks and are not specifically targeted to the site of disease. Chitosan is widely used in the biomedical community, including for orthopedic applications. The aim of the present study was to coat chitosan onto iron oxide nanoparticles and to determine its effect on the proliferation and differentiation of osteoblasts.Methods: Nanoparticles were characterized using transmission electron microscopy, dynamic light scattering, x-ray diffraction, zeta potential, and vibrating sample magnetometry. Uptake of nanoparticles by osteoblasts was studied by transmission electron microscopy and Prussian blue staining. Viability and proliferation of osteoblasts were measured in the presence of uncoated iron oxide magnetic nanoparticles or those coated with chitosan. Lactate dehydrogenase, alkaline phosphatase, total protein synthesis, and extracellular calcium deposition was studied in the presence of the nanoparticles.Results: Chitosan-coated iron oxide nanoparticles enhanced osteoblast proliferation, decreased cell membrane damage, and promoted cell differentiation, as indicated by an increase in alkaline phosphatase and extracellular calcium deposition. Chitosan-coated iron oxide nanoparticles showed good compatibility with osteoblasts.Conclusion: Further research is necessary to optimize magnetic nanoparticles for the treatment of bone disease

  2. Progress of research on the adsorption of chitosan and its derivatives to uranium

    International Nuclear Information System (INIS)

    Wang Caixia; Liu Yunhai; Hua Rong; Pang Cui; Wang Yong

    2010-01-01

    This paper has summarized the study on the adsorption of chitosan and its derivatives to uranium in recent years at home and abroad. It was found that the derivatives can be serine-type chitosan, methyl phosphoric acid modified chitosan, 3,4-dihydroxy benzoic acid-type chitosan, chitosan with 3,4-dihydroxybenzoic acid moiety, chitosan resin possessing a phenylarsonic acid moiety, quadrol modified chitosan, chitosan modified with molecular imprinting technique, polyacrylamide hydrogel, chitosan-coated perlite and so on. The application vista of chitosan and its derivatives to Absorpt uranium in water has been prospected. (authors)

  3. Preparation and characterisation of irradiated crab chitosan and New Zealand Arrow squid pen chitosan

    International Nuclear Information System (INIS)

    Shavandi, Amin; Bekhit, Adnan A.; Bekhit, Alaa El-Din A.; Sun, Zhifa; Ali, M. Azam

    2015-01-01

    The properties of chitosan from Arrow squid (Nototodarus sloanii) pen (CHS) and commercial crab shell (CHC) were investigated using FTIR, DSC, SEM and XRD before and after irradiation at the dose of 28 kGy in the presence or absence of 5% water. Also, the viscosity, deacetylation degree, water and oil holding capacities, colour and antimicrobial activities of the chitosan samples were determined. Irradiation decreased (P < 0.05) the viscosity of CHC from 0.21 to 0.03 Pa s and of CHS from 1.71 to 0.23 Pa s. The inclusion of water had no effect on the viscosity of irradiated chitosan. Irradiation did not affect the degree of deacetylation of CHC, but increased the deacetylation degree of CHS from 72.78 to 82.29% in samples with 5% water. Water and oil holding capacities of CHS (1197.30% and 873.3%, respectively) were higher (P < 0.05) than those found in CHC (340.70% and 264.40%, respectively). The water and oil holding capacities were decreased for both types of chitosan irradiation, but were not affected by the addition of water. Squid pen chitosan was whiter in colour (White Index = 90.06%) compared to CHC (White Index = 83.70%). Generally, the CHC samples (control and irradiated) exhibited better antibacterial activity compared to CHS, but the opposite was observed with antifungal activity. - Highlights: • Chitosan prepared from Arrow squid pens (Nototodarus sloanii). • Chitosan samples were gamma irradiated at 28 kGy. • Squid pen chitosan showed high fat and water uptake capacities compared to crab shell chitosan. • Gamma irradiation enhanced the DDA of squid pen chitosan but not crab shell chitosan.

  4. Chitosan: collagen sponges. In vitro mineralization

    International Nuclear Information System (INIS)

    Martins, Virginia da C.A.; Silva, Gustavo M.; Plepis, Ana Maria G.

    2011-01-01

    The regeneration of bone tissue is a problem that affects many people and scaffolds for bone tissue growth has been widely studied. The aim of this study was the in vitro mineralization of chitosan, chitosan:native collagen and chitosan:anionic collagen sponges. The sponges were obtained by lyophilization and mineralization was made by soaking the sponges in alternating solutions containing Ca 2+ and PO 4 3- . The mineralization was confirmed by infrared spectroscopy, energy dispersive X-ray and X-ray diffraction observing the formation of phosphate salts, possibly a carbonated hydroxyapatite since Ca/P=1.80. The degree of mineralization was obtained by thermogravimetry calculating the amount of residue at 750 deg C. The chitosan:anionic collagen sponge showed the highest degree of mineralization probably due to the fact that anionic collagen provides additional sites for interaction with the inorganic phase. (author)

  5. Optimization of electrospinning parameters for chitosan nanofibres

    CSIR Research Space (South Africa)

    Jacobs, V

    2011-06-01

    Full Text Available Electrospinning of chitosan, a naturally occurring polysaccharide biopolymer, has been investigated. In this paper, the authors report the optimization of electrospinning process and solution parameters using factorial design approach to obtain...

  6. Electrochemical and Thermal Studies of Prepared Conducting Chitosan Biopolymer Film

    International Nuclear Information System (INIS)

    Hlaing Hlaing Oo; Kyaw Naing; Kyaw Myo Naing; Tin Tin Aye; Nyunt Wynn

    2005-09-01

    In this paper, chitosan based conducting bipolymer films were prepared by casting and solvent evaporating technique. All prepared chitosan films were of pale yellow colour, transparent, and smooth. Sulphuric acid was chosen as the cross-linking agent. It enhanced conduction pathway in cross-linked chitosan films. Mechanical properties, solid-state, and thermal behavior of prepared chitosan fimls were studied by means of a material testing machine, powder X-ray diffractometry (XRD), thermogravimetric analysis (TG-DTG), and differential scanning calorimetry (DSC). By the XRD diffraction pattern, high molecular weight of chitosan product indicates the semi-crystalline nature, but the prepared chitosan film and doped chitosan film indicate significantly lower in crystallinity prove which of the amorphous characteristics. In addition, DSC thermogram of pure chitosan film exhibited exothermic peak around at 300 C, indicating polymer decomposition of chitosan molecules in chitosan films. Furthermore, these DSC thermograms clearly showed that while pure chitosan film display exothermal decomposition, the doped chitosan films mainly endothermic characteristics. The ionic conductivity of doped chitosan films were in the order of 10 to 10 S cm , which is in the range of semi-conductor. These results showed that cross-linked chitoson films may be used as polymer electrolyte film to fabricate solid state electrochemical cells

  7. Aerogels from Chitosan Solutions in Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Gonzalo Santos-López

    2017-12-01

    Full Text Available Chitosan aerogels conjugates the characteristics of nanostructured porous materials, i.e., extended specific surface area and nano scale porosity, with the remarkable functional properties of chitosan. Aerogels were obtained from solutions of chitosan in ionic liquids (ILs, 1-butyl-3-methylimidazolium acetate (BMIMAc, and 1-ethyl-3-methyl-imidazolium acetate (EMIMAc, in order to observe the effect of the solvent in the structural characteristics of this type of materials. The process of elaboration of aerogels comprised the formation of physical gels through anti-solvent vapor diffusion, liquid phase exchange, and supercritical CO2 drying. The aerogels maintained the chemical identity of chitosan according to Fourier transform infrared spectrophotometer (FT-IR spectroscopy, indicating the presence of their characteristic functional groups. The internal structure of the obtained aerogels appears as porous aggregated networks in microscopy images. The obtained materials have specific surface areas over 350 m2/g and can be considered mesoporous. According to swelling experiments, the chitosan aerogels could absorb between three and six times their weight of water. However, the swelling and diffusion coefficient decreased at higher temperatures. The structural characteristics of chitosan aerogels that are obtained from ionic liquids are distinctive and could be related to solvation dynamic at the initial state.

  8. Effect of Chitosan Properties on Immunoreactivity

    Directory of Open Access Journals (Sweden)

    Sruthi Ravindranathan

    2016-05-01

    Full Text Available 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 from various sources were treated with mouse and human APCs (macrophages and/or dendritic cells and the amount of tumor necrosis factor-α (TNF-α released by the cells was used as an indicator of immunoreactivity. Our results indicate that only endotoxin content and not DDA or viscosity influenced chitosan-induced immune responses. Our data also indicate that low endotoxin chitosan (<0.01 EU/mg ranging from 20 to 600 cP and 80% to 97% DDA is essentially inert. This study emphasizes the need for more complete characterization and purification of chitosan in preclinical studies in order for this valuable biomaterial to achieve widespread clinical application.

  9. Photocrosslinkable chitosan as a biological adhesive.

    Science.gov (United States)

    Ono, K; Saito, Y; Yura, H; Ishikawa, K; Kurita, A; Akaike, T; Ishihara, M

    2000-02-01

    A photocrosslinkable chitosan to which both azide and lactose moieties were introduced (Az-CH-LA) was prepared as a biological adhesive for soft tissues and its effectiveness was compared with that of fibrin glue. Introduction of the lactose moieties resulted in a much more water-soluble chitosan at neutral pH. Application of ultraviolet light (UV) irradiation to photocrosslinkable Az-CH-LA produced an insoluble hydrogel within 60 s. This hydrogel firmly adhered two pieces of sliced ham with each other, depending upon the Az-CH-LA concentration. The binding strength of the chitosan hydrogel prepared from 30-50 mg/mL of Az-CH-LA was similar to that of fibrin glue. Compared to the fibrin glue, the chitosan hydrogel more effectively sealed air leakage from pinholes on isolated small intestine and aorta and from incisions on isolated trachea. Neither Az-CH-LA nor its hydrogel showed any cytotoxicity in cell culture tests of human skin fibroblasts, coronary endothelial cells, and smooth muscle cells. Furthermore, all mice studied survived for at least 1 month after implantation of 200 microL of photocrosslinked chitosan gel and intraperitoneal administration of up to 1 mL of 30 mg/mL of Az-CH-LA solution. These results suggest that the photocrosslinkable chitosan developed here has the potential of serving as a new tissue adhesive in medical use. Copyright 2000 John Wiley & Sons, Inc.

  10. Oxidation-mediated chitosan as additives for creation of chitosan aerogels with diverse three-dimensional interconnected skeletons

    International Nuclear Information System (INIS)

    Zhang, Sizhao; Feng, Jian; Feng, Junzong; Jiang, Yonggang

    2017-01-01

    Highlights: • A new synthetic method for controlling morphology of chitosan aerogels is proposed. • Chitosan aerogels with nanoflake-like and nanofiber-like were prepared. • Textures of chitosan aerogels are strongly dependent upon the oxidation pattern. - Abstract: Naturally occurring polymer-based aerogels have myriad practical utilizations due to environmentally benign and fruitful resources. However, engineering morphology-controllable biomass aerogels still represents a great challenge. Here we present a facile solution to synthesize chitosan aerogels having distinguished textures by reacting oxidized chitosan with formaldehyde and chitosan sol. In more detail, chitosan was chemically oxidized using two types of oxidation agents such as ammonium persulphate (SPD) and sodium periodate (APS) to obtain corresponding oxidized chitosan, subsequently cross-linked with chitosan solution containing formaldehyde to harvest SPD-oxidized chitosan aerogels (SCAs) and APS-SPD-oxidized ones (ASCAs) after aging, solvent exchange and supercritical drying processes. We found that the morphologies of as-prepared chitosan aerogels are strongly dependent upon the oxidation pattern towards chitosan. The structural textures of SCAs and ASCAs appear nanoflake-like and nanofiber-like structures, which may be related to spatial freedom of active groups located in chitosan. Selected area electron diffraction analysis reveals that the crystalline properties of chitosan aerogels generally appear the serious deterioration comparing to raw chitosan owing to their interconnected skeletal structure formation. The occurrence of characteristic groups displays cross-linked chain construction by using chemical state measurements such as FT-IR and XPS. Further, a plausible mechanism for controlling morphology of chitosan aerogels is also established. This new family of method for creation of chitosan aerogels may open up a perspective for biomass aerogels with controllable textures.

  11. Oxidation-mediated chitosan as additives for creation of chitosan aerogels with diverse three-dimensional interconnected skeletons

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Sizhao, E-mail: bule-soul@hotmail.com; Feng, Jian, E-mail: fengj@nudt.edu.cn; Feng, Junzong; Jiang, Yonggang

    2017-02-28

    Highlights: • A new synthetic method for controlling morphology of chitosan aerogels is proposed. • Chitosan aerogels with nanoflake-like and nanofiber-like were prepared. • Textures of chitosan aerogels are strongly dependent upon the oxidation pattern. - Abstract: Naturally occurring polymer-based aerogels have myriad practical utilizations due to environmentally benign and fruitful resources. However, engineering morphology-controllable biomass aerogels still represents a great challenge. Here we present a facile solution to synthesize chitosan aerogels having distinguished textures by reacting oxidized chitosan with formaldehyde and chitosan sol. In more detail, chitosan was chemically oxidized using two types of oxidation agents such as ammonium persulphate (SPD) and sodium periodate (APS) to obtain corresponding oxidized chitosan, subsequently cross-linked with chitosan solution containing formaldehyde to harvest SPD-oxidized chitosan aerogels (SCAs) and APS-SPD-oxidized ones (ASCAs) after aging, solvent exchange and supercritical drying processes. We found that the morphologies of as-prepared chitosan aerogels are strongly dependent upon the oxidation pattern towards chitosan. The structural textures of SCAs and ASCAs appear nanoflake-like and nanofiber-like structures, which may be related to spatial freedom of active groups located in chitosan. Selected area electron diffraction analysis reveals that the crystalline properties of chitosan aerogels generally appear the serious deterioration comparing to raw chitosan owing to their interconnected skeletal structure formation. The occurrence of characteristic groups displays cross-linked chain construction by using chemical state measurements such as FT-IR and XPS. Further, a plausible mechanism for controlling morphology of chitosan aerogels is also established. This new family of method for creation of chitosan aerogels may open up a perspective for biomass aerogels with controllable textures.

  12. Enhancement of antimicrobial activity of chitosan by irradiation

    International Nuclear Information System (INIS)

    Matsuhashi, S.; Kume, T.

    1997-01-01

    Antimicrobial activity of irradiated chitosan was studied against Escherichia coli B/r. Irradiation of chitosan at 100 kGy under dry conditions was effective in increasing the activity, and inhibited the growth of E. coli completely. The molecular weight of chitosan significantly decreased with the increase in irradiation dose, whereas the relative surface charge of chitosan was decreased only 3% by 100 kGy irradiation. Antimicrobial activity assay of chitosan fractionated according to molecular weight showed that 1 x 10 5 -3 x 10 5 fraction was most effective in suppressing the growth of E coli. This fraction comprised only 8% of the 100 kGy irradiated chitosan. On the other hand, chitosan whose molecular weight was less than 1 x 10 5 had no activity. The results show that low dose irradiation, specifically 100 kGy, of chitosan gives enough degradation to increase its antimicrobial activity as a result of a change in molecular weight. (Author)

  13. Maillard reaction products from chitosan-xylan ionic liquid solution.

    Science.gov (United States)

    Luo, Yuqiong; Ling, Yunzhi; Wang, Xiaoying; Han, Yang; Zeng, Xianjie; Sun, Runcang

    2013-10-15

    A facile method is reported to prepare Maillard reaction products (MRPs) from chitosan and xylan in co-solvent ionic liquid. UV absorbance and fluorescence changes were regarded as indicators of the occurrence of Maillard reaction. FT-IR, NMR, XRD and TG were used to investigate the structure of chitosan-xylan conjugate. The results revealed that when chitosan reacted with xylan in ionic liquid, the hydrogen bonds in chitosan were destroyed, the facts resulted in the formation of chitosan-xylan MRPs. Moreover, when the mass ratio of chitosan to xylan was 1:1, the Maillard reaction proceeded easily. In addition, relatively high antioxidant property was also noted for the chitosan-xylan conjugate with mass ratio 1:1. So the obtained chitosan-xylan MRP is a promising antioxidant agent for food industry. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Chitosan-Coated Magnetic Nanoparticles with Low Chitosan Content Prepared in One-Step

    Directory of Open Access Journals (Sweden)

    Yolanda Osuna

    2012-01-01

    Full Text Available 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 allowed to determine that they were composed of 95 wt% of magnetic nanoparticles and 5 wt% of chitosan. 67% efficacy in the Pb+2 removal test indicated that only 60% of amino groups on CMNP surface bound to Pb, probably due to some degree of nanoparticle flocculation during the redispersion. The very low weight ratio chitosan to magnetic nanoparticles obtained in this study, 0.053, and the high yield of the precipitation reactions (≈97% are noticeable.

  15. Characterization of bioactive chitosan and sulfated chitosan from Doryteuthis singhalensis (Ortmann, 1891).

    Science.gov (United States)

    Ramasamy, Pasiyappazham; Subhapradha, Namasivayam; Thinesh, Thangadurai; Selvin, Joseph; Selvan, Kanagaraj Muthamizh; Shanmugam, Vairamani; Shanmugam, Annaian

    2017-06-01

    Chitosan was extracted from the pen of squid Doryteuthis singhalensis and characterized using FT-IR, NMR, CHN, SEM and DSC analysis. Purified chitosan was sulfated with chlorosulfonic acid in N,N-dimethylformamide and the added sulfate group was confirmed with FT-IR analysis. The molecular weight and degree of deacetylation (DDA) of chitosan was found 226.6kDa and 83.76% respectively. Chitosan exhibited potent antioxidant activity evidenced by reducing power, chelating ability on ferrous ions and scavenging activity on DPPH, superoxide and hydroxyl radicals. The anticoagulant assay using activated partial thromboplastin time (APTT) and prothrombin time (PT) showed chitosan as a strong anticoagulant. The results of this study showed possibility of using D. singhalensis pen as a non-conventional source of natural antioxidants and anticoagulant which can be incorporated in functional food formulations. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. The effect of andiroba oil and chitosan concentration on the physical properties of chitosan emulsion film

    Directory of Open Access Journals (Sweden)

    Vanessa Tiemi Kimura

    Full Text Available Abstract Chitosan film is used as a dressing to heal burns. The physical and biological properties of the film can be modified by the addition of phytotherapic compounds. This work used the casting -solvent evaporation technique to prepare chitosan film containing andiroba oil (Carapa guianensis which has anti-inflammatory, antibiotic, and healing properties. The objective of this study was to determine the effect of the concentrations of chitosan and andiroba oil on the physical properties of chitosan films. The emulsion films were evaluated concerning the mechanical properties and fluid handling capacity. Additionally, scanning electron microscopy and thermal analysis were performed. The results showed that the barrier and mechanical properties were affected by the addition of andiroba oil, and these may be modulated as a function of the concentration of oil added to the film. The thermal analysis showed no evidence of chemical interactions between the oil and chitosan.

  17. An Investigation of Chitosan for Sorption of Radionuclides

    Science.gov (United States)

    2012-06-05

    Valenta et al. found that hydrogels made of EDTA-chitsoan were resistant to bacterial growth [88]. Nishi et al. found that alka- line earth metals...reviews of chitosan deriva- tives have been recently published [8, 21, 75, 89]. 10 Table 2.1: Select applications of chitosan. From [72, 75]. Agriculture ...pharmaceuticals 2.1.3 Chitosan applications Chitosan has found applications in a wide range of fields, including agriculture , water treatment, biomedical

  18. Chitosan: An Update on Potential Biomedical and Pharmaceutical Applications

    Directory of Open Access Journals (Sweden)

    Randy Chi Fai Cheung

    2015-08-01

    Full Text Available Chitosan is a natural polycationic linear polysaccharide derived from chitin. The low solubility of chitosan in neutral and alkaline solution limits its application. Nevertheless, chemical modification into composites or hydrogels brings to it new functional properties for different applications. Chitosans are recognized as versatile biomaterials because of their non-toxicity, low allergenicity, biocompatibility and biodegradability. This review presents the recent research, trends and prospects in chitosan. Some special pharmaceutical and biomedical applications are also highlighted.

  19. Chitosan: An Update on Potential Biomedical and Pharmaceutical Applications

    Science.gov (United States)

    Cheung, Randy Chi Fai; Ng, Tzi Bun; Wong, Jack Ho; Chan, Wai Yee

    2015-01-01

    Chitosan is a natural polycationic linear polysaccharide derived from chitin. The low solubility of chitosan in neutral and alkaline solution limits its application. Nevertheless, chemical modification into composites or hydrogels brings to it new functional properties for different applications. Chitosans are recognized as versatile biomaterials because of their non-toxicity, low allergenicity, biocompatibility and biodegradability. This review presents the recent research, trends and prospects in chitosan. Some special pharmaceutical and biomedical applications are also highlighted. PMID:26287217

  20. Adhesion and viability of two enterococcal strains on covalently grafted chitosan and chitosan/kappa-carrageenan multilayers

    NARCIS (Netherlands)

    Bratskaya, S.; Marinin, D.; Simon, F.; Synytska, A.; Zschoche, S.; Busscher, H. J.; Jager, D.; van der Mei, H. C.

    Chitosans are natural aminopolysaccharides, whose low cytotoxicity suggests their potential use for nonadhesive, antibacterial coatings on biomaterials implant surfaces. Here, the antiadhesive behavior and ability to kill bacteria upon adhesion ("contact killing") of chitosan coatings were evaluated

  1. Development of Chitosan Acetate Films for Transdermal Delivery of ...

    African Journals Online (AJOL)

    Erah

    Methods: Chitosan acetate was chemically modified with acetaldehyde and the solution was prepared ... from solution [3]. In this regard possibilities for the potential use of chitosan as an absorption enhancer in the more basic environment of the large intestine, colon and ..... impregnation of ophthalmic drugs on chitosan.

  2. Interactions between chitosan and cells measured by AFM

    Energy Technology Data Exchange (ETDEWEB)

    Hsiao, Sheng-Wen; Thien, Doan Van Hong; Ho, Ming-Hua [Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10617, Taiwan (China); Hsieh, Hsyue-Jen [Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Li, Chung-Hsing [Division of Orthodontics and Pediatric Dentistry, Department of Dentistry, Tri-Service General Hospital, Taipei, Taiwan (China); Hung, Chang-Hsiang [Department of Dentistry, Kinmen Hospital Department of Health, Taiwan (China); Li, Hsi-Hsin, E-mail: mhho@mail.ntust.edu.t [Deputy Superintendent, Kinmen Hospital Department of Health, Taiwan (China)

    2010-10-01

    Chitosan, a biocompatible material that has been widely used in bone tissue engineering, is believed to have a high affinity to osteoblastic cells. This research is the first to prove this hypothesis. By using atomic force microscopy (AFM) with a chitosan-modified cantilever, quantitative evaluation of the interforce between chitosan and cells was carried out. A chitosan tip functionalized with Arg-Gly-Asp (RGD) was also used to measure the interforce between RGD-chitosan and osteoblastic cells. This research concluded by examining cell adhesion and spreading of chitosan substrates as further characterization of the interactions between cells and chitosan. The force measured by AFM showed that the interforce between chitosan and osteoblasts was the highest (209 nN). The smallest adhesion force (61.8 nN) appeared between chitosan and muscle fibroblasts, which did not demonstrate any osteoblastic properties. This result proved that there was a significant interaction between chitosan and bone cells, and correlated with the observations of cell attachment and spreading. The technique developed in this research directly quantified the adhesion between chitosan and cells. This is the first study to demonstrate that specific interaction exists between chitosan and osteoblasts.

  3. Vitamin D-fortified chitosan films from mushroom waste

    Science.gov (United States)

    Brown mushroom (Agaricus bisporus) stalk bases from mushroom waste were treated with UV-B light to rapidly increase vitamin D2 content. Chitin was also recovered from this waste and converted into chitosan by N-deacetylation. FTIR spectra showed that the mushroom chitosan were similar to chitosan fr...

  4. Interactions between chitosan and cells measured by AFM

    International Nuclear Information System (INIS)

    Hsiao, Sheng-Wen; Thien, Doan Van Hong; Ho, Ming-Hua; Hsieh, Hsyue-Jen; Li, Chung-Hsing; Hung, Chang-Hsiang; Li, Hsi-Hsin

    2010-01-01

    Chitosan, a biocompatible material that has been widely used in bone tissue engineering, is believed to have a high affinity to osteoblastic cells. This research is the first to prove this hypothesis. By using atomic force microscopy (AFM) with a chitosan-modified cantilever, quantitative evaluation of the interforce between chitosan and cells was carried out. A chitosan tip functionalized with Arg-Gly-Asp (RGD) was also used to measure the interforce between RGD-chitosan and osteoblastic cells. This research concluded by examining cell adhesion and spreading of chitosan substrates as further characterization of the interactions between cells and chitosan. The force measured by AFM showed that the interforce between chitosan and osteoblasts was the highest (209 nN). The smallest adhesion force (61.8 nN) appeared between chitosan and muscle fibroblasts, which did not demonstrate any osteoblastic properties. This result proved that there was a significant interaction between chitosan and bone cells, and correlated with the observations of cell attachment and spreading. The technique developed in this research directly quantified the adhesion between chitosan and cells. This is the first study to demonstrate that specific interaction exists between chitosan and osteoblasts.

  5. Impact of chitosan application technique on refrigerated catfish fillet quality

    Science.gov (United States)

    Chitosan has been reported to have functional properties such as antimicrobial activity, antioxidant activity, and binding action. Several studies reported an extension in the shelf life of various food products when chitosan was applied. However, there is limited study on the effect of chitosan ap...

  6. Probing cellular behaviors through nanopatterned chitosan membranes

    International Nuclear Information System (INIS)

    Yang, Chung-Yao; Sung, Chun-Yen; Shuai, Hung-Hsun; Cheng, Chao-Min; Yeh, J Andrew

    2013-01-01

    This paper describes a high-throughput method for developing physically modified chitosan membranes to probe the cellular behavior of MDCK epithelial cells and HIG-82 fibroblasts adhered onto these modified membranes. To prepare chitosan membranes with micro/nanoscaled features, we have demonstrated an easy-to-handle, facile approach that could be easily integrated with IC-based manufacturing processes with mass production potential. These physically modified chitosan membranes were observed by scanning electron microscopy to gain a better understanding of chitosan membrane surface morphology. After MDCK cells and HIG-82 fibroblasts were cultured on these modified chitosan membranes for various culture durations (i.e. 1, 2, 4, 12 and 24 h), they were investigated to decipher cellular behavior. We found that both cells preferred to adhere onto a flat surface rather than on a nanopatterned surface. However, most (> 80%) of the MDCK cells showed rounded morphology and would suspend in the cultured medium instead of adhering onto the planar surface of negatively nanopatterned chitosan membranes. This means different cell types (e.g. fibroblasts versus epithelia) showed distinct capabilities/preferences of adherence for materials of varying surface roughness. We also showed that chitosan membranes could be re-used at least nine times without significant contamination and would provide us consistency for probing cell–material interactions by permitting reuse of the same substrate. We believe these results would provide us better insight into cellular behavior, specifically, microscopic properties and characteristics of cells grown under unique, nanopatterned cell-interface conditions. (paper)

  7. Scanning electron microscopy and swelling test of shrimp shell chitosan and chitosan-RGD scaffolds

    Science.gov (United States)

    Mandacan, M. C.; Yuniastuti, M.; Amir, L. R.; Idrus, E.; Suniarti, D. F.

    2017-08-01

    Shrimp shell chitosan and chitosan-RGD scaffold membranes are produced to be biocompatible with tissue engineering. Nonetheless, their architectural properties have not yet been studied. Analyze the architectural properties of chitosan and chitosan-RGD scaffolds. Analyze pore count and size, interpore distance, and porosity (using SEM testing and ImageJ analysis) and water absorption (using a swelling test). The properties of the chitosan and chitosan-RGD scaffolds were as follows, respectively. The pore counts were 225 and 153; pore size, 171.4 μam and 180.2 μam interpore distance, 105.7 μam and 101.4 μam porosity, 22% and 10.2%; and water absorption, 9.1 mgH2O/mgScaffold and 19.3 mgH2O/mgScaffold. The shrimp shell chitosan-RGD membrane scaffold was found to have architectural properties that make it more conducive to use in tissue engineering.

  8. Extraction and Characterization of Chitin and Chitosan from Blue Crab and Synthesis of Chitosan Cryogel Scaffolds

    Directory of Open Access Journals (Sweden)

    Nimet Bölgen

    2016-08-01

    Full Text Available Polymeric scaffolds produced by cryogelation technique have attracted increasing attention for tissue engineering applications. Cryogelation is a technique which enables to produce interconnected porous matrices from the frozen reaction mixtures of polymers or monomeric precursors. Chitosan is a biocompatible, biodegradable, nontoxic, antibacterial, antioxidant and antifungal natural polymer that is obtained by deacetylation of chitin, which is mostly found in the exoskeleton of many crustacean. In this study, chitin was isolated from the exoskeleton of blue crap (Callinectes sapidus using a chemical method. Callinectes sapidus samples were collected from a market, as a waste material after it has been consumed as food. Demineralization, deproteinization and decolorization steps were applied to the samples to obtain chitin. Chitosan was prepared from isolated chitin by deacetylation at high temperatures. The chemical compositon of crab shell, extracted chitin and chitosan were characterized with FTIR analyses. And also to determine the physicochemical and functional properties of the produced chitosan; solubility, water binding and fat binding analysis were performed. Chitosan cryogel scaffolds were prepared by crosslinking reaction at cryogenic conditions at constant amount of chitosan (1%, w/v with different ratios of glutaraldehyde (1, 3, and 6%, v/v as crosslinker. The chemical structure of the scaffolds were examined by FTIR. Also, the water uptake capacity of scaffolds have been determined. Collectively, the results suggested that the characterized chitosan cryogels can be potential scaffolds to be used in tissue engineering applications.

  9. Impedance spectroscopy study of dehydrated chitosan and chitosan containing LiClO4

    International Nuclear Information System (INIS)

    Costa, M.M.; Terezo, A.J.; Matos, A.L.; Moura, W.A.; Giacometti, Jose A.; Sombra, A.S.B.

    2010-01-01

    Cast films of chitosan and chitosan containing LiClO 4 were characterized using Fourier transform infrared spectroscopy and the thermogravimetric technique. The electric properties of hydrated and dehydrated films were investigated with impedance spectroscopy in the frequency range from 0.1 Hz to 1 MHz, at temperatures varying from 30 to 110 o C. The frequency dependence of the impedance for dehydrated chitosan and chitosan containing LiClO 4 films indicated ionic conduction. Two relaxation peaks were evident on the imaginary curve of the electric modulus, which were assigned to ionic conduction. The peak at higher frequency was found for chitosan and chitosan containing LiClO 4 films. The peak at lower frequency was attributed to Li + conduction since it appeared only for the chitosan containing LiClO 4 . The peak frequency varied with the temperature according to an Arrhenius process with activation energies of circa of 0.6 and 0.45 eV, for H + and Li + conduction, respectively.

  10. Radiation Synthesis and Application of Carboxymethylated Chitosan Hydrogels

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Young Chang

    2007-08-15

    This research proposal is to investigate radiation effect of carboxymethylated chitosan in order to obtain the crosslinked carboxymethylated chitosan. The application studies on CM-chitosan- based intelligent hydrogels will be tried too. Chitin is the most abundant natural amino polysaccharide and estimated to be produced annually almost as much as cellulose. Chitosan is the deacetylated product of chitin showing the enhanced solubility in dilute acids, further, carboxymethylated chitosan (CM-chitosan) can solve in both acidic and basic physiological media, which might be good candidates as a kind of biomedical materials. Radiation technique is an important method for modification of chitin derivatives. It includes radiation-induced degradation, grafting, and crosslinking. It was found that CM-chitosan degraded in solid state or dilute aqueous solution under irradiation, but crosslinked at paste-like sate when the concentration of CM-chitosan is more than 10%. Both degraded and crosslinked CM-chitosan have antibacterial activity, so it is essential to investigate in detail the radiation effect of CM-chitosan. Study on radiation effect of CM-chitosan in different condition is beneficial to modification of CM-chitosan by irradiation technique. However, little study was reported on radiation crosslinking and application of CM-chitosan. The radiation-closslinked CM-chitosan synthesized from chitosan was characterized by a Fourier transform infrared spectroscopy (FT-IR) analysis. A kinetic swelling in water and the mechanical properties such as a gelation, water absorptivity, and gel strength were also investigated. For the preparation of crosslinked CM-chitosan by using gamma irradiation, the concentration of an aqueous CM-chitosan is above 10wt%. We confirmed that the gel contents was in the range of 15-63%, and when the irradiation dose was increased, the degree of gelation was decreased by disintegration of the CM-chitosan. In conclusion, we developed a new

  11. 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.

  12. Isolation and characterization of chitin and chitosan from marine origin.

    Science.gov (United States)

    Nwe, Nitar; Furuike, Tetsuya; Tamura, Hiroshi

    2014-01-01

    Nowadays, chitin and chitosan are produced from the shells of crabs and shrimps, and bone plate of squid in laboratory to industrial scale. Production of chitosan involved deproteinization, demineralization, and deacetylation. The characteristics of chitin and chitosan mainly depend on production processes and conditions. The characteristics of these biopolymers such as appearance of polymer, turbidity of polymer solution, degree of deacetylation, and molecular weight are of major importance on applications of these polymers. This chapter addresses the production processes and conditions to produce chitin, chitosan, and chito-oligosaccharide and methods for characterization of chitin, chitosan, and chito-oligosaccharide. © 2014 Elsevier Inc. All rights reserved.

  13. Synthesize and Characterization of Hydroxypropyl-N-octanealkyl Chitosan Ramification

    Science.gov (United States)

    Tan, Fu-neng

    2018-03-01

    A new type of amphiphilic ramification, hydroxypropyl-N-octanealkyl chitosan was prepared from chitosan via hydrophilic group and hydrophobic group were introduced. We could protect the amino group of chitosan via the reaction of chitosan and benzaldehyde could get Schiff base structure. Structures of the products were characterized with FT-IR, elemental analysis, themogrammetry (TG) analysis and X-ray diffraction. The degree of substitution of hydrophobic group was studied by elemental analysis. The result showed this chitosan ramification was soluble, biocompatible, biodegradable and nontoxic.

  14. Radiation Synthesis and Application of Carboxymethylated Chitosan Hydrogels

    International Nuclear Information System (INIS)

    Noh, Young Chang

    2007-08-01

    This research proposal is to investigate radiation effect of carboxymethylated chitosan in order to obtain the crosslinked carboxymethylated chitosan. The application studies on CM-chitosan- based intelligent hydrogels will be tried too. Chitin is the most abundant natural amino polysaccharide and estimated to be produced annually almost as much as cellulose. Chitosan is the deacetylated product of chitin showing the enhanced solubility in dilute acids, further, carboxymethylated chitosan (CM-chitosan) can solve in both acidic and basic physiological media, which might be good candidates as a kind of biomedical materials. Radiation technique is an important method for modification of chitin derivatives. It includes radiation-induced degradation, grafting, and crosslinking. It was found that CM-chitosan degraded in solid state or dilute aqueous solution under irradiation, but crosslinked at paste-like sate when the concentration of CM-chitosan is more than 10%. Both degraded and crosslinked CM-chitosan have antibacterial activity, so it is essential to investigate in detail the radiation effect of CM-chitosan. Study on radiation effect of CM-chitosan in different condition is beneficial to modification of CM-chitosan by irradiation technique. However, little study was reported on radiation crosslinking and application of CM-chitosan. The radiation-closslinked CM-chitosan synthesized from chitosan was characterized by a Fourier transform infrared spectroscopy (FT-IR) analysis. A kinetic swelling in water and the mechanical properties such as a gelation, water absorptivity, and gel strength were also investigated. For the preparation of crosslinked CM-chitosan by using gamma irradiation, the concentration of an aqueous CM-chitosan is above 10wt%. We confirmed that the gel contents was in the range of 15-63%, and when the irradiation dose was increased, the degree of gelation was decreased by disintegration of the CM-chitosan. In conclusion, we developed a new

  15. TRANSPORT MECHANISM STUDIES OF CHITOSAN ELECTROLYTE SYSTEMS

    International Nuclear Information System (INIS)

    Navaratnam, S.; Ramesh, K.; Ramesh, S.; Sanusi, A.; Basirun, W.J.; Arof, A.K.

    2015-01-01

    ABSTRACT: Knowledge of ion-conduction mechanisms in polymers is important for designing better polymer electrolytes for electrochemical devices. In this work, chitosan-ethylene carbonate/propylene carbonate (chitosan-EC/PC) system with lithium acetate (LiCH 3 COO) and lithium triflate (LiCF 3 SO 3 ) as salts were prepared and characterized using electrochemical impedance spectroscopy to study the ion-conduction mechanism. It was found that the electrolyte system using LiCF 3 SO 3 salt had a higher ionic conductivity, greater dielectric constant and dielectric loss value compared to system using LiCH 3 COO at room temperature. Hence, it may be inferred that the system incorporated with LiCF 3 SO 3 dissociated more readily than LiCH 3 COO. Conductivity mechanism for the systems, 42 wt.% chitosan- 28 wt.% LiCF 3 SO 3 -30 wt.% EC/PC (CLT) and 42 wt.% chitosan-28 wt.% LiCH 3 COO-30 wt.% EC/PC (CLA) follows the overlapping large polaron tunneling (OLPT) model. Results show that the nature of anion size influences the ionic conduction of chitosan based polymer electrolytes. The conductivity values of the CLA system are found to be higher than that of CLT system at higher temperatures. This may be due to the vibration of bigger triflate anions would have hindered the lithium ion movements. FTIR results show that lithium ions can form complexation with polymer host which would provide a platform for ion hopping

  16. Effects of sulfate chitosan derivatives on nonalcoholic fatty liver disease

    Science.gov (United States)

    Yu, Mingming; Wang, Yuanhong; Jiang, Tingfu; Lv, Zhihua

    2014-06-01

    Sulfate chitosan derivatives have good solubility and therapeutic effect on the cell model of NAFLD. The aim of this study was to examine the therapeutic effect of sulfate chitosan derivatives on NAFLD. The male Wistar rats were orally fed high fat emulsion and received sulfate chitosan derivatives for 5 weeks to determine the pre-treatment effect of sulfate chitosan derivatives on NAFLD. To evaluate the therapeutic effect of sulfate chitosan derivatives on NAFLD, the rats were orally fed with high concentration emulsion for 5 weeks, followed by sulfate chitosan derivatives for 3 weeks. Histological analysis and biomedical assays showed that sulfate chitosan derivatives can dramatically prevent the development of hepatic steatosis in hepatocyte cells. In animal studies, pre-treatment and treatment with sulfate chitosan derivatives significantly protected against hepatic steatohepatitis induced by high fat diet according to histological analysis. Furthermore, increased TC, ALT, MDA, and LEP in NAFLD were significantly ameliorated by pre-treatment and treatment with sulfate chitosan derivatives. Furthermore, increased TG, AST, and TNF-α in NAFLD were significantly ameliorated by treatment with sulfate chitosan derivatives. Sulfate chitosan derivatives have good pre-treatment and therapeutic effect on NAFLD.

  17. Determination of the Optimum Conditions for Production of Chitosan Nanoparticles

    Directory of Open Access Journals (Sweden)

    A. Dustgani

    2007-12-01

    Full Text Available Bioedegradable nanoparticles are intensively investigated for their potential applications in drug delivery systems. Being a biocompatible and biodegradable polymer, chitosan holds great promise for use in this area. This investigation was concerned with determination and optimization of the effective parameters involved in the production of chitosan nanoparticles using ionic gelation method. Studied variables were concentration and pH of the chitosan solution, the ratio of chitosan to sodium tripolyphosphate therein and the molecular weight of chitosan. For this purpose, Taguchistatistical method was used for design of experiments in three levels. The size of chitosan nanoparticle was determined using laser light scattering. The experimental results showed that concentration of chitosan solution was the most important parameter and chitosan molecular weight the least effective parameter. The optimum conditions for preparation of nanoparticles were found to be 1 mg/mL chitosan solution with pH=5, chitosan to sodium tripolyphosphate ratio of 3 and chitosan molecular weight of 200,000 daltons. The average nanoparticle size at optimum conditions was found to be about 150 nm.

  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. Degradation of chitosan-based materials after different sterilization treatments

    International Nuclear Information System (INIS)

    San Juan, A; Montembault, A; Royaud, I; David, L; Gillet, D; Say, J P; Rouif, S; Bouet, T

    2012-01-01

    Biopolymers have received in recent years an increasing interest for their potential applications in the field of biomedical engineering. Among the natural polymers that have been experimented, chitosan is probably the most promising in view of its exceptional biological properties. Several techniques may be employed to sterilize chitosan-based materials. The aim of our study was to compare the effect of common sterilization treatments on the degradation of chitosan-based materials in various physical states: solutions, hydrogels and solid flakes. Four sterilization methods were compared: gamma irradiation, beta irradiation, exposure to ethylene oxide and saturated water steam sterilization (autoclaving). Exposure to gamma or beta irradiation was shown to induce an important degradation of chitosan, regardless of its physical state. The chemical structure of chitosan flakes was preserved after ethylene oxide sterilization, but this technique has a limited use for materials in the dry state. Saturated water steam sterilization of chitosan solutions led to an important depolymerization. Nevertheless, steam sterilization of chitosan flakes bagged or dispersed in water was found to preserve better the molecular weight of the polymer. Hence, the sterilization of chitosan flakes dispersed in water would represent an alternative step for the preparation of sterilized chitosan solutions. Alternatively, autoclaving chitosan physical hydrogels did not significantly modify the macromolecular structure of the polymer. Thus, this method is one of the most convenient procedures for the sterilization of physical chitosan hydrogels after their preparation.

  20. Effect of chitosan coatings on postharvest green asparagus quality.

    Science.gov (United States)

    Qiu, Miao; Jiang, Hengjun; Ren, Gerui; Huang, Jianying; Wang, Xiangyang

    2013-02-15

    Fresh postharvest green asparagus rapidly deteriorate due to its high respiration rate. The main benefits of edible active coatings are their edible characteristics, biodegradability and increase in food safety. In this study, the quality of the edible coatings based on 0.50%, 0.25% high-molecular weight chitosan (H-chitosan), and 0.50%, 0.25% low-molecular weight chitosan (L-chitosan) on postharvest green asparagus was investigated. On the basis of the results obtained, 0.25% H-chitosan and 0.50% L-chitosan treatments ensured lower color variation, less weight loss and less ascorbic acid, decrease presenting better quality of asparagus than other concentrations of chitosan treatments and the control during the cold storage, and prolonging a shelf life of postharvest green asparagus. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Chitosan Fibers Modified with HAp/β–TCP Nanoparticles

    Directory of Open Access Journals (Sweden)

    Dariusz Wawro

    2011-10-01

    Full Text Available 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 wt% acetic acid. The properties of the spinning solutions were examined. Chitosan fibers modified with nanoparticles of HAp/β-TCP were characterized by a level of tenacity and calcium content one hundred times higher than that of regular chitosan fibers.

  2. 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)

  3. Suppression of Zn stress on barley by irradiated chitosan

    International Nuclear Information System (INIS)

    Nagasawa, N.; Mitomo, H.; Ha, P.T.L.; Watanabe, S.; Ito, T.; Takeshita, H.; Yoshii, F.; Kume, T.

    2001-01-01

    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 5 to ca. 6 x 10 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 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)

  4. Electrospinning and stabilization of chitosan nanofiber mats

    Science.gov (United States)

    Grimmelsmann, N.; Grothe, T.; Homburg, S. V.; Ehrmann, A.

    2017-10-01

    Chitosan is of special interest for biotechnological and medical applications due to its antibacterial, antifungal and other intrinsic physical and chemical properties. The biopolymer can, e.g., be used for biotechnological purposes, as a filter medium, in medical products, etc. In all these applications, the inner surface should be maximized to increase the contact area with the filtered medium etc. and thus the chitosan’s efficacy. Chitosan dissolves in acidic solutions, opposite to neutral water. Electrospinning is possible, e.g., by co-spinning with PEO (poly(ethylene oxide)). Tests with different chitosan:PEO ratios revealed that higher PEO fractions resulted in better spinnability and more regular fibre mats, but make stabilization of the fibre structure more challenging.

  5. Chitosan Microspheres as Radiolabeled Delivery Devices

    International Nuclear Information System (INIS)

    Permtermsin, Chalermsin; Ngamprayad, Tippanan; Phumkhem, Sudkanung; Srinuttrakul, Wannee; Kewsuwan, Prartana

    2007-08-01

    Full text: This study optimized conditions for preparing, characterizing, radiolabeled of chitosan microspheres and the biodistribution of 99mTc-Chitosan microspheres after intravenous administration. Particle size distribution of the microspheres was determined by light scattering. Zeta potential was studied by dynamic light scattering and electrophoresis technique. Biodistribution studies were performed by radiolabeling using 99mTc. The results shown that geometric mean diameter of the microspheres was found to be 77.26?1.96 ?m. Microsphere surface charge of chitosan microspheres was positive charge and zeta potential was 25.80 ? 0.46 mV. The labeling efficiency for this condition was more than 95% and under this condition was stable for at least 6 h. Radioactivity

  6. Chitosan nanoparticles enhances the anti-quorum sensing activity of kaempferol.

    Science.gov (United States)

    Ilk, Sedef; Sağlam, Necdet; Özgen, Mustafa; Korkusuz, Feza

    2017-01-01

    Quorum sensing (QS) is a cell density dependent expression of species in bacteria mediated by compounds called autoinducers (AI). Several processes responsible for successful establishment of bacterial infection are mediated by QS. Inhibition of QS is therefore being considered as a new target for antimicrobial chemotherapy. Flavonoid compounds are strong antioxidant and antimicrobial agents but their applications are limited due to their poor dissolution and bioavailability. Our objective was to investigate the effect of kaempferol loaded chitosan nanoparticles on modulating QS mediated by AI in model bioassay test systems. For this purpose, kaempferol loaded nanoparticles were synthesized and characterized in terms of hydrodynamic diameter, hydrogen bonding, amorphous transformation and antioxidant activity. QS inhibition in time dependent manner of nanoparticles was measured in violacein pigment producing using the biosensor strain Chromobacterium violaceum CV026 mediated by AI known as acylated homoserine lactone (AHL). Our results indicated that the average kaempferol loaded chitosan/TPP nanoparticle size and zeta potential were 192.27±13.6nm and +35mV, respectively. The loading and encapsulation efficiency of kaempferol into chitosan/TPP nanoparticles presented higher values between 78 and 93%. Kaempferol loaded chitosan/TPP nanoparticle during the 30 storage days significantly inhibited the production of violacein pigment in Chromobacterium violaceum CV026. The observation that kaempferol encapsulated chitosan nanoparticles can inhibit QS related processes opens up an exciting new strategy for antimicrobial chemotherapy as stable QS-based anti-biofilm agents. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Solid polymer electrolyte from phosphorylated chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Fauzi, Iqbal, E-mail: arcana@chem.itb.ac.id; Arcana, I Made, E-mail: arcana@chem.itb.ac.id [Inorganic and Physical Chemistry Research Groups, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia)

    2014-03-24

    Recently, the need of secondary battery application continues to increase. The secondary battery which using a liquid electrolyte was indicated had some weakness. A solid polymer electrolyte is an alternative electrolytes membrane which developed in order to replace the liquid electrolyte type. In the present study, the effect of phosphorylation on to polymer electrolyte membrane which synthesized from chitosan and lithium perchlorate salts was investigated. The effect of the component’s composition respectively on the properties of polymer electrolyte, was carried out by analyzed of it’s characterization such as functional groups, ion conductivity, and thermal properties. The mechanical properties i.e tensile resistance and the morphology structure of membrane surface were determined. The phosphorylation processing of polymer electrolyte membrane of chitosan and lithium perchlorate was conducted by immersing with phosphoric acid for 2 hours, and then irradiated on a microwave for 60 seconds. The degree of deacetylation of chitosan derived from shrimp shells was obtained around 75.4%. Relative molecular mass of chitosan was obtained by viscometry method is 796,792 g/mol. The ionic conductivity of chitosan membrane was increase from 6.33 × 10{sup −6} S/cm up to 6.01 × 10{sup −4} S/cm after adding by 15 % solution of lithium perchlorate. After phosphorylation, the ionic conductivity of phosphorylated lithium chitosan membrane was observed 1.37 × 10{sup −3} S/cm, while the tensile resistance of 40.2 MPa with a better thermal resistance. On the strength of electrolyte membrane properties, this polymer electrolyte membrane was suggested had one potential used for polymer electrolyte in field of lithium battery applications.

  8. Study on the degradation of chitosan slurries

    Directory of Open Access Journals (Sweden)

    Benjamin Martini

    2016-01-01

    Full Text Available In the present work, we measured the degradation rate of different chitosan slurries. Several parameters were monitored such as temperature (25 °C, 37 °C, 50 °C; chitosan concentration (1% and 2% (w/V; and polymer molecular weight. The samples were tested in dynamic sweep test mode. This test is able to provide a reliable estimation of viscosity variations of the slurries; in turn, these variations could be related to degradation rate of the system in the considered conditions. The resulting information is particularly important especially in applications in which there is a close relationship between physical properties and molecular structure.

  9. Preparations, properties and applications of chitosan based nanofibers fabricated by electrospinning

    Directory of Open Access Journals (Sweden)

    2011-04-01

    Full Text Available Chitosan is soluble in most acids. The protonation of the amino groups on the chitosan backbone inhibits the electrospinnability of pure chitosan. Recently, electrospinning of nanofibers based on chitosan has been widely researched and numerous nanofibers containing chitosan have been prepared by decreasing the number of the free amino groups of chitosan as the nanofibiers have enormous possibilities for better utilization in various areas. This article reviews the preparations and properties of the nanofibers which were electrospun from pure chitosan, blends of chitosan and synthetic polymers, blends of chitosan and protein, chitosan derivatives, as well as blends of chitosan and inorganic nanoparticles, respectively. The applications of the nanofibers containing chitosan such as enzyme immobilization, filtration, wound dressing, tissue engineering, drug delivery and catalysis are also summarized in detail.

  10. Chitosan Effects on Plant Systems

    Directory of Open Access Journals (Sweden)

    Massimo Malerba

    2016-06-01

    Full Text Available Chitosan (CHT is a natural, safe, and cheap product of chitin deacetylation, widely used by several industries because of its interesting features. The availability of industrial quantities of CHT in the late 1980s enabled it to be tested in agriculture. CHT has been proven to stimulate plant growth, to protect the safety of edible products, and to induce abiotic and biotic stress tolerance in various horticultural commodities. The stimulating effect of different enzyme activities to detoxify reactive oxygen species suggests the involvement of hydrogen peroxide and nitric oxide in CHT signaling. CHT could also interact with chromatin and directly affect gene expression. Recent innovative uses of CHT include synthesis of CHT nanoparticles as a valuable delivery system for fertilizers, herbicides, pesticides, and micronutrients for crop growth promotion by a balanced and sustained nutrition. In addition, CHT nanoparticles can safely deliver genetic material for plant transformation. This review presents an overview on the status of the use of CHT in plant systems. Attention was given to the research that suggested the use of CHT for sustainable crop productivity.

  11. 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

  12. Inhibition of Glomerular Mesangial Cell Proliferation by siPDGF-B- and siPDGFR-β-Containing Chitosan Nanoplexes.

    Science.gov (United States)

    Salva, Emine; Turan, Suna Özbaş; Akbuğa, Jülide

    2017-05-01

    Mesangioproliferative glomerulonephritis is a disease that has a high incidence in humans. In this disease, the proliferation of glomerular mesangial cells and the production of extracellular matrix are important. In recent years, the RNAi technology has been widely used in the treatment of various diseases due to its capability to inhibit the gene expression with high specificity and targeting. The objective of this study was to decrease mesangial cell proliferation by knocking down PDGF-B and its receptor, PDGFR-β. To be able to use small interfering RNAs (siRNAs) in the treatment of this disease successfully, it is necessary to develop appropriate delivery systems. Chitosan, which is a biopolymer, is used as a siRNA delivery system in kidney drug targeting. In order to deliver siRNA molecules targeted at PDGF-B and PDGFR-β, chitosan/siRNA nanoplexes were prepared. The in vitro characterization, transfection studies, and knockdown efficiencies were studied in immortalized and primary rat mesangial cells. In addition, the effects of chitosan nanoplexes on mesangial cell proliferation and migration were investigated. After in vitro transfection, the PDGF-B and PDGFR-β gene silencing efficiencies of PDGF-B and PDGFR-β targeting siRNA-containing chitosan nanoplexes were 74 and 71% in immortalized rat mesangial cells and 66 and 62% in primary rat mesangial cells, respectively. siPDGF-B- and siPDGFR-β-containing nanoplexes indicated a significant decrease in mesangial cell migration and proliferation. These results suggested that mesangial cell proliferation may be inhibited by silencing of the PDGF-B signaling pathway. Gene silencing approaches with chitosan-based gene delivery systems have promise for the efficient treatment of renal disease.

  13. Synthesis of N-oleyl O-sulfate chitosan from methyl oleate with O-sulfate chitosan as edible film material

    Science.gov (United States)

    Daniel; Sihaloho, O.; Saleh, C.; Magdaleni, A. R.

    2018-04-01

    The research on the synthesis of N-oleyl O-sulfate chitosan through sulfonation reaction on chitosan with ammonium sulfate and followed by amidation reaction using methyl oleate has been done. In this study, chitosan was chemically modified into N-oleyl O-sulfatechitosan as an edible film making material. N-oleyl O-sulfate chitosan was synthesized by reaction between methyl oleate and O-sulfate chitosan. Wherein the depleted chitosan of O-sulfate chitosan into O-sulfate chitosan was obtained by reaction of sulfonation between ammonium sulfate and chitosan aldimine. While chitosan aldimine was obtained through reaction between chitosan with acetaldehyde. The structure of N-oleyl O-sulfate chitosan was characterized by FT-IR analysis which showed vibration uptake of C-H sp3 group, S=O group, and carbonyl group C=O of the ester. The resulting of N-oleyl O-sulfate chitosan yielded a percentage of 93.52%. Hydrophilic-Lipophilic Balance (HLB) test results gave a value of 6.68. In the toxicity test results of N-oleyl O-sulfate chitosan obtained LC50 value of 3738.4732 ppm. In WVTR (Water Vapor Transmission Rate) test results for chitosan film was 407.625 gram/m2/24 hours and N-oleylO-sulfate chitosan film was 201.125 gram/m2/24 hours.

  14. Chitosan and Its Derivatives for Application in Mucoadhesive Drug Delivery Systems

    Directory of Open Access Journals (Sweden)

    Twana Mohammed M. Ways

    2018-03-01

    Full Text Available Mucoadhesive drug delivery systems are desirable as they can increase the residence time of drugs at the site of absorption/action, provide sustained drug release and minimize the degradation of drugs in various body sites. Chitosan is a cationic polysaccharide that exhibits mucoadhesive properties and it has been widely used in the design of mucoadhesive dosage forms. However, its limited mucoadhesive strength and limited water-solubility at neutral and basic pHs are considered as two major drawbacks of its use. Chemical modification of chitosan has been exploited to tackle these two issues. In this review, we highlight the up-to-date studies involving the synthetic approaches and description of mucoadhesive properties of chitosan and chitosan derivatives. These derivatives include trimethyl chitosan, carboxymethyl chitosan, thiolated chitosan, chitosan-enzyme inhibitors, chitosan-ethylenediaminetetraacetic acid (chitosan-EDTA, half-acetylated chitosan, acrylated chitosan, glycol chitosan, chitosan-catechol, methyl pyrrolidinone-chitosan, cyclodextrin-chitosan and oleoyl-quaternised chitosan. We have particularly focused on the effect of chemical derivatization on the mucoadhesive properties of chitosan. Additionally, other important properties including water-solubility, stability, controlled release, permeation enhancing effect, and in vivo performance are also described.

  15. Functional Comparison for Lipid Metabolism and Intestinal and Fecal Microflora Enzyme Activities between Low Molecular Weight Chitosan and Chitosan Oligosaccharide in High-Fat-Diet-Fed Rats.

    Science.gov (United States)

    Chiu, Chen-Yuan; Feng, Shih-An; Liu, Shing-Hwa; Chiang, Meng-Tsan

    2017-07-24

    The present study investigated and compared the regulatory effects on the lipid-related metabolism and intestinal disaccharidase/fecal bacterial enzyme activities between low molecular weight chitosan and chitosan oligosaccharide in high-fat-diet-fed rats. Diet supplementation of low molecular weight chitosan showed greater efficiency than chitosan oligosaccharide in suppressing the increased weights in body and in liver and adipose tissues of high-fat-diet-fed rats. Supplementation of low molecular weight chitosan also showed a greater improvement than chitosan oligosaccharide in imbalance of plasma, hepatic, and fecal lipid profiles, and intestinal disaccharidase activities in high-fat-diet-fed rats. Moreover, both low molecular weight chitosan and chitosan oligosaccharide significantly decreased the fecal microflora mucinase and β-glucuronidase activities in high-fat-diet-fed rats. These results suggest that low molecular weight chitosan exerts a greater positive improvement than chitosan oligosaccharide in lipid metabolism and intestinal disaccharidase activity in high-fat-diet-induced obese rats.

  16. 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.

  17. Bromine pretreated chitosan for adsorption of lead

    Indian Academy of Sciences (India)

    Pollution by heavy metals like lead (II) is responsible for health hazards and environmental degradation. Adsorption is a prevalent method applied for removal of heavy metal pollutants from water. This study explored adsorption performances of 30% bromine pretreated chitosan for lead (II) abatement from water. Bromine ...

  18. Synthesis and characterization of carboxymethyl chitosan hydrogel ...

    Indian Academy of Sciences (India)

    Local application of drug delivery system could be very. ∗. Author for ... In this study, chitosan was modified by car- ... C18 (250 × 4·6mm ID, 5 μm pore size) column with auto .... Some amount of drug was lost during washing of hydrogels.

  19. Chitosan-based nanocarriers for antimalarials

    Science.gov (United States)

    Dreve, Simina; Kacso, Iren; Popa, Adriana; Raita, Oana; Bende, A.; Borodi, Gh.; Bratu, I.

    2012-02-01

    The objective of this research was to synthesize and characterize chitosan-based liquid and solid materials with unique absorptive and mechanical properties as carriers for quinine - one of the most used antimalarial drug. The use of chitosan (CTS) as base in polyelectrolyte complex systems, to prepare solid release systems as sponges is presented. The preparation by double emulsification of CTS hydrogels carrying quinine as anti-malarial drug is reported. The concentration of quinine in the CTS hydrogel was 0.08 mmol. Chitosan - drug loaded hydrogel was used to generate solid sponges by freeze-drying at -610°C and 0.09 atm. Structural investigations of the solid formulations were done by Fourier-transformed infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-VIS), spectrofluorimetry, differential scanning calorimetry (DSC) and X-ray diffractometry. The results indicated that the drug molecule is forming temporary chelates in CTS hydrogels and sponges. Electron paramagnetic resonance (EPR) demonstrates the presence of free radicals in a wide range and the antioxidant activity for chitosan - drug supramolecular cross-linked assemblies.

  20. Development of electrosprayed mucoadhesive chitosan microparticles

    DEFF Research Database (Denmark)

    Moreno, Jorge Alberto S.; Mendes, Ana C.; Stephansen, Karen

    2018-01-01

    The efficacy of chitosan (CS) to be used as drug delivery carrier has previously been reported. However, limited work has been pursued to produce stable and mucoadhesive CS electrosprayed particles for oral drug delivery, which is the aim of this study. Various CS types with different molecular...

  1. Insulin-chitosan polyelectrolyte _anocomplexes: preparation ...

    African Journals Online (AJOL)

    Objectives: To formulate chitosan nanoparticles with specific combinations of molecular weight and degree of deacetylation (DDA) that could be developed into an oral insulin delivery system. Methods: This study was conducted at Jordanian Pharmaceutical Manufacturing Company (JPM), Jordan in the period 2006-2009.

  2. Chitosan nanofibers for transbuccal insulin delivery.

    Science.gov (United States)

    Lancina, Michael G; Shankar, Roopa Kanakatti; Yang, Hu

    2017-05-01

    In this work, they aimed at producing chitosan based nanofiber mats capable of delivering insulin via the buccal mucosa. Chitosan was electrospun into nanofibers using poly(ethylene oxide) (PEO) as a carrier molecule in various feed ratios. The mechanical properties and degradation kinetics of the fibers were measured. Insulin release rates were determined in vitro using an ELISA assay. The bioactivity of released insulin was measured in terms of Akt activation in pre-adipocytes. Insulin permeation across the buccal mucosa was measured in an ex-vivo porcine transbuccal model. Fiber morphology, mechanical properties, and in vitro stability were dependent on PEO feed ratio. Lower PEO content blends produced smaller diameter fibers with significantly faster insulin release kinetics. Insulin showed no reduction in bioactivity due to electrospinning. Buccal permeation of insulin facilitated by high chitosan content blends was significantly higher than that of free insulin. Taken together, the work demonstrates that chitosan-based nanofibers have the potential to serve as a transbuccal insulin delivery vehicle. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1252-1259, 2017. © 2017 Wiley Periodicals, Inc.

  3. Chitosan catalyzes hydrogen evolution at mercury electrodes

    Czech Academy of Sciences Publication Activity Database

    Paleček, Emil; Římánková, Ludmila

    2014-01-01

    Roč. 44, JUL2014 (2014), s. 59-62 ISSN 1388-2481 R&D Projects: GA ČR(CZ) GAP301/11/2055 Institutional support: RVO:68081707 Keywords : Chitosan * Glucosamine-containing polymers * Catalytic hydrogen evolution Subject RIV: BO - Biophysics Impact factor: 4.847, year: 2014

  4. Effects of Chitosan Alkali Pretreatment on the Preparation of Electrospun PCL/Chitosan Blend Nanofibrous Scaffolds for Tissue Engineering Application

    Directory of Open Access Journals (Sweden)

    Fatemeh Roozbahani

    2013-01-01

    Full Text Available Recently, nanofibrous scaffolds have been used in the field of biomedical engineering as wound dressings, tissue engineering scaffolds, and drug delivery applications. The electrospun nanofibrous scaffolds can be used as carriers for several types of drugs, genes, and growth factors. PCL is one of the most commonly applied synthetic polymers for medical use because of its biocompatibility and slow biodegradability. PCL is hydrophobic and has no cell recognition sites on its structure. Electrospinning of chitosan and PCL blend was investigated in formic acid/acetic acid as the solvent with different PCL/chitosan ratios. High viscosity of chitosan solutions makes difficulties in the electrospinning process. Strong hydrogen bonds in a 3D network in acidic condition prevent the movement of polymeric chains exposed to the electrical field. Consequently, the amount of chitosan in PCL/chitosan blend was limited and more challenging when the concentration of PCL increases. The treatment of chitosan in alkali condition under high temperature reduced its molecular weight. Longer treatment time further decreased the molecular weight of chitosan and hence its viscosity. Electrospinning of PCL/chitosan blend was possible at higher chitosan ratio, and SEM images showed a decrease in fiber diameter and narrower distribution with increase in the chitosan ratio.

  5. The effect of chitosan and whey proteins-chitosan films on the growth of Penicillium expansum in apples.

    Science.gov (United States)

    Simonaitiene, Dovile; Brink, Ieva; Sipailiene, Ausra; Leskauskaite, Daiva

    2015-05-01

    Penicillium expansum causes a major post-harvest disease of apples. The aim of this study was to investigate the inhibition effect of chitosan and whey proteins-chitosan films containing different amounts of quince and cranberry juice against P. expansum on the simulation medium and on apples. The mechanical properties of films were also evaluated. The presence of cranberry and quince juice in the composition of chitosan and whey proteins-chitosan films caused a significant (P ≤ 0.05) increase in elasticity and decrease in tensile strength of films. Chitosan and whey proteins-chitosan films with quince and cranberry juice demonstrated a significant (P ≤ 0.05) inhibition effect against P. expansum growth on the simulated medium and apples. The presence of cranberry juice in the composition of chitosan and whey proteins-chitosan films resulted in a longer lag phase and a lower P. expansum growth rate on the simulation medium in comparison with films made with the addition of quince juice. These differences were not evident when experiment was conducted with apples. Addition of quince and cranberry juice to the chitosan and whey proteins-chitosan films as natural antifungal agents has some potential for prolonging the shelf life of apples. © 2014 Society of Chemical Industry.

  6. Fragmentation of the radiation degraded chitosan by centrifugal filter and application of the fragmented chitosan in cotton fabrics finishing

    International Nuclear Information System (INIS)

    Luu Thi Tho; Nguyen Van Thong; Vu Thi Hong Khanh; Tran Minh Quynh

    2014-01-01

    Three kind of Vietnamese chitosans with the same deacetylation degrees of about 75% and viscosity average molecular weights are 69.000, 187.000 and 345.000 Da, respectively, were produced from shrimp shells and cuttle-bone at the MTV chitosan company (Kien Giang). These chitosans were irradiated at 25, 50, 75, 100, 200 and 500 kGy under Cobalt-60 gamma source at Hanoi Irradiation Center in order to prepare a series of chitosan segments with wide distribution of molecular weights. Different chitosan samples of the predetermined average molecular weight from 3,000 to 50,000 Da were separated from the irradiated chitosans by ultrafiltration with series of filter membranes (Centriprep devices). Molecular properties of the fragmented chitosans were analysed with gel permeation chromatography, Fourier transfer infra red spectrometry, and the results suggested that principal characteristics of chitosan were not affected by gamma irradiation, even its deacetylation degrees was increased. Solubility of the fragmented chitosans were much improved by radiation processing, and the chitosans having molecular weights below 5.000 Da were water-soluble polymers, which can easily apply as the auxiliary agent in textile. (author)

  7. Properties of Chitosan-Laminated Collagen Film

    Directory of Open Access Journals (Sweden)

    Vera Lazić

    2012-01-01

    Full Text Available The objective of this study is to determine physical, mechanical and barrier properties of chitosan-laminated collagen film. Commercial collagen film, which is used for making collagen casings for dry fermented sausage production, was laminated with chitosan film layer in order to improve the collagen film barrier properties. Different volumes of oregano essential oil per 100 mL of filmogenic solution were added to chitosan film layer: 0, 0.2, 0.4, 0.6 and 0.8 mL to optimize water vapour barrier properties. Chitosan layer with 0.6 or 0.8 % of oregano essential oil lowered the water vapour transmission rate to (1.85±0.10·10–6 and (1.78±0.03·10–6 g/(m2·s·Pa respectively, compared to collagen film ((2.51±0.05·10–6 g/(m2·s·Pa. However, chitosan-laminated collagen film did not show improved mechanical properties compared to the collagen one. Tensile strength decreased from (54.0±3.8 MPa of the uncoated collagen film to (36.3±4.0 MPa when the film was laminated with 0.8 % oregano essential oil chitosan layer. Elongation at break values of laminated films did not differ from those of collagen film ((18.4±2.7 %. Oxygen barrier properties were considerably improved by lamination. Oxygen permeability of collagen film was (1806.8±628.0·10–14 cm3/(m·s·Pa and values of laminated films were below 35·10–14 cm3/(m·s·Pa. Regarding film appearance and colour, lamination with chitosan reduced lightness (L and yellowness (+b of collagen film, while film redness (+a increased. These changes were not visible to the naked eye.

  8. Thiolated chitosan nanoparticles as a delivery system for antisense therapy: evaluation against EGFR in T47D breast cancer cells

    Directory of Open Access Journals (Sweden)

    Talaei F

    2011-09-01

    Full Text Available Fatemeh Talaei1, Ebrahim Azizi2, Rassoul Dinarvand3, Fatemeh Atyabi31Novel Drug Delivery Systems Lab, 2Molecular Research Lab, Department of Pharmacology and Toxicology, 3Nanotechnology Research Centre, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, IranAbstract: Thiolated chitosan has high transfection and mucoadhesive properties. We investigated the potential of two recently synthesized polymers: NAC-C (N-acetyl cysteine-chitosan and NAP-C (N-acetyl penicillamine-chitosan in anticancer drug delivery targeting epidermal growth factor receptor (EGFR. Doxorubicin (DOX and antisense oligonucleotide (ASOND-loaded polymer nanoparticles were prepared in water by a gelation process. Particle characterization, drug loading, and drug release were evaluated. To verify drug delivery efficiency in vitro experiments on a breast cancer cell line (T47D were performed. EGFR gene and protein expression was analyzed by real time quantitative polymerase chain reaction and Western blotting, respectively. A loading percentage of 63% ± 5% for ASOND and 70% ± 5% for DOX was achieved. Drug release data after 15 hours showed that ASOND and DOX were completely released from chitosan-based particles while a lower and more sustained release of only 22% ± 8% was measured for thiolated particles. In a cytosol simulated release medium/reducing environment, such as found intracellularly, polymer-based nanoparticles dissociated, liberating approximately 50% of both active substances within 7 hours. ASOND-loaded polymer nanoparticles had higher stability and high mucoadhesive properties. The ASOND-loaded thiolated particles significantly suppressed EGFR gene expression in T47D cells compared with ASOND-loaded chitosan particles and downregulated EGFR protein expression in cells. This study could facilitate future investigations into the functionality of NAP-C and NAC-C polymers as an efficient ASOND delivery system in vitro and in vivo

  9. Characterization of physicochemical and colloidal properties of hydrogel chitosan-coated iron-oxide nanoparticles for cancer therapy

    International Nuclear Information System (INIS)

    Catalano, E; Di Benedetto, A

    2017-01-01

    Superparamagnetic iron oxide nanoparticles have recently been investigated for their potential to kill cancer cells with promising results, owing to their ability to be targeted and heated by magnetic fields. In this study, novel hydrogel, chitosan Fe 3 O 4 magnetic nanoparticles were synthesized to induce magnetic hyperthermia, and targeted delivering of chemotherapeutics in the cancer microenvironment. The characteristic properties of synthesized bare and CS-MNPs were analyzed by various analytical methods: X-ray diffraction, Fourier transformed infrared spectroscopy, Scanning electron microscopy and Thermo-gravimetric analysis/differential thermal analysis. Magnetic nanoparticles were successfully synthesized using the co-precipitation method. This synthesis technique resulted in nanoparticles with an average particle size of 16 nm. The pure obtained nanoparticles were then successfully encapsulated with 4-nm-thick chitosan coating. The formation of chitosan on the surface of nanoparticles was confirmed by physicochemical analyses. Heating experiments at safe magnetic field (f = 100 kHz, H =10-20 kA m -1 ) revealed that the maximum achieved temperature of water stable chitosan-coated nanoparticles (50 mg ml -1 ) is fully in agreement with cancer therapy and biomedical applications. (paper)

  10. Characterization of physicochemical and colloidal properties of hydrogel chitosan-coated iron-oxide nanoparticles for cancer therapy

    Science.gov (United States)

    Catalano, E.; Di Benedetto, A.

    2017-05-01

    Superparamagnetic iron oxide nanoparticles have recently been investigated for their potential to kill cancer cells with promising results, owing to their ability to be targeted and heated by magnetic fields. In this study, novel hydrogel, chitosan Fe3O4 magnetic nanoparticles were synthesized to induce magnetic hyperthermia, and targeted delivering of chemotherapeutics in the cancer microenvironment. The characteristic properties of synthesized bare and CS-MNPs were analyzed by various analytical methods: X-ray diffraction, Fourier transformed infrared spectroscopy, Scanning electron microscopy and Thermo-gravimetric analysis/differential thermal analysis. Magnetic nanoparticles were successfully synthesized using the co-precipitation method. This synthesis technique resulted in nanoparticles with an average particle size of 16 nm. The pure obtained nanoparticles were then successfully encapsulated with 4-nm-thick chitosan coating. The formation of chitosan on the surface of nanoparticles was confirmed by physicochemical analyses. Heating experiments at safe magnetic field (f = 100 kHz, H =10-20 kA m-1) revealed that the maximum achieved temperature of water stable chitosan-coated nanoparticles (50 mg ml-1) is fully in agreement with cancer therapy and biomedical applications.

  11. Thiolated chitosans: useful excipients for oral drug delivery.

    Science.gov (United States)

    Werle, Martin; Bernkop-Schnürch, Andreas

    2008-03-01

    To improve the bioavailability of orally administered drugs, formulations based on polymers are of great interest for pharmaceutical technologists. Thiolated chitosans are multifunctional polymers that exhibit improved mucoadhesive, cohesive and permeation-enhancing as well as efflux-pump-inhibitory properties. They can be synthesized by derivatization of the primary amino groups of chitosan with coupling reagents bearing thiol functions. Various data gained in-vitro as well as in-vivo studies clearly demonstrate the potential of thiolated chitosans for oral drug delivery. Within the current review, the synthesis and characterization of thiolated chitosans so far developed is summarized. Features of thiolated chitosans important for oral drug delivery are discussed as well. Moreover, different formulation approaches, such as matrix tablets and micro-/nanoparticles, as well as the applicability of thiolated chitosans for the oral delivery of various substance classes including peptides and efflux pump substrates, are highlighted.

  12. Chitosan pretreatment for cotton dyeing with black tea

    Science.gov (United States)

    Campos, J.; Díaz-García, P.; Montava, I.; Bonet-Aracil, M.; Bou-Belda, E.

    2017-10-01

    Chitosan is used in a wide range of applications due to its intrinsic properties. Chitosan is a biopolymer obtained from chitin and among their most important aspects highlights its bonding with cotton and its antibacterial properties. In this study two different molecular weight chitosan are used in the dyeing process of cotton with black tea to evaluate its influence. In order to evaluate the effect of the pretreatment with chitosan, DSC and reflection spectrophotometer analysis are performed. The curing temperature is evaluated by the DSC analysis of cotton fabric treated with 15 g/L of chitosan, whilst the enhancement of the dyeing is evaluated by the colorimetric coordinates and the K/S value obtained spectrophotometrically. This study shows the extent of improvement of the pretreatment with chitosan in dyeing with natural products as black tea.

  13. Use of the montmorillonite as crosslink agents for chitosan

    International Nuclear Information System (INIS)

    Barbosa, Rossemberg C.; Lima, Rosemary S. Cunha; Braga, Carla R. Costa; Fook, Marcus V. Lia; Silva, Suedina M. Lima

    2009-01-01

    The montmorillonite (the main constituent of bentonite) has been the most commonly used inorganic load in the formation of nanocomposites chitosan / layered silicate. To evaluate its effect as an agent for the reticulation of chitosan, a sodium montmorillonite, Cloisite Na + , supplied by Southern Clay Products, Texas, USA, was used. For the reticulation of chitosan dispersions of chitosan / Cloisite Na + were prepared in different proportions and the obtained films characterized by infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TG). The results indicated that the Cloisite Na + was for efficient and the reticulation of the chitosan and can be used in place of sulfuric acid, which is one of the most common reticulants for chitosan. (author)

  14. Enhancement of Antibacterial activity of Chitosan by gamma irradiation

    International Nuclear Information System (INIS)

    Bashandy, A.S.; Ibrahim, H.M.M.

    2006-01-01

    The antibacterial activity of irradiated and non-irradiated chitosan against E.coli, S.aureus, Salmonella, Strep. fecalis,Closteridium and P. aerugenosa was studied. Up to 1.25 mg/l, chitosan hardly suppressed the growth of all the strains while 3 mg/l of chitosan clearly inhibited the growth of all the studied strains. Therefore, the concentration of 3 mg/l of chitosan in the medium was adopted in this study. Irradiation at 100 KGy under dry conditions was effective in increasing the activity of chitosan and the growth of bacterial strains which was completely inhibited. It was also found that the addition of chitosan to dressing membranes present good barrier properties against microbes especially that irradiated at 100 KGy

  15. Chitosan-Based Nanoparticles for Mucosal Delivery of RNAi Therapeutics

    DEFF Research Database (Denmark)

    Martirosyan, Alina; Olesen, Morten Jarlstad; Howard, Kenneth A.

    2014-01-01

    of the polysaccharide chitosan have been used to facilitate delivery of siRNA across mucosal surfaces following local administration. This chapter describes the mucosal barriers that need to be addressed in order to design an effective mucosal delivery strategy and the utilization of the mucoadhesive properties...... of chitosan. Focus is given to preparation methods and the preclinical application of chitosan nanoparticles for respiratory and oral delivery of siRNA....

  16. Chitin and Chitosan as Direct Compression Excipients in Pharmaceutical Applications

    Science.gov (United States)

    Badwan, Adnan A.; Rashid, Iyad; Al Omari, Mahmoud M.H.; Darras, Fouad H.

    2015-01-01

    Despite the numerous uses of chitin and chitosan as new functional materials of high potential in various fields, they are still behind several directly compressible excipients already dominating pharmaceutical applications. There are, however, new attempts to exploit chitin and chitosan in co-processing techniques that provide a product with potential to act as a direct compression (DC) excipient. This review outlines the compression properties of chitin and chitosan in the context of DC pharmaceutical applications. PMID:25810109

  17. Receptor-mediated gene delivery using chemically modified chitosan

    International Nuclear Information System (INIS)

    Kim, T H; Jiang, H L; Nah, J W; Cho, M H; Akaike, T; Cho, C S

    2007-01-01

    Chitosan has been investigated as a non-viral vector because it has several advantages such as biocompatibility, biodegradability and low toxicity with high cationic potential. However, the low specificity and low transfection efficiency of chitosan need to be solved prior to clinical application. In this paper, we focused on the galactose or mannose ligand modification of chitosan for enhancement of cell specificity and transfection efficiency via receptor-mediated endocytosis in vitro and in vivo

  18. Chitin and Chitosan as Direct Compression Excipients in Pharmaceutical Applications

    Directory of Open Access Journals (Sweden)

    Adnan A. Badwan

    2015-03-01

    Full Text Available Despite the numerous uses of chitin and chitosan as new functional materials of high potential in various fields, they are still behind several directly compressible excipients already dominating pharmaceutical applications. There are, however, new attempts to exploit chitin and chitosan in co-processing techniques that provide a product with potential to act as a direct compression (DC excipient. This review outlines the compression properties of chitin and chitosan in the context of DC pharmaceutical applications.

  19. Effectiveness of chitosan against wine-related microorganisms.

    Science.gov (United States)

    Bağder Elmaci, Simel; Gülgör, Gökşen; Tokatli, Mehmet; Erten, Hüseyin; İşci, Asli; Özçelik, Filiz

    2015-03-01

    The antimicrobial action of chitosan against wine related microorganisms, including Lactobacillus plantarum, Saccharomyces cerevisiae, Oeonococcus oeni, Lactobacillus hilgardii, Brettanomyces bruxellensis, Hanseniaspora uvarum and Zygosaccharomyces bailii was examined in laboratory media. In order to assess the potential applicability of chitosan as a microbial control agent for wine, the effect of chitosan, applied individually and/or in combination with sulphur dioxide (SO2), on the growth of microorganisms involved in various stages of winemaking and on the fermentative performance of S. cerevisiae was investigated. Of the seven wine-related microorganisms studied, S. cerevisiae exhibited the strongest resistance to antimicrobial action of chitosan in laboratory media with a minimum inhibitory concentration (MIC) greater than 2 g/L. L. hilgardii, O. oeni and B. bruxellensis were the most susceptible to chitosan since they were completely inactivated by chitosan at 0.2 g/L. The MIC of chitosan for L. plantarum, H. uvarum and Z. bailii was 2, 0.4 and 0.4 g/L, respectively. In wine experiments, it was found that chitosan had a retarding effect on alcoholic fermentation without significantly altering the viability and the fermentative performance of S. cerevisiae. With regard to non-Saccharomyces yeasts (H. uvarum and Z. bailii) involved in winemaking, the early deaths of these yeasts in mixed cultures with S. cerevisiae were not probably due to the antimicrobial action of chitosan but rather due to ethanol produced by the yeasts. The complex interactions between chitosan and wine ingredients as well as microbial interactions during wine fermentation considerably affect the efficacy of chitosan. It was concluded that chitosan was worthy of further investigation as an alternative or complementary preservative to SO2 in wine industry.

  20. Theoretical studies of ionic conductivity of crosslinked chitosan membranes

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, Ernesto Lopez [Programa de Ingenieria Molecular y Nuevos Materiales, Universidad Autonoma de la Ciudad de Mexico, Fray Servando Teresa de Mier 92, 1er. Piso, Col Centro, Mexico D.F. CP 06080 (Mexico); Oviedo-Roa, R.; Contreras-Perez, Gustavo; Martinez-Magadan, Jose Manuel [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas Norte 152, Col. San Bartolo Atepehuacan, CP 07730 Mexico D.F. (Mexico); Castillo-Alvarado, F.L. [Escuela Superior de Fisica y Matematicas del Instituto Politecnico Nacional, Edificio 9 de la UPALM, Colonia Lindavista, Mexico D.F. CP 07738 (Mexico)

    2010-11-15

    Ionic conductivity of crosslinked chitosan membranes was studied using techniques of molecular modeling and simulation. The COMPASS force field was used. The simulation allows the description of the mechanism of ionic conductivity along the polymer matrix. The theoretical results obtained are compared with experimental results for chitosan membranes. The analysis suggests that the conduction mechanism is portrayed by the overlapping large Polaron tunneling model. In addition, when the chitosan membrane was crosslinked with an appropriate degree of crosslinking its ionic conductivity, at room temperature, was increased by about one order of magnitude. The chitosan membranes can be used as electrolytes in solid state batteries, electric double layer capacitors and fuel cells. (author)

  1. Biochemical properties of Hemigraphis alternata incorporated chitosan hydrogel scaffold.

    Science.gov (United States)

    Annapoorna, M; Sudheesh Kumar, P T; Lakshman, Lakshmi R; Lakshmanan, Vinoth-Kumar; Nair, Shantikumar V; Jayakumar, R

    2013-02-15

    In this work, Hemigraphis alternata extract incorporated chitosan scaffold was synthesized and characterized for wound healing. The antibacterial activity of Hemigraphis incorporated chitosan scaffold (HIC) against Escherichia coli and Staphylococcus aureus was evaluated which showed a reduction in total colony forming units by 45-folds toward E. coli and 25-fold against S. aureus respectively. Cell viability studies using Human Dermal Fibroblast cells (HDF) showed 90% viability even at 48 h when compared to the chitosan control. The herbal scaffold made from chitosan was highly haemostatic and antibacterial. The obtained results were in support that the herbal scaffold can be effectively applied for infectious wounds. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Effect of chitosan coating on the characteristics of DPPC liposomes

    Directory of Open Access Journals (Sweden)

    Mohsen M. Mady

    2010-07-01

    Full Text Available Because it is both biocompatible and biodegradable, chitosan has been used to provide a protective capsule in new drug formulations. The present work reports on investigations into some of the physicochemical properties of chitosan-coated liposomes, including drug release rate, transmission electron microscopy (TEM, zeta potential and turbidity measurement. It was found that chitosan increases liposome stability during drug release. The coating of DPPC liposomes with a chitosan layer was confirmed by electron microscopy and the zeta potential of liposomes. The coating of liposomes by chitosan resulted in a marginal increase in the size of the liposomes, adding a layer of (92 ± 27.1 nm. The liposomal zeta potential was found to be increasingly positive as chitosan concentration increased from 0.1% to 0.3% (w/v, before stabilising at a relatively constant value. Turbidity studies revealed that the coating of DPPC liposomes with chitosan did not significantly modify the main phase transition temperature of DPPC at examined chitosan concentrations. The appropriate combination of liposomal and chitosan characteristics may produce liposomes with specific, prolonged and controlled release.

  3. Advances in preparation and characterization of chitosan nanoparticles for therapeutics.

    Science.gov (United States)

    Chandra Hembram, Krushna; Prabha, Shashi; Chandra, Ramesh; Ahmed, Bahar; Nimesh, Surendra

    2016-01-01

    Polymers have been largely explored for the preparation of nanoparticles due to ease of preparation and modification, large gene/drug loading capacity, and biocompatibility. Various methods have been adapted for the preparation and characterization of chitosan nanoparticles. Focus on the different methods of preparation and characterization of chitosan nanoparticles. Detailed literature survey has been done for the studies reporting various methods of preparation and characterization of chitosan nanoparticles. Published database suggests of several methods which have been developed for the preparation and characterization of chitosan nanoparticles as per the application.

  4. Controlling chitosan-based encapsulation for protein and vaccine delivery

    Science.gov (United States)

    Koppolu, Bhanu prasanth; Smith, Sean G.; Ravindranathan, Sruthi; Jayanthi, Srinivas; Kumar, Thallapuranam K.S.; Zaharoff, David A.

    2014-01-01

    Chitosan-based nano/microencapsulation is under increasing investigation for the delivery of drugs, biologics and vaccines. Despite widespread interest, the literature lacks a defined methodology to control chitosan particle size and drug/protein release kinetics. In this study, the effects of precipitation-coacervation formulation parameters on chitosan particle size, protein encapsulation efficiency and protein release were investigated. Chitosan particle sizes, which ranged from 300 nm to 3 μm, were influenced by chitosan concentration, chitosan molecular weight and addition rate of precipitant salt. The composition of precipitant salt played a significant role in particle formation with upper Hofmeister series salts containing strongly hydrated anions yielding particles with a low polydispersity index (PDI) while weaker anions resulted in aggregated particles with high PDIs. Sonication power had minimal effect on mean particle size, however, it significantly reduced polydispersity. Protein loading efficiencies in chitosan nano/microparticles, which ranged from 14.3% to 99.2%, was inversely related to the hydration strength of precipitant salts, protein molecular weight and directly related to the concentration and molecular weight of chitosan. Protein release rates increased with particle size and were generally inversely related to protein molecular weight. This study demonstrates that chitosan nano/microparticles with high protein loading efficiencies can be engineered with well-defined sizes and controllable release kinetics through manipulation of specific formulation parameters. PMID:24560459

  5. Interaction between chitosan and its related enzymes: A review.

    Science.gov (United States)

    Shinya, Shoko; Fukamizo, Tamo

    2017-11-01

    Chitosan-related enzymes including chitosanases, exo-β-glucosaminidases, and enzymes having chitosan-binding modules recognize ligands through electrostatic interactions between the acidic amino acids in proteins and amino groups of chitosan polysaccharides. However, in GH8 chitosanases, several aromatic residues are also involved in substrate recognition through stacking interactions, and these enzymes consequently hydrolyze β-1,4-glucan as well as chitosan. The binding grooves of these chitosanases are extended and opened at both ends of the grooves, so that the enzymes can clamp a long chitosan polysaccharide. The association/dissociation of positively charged glucosamine residues to/from the binding pocket of a GH2 exo-β-glucosaminidase controls the p K a of the catalytic acid, thereby maintaining the high catalytic potency of the enzyme. In contrast to chitosanases, chitosan-binding modules only accommodate a couple of glucosamine residues, predominantly recognizing the non-reducing end glucosamine residue of chitosan by electrostatic interactions and a hydrogen-bonding network. These structural findings on chitosan-related enzymes may contribute to future applications for the efficient conversion of the chitin/chitosan biomass. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Rapidly photo-cross-linkable chitosan hydrogel for peripheral neurosurgeries.

    Science.gov (United States)

    Rickett, Todd A; Amoozgar, Zohreh; Tuchek, Chad A; Park, Joonyoung; Yeo, Yoon; Shi, Riyi

    2011-01-10

    Restoring continuity to severed peripheral nerves is crucial to regeneration and enables functional recovery. However, the two most common agents for coaptation, sutures and fibrin glues, have drawbacks such as inflammation, pathogenesis, and dehiscence. Chitosan-based adhesives are a promising alternative, reported to have good cytocompatibility and favorable immunogenicity. A photo-cross-linkable hydrogel based on chitosan is proposed as a new adhesive for peripheral nerve anastomosis. Two Az-chitosans were synthesized by conjugating 4-azidobenzoic acid with low (LMW, 15 kDa) and high (HMW, 50-190 kDa) molecular weight chitosans. These solutions formed a hydrogel in less than 1 min under UV light. The LMW Az-chitosan was more tightly cross-linked than the HMW variant, undergoing significantly less swelling and possessing a higher rheological storage modulus, and both Az-chitosan gels were stiffer than commercial fibrin glue. Severed nerves repaired by Az-chitosan adhesives tolerated longitudinal forces comparable or superior to fibrin glue. Adhesive exposure to intact nerves and neural cell culture showed both Az-chitosans to be nontoxic in the acute (minutes) and chronic (days) time frames. These results demonstrate that Az-chitosan hydrogels are cytocompatible and mechanically suitable for use as bioadhesives in peripheral neurosurgeries.

  7. Preparation of alginate coated chitosan microparticles for vaccine delivery

    Directory of Open Access Journals (Sweden)

    Wei YuQuan

    2008-11-01

    Full Text Available Abstract Background Absorption of antigens onto chitosan microparticles via electrostatic interaction is a common and relatively mild process suitable for mucosal vaccine. In order to increase the stability of antigens and prevent an immediate desorption of antigens from chitosan carriers in gastrointestinal tract, coating onto BSA loaded chitosan microparticles with sodium alginate was performed by layer-by-layer technology to meet the requirement of mucosal vaccine. Results The prepared alginate coated BSA loaded chitosan microparticles had loading efficiency (LE of 60% and loading capacity (LC of 6% with mean diameter of about 1 μm. When the weight ratio of alginate/chitosan microparticles was greater than 2, the stable system could be obtained. The rapid charge inversion of BSA loaded chitosan microparticles (from +27 mv to -27.8 mv was observed during the coating procedure which indicated the presence of alginate layer on the chitosan microparticles surfaces. According to the results obtained by scanning electron microscopy (SEM, the core-shell structure of BSA loaded chitosan microparticles was observed. Meanwhile, in vitro release study indicated that the initial burst release of BSA from alginate coated chitosan microparticles was lower than that observed from uncoated chitosan microparticles (40% in 8 h vs. about 84% in 0.5 h. SDS-polyacrylamide gel electrophoresis (SDS-PAGE assay showed that alginate coating onto chitosan microparticles could effectively protect the BSA from degradation or hydrolysis in acidic condition for at least 2 h. The structural integrity of alginate modified chitosan microparticles incubated in PBS for 24 h was investigated by FTIR. Conclusion The prepared alginate coated chitosan microparticles, with mean diameter of about 1 μm, was suitable for oral mucosal vaccine. Moreover, alginate coating onto the surface of chitosan microparticles could modulate the release behavior of BSA from alginate coated chitosan

  8. Chitosan-Based Polymer Blends: Current Status and applications

    International Nuclear Information System (INIS)

    Hefian, E.A.E.; Nasef, M.M.

    2014-01-01

    This paper reviews the latest developments in chitosan-based blends and their potential applications in various fields. Various blends together with other derivatives, such as composites and graft copolymers, have been developed to overcome chitosans disadvantages, including poor mechanical properties and to improve its functionality towards specific applications. The progress made in blending chitosan with synthetic and natural polymers is presented. The versatility and unique characteristics, such as hydrophilicity, film-forming ability, biodegradability, biocompatibility, antibacterial activity and non-toxicity of chitosan has contributed to the successful development of various blends for medical, pharmaceutical, agricultural and environmental applications. (author)

  9. Physicochemical Characterization of Biopolymer Chitosan Extracted from Shrimp Shells

    Directory of Open Access Journals (Sweden)

    Nezamaddin Mengelizadeh

    2015-02-01

    Full Text Available Chitosan is a deacetylated derivative of chitin, which is a naturally abundant mucopolysaccharide, supporting the matter of crustaceans, insects, and fungi. Because of its unique properties, such as non-toxicity, biodegradability, and biocompatibility, chitosan has a wide range of applications in various fields. The objective of the present work is to extract the polymer chitosan from Persian Gulf shrimp shells. In order to determine the physicochemical characteristics of the extracted chitosan, degree of deacetylation, molecular weight, water and fat binding capacities extraction rate, and apparent viscosity were measured using a variety of techniques including viscometry, weight measurement method and Fourier transform infrared spectroscopy (FTIR. The results of the study of the physicochemical properties, molecular weight (6.7×105 Da, degree of deacetylation (57%, ash content as well as yield (0.5% of the prepared chitosan indicated that shrimp processing wastes (shrimp shells are a good source of chitosan. The water binding capacity (521% and fat binding capacity (327% of the prepared chitosan are in good agreement with the other studies. The elemental analysis showed the C, H and N contents of 35.92%, 7.02%, and 8.66%, respectively. In this study, the antimicrobial activity of chitosan was evaluated against Staphylococcus aureus and Escherichia coli. The results indicated the high potential of chitosan as an antibacterial agent. Moreover, the results of the study indicated that shrimp shells are a rich source of chitin as 25.21% of the shell’s dry weight.

  10. Hydrothermally treated chitosan hydrogel loaded with copper and zinc particles as a potential micro-nutrient based antimicrobial feed additive

    Directory of Open Access Journals (Sweden)

    Parthiban eRajasekaran

    2015-11-01

    Full Text Available Large-scale use of antibiotics in food animal farms as growth promoters is considered as one of the driving factors behind increasing incidence of microbial resistance. Several alternatives are under investigation to reduce the amount of total antibiotics used in order to avoid any potential transmission of drug resistant microbes to humans through food chain. Copper sulfate and zinc oxide salts are used as feed supplement as they exhibit antimicrobial properties in addition to being micronutrients. However, higher dosage of copper and zinc (often needed for growth promoting effect to animals is not advisable because of potential environmental toxicity arising from excreta. Innovative strategies are needed to utilize the complete potential of trace minerals as growth promoting feed supplements. To this end, we describe here the development and preliminary characterization of hydrothermally treated chitosan as a delivery vehicle for copper and zinc nanoparticles that could act as a micronutrient based antimicrobial feed supplement. Material characterization studies showed that hydrothermal treatment makes a chitosan hydrogel that re-arranged to capture the copper and zinc metal particles. Systemic antimicrobial assays showed that this chitosan biopolymer matrix embedded with copper (57.6 μg/ml and zinc (800 μg/ml reduced the load of model gut-bacteria (target organisms of growth promoting antibiotics such as Escherichia coli, Enterococcus faecalis, Staphylococcus aureus and Lactobacillus fermentum under in vitro conditions. Particularly, the chitosan/copper/zinc hydrogel exhibited significantly higher antimicrobial effect against L. fermentum, one of the primary targets of antibiotic growth promoters. Additionally, the chitosan matrix ameliorated the cytotoxicity levels of metal supplements when screened against a murine macrophage cell line RAW 264.7 and in TE-71, a murine thymic epithelial cell line. In this proof of concept study, we show

  11. Microencapsulation of norfloxacin in chitosan/chitosan oligosaccharides and its application in shrimp culture.

    Science.gov (United States)

    Lian, Ziru; Pan, Rong; Wang, Jiangtao

    2016-11-01

    Norfloxacin chitosan/chitosan oligosaccharide microcapsules (NCCM) were prepared by emulsion-chemical crosslinking method. The characteristics of obtained microcapsules were evaluated by scanning electron microscopy, Fourier transform infrared spectroscopy and release experiments. Cumulative release profile of norfloxacin from the chitosan microcapsules in natural seawater was measured and the controlled release of drugs was at a uniform rate in 48h. The chitosan microcapsules were applied onto the antibacterial study of the shrimp culture in natural seawater. It is observed that the seawater in the NCCM added groups was relatively clear and the biomass of Vibrio increased slowly in contrast to the control and norfloxacin groups. The inhibition rate of Vibrio in norfloxacin groups obvioursly decreased after the 5 th day, whereas, it remained high and stable during experiment period in NCCM groups. The results showed that the chitosan microcapsules as release materials have excellent antibacterial effects on Vibrio in the farming of Penaeus vannamei Boone. The controlled release could obviously reduce dosage of antibiotics and delivery times, and effectively improve the utilization rate of norfloxacin drugs for shrimps. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Synthesis and characterization of Ag2S decorated chitosan nanocomposites and chitosan nanofibers for removal of lincosamides antibiotic.

    Science.gov (United States)

    Gupta, Vinod Kumar; Fakhri, Ali; Agarwal, Shilpi; Azad, Mona

    2017-10-01

    We report the synthesis of Ag 2 S-Chitosan nanocomposites and Ag 2 S-chitosan nanohybrids as performance adsorbents for Lincosamides such as Clindamycin antibiotic removal. Isotherms and kinetic studies were determined to understand the adsorption behavior both two adsorbent. At low adsorbent dose, removals are increased in the adsorption process, and performance is better with Ag 2 S-chitosan nanohybrids due to the special surface area increased. The average sizes and surface area of Ag 2 S-Chitosan nanocomposites and Ag 2 S-chitosan nanohybrids were found as 50nm, 70nm and 180.18, 238.24m 2 g -1 , respectively. In particular, Ag 2 S-Chitosan nanocomposites and Ag 2 S-chitosan nanohybrids show high maximum Clindamycin adsorption capacity (q max ) of 153.21, and 181.28mgg -1 , respectively. More strikingly, Ag 2 S-Chitosan nanocomposites and Ag 2 S-chitosan nanohybrids are also demonstrated to nearly completely remove Clindamycin from drinking water. The excellent adsorption performance along with their cost effective, convenient synthesis makes this range of adsorbents highly promising for commercial applications in drinking water and wastewater treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Application of Ferriferous Oxide Modified by Chitosan in Gene Delivery

    Directory of Open Access Journals (Sweden)

    Yu Kuang

    2012-01-01

    Full Text Available 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 of CTS-Fe3O4 and PEG-Fe3O4 was about 20 mv and 0 mv, respectively. The controlled release of DNA from the CTS-Fe3O4 nanoparticles was observed. Concurrently, a desired Fe3O4 concentration of less than 2 mM was verified as safe by means of a cytotoxicity test in vitro. Presence of the permanent magnetic field significantly increased the transfection efficiency. Furthermore, the passive target property and safety of magnetic nanoparticles were also demonstrated in an in vivo test. The novel gene delivery system was proved to be an effective tool required for future target expression and gene therapy in vivo.

  14. New sizing agents and flocculants derived from chitosan

    International Nuclear Information System (INIS)

    Hebeish, A.; Higay, A.; El-Shafei, A.

    2005-01-01

    Novel approaches for development of new textile sizing agents and flocculants were undertaken. One of these approaches is based on acid hydrolysis of chitosan and the other involves its carboxy methylation. Characterization of the hydrolyzed chitosan was performed through monitoring nitrogen content and apparent viscosity, while carboxymethyl chitosan was analyzed for degree of substitution (DS) along with apparent viscosity. Factors affecting both hydrolysis and carboxy methylation were investigated. The nitrogen content and apparent viscosity of chitosan decrease variably by increasing HCl concentration as well as time and temperature of hydrolysis. On the other hand, the DS of carboxymethyl chitosan increases by increasing the concentration of both sodium hydroxide and monochloroacetic acid and similarly increases by prolonging the duration and raising the temperature of carboxy methylation; in contrast with apparent viscosity which is inversely related to these parameters. Aqueous solutions of hydrolyzed chitosan or carboxymethyl chitosan were applied to light cotton fabric with a view to envision the technical feasibility of such water soluble chitosan for textile sizing. The size add-on on the light fabric is directly related to the concentration of the hydrolyzed or carboxymethyl chitosan in the sizing solution and so does the apparent viscosity of the latter. Hundred percent size removals could be achieved with the hydrolyzed chitosan irrespective or the size solution concentration provided that the latter is not less than 8%. Different situation is encountered with carboxymethyl chitosan where the percent size removal increase from 81% to 95% by increasing its concentration in the sizing solution from 5 % to 15%. Drying the sized fabric at 80 degree C for 5 minutes or 120 degree C for 3 minutes has practically no effect on percent size removal. The same holds true for heat treatment of the sized fabric at higher temperatures (up to 160 degree C) for longer

  15. Immobilization of catalase on chitosan and amino acid- modified chitosan beads.

    Science.gov (United States)

    Başak, Esra; Aydemir, Tülin

    2013-08-01

    Bovine liver catalase was covalently immobilized onto amino acid-modified chitosan beads. The beads were characterized with SEM, FTIR, TGA and the effects of immobilization on optimum pH and temperature, thermostability, reusability were evaluated. Immobilized catalase showed the maximal enzyme activity at pH 7.0 at 30°C. The kinetic parameters, Km and Vmax, for immobilized catalase on alanine-chitosan beads and lysine-chitosan beads were estimated to be 25.67 mM, 27 mM and 201.39 μmol H2O2/min, 197.50 μmol H2O2/min, respectively. The activity of the immobilized catalase on Ala-CB and Lys-CB retained 40% of its high initial activity after 100 times of reuse.

  16. Physicochemical and immunological characterization of chitosan-coated bacteriophage nanoparticles for in vivo mycotoxin modeling.

    Science.gov (United States)

    de Andrade, Carla Yoko Tanikawa; Yamanaka, Isabel; Schlichta, Laís S; Silva, Sabrina Karim; Picheth, Guilherme F; Caron, Luiz Felipe; de Moura, Juliana; de Freitas, Rilton Alves; Alvarenga, Larissa Magalhães

    2018-04-01

    To propose a novel modeling of aflatoxin immunization and surrogate toxin conjugate from AFB1 vaccines, an immunogen based on the mimotope, (i.e. a peptide-displayed phage that mimics aflatoxins epitope without toxin hazards) was designed. The recombinant phage 3P30 was identified by phage display technology and exhibited the ability to bind, dose dependent, specifically to its cognate target - anti-AFB1 antibody. In immunization assay, the phage-displayed mimotope and its peptide chemically synthesized were able to induce specific anti-AFB1 antibodies, indicating the proof of concept for aflatoxin mimicry. Furthermore, the phage 3P30 was homogeneously coated with chitosan, which also provided a tridimensional matrix network for mucosal delivery. After intranasal immunization, chitosan coated phages improved specific immunogenicity compared to the free antigen. It can be concluded that affinity-selected phage may contribute to the rational design of epitope-based vaccines in a prospectus for the control of aflatoxins and possibly other mycotoxins, and that chitosan coating improved the vectorization of the vaccine by the mucosal route. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Paraquat-loaded alginate/chitosan nanoparticles: Preparation, characterization and soil sorption studies

    Energy Technology Data Exchange (ETDEWEB)

    Santos Silva, Mariana dos; Sgarbi Cocenza, Daniela [Department of Environmental Engineering, Sao Paulo State University - UNESP, Avenida Tres de Marco, No. 511, CEP 18087-180, Sorocaba, SP (Brazil); Grillo, Renato; Silva de Melo, Nathalie Ferreira [Department of Environmental Engineering, Sao Paulo State University - UNESP, Avenida Tres de Marco, No. 511, CEP 18087-180, Sorocaba, SP (Brazil); Department of Biochemistry, Institute of Biology, State University of Campinas - UNICAMP, Campinas, SP (Brazil); Tonello, Paulo Sergio [Department of Environmental Engineering, Sao Paulo State University - UNESP, Avenida Tres de Marco, No. 511, CEP 18087-180, Sorocaba, SP (Brazil); Camargo de Oliveira, Luciana [Department of Chemistry, UFSCAr, Campus Sorocaba, SP (Brazil); Lopes Cassimiro, Douglas [Institute of Chemistry, Sao Paulo State University - UNESP, Araraquara, SP (Brazil); Rosa, Andre Henrique [Department of Environmental Engineering, Sao Paulo State University - UNESP, Avenida Tres de Marco, No. 511, CEP 18087-180, Sorocaba, SP (Brazil); Fernandes Fraceto, Leonardo, E-mail: leonardo@sorocaba.unesp.br [Department of Environmental Engineering, Sao Paulo State University - UNESP, Avenida Tres de Marco, No. 511, CEP 18087-180, Sorocaba, SP (Brazil); Department of Biochemistry, Institute of Biology, State University of Campinas - UNICAMP, Campinas, SP (Brazil)

    2011-06-15

    Agrochemicals are amongst the contaminants most widely encountered in surface and subterranean hydrological systems. They comprise a variety of molecules, with properties that confer differing degrees of persistence and mobility in the environment, as well as different toxic, carcinogenic, mutagenic and teratogenic potentials, which can affect non-target organisms including man. In this work, alginate/chitosan nanoparticles were prepared as a carrier system for the herbicide paraquat. The preparation and physico-chemical characterization of the nanoparticles was followed by evaluation of zeta potential, pH, size and polydispersion. The techniques employed included transmission electron microscopy, differential scanning calorimetry and Fourier transform infrared spectroscopy. The formulation presented a size distribution of 635 {+-} 12 nm, polydispersion of 0.518, zeta potential of -22.8 {+-} 2.3 mV and association efficiency of 74.2%. There were significant differences between the release profiles of free paraquat and the herbicide associated with the alginate/chitosan nanoparticles. Tests showed that soil sorption of paraquat, either free or associated with the nanoparticles, was dependent on the quantity of organic matter present. The results presented in this work show that association of paraquat with alginate/chitosan nanoparticles alters the release profile of the herbicide, as well as its interaction with the soil, indicating that this system could be an effective means of reducing negative impacts caused by paraquat.

  18. Multimodal in vivo MRI and NIRF imaging of bladder tumor using peptide conjugated glycol chitosan nanoparticles

    Science.gov (United States)

    Key, Jaehong; Dhawan, Deepika; Knapp, Deborah W.; Kim, Kwangmeyung; Kwon, Ick Chan; Choi, Kuiwon; Leary, James F.

    2012-03-01

    Exact detection and complete removal of cancer is a key point to minimize cancer recurrence. However, it is currently very difficult to detect small tumors inside human body and continuously monitor tumors using a non-invasive imaging modality. Presently, positron emission tomography (PET) can provide the most sensitive cancer images in the human body. However, PET imaging has very limited imaging time because they typically use isotopes with short halflives. PET imaging cannot also visualize anatomical information. Magnetic resonance imaging (MRI) can provide highresolution images inside the body but it has a low sensitivity, so MRI contrast agents are necessary to enhance the contrast of tumor. Near infrared fluorescent (NIRF) imaging has a good sensitivity to visualize tumor using optical probes, but it has a very limited tissue penetration depth. Therefore, we developed multi-modality nanoparticles for MRI based diagnosis and NIRF imaging based surgery of cancer. We utilized glycol chitosan of 350 nm as a vehicle for MRI contrast agents and NIRF probes. The glycol chitosan nanoparticles were conjugated with NIRF dye, Cy5.5 and bladder cancer targeting peptides to increase the internalization of cancer. For MR contrast effects, iron oxide based 22 nm nanocubes were physically loaded into the glycol chitosan nanoparticles. The nanoparticles were characterized and evaluated in bladder tumor bearing mice. Our study suggests the potential of our nanoparticles by both MRI and NIRF imaging for tumor diagnosis and real-time NIRF image-guided tumor surgery.

  19. Heavy metals adsorption by novel EDTA-modified chitosan-silica hybrid materials.

    Science.gov (United States)

    Repo, Eveliina; Warchoł, Jolanta K; Bhatnagar, Amit; Sillanpää, Mika

    2011-06-01

    Novel adsorbents were synthesized by functionalizing chitosan-silica hybrid materials with (ethylenediaminetetraacetic acid) EDTA ligands. The synthesized adsorbents were found to combine the advantages of both silica gel (high surface area, porosity, rigid structure) and chitosan (surface functionality). The Adsorption potential of hybrid materials was investigated using Co(II), Ni(II), Cd(II), and Pb(II) as target metals by varying experimental conditions such as pH, contact time, and initial metal concentration. The kinetic results revealed that the pore diffusion process played a key role in adsorption kinetics, which might be attributed to the porous structure of synthesized adsorbents. The obtained maximum adsorption capacities of the hybrid materials for the metal ions ranged from 0.25 to 0.63 mmol/g under the studied experimental conditions. The adsorbent with the highest chitosan content showed the best adsorption efficiency. Bi-Langmuir and Sips isotherm model fitting to experimental data suggested the surface heterogeneity of the prepared adsorbents. In multimetal solutions, the hybrid adsorbents showed the highest affinity toward Pb(II). Copyright © 2011 Elsevier Inc. All rights reserved.

  20. 3D porous chitosan scaffolds suit survival and neural differentiation of dental pulp stem cells.

    Science.gov (United States)

    Feng, Xingmei; Lu, Xiaohui; Huang, Dan; Xing, Jing; Feng, Guijuan; Jin, Guohua; Yi, Xin; Li, Liren; Lu, Yuanzhou; Nie, Dekang; Chen, Xiang; Zhang, Lei; Gu, Zhifeng; Zhang, Xinhua

    2014-08-01

    A key aspect of cell replacement therapy in brain injury treatment is construction of a suitable biomaterial scaffold that can effectively carry and transport the therapeutic cells to the target area. In the present study, we created small 3D porous chitosan scaffolds through freeze-drying, and showed that these can support and enhance the differentiation of dental pulp stem cells (DPSCs) to nerve cells in vitro. The DPSCs were collected from the dental pulp of adult human third molars. At a swelling rate of ~84.33 ± 10.92 %, the scaffold displayed high porosity and interconnectivity of pores, as revealed by SEM. Cell counting kit-8 assay established the biocompatibility of the chitosan scaffold, supporting the growth and survival of DPSCs. The successful neural differentiation of DPSCs was assayed by RT-PCR, western blotting, and immunofluorescence. We found that the scaffold-attached DPSCs showed high expression of Nestin that decreased sharply following induction of differentiation. Exposure to the differentiation media also increased the expression of neural molecular markers Microtubule-associated protein 2, glial fibrillary acidic protein, and 2',3'-cyclic nucleotide phosphodiesterase. This study demonstrates that the granular 3D chitosan scaffolds are non-cytotoxic, biocompatible, and provide a conducive and favorable micro-environment for attachment, survival, and neural differentiation of DPSCs. These scaffolds have enormous potential to facilitate future advances in treatment of brain injury.

  1. Radiolysis of chitosan derivatives exhibiting antimutagenic activity

    International Nuclear Information System (INIS)

    Aleksandrova, V.A.; Kuzina, S.I.; Shilova, I.A.; Mikhajlov, A.I.

    2006-01-01

    The radiolysis of antimutagens extracted from natural biopolymer chitosan was studied by the EPR. The radiolysis of test samples of biopolymers and gallic acid was performed in vacuum at 77 K using a 60 Co γ-radiation source, with radiation doses 50 kGy. It was shown that addition of gallic acid (2 mol %) to quaternized chitosan results in a 2.5-fold decrease in the radiation-chemical yield of radicals and a nearly complete inhibition of the formation of ion radicals. Gallic acid units likely play the role of a stabilizer that protects the polycation from radiation damage and, hence, the structure of the cationogenic units from changes, thereby improving the antimutagenic properties of the system [ru

  2. X-ray diffraction studies of chitosan acetate-based polymer electrolytes

    International Nuclear Information System (INIS)

    Osman, Z.; Ibrahim, Z.A.; Abdul Kariem Arof

    2002-01-01

    Chitosan is the product when partially deacetylated chitin dissolves in dilute acetic acid. This paper presents the x-ray diffraction patterns of chitosan acetate, plasticised chitosan acetate and plasticised-salted chitosan acetate films. The results show that the chitosan acetate based polymer electrolyte films are not completely amorphous but it is partially crystalline. X-ray diffraction study also confirms the occurrence of the complexation between chitosan and the salt and the interaction between salt and plasticizer. The salt-chitosan interaction is clearly justified by infrared spectroscopy. (Author)

  3. Preparation and characterization of β-cyclodextrin grafted N-maleoyl chitosan nanoparticles for drug delivery

    Directory of Open Access Journals (Sweden)

    Xinyu Hou

    2017-11-01

    Full Text Available β-cyclodextrin (CD grafted N-maleoyl chitosan (CD-g-NMCS with two different degrees of substitution (DS of N-maleoyl (DS = 21.2% and 30.5% were synthesized from maleic anhydride and chitosan bearing pendant cyclodextrin (CD-g-CS. CD-g-NMCS based nanoparticles were prepared via an ionic gelation method together with chitosan and CD-g-CS nanoparticles. The size and zeta potential of prepared CD-g-NMCS nanoparticles were 179.2~274.0 nm and 36.2~42.4 mV, respectively. In vitro stability test indicated that CD-g-NMCS nanoparticles were more stable in phosphate-buffered saline compared with chitosan nanoparticles. Moreover, a poorly water-soluble drug, ketoprofen (KTP, was selected as a model drug to study the obtained nanoparticle's potentials as drug delivery carriers. The drug loading efficiency of CD-g-NMCS20 nanoparticles were 14.8% for KTP. MTT assay showed that KTP loaded CD-g-NMCS nanoparticles were safe drug carriers. Notably, in vitro drug release studies showed that KTP was released in a sustained-release manner for the nanoparticles. The pharmacokinetic of drug loaded CD-g-NMCS20 nanoparticles were evaluated in rats after intravenous administration. The results of studies revealed that, compared with free KTP, KTP loaded CD-g-NMCS20 nanoparticles exhibited a significant increase in AUC0→24h and mean residence time by 6.6-fold and 2.9-fold, respectively. Therefore, CD-g-NMCS nanoparticles could be used as a novel promising nanoparticle-based drug delivery system for sustained release of poorly water-soluble drugs. The carboxylic acid groups of the CD-g-NMCS molecule provide convenient sites for further structural modifications including introduction of tissue- or disease- specific targeting groups.

  4. Chitosan films and blends for packaging material.

    Science.gov (United States)

    van den Broek, Lambertus A M; Knoop, Rutger J I; Kappen, Frans H J; Boeriu, Carmen G

    2015-02-13

    An increased interest for hygiene in everyday life as well as in food, feed and medical issues lead to a strong interest in films and blends to prevent the growth and accumulation of harmful bacteria. A growing trend is to use synthetic and natural antimicrobial polymers, to provide non-migratory and non-depleting protection agents for application in films, coatings and packaging. In food packaging, antimicrobial effects add up to the barrier properties of the materials, to increase the shelf life and product quality. Chitosan is a natural bioactive polysaccharide with intrinsic antimicrobial activity and, due to its exceptional physicochemical properties imparted by the polysaccharide backbone, has been recognized as a natural alternative to chemically synthesized antimicrobial polymers. This, associated with the increasing preference for biofunctional materials from renewable resources, resulted in a significant interest on the potential for application of chitosan in packaging materials. In this review we describe the latest developments of chitosan films and blends as packaging material. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. In vitro osteoclastogenesis on textile chitosan scaffold

    Directory of Open Access Journals (Sweden)

    C Heinemann

    2010-02-01

    Full Text Available Textile chitosan fibre scaffolds were evaluated in terms of interaction with osteoclast-like cells, derived from human primary monocytes. Part of the scaffolds was further modified by coating with fibrillar collagen type I in order to make the surface biocompatible. Monocytes were cultured directly on the scaffolds in the presence of macrophage colony stimulating factor (M-CSF and receptor activator of nuclear factor kappaB ligand (RANKL for up to 18 days. Confocal laser scanning microscopy (CLSM as well as scanning electron microscopy (SEM revealed the formation of multinuclear osteoclast-like cells on both the raw chitosan fibres and the collagen-coated scaffolds. The modified surface supported the osteoclastogenesis. Differentiation towards the osteoclastic lineage was confirmed by the microscopic detection of cathepsin K, tartrate resistant acid phosphatase (TRAP, acidic compartments using 3-(2,4-dinitroanillino-3’-amino-N-methyldipropylamine (DAMP, immunological detection of TRAP isoform 5b, and analysis of gene expression of the osteoclastic markers TRAP, cathepsin K, vitronectin receptor, and calcitonin receptor using reverse transcription-polymerase chain reaction (RT-PCR. The feature of the collagen-coated but also of the raw chitosan fibre scaffolds to support attachment and differentiation of human monocytes facilitates cell-induced material resorption – one main requirement for successful bone tissue engineering.

  6. Poly(acrylonitrile)chitosan composite membranes for urease immobilization.

    Science.gov (United States)

    Gabrovska, Katya; Georgieva, Aneliya; Godjevargova, Tzonka; Stoilova, Olya; Manolova, Nevena

    2007-05-10

    (Poly)acrylonitrile/chitosan (PANCHI) composite membranes were prepared. The chitosan layer was deposited on the surface as well as on the pore walls of the base membrane. This resulted in the reduction of the pore size of the membrane and in an increase of their hydrophilicity. The pore structure of PAN and PANCHI membranes were determined by TEM and SEM analyses. It was found that the average size of the pore under a selective layer base PAN membrane is 7 microm, while the membrane coated with 0.25% chitosan shows a reduced pore size--small or equal to 5 microm and with 0.35% chitosan--about 4 microm. The amounts of the functional groups, the degree of hydrophilicity and transport characteristics of PAN/Chitosan composite membranes were determined. Urease was covalently immobilized onto all kinds of PAN/chitosan composite membranes using glutaraldehyde. Both the amount of bound protein and relative activity of immobilized urease were measured. The highest activity (94%) was measured for urease bound to PANCHI2 membranes (0.25% chitosan). The basic characteristics (pH(opt), pH(stability), T(opt), T(stability), heat inactivation and storage stability) of immobilized urease were determined. The obtained results show that the poly(acrylonitrile)chitosan composite membranes are suitable for enzyme immobilization.

  7. Alkyl chitosan film-high strength, functional biomaterials.

    Science.gov (United States)

    Lu, Li; Xing, Cao; Xin, Shen; Shitao, Yu; Feng, Su; Shiwei, Liu; Fusheng, Liu; Congxia, Xie

    2017-11-01

    Biofilm with strong tensile strength is a topic item in the area of tissue engineering, medicine engineering, and so forth. Here we introduced an alkyl chitosan film with strong tensile strength and its possibility for an absorbable anticoagulation material in vivo was tested in the series of blood test, such as dynamic coagulation time, plasma recalcification time and hemolysis. Alkyl chitosan film was a better biomaterial than traditional chitosan film in the anticoagulation, tissue compatibility and cell compatibility. The unique trait of alkyl chitosan film may be for its greater contact angle and hydrophobicity ability to reduce the adsorption capacity for the blood component and the activity of fibrinolytic enzymes, enhance the antibacterial capacity than chitosan film. Moreover, none of chitosan film or butyl chitosan film exhibited quick inflammation or other disadvantage and degraded quickly by implanted test. Therefore, Alkyl chitosan film is of prospective properties as an implantable, absorbable agent for tissue heals, and this material need further research. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3034-3041, 2017. © 2017 Wiley Periodicals, Inc.

  8. Extraction and characterization of chitin and chitosan from Nigerian ...

    African Journals Online (AJOL)

    Chitin was synthesized from Nigerian brown shrimps by a chemical process involving demineralization and deproteinisation. Deacetylation of the chitin was conducted to obtain Chitosan. The chitin and chitosan were characterized using FTIR, XRD and SEM. Proximate and elemental analysis were also conducted.

  9. Chitosan Based Self-Assembled Nanoparticles in Drug Delivery

    Directory of Open Access Journals (Sweden)

    Javier Pérez Quiñones

    2018-02-01

    Full Text Available Chitosan is a cationic polysaccharide that is usually obtained by alkaline deacetylation of chitin poly(N-acetylglucosamine. It is biocompatible, biodegradable, mucoadhesive, and non-toxic. These excellent biological properties make chitosan a good candidate for a platform in developing drug delivery systems having improved biodistribution, increased specificity and sensitivity, and reduced pharmacological toxicity. In particular, chitosan nanoparticles are found to be appropriate for non-invasive routes of drug administration: oral, nasal, pulmonary and ocular routes. These applications are facilitated by the absorption-enhancing effect of chitosan. Many procedures for obtaining chitosan nanoparticles have been proposed. Particularly, the introduction of hydrophobic moieties into chitosan molecules by grafting to generate a hydrophobic-hydrophilic balance promoting self-assembly is a current and appealing approach. The grafting agent can be a hydrophobic moiety forming micelles that can entrap lipophilic drugs or it can be the drug itself. Another suitable way to generate self-assembled chitosan nanoparticles is through the formation of polyelectrolyte complexes with polyanions. This paper reviews the main approaches for preparing chitosan nanoparticles by self-assembly through both procedures, and illustrates the state of the art of their application in drug delivery.

  10. Amphiphilic chitosan derivatives as carrier agents for rotenone

    Science.gov (United States)

    Kamari, Azlan; Aljafree, Nurul Farhana Ahmad

    2017-08-01

    In the present study, the feasibility of amphiphilic chitosan derivatives, namely oleoyl carboxymethyl chitosan (OCMCs), N,N-dimethylhexadecyl carboxymethyl chitosan (DCMCs) and deoxycholic acid carboxymethyl chitosan (DACMCs) as carrier agents for rotenone in water-insoluble pesticide formulations was investigated. Fourier Transform Infrared (FTIR) Spectrometer, CHN-O Elemental Analyser (CHN-O) and Transmission Electron Microscope (TEM) were used to characterise amphiphilic chitosan derivatives. The critical micelle concentration (CMC) of amphiphilic chitosan derivatives was determined using a Fluorescence Spectrometer. A High Performance Liquid Chromatography (HPLC) was used to determine the ability of OCMCs, DCMCs and DACMCs to load and release rotenone in an in vitro system. Based on TEM analysis, results have shown that amphiphilic chitosan derivatives formed self-assembly and exhibited spherical shape. The CMC values determined for OCMCs, DCMCs and DACMCs were 0.093, 0.098 and 0.468 mg/mL, respectively. The encapsulation efficiency (EE) values for the materials were more than 97.0%, meanwhile the loading capacity (LC) values were greater than 0.90%. OCMCs, DCMCs and DACMCs micelles exhibited an excellent ability to control the release of rotenone, of which 90.0% of rotenone was released within 40 to 52 h. In conclusion, OCMCs, DCMCs and DACMCs possess several key features to act as effective carrier agents for rotenone. Overall, amphiphilic chitosan derivatives produced in this study were successfully increased the solubility of rotenone by 49.0 times higher than free rotenone.

  11. Thermal decomposition of natural polysaccharides: Chitin and chitosan

    Directory of Open Access Journals (Sweden)

    Kuchina Yu.A.

    2015-03-01

    Full Text Available The results of the thermal analysis of shrimp’s chitin and chitosan have been presented (samples of polysaccharide differed by the deacetylation degree have been studied. The thermal analysis has been carried out by differential thermogravimetry and differential scanning calorimetry. Activation energy of process of chitin and chitosan thermal destruction has been calculated

  12. Studies on electrospun nylon-6/chitosan complex nanofiber interactions

    International Nuclear Information System (INIS)

    Zhang Haitao; Li Shubai; Branford White, Christopher J.; Ning Xin; Nie Huali; Zhu Limin

    2009-01-01

    Composite membranes of nylon-6/chitosan nanofibers with different weight ratio of nylon-6 to chitosan were fabricated successfully using electrospinning. Morphologies of the nanofibers were investigated by scanning electron microscopy (SEM) and the intermolecular interactions of the nylon-6/chitosan complex were evaluated by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC) as well as mechanical testing. We found that morphology and diameter of the nanofibers were influenced by the concentration of the solution and weight ratio of the blending component materials. Furthermore FT-IR analyses on interactions between components demonstrated an IR band frequency shift that appeared to be dependent on the amount of chitosan in the complex. Observations from XRD and DSC suggested that a new fraction of γ phase crystals appeared and increased with the increasing content of chitosan in blends, this indicated that intermolecular interactions occurred between nylon-6 and chitosan. Results from performance data in mechanical showed that intermolecular interactions varied with varying chitosan content in the fibers. It was concluded that a new composite product was created and the stability of this system was attributed to strong new interactions such as hydrogen bond formation between the nylon-6 polymers and chitosan structures.

  13. Chitosan from shrimp shell ( Crangon crangon ) and fish scales ...

    African Journals Online (AJOL)

    Chitosan is a naturally available biopolymer. It has been prepared by alkaline N deacetylation process of shrimp (Crangon crangon) chitin and fish (Labeorohita) chitin. The physico-chemical properties such as the degree of deacetylation (DD), solubility, water binding capacity, fat binding capacity and chitosan yield have ...

  14. Depolymerization of chitosan by enzymes from the digestive tract of ...

    African Journals Online (AJOL)

    A complex of enzymes was isolated in a preparation derived from the digestive tract of sea cucumber, Stichopus japonicus. Hydrolysis of chitosan using this enzyme preparation decreased its molecular weight (Mw), increased its water solubility and produced water-soluble chitosan (WSC). The conditions for hydrolysis were ...

  15. Inhibitory effect of chitosan oligosaccharide on human hepatoma ...

    African Journals Online (AJOL)

    Background: Chitosan oligosaccharide, the degradation products of chitin, was reported to have a wide range of physiological functions and biological activities. In this study, we explored the inhibitory effect of Chitosan oligosaccharide on human hepatoma cells. Materials and Methods: MTT assay was applied to detect cell ...

  16. Role of Glycol Chitosan-incorporated Ursolic Acid Nanoparticles in ...

    African Journals Online (AJOL)

    Purpose: To investigate the effect of ursolic acid (UA)-incorporated glycol chitosan (GC) nanoparticles on inhibition of human osteosarcoma. Methods: U2OS and Saos-2 osteosarcoma cells were transfected with ursolic acid (UA) incorporated glycol chitosan (GC) nanoparticles. Ultraviolet (UV) spectrophotometry was used ...

  17. Plasticized chitosan/polyolefin films produced by extrusion.

    Science.gov (United States)

    Matet, Marie; Heuzey, Marie-Claude; Ajji, Abdellah; Sarazin, Pierre

    2015-03-06

    Plasticized chitosan and polyethylene blends were produced through a single-pass extrusion process. Using a twin-screw extruder, chitosan plasticization was achieved in the presence of an acetic acid solution and glycerol, and directly mixed with metallocene polyethylene, mPE, to produce a masterbatch. Different dilutions of the masterbatch (2, 5 and 10 wt% of plasticized chitosan), in the presence of ethylene vinyl acetate, EVA, were subsequently achieved in single screw film extrusion. Very small plasticized chitosan domains (number average diameter <5 μm) were visible in the polymeric matrix. The resulting films presented a brown color and increasing haze with chitosan plasticized content. Mechanical properties of the mPE films were affected by the presence of plasticized chitosan, but improvement was observed as a result of some compatibility between mPE and chitosan in the presence of EVA. Finally the incorporation of plasticized chitosan affected mPE water vapor permeability while oxygen permeability remained constant. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Formulation and Evaluation of Glutaraldehyde-Crosslinked Chitosan ...

    African Journals Online (AJOL)

    Tropical Journal of Pharmaceutical Research is indexed by Science Citation Index (Purpose: Toformulate glutaraldehyde-cross-linked chitosan-based microparticles and evaluate its suitability for the delivery of ibuprofen, a BCS class II drug. Methods: Ibuprofen-loaded chitosan microparticles were prepared by ...

  19. Formulation of chitosan-based ciprofloxacin and diclofenac film for ...

    African Journals Online (AJOL)

    Purpose: This study was designed to develop and evaluate chitosan films containing ciprofloxacin and diclofenac sodium for the topical treatment of periodontitis. Methods: Chitosan films containing ciprofloxacin alone and in combination with diclofenac sodium were prepared by solvent casting method. Some of the ...

  20. Preparation and characterization of blends containing silk fibroin and chitosan

    International Nuclear Information System (INIS)

    Moraes, Mariana A. de; Nogueira, Grinia M.; Weska, Raquel F.; Beppu, Marisa M.

    2009-01-01

    The aim of this study was to prepare and characterize blend membranes of silk fibroin and chitosan. Moreover, a conformation of fibroin to a more stable form induced by the addition of chitosan was verified. Blend membranes of fibroin/chitosan were prepared in different proportions and had their crystallinity, structural conformation and thermal stability characterized. The results of crystallographic analysis (XRD) indicated the tendency to higher structural organization caused by the addition of chitosan. FTIR showed that, mainly in a content of chitosan of only 25%, fibroin is present in a more stable form. Thermal analyzes indicate that fibroin is thermally stable and that when its proportion in the blend increases, the temperature in which the degradation is initiated also does so. (author)

  1. Obtain and characterization of chitosan / propranolol microparticles by spray drying

    International Nuclear Information System (INIS)

    Nascimento, Ednaldo G. do; Silva Junior, Arnobio A. da; Santos, Katia S.C.R. dos

    2015-01-01

    The study investigated the application of chitosan microparticles as carriers into hard gelatin capsule containing propranolol, evaluating the variability of the molecular weight and the chitosan particles by spray drying. The formulations were characterized by average weight, dosing unit dose uniformity and dissolution profile according to the pharmacopoeia. While the microparticles were characterized by Fourier transformed infrared spectroscopy, scanning electron microscopy and X-ray diffraction. The results showed that chitosan microparticles obtained without the drug and then physically mixed with propranolol promoted a modified release 85% of the drug after 5 hours. While, chitosan microparticles sprayed with propranolol released only 55% at 5 hours is presented both as a modified release system. Samples of dried chitosan showed up amorphous and homogeneous and spherical morphology. (author)

  2. Chitosan as flocculant agent for clarification of stevia extract

    Directory of Open Access Journals (Sweden)

    Silvia P. D. de Oliveira

    2012-01-01

    Full Text Available Stevia is used as a sweetener due to its low calorific value and its taste, which is very similar to that of sucrose. After extraction from dried leaves, stevia extract is dark in colour, and therefore needs to be whitened to increase acceptance by consumers. In this study we tested chitosan, a cationic polyelectrolyte, as flocculant agent for the whitening of the Stevia extract. Positive charges of chitosan can interact electrostatically with a counter-ion, sodium tripolyphosphate (TPP, and then chitosan precipitates. A factorial design was used to study the whitening process, in which Glycosides Removal, Colour Removal, Turbidity Removal and Soluble Solids Removal were evaluated. The studied factors were Chitosan Mass and pH of the TPP solution. The results showed that chitosan is a good flocculant agent, being able to flocculate both the glycosides and the pigments that make the extract coloured.

  3. Chitosan magnetic microspheres for technological applications: Preparation and characterization

    International Nuclear Information System (INIS)

    Podzus, P.E.; Daraio, M.E.; Jacobo, S.E.

    2009-01-01

    One of the major applications of chitosan and its many derivatives are based on its ability to bind strongly heavy and toxic metal ions. In this study chitosan magnetic microspheres have been synthesized. Acetic acid (1%w/v) solution was used as solvent for the chitosan polymer solution (2%w/v) where magnetite nanoparticles were suspended in order to obtain a stable ferrofluid. Glutaraldehyde was used as cross-linker. The magnetic characteristic of these materials allows an easy removal after use if is necessary. The morphological characterization of the microspheres shows that they can be produced in the size range 800-1100 μm. The adsorption of Cu(II) onto chitosan-magnetite nanoparticles was studied in batch system. A second-order kinetic model was used to fit the kinetic data, leading to an equilibrium adsorption capacity of 19 mg Cu/g chitosan.

  4. Chitosan as a bioactive polymer: Processing, properties and applications.

    Science.gov (United States)

    Muxika, A; Etxabide, A; Uranga, J; Guerrero, P; de la Caba, K

    2017-12-01

    Chitin is one of the most abundant natural polysaccharides in the world and it is mainly used for the production of chitosan by a deacetylation process. Chitosan is a bioactive polymer with a wide variety of applications due to its functional properties such as antibacterial activity, non-toxicity, ease of modification, and biodegradability. This review summarizes the most common chitosan processing methods and highlights some applications of chitosan in various industrial and biomedical fields. Finally, environmental concerns of chitosan-based films, considering the stages from raw materials extraction up to the end of life after disposal, are also discussed with the aim of finding more eco-friendly alternatives. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Copper nanoparticles synthesis by gamma irradiation in chitosan aqueous system

    International Nuclear Information System (INIS)

    Shahrul Izwan Ahmad; Md Soot Ahmad; Shahidan Radiman

    2009-01-01

    A study on effect of chitosan concentration on the copper nanoparticles synthesis using gamma irradiation as source of reducing agent has been done at total absorbed dose of 50 kGy. The addition of ethanol is vital as scavenger of oxidation radical that eliminate the function of reducing agent produced by radiolysis process of gamma ray in water system. Transmission electron microscopy observations show the formation of copper nanoparticles embedded in chitosan matrix. As the concentration of chitosan increase the solution become darker and nanoparticles produced are densely, in order form with polydisperse size. While at the low concentration of chitosan, the color of solution become more reddish and the particles produced are monodisperse in size with regular shape and more orderly. The phase of pure copper nanoparticles embedded in the chitosan matrix was confirmed by X-ray diffraction. (Author)

  6. Surface grafted chitosan gels. Part II. Gel formation and characterization

    DEFF Research Database (Denmark)

    Liu, Chao; Thormann, Esben; Claesson, Per M.

    2014-01-01

    Responsive biomaterial hydrogels attract significant attention due to their biocompatibility and degradability. In order to make chitosan based gels, we first graft one layer of chitosan to silica, and then build a chitosan/poly(acrylic acid) multilayer using the layer-by-layer approach. After...... cross-linking the chitosan present in the polyelectrolyte multilayer, poly(acrylic acid) is partly removed by exposing the multilayer structure to a concentrated carbonate buffer solution at a high pH, leaving a surface-grafted cross-linked gel. Chemical cross-linking enhances the gel stability against...... detachment and decomposition. The chemical reaction between gluteraldehyde, the cross-linking agent, and chitosan was followed in situ using total internal reflection Raman (TIRR) spectroscopy, which provided a molecular insight into the complex reaction mechanism, as well as the means to quantify the cross...

  7. Phytase-mediated enzymatic mineralization of chitosan-enriched hydrogels

    DEFF Research Database (Denmark)

    Lišková, Jana; Douglas, Timothy E.L.; Wijnants, Robbe

    2018-01-01

    Hydrogels mineralized with calcium phosphate (CaP) are increasingly popular bone regeneration biomaterials. Mineralization can be achieved by phosphatase enzyme incorporation and incubation in calcium glycerophosphate (CaGP). Gellan gum (GG) hydrogels containing the enzyme phytase and chitosan...... oligomer were mineralized in CaGP solution and characterized with human osteoblast-like MG63 cells and adipose tissue-derived stem cells (ADSC). Phytase induced CaP formation. Chitosan concentration determined mineralization extent and hydrogel mechanical reinforcement. Phytase-induced mineralization...... promoted MG63 adhesion and proliferation, especially in the presence of chitosan, and was non-toxic to MG63 cells (with and without chitosan). ADSC adhesion and proliferation were poor without mineralization. Chitosan did not affect ADSC osteogenic differentiation....

  8. Fungal chitosan production from potato processing wastewater and its characterization

    International Nuclear Information System (INIS)

    Khalaf, S.A.; Khalaf, M.A.

    2005-01-01

    Potato processing wastewater (PPW) was collected and analyzed for biological oxygen demand BOD, chemical oxygen demand (COD), total suspended solids (TSS), total nitrogen and starch content. A fungal strain of Aspergillus niger treated with ultraviolet (UV) radiation was evaluated for its ability to produce chitosan from PPW. Active UV-irradiated isolate, coded A. niger UV-2, was able to reduce COD by about 86.15% with over productivity of chitosan of 1630 mgl -1 after 5 days of its cultivation in PPW. Extractable chitosan from this isolate had a degree of deacetylation of 88.4% and a molecular weight l.lxlo 5 Da. Also, the extractable chitosan at concentration 600 mgl -1 exhibited the maximum antibacterial activity compared with crab shell chitosan

  9. The production of fully deacetylated chitosan by compression method

    Directory of Open Access Journals (Sweden)

    Xiaofei He

    2016-03-01

    Full Text Available Chitosan’s activities are significantly affected by degree of deacetylation (DDA, while fully deacetylated chitosan is difficult to produce in a large scale. Therefore, this paper introduces a compression method for preparing 100% deacetylated chitosan with less environmental pollution. The product is characterized by XRD, FT-IR, UV and HPLC. The 100% fully deacetylated chitosan is produced in low-concentration alkali and high-pressure conditions, which only requires 15% alkali solution and 1:10 chitosan powder to NaOH solution ratio under 0.11–0.12 MPa for 120 min. When the alkali concentration varied from 5% to 15%, the chitosan with ultra-high DDA value (up to 95% is produced.

  10. Grape Preservation Using Chitosan Combined with β-Cyclodextrin

    Directory of Open Access Journals (Sweden)

    Yu Youwei

    2013-01-01

    Full Text Available The effect of 1% chitosan combined with 2% β-cyclodextrin to the preservation of fresh grapes under ambient temperature was investigated. The results indicated that the hydrogen bond formed between the hydroxyl group of β-cyclodextrin and the amidogen or hydroxyl group of chitosan and the crystal form of chitosan was also changed when cyclodextrin was doped into chitosan coating. The compound coating could prolong the shelf life of grapes, maintain lower respiration rate and higher activities of superoxide dismutase, peroxidase, and catalase during storage time, and restrain weight loss and malonaldehyde content increase. Coating grapes with chitosan + β-cyclodextrin was a good method in postharvested grape preservation.

  11. Flow Cytometry Detection of Bacterial Cell Entrapment within the Chitosan Hydrogel and Antibacterial Property of Extracted Chitosan

    Directory of Open Access Journals (Sweden)

    Nafise Sadat Majidi

    2016-09-01

    Full Text Available Background:   Chitosan is unbranched polysaccharide composed of D-glucosamine and N-acetyl-D-glucosamine. Chitosan, derived from shrimp shell, has broad antimicrobial properties against Gram-negative, Gram-positive bacteria and fungi. Methods:  Chitosan was extracted from shrimp shell and studied for cell entrapment and anti-bacterial properties. The hydrogel chitosan was used as the beads for cell entrapment and chitosan beads were designed to deliver cells and nutrients. These data confirmed with flow cytometric analyses.                 Results:   Experimental results exhibited that internal diffusion through the chitosan matrix was the main mechanism for whole gelation by TPP (Tri-polyphosphate. The minimum inhibitory concentration (MIC for chitosan against Staphylococcus aureus and Escherichia coli was 16 and 32 μg/ml respectively. Conclusion:  Despite the antimicrobial properties of chitosan, trapped bacteria in the gel network were alive and were chelated indicating that their access to the outside was limited.

  12. Chitosan Dermal Substitute and Chitosan Skin Substitute Contribute to Accelerated Full-Thickness Wound Healing in Irradiated Rats

    Directory of Open Access Journals (Sweden)

    Abu Bakar Mohd Hilmi

    2013-01-01

    Full Text Available Wounds with full-thickness skin loss are commonly managed by skin grafting. In the absence of a graft, reepithelialization is imperfect and leads to increased scar formation. Biomaterials can alter wound healing so that it produces more regenerative tissue and fewer scars. This current study use the new chitosan based biomaterial in full-thickness wound with impaired healing on rat model. Wounds were evaluated after being treated with a chitosan dermal substitute, a chitosan skin substitute, or duoderm CGF. Wounds treated with the chitosan skin substitute showed the most re-epithelialization (33.2 ± 2.8%, longest epithelial tongue (1.62 ± 0.13 mm, and shortest migratory tongue distance (7.11 ± 0.25 mm. The scar size of wounds treated with the chitosan dermal substitute (0.13 ± 0.02 cm and chitosan skin substitute (0.16 ± 0.05 cm were significantly decreased (P<0.05 compared with duoderm (0.45 ± 0.11 cm. Human leukocyte antigen (HLA expression on days 7, 14, and 21 revealed the presence of human hair follicle stem cells and fibroblasts that were incorporated into and surviving in the irradiated wound. We have proven that a chitosan dermal substitute and chitosan skin substitute are suitable for wound healing in full-thickness wounds that are impaired due to radiation.

  13. Anchoring of ulex europaeus agglutinin to chitosan nanoparticles-in-microparticles and their in vitro binding activity to bovine submaxillary gland mucin.

    Science.gov (United States)

    Li, Feng-Qian; Fei, Yi-Bo; Chen, Xu; Qin, Xian-Ju; Liu, Ji-Yong; Zhu, Quan-Gang; Hu, Jin-Hong

    2009-10-01

    Focused on the natural biodegradable material of chitosan (CS), this investigation concerned its spray-dried nanoparticles-in-microparticles (NiMPs) modified with ulex europaeus agglutinin (UEA). Chitosan nanoparticles were obtained by ionotropic gelation process with pentasodium tripolyphosphate as gelatinizer. Then UEA lectin was bound onto the CS nanoparticles activated by glutaraldehyde. The conjugated spherical UEA-CS-NiMPs, prepared by spray drying method, exhibited 12-85% coupling efficiency of UEA depending upon the amount of activator glutaraldehyde. And the UEA-grafted particles showed additional higher binding tendency with bovine submaxillary gland mucin as compared to the plain chitosan microparticles. Furthermore, the activity and intrinsic fucose-specificity of UEA were still maintained after the covalent modification. It is thus evident that the UEA anchored CS-NiMPs might be used as a potential drug delivery system targeted to the specific regions of gastrointestinal tract.

  14. Metal Complexation with Chitosan and its Grafted Copolymer

    International Nuclear Information System (INIS)

    Abo-Hussen, A.A.; Elkholy, S.S.; Elsabee, M.Z.

    2005-01-01

    The adsorption of M (II); Co (II), Ni (If), Cu (II), Zn (II) and Cd (II) from aqueous solutions by chitosan flakes and beads have been studied. The maximum up-take of M (II) ions on chitosan beads was greater than on flakes. Batch adsorption experiments were carried out as a function of ph, agitation period and initial concentration of the metal ions. A ph of 6.0 was found to be optimum for M (II) adsorption on chitosan flakes and beads. The uptake of the ions was determined from the changes in its concentration, as measured by ultraviolet and visible spectroscopy. The metal ions uptake of chitosan grafted with vinyl pyridine (VP) is higher than that of the chitosan. The experimental data of the adsorption equilibrium from M (II)-solutions correlated well with the Langmuir and Freundlich equations. Several spectroscopic methods have been used to study the formation of the polymer/metal cation complex. The cation coordination is accompanied by proton displacement off the polymer or by fixation of a hydroxide ion in aqueous solutions. The largest ionic displacement is observed with Cu (II) and Zn (II) demonstrating the largest affinity of chitosan for these ions. The FT-IR spectral of the complexes show that both the amino and hydroxyl groups of chitosan participated in the chelation process. The ESR spectra of Cu-complex show an absorption at gi 2.06, g// = 2.23, A// x 10-4 (cm-1) = 160 and G = 3.8 indicating the formation of square planar structure. The adsorption of M (II) ions followed the sequence Cu (II) > Zn (II) > Cd (II) > Ni (II) > Co (II), this order seems to be independent on the size and the physical form of chitosan. SEM shows small membranous structure on the surface of chitosan flakes as compared to Cu (Il)- chitosan complex. EDTA was used for the desorption studies

  15. SOLID-STATE FERMENTATIVE PRODUCTION AND BIOACTIVITY OF FUNGAL CHITOSAN

    Directory of Open Access Journals (Sweden)

    Barry Aigbodion Omogbai

    2013-10-01

    Full Text Available Chitosan production was investigated using a laboratory-scale solid substrate fermentation (SSF technique with four species of fungi: Penicillium expansum, Aspergillus niger, Rhizopus oryzae and Fusarium moniliforme.The peak growth for the organisms was after 16 days. Aspergillus niger had the highest growth with a maximal dry cell biomass of 15.8g/kg after 16 days cultivation on corn straw under solid substrate fermentation. This was closely followed by Rhizopus oryzae (14.6g/kg, Penicillium expansum (13.8g/kg and Fusarium moniliforme (10.6g/kg respectively. The fungus Rhizopus oryzae had the highest chitosan production with a maximum of 8.57g/kg in 16 days under solid substrate fermentation (SSF with a medium containing corn straw. Aspergillus niger showed a modest chitosan yield of 6.8g/kg. Penicillium expansum and Fusarium moniliforme had low chitosan yields of 4.31g/kg and 3.1g/kg respectively. The degree of deacetylation of fungal chitosans ranged between 75.3-91.5% with a viscosity of 3.6-7.2 centipoises (Cp.Chitosan extracted from Rhizopus oryzae was found to have antibacterial activity on some bacterial isolates. At a concentration of 50mg/L, Rhizopus oryzae chitosan paralleled crab chitosan in susceptibility testing against some food-borne bacterial pathogens. Escherichia coli, Salmonella typhi, Pseudomonas aeruginosa and Bacillus subtilis showed inhibition rates of 83.2%, 67.9%, 63.8% and 62.4% respectively in response to 50mg/l Rhizopus oryzae chitosan in 24 h. The rate of inhibition (% increased with increase in chitosan concentration.

  16. The antimicrobial action of low-molar-mass chitosan, chitosan derivates and chitooligosaccharides on bifidobacteria

    Czech Academy of Sciences Publication Activity Database

    Šimůnek, Jiří; Koppová, Ingrid; Lukáš, Filip; Tishchenko, Galina; Belzecki, G.

    2010-01-01

    Roč. 55, č. 4 (2010), s. 379-382 ISSN 0015-5632 R&D Projects: GA ČR(CZ) GA525/08/0803 Institutional research plan: CEZ:AV0Z50450515; CEZ:AV0Z40500505 Keywords : chitooligosaccharides * low-molar-mass chitosan Subject RIV: EE - Microbiology, Virology Impact factor: 0.977, year: 2010

  17. Study of sorption properties of nickel on chitosan; Studium sorpcnych vlastnosti niklu na chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Pivarciova, L; Rosskopfova, O; Galambos, M [Univerzita Komenskeho v Bratislave, Prirodovedecka fakulta, Katedra jadrovej chemie, 84215 Bratislava (Slovakia)

    2012-04-25

    Sorption of nickel on the selected sorbent was studied by a batch method. The effect of contact time and pH to reach sorption equilibrium was studied. During sorption of Ni{sup 2+} ions there proceed predominantly ion-exchange reactions on its surface. Time to reach sorption equilibrium of nickel on chitosan was 14 hours. Sorption percentage after 14 hours reached a value of 84 %. Solutions with starting pH value between 3.9 and 8.1 were used for sorption of nickel. A sorption of nickel on chitosan was > 97% in monitored interval of pH after 24 hours of contact . At an initial pH from 3.9 to 6.4 was the final pH 6.6 due to protonisation of amino groups. A pH value was 6.4 after sorption of 7.1. Sorption of nickel is reduced by increasing of concentrations of Ni{sup 2+} ions in the solution. Langmuir isotherm was used for interpretation of nickel sorption on chitosan. A maximum sorption capacity for chitosan was 2,67 {center_dot} 10{sup -3} mol/g{sup -}1. (authors)

  18. Thiolated chitosan nanoparticles as a delivery system for antisense therapy: evaluation against EGFR in T47D breast cancer cells.

    Science.gov (United States)

    Talaei, Fatemeh; Azizi, Ebrahim; Dinarvand, Rassoul; Atyabi, Fatemeh

    2011-01-01

    Thiolated chitosan has high transfection and mucoadhesive properties. We investigated the potential of two recently synthesized polymers: NAC-C (N-acetyl cysteine-chitosan) and NAP-C (N-acetyl penicillamine-chitosan) in anticancer drug delivery targeting epidermal growth factor receptor (EGFR). Doxorubicin (DOX) and antisense oligonucleotide (ASOND)-loaded polymer nanoparticles were prepared in water by a gelation process. Particle characterization, drug loading, and drug release were evaluated. To verify drug delivery efficiency in vitro experiments on a breast cancer cell line (T47D) were performed. EGFR gene and protein expression was analyzed by real time quantitative polymerase chain reaction and Western blotting, respectively. A loading percentage of 63% ± 5% for ASOND and 70% ± 5% for DOX was achieved. Drug release data after 15 hours showed that ASOND and DOX were completely released from chitosan-based particles while a lower and more sustained release of only 22% ± 8% was measured for thiolated particles. In a cytosol simulated release medium/reducing environment, such as found intracellularly, polymer-based nanoparticles dissociated, liberating approximately 50% of both active substances within 7 hours. ASOND-loaded polymer nanoparticles had higher stability and high mucoadhesive properties. The ASOND-loaded thiolated particles significantly suppressed EGFR gene expression in T47D cells compared with ASOND-loaded chitosan particles and downregulated EGFR protein expression in cells. This study could facilitate future investigations into the functionality of NAP-C and NAC-C polymers as an efficient ASOND delivery system in vitro and in vivo.

  19. A new strategy based on SmRho protein loaded chitosan nanoparticles as a candidate oral vaccine against schistosomiasis.

    Directory of Open Access Journals (Sweden)

    Carolina R Oliveira

    Full Text Available 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 nanoparticles containing the antigen SmRho and coated with sodium alginate. METHODS AND FINDINGS: Our results showed an efficient performance of protein loading of nanoparticles before and after coating with alginate. Characterization of the resulting nanoparticles reported a size around 430 nm and a negative zeta potential. In vitro release studies of protein showed great stability of coated nanoparticles in simulated gastric fluid (SGF and simulated intestinal fluid (SIF. Further in vivo studies was performed with different formulations of chitosan nanoparticles and it showed that oral immunization was not able to induce high levels of antibodies, otherwise intramuscular immunization induced high levels of both subtypes IgG1 and IgG2a SmRho specific antibodies. Mice immunized with nanoparticles associated to CpG showed significant modulation of granuloma reaction. Mice from all groups immunized orally with nanoparticles presented significant levels of protection against infection challenge with S. mansoni worms, suggesting an important role of chitosan in inducing a protective immune response. Finally, mice immunized with nanoparticles associated with the antigen SmRho plus CpG had 38% of the granuloma area reduced and also presented 48% of protection against of S. mansoni infection. CONCLUSIONS: Taken together, this results support this new strategy as an efficient delivery system and a potential vaccine against schistosomiasis.

  20. Development and characterization of chitosan-PEG-TAT nanoparticles for the intracellular delivery of siRNA

    Directory of Open Access Journals (Sweden)

    Malhotra M

    2013-05-01

    Full Text Available Meenakshi Malhotra,1 Catherine Tomaro-Duchesneau,1 Shyamali Saha,2 Imen Kahouli,3 Satya Prakash11Biomedical Technology and Cell Therapy Research Laboratory, Department of Biomedical Engineering, Faculty of Medicine, 2Faculty of Dentistry, 3Department of Experimental Medicine, McGill University, Montreal, QC, CanadaAbstract: Recently, cell-penetrating peptides have been proposed to translocate antibodies, proteins, and other molecules in targeted drug delivery. The proposed study presents the synthesis and characterization of a peptide-based chitosan nanoparticle for small interfering RNA (siRNA delivery, in-vitro. Specifically, the synthesis included polyethylene glycol (PEG, a hydrophilic polymer, and trans-activated transcription (TAT peptide, which were chemically conjugated on the chitosan polymer. The conjugation was achieved using N-Hydroxysuccinimide-PEG-maleimide (heterobifunctional PEG as a cross-linker, with the bifunctional PEG facilitating the amidation reaction through its N-Hydroxysuccinimide group and reacting with the amines on chitosan. At the other end of PEG, the maleimide group was chemically conjugated with the cysteine-modified TAT peptide. The degree of substitution on chitosan with PEG and on PEG with TAT was confirmed using colorimetric assays. The resultant polymer was used to form nanoparticles complexing siRNA, which were then characterized for particle size, morphology, cellular uptake, and cytotoxicity. The nanoparticles were tested in-vitro on mouse neuroblastoma cells (Neuro2a. Particle size and surface charge were characterized and an optimal pH condition and PEG molecular weight were determined to form sterically stable nanoparticles. Results indicate 7.5% of the amines in chitosan polymer were conjugated to the PEG and complete conjugation of TAT peptide was observed on the synthesized PEGylated chitosan polymer. Compared with unmodified chitosan nanoparticles, the nanoparticles formed at pH 6 were

  1. Functional gene silencing mediated by chitosan/siRNA nanocomplexes

    Energy Technology Data Exchange (ETDEWEB)

    Ji, A M; Su, D; Che, O; Li, W S; Sun, L; Zhang, Z Y; Xu, F [Department of Pharmaceutical Science, Zhujiang Hospital, Southern Medical University, Guangzhou 510282 (China); Yang, B, E-mail: andrewfxu1998@gmail.co [Department of Chemistry, Indiana University-Bloomington, Bloomington, IN 47405 (United States)

    2009-10-07

    Chitosan/siRNA nanoparticles to knock down FHL2 gene expression were reported in this work. The physicochemical properties such as particle size, surface charge, morphology and complex stability of chitosan nanoparticle-incorporated siRNA were evaluated. Nanoparticles which were formulated with chitosan/siRNA exhibited irregular, lamellar and dendritic structures with a hydrodynamic radius size of about 148 nm and net positive charges with zeta-potential value of 58.5 mV. The knockdown effect of the chitosan/siRNA nanoparticles on gene expression in FHL2 over-expressed human colorectal cancer Lovo cells was investigated. The result showed that FHL2 siRNA formulated within chitosan nanoparticles could knock down about 69.6% FHL2 gene expression, which is very similar to the 68.8% reduced gene expression when siRNA was transfected with liposome Lipofectamine. Western analysis further showed significant FHL-2 protein expression reduced by the chitosan/siRNA nanoparticles. The results also showed that blocking FHL2 expression by siRNA could also inhibit the growth and proliferation of human colorectal cancer Lovo cells. The current results demonstrated that chitosan-based siRNA nanoparticles were a very efficient delivery system for siRNA in vivo as previously reported.

  2. Conjugation of Inulin Improves Anti-Biofilm Activity of Chitosan.

    Science.gov (United States)

    Zhang, Guiqiang; Liu, Jing; Li, Ruilian; Jiao, Siming; Feng, Cui; Wang, Zhuo A; Du, Yuguang

    2018-05-04

    Bacteria biofilm helps bacteria prevent phagocytosis during infection and increase resistance to antibiotics. Staphylococcus aureus is a Gram-positive pathogenic bacterium and is tightly associated with biofilm-related infections, which have led to great threat to human health. Chitosan, the only cationic polysaccharide in nature, has been demonstrated to have antimicrobial and anti-biofilm activities, which, however, require a relative high dosage of chitosan. Moreover, poor water solubility further restricts its applications on anti-infection therapy. Inulins are a group of polysaccharides produced by many types of plants, and are widely used in processed foods. Compared to chitosan, inulin is very soluble in water and possesses a mild antibacterial activity against certain pathogenic bacteria. In order to develop an effective strategy to treat biofilm-related infections, we introduce a method by covalent conjugation of inulin to chitosan. The physicochemical characterization of the inulin⁻chitosan conjugate was assayed, and the anti-biofilm activity was evaluated against S. aureus biofilm. The results indicated that, as compared to chitosan, this novel polysaccharide⁻polysaccharide conjugate significantly enhanced activities against S. aureus either in a biofilm or planktonic state. Of note, the conjugate also showed a broad spectrum anti-biofilm activity on different bacteria strains and low cellular toxicity to mammalian cells. These results suggested that chitosan conjugation of inulin was a viable strategy for treatment against biofilm-related infections. This finding may further spread the application of natural polysaccharides on treatments of infectious disease.

  3. Rheological and structural studies of carboxymethyl derivatives of chitosan

    Science.gov (United States)

    Winstead, Cherese; Katagumpola, Pushpika

    2014-05-01

    The degrees of substitution of chitosan derivatives were varied and the viscoelastic behavior of these biopolymer solutions was studied using rheology. Chitosan is a cationic copolymer of glucosamine and N-acetylglucosamine obtained by alkaline deacetylation of chitin. Due to its inherent non-toxicity, biocompatibility, and biodegradability, chitosan has gained much interest. However, the poor solubility of the biopolymer in water and most common organic solvents limits its applications. Therefore, the focus of this work is the chemical modification of chitosan via carboxymethylation as well as studying the viscoelastic behavior of these polymer solutions. Varying degrees of substitution (DS) of carboxymethyl chitosan derivatives were synthesized by treating chitosan with monochloroacetic acid under alkylated medium varying the reaction time and temperature. The effect of degree of substitution on the rheology of these polymer solutions was studied as a function of concentration. The viscosity of chitosan derivatives sharply increased with increase in degree of substitution. G' and G" dependence on strain and angular frequency were studied and were found to exhibit predominantly viscous behavior. Additional characterization of the derivatized products were further studied using Fourier transform infrared (FT-IR), 1H Nuclear Magnetic Resonance (1H NMR) spectroscopy, X-ray diffraction (XRD), and thermal gravimetric analysis as well as differential scanning calorimetry (DSC). Degree of substitution (DS) was calculated by titrimetric method.

  4. Chitosan-coupled solid lipid nanoparticles: Tuning nanostructure and mucoadhesion.

    Science.gov (United States)

    Sandri, Giuseppina; Motta, Simona; Bonferoni, Maria Cristina; Brocca, Paola; Rossi, Silvia; Ferrari, Franca; Rondelli, Valeria; Cantù, Laura; Caramella, Carla; Del Favero, Elena

    2017-01-01

    Solid Lipid Nanoparticles (SLNs) composed of biodegradable physiological lipids have been widely proposed as efficient drug delivery systems, also for ophthalmic administration. Recently, chitosan-associated-SLNs have been developed to further improve the residence time of these colloidal systems in the precorneal area by means of mucoadhesive interaction. In the present study, a one-step preparation protocol was used aiming both at scale-up ease and at stronger coupling between chitosan and SLNs. The resulting particles were chitosan associated-SLNs (CS-SLNs). These nanoparticles were characterized, as compared to both the chitosan-free and the usual chitosan-coated ones, by applying a multi-technique approach: light, neutron and X-ray scattering, Zeta-potential, AFM, calorimetry. It was assessed that, while keeping the features of nano-size and surface-charge required for an efficient vector, these new nanoparticles display a strong and intimate interaction between chitosan and SLNs, far more settled than the usual simple coverage. Moreover, this one-step preparation method allows to obtain a strong and intimate interaction between chitosan and SLNs, firmer than the usual simple coating. This confers to the CS-SLNs an improved mucoadhesion, opening the way for a high-performing ophthalmic formulation. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Toxicity tests, antioxidant activity, and antimicrobial activity of chitosan

    Science.gov (United States)

    Kurniasih, M.; Purwati; Dewi, R. S.

    2018-04-01

    Chitosan is a naturally occurring cationic biopolymer, obtained by alkaline deacetylation of chitin. This research aims to investigate the toxicity, antioxidant activity and antibacterial activity of chitosan from shrimp chitin. In this study, chitin extracted from shrimp waste material. Chitin is then deacetylation with 60% NaOH so that chitosan produced. Degrees of deacetylation, molecular weight, toxicity test, antioxidant activity and antimicrobial activity of chitosan then evaluated. Toxicity test using Brine Shrimp Lethality Test. The antioxidant analysis was performed using DPPH method (2, 2-diphenyl-1-picrylhydrazyl) and FTC method (ferric thiocyanate) in which the radical formed will reduce Ferro to Ferri resulting in a complex with thiocyanate. To determine the antibacterial activity of Staphylococcus aureus, antifungal in Candida albicans and Aspergillus niger by measuring antimicrobial effects and minimum inhibitory concentrations (MIC). Based on the result of research, the value of degrees of deacetylation, molecular weight, and LC50 values of chitosan synthesis was 94,32, 1052.93 g/mol and 1364.41 ppm, respectively. In general, the antioxidative activities increased as the concentration of chitosan increased. MIC value of chitosan against S. aureus, C. albicans, and A. niger was 10 ppm, 15.6 ppm, and 5 ppm, respectively.

  6. Rheological and structural studies of carboxymethyl derivatives of chitosan

    International Nuclear Information System (INIS)

    Winstead, Cherese; Katagumpola, Pushpika

    2014-01-01

    The degrees of substitution of chitosan derivatives were varied and the viscoelastic behavior of these biopolymer solutions was studied using rheology. Chitosan is a cationic copolymer of glucosamine and N-acetylglucosamine obtained by alkaline deacetylation of chitin. Due to its inherent non-toxicity, biocompatibility, and biodegradability, chitosan has gained much interest. However, the poor solubility of the biopolymer in water and most common organic solvents limits its applications. Therefore, the focus of this work is the chemical modification of chitosan via carboxymethylation as well as studying the viscoelastic behavior of these polymer solutions. Varying degrees of substitution (DS) of carboxymethyl chitosan derivatives were synthesized by treating chitosan with monochloroacetic acid under alkylated medium varying the reaction time and temperature. The effect of degree of substitution on the rheology of these polymer solutions was studied as a function of concentration. The viscosity of chitosan derivatives sharply increased with increase in degree of substitution. G' and G' dependence on strain and angular frequency were studied and were found to exhibit predominantly viscous behavior. Additional characterization of the derivatized products were further studied using Fourier transform infrared (FT-IR), 1 H Nuclear Magnetic Resonance ( 1 H NMR) spectroscopy, X-ray diffraction (XRD), and thermal gravimetric analysis as well as differential scanning calorimetry (DSC). Degree of substitution (DS) was calculated by titrimetric method

  7. Emerging Chitosan-Based Films for Food Packaging Applications.

    Science.gov (United States)

    Wang, Hongxia; Qian, Jun; Ding, Fuyuan

    2018-01-17

    Recent years have witnessed great developments in biobased polymer packaging films for the serious environmental problems caused by the petroleum-based nonbiodegradable packaging materials. Chitosan is one of the most abundant biopolymers after cellulose. Chitosan-based materials have been widely applied in various fields for their biological and physical properties of biocompatibility, biodegradability, antimicrobial ability, and easy film forming ability. Different chitosan-based films have been fabricated and applied in the field of food packaging. Most of the review papers related to chitosan-based films are focusing on antibacterial food packaging films. Along with the advances in the nanotechnology and polymer science, numerous strategies, for instance direct casting, coating, dipping, layer-by-layer assembly, and extrusion, have been employed to prepare chitosan-based films with multiple functionalities. The emerging food packaging applications of chitosan-based films as antibacterial films, barrier films, and sensing films have achieved great developments. This article comprehensively reviews recent advances in the preparation and application of engineered chitosan-based films in food packaging fields.

  8. Can fungi compete with marine sources for chitosan production?

    Science.gov (United States)

    Ghormade, V; Pathan, E K; Deshpande, M V

    2017-11-01

    Chitosan, a β-1,4-linked glucosamine polymer is formed by deacetylation of chitin. It has a wide range of applications from agriculture to human health care products. Chitosan is commercially produced from shellfish, shrimp waste, crab and lobster processing using strong alkalis at high temperatures for long time periods. The production of chitin and chitosan from fungal sources has gained increased attention in recent years due to potential advantages in terms of homogenous polymer length, high degree of deacetylation and solubility over the current marine source. Zygomycetous fungi such as Absidia coerulea, Benjaminiella poitrasii, Cunninghamella elegans, Gongrenella butleri, Mucor rouxii, Mucor racemosus and Rhizopus oryzae have been studied extensively. Isolation of chitosan are reported from few edible basidiomycetous fungi like Agaricus bisporus, Lentinula edodes and Pleurotus sajor-caju. Other organisms from mycotech industries explored for chitosan production are Aspergillus niger, Penicillium chrysogenum, Saccharomyces cerevisiae and other wine yeasts. Number of aspects such as value addition to the existing applications of fungi, utilization of waste from agriculture sector, and issues and challenges for the production of fungal chitosan to compete with existing sources, metabolic engineering and novel applications have been discussed to adjudge the potential of fungal sources for commercial chitosan production. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Functional gene silencing mediated by chitosan/siRNA nanocomplexes

    International Nuclear Information System (INIS)

    Ji, A M; Su, D; Che, O; Li, W S; Sun, L; Zhang, Z Y; Xu, F; Yang, B

    2009-01-01

    Chitosan/siRNA nanoparticles to knock down FHL2 gene expression were reported in this work. The physicochemical properties such as particle size, surface charge, morphology and complex stability of chitosan nanoparticle-incorporated siRNA were evaluated. Nanoparticles which were formulated with chitosan/siRNA exhibited irregular, lamellar and dendritic structures with a hydrodynamic radius size of about 148 nm and net positive charges with zeta-potential value of 58.5 mV. The knockdown effect of the chitosan/siRNA nanoparticles on gene expression in FHL2 over-expressed human colorectal cancer Lovo cells was investigated. The result showed that FHL2 siRNA formulated within chitosan nanoparticles could knock down about 69.6% FHL2 gene expression, which is very similar to the 68.8% reduced gene expression when siRNA was transfected with liposome Lipofectamine. Western analysis further showed significant FHL-2 protein expression reduced by the chitosan/siRNA nanoparticles. The results also showed that blocking FHL2 expression by siRNA could also inhibit the growth and proliferation of human colorectal cancer Lovo cells. The current results demonstrated that chitosan-based siRNA nanoparticles were a very efficient delivery system for siRNA in vivo as previously reported.

  10. Experimental evaluation of new chitin-chitosan graft for duraplasty.

    Science.gov (United States)

    Pogorielov, M; Kravtsova, A; Reilly, G C; Deineka, V; Tetteh, G; Kalinkevich, O; Pogorielova, O; Moskalenko, R; Tkach, G

    2017-02-01

    Natural materials such as collagen and alginate have promising applications as dural graft substitutes. These materials are able to restore the dural defect and create optimal conditions for the development of connective tissue at the site of injury. A promising material for biomedical applications is chitosan-a linear polysaccharide obtained by the deacetylation of chitin. It has been found to be nontoxic, biodegradable, biofunctional and biocompatible in addition to having antimicrobial characteristics. In this study we designed new chitin-chitosan substitutes for dura mater closure and evaluated their effectiveness and safety. Chitosan films were produced from 3 % of chitosan (molar mass-200, 500 or 700 kDa, deacetylation rate 80-90%) with addition of 20% of chitin. Antimicrobial effictively and cell viability were analysed for the different molar masses of chitosan. The film containing chitosan of molar mass 200 kDa, had the best antimicrobial and biological activity and was successfully used for experimental duraplasty in an in vivo model. In conclusion the chitin-chitosan membrane designed here met the requirements for a dura matter graft exhibiting the ability to support cell growth, inhibit microbial growth and biodegradade at an appropriate rate. Therefore this is a promising material for clinical duroplasty.

  11. Evaluation of Hemagglutination Activity of Chitosan Nanoparticles Using Human Erythrocytes

    Directory of Open Access Journals (Sweden)

    Jefferson Muniz de Lima

    2015-01-01

    Full Text Available Chitosan is a polysaccharide composed of randomly distributed chains of β-(1-4 D-glucosamine and N-acetyl-D-glucosamine. This compound is obtained by partial or total deacetylation of chitin in acidic solution. The chitosan-based hemostatic agents have been gaining much attention in the management of bleeding. The aim of this study was to evaluate in vitro hemagglutination activity of chitosan nanoparticles using human erythrocytes. The preparation of nanoparticles was achieved by ionotropic gelification technique followed by neutralization with NaOH 1 mol/L−1. The hemagglutination activity was performed on a solution of 2% erythrocytes (pH 7.4 on PBS collected from five healthy volunteers. The hemolysis determination was made by spectrophotometric analysis. Chitosan nanoparticle solutions without NaOH addition changed the reddish colour of the wells into brown, suggesting an oxidative reaction of hemoglobin and possible cell lysis. All neutralized solutions of chitosan nanoparticles presented positive haemagglutination, without any change in reaction color. Chitosan nanoparticles presented hemolytic activity ranging from 186.20 to 223.12%, while neutralized solutions ranged from 2.56 to 72.54%, comparing to distilled water. Results highlight the need for development of new routes of synthesis of chitosan nanoparticles within human physiologic pH.

  12. Chemical coupling of thiolated chitosan to preformed liposomes improves mucoadhesive properties

    Directory of Open Access Journals (Sweden)

    Gradauer K

    2012-05-01

    Full Text Available Kerstin Gradauer,1 Caroline Vonach,1 Gerd Leitinger,2,3 Dagmar Kolb,2,3 Eleonore Fröhlich,3 Eva Roblegg,4 Andreas Bernkop-Schnürch,5 Ruth Prassl1,61Institute of Biophysics and Nanosystems Research, Austrian Academy of Sciences, Graz, Austria; 2Institute of Cell Biology, Histology, and Embryology, Medical University of Graz, Graz, Austria; 3Center for Medical Research, Medical University of Graz, Graz, Austria; 4Institute of Pharmaceutical Sciences/Pharmaceutical Technology, Karl-Franzens University, Graz, Austria; 5Department of Pharmaceutical Technology, Institute of Pharmacy, University of Innsbruck, Innsbruck, Austria; 6Ludwig Boltzmann Institute for Lung Vascular Research, Graz, AustriaAim: To develop mucoadhesive liposomes by anchoring the polymer chitosan-thioglycolic acid (chitosan-TGA to the liposomal surface to target intestinal mucosal membranes.Methods: Liposomes consisting of phosphatidylcholine (POPC and a maleimide-functionalized lipid were incubated with chitosan-TGA, leading to the formation of a thioether bond between free SH-groups of the polymer and maleimide groups of the liposome. Uncoated and newly generated thiomer-coated liposomes were characterized according to their size, zeta potential, and morphology using photon correlation spectroscopy and transmission electron microscopy. The release behavior of calcitonin and the fluorophore/quencher-couple ANTS/DPX (8-aminonaphthalene-1,3,6-trisulfonic acid/p-xylene-bis- pyridinium bromide from coated and uncoated liposomes, was investigated over 24 hours in simulated gastric and intestinal fluids. To test the mucoadhesive properties of thiomer-coated and uncoated liposomes in-vitro, we used freshly excised porcine small intestine.Results: Liposomes showed a concentration-dependent increase in size – from approximately 167 nm for uncoated liposomes to 439 nm for the highest thiomer concentration used in this study. Likewise, their zeta potentials gradually increased from

  13. Chitosan-nanosilica hybrid materials: Preparation and properties

    International Nuclear Information System (INIS)

    Podust, T.V.; Kulik, T.V.; Palyanytsya, B.B.; Gun’ko, V.M.; Tóth, A.; Mikhalovska, L.; Menyhárd, A.; László, K.

    2014-01-01

    Highlights: • Hybrid chitosan-nanosilica materials were synthesized using an adsorption modification method. • The chitosan adsorption capacity is higher on the silica/titania and silica/alumina than on the fumed silica. • Nanosilicas undergo structural and textural alterations due to modification by chitosan. • The more severe chitosan thermodestruction occurs on the silica/titania and silica/alumina surfaces than on the plain silica surface. - Abstract: The research focuses on the synthesis of novel organic–inorganic hybrid materials based on polysaccharide chitosan and nanosilicas (SiO 2 , TiO 2 /SiO 2 and Al 2 O 3 /SiO 2 ). The chitosan modified nanooxides were obtained by the equilibrium adsorption method. The chitosan adsorption capacities of silica/titania and silica/alumina are higher than of the plain silica due to the additional active sites present on the surfaces of the mixed oxides. The hybrid materials were characterized by low-temperature nitrogen adsorption/desorption, photon correlation spectroscopy (PCS), scanning electron microscopy (SEM), thermogravimetry (TG/DTG) and temperature-programmed desorption with mass spectrometry control (TPD MS) methods. The chitosan treatment only modestly influences the surface area S BET of the nanooxides but the rearrangement of the secondary and tertiary structures (aggregates and agglomerates) results in an enhancement of the mesoporosity and affects the size of the aggregates. The more severe thermodestruction of the polysaccharide desorbing from the modified mixed silicas indicates a stronger interaction between the chitosan and the mixed oxides compared to the silanol groups of the plain silica surface

  14. Chitosan-nanosilica hybrid materials: Preparation and properties

    Energy Technology Data Exchange (ETDEWEB)

    Podust, T.V., E-mail: tania_list@yahoo.com [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, Kyiv 03164 (Ukraine); Kulik, T.V., E-mail: tanyakulyk@i.ua [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, Kyiv 03164 (Ukraine); Palyanytsya, B.B.; Gun’ko, V.M. [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, Kyiv 03164 (Ukraine); Tóth, A. [Department of Physical Chemistry and Material Science, Budapest University of Technology and Economics, H-1521 Budapest (Hungary); Mikhalovska, L. [School of Pharmacy and Biomolecular Sciences, University of Brighton, Lewes Road, Brighton BN2 4GJ (United Kingdom); Menyhárd, A. [Department of Physical Chemistry and Material Science, Budapest University of Technology and Economics, H-1521 Budapest (Hungary); Institute of Materials Science and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences (Hungary); László, K. [Department of Physical Chemistry and Material Science, Budapest University of Technology and Economics, H-1521 Budapest (Hungary)

    2014-11-30

    Highlights: • Hybrid chitosan-nanosilica materials were synthesized using an adsorption modification method. • The chitosan adsorption capacity is higher on the silica/titania and silica/alumina than on the fumed silica. • Nanosilicas undergo structural and textural alterations due to modification by chitosan. • The more severe chitosan thermodestruction occurs on the silica/titania and silica/alumina surfaces than on the plain silica surface. - Abstract: The research focuses on the synthesis of novel organic–inorganic hybrid materials based on polysaccharide chitosan and nanosilicas (SiO{sub 2}, TiO{sub 2}/SiO{sub 2} and Al{sub 2}O{sub 3}/SiO{sub 2}). The chitosan modified nanooxides were obtained by the equilibrium adsorption method. The chitosan adsorption capacities of silica/titania and silica/alumina are higher than of the plain silica due to the additional active sites present on the surfaces of the mixed oxides. The hybrid materials were characterized by low-temperature nitrogen adsorption/desorption, photon correlation spectroscopy (PCS), scanning electron microscopy (SEM), thermogravimetry (TG/DTG) and temperature-programmed desorption with mass spectrometry control (TPD MS) methods. The chitosan treatment only modestly influences the surface area S{sub BET} of the nanooxides but the rearrangement of the secondary and tertiary structures (aggregates and agglomerates) results in an enhancement of the mesoporosity and affects the size of the aggregates. The more severe thermodestruction of the polysaccharide desorbing from the modified mixed silicas indicates a stronger interaction between the chitosan and the mixed oxides compared to the silanol groups of the plain silica surface.

  15. Chitosan composite hydrogels reinforced with natural clay nanotubes.

    Science.gov (United States)

    Huang, Biao; Liu, Mingxian; Zhou, Changren

    2017-11-01

    Here, chitosan composites hydrogels were prepared by addition of halloysite nanotubes (HNTs) in the chitosan KOH/LiOH/urea solution. The raw chitosan and chitosan/HNTs composite hydrogels were obtained by heat treatment at 60°C for 8h and then regeneration in ethanol solution. The viscosity of the composite solution is increased with HNTs content. The Fourier transform infrared spectroscopy (FT-IR) shows that the hydrogen bonds interactions exist between the HNTs and the chitosan. X-ray diffraction (XRD) results show that the crystal structure of HNT is not changed in the composite hydrogels. The compressive property test and storage modulus determination show that the mechanical properties and anti-deformation ability of the composite hydrogel significantly increase owing to the reinforcing effect of HNTs. The composites hydrogel with 66.7% HNTs can undergo 7 times compression cycles without breaking with compressive strength of 0.71MPa at 70% deformation, while pure chitosan hydrogel is broken after bearing 5 compression cycles with compressive strength of 0.14MPa and a maximum deformation of 59%. A porous structure with pore size of 100-500μm is found in the composite hydrogels by scanning electron microscopy (SEM), and the pore size and the swelling ratio in NaCl solution decrease by the addition of HNTs and the immersing of ethanol. Chitosan/HNTs composite hydrogels show low cytotoxicity towards MC3T3-E1 cells. Also, the composite hydrogels show a maximum drug entrapment efficiency of 45.7% for doxorubicin (DOX) which is much higher than that of pure chitosan hydrogel (27.5%). All the results illustrate that the chitosan/HNTs composite hydrogels show promising applications as biomaterials. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Magnetic chitosan for removal of uranium (VI)

    International Nuclear Information System (INIS)

    Stopa, Luiz Claudio Barbosa

    2007-01-01

    The chitosan, an aminopolysaccharide formed for repeated units of D-glucosamine, is a deacetylation product of chitin. It presents favorable ionic properties acting as chelant, being considered a removing ionic of contaminants from water effluents. It has ample bioactivity, that is, is biocompatible, biodegradable, bioadhesive and biosorbent. The chitosan interacts for crosslinked by means of its active groups with other substances, can still coat superparamagnetic materials as magnetite nanoparticles producing one conjugated polymer-magnetite. Superparamagnetic materials are susceptible for the magnetic field, thus these particles can be attracted and grouped by a magnetic field and as they do not hold back the magnetization, they can be disagrouped and reused in processes for removal of contaminants from industrial effluents and waste water. The present work consisted of preparing coated magnetic magnetite particles with chitosan (PMQ). The PMQ powder has showed a magnetic response of intense attraction in the presence of a magnetic field without however becoming magnetic, a typical behavior of superparamagnetic material. It was characterized by Fourier transform infrared spectrometry and measurements of magnetization. Its performance of Uranium (VI) adsorption as uranyl species, U0 2 2+ , was evaluated with regard to the influence of adsorbent dose, speed of agitation, pH, the contact time and had studied the isotherms of adsorption as well as the behavior of desorption using ions of carbonate and oxalate. The optimal pH to the best removal occurred in pH 5 and that the increase of the dose increases the removal, becoming constant above of 20 g.L -1 . In the kinetic study the equilibrium was achieved after 20 minutes. The results of equilibrium isotherm agreed well with the Langmuir model, being the maximum adsorption capacity equal 41.7 mg.g -1 . In the desorption studies were verified 94% of U0 2 2+ recovered with carbonate ion and 49.9% with oxalate ion

  17. Recent Advances of Chitosan Applications in Plants

    Directory of Open Access Journals (Sweden)

    Massimo Malerba

    2018-01-01

    Full Text Available In recent years, the search for biological methods to avoid the application of chemical products in agriculture has led to investigating the use of biopolymers-based materials. Among the tested biomaterials, the best results were obtained from those based on the biopolymer chitosan (CHT. CHT, available in large quantities from the deacetylation of chitin, has multiple advantages: it is safe, inexpensive and can be easily associated with other compounds to achieve better performance. In this review, we have summarized the latest researches of the application of CHT on plant productivity, plant protection against the attack of pathogens and extension of the commercial life of detached fruits.

  18. Development of chitosan derivatives with anhydride maleic

    International Nuclear Information System (INIS)

    Silva, Solranny C.C.C.; Braz, Elton Marks de A.; Brito, Carla Adriana R. de S.; Silva, Durcilene A. da; Junior, Luiz de S.S.; Silva Filho, Edson C. da

    2015-01-01

    Chitosan was chemically modified with maleic anhydride in ratios of 1/2, 1/5 and 1/10 in the absence of solvents. The obtained derivatives were characterized by elemental analysis, FTIR, thermal analysis (TGA / DTG) and XRD where it was possible to prove the chemical modification. Elemental analysis showed an increase of the relation C / N with the increasing of the proportion of anhydrides. The FTIR showed the incorporation of the anhydride in the biopolymer structure. The thermal stability of the derivatives was lower in comparison to the polysaccharide and by XRD the modified materials were less crystalline. (author)

  19. Preparation and protection of silver nanoparticles with chitosan derivative

    International Nuclear Information System (INIS)

    Nguyen Thi Kim Cuc; Cao Van Du; Nguyen Cuu Khoa; Tran Ngoc Quyen

    2013-01-01

    In this paper, nano silver solution is prepared and stabilized by chitosan dihydroxyphenyl acetamide (CDHPA). Chitosan is a natural carbohydrate polymer deriving from chitin that has biodegradable, biocompatible, antibacterial and antifungal properties, so when conjugation of the polymer and silver nanoparticles could be expected to increase bactericidal features of the obtained product. The chemical and physical methods were used to characterize the chitosan derivative such as transmission spectrum (UV-Vis), IR spectrum, nuclear magnetic resonance (1H-NMR). Morphology of the obtained nano silver particles were observed by transmission electron microscopy (TEM). (author)

  20. Practical γ-Ray Level for Low Molecular Weight Chitosan

    International Nuclear Information System (INIS)

    Yoksan, Rangrong; Chirachanchai, Suwabun; Biramontri, Siriratana

    2003-06-01

    The present work proposes a practical level of γ-Ray to lower the molecular weigh of chitosan irradiated in solid state and water. The molecular weight reduction is up to 80% at γ-ray amount of 50 kGy. The same level of reduction can be achieved by only 20 kGy in the presence of initiator (K 2 S 2 O 8 or H 2 O 2 ). The structure is significantly changed in the case of chitosan-acetic acid solution or chitosan dispersed in water with 2% aq. K 2 S 2 O 8 solution

  1. Incorporation of osteogenic and angiogenic small interfering RNAs into chitosan sponge for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Jia S

    2014-11-01

    Full Text Available Sen Jia,1,* Xinjie Yang,1,* Wen Song,2,* Lei Wang,1 Kaixiu Fang,3 Zhiqiang Hu,1,4 Zihui Yang,1 Chun Shan,1 Delin Lei,1 Bin Lu1 1Department of Oral and Maxillofacial Surgery, 2Department of Prosthetic Dentistry, 3Department of Implant Dentistry, School of Stomatology, State Key Laboratory of Military Stomatology, Fourth Military Medical University, Xi’an People’s Republic of China; 4Department of Otorhinolaryngology, No 113 Hospital of People’s Liberation Army, Ningbo, People’s Republic of China *These authors contributed to this paper equally and are considered to be joint first authors Abstract: Engineered bone substitutes are being extensively explored in response to growing demand. However, the angiogenesis that occurs during bone formation is often overlooked in scaffold design. In this novel study, we incorporated two small interfering RNAs (siRNAs, ie, small interfering RNA targets casein kinase 2 interaction protein 1 (siCkip-1 and small interfering RNA targets soluble VEGF receptor 1 (siFlt-1, which can promote osteogenesis and angiogenesis, into a chitosan sponge. This scaffold could maintain siRNAs for over 2 weeks in neutral phosphate-buffered saline and degraded rapidly in the presence of lysozyme. The chitosan sponge with siCkip-1 and siFlt-1 in vitro bioactivity was investigated using mesenchymal stem cells. Target genes were significantly suppressed, and osteocalcin, alkaline phosphatase, and vascular endothelial growth factor were significantly upregulated. Alizarin Red staining revealed that mineralization of the extracellular matrix was markedly enhanced by dual transfection. Further analysis by immunofluorescence confirmed that the siRNA-modified scaffold simultaneously improved the expression of osteocalcin and von Willebrand factor. In vivo testing in a skull critical-size defect model showed marked bone regeneration in rats treated with siCkip-1 and siFlt-1. In conclusion, chitosan sponge containing osteogenic and

  2. Formulation and development of colon-targeted mucopenetrating ...

    African Journals Online (AJOL)

    Purpose: To formulation and develop colon-targeted mucopenetrating metronidazole nanoparticles. Methods: Metronidazole-loaded chitosan nanoparticles with a pH-sensitive polymer, hydroxyl propyl methyl cellulose phthalate (HPMCP), were prepared by ionic gelation technique and then coated with Eudragit S100 by ...

  3. Radiation degradation of alginate and chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Nagasawa, Naotsugu; Mitomo, Hiroshi [Department of Biological and Chemical Engineering, Faculty of Engineering, Gunma University, Kiryu, Gunma (Japan); Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2000-03-01

    Alginate and chitosan were irradiated in solid or aqueous solution condition with Co{sup 60} gamma rays in the dose range of 20 to 500 kGy. Degradation was observed both in solid and solution conditions. The degradation in solution was remarkably greater than that in solid. For example, the molecular weight of alginate in 4%(w/v) solution decreased from 2 x 10{sup 5} for 0 kGy to 6 x 10{sup 3} for 50 kGy irradiation while the equivalent degradation by solid irradiation required 500 kGy. The activated species from irradiated water must be responsible for the degradation in solution. The degradation was also accompanied with the color change of alginate: the color became deep brown for highly degraded alginate. UV spectra showed a distinct absorption peak at 265 nm for colored alginates, increasing with dose. The fact that discoloration of colored alginate was caused on exposure to ozone suggests a formation of double bond in pyranose-ring by scission of glycosidic bond. Degradation behavior of chitosan in irradiation was almost the same as that of alginate. (author)

  4. Chitosan adhesive for laser tissue repair

    Science.gov (United States)

    Lauto, A.; Stoodley, M.; Avolio, A.; Foster, L. J. R.

    2006-02-01

    Background. Laser tissue repair usually relies on haemoderivate solders, based on serum albumin. These solders have intrinsic limitations that impair their widespread use, such as limited repair strength, high solubility, brittleness and viral transmission. Furthermore, the solder activation temperature (65-70 °C) can induce significant damage to tissue. In this study, a new laser-activated biomaterial for tissue repair was developed and tested in vitro and in vivo to overcome some of the shortcomings of traditional solders. Materials and Methods. Flexible and insoluble strips of chitosan adhesive (surface area ~34 mm2, thickness ~20 μm) were developed and bonded on sheep intestine with a laser fluence and irradiance of 52 +/- 2 J/cm2 and ~15 W/cm2 respectively. The temperature between tissue and adhesive was measured using small thermocouples. The strength of repaired tissue was tested by a calibrated tensiometer. The adhesive was also bonded in vivo to the sciatic nerve of rats to assess the thermal damage induced by the laser (fluence = 65 +/- 11 J/cm2, irradiance = 15 W/cm2) four days post-operatively. Results. Chitosan adhesives successfully repaired intestine tissue, achieving a repair strength of 0.50 +/- 0.15 N (shear stress = 14.7 +/- 4.7 KPa, n=30) at a temperature of 60-65 °C. The laser caused demyelination of axons at the operated site; nevertheless, the myelinated axons retained their normal morphology proximally and distally.

  5. development and evaluation of lyophilized thiolated-chitosan wafers

    African Journals Online (AJOL)

    User

    THIOLATED-CHITOSAN WAFERS FOR BUCCAL DELIVERY. OF PROTEIN ... of the thiolated polymer incorporating per polymer weight, 10 % each of glycerol as plasticizer, D-mannitol as ..... delivery systems: in vitro stability, in vivo fate, and ...

  6. Dietary effects of chitosan and buckwheat (Fagopyrum esculentum ...

    African Journals Online (AJOL)

    Sohel

    2015-11-04

    Nov 4, 2015 ... esculentum) alone or in combination with chitosan, in broiler diets, on the growth, feed intake and ..... Body weight gain was calculated by subtracting the body weight at the beginning of the week from the ..... Asian Austral.

  7. Development of Alginate/Chitosan Microparticles for Dust Mite ...

    African Journals Online (AJOL)

    Erah

    surface of chitosan microparticles [4]. .... The reverse-phase high performance liquid .... The surface charge of alginate ... negative charge was as a result of the alginate on the microparticle surface. ... electrostatic interaction of the positively-.

  8. Development and Optimization of Insulin-Chitosan Nanoparticles

    African Journals Online (AJOL)

    to optimize formulation. Properties such as particle shape, size, zeta potential and release behavior ... the positively charged chitosan nanoparticles had strong electrostatic ... dropping 3 ml of TPP reserve liquid quickly into the system at 40 ºC ...

  9. Curcumin loaded in bovine serum albumin–chitosan derived ...

    Indian Academy of Sciences (India)

    study proved that BSA–chitosan based nanoparticles can be used as an efficient vehicle for effective curcumin ... tions in treating cerebral ischaemia by delivering Tanshinone. ∗ ... curcumin is its poor water solubility, which in turn reduces.

  10. Obtention and characterization of chitin and chitosan from M. rosenbergii

    International Nuclear Information System (INIS)

    Battisti, Marcos V.; Campana Filho, Sergio P.

    2001-01-01

    Chitin was extracted from previously ground shells of Macrobrachium rosenbergii by applying acid and alkaline treatments, aiming at its demineralization and deprotenization, respectively. Its characteristics and properties were compared with those exhibited by commercial samples of chitin. Commercial chitosan and samples produced by the deacetylation of chitin obtained from M. rosenbergii shells were also compared. Average degrees of acetylation and intrinsic viscosities of the chitosan were determined by 1 H NMR spectroscopy and by capillary viscosimetry, respectively. The results show that the chitin extracted from Macrobrachium rosenbergii has a lower content of inorganic materials as compared to commercial samples but the chitosan obtained from the former chitin sample is very similar to commercial chitosan. (author)

  11. Effectiveness of Gamma Irradiated Chitosan for Fresh Meat Preservation

    International Nuclear Information System (INIS)

    Zahran, D.A.

    2015-01-01

    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.

  12. Chitosan as an effective inhibitor of multidrug resistant Acinetobacter baumannii.

    Science.gov (United States)

    Costa, E M; Silva, S; Vicente, S; Veiga, M; Tavaria, F; Pintado, M M

    2017-12-15

    Over the last two decades worldwide levels of antibiotic resistance have risen leading to the appearance of multidrug resistant microorganisms. Acinetobacter baumannii is a known skin pathogen which has emerged as a major cause of nosocomial outbreaks due to its capacity to colonize indwelling medical devices and natural antibiotic resistance. With chitosan being an effective antimicrobial agent against antibiotic resistant microorganisms, the aim of this work was to access its potential as an alternative to traditional antimicrobials in the management of A. baumannii growth. What the results showed was that both chitosan MW's tested were active upon A. baumannii's planktonic and sessile growth. For planktonic growth MICs and MBCs were obtained at relatively low concentrations (0.5-2mg/mL) while for sessile growth chitosan proved to be an effective inhibitor of A. baumannii's adhesion and biofilm formation. Considering these results chitosan shows a high potential for control of A. baumannii infections. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Drug delivery glucantime in PVP/chitosan membranes

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Maria J.A.; Lugao, Ademar B.; Parra, Duclerc F., E-mail: mariajhho@yahoo.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Amato, Valdir S. [Universidade de Sao Paulo (DMIP/FM/USP), Sao Paulo, SP (Brazil). Faculdade de Medicina. Departamento de Molestias Infecciosas e Parasitarias

    2015-07-01

    The current study of polymer science considers the area of biomedical application very important to establish developments in new polymeric materials. Examples of that are hydrogels for controlled release of drugs. In this work, hydrogels of poly (N-2-vinil-pyrrolidone) (PVP) containing chitosan and clay nanoparticles were obtained and characterized to investigate chitosan influence on Glucantime drug delivery. The matrixes were crosslinked by gamma irradiation process with doses of 25 kGy. Hydrogels morphologies were observed by X Ray diffraction (DRX). Atomic Force Microscopy (AFM) and swelling kinetic at 22 °C to study the capacity of water retention and, finally, drug delivery tests were performed 'in vitro'. The system showed higher gel fraction for the matrix with 1.0% of clay and 0.5% of chitosan. In this case, besides the interactions of clay ions with PVP, there are interactions of chitosan amine group with PVP amide group. (author)

  14. Synthesis of chitosan derivative with diethyldithiocarbamate and its antifungal activity.

    Science.gov (United States)

    Qin, Yukun; Xing, Ronge; Liu, Song; Li, Kecheng; Hu, Linfeng; Yu, Huahua; Chen, Xiaolin; Li, Pengcheng

    2014-04-01

    With an aim to discover novel chitosan derivatives with enhanced antifungal properties compared with chitosan. Diethyl dithiocarbamate chitosan (EtDTCCS) was investigated and its structure was well identified. The antifungal activity of EtDTCCS against Alternaria porri (A. porri), Gloeosporium theae sinensis Miyake (G. theae sinensis), and Stemphylium solani Weber (S. solani) was tested at 0.25, 0.5, and 1.0 mg/mL, respectively. Compared with plain chitosan, EtDTCCS shows better inhibitory effect with 93.2% inhibitory index on G. theae sinensis at 1.0 mg/mL, even stronger than for polyoxin (82.5%). It was inferred derivatives of this kind may find potential applications for the treatment of various crop-threatening diseases. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Growth modulation of fibroblasts by chitosan-polyvinyl pyrrolidone ...

    Indian Academy of Sciences (India)

    elicit inflammatory reactions which severely limit their use. (Ekholm et al 1999). ... modulation by a chitosan-PVP hydrogel, and suggest that the phenomenon may prove to be of ... All other chemicals or reagents used were of analytical grade.

  16. Study on preparation the egg yolk puff with chitosan

    Directory of Open Access Journals (Sweden)

    LI Hui

    2014-12-01

    Full Text Available This paper was studied chitosans with different degrees of deacetylation (70%,80%,90%,95% and different usages of chitosan that were added to research the effect of functional indexs in the egg yolk puff,such as calcium content and cholesterol content.Preliminarily chitosan was explored in the application of the Egg yolk puff.Text results showed that when the deacetylation degree of chitosan and its usage were 90% and 1% separately,the functional indexs and sensory quality of the Egg yolk puff can reach the equilibrium.Its calcium content was 76.2 mg/100 g,increased by 44.3 percent.Its cholesterol content was 290 mg/100 g,decreased by 35.1%.

  17. 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.

  18. A NOVEL APPROACH TO SYNTHESIZE CHITOSAN BEADS CROSSLINKED BY EPICHLOROHYDRIN

    Institute of Scientific and Technical Information of China (English)

    WANG Yongjian; BAI Shu; SUN Yan

    2001-01-01

    The present investigation describes a novel method for preparing spherical chitosan particles based on crosslinking with epichlorohydrin. Certain amount of pre-crosslinking agent was added to form chitosan gels by traditional inverse phase suspension polymerization. Then the gels were crosslinked by epichlorohydrin at basic condition to obtain chitosan beads. The effects of reaction conditions, such as crosslinking time, the amount of crosslinking agent and the NaOtt concentration,on the physical properties of the chitosan beads were investigated. The beads were found to have more amino groups in the polymer chains than the beads crosslinked by glutaraldehyde. The capacity for copper ions is as high as 40mg/g. The beads have good mechanical strength and can be reused.

  19. A NOVEL APPROACH TO SYNTHESIZE CHITOSAN BEADS CROSSLINKED BY EPICHLOROHYDRIN

    Institute of Scientific and Technical Information of China (English)

    WANGYongjina; BAIShu; 等

    2001-01-01

    The present investigation describes a novel method for preparing spherical chitosan particles based on crosslinking with epichlorohydrin.Certain amount of pre-crosslinking agent was added to form chitosan gels by traditional inverse phase suspension polymerization.Then the gels were crosslinked by epichlorohydrin at basic condition to obtain chitosan beads.The effects of reaction conditions,such as crosslinking time,the amount of crosslinking agent and the NaOH concentration,on the physical properties of the chitosan beads were investigated.The beads were found to have more amino groups in the polymer chains than the beads crosslinked by glutaraldehyde.The capacity for copper ions in as high as 40mg/g,The beads have good mechanical strength and can be reused.

  20. The dispersion of fine chitosan particles by beads-milling

    Science.gov (United States)

    Rochima, Emma; Utami, Safira; Hamdani, Herman; Azhary, Sundoro Yoga; Praseptiangga, Danar; Joni, I. Made; Panatarani, Camellia

    2018-02-01

    This research aimed to produce fine chitosan particles from a crab shell waste by beads-milling method by two different concentration of PEG as dispersing agent (150 and 300 wt. %). The characterization was performed to obtain the size and size distribution, the characteristics of functional groups and the degree of deacetylation. The results showed that the chitosan fine particles was obtained with a milling time 120 minutes with the best concentration of PEG 400 150 wt. %. The average particle size of the as-prepared suspension is 584 nm after addition of acetic acid solution (1%, v/v). Beads milling process did not change the glucosamine and N-acetylglucosamine content on chitosan structure which is indicated by degree of deacetylation higher than 70%. It was concluded that beads milling process can be applied to prepare chitosan fineparticles by proper adjustment in the milling time, pH and dosage of dispersing agent.

  1. Synthesis, characterization and antibacterial activity of new fluorescent chitosan derivatives

    Czech Academy of Sciences Publication Activity Database

    Přichystalová, H.; Almonasy, N.; Abdel-Mohsen, A. M.; Abdel-Rahman, R. M.; Fouda, M. M. G.; Vojtova, L.; Kobera, Libor; Spotz, Z.; Burgert, L.; Jancar, J.

    2014-01-01

    Roč. 65, April (2014), s. 234-240 ISSN 0141-8130 Institutional support: RVO:61389013 Keywords : chitosan derivatives * fluorescence * antibacterial activity Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.858, year: 2014

  2. Tailoring Functional Chitosan-based Composites for Food Applications.

    Science.gov (United States)

    Nunes, Cláudia; Coimbra, Manuel A; Ferreira, Paula

    2018-03-08

    Chitosan-based functional materials are emerging for food applications. The covalent bonding of molecular entities demonstrates to enhance resistance to the typical acidity of food assigning mechanical and moisture/gas barrier properties. Moreover, the grafting to chitosan of some functional molecules, like phenolic compounds or essential oils, gives antioxidant, antimicrobial, among others properties to chitosan. The addition of nanofillers to chitosan and other biopolymers improves the already mentioned required properties for food applications and can attribute electrical conductivity and magnetic properties for active and intelligent packaging. Electrical conductivity is a required property for the processing of food at low temperature using electric fields or for sensors application. © 2018 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Bromine pretreated chitosan for adsorption of lead (II) from water

    Indian Academy of Sciences (India)

    isotherm and maximum sorption capacity of 30% bromine pretreated chitosan sorbent was 1·755 g/kg with 85–. 90% lead .... C by applying Lagergren first ... Lead (II) ions concentrations were determined by using an .... following equation.

  4. Chitosan-based delivery systems for protein therapeutics and antigens

    NARCIS (Netherlands)

    Amidi, M.; Mastrobattista, E.; Jiskoot, W.; Hennink, W.E.

    Therapeutic peptides/proteins and protein-based antigens are chemically and structurally labile compounds, which are almost exclusively administered by parenteral injections. Recently, non-invasive mucosal routes have attracted interest for administration of these biotherapeutics. Chitosan-based

  5. Alginate-Chitosan Particulate System for Sustained Release of ...

    African Journals Online (AJOL)

    Erah

    1School of Pharmacy and Health Sciences, International Medical University, Kuala Lumpur, Malaysia, 2Division of ... Both calcium alginate beads and the beads treated with chitosan failed to release ..... also found to fit the classical power law.

  6. Reactivity of chitosan derivatives and their interaction with guanine ...

    Indian Academy of Sciences (India)

    Density functional theory; hydrogen bonding; chitosan derivative; guanine; solvent effect. 1. Introduction .... Out of different models for accounting the solva- tion energies ..... Authors thank DST, New Delhi for financial support. (Grant No.

  7. Preparation of water soluble chitosan by hydrolysis using hydrogen peroxide.

    Science.gov (United States)

    Xia, Zhenqiang; Wu, Shengjun; Chen, Jinhua

    2013-08-01

    Chitosan is not soluble in water, which limits its wide application particularly in the medicine and food industry. In the present study, water soluble chitosan (WSC) was prepared by hydrolyzing chitosan using hydrogen peroxide under the catalysis of phosphotungstic acid in homogeneous phase. Factors affecting hydrolysis were investigated and the optimal hydrolysis conditions were determined. The WSC structure was characterized by Fourier transform infrared spectroscopy. The resulting products were composed of chitooligosaccharides of DP 2-9. The WSC content of the product and the yield were 94.7% and 92.3% (w/w), respectively. The results indicate that WSC can be effectively prepared by hydrolysis of chitosan using hydrogen peroxide under the catalysis of phosphotungstic acid. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Sodium Carboxymethyl Chitosan as a Fixative for Eau de Cologne

    African Journals Online (AJOL)

    Co., Ltd., Muang, Nonthaburi 11000, 3Division of Packaging Technology, Faculty of Agro-Industry, Chiang Mai .... EXPERIMENTAL. Materials. Shrimp chitosan with a degree of deacetylation > .... various active perfume compounds in 94085.

  9. A new route for chitosan immobilization onto polyethylene surface

    Czech Academy of Sciences Publication Activity Database

    Popelka, A.; Novák, I.; Lehocký, M.; Junkar, I.; Mozetič, M.; Kleinová, A.; Janigová, I.; Šlouf, Miroslav; Bílek, F.; Chodák, I.

    2012-01-01

    Roč. 90, č. 4 (2012), s. 1501-1508 ISSN 0144-8617 Institutional support: RVO:61389013 Keywords : immobilization * plasma treatment * chitosan Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.479, year: 2012

  10. Formulation and Evaluation of Chitosan-Based Ampicillin Trihydrate ...

    African Journals Online (AJOL)

    Erah

    Parameters such as the zeta potential, polydispersity, particle size, entrapment ... variety of materials such as proteins, polysaccharides and ... formation is usually based on electrostatic interaction between the amine group of chitosan and a ...

  11. Oral Methylated N-Aryl Chitosan Derivatives for Inducing Immune ...

    African Journals Online (AJOL)

    TM-CM-CS) and methylated N-(4-pyridinylmethyl) chitosan (TM-Py-CS), with Eqiva degree (equivalent degree) were studied by in vitro absorption enhancement on the transepithelial electrical resistance (TEER) in Caco-2 cell monolayers as ...

  12. Surface modification on silicon with chitosan and biological research

    International Nuclear Information System (INIS)

    Lue Xiaoying; Cui Wei; Huang Yan; Zhao Yi; Wang Zhigong

    2009-01-01

    The aim of the present study was to investigate the effect of chitosan modification of silicon (Si) on protein adsorption, cell adhesion and cell proliferation. Chitosan was first immobilized on the Si surface through a (3-aminopropyl)triethoxysilane (APTES) bridge. The surface was then characterized by contact angle measurement, atomic force microscopy (AFM), x-ray photoelectron spectroscopy (XPS) and energy dispersive x-ray spectroscopy (EDX). The amount of protein adsorbed on the native Si and chitosan-modified Si surface was evaluated by a modified Coomassie brilliant blue (CBB) protein assay. The adhesion and proliferation behavior of L-929 and pc12 cells were then assessed by microscopy and methylthiazoltetrazolium (MTT) tests. The results showed that the chitosan modification could resist protein adsorption and inhibit the adhesion and proliferation of two kinds of cells on Si.

  13. Drug delivery glucantime in PVP/chitosan membranes

    International Nuclear Information System (INIS)

    Oliveira, Maria J.A.; Lugao, Ademar B.; Parra, Duclerc F.; Amato, Valdir S.

    2015-01-01

    The current study of polymer science considers the area of biomedical application very important to establish developments in new polymeric materials. Examples of that are hydrogels for controlled release of drugs. In this work, hydrogels of poly (N-2-vinil-pyrrolidone) (PVP) containing chitosan and clay nanoparticles were obtained and characterized to investigate chitosan influence on Glucantime drug delivery. The matrixes were crosslinked by gamma irradiation process with doses of 25 kGy. Hydrogels morphologies were observed by X Ray diffraction (DRX). Atomic Force Microscopy (AFM) and swelling kinetic at 22 °C to study the capacity of water retention and, finally, drug delivery tests were performed 'in vitro'. The system showed higher gel fraction for the matrix with 1.0% of clay and 0.5% of chitosan. In this case, besides the interactions of clay ions with PVP, there are interactions of chitosan amine group with PVP amide group. (author)

  14. PLA/chitosan/keratin composites for biomedical applications

    International Nuclear Information System (INIS)

    Tanase, Constantin Edi; Spiridon, Iuliana

    2014-01-01

    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. Towards a selective adsorbent for arsenate and selenite in the presence of phosphate: Assessment of adsorption efficiency, mechanism, and binary separation factors of the chitosan-copper complex.

    Science.gov (United States)

    Yamani, Jamila S; Lounsbury, Amanda W; Zimmerman, Julie B

    2016-01-01

    The potential for a chitosan-copper polymer complex to select for the target contaminants in the presence of their respective competitive ions was evaluated by synthesizing chitosan-copper beads (CCB) for the treatment of (arsenate:phosphate), (selenite:phosphate), and (selenate:sulfate). Based on work by Rhazi et al., copper (II) binds to the amine moiety on the chitosan backbone as a monodentate complex (Type I) and as a bidentate complex crosslinking two polymer chains (Type II), depending on pH and copper loading. In general, the Type I complex exists alone; however, beyond threshold conditions of pH 5.5 during synthesis and a copper loading of 0.25 mol Cu(II)/mol chitosan monomer, the Type I and Type II complexes coexist. Subsequent chelation of this chitosan-copper ligand to oxyanions results in enhanced and selective adsorption of the target contaminants in complex matrices with high background ion concentrations. With differing affinities for arsenate, selenite, and phosphate, the Type I complex favors phosphate chelation while the Type II complex favors arsenate chelation due to electrostatic considerations and selenite chelation due to steric effects. No trend was exhibited for the selenate:sulfate system possibly due to the high Ksp of the corresponding copper salts. Binary separation factors, α12, were calculated for the arsenate-phosphate and selenite-phosphate systems, supporting the mechanistic hypothesis. While, further research is needed to develop a synthesis method for the independent formation of the Type II complexes to select for target contaminants in complex matrices, this work can provide initial steps in the development of a selective adsorbent. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Design of peptide-conjugated glycol chitosan nanoparticles for near infrared fluorescent (NIRF) in vivo imaging of bladder tumors

    Science.gov (United States)

    Key, Jaehong; Dhawan, Deepika; Knapp, Deborah W.; Kim, Kwangmeyung; Kwon, Ick Chan; Choi, Kuiwon; Leary, James F.

    2012-03-01

    Enhanced permeability and retention (EPR) effects for tumor treatment have been utilized as a representative strategy to accumulate untargeted nanoparticles in the blood vessels around tumors. However, the EPR effect itself was not sufficient for the nanoparticles to penetrate into cancer cells. For the improvement of diagnosis and treatment of cancer using nanoparticles, many more nanoparticles need to specifically enter cancer cells. Otherwise, can leave the tumor area and not contribute to treatment. In order to enhance the internalization process, specific ligands on nanoparticles can help their specific internalization in cancer cells by receptor-mediated endocytosis. We previously developed glycol chitosan based nanoparticles that suggested a promising possibility for in vivo tumor imaging using the EPR effect. The glycol chitosan nanoparticles showed a long circulation time beyond 1 day and they were accumulated predominantly in tumor. In this study, we evaluated two peptides for specific targeting and better internalization into urinary bladder cancer cells. We conjugated the peptides on to the glycol chitosan nanoparticles; the peptide-conjugated nanoparticles were also labeling with near infrared fluorescent (NIRF) dye, Cy5.5, to visualize them by optical imaging in vivo. Importantly real-time NIRF imaging can also be used for fluorescence (NIRF)-guided surgery of tumors beyond normal optical penetration depths. The peptide conjugated glycol chitosan nanoparticles were characterized with respect to size, stability and zeta-potential and compared with previous nanoparticles without ligands in terms of their internalization into bladder cancer cells. This study demonstrated the possibility of our nanoparticles for tumor imaging and emphasized the importance of specific targeting peptides.

  17. A bioprintable form of chitosan hydrogel for bone tissue engineering.

    Science.gov (United States)

    Demirtaş, Tuğrul Tolga; Irmak, Gülseren; Gümüşderelioğlu, Menemşe

    2017-07-13

    Bioprinting can be defined as 3D patterning of living cells and other biologics by filling and assembling them using a computer-aided layer-by-layer deposition approach to fabricate living tissue and organ analogs for tissue engineering. The presence of cells within the ink to use a 'bio-ink' presents the potential to print 3D structures that can be implanted or printed into damaged/diseased bone tissue to promote highly controlled cell-based regeneration and remineralization of bone. In this study, it was shown for the first time that chitosan solution and its composite with nanostructured bone-like hydroxyapatite (HA) can be mixed with cells and printed successfully. MC3T3-E1 pre-osteoblast cell laden chitosan and chitosan-HA hydrogels, which were printed with the use of an extruder-based bioprinter, were characterized by comparing these hydrogels to alginate and alginate-HA hydrogels. Rheological analysis showed that all groups had viscoelastic properties. It was also shown that under simulated physiological conditions, chitosan and chitosan-HA hydrogels were stable. Also, the viscosity values of the bio-solutions were in an applicable range to be used in 3D bio-printers. Cell viability and proliferation analyses documented that after printing with bio-solutions, cells continued to be viable in all groups. It was observed that cells printed within chitosan-HA composite hydrogel had peak expression levels for early and late stages osteogenic markers. It was concluded that cells within chitosan and chitosan-HA hydrogels had mineralized and differentiated osteogenically after 21 days of culture. It was also discovered that chitosan is superior to alginate, which is the most widely used solution preferred in bioprinting systems, in terms of cell proliferation and differentiation. Thus, applicability and printability of chitosan as a bio-printing solution were clearly demonstrated. Furthermore, it was proven that the presence of bone-like nanostructured HA in

  18. Effect of water-soluble P-chitosan and S-chitosan on human primary osteoblasts and giant cell tumor of bone stromal cells

    Energy Technology Data Exchange (ETDEWEB)

    Tang, T; Zhang, G; PY Lau, Carol; Zheng, L Z; Xie, X H; Wang, X L; Patrick, Y; Qin, L; Kumta, Shekhar M [Department of Orthopaedics and Traumatology, Chinese University of Hong Kong (Hong Kong); Wang, X H; He, K, E-mail: kumta@cuhk.edu.hk [Department of Mechanical Engineering, Institute of Bio-manufacturing Engineering, Tsinghua University, Beijing (China)

    2011-02-15

    Water-soluble phosphorylated chitosan (P-chitosan) and disodium (1 {yields} 4)-2-deoxy-2-sulfoamino-{beta}-D-glucopyranuronan (S-chitosan) are two chemically modified chitosans. In this study, we found that P-chitosan significantly promotes cell proliferation of both human primary osteoblasts (OBs) and the OB like stromal cell component of the giant cell tumor of bone (GCTB) cells at the concentration from 125 to 1000 {mu}g ml{sup -1} at all time points of 1, 3, 5 and 7 days after treatment. Further investigation of the osteogenic effect of the P-chitosan suggested that it regulates the levels of osteoclastogenic factors, receptor activator of nuclear factor kappa B ligand and osteoprotegerin expression. An interesting finding is that S-chitosan at lower concentration (100 {mu}g ml{sup -1}) stimulates cell proliferation while a higher dose (1000 {mu}g ml{sup -1}) of S-chitosan inhibits it. The inhibitory effect of S-chitosan on human primary GCT stromal cells was greater than that of OBs (p < 0.05). Taken together, our findings elucidated the osteogenic effect of P-chitosan and the varying effects of S-chitosan on the proliferation of human primary OBs and GCT stromal cells and provided us the rationale for the construction of novel bone repair biomaterials with the dual properties of bone induction and bone tumor inhibition.

  19. Conjugation of Inulin Improves Anti-Biofilm Activity of Chitosan

    OpenAIRE

    Guiqiang Zhang; Jing Liu; Ruilian Li; Siming Jiao; Cui Feng; Zhuo A. Wang; Yuguang Du

    2018-01-01

    Bacteria biofilm helps bacteria prevent phagocytosis during infection and increase resistance to antibiotics. Staphylococcus aureus is a Gram-positive pathogenic bacterium and is tightly associated with biofilm-related infections, which have led to great threat to human health. Chitosan, the only cationic polysaccharide in nature, has been demonstrated to have antimicrobial and anti-biofilm activities, which, however, require a relative high dosage of chitosan. Moreover, poor water solubility...

  20. FTIR studies of chitosan acetate based polymer electrolytes

    International Nuclear Information System (INIS)

    Osman, Z.; Arof, A.K.

    2003-01-01

    Chitosan is the product when partially deacetylated chitin dissolves in dilute acetic acid. As such, depending on the degree of deacetylation, the carbonyl, C=O-NHR band can be observed at ∼1670 cm -1 and the amine, NH 2 band at 1590 cm -1 . When lithium triflate is added to chitosan to form a film of chitosan acetate-salt complex, the bands assigned to chitosan in the complex and the spectrum as a whole shift to lower wavenumbers. The carbonyl band is observed to shift to as low as 1645 cm -1 and the amine band to as low as 1560 cm -1 . These indicate chitosan-salt interactions. Also present are the bands due to lithium triflate i.e. ∼761, 1033, 1182 and 1263 cm -1 . When chitosan and ethylene carbonate (EC) are dissolved in acetic acid to form a film of plasticized chitosan acetate, the bands in the infrared spectrum of the films do not show any significant shift indicating that EC does not interact with chitosan. EC-LiCF 3 SO 3 interactions are indicated by the shifting of the C-O bending band from 718 cm -1 in the spectrum of EC to 725 cm -1 in the EC-salt spectrum. The Li + -EC is also evident in the ring breathing region at 893 cm -1 in the pure EC spectrum. This band has shifted to 898 cm -1 in the EC-salt spectrum. C=O stretching in the doublet observed at 1774 and 1803 cm -1 in the spectrum of pure EC has shifted to 1777 and 1808 cm -1 in the EC-salt spectrum

  1. Chitosan nanoparticles as drug delivery carriers for biomedical engineering

    International Nuclear Information System (INIS)

    Shi, L.E.S.; Chen, M.; XINF, L.Y.; Guo, X.F.; Zhao, L.M.

    2011-01-01

    Chitosan is a rather abundant material, which has been widely used in food industrial and bioengineering aspects, including in encapsulating active food ingredients, in enzyme immobilization, and as a carrier for drug delivery, due to its significant biological and chemical properties such as biodegradable, biocompatible, bioactive and polycationic. This review discussed preparation and applications of chitosan nanoparticles in the biomedical engineering field, namely as a drug delivery carrier for biopharmaceuticals. (author)

  2. Properties of emulsions stabilised by sodium caseinate–chitosan complexes

    NARCIS (Netherlands)

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

    2012-01-01

    Oil-in-water emulsions (10%, w/w, oil) were prepared at pH 5.7 by using electrostatically formed complexes of 0.5% (w/w) sodium caseinate (Na-CAS) and 0–0.6% (w/w) chitosan. Emulsions stabilized by complexes with increased levels of chitosan (>0.2% w/w) had a smaller average droplet size and

  3. Chitosan and Nanohydroxyapatite Roles in Physical and Chemical Characteristics of Gelatin/Chitosan/Nanohydroxyapatite Microspheres

    Directory of Open Access Journals (Sweden)

    S. Bagheri-Khoulenjani

    2010-12-01

    Full Text Available The effects of chitosan/biopolymer (C/P and nanohydroxyapatite/ biopolymer (nHA/P weight ratios on particle size and its uniformity, cross-linking density and NH2 content of nano-hydroxyapatite/chitosan/gelatin (nHA/C/G microspheres were investigated. Microspheres were fabricated using water-in-oil emulsion. Cross-linking of microspheres was performed using water soluble carbodiimide. Particle size and its uniformity were evaluated using an optical microscope. The morphology of microspheres was studied by scanning electron microscopy. The obtained data from particle size measurements revealed that increments in C/P ratio increased the particle size while reducing its uniformity, and increased the NH2 content and cross linking density of the microspheres. It was shown that incremental increase in nHA/P ratio increased the particle size and its uniformity and reduced the NH2 content and cross-linking density of the microspheres.Morphological studies showed that the fabricated microspheres had spherical shape in medium level of C/P ratio and nHA/P ratio. However, increasing in chitosan/biopolymer ratio induced some micro-cracks into the structure of microspheres.

  4. Chitosan-thioglycolic acid as a versatile antimicrobial agent.

    Science.gov (United States)

    Geisberger, Georg; Gyenge, Emina Besic; Hinger, Doris; Käch, Andres; Maake, Caroline; Patzke, Greta R

    2013-04-08

    As functionalized chitosans hold great potential for the development of effective and broad-spectrum antibiotics, representative chitosan derivatives were tested for antimicrobial activity in neutral media: trimethyl chitosan (TMC), carboxy-methyl chitosan (CMC), and chitosan-thioglycolic acid (TGA; medium molecular weight: MMW-TGA; low molecular weight: LMW-TGA). Colony forming assays indicated that LMW-TGA displayed superior antimicrobial activity over the other derivatives tested: a 30 min incubation killed 100% Streptococcus sobrinus (Gram-positive bacteria) and reduced colony counts by 99.99% in Neisseria subflava (Gram-negative bacteria) and 99.97% in Candida albicans (fungi). To elucidate LMW-TGA effects at the cellular level, microscopic studies were performed. Use of fluorescein isothiocyanate (FITC)-labeled chitosan derivates in confocal microscopy showed that LMW-TGA attaches to microbial cell walls, while transmission electron microscopy indicated that this derivative severely affects cell wall integrity and intracellular ultrastructure in all species tested. We therefore propose LMW-TGA as a promising and effective broad-band antimicrobial compound.

  5. Lactic acid demineralization of shrimp shell and chitosan synthesis

    Directory of Open Access Journals (Sweden)

    Alewo Opuada AMEH

    2015-05-01

    Full Text Available The use of lactic acid was compared to hydrochloric acid for shrimp shell demineralization in chitosan synthesis. Five different acid concentrations were considered for the study: 1.5M, 3.0M, 4.5M, 6.0M and 7.5M. After demineralization, the shrimp shell were deproteinized and subsequently deacetylated to produce chitosan using sodium hydroxide solution. The synthesized chitosan samples were characterized using solubility, FTIR, SEM, XRD and viscosity. The SEM, FTIR and XRD analysis indicated that chitosan was synthesized with a high degree of deacetylation (83.18±2.11 when lactic acid was used and 84.2±5.00 when HCl was used. The degree of deacetylation and the molecular weight of the chitosan samples were also estimated. ANOVA analysis (at 95% confidence interval indicated that acid type and concentration did not significantly affect the solubility, degree of deacetylation, viscosity and molecular weight of the chitosan within the range considered.

  6. Physicochemical and functional characteristics of radiation-processed shrimp chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Ocloo, F.C.K., E-mail: fidelis_ocloo@yahoo.co [Biotechnology and Nuclear Agriculture Research Institute, Ghana Atomic Energy Commission, P.O. Box LG 80, Legon (Ghana); Quayson, E.T. [Department of Biochemistry, University of Cape Coast, Cape Coast (Ghana); Adu-Gyamfi, A.; Quarcoo, E.A.; Asare, D. [Biotechnology and Nuclear Agriculture Research Institute, Ghana Atomic Energy Commission, P.O. Box LG 80, Legon (Ghana); Serfor-Armah, Y. [National Nuclear Research Institute, Ghana Atomic Energy Commission, P.O. Box LG 80, Legon (Ghana); Woode, B.K. [Department of Biochemistry, University of Cape Coast, Cape Coast (Ghana)

    2011-07-15

    The effects of gamma irradiation on chitosan samples were determined in terms of physicochemical and functional properties. Shrimp chitosan was extracted from shell using a chemical process involving demineralization, deproteinization, decolorization and deacetylation. Commercial snow chitosan was also used. Samples (in a solid state) were given irradiation dose of 25 kGy at a dose rate of 1.1013 kGy/h in air and 0 kGy samples were used as controls. Results showed that moisture contents were between 8.690% and 13.645%. There were no significant differences (P>0.05) in the degree of deacetylation of the chitosan samples. Significant differences (P<0.05) were observed in the viscosity and viscosity-average molecular weight of the chistosan samples. Viscosity and molecular weight decreased when the samples were given the irradiation dose of 25 kGy. Chitosan samples had low antioxidant activity compared with BHT. Water binding capacity ranged from 582.40% to 656.75% and fat binding capacity was between 431.00% and 560.55%. Irradiation had a major effect on the viscosity and the viscosity-average molecular weight of the chitosan samples.

  7. The Multifunctional Role of Chitosan in Horticultural Crops; A Review

    Directory of Open Access Journals (Sweden)

    Rahat Sharif

    2018-04-01

    Full Text Available Chitosan is a naturally occurring compound and is commercially produced from seafood shells. It has been utilized in the induction of the defense system in both pre and post-harvest fruits and vegetables against fungi, bacteria, viruses, and other abiotic stresses. In addition to that, chitosan effectively improves the physiological properties of plants and also enhances the shelf life of post-harvest produces. Moreover, chitosan treatment regulates several genes in plants, particularly the activation of plant defense signaling pathways. That includes the elicitation of phytoalexins and pathogenesis-related (PR protein. Besides that, chitosan has been employed in soil as a plant nutrient and has shown great efficacy in combination with other industrial fertilizers without affecting the soil’s beneficial microbes. Furthermore, it is helpful in reducing the fertilizer losses due to its coating ability, which is important in keeping the environmental pollution under check. Based on exhibiting such excellent properties, there is a striking interest in using chitosan biopolymers in agriculture systems. Therefore, our current review has been centered upon the multiple roles of chitosan in horticultural crops that could be useful in future crop improvement programs.

  8. Physicochemical and functional characteristics of radiation-processed shrimp chitosan

    International Nuclear Information System (INIS)

    Ocloo, F.C.K.; Quayson, E.T.; Adu-Gyamfi, A.; Quarcoo, E.A.; Asare, D.; Serfor-Armah, Y.; Woode, B.K.

    2011-01-01

    The effects of gamma irradiation on chitosan samples were determined in terms of physicochemical and functional properties. Shrimp chitosan was extracted from shell using a chemical process involving demineralization, deproteinization, decolorization and deacetylation. Commercial snow chitosan was also used. Samples (in a solid state) were given irradiation dose of 25 kGy at a dose rate of 1.1013 kGy/h in air and 0 kGy samples were used as controls. Results showed that moisture contents were between 8.690% and 13.645%. There were no significant differences (P>0.05) in the degree of deacetylation of the chitosan samples. Significant differences (P<0.05) were observed in the viscosity and viscosity-average molecular weight of the chistosan samples. Viscosity and molecular weight decreased when the samples were given the irradiation dose of 25 kGy. Chitosan samples had low antioxidant activity compared with BHT. Water binding capacity ranged from 582.40% to 656.75% and fat binding capacity was between 431.00% and 560.55%. Irradiation had a major effect on the viscosity and the viscosity-average molecular weight of the chitosan samples.

  9. Development of thermoplastic starch blown film by incorporating plasticized chitosan.

    Science.gov (United States)

    Dang, Khanh Minh; Yoksan, Rangrong

    2015-01-22

    The objective of the present work was to improve blown film extrusion processability and properties of thermoplastic starch (TPS) film by incorporating plasticized chitosan, with a content of 0.37-1.45%. The effects of chitosan on extrusion processability and melt flow ability of TPS, as well as that on appearance, optical properties, thermal properties, viscoelastic properties and tensile properties of the films were investigated. The possible interactions between chitosan and starch molecules were evaluated by FTIR and XRD techniques. Chitosan and starch molecules could interact via hydrogen bonds, as confirmed from the blue shift of OH bands and the reduction of V-type crystal formation. Although the incorporation of chitosan caused decreased extensibility and melt flow ability, as well as increased yellowness and opacity, the films possessed better extrusion processability, increased tensile strength, rigidity, thermal stability and UV absorption, as well as reduced water absorption and surface stickiness. The obtained TPS/chitosan-based films offer real potential application in the food industry, e.g. as edible films. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Development of an injectable chitosan/marine collagen composite gel

    International Nuclear Information System (INIS)

    Wang Wei; Itoh, Soichiro; Aizawa, Tomoyasu; Demura, Makoto; Okawa, Atsushi; Sakai, Katsuyoshi; Ohkuma, Tsuneo

    2010-01-01

    A chitosan/marine-originated collagen composite has been developed. This composite gel was characterized and its biocompatibility, as well as an inflammatory reaction, was observed. The chitosan gel including N-3-carboxypropanoil-6-O-(carboxymethyl) chitosan of 3 mol%, 6-O-(carboxymethyl) chitosan of 62 mol% and 6-O-(carboxymethyl) chitin of 35 mol% was prepared and compounded with the salmon atelocollagen (SA) gel at different mixture ratios. The composite gels were injected subcutaneously in to the back of rats. The specimens were harvested for a histological survey as well as a tumor necrosis factor-alpha (TNF-α) assay by ELISA. The inflammatory cell infiltration and release of TNF-α were successively controlled low with the ratio of SA to chitosan at 10:90 or 20:80. The SA gel first, within 2 weeks, and then chitosan in the composite gel were slowly absorbed after implantation, followed by soft tissue formation. It is expected that this composite gel will be available as a carrier for tissue filler and drug delivery systems.

  11. 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 muco......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 pH 5...

  12. Molecular interactions in gelatin/chitosan composite films.

    Science.gov (United States)

    Qiao, Congde; Ma, Xianguang; Zhang, Jianlong; Yao, Jinshui

    2017-11-15

    Gelatin and chitosan were mixed at different mass ratios in solution forms, and the rheological properties of these film-forming solutions, upon cooling, were studied. The results indicate that the significant interactions between gelatin and chitosan promote the formation of multiple complexes, reflected by an increase in the storage modulus of gelatin solution. Furthermore, these molecular interactions hinder the formation of gelatin networks, consequently decreasing the storage modulus of polymer gels. Both hydrogen bonds and electrostatic interactions are formed between gelatin and chitosan, as evidenced by the shift of the amide-II bands of polymers. X-ray patterns of composite films indicate that the contents of triple helices decrease with increasing chitosan content. Only one glass transition temperature (T g ) was observed in composite films with different composition ratios, and it decreases gradually with an increase in chitosan proportion, indicating that gelatin and chitosan have good miscibility and form a wide range of blends. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Functionalized and graft copolymers of chitosan and its pharmaceutical applications.

    Science.gov (United States)

    Bhavsar, Chintan; Momin, Munira; Gharat, Sankalp; Omri, Abdelwahab

    2017-10-01

    Chitosan is the second most abundant natural polysaccharide. It belongs a family of polycationic polymers comprised of repetitive units of glucosamine and N-acetylglucosamine. Its biodegradability, nontoxicity, non-immunogenicity and biocompatibility along with properties like mucoadhesion, fungistatic and bacteriogenic have made chitosan an appreciated polymer with numerous applications in the pharmaceutical, comestics and food industry. However, the limited solubility of chitosan at alkaline and neutral pH limits its widespread commercial use. This can be circumvented by fabrication of chitosan by graft copolymerization with acyl, alkyl, monomeric and polymeric moieties. Areas covered: Modifications like quarterization, thiolation, acylation and grafting result in copolymers with higher mucoadhesion strength, increased hydrophobic interactions (advantageous in hydrophobic drug entrapment), and increased solubility in alkaline pH, the ability for adsorption of metal ions, protein and peptide delivery and nutrient delivery. Insights on methods of polymerization, including atomic transfer radical polymerization and click chemistry are discussed. Applications of such modified chitosan copolymers in medical and surgical, and drug delivery, including nasal, oral and buccal delivery have also been covered. Expert opinion: Despite a number of successful investigations, commercialization of chitosan copolymers still remains a challenge. Further advancements in polymerization techniques may address the unmet needs of the healthcare industry.

  14. Study on chitosan film properties as a green dielectric

    Science.gov (United States)

    Nainggolan, I.; Nasution, T. I.; Putri, S. R. E.; Azdena, D.; Balyan, M.; Agusnar, H.

    2018-02-01

    Chitosan film dielectrics to produce an electrostatic capacitor were prepared by the solution cast technique. The charging and discharging of the capacitor were done using RC series circuit with DC voltage supply because chitosan has bipolar properties. First testing was by varying supply voltage of 1, 3, 5, 10 and 15 V, respectively, and could be determined that the most effective voltage for chitosan film can be well polarised is 5 V. The results of second testing for the use of 5 V supply showed that the capacitance of a chitosan film capacitor decreased with the increase in load value. For loads of 100, 1K, 10K, 100K and 1M Ω, the capacitance values of the chitosan film capacitor were 3.1725, 0.4136, 0.05379, 0.007917 and 0.001522 F, respectively. It was also found that the increase in voltage of the capacitor at charging process was faster for the lower load. Therefore, the research result has corresponded to the general formula that used to calculate the capacitance value and thus, the biopolymer chitosan has potential as a sustainable green dielectric.

  15. In Situ Mineralization of Magnetite Nanoparticles in Chitosan Hydrogel

    Science.gov (United States)

    Wang, Yongliang; Li, Baoqiang; Zhou, Yu; Jia, Dechang

    2009-09-01

    Based on chelation effect between iron ions and amino groups of chitosan, in situ mineralization of magnetite nanoparticles in chitosan hydrogel under ambient conditions was proposed. The chelation effect between iron ions and amino groups in CS-Fe complex, which led to that chitosan hydrogel exerted a crucial control on the magnetite mineralization, was proved by X-ray photoelectron spectrum. The composition, morphology and size of the mineralized magnetite nanoparticles were characterized by X-ray diffraction, Raman spectroscopy, transmission electron microscopy and thermal gravity. The mineralized nanoparticles were nonstoichiometric magnetite with a unit formula of Fe2.85O4 and coated by a thin layer of chitosan. The mineralized magnetite nanoparticles with mean diameter of 13 nm dispersed in chitosan hydrogel uniformly. Magnetization measurement indicated that superparamagnetism behavior was exhibited. These magnetite nanoparticles mineralized in chitosan hydrogel have potential applications in the field of biotechnology. Moreover, this method can also be used to synthesize other kinds of inorganic nanoparticles, such as ZnO, Fe2O3 and hydroxyapatite.

  16. In Situ Mineralization of Magnetite Nanoparticles in Chitosan Hydrogel

    Directory of Open Access Journals (Sweden)

    Wang Yongliang

    2009-01-01

    Full Text Available Abstract Based on chelation effect between iron ions and amino groups of chitosan, in situ mineralization of magnetite nanoparticles in chitosan hydrogel under ambient conditions was proposed. The chelation effect between iron ions and amino groups in CS–Fe complex, which led to that chitosan hydrogel exerted a crucial control on the magnetite mineralization, was proved by X-ray photoelectron spectrum. The composition, morphology and size of the mineralized magnetite nanoparticles were characterized by X-ray diffraction, Raman spectroscopy, transmission electron microscopy and thermal gravity. The mineralized nanoparticles were nonstoichiometric magnetite with a unit formula of Fe2.85O4and coated by a thin layer of chitosan. The mineralized magnetite nanoparticles with mean diameter of 13 nm dispersed in chitosan hydrogel uniformly. Magnetization measurement indicated that superparamagnetism behavior was exhibited. These magnetite nanoparticles mineralized in chitosan hydrogel have potential applications in the field of biotechnology. Moreover, this method can also be used to synthesize other kinds of inorganic nanoparticles, such as ZnO, Fe2O3and hydroxyapatite.

  17. A study of sorption of pertechnetate anion on chitosan

    International Nuclear Information System (INIS)

    Pivarciova, L.; Rosskopfova, O.; Rajec, P.; Galambos, M.

    2015-01-01

    Chitosan is one of the natural materials of biological origin. The sorption of pertechnetate anions from aqueous solutions on chitosan was studied in a batch system. This work was aimed to study influence of the contact time, effect of pH and effect of different ions on sorption of pertechnetate anions on chitosan. This sorbent was characterized by BET-surface area and potentiometric titration. The point of zero charge (pH pzc ) was at pH=7.15. The highest percentage of technetium sorption on chitosan was near pH 3. The adsorption capacity of chitosan decreased with increase in pH value above 3. In the initial pH range of 4-10, final pHs are the same. The selectivity of chitosan for these cations with concentration above 1·10 -3 mol·dm -3 was in the order Na + > Ca 2+ > Fe 3+ > Fe 2+ . The competition effect of (SO 4 ) 2- towards TcO 4 - sorption was stronger than the competition effect (ClO 4 ) - of ions. (authors)

  18. 166Ho-chitosan as a radiation synovectomy agent - biocompatibility study of 166Ho-chitosan in rabbits

    International Nuclear Information System (INIS)

    Kim, Sug Jun; Lee, Soo Yong; Jeon, Dae Geun; Lee Jong Seok

    1997-01-01

    Radiation synovectomy is a noninvasive therapy that has been investigated as an alternative to surgical synovectomy. It is been successfully employed in the treatment of synovitis in rheumatoid arthrits and other inflammatory arthropathies. We developed the 166 Ho-chitosan complex for possible use as a radiation synovectomy agent. Holmium is the more practical isotope based on its higher radioactivity and logner half-life. And isotope based on its higher radioactivity and logner half-life. And chitosan is ideal and suitable particles based on its soluble and biodegradable characteristics. So we investigated the biocompatibility of the 166 Ho-chitosan complex to evaluated the suitability as a radiation synovectomy agent. In this study, we performed in vivo and in vitro stability test and biodistribution test. Our results indicate that 166 Ho-chitosan may be an effective radiopharmaceutical for radiation synovectomy. (author). 30 refs., 7 tabs

  19. {sup 166}Ho-chitosan as a radiation synovectomy agent - biocompatibility study of {sup 166}Ho-chitosan in rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sug Jun; Lee, Soo Yong; Jeon, Dae Geun; Seok, Lee Jong [Korea Cancer Center Hospital, Seoul (Korea, Republic of)

    1997-01-01

    Radiation synovectomy is a noninvasive therapy that has been investigated as an alternative to surgical synovectomy. It is been successfully employed in the treatment of synovitis in rheumatoid arthrits and other inflammatory arthropathies. We developed the {sup 166}Ho-chitosan complex for possible use as a radiation synovectomy agent. Holmium is the more practical isotope based on its higher radioactivity and logner half-life. And isotope based on its higher radioactivity and logner half-life. And chitosan is ideal and suitable particles based on its soluble and biodegradable characteristics. So we investigated the biocompatibility of the {sup 166}Ho-chitosan complex to evaluated the suitability as a radiation synovectomy agent. In this study, we performed in vivo and in vitro stability test and biodistribution test. Our results indicate that {sup 166}Ho-chitosan may be an effective radiopharmaceutical for radiation synovectomy. (author). 30 refs., 7 tabs.

  20. Effect of moisture and chitosan layered silicate on morphology and properties of chitosan/layered silicates films

    International Nuclear Information System (INIS)

    Silva, J.R.M.B. da; Santos, B.F.F. dos; Leite, I.F.

    2014-01-01

    Thin chitosan films have been for some time an object of practical assessments. However, to obtain biopolymers capable of competing with common polymers a significant improvement in their properties is required. Currently, the technology of obtaining polymer/layered silicates nanocomposites has proven to be a good alternative. This work aims to evaluate the effect of chitosan content (CS) and layered silicates (AN) on the morphology and properties of chitosan/ layered silicate films. CS/AN bionanocomposites were prepared by the intercalation by solution in the proportion 1:1 and 5:1. Then were characterized by infrared spectroscopy (FTIR), diffraction (XRD) and X-ray thermogravimetry (TG). It is expected from the acquisition of films, based on different levels of chitosan and layered silicates, choose the best composition to serve as a matrix for packaging drugs and thus be used for future research. (author)

  1. Biological evaluation of silver nanoparticles incorporated into chitosan-based membranes

    NARCIS (Netherlands)

    Shao, J.; Yu, N.; Kolwijck, E.; Wang, B.; Tan, K.W.; Jansen, J.A.; Walboomers, X.F.; Yang, F.

    2017-01-01

    AIM: To evaluate the antibacterial potential and biological performance of silver nanoparticles in chitosan-based membranes. MATERIALS & METHODS: Electrospun chitosan/poly(ethylene oxide) membranes with different amounts of silver nanoparticles were evaluated for antibacterial properties and

  2. Investigating Effects of Gelatin-Chitosan Film on Culture of Bone Marrow Stromal Cells in Rat

    Directory of Open Access Journals (Sweden)

    A Karami joyani

    2015-02-01

    Conclusion: Results of proliferation,differentiation and apoptosis cultured BMSCs on a gelatin-chitosan film showed that gelatin-chitosan film can be used as a good model of a biodegradable scaffold in tissue engineering and cell therapy.

  3. Preliminary Studies on Antifungal Properties of Radiation Processed Chitosan from Crab Shells

    International Nuclear Information System (INIS)

    Ocloo, Fidelis C.K.; Adu-Gyamfi, Abraham; Quarcoo, Emmanuel A.; Asare, Daniel; Yaw, Serfor-Armah

    2010-01-01

    Chitosan extracted from sea crab shells was used to determine antifungal properties against Aspergillus niger. Chitosan powder irradiated at 100 kGy and dissolved in 1% acetic acid (v/v) with pH adjusted to approximately 6.0 was used in preparing chitosan concentrations of 2%, 1.5%, 1% and 0.5%. The agar dilution method was used to test the antifungal activity of the various chitosan solutions at concentrations of 0.20%, 0.15%, 0.10% and 0.05%. Both media containing irradiated and unirradiated chitosan inhibited the mycelial growth of Aspergillus niger and the degree of inhibition was dependent on the concentration of the chitosan in the fungal growth medium. Results show that the media containing irradiated chitosan inhibited the mycelia growth of Aspergillus niger to a greater extent than the media containing unirradiated chitosan. (author)

  4. Synthesis and characterization of Cis-5-Norbornene-2, 3-dicarboxylic anhydride-chitosan

    International Nuclear Information System (INIS)

    Ku Marshilla Ku Ishak; Zulkifli Ahmad; Hazizan Mohd Akil

    2009-01-01

    Chitosan was chemically modified with bulky structure, cis-5-norbornene-2, 3-dicarboxylic anhydride and the characteristic of this modified chitosan was studied. The resulting material was analyzed by FTIR, TGA, DSC, XRD and SEM to study the effect of N-acylation to the polysaccharide structure. FTIR results show that the anhydride monomer was successfully bound to amine group of chitosan. Thermal analysis of the modified structure provides the chitosan fibers with thermal stability while XRD and SEM show the lost of crystallinity of modified chitosan. XRD of modified chitosan shows broader peak pattern and a considerable increase in a dimension while SEM of chitosan presented the single particle morphology while norbornene-chitosan shows aggromolarate behaviour due to the hydrophobic nature of norbornene pendant group which induced aggromolaration of the particles in modified structure.(author)

  5. Utilization of Degraded Chitosan for Growth Promoter and Blossom Blight Disease Controls in Okra

    International Nuclear Information System (INIS)

    Kewsuwan, Prartana

    2010-01-01

    The experiment focus on the comparison of the effect of gamma radiation and chemical reagent on degradation of chitosan and preliminary test of degraded chitosan with different molecular weight as plant growth promoter of okra in potting experiment. (author)

  6. Antibacterial Characteristics and Activity of Water-Soluble Chitosan Derivatives Prepared by the Maillard Reaction

    Directory of Open Access Journals (Sweden)

    Ying-Chien Chung

    2011-10-01

    Full Text Available The antibacterial activity of water-soluble chitosan derivatives prepared by Maillard reactions against Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, Escherichia coli, Shigella dysenteriae, and Salmonella typhimurium was examined. Relatively high antibacterial activity against various microorganisms was noted for the chitosan-glucosamine derivative as compared to the acid-soluble chitosan. In addition, it was found that the susceptibility of the test organisms to the water-soluble chitosan derivative was higher in deionized water than in saline solution. Metal ions were also found to reduce the antibacterial activity of the water-soluble chitosan derivative on S. aureus. The marked increase in glucose level, protein content and lactate dehydrogenase (LDH activity was observed in the cell supernatant of S. aureus exposed to the water-soluble chitosan derivative in deionized water. The results suggest that the water-soluble chitosan produced by Maillard reaction may be a promising commercial substitute for acid-soluble chitosan.

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

    International Nuclear Information System (INIS)

    Nguyen Duy Lam; Tran Bang Diep; Tran Minh Quynh; Le Thi Dinh; Nguyen Van Binh; Ho Minh Duc; Vo Van Thuan

    2003-01-01

    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)

  8. Poly(D,L-Lactide-Co-Glycolide) Tubes With Multifilament Chitosan Yarn or Chitosan Sponge Core in Nerve Regeneration.

    Science.gov (United States)

    Wlaszczuk, Adam; Marcol, Wiesław; Kucharska, Magdalena; Wawro, Dariusz; Palen, Piotr; Lewin-Kowalik, Joanna

    2016-11-01

    The influence of different kinds of nerve guidance conduits on regeneration of totally transected rat sciatic nerves through a 7-mm gap was examined. Five different types of conduits made of chitosan and poly(D,L-lactide-co-glycolide) (PLGA) were constructed and tested in vivo. We divided 50 animals into equal groups of 10, with a different type of conduit implanted in each group: chitosan sponge core with an average molecular mass of polymer (Mv) of 287 kDa with 7 channels in a PLGA sleeve, chitosan sponge core with an Mv of 423 kDa with 7 channels in a PLGA sleeve, chitosan sponge core (Mv, 423 kDa) with 13 channels in a PLGA sleeve, chitosan multifilament yarn in a PLGA sleeve, and a PLGA sleeve only. Seven weeks after the operation, we examined the distance covered by regenerating nerve fibers, growing of nerves into the conduit's core, and intensity and type of inflammatory reaction in the conduit, as well as autotomy behavior (reflecting neuropathic pain intensity) in the animals. Two types of conduits were allowing nerve outgrowth through the gap with minor autotomy and minor inflammatory reactions. These were the conduits with chitosan multifilament yarn in a PLGA sleeve and the conduits with 13-channel microcrystalline chitosan sponge in a PLGA sleeve. The type of chitosan used to build the nerve guidance conduit influences the intensity and character of inflammatory reaction present during nerve regeneration, which in turn affects the distance crossed by regenerating nerve fibers, growing of the nerve fibers into the conduit's core, and the intensity of autotomy in the animals. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  9. Mechanical property, degradation rate, and bone cell growth of chitosan coated titanium influenced by degree of deacetylation of chitosan.

    Science.gov (United States)

    Yuan, Youling; Chesnutt, Betsy M; Wright, Lee; Haggard, Warren O; Bumgardner, Joel D

    2008-07-01

    Chitosan has shown promise as a coating for dental/craniofacial and orthopaedic implants. However, the effects of degree of deacetylation (DDA) of chitosan on coating bond strength, degradation, and biological performance is not known. The aim of this project was to evaluate bonding, degradation, and bone cell growth on titanium coated with chitosans of different DDA and from different manufacturers. Three different chitosans, 80.6%, 81.7%, and 92.3% DDA were covalently bonded to titanium coupons via silane-glutaraldehyde molecules. Bond strengths were evaluated in mechanical tensile tests, and degradation, over 5 weeks, was conducted in cell culture medium with and without 100 microg/mL lysozyme. Cytocompatibility was evaluated for 10 days using UMR 106 osteoblastic cells. Results showed that mean chitosan coating bond strengths ranged from 2.2-3.8 MPa, and that there was minimal affect of DDA on coating bond strengths. The coatings exhibited little dissolution over 5 weeks in medium with or without lysozyme. However, the molecular weight (MW) of the chitosan coatings remaining on the titanium samples after 5 weeks decreased by 69-85% with the higher DDA chitosan coatings exhibiting less percent change in MW than the lower DDA materials. The growth of the UMR 106 osteoblast cells on the 81.7% DDA chitosan coating was lower on days 3 and 5, as compared with the other two coatings, but by day 10, there were no differences in growth among three coatings or to the uncoated titanium controls. Differences in growth were attributed to differences in manufacturer source material, though all coatings were judged to be osteocompatible in vitro. 2007 Wiley Periodicals, Inc.

  10. Guided bone regeneration with asymmetric collagen-chitosan membranes containing aspirin-loaded chitosan nanoparticles

    Directory of Open Access Journals (Sweden)

    Zhang J

    2017-12-01

    Full Text Available Jiayu Zhang,1 Shiqing Ma,1 Zihao Liu,1 Hongjuan Geng,1 Xin Lu,1 Xi Zhang,1 Hongjie Li,1 Chenyuan Gao,2 Xu Zhang,1 Ping Gao1 1School of Dentistry, Hospital of Stomatology, Tianjin Medical University, Tianjin, 2Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing, People’s Republic of China Introduction: Membranes allowing the sustained release of drugs that can achieve cell adhesion are very promising for guided bone regeneration. Previous studies have suggested that aspirin has the potential to promote bone regeneration. The purpose of this study was to prepare a local drug delivery system with aspirin-loaded chitosan nanoparticles (ACS contained in an asymmetric collagen-chitosan membrane (CCM. Methods: In this study, the ACS were fabricated using different concentrations of aspirin (5 mg, 25 mg, 50 mg, and 75 mg. The drug release behavior of ACS was studied. Transmission electron microscopy (TEM and scanning electron microscopy (SEM were used to examine the micromorphology of ACS and aspirin-loaded chitosan nanoparticles contained in chitosan-collagen membranes (ACS-CCM. In vitro bone mesenchymal stem cells (BMSCs were cultured and critical-sized cranial defects on Sprague-Dawley rats were made to evaluate the effect of the ACS-CCM on bone regeneration.Results: Drug release behavior results of ACS showed that the nanoparticles fabricated in this study could successfully sustain the release of the drug. TEM showed the morphology of the nanoparticles. SEM images indicated that the asymmetric membrane comprised a loose collagen layer and a dense chitosan layer. In vitro studies showed that ACS-CCM could promote the proliferation of BMSCs, and that the degree of differentiated BMSCs seeded on CCMs containing 50 mg of ACS was higher than that of other membranes. Micro-computed tomography showed that 50 mg of ACS-CCM resulted in enhanced bone regeneration compared with the control group.Conclusion: This

  11. Removal of Arsenic (V) from Aqueous Solutions Using Chitosan-Red Scoria and Chitosan-Pumice Blends.

    Science.gov (United States)

    Asere, Tsegaye Girma; Mincke, Stein; De Clercq, Jeriffa; Verbeken, Kim; Tessema, Dejene A; Fufa, Fekadu; Stevens, Christian V; Du Laing, Gijs

    2017-08-09

    In different regions across the globe, elevated arsenic contents in the groundwater constitute a major health problem. In this work, a biopolymer chitosan has been blended with volcanic rocks (red scoria and pumice) for arsenic (V) removal. The effect of three blending ratios of chitosan and volcanic rocks (1:2, 1:5 and 1:10) on arsenic removal has been studied. The optimal blending ratio was 1:5 (chitosan: volcanic rocks) with maximum adsorption capacity of 0.72 mg/g and 0.71 mg/g for chitosan: red scoria (Ch-Rs) and chitosan: pumice (Ch-Pu), respectively. The experimental adsorption data fitted well a Langmuir isotherm ( R ² > 0.99) and followed pseudo-second-order kinetics. The high stability of the materials and their high arsenic (V) removal efficiency (~93%) in a wide pH range (4 to 10) are useful for real field applications. Moreover, the blends could be regenerated using 0.05 M NaOH and used for several cycles without losing their original arsenic removal efficiency. The results of the study demonstrate that chitosan-volcanic rock blends should be further explored as a potential sustainable solution for removal of arsenic (V) from water.

  12. Impact of salt form and molecular weight of chitosan on swelling and drug release from chitosan matrix tablets.

    Science.gov (United States)

    Huanbutta, Kampanart; Cheewatanakornkool, Kamonrak; Terada, Katsuhide; Nunthanid, Jurairat; Sriamornsak, Pornsak

    2013-08-14

    Magnetic resonance imaging (MRI) and gravimetric techniques were used to assess swelling and erosion behaviors of hydrophilic matrix tablets made of chitosan. The impact of salt form, molecular weight (MW) and dissolution medium on swelling behavior and drug (theophylline) release was studied. The matrix tablets made of chitosan glycolate (CGY) showed the greatest swelling in both acid and neutral media, compared to chitosan aspartate, chitosan glutamate and chitosan lactate. MRI illustrated that swelling region of CGY in both media was not different in the first 100 min but glassy region (dry core) in 0.1N HCl was less than in pH 6.8 buffer. The tablets prepared from chitosan with high MW swelled greater than those of low MW. Moreover, CGY can delay drug release in the acid condition due to thick swollen gel and low erosion rate. Therefore, CGY may be suitably applied as sustained drug release polymer or enteric coating material. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Effect of enzymatic degradation of chitosan in polyhydroxybutyrate/chitosan/calcium phosphate composites on in vitro osteoblast response.

    Science.gov (United States)

    Giretova, Maria; Medvecky, Lubomir; Stulajterova, Radoslava; Sopcak, Tibor; Briancin, Jaroslav; Tatarkova, Monika

    2016-12-01

    Polyhydroxybutyrate/chitosan/calcium phosphate composites are interesting biomaterials for utilization in regenerative medicine and they may by applied in reconstruction of deeper subchondral defects. Insufficient informations were found in recent papers about the influence of lysozyme degradation of chitosan in calcium phosphate/chitosan based composites on in vitro cytotoxicity and proliferation activity of osteoblasts. The effect of enzymatic chitosan degradation on osteoblasts proliferation was studied on composite films in which the porosity of origin 3D scaffolds was eliminated and the surface texture was modified. The significantly enhanced proliferation activity with faster population growth of osteoblasts were found on enzymatically degraded biopolymer composite films with α-tricalcium phosphate and nanohydroxyapatite. No cytotoxicity of composite films prepared from lysozyme degraded scaffolds containing a large fraction of low molecular weight chitosans (LMWC), was revealed after 10 days of cultivation. Contrary to above in the higher cytotoxicity origin untreated nanohydroxyapatite films and porous composite scaffolds. The results showed that the synergistic effect of surface distribution, morphology of nanohydroxyapatite particles, microtopography and the presence of LMWC due to chitosan degradation in composite films were responsible for compensation of the cytotoxicity of nanohydroxyapatite composite films or porous composite scaffolds.

  14. Fabrication, characterization and in vitro drug release behavior of electrospun PLGA/chitosan nanofibrous scaffold

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Z.X.; Zheng, W.; Li, L. [Center for Biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China); Zheng, Y.F., E-mail: yfzheng@pku.edu.cn [Center for Biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China); Department of Advanced Materials and Nanotechnology, College of Engineering, Peking University, Beijing 100871 (China)

    2011-02-15

    Graphical abstract: The fenbufen loaded PLGA/chitosan nanofibrous scaffolds were fabricated by electrospinning. The hydrophilicity of nanofibrous scaffold was enhanced with the increase of chitosan content. The drug release also is accelerated with chitosan increasing because the higher hydrophilicity makes drug diffusing from scaffold more easily. Research highlights: {yields} The average diameter increased with the increase of chitosan content and then decreased. {yields} The release rate of fenbufen increased with the increase of chitosan. {yields} The aligned nanofibrous scaffold exhibits lower drug release rate. {yields} The drug release could be controlled by crosslinking in glutaraldehyde vapor. - Abstract: In this study both aligned and randomly oriented poly(D,L-lactide-co-glycolide) (PLGA)/chitosan nanofibrous scaffold have been prepared by electrospinning. The ratio of PLGA to chitosan was adjusted to get smooth nanofiber surface. Morphological characterization using scanning electron microscopy showed that the aligned nanofiber diameter distribution obtained by electrospinning of polymer blend increased with the increase of chitosan content which was similar to that of randomly oriented nanofibers. The release characteristic of model drug fenbufen (FBF) from the FBF-loaded aligned and randomly oriented PLGA and PLGA/chitosan nanofibrous scaffolds was investigated. The drug release rate increased with the increase of chitosan content because the addition of chitosan enhanced the hydrophilicity of the PLGA/chitosan composite scaffold. Moreover, for the aligned PLGA/chitosan nanofibrous scaffold the release rate was lower than that of randomly oriented PLGA/chitosan nanofibrous scaffold, which indicated that the nanofiber arrangement would influence the release behavior. In addition, crosslinking in glutaraldehyde vapor would decrease the burst release of FBF from FBF-loaded PLGA/chitosan nanofibrous scaffold with a PLGA/chitosan ratio less than 9/1, which

  15. Fabrication, characterization and in vitro drug release behavior of electrospun PLGA/chitosan nanofibrous scaffold

    International Nuclear Information System (INIS)

    Meng, Z.X.; Zheng, W.; Li, L.; Zheng, Y.F.

    2011-01-01

    Graphical abstract: The fenbufen loaded PLGA/chitosan nanofibrous scaffolds were fabricated by electrospinning. The hydrophilicity of nanofibrous scaffold was enhanced with the increase of chitosan content. The drug release also is accelerated with chitosan increasing because the higher hydrophilicity makes drug diffusing from scaffold more easily. Research highlights: → The average diameter increased with the increase of chitosan content and then decreased. → The release rate of fenbufen increased with the increase of chitosan. → The aligned nanofibrous scaffold exhibits lower drug release rate. → The drug release could be controlled by crosslinking in glutaraldehyde vapor. - Abstract: In this study both aligned and randomly oriented poly(D,L-lactide-co-glycolide) (PLGA)/chitosan nanofibrous scaffold have been prepared by electrospinning. The ratio of PLGA to chitosan was adjusted to get smooth nanofiber surface. Morphological characterization using scanning electron microscopy showed that the aligned nanofiber diameter distribution obtained by electrospinning of polymer blend increased with the increase of chitosan content which was similar to that of randomly oriented nanofibers. The release characteristic of model drug fenbufen (FBF) from the FBF-loaded aligned and randomly oriented PLGA and PLGA/chitosan nanofibrous scaffolds was investigated. The drug release rate increased with the increase of chitosan content because the addition of chitosan enhanced the hydrophilicity of the PLGA/chitosan composite scaffold. Moreover, for the aligned PLGA/chitosan nanofibrous scaffold the release rate was lower than that of randomly oriented PLGA/chitosan nanofibrous scaffold, which indicated that the nanofiber arrangement would influence the release behavior. In addition, crosslinking in glutaraldehyde vapor would decrease the burst release of FBF from FBF-loaded PLGA/chitosan nanofibrous scaffold with a PLGA/chitosan ratio less than 9/1, which would be beneficial

  16. Effects of Spray Drying on Physicochemical Properties of Chitosan Acid Salts

    OpenAIRE

    Cervera, Mirna Fernández; Heinämäki, Jyrki; de la Paz, Nilia; López, Orestes; Maunu, Sirkka Liisa; Virtanen, Tommi; Hatanpää, Timo; Antikainen, Osmo; Nogueira, Antonio; Fundora, Jorge; Yliruusi, Jouko

    2011-01-01

    The effects of spray-drying process and acidic solvent system on physicochemical properties of chitosan salts were investigated. Chitosan used in spray dryings was obtained by deacetylation of chitin from lobster (Panulirus argus) origin. The chitosan acid salts were prepared in a laboratory-scale spray drier, and organic acetic acid, lactic acid, and citric acid were used as solvents in the process. The physicochemical properties of chitosan salts were investigated by means of solid-state CP...

  17. 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...

  18. Beta dosimetry in intraperitoneal administration of 166Ho-chitosan complex

    International Nuclear Information System (INIS)

    Kim, E. H.; Lim, S. M.; Park, K. B.

    1998-01-01

    Intraperitoneal administration of radioisotopes is suggested to treat the metastatic ovarian cancer in the peritoneal cavity. Administering beta-emitting radioisotopes into the peritoneal cavity allows the maximum energy delivery to the cancerous cells of the peritoneal wall surface while sparing the normal cells located in deep site of the peritoneal wall. In this study, dose estimates of the peritoneal wall are provided to be used for prescribing the amount of 166 Ho-chitosan complex administered. The 166 Ho-chitosan complex diffused in the peritoneal fluid may attach to the peritoneal wall surface. The attachment fraction of 166 Ho-chitosan complex to the peritoneal wall surface is obtained by simulating the ascites with Fischer rats. Both volume source in the peritoneal fluid and the surface source over the peritoneal wall surface are counted for the contribution to the peritoneal wall dose. The Monte Carlo code EGS4 is used to simulate the energy transfer of the beta particles emitted from 166 Ho. A plane geometrical model of semi-infinite volume describes the peritoneal cavity and the peritoneal wall. A semi-infinite plane of 10 μm in thickness at every 1 mm of depth in the peritoneal wall is taken as the target in dose estimation. Greater than 98 percents of attachment fraction has been observed from the experiments with Fischer rats. Given 1.3 μCi/cm 2 and 2.4 μCi/ml of uniform activity density, absorbed dose is 123 Gy, 8.59 Gy, 3.00 Gy, 1.03 Gy, and 327 Gy at 0 mm, 1 mm, 2 mm, 3 mm, and 4 mm in depth to the peritoneal wall, respectively

  19. Molecular nuclear imaging for targeting and trafficking

    International Nuclear Information System (INIS)

    Bom, Hee Seung; Min, Jung Jun; Jeong, Hwan-Jeong

    2006-01-01

    Noninvasive molecular targeting in living subjects is highly demanded for better understanding of such diverse topics as the efficient delivery of drugs, genes, or radionuclides for the diagnosis or treatment of diseases. Progress in molecular biology, genetic engineering and polymer chemistry provides various tools to target molecules and cells in vivo. We used chitosan as a polymer, and 99m Tc as a radionuclide. We developed 99m Tc-galactosylated chitosan to target asialoglycoprotein receptors for nuclear imaging. We also developed 99m Tc-HYNIC-chitosan-transferrin to target inflammatory cells, which was more effective than 67 Ga-citrate for imaging inflammatory lesions. For an effective delivery of molecules, a longer circulation time is needed. We found that around 10% PEGylation was most effective to prolong the circulation time of liposomes for nuclear imaging of 99m Tc-HMPAO-labeled liposomes in rats. Using various characteristics of molecules, we can deliver drugs into targets more effectively. We found that 99m Tc-labeled biodegradable pullulan-derivatives are retained in tumor tissue in response to extracellular ion-strength. For the trafficking of various cells or bacteria in an intact animal, we used optical imaging techniques or radiolabeled cells. We monitored tumor-targeting bacteria by bioluminescent imaging techniques, dentritic cells by radiolabeling and neuronal stem cells by sodium-iodide symporter reporter gene imaging. In summary, we introduced recent achievements of molecular nuclear imaging technologies in targeting receptors for hepatocyte or inflammatory cells and in trafficking bacterial, immune and stem cells using molecular nuclear imaging techniques

  20. Halloysite and chitosan oligosaccharide nanocomposite for wound healing.

    Science.gov (United States)

    Sandri, Giuseppina; Aguzzi, Carola; Rossi, Silvia; Bonferoni, Maria Cristina; Bruni, Giovanna; Boselli, Cinzia; Cornaglia, Antonia Icaro; Riva, Federica; Viseras, Cesar; Caramella, Carla; Ferrari, Franca

    2017-07-15

    Halloysite is a natural nanotubular clay mineral (HNTs, Halloysite Nano Tubes) chemically identical to kaolinite and, due to its good biocompatibility, is an attractive nanomaterial for a vast range of biological applications. Chitosan oligosaccharides are homo- or heterooligomers of N-acetylglucosamine and D-glucosamine, that accelerate wound healing by enhancing the functions of inflammatory and repairing cells. The aim of the work was the development of a nanocomposite based on HNTs and chitosan oligosaccharides, to be used as pour powder to enhance healing in the treatment of chronic wounds. A 1:0.05 wt ratio HTNs/chitosan oligosaccharide nanocomposite was obtained by simply stirring the HTNs powder in a 1% w/w aqueous chitosan oligosaccharide solution and was formed by spontaneous ionic interaction resulting in 98.6% w/w HTNs and 1.4% w/w chitosan oligosaccharide composition. Advanced electron microscopy techniques were considered to confirm the structure of the hybrid nanotubes. Both HTNs and HTNs/chitosan oligosaccharide nanocomposite showed good in vitro biocompatibility with normal human dermal fibroblasts up to 300μg/ml concentration and enhanced in vitro fibroblast motility, promoting both proliferation and migration. The HTNs/chitosan oligosaccharide nanocomposite and the two components separately were tested for healing capacity in a murine (rat) model. HTNs/chitosan oligosaccharide allowed better skin reepithelization and reorganization than HNTs or chitosan oligosaccharide separately. The results suggest to develop the nanocomposite as a medical device for wound healing. The present work is focused on the development of halloysite and chitosan oligosaccharide nanocomposite for wound healing. It considers a therapeutic option for difficult to heal skin lesions and burns. The significance of the research considers two fundamental aspects: the first one is related to the development of a self-assembled nanocomposite, formed by spontaneous ionic

  1. Chitosan based nanofibers in bone tissue engineering.

    Science.gov (United States)

    Balagangadharan, K; Dhivya, S; Selvamurugan, N

    2017-11-01

    Bone tissue engineering involves biomaterials, cells and regulatory factors to make biosynthetic bone grafts with efficient mineralization for regeneration of fractured or damaged bones. Out of all the techniques available for scaffold preparation, electrospinning is given priority as it can fabricate nanostructures. Also, electrospun nanofibers possess unique properties such as the high surface area to volume ratio, porosity, stability, permeability and morphological similarity to that of extra cellular matrix. Chitosan (CS) has a significant edge over other materials and as a graft material, CS can be used alone or in combination with other materials in the form of nanofibers to provide the structural and biochemical cues for acceleration of bone regeneration. Hence, this review was aimed to provide a detailed study available on CS and its composites prepared as nanofibers, and their associated properties found suitable for bone tissue engineering. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Effect of chitosan on resist printing of cotton fabrics with reactive dyes

    African Journals Online (AJOL)

    The concentration of chitosan, types of resist agent, curing temperature and curing time were varied to determine their effects on resist-printed cotton fabrics. An optimal chitosan concentration of 1.6% resulted in the greatest resist effect on printed cotton fabrics. For mixtures, a 6:4 ratio of citric acid : chitosan and an 8:2 ...

  3. Effect of chitosan and its derivatives as antifungal and preservative agents on postharvest green asparagus.

    Science.gov (United States)

    Qiu, Miao; Wu, Chu; Ren, Gerui; Liang, Xinle; Wang, Xiangyang; Huang, Jianying

    2014-07-15

    The antifungal activity and effect of high-molecular weight chitosan (H-chitosan), low-molecular weight chitosan (L-chitosan) and carboxymethyl chitosan (C-chitosan) coatings on postharvest green asparagus were evaluated. L-chitosan and H-chitosan efficiently inhibited the radial growth of Fusarium concentricum separated from postharvest green asparagus at 4 mg/ml, which appeared to be more effective in inhibiting spore germination and germ tube elongation than that of C-chitosan. Notably, spore germination was totally inhibited by L-chitosan and H-chitosan at 0.05 mg/ml. Coated asparagus did not show any apparent sign of phytotoxicity and maintained good quality over 28 days of cold storage, according to the weight loss and general quality aspects. Present results inferred that chitosan could act as an attractive preservative agent for postharvest green asparagus owing to its antifungal activity and its ability to stimulate some defense responses during storage. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Chitosan-Based Nano-Embedded Microparticles: Impact of Nanogel Composition on Physicochemical Properties

    DEFF Research Database (Denmark)

    Islam, Paromita; Water, Jorrit Jeroen; Bohr, Adam

    2016-01-01

    Chitosan-based nanogels have been widely applied as drug delivery vehicles. Spray-drying of said nanogels allows for the preparation of dry powder nano-embedded microparticles. In this work, chitosan-based nanogels composed of chitosan, alginate, and/or sodium tri-penta phosphate were investigated...

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    Graphical abstract: The type of the functional groups can be used to modulating interactions between graphene sheet and chitosan. - Highlights: • Investigate interfacial interactions between chitosan and functionalized graphene by DFT. • Observe covalent linkages between COOH-modified graphene and chitosan units. • Multi-functionalized graphene regulates the interfacial interactions with chitosan. • It is useful for guiding the preparation of graphene/chitosan composites. - Abstract: 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 (NH 2 -), 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.

  6. The effect of chitosan molecular weight on the properties of alginate ...

    African Journals Online (AJOL)

    Purpose: The aim of the present study was to investigate the effect of chitosan molecular weight on size, size distribution, release rate, mucoadhesive properties and electrostatic bonding of alginate/chitosan microparticles containing prednisolone. Methods: Three mucoadhesive alginate/chitosan microparticle formulations, ...

  7. Preparation and characterization of biocomposite film based on chitosan and kombucha tea as active food packaging

    DEFF Research Database (Denmark)

    Ashrafi, Azam; Jokar, Maryam

    2018-01-01

    An active film composed of chitosan and kombucha tea (KT) was successfully prepared using the solvent casting technique. The effect of incorporation of KT at the levels 1%–3% w/w on the physical and functional properties of chitosan film was investigated. The antimicrobial activity of chitosan...

  8. Preparation and Characterization of Chitosan-coated Fe3O4 Nanoparticles using Ex-Situ Co-Precipitation Method and Tripolyphosphate/Sulphate as Dual Crosslinkers

    Science.gov (United States)

    Wulandari, Ika O.; Mardila, Vita T.; Santjojo, D. J. Djoko H.; Sabarudin, Akhmad

    2018-01-01

    The unique properties of nanomaterial provide great opportunities to develop in several fields. Several types of nanoparticles have been proven beneficial for biomedical and therapeutic agent development. Particularly for clinical use, nanoparticles must be biocompatible and non-toxic. Iron oxide nanoparticles consist of either magnetite (Fe3O4) or maghemite (γ-Fe2O3) was eligible to use for in vivo application including targeting drug delivery. Due to their distinct properties, these nanoparticles could be directed to the specific target under external magnetic field. However, nanoparticles have a tendency to form agglomeration. Therefore, surface modification was required to reduce the agglomeration. In this study, nanoparticles of Fe3O4 were produced and coated by biomaterial (chitosan) using ex-situ co-precipitation method. Nanoparticles of Fe3O4 were synthesized by adding ammonia water into iron ferric and ferrous solution. Synthesis process of Fe3O4 was conducted prior to adding chitosan. Chitosan was then cross-linked by a combination of tripolyphosphate/sulphate. The different composition ratio and crosslinking time provide the different physical and magnetic characteristics of nanoparticles. Particle and crystallite size was determined by using Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) respectively, whereas magnetic characteristic was determined by Electron Spin Resonance (ESR). The results showed that the ratio enhancement between chitosan: Fe3O4 increase the particle size, while decreased the crystallite size. Morphology and particle size were influenced by the ratio of crosslinkers. It was found that the higher tripolyphosphate content was contributed to the small size and more spherical morphology. In addition, the influence of crosslinking time toward crystallite size was determined by altering stirring time. The longer duration of crosslinking time, provide the larger crystallite size of chitosan-Fe3O4. There was an interesting

  9. About the Sterilization of Chitosan Hydrogel Nanoparticles.

    Science.gov (United States)

    Galante, Raquel; Rediguieri, Carolina F; Kikuchi, Irene Satiko; Vasquez, Pablo A S; Colaço, Rogério; Serro, Ana Paula; Pinto, Terezinha J A

    2016-01-01

    In the last years, nanostructured biomaterials have raised a great interest as platforms for delivery of drugs, genes, imaging agents and for tissue engineering applications. In particular, hydrogel nanoparticles (HNP) associate the distinctive features of hydrogels (high water uptake capacity, biocompatibility) with the advantages of being possible to tailor its physicochemical properties at nano-scale to increase solubility, immunocompatibility and cellular uptake. In order to be safe, HNP for biomedical applications, such as injectable or ophthalmic formulations, must be sterile. Literature is very scarce with respect to sterilization effects on nanostructured systems, and even more in what concerns HNP. This work aims to evaluate the effect and effectiveness of different sterilization methods on chitosan (CS) hydrogel nanoparticles. In addition to conventional methods (steam autoclave and gamma irradiation), a recent ozone-based method of sterilization was also tested. A model chitosan-tripolyphosphate (TPP) hydrogel nanoparticles (CS-HNP), with a broad spectrum of possible applications was produced and sterilized in the absence and in the presence of protective sugars (glucose and mannitol). Properties like size, zeta potential, absorbance, morphology, chemical structure and cytotoxicity were evaluated. It was found that the CS-HNP degrade by autoclaving and that sugars have no protective effect. Concerning gamma irradiation, the formation of agglomerates was observed, compromising the suspension stability. However, the nanoparticles resistance increases considerably in the presence of the sugars. Ozone sterilization did not lead to significant physical adverse effects, however, slight toxicity signs were observed, contrarily to gamma irradiation where no detectable changes on cells were found. Ozonation in the presence of sugars avoided cytotoxicity. Nevertheless, some chemical alterations were observed in the nanoparticles.

  10. About the Sterilization of Chitosan Hydrogel Nanoparticles.

    Directory of Open Access Journals (Sweden)

    Raquel Galante

    Full Text Available In the last years, nanostructured biomaterials have raised a great interest as platforms for delivery of drugs, genes, imaging agents and for tissue engineering applications. In particular, hydrogel nanoparticles (HNP associate the distinctive features of hydrogels (high water uptake capacity, biocompatibility with the advantages of being possible to tailor its physicochemical properties at nano-scale to increase solubility, immunocompatibility and cellular uptake. In order to be safe, HNP for biomedical applications, such as injectable or ophthalmic formulations, must be sterile. Literature is very scarce with respect to sterilization effects on nanostructured systems, and even more in what concerns HNP. This work aims to evaluate the effect and effectiveness of different sterilization methods on chitosan (CS hydrogel nanoparticles. In addition to conventional methods (steam autoclave and gamma irradiation, a recent ozone-based method of sterilization was also tested. A model chitosan-tripolyphosphate (TPP hydrogel nanoparticles (CS-HNP, with a broad spectrum of possible applications was produced and sterilized in the absence and in the presence of protective sugars (glucose and mannitol. Properties like size, zeta potential, absorbance, morphology, chemical structure and cytotoxicity were evaluated. It was found that the CS-HNP degrade by autoclaving and that sugars have no protective effect. Concerning gamma irradiation, the formation of agglomerates was observed, compromising the suspension stability. However, the nanoparticles resistance increases considerably in the presence of the sugars. Ozone sterilization did not lead to significant physical adverse effects, however, slight toxicity signs were observed, contrarily to gamma irradiation where no detectable changes on cells were found. Ozonation in the presence of sugars avoided cytotoxicity. Nevertheless, some chemical alterations were observed in the nanoparticles.

  11. Zinc-Modified Nanotransporter of Doxorubicin for Targeted Prostate Cancer Delivery

    Directory of Open Access Journals (Sweden)

    Sylvie Skalickova

    2017-12-01

    Full Text Available This work investigated the preparation of chitosan nanoparticles used as carriers for doxorubicin for targeted cancer delivery. Prepared nanocarriers were stabilized and functionalized via zinc ions incorporated into the chitosan nanoparticle backbone. We took the advantage of high expression of sarcosine in the prostate cancer cells. The prostate cancer targeting was mediated by the AntiSar antibodies decorated surface of the nanocage. Formation of the chitosan nanoparticles was determined using a ninhydrin assay and differential pulse voltammetry. Obtained results showed the strong effect of tripolyphosphine on the nanoparticle formation. The zinc ions affected strong chitosan backbone coiling both in inner and outer chitosan nanoparticle structure. Zinc electrochemical signal depended on the level of the complex formation and the potential shift from −960 to −950 mV. Formed complex is suitable for doxorubicin delivery. It was observed the 20% entrapment efficiency of doxorubicin and strong dependence of drug release after 120 min in the blood environment. The functionality of the designed nanotransporter was proven. The purposed determination showed linear dependence in the concentration range of Anti-sarcosine IgG labeled gold nanoparticles from 0 to 1000 µg/mL and the regression equation was found to be y = 3.8x − 66.7 and R2 = 0.99. Performed ELISA confirmed the ability of Anti-sarcosine IgG labeled chitosan nanoparticles with loaded doxorubicin to bind to the sarcosine molecule. Observed hemolytic activity of the nanotransporter was 40%. Inhibition activity of our proposed nanotransporter was evaluated to be 0% on the experimental model of S. cerevisiae. Anti-sarcosine IgG labeled chitosan nanoparticles, with loaded doxorubicin stabilized by Zn ions, are a perspective type of nanocarrier for targeted drug therapy managed by specific interaction with sarcosine and metallothionein for prostate cancer.

  12. Design of a potentially prebiotic and responsive encapsulation material for probiotic bacteria based on chitosan and sulfated β-glucan.

    Science.gov (United States)

    Yucel Falco, Cigdem; Sotres, Javier; Rascón, Ana; Risbo, Jens; Cárdenas, Marité

    2017-02-01

    Chitosan and sulfated oat β-glucan are materials suitable to create a prebiotic coating for targeted delivery to gastrointestinal system, using the layer by layer technology. Quartz crystal microbalance with dissipation (QCM-D), spectroscopic ellipsometry (SE) and atomic force microscopy (AFM) were used to assess the multilayer formation capacity and characterize the resulting coatings in terms of morphology and material properties such as structure and rigidity. The coating of colloidal materials was proven, specifically on L. acidophilus bacteria as measured by changes in the bacterial suspension zeta potential. Viability of coated cells was shown using plate counting method. The coatings on solid surfaces were examined after exposure to mimics of gastrointestinal fluids and a commercially available β-glucanase. Successful build-up of multilayers was confirmed with QCM-D and SE. Zeta potential values proved the coating of cells. There was 2 log CFU/mL decrease after coating cells with four alternating layers of chitosan and sulfated β-glucan when compared to viability of uncoated cells. The coatings were partially degraded after exposure to simulated intestinal fluid and restructured as a result of β-glucanase treatment, mimicking enzymes present in the microflora of the human gut, but seemed to resist acidic gastric conditions. Therefore, coatings of chitosan and sulfated β-glucan can potentially be exploited as carriers for probiotics and delicate nutraceuticals. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Chitosan for gene delivery and orthopedic tissue engineering applications.

    Science.gov (United States)

    Raftery, Rosanne; O'Brien, Fergal J; Cryan, Sally-Ann

    2013-05-15

    Gene therapy involves the introduction of foreign genetic material into cells in order exert a therapeutic effect. The application of gene therapy to the field of orthopaedic tissue engineering is extremely promising as the controlled release of therapeutic proteins such as bone morphogenetic proteins have been shown to stimulate bone repair. However, there are a number of drawbacks associated with viral and synthetic non-viral gene delivery approaches. One natural polymer which has generated interest as a gene delivery vector is chitosan. Chitosan is biodegradable, biocompatible and non-toxic. Much of the appeal of chitosan is due to the presence of primary amine groups in its repeating units which become protonated in acidic conditions. This property makes it a promising candidate for non-viral gene delivery. Chitosan-based vectors have been shown to transfect a number of cell types including human embryonic kidney cells (HEK293) and human cervical cancer cells (HeLa). Aside from its use in gene delivery, chitosan possesses a range of properties that show promise in tissue engineering applications; it is biodegradable, biocompatible, has anti-bacterial activity, and, its cationic nature allows for electrostatic interaction with glycosaminoglycans and other proteoglycans. It can be used to make nano- and microparticles, sponges, gels, membranes and porous scaffolds. Chitosan has also been shown to enhance mineral deposition during osteogenic differentiation of MSCs in vitro. The purpose of this review is to critically discuss the use of chitosan as a gene delivery vector with emphasis on its application in orthopedic tissue engineering.

  14. Chitosan nanoparticles as a modified diclofenac drug release system

    Science.gov (United States)

    Duarte Junior, Anivaldo Pereira; Tavares, Eraldo José Madureira; Alves, Taís Vanessa Gabbay; de Moura, Márcia Regina; da Costa, Carlos Emmerson Ferreira; Silva Júnior, José Otávio Carréra; Ribeiro Costa, Roseane Maria

    2017-08-01

    This study evaluated a modified nanostructured release system employing diclofenac as a drug model. Biodegradable chitosan nanoparticles were prepared with chitosan concentrations between 0.5 and 0.8% ( w/ v) by template polymerization method using methacrylic acid in aqueous solution. Chitosan-poly(methacrylic acid) (CS-PMAA) nanoparticles showed uniform size around 50-100 nm, homogeneous morphology, and spherical shape. Raw material and chitosan nanoparticles were characterized by thermal analysis, Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM), confirming the interaction between chitosan and methacrylic acid during nanoparticles preparation. Diclofenac sorption on the chitosan nanoparticles surface was achieved by incubation in water/ethanol (1:1) drug solution in concentrations of 0.5 and 0.8 mg/mL. The diclofenac amount sorbed per gram of CS-PMAA nanoparticles, when in a 0.5 mg/mL sodium diclofenac solution, was as follows: 12.93, 15, 20.87, and 29.63 mg/g for CS-PMAA nanoparticles 0.5, 0.6, 0.7, and 0.8% ( w/ v), respectively. When a 0.8 mg/mL sodium diclofenac solution was used, higher sorption efficiencies were obtained: For CS-PMAA nanoparticles with chitosan concentrations of 0.5, 0.6, 0.7, and 0.8% ( w/ v), the sorption efficiencies were 33.39, 49.58, 55.23, and 67.2 mg/g, respectively. Diclofenac sorption kinetics followed a second-order kinetics. Drug release from nanoparticles occurred in a period of up to 48 h and obeyed Korsmeyer-Peppas model, which was characterized mainly by Fickian diffusion transport. [Figure not available: see fulltext.

  15. Synthesis and characterization of magnetite/PLGA/chitosan nanoparticles

    Science.gov (United States)

    Ibarra, Jaime; Melendres, Julio; Almada, Mario; Burboa, María G.; Taboada, Pablo; Juárez, Josué; Valdez, Miguel A.

    2015-09-01

    In this work, we report the synthesis and characterization of a new hybrid nanoparticles system performed by magnetite nanoparticles, loaded in a PLGA matrix, and stabilized by different concentrations of chitosan. Magnetite nanoparticles were hydrophobized with oleic acid and entrapped in a PLGA matrix by the emulsion solvent evaporation method, after that, magnetite/PLGA/chitosan nanoparticles were obtained by adding dropwise magnetite/PLGA nanoparticles in chitosan solutions. Magnetite/PLGA nanoparticles produced with different molar ratios did not show significant differences in size and the 3:1 molar ratio showed best spherical shapes as well as uniform particle size. Isothermal titration calorimetry studies demonstrated that the first stage of PLGA-chitosan interaction is mostly regulated by electrostatic forces. Based on a single set of identical sites model, we obtained for the average number of binding sites a value of 3.4, which can be considered as the number of chitosan chains per nanoparticle. This value was confirmed by using a model based on the DLVO theory and fitting zeta potential measurements of magnetite/PLGA/chitosan nanoparticles. From the adjusted parameters, we found that an average number of chitosan molecules of 3.6 per nanoparticle are attached onto the surface of the PLGA matrix. Finally, we evaluated the effect of surface charge of nanoparticles on a membrane model of endothelial cells performed by a mixture of three phospholipids at the air-water interface. Different isotherms and adsorption curves show that cationic surface of charged nanoparticles strongly interact with the phospholipids mixture and these results can be the basis of future experiments to understand the nanoparticles- cell membrane interaction.

  16. Synthesis and characterization of magnetite/PLGA/chitosan nanoparticles

    International Nuclear Information System (INIS)

    Ibarra, Jaime; Melendres, Julio; Almada, Mario; Juárez, Josué; Valdez, Miguel A; Burboa, María G; Taboada, Pablo

    2015-01-01

    In this work, we report the synthesis and characterization of a new hybrid nanoparticles system performed by magnetite nanoparticles, loaded in a PLGA matrix, and stabilized by different concentrations of chitosan. Magnetite nanoparticles were hydrophobized with oleic acid and entrapped in a PLGA matrix by the emulsion solvent evaporation method, after that, magnetite/PLGA/chitosan nanoparticles were obtained by adding dropwise magnetite/PLGA nanoparticles in chitosan solutions. Magnetite/PLGA nanoparticles produced with different molar ratios did not show significant differences in size and the 3:1 molar ratio showed best spherical shapes as well as uniform particle size. Isothermal titration calorimetry studies demonstrated that the first stage of PLGA-chitosan interaction is mostly regulated by electrostatic forces. Based on a single set of identical sites model, we obtained for the average number of binding sites a value of 3.4, which can be considered as the number of chitosan chains per nanoparticle. This value was confirmed by using a model based on the DLVO theory and fitting zeta potential measurements of magnetite/PLGA/chitosan nanoparticles. From the adjusted parameters, we found that an average number of chitosan molecules of 3.6 per nanoparticle are attached onto the surface of the PLGA matrix. Finally, we evaluated the effect of surface charge of nanoparticles on a membrane model of endothelial cells performed by a mixture of three phospholipids at the air–water interface. Different isotherms and adsorption curves show that cationic surface of charged nanoparticles strongly interact with the phospholipids mixture and these results can be the basis of future experiments to understand the nanoparticles- cell membrane interaction. (paper)

  17. Emerging Biomedical Applications of Nano-Chitins and Nano-Chitosans Obtained via Advanced Eco-Friendly Technologies from Marine Resources

    Science.gov (United States)

    Muzzarelli, Riccardo A. A.; El Mehtedi, Mohamad; Mattioli-Belmonte, Monica

    2014-01-01

    The present review article is intended to direct attention to the technological advances made in the 2010–2014 quinquennium for the isolation and manufacture of nanofibrillar chitin and chitosan. Otherwise called nanocrystals or whiskers, n-chitin and n-chitosan are obtained either by mechanical chitin disassembly and fibrillation optionally assisted by sonication, or by e-spinning of solutions of polysaccharides often accompanied by poly(ethylene oxide) or poly(caprolactone). The biomedical areas where n-chitin may find applications include hemostasis and wound healing, regeneration of tissues such as joints and bones, cell culture, antimicrobial agents, and dermal protection. The biomedical applications of n-chitosan include epithelial tissue regeneration, bone and dental tissue regeneration, as well as protection against bacteria, fungi and viruses. It has been found that the nano size enhances the performances of chitins and chitosans in all cases considered, with no exceptions. Biotechnological approaches will boost the applications of the said safe, eco-friendly and benign nanomaterials not only in these fields, but also for biosensors and in targeted drug delivery areas. PMID:25415349

  18. Enhancement of Lactobacillus reuteri KUB-AC5 survival in broiler gastrointestinal tract by microencapsulation with alginate-chitosan semi-interpenetrating polymer networks.

    Science.gov (United States)

    Rodklongtan, A; La-ongkham, O; Nitisinprasert, S; Chitprasert, P

    2014-07-01

    To evaluate an alginate-chitosan microcapsule for an intestinal probiotic delivery system for broilers. Lactobacillus reuteri KUB-AC5 was successfully microencapsulated with alginate and chitosan mixtures using an emulsion cross-linking method with high microencapsulation efficiency. Scanning electron microscopy revealed a large number of the bacteria entrapped in the semi-interpenetrating network. The microcapsule effectively protected the cells against strong acids. The in vitro study showed that the 8 log CFU g(-1) was released at the jejunum and ileum. For the in vivo study, the number of probiotics was detected by a polymerase chain reaction-based random amplified polymorphic DNA technique. From provision of 10 log CFU, cell numbers of 5-8 log CFU were observed in the intestine. The alginate-chitosan microcapsule can serve as a potential intestine-targeted probiotic delivery system. To the best of our knowledge, this is the first comparison study of the in vitro and in vivo gastrointestinal profiles of microencapsulated probiotics used as feed additives for broilers. This study reveals the similarities and differences of the in vitro and in vivo probiotic profiles and provides convincing evidence of the potential use of the alginate-chitosan microcapsule as a probiotic delivery system. © 2014 The Society for Applied Microbiology.

  19. Chitosan Stabilized Gold-Folate-Poly(lactide-co-glycolide) Nanoplexes Facilitate Efficient Gene Delivery in Hepatic and Breast Cancer Cells.

    Science.gov (United States)

    Akinyelu, Jude; Singh, Moganavelli

    2018-07-01

    The biodegradable polymer, poly(lactide-co-glycolide) is a popular polymer of choice in many nanotherapeutic studies. Herein, we report on the synthesis and evaluation of four chitosan stabilized poly(lactide-co-glycolide) nanoparticles with and without coating with gold, and the targeting ligand, folic acid, as potential non-viral gene delivery vectors. The poly(lactide-co-glycolide) nanoparticles were synthesized via nanoprecipitation/solvent evaporation method in conjunction with the surface functionalizing folic acid and chitosan. The physiochemical properties (morphology, particle size, zeta potential, folic acid/chitosan presence, DNA binding), and biological properties (nuclease protection, in vitro cytotoxicity and transfection potential in human kidney, hepatocellular carcinoma and breast adenocarcinoma cells), of all four gene bound nanoparticles were evaluated. Gel retardation assays confirmed that all the nanoparticles were able to successfully bind the reporter plasmid, pCMV-luc DNA at varying weight ratios. The gold-folate-poly(lactide-co-glycolide) nanoplexes with the highest binding efficiency (w/w ratio 4:1), best protected the plasmid DNA as evidenced from the nuclease protection assays. Furthermore, these nanoplexes presented as spherical particles with an average particle size of 199.4 nm and zeta potential of 35.7 mV. Folic acid and chitosan functionalization of the nanoparticles was confirmed by attenuated total reflection-Fourier transform infrared spectroscopy. All nanoplexes maintained over 90% cell viability in all cell lines investigated. Interestingly, the gold-folate-poly(lactide-co-glycolide) nanoplexes showed a greater transgene activity in the hepatic and breast cancer cells compared to the other nanocomplexes in the same cell lines. The favorable size, colloidal stability, low cytotoxicity, significant transgene expression, and nuclease protection ability in vitro, all provide support for the use of gold

  20. Poly(ethylene glycol) and cyclodextrin-grafted chitosan: from methodologies to preparation and potential biotechnological applications

    Science.gov (United States)

    Campos, Estefânia V. R.; Oliveira, Jhones L.; Fraceto, Leonardo F.

    2017-11-01

    Chitosan, a polyaminosaccharide obtained by alkaline deacetylation of chitin, possesses useful properties including biodegradability, biocompatibility, low toxicity, and good miscibility with other polymers. It is extensively used in many applications in biology, medicine, agriculture, environmental protection, and the food and pharmaceutical industries. The amino and hydroxyl groups present in the chitosan backbone provide positions for modifications that are influenced by factors such as the molecular weight, viscosity, and type of chitosan, as well as the reaction conditions. The modification of chitosan by chemical methods is of interest because the basic chitosan skeleton is not modified and the process results in new or improved properties of the material. Among the chitosan derivatives, cyclodextrin-grafted chitosan and poly(ethylene glycol)-grafted chitosan are excellent candidates for a range of biomedical, environmental decontamination, and industrial purposes. This work discusses modifications including chitosan with attached cyclodextrin and poly(ethylene glycol), and the main applications of these chitosan derivatives in the biomedical field.

  1. Changes in blood aggregation with differences in molecular weight and degree of deacetylation of chitosan

    International Nuclear Information System (INIS)

    Hattori, Hidemi; Ishihara, Masayuki

    2015-01-01

    Because the molecular weight (Mw) and degree of deacetylation (DDA) of chitosan can vary depending on the purification method, the identification of appropriate chitosan structures is important for developing more effective hemostatic agents. In this study, the influence of varying Mw and DDA of chitosan on blood aggregation was characterized by 10 types of chitosan with different Mw and DDA, including oligomers. The highest aggregation of whole blood, washed erythrocytes and platelets in platelet-rich plasma (PRP) were observed in chitosan with Mw of 8.6 kDa or more and with DDA of 75 to 88%. However, chitosan with too high Mw (247 kDa) inhibited the aggregation of whole blood, washed erythrocytes and PRP at high chitosan concentration. At certain concentrations, chitosan with 75–85% DDA and 50–190 kDa and chitosan with 87.6% DDA and 247 kDa both aggregated proteins in PRP. Chitosan oligomer did not affect blood aggregation. The results suggested that the aggregation by chitosan depended on the interaction of positively charged chitosan with negatively charged erythrocytes, platelets and plasma protein. It seemed that a suitable balance of positive charge in chitosan and negative charge in hemocytes and some kinds of proteins was important. To develop a hemostatic with effective blood aggregation, the chitosan should not be limited to a single Mw and a single DDA but may be a mixed chitosan with wide range of Mw (8.6–247 kDa) and DDA of 75 to 88%. (paper)

  2. Identification of yeast genes that confer resistance to chitosan oligosaccharide (COS using chemogenomics

    Directory of Open Access Journals (Sweden)

    Jaime Maria DLA

    2012-06-01

    Full Text Available Abstract Background Chitosan oligosaccharide (COS, a deacetylated derivative of chitin, is an abundant, and renewable natural polymer. COS has higher antimicrobial properties than chitosan and is presumed to act by disrupting/permeabilizing the cell membranes of bacteria, yeast and fungi. COS is relatively non-toxic to mammals. By identifying the molecular and genetic targets of COS, we hope to gain a better understanding of the antifungal mode of action of COS. Results Three different chemogenomic fitness assays, haploinsufficiency (HIP, homozygous deletion (HOP, and multicopy suppression (MSP profiling were combined with a transcriptomic analysis to gain insight in to the mode of action and mechanisms of resistance to chitosan oligosaccharides. The fitness assays identified 39 yeast deletion strains sensitive to COS and 21 suppressors of COS sensitivity. The genes identified are involved in processes such as RNA biology (transcription, translation and regulatory mechanisms, membrane functions (e.g. signalling, transport and targeting, membrane structural components, cell division, and proteasome processes. The transcriptomes of control wild type and 5 suppressor strains overexpressing ARL1, BCK2, ERG24, MSG5, or RBA50, were analyzed in the presence and absence of COS. Some of the up-regulated transcripts in the suppressor overexpressing strains exposed to COS included genes involved in transcription, cell cycle, stress response and the Ras signal transduction pathway. Down-regulated transcripts included those encoding protein folding components and respiratory chain proteins. The COS-induced transcriptional response is distinct from previously described environmental stress responses (i.e. thermal, salt, osmotic and oxidative stress and pre-treatment with these well characterized environmental stressors provided little or any resistance to COS. Conclusions Overexpression of the ARL1 gene, a member of the Ras superfamily that regulates membrane

  3. Iodine-125 Chitosan-Vitamin C complex. Preparation, characterization and application

    Energy Technology Data Exchange (ETDEWEB)

    Elbarbary, Ahmed M. [National Center for Radiation Research and Technology, Cairo (Egypt). Polymer Chemistry Dept.; Shafik, H.M.; Ebeid, N.H.; Ayoub, S.M. [Atomic Energy Authority, Cairo (Egypt). Hot Lab. Center; Othman, Sameh H. [Atomic Energy Authority, Cairo (Egypt). Nuclear Research Center

    2015-07-01

    In heterogeneous conditions, water soluble Chitosan-Vitamin C Complex (CSVC) is successfully synthesized via the ionic interaction between γ-degraded CS and VC. Chitosan (CS) of low molecular weight (MW) is prepared using γ-irradiation method. The coupling of CS and vitamin C (VC) is carried out by the chemical treatment of VC with the γ-degraded CS. The formation of CSVC complex instead of physical mixture is confirmed by FT-IR and UV spectrometry. Characterization by transmission electron microscope (TEM) and dynamic light scattering (DLS) shows the formation of a nanostructure in 40 nm range. The preparation of labeled CSVC was performed using chloramines-T oxidation method. The labeling feasibility of CSVC nanostructure by Iodine-125 ({sup 125}I) is investigated. The optimized conditions of labeling are thought to be 50 μg of oxidizing agent, pH 3, and one minute reaction time. The Biodistribution activity of {sup 125}I radiolabeled CSVC nanostructure ({sup 125}I-CSVC) is examined on a group of different ascites tumor bearing mice. Calculation of the biodistribution percentages shows that the tumor, liver, and kidney are the targeting organs of {sup 125}I-CSVC nanostructure.

  4. Iodine-125 Chitosan-Vitamin C complex. Preparation, characterization and application

    International Nuclear Information System (INIS)

    Elbarbary, Ahmed M.; Shafik, H.M.; Ebeid, N.H.; Ayoub, S.M.; Othman, Sameh H.

    2015-01-01

    In heterogeneous conditions, water soluble Chitosan-Vitamin C Complex (CSVC) is successfully synthesized via the ionic interaction between γ-degraded CS and VC. Chitosan (CS) of low molecular weight (MW) is prepared using γ-irradiation method. The coupling of CS and vitamin C (VC) is carried out by the chemical treatment of VC with the γ-degraded CS. The formation of CSVC complex instead of physical mixture is confirmed by FT-IR and UV spectrometry. Characterization by transmission electron microscope (TEM) and dynamic light scattering (DLS) shows the formation of a nanostructure in 40 nm range. The preparation of labeled CSVC was performed using chloramines-T oxidation method. The labeling feasibility of CSVC nanostructure by Iodine-125 ( 125 I) is investigated. The optimized conditions of labeling are thought to be 50 μg of oxidizing agent, pH 3, and one minute reaction time. The Biodistribution activity of 125 I radiolabeled CSVC nanostructure ( 125 I-CSVC) is examined on a group of different ascites tumor bearing mice. Calculation of the biodistribution percentages shows that the tumor, liver, and kidney are the targeting organs of 125 I-CSVC nanostructure.

  5. Synthesis of magnetite/graphene oxide/chitosan composite and its application for protein adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Nengsheng, E-mail: yensh@cnu.edu.cn; Xie, Yali; Shi, Pengzhi; Gao, Ting; Ma, Jichao

    2014-12-01

    In this study, a facile and novel strategy was developed to fabricate magnetite/graphene oxide/chitosan (Fe{sub 3}O{sub 4}/GO/CS) composite, and the composite was used as a magnetic adsorbent for the enrichment of protein, and followed by matrix-assisted laser desorption ionization mass spectrometry (MALDI-TOF MS) analysis. The phase composition, chemical structure and morphology of the composite were characterized by X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), transmission electron microscopy (TEM), scanning electronic microscope (SEM) and vibrating sample magnetometer (VSM). Protein cytochrome c was chosen as model target to evaluate the adsorptive property of Fe{sub 3}O{sub 4}/GO/CS. After enrichment procedure and magnetic separation, protein bounded with the material was analyzed by MALDI-TOF MS without desorption. The results indicated that Fe{sub 3}O{sub 4}/GO/CS composite exhibited a good adsorptive capacity for protein, and Fe{sub 3}O{sub 4}/GO/CS composite had a promising potential in magnetic separation research. - Highlights: • Magnetite/graphene oxide/chitosan composite was synthesized by novel route. • The composite was used as magnetic absorbent for protein enrichment. • The composite had excellent adsorption performance for protein enrichment.

  6. Thermo-responsive hydroxybutyl chitosan hydrogel as artery intervention embolic agent for hemorrhage control.

    Science.gov (United States)

    Sun, Guohui; Feng, Chao; Jiang, Changqing; Zhang, Tingting; Bao, Zixian; Zuo, Yajun; Kong, Ming; Cheng, Xiaojie; Liu, Ya; Chen, Xiguang

    2017-12-01

    This work targeted to investigate the potential of thermo-responsive hydroxybutyl chitosan (HBC) hydrogel using as an embolic material for occlusion of selective blood vessels. HBC hydrogel was prepared via an etherification reaction between chitosan (CS) and 1, 2-butene oxide. The hydroxybutyl groups were introduced into CS backbone, which endowed HBC hydrogel with properties of porous structure, favorable hydrophilia and rapid sol-gel interconvertibility. The gelation temperatures and gelation time respectively decreased from 30.7°C to 11.5°C and 79.60±3.19s to 7.70±1.42s at 37°C, with HBC solutions viscoelasticity increased from 3.0% to 7.0%. HBC hydrogel exhibited noncytotoxic to mouse embryo fibroblasts (MEFs) and excellent hemocompatibility with red blood cells (RBCs). After injection HBC solution into rat renal arteries, HBC solution transformed into hydrogel and attached onto blood vessel inner wall tightly, giving immediate blood vessels embolization. Meanwhile, RBCs could aggregate around HBC hydrogel to form moderate coagulation, which was beneficial to avoid hydrogel migration with blood flow. Above results suggested that HBC hydrogel could be applied as a promising embolic agent for hemorrage in the interventional vascular embolization field. Copyright © 2017. Published by Elsevier B.V.

  7. Development of chitosan-coated gold nanoflowers as SERS-active probes

    Science.gov (United States)

    Xu, Dan; Gu, Jiangjiang; Wang, Weina; Yu, Xuehai; Xi, Kai; Jia, Xudong

    2010-09-01

    Surface-enhanced Raman scattering (SERS) has been intensely researched for many years as a potential technique for highly sensitive detection. This work, through the reduction of HAuCl4 with pyrrole in aqueous solutions, investigated a facile one-pot synthesis of flower-like Au nanoparticles with rough surfaces. The formation process of the Au nanoflowers (AuNFs) was carefully studied, and a spontaneous assembly mechanism was proposed based on the time-course experimental results. The key synthesis strategy was to use pyrrole as a weak particle stabilizing and reducing agent to confine crystal growth in the limited ligand protection region. The nanometer-scale surface roughness of AuNFs provided several hot spots on a single particle, which significantly increased SERS enhancement. Good biocompatible stable Raman-active probes were synthesized by coating AuNFs with chitosan. The conservation of the SERS effects in living cells suggested that the chitosan-capped AuNFs could be suitable for highly sensitive detection and have potential for targeting of tumors in vivo.

  8. Preparation of catechol-linked chitosan/carbon nanocomposite-modified electrode and its applications

    Energy Technology Data Exchange (ETDEWEB)

    Jirimali, Harishchandra Digambar; Saravanakumar, Duraisamy; Shin, Woon Sup [Dept. of Chemistry and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Seoul (Korea, Republic of)

    2015-04-15

    In this study, we report the synthesis of 2,3-dihydroxybenzaldehyde (catechol)-linked chitosan (cat-chitosan) and the preparation of its composite with carbon (cat-chitosan/carbon) to construct a catechol-modified electrode. The synthesis is similar to our previous work on hydroquinone–chitosan/carbon composite electrode. We synthesized catechol-linked chitosan polymer and prepared the its composite electrode with carbon. The catchitosan/carbon composite electrode shows a reversible confined redox behavior by the catechol functional group. The electrode catalyzes the oxidation of NADH. It has Cu{sup 2+} ion-binding capability and its binding constant 8.7 μM.

  9. Surface modification of an Mg-1Ca alloy to slow down its biocorrosion by chitosan

    International Nuclear Information System (INIS)

    Gu, X N; Zheng, Y F; Lan, Q X; Cheng, Y; Xi, T F; Zhang, Z X; Zhang, D Y

    2009-01-01

    The surface morphologies before and after immersion corrosion test of various chitosan-coated Mg-1Ca alloy samples were studied to investigate the effect of chitosan dip coating on the slowdown of biocorrosion. It showed that the corrosion resistance of the Mg-Ca alloy increased after coating with chitosan, and depended on both the chitosan molecular weight and layer numbers of coating. The Mg-Ca alloy coated by chitosan with a molecular weight of 2.7 x 10 5 for six layers has smooth and intact surface morphology, and exhibits the highest corrosion resistance in a simulated body fluid.

  10. Surface modification of an Mg-1Ca alloy to slow down its biocorrosion by chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Gu, X N; Zheng, Y F; Lan, Q X [State Key Laboratory for Turbulence and Complex System and College of Engineering, Peking University, Beijing 100871 (China); Cheng, Y; Xi, T F [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zhang, Z X [Biomedical Engineering Research Center, Research Institute of Peking University in Shenzhen, Shenzhen 518057 (China); Zhang, D Y, E-mail: gxn139888@pku.edu.c, E-mail: yfzheng@pku.edu.c, E-mail: 8lanqiuxiang@163.co, E-mail: chengyan@pku.edu.c, E-mail: top5460@163.co, E-mail: xitingfei@tom.co, E-mail: zhangdeyuan@lifetechmed.co [Lifetech Scientific (Shenzhen) Co. Ltd, Hi-Tech Park, Shenzhen 518000 (China)

    2009-08-15

    The surface morphologies before and after immersion corrosion test of various chitosan-coated Mg-1Ca alloy samples were studied to investigate the effect of chitosan dip coating on the slowdown of biocorrosion. It showed that the corrosion resistance of the Mg-Ca alloy increased after coating with chitosan, and depended on both the chitosan molecular weight and layer numbers of coating. The Mg-Ca alloy coated by chitosan with a molecular weight of 2.7 x 10{sup 5} for six layers has smooth and intact surface morphology, and exhibits the highest corrosion resistance in a simulated body fluid.

  11. Surface modification of an Mg-1Ca alloy to slow down its biocorrosion by chitosan.

    Science.gov (United States)

    Gu, X N; Zheng, Y F; Lan, Q X; Cheng, Y; Zhang, Z X; Xi, T F; Zhang, D Y

    2009-08-01

    The surface morphologies before and after immersion corrosion test of various chitosan-coated Mg-1Ca alloy samples were studied to investigate the effect of chitosan dip coating on the slowdown of biocorrosion. It showed that the corrosion resistance of the Mg-Ca alloy increased after coating with chitosan, and depended on both the chitosan molecular weight and layer numbers of coating. The Mg-Ca alloy coated by chitosan with a molecular weight of 2.7 x 10(5) for six layers has smooth and intact surface morphology, and exhibits the highest corrosion resistance in a simulated body fluid.

  12. Modified carbohydrate-chitosan compounds, methods of making the same and methods of using the same

    Science.gov (United States)

    Venditti, Richard A; Pawlak, Joel J; Salam, Abdus; El-Tahlawy, Khaled Fathy

    2015-03-10

    Compositions of matter are provided that include chitosan and a modified carbohydrate. The modified carbohydrate includes a carbohydrate component and a cross linking agent. The modified carbohydrate has increased carboxyl content as compared to an unmodified counterpart carbohydrate. A carboxyl group of the modified carbohydrate is covalently bonded with an amino group of chitosan. The compositions of matter provided herein may include cross linked starch citrate-chitosan and cross linked hemicellulose citrate-chitosan, including foams thereof. These compositions yield excellent absorbency and metal chelation properties. Methods of making cross linked modified carbohydrate-chitosan compounds are also provided.

  13. Preparation of catechol-linked chitosan/carbon nanocomposite-modified electrode and its applications

    International Nuclear Information System (INIS)

    Jirimali, Harishchandra Digambar; Saravanakumar, Duraisamy; Shin, Woon Sup

    2015-01-01

    In this study, we report the synthesis of 2,3-dihydroxybenzaldehyde (catechol)-linked chitosan (cat-chitosan) and the preparation of its composite with carbon (cat-chitosan/carbon) to construct a catechol-modified electrode. The synthesis is similar to our previous work on hydroquinone–chitosan/carbon composite electrode. We synthesized catechol-linked chitosan polymer and prepared the its composite electrode with carbon. The catchitosan/carbon composite electrode shows a reversible confined redox behavior by the catechol functional group. The electrode catalyzes the oxidation of NADH. It has Cu"2"+ ion-binding capability and its binding constant 8.7 μM.

  14. Comparing the Effectivities of Chitosan Citrate and Chitosan Acetate in Eradicating Enterococcus faecalis Biofilm

    Directory of Open Access Journals (Sweden)

    Uppalavanna Witedja

    2018-01-01

    Full Text Available Introduction: Adequate biomechanical preparations, antibacterial irrigants, and intracanal medications to promote the elimination of bacteria and their products are required to succeed root canal treatment. Enterococcus faecalis with its biofilm is known as an important etiological agent in endodontic treatment failures. Chitosan, as a natural product, has an antibacterial activity and is considered less toxic to the periapical tissue than other irrigants. However, the use of this natural product needs to be examined to determine its effectiveness as a root canal irrigant in endodontic treatment; this can be done by comparing it with the most common endodontic irrigant (NaOCl 5.25% as a positive control. Objective: The objective of the study was to compare the effectiveness between 1–3% chitosan acetate (CA and 1–3% chitosan citrate (CC against E. faecalis biofilm formation after treatment for 15, 30, and 60 minutes. Methods: The study was conducted using 12 groups, including 1–3% CA, 1–3% CC, and control groups. E. faecalis biofilms in 96-well plates were exposed to each sample for 15, 30, or 60 minutes. Subsequently, the biofilms were stained with crystal violet solution, and the optical density value was measured using a microtiter plate reader at a wavelength of 600nm. Results: CA and CC were effective in eradicating E. faecalis biofilm. However, the levels of effectiveness of CC and CA depended on the concentration and application time. Three-way analysis of variance (ANOVA showed a significant difference between the irrigants (F = 5.92; p<0.05 and three application times (F = 6.50; p< 0.05. The CA was effective in eradicating biofilm after 15 minutes of application, whereas the CC was more effective after 30 and 60 minutes of application. Conclusion: CC and CA are both effective in eradicating E. faecalis biofilm.

  15. Spectroscopic analysis of the powdery complex chitosan-iodine

    Science.gov (United States)

    Gegel, Natalia O.; Babicheva, Tatyana S.; Belyakova, Olga A.; Lugovitskaya, Tatyana N.; Shipovskaya, Anna B.

    2018-04-01

    A chitosan-iodine complex was obtained by modification of polymer powder in the vapor of an iodine-containing sorbate and studied by electron and IR spectroscopy, optical rotation dispersion. It was found that the electronic spectra of an aqueous solution of the modified chitosan (the source one and that stored for a year) showed intense absorption bands of triiodide and iodate ions, and also polyiodide ions, bound to the macromolecule by exciton bonding with charge transfer. Analysis of the IR spectra shows destruction of the network of intramolecular and intermolecular hydrogen bonds in the iodinated chitosan powder in comparison with the source polymer and the formation of a new chemical substance. E.g., the absorption band of deformation vibrations of the hydroxyl group disappears in the modified sample, and that of the protonated amino group shifts toward shorter wavelengths. The intensity of the stretching vibration band of the glucopyranose ring atoms significantly reduces. Heating of the modified sample at a temperature below the thermal degradation point of the polymer leads to stabilization of the chitosan-iodine complex. Based on our studies, the hydroxyl and amino groups of the aminopolysaccharide have been recognized as the centers of retention of polyiodide chains in the chitosan matrix.

  16. Chitosan-based polyherbal toothpaste: As novel oral hygiene product

    Directory of Open Access Journals (Sweden)

    Mohire Nitin

    2010-01-01

    Full Text Available Objective: The objective of the present work was to develop chitosan-based polyherbal toothpaste and evaluate its plaque-reducing potential and efficacy in reduction of dental pathogens. Materials and Methods: Antimicrobial activity of herbal extracts against dental pathogens were performed by using disk diffusion method. The pharmaceutical evaluation of toothpaste was carried out as per the US Government Tooth Paste Specifications. A 4-week clinical study was conducted in patients with oro-dental problems to evaluate the plaque removing efficacy of chitosan-based polyherbal toothpaste with commercially available chlorhexidine gluconate (0.2% w/v mouthwash as positive control. Total microbial count was carried out to determine the percentage decrease in the oral bacterial count over the period of treatment. Result: Herbal extracts were found to possess satisfactory antimicrobial activity against most of the dental pathogens. Chitosan-containing polyherbal toothpaste significantly reduces the plaque index by 70.47% and bacterial count by 85.29%, and thus fulfills the majority of esthetic and medicinal requirements of oral hygiene products. Conclusion: Chitosan-based polyherbal toothpaste proves itself as a promising novel oral hygiene product as compared with currently available oral hygiene products. A further study to confirm the exact mechanism and active constituents behind antiplaque and antimicrobial activity of chitosan-based polyherbal toothpaste and its efficacy in large number of patient population is on high demand.

  17. 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.

  18. Electrophoretic deposition of composite hydroxyapatite-chitosan coatings

    International Nuclear Information System (INIS)

    Pang Xin; Zhitomirsky, Igor

    2007-01-01

    Cathodic electrophoretic deposition has been utilized for the fabrication of composite hydroxyapatite-chitosan coatings on 316L stainless steel substrates. The addition of chitosan to the hydroxyapatite suspensions promoted the electrophoretic deposition of the hydroxyapatite nanoparticles and resulted in the formation of composite coatings. The obtained coatings were investigated by X-ray diffraction, thermogravimetric and differential thermal analysis, scanning and transmission electron microscopy, potentiodynamic polarization measurements, and electrochemical impedance spectroscopy. It was shown that the deposit composition can be changed by a variation of the chitosan or hydroxyapatite concentration in the solutions. Experimental conditions were developed for the fabrication of hydroxyapatite-chitosan nanocomposites containing 40.9-89.8 wt.% hydroxyapatite. The method enabled the formation of adherent and uniform coatings of thicknesses up to 60 μm. X-ray studies revealed that the preferred orientation of the hydroxyapatite nanoparticles in the chitosan matrix increases with decreasing hydroxyapatite content in the composite coatings. The obtained coatings provided the corrosion protection for the 316L stainless steel substrates

  19. Significance of Glucose Addition on Chitosan-Glycerophosphate Hydrogel Properties

    Directory of Open Access Journals (Sweden)

    Dian Susanthy

    2016-03-01

    Full Text Available Chitosan-glycerophosphate hydrogel can be used as dental scaffold due to its thermosensitivity, gelation performance at body temperature, suitable acidity for body condition, biocompatibility, and ability to provide good environment for cell proliferation and differentiation. Previous study showed that glucose addition to the chitosan solution before steam sterilization improved its hydrogel mechanical strength. However, the effectiveness of glucose addition was still doubted because glucose might undergo Maillard reaction in that particular condition. The aims of this study are to confirm whether the glucose addition can increase the hydrogel mechanical strength and gelation rate effectively and also to compare their performance to be dental scaffold. This research was performed through several steps, namely preparation of chitosan-glycerophosphate solution, addition of glucose, gelation time test, gel mechanical strength measurement, functional group analysis, and physical properties measurements (pH, viscosity, and pore size. The result showed that glucose addition did not improve the hydrogel mechanical strength and gelation rate, neither when it was added before nor after steam sterilization. Glucose addition before steam sterilization seemed to trigger Maillard reaction or browning effect, while glucose addition after steam sterilization increased the amount of free water molecules in the hydrogel. Chitosan and glycerophosphate interact physically, but interaction between chitosan and glucose seems to occur chemically and followed by the formation of free water molecules. Glucose addition decreases the solution viscosity and hydrogel pore size so the hydrogel performance as dental scaffold is lowered.

  20. Physiochemical and optical properties of chitosan based graphene oxide bionanocomposite.

    Science.gov (United States)

    Kumar, Santosh; Koh, Joonseok

    2014-09-01

    In the present investigation an ecofriendly approach and a simple homogeneous solution casting method led to the development of biodegradable chitosan/graphene oxide bionanocomposites. The formation of bionanocomposite was confirmed by UV-vis, FT-IR, Raman spectroscopy, XRD, and further evaluated by thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The circular dichroism (CD) study of chitosan/graphene oxide revealed that the intensity of the negative transition band at wavelength of 200-222 nm decreased with the different pH of chitosan/graphene oxide solutions. It was also found that the pH conditions affect the interaction between chitosan and graphene oxide. Optical properties of chitosan/graphene oxide are evaluated by photoluminescence (PL) spectroscopy which showed blue shift at excitation wavelength of 255 nm compared to graphene oxide. These results strongly suggest that the bionanocomposite materials may open new vistas in biotechnological, biosensor and biomedical applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. 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%.

  2. POTENTIAL ANTISTATIC PROPERTIES OF A CEMENT COMPOSITION MODIFIED BY CHITOSAN

    Directory of Open Access Journals (Sweden)

    Darchiya Valentina Ivanovna

    2012-10-01

    Full Text Available Environmental compatibility of construction materials and their impact onto the human organism and the environment are the essential factors to be taken account of in the course of construction. Therefore, natural renewable biological polymers arouse interest. Polysaccharide chitin takes a special position among them. It represents one of the most widely spread biological polymers; it is extracted from 100% renewable materials. It is part of the external skeleton of crustaceans and insects, and it also part of cell walls of mushrooms and algae. Any research of potential materials to be generated from chitin and its derivative chitosan may involve a practical implementation. The research of the antistatic properties followed the introduction of 1% of chitosan into the cement composition. Electrostatic field intensity was measured by Electrostatic Field Intensity Meter ST-01. The electrostatic property of the sample modified by chitosan turned out to be lower than the one of the benchmark sample by 5.6 times. The presence of chitosan in the cement composition makes no impact on strength-related properties of the construction material. The cement composition modified by chitosan may be used in the manufacturing of antistatic self-leveling floors.

  3. Chitosan doped with nanoparticles of copper, nickel and cobalt.

    Science.gov (United States)

    Cárdenas-Triviño, Galo; Elgueta, Carolina; Vergara, Luis; Ojeda, Javier; Valenzuela, Ariel; Cruzat, Christian

    2017-11-01

    Metal colloids in 2 propanol using nanoparticles (NPs) of copper, nickel and cobalt were prepared by Chemical Liquid Deposition (CLD) method. The resulting colloidal dispersions were characterized by Transmission Electron Microscopy (TEM). The colloids were supported in chitosan. Then, microbiological assays were performed using E. coli and S. aureus in order to determine the bactericide/bacteriostatic activity of nanoparticles (NPs) trapped or chelated with chitosan. Finally, the toxicity of the metal colloids Cu, Ni and Co was tested. Bio-assays were conducted in three different animal species. First of all on earth warms (Eisenia foetida) to evaluate the toxicity and the biocompatibility of chitosan in lactic acid (1% and 0.5%). Secondly bio-assay done in fishes (rainbow trout), the liver toxicity of NPs in vivo was evaluated. Finally, a bio-assay was conducted in Sprange-Dawley rats of 100g weight, which were injected intraperitoneally with different solutions of chitosan metal colloids. Then, the minimum and maximum concentration were determined for copper, nickel and cobalt. The purpose of the use of chitosan was acting as a carrier for some magnetic NPs, which toxicity would allow to obtain new polymeric materials with potential applications as magnet future drugs carrier. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Sorption characteristics of technetium on crosslinked chitosan from aqueous solution

    International Nuclear Information System (INIS)

    Pivarciova, L.; Rosskopfova, O.; Galambos, M.; Rajec, P.

    2014-01-01

    Sorption of technetium on crosslinked chitosan was studied using batch techniques in static arrangement of experiment under aerobic conditions at laboratory temperature. The adsorption of technetium was rapid and the percentage of the technetium sorption was > 98 %. In the pH range of 3-11 adsorption of technetium on crosslinked chitosan was > 98 %. The competition effect of Fe 3+ towards TcO 4 - sorption on crosslinked chitosan was stronger than the competition effect of other observed cations. The selectivity of crosslinked chitosan for these cations in solution with the concentration above 1·10 -3 mol·dm -3 was in the order Fe 3+ > Ca 2+ > Na + > Fe 2+ . The competition effect of (ClO 4 ) - towards TcO 4 - sorption was stronger than the competition effect of (SO 4 ) 2 - ions. From these results it can be expected that crosslinked chitosan could be a suitable sorbent for the immobilization of technetium in the liquid radioactive waste. (authors)

  5. Biokinetic studies on 14C-chitosan in rats

    International Nuclear Information System (INIS)

    Jia Minghong; Nishimura, Y.; Watanabe, Y.; Yukawa, M.

    1998-05-01

    The absorption and the basic metabolism of chitosan in rats are investigated. The results indicated that 14 C-chitosan from gastrointestinal tract was absorbed, metabolized and excreted quickly without re-bioavailability. The radioactive compounds perhaps with specifically chemical forms in serum, liver and the contents of small intestines were separated on GPC column and measured by radioactivity counting. A big pile of peaks with the retention volume almost same as that of standard 14 C-chitosan and another sharp one with the retention volume in the range of higher molecular weight same as that of BSA were discovered in analysis respectively for contents of intestine and serum or liver. The sharp peak would disappear if the proteins contained in the serum or liver were removed. In addition, and interesting tail peak, followed with the pile ones and eluted with the retention volume of lower molecular weight range same as that of chitooligosaccharides was also found in each of the 3 samples, ignoring the protein removal or not. These results suggested that most of 14 C-chitosan was not to be digested in intestine. On the other hand, a small amount of 14 C-chitosan was likely to be absorbed directly or after degraded to small molecular compounds into blood, liver and other tissues, and then connected with the proteins. Perhaps it is these trace materials that were playing important roles in reduction of the bioavailability of radiostrontium in rats

  6. Immunological evaluation of chitosan nanoparticles loaded with tetanus toxoid.

    Science.gov (United States)

    Ghalavand, M; Saadati, M; Ahmadi, A; Abbasi, E; Salimian, J

    2018-01-01

    The present study was aimed at comparing tetanus toxoid (TT)‑loaded-chitosan nanoparticles with aluminum hydroxide as a common vaccine adjuvant. Tetanus remains to be a major public health problem. Nanoparticles have been extensively used as immune adjuvants. Tetanus toxoid (TT) encapsulated in chitosan nanoparticles is considered to be a promising tetanus vaccine candidate. TT‑loaded chitosan nanoparticles were prepared by the ionic gelation method. The nanoparticles were studied by SEM for their size and morphology. In vivo study was conducted to evaluate the immunity response using mice divided into 4 groups and injected with encapsulated toxoid. The immune responses were then measured using indirect ELISA. The purity and integrity of antigen were confirmed by SDS-PAGE electrophoresis. The size of nanoparticles was estimated at 100 nm. As a result, the IgG antibody levels were 1.9, 1.76, and 0.87 in chitosan nanoparticles, aluminum hydroxide, and TT alone groups, respectively. Also, the immune responses were significantly higher in immunized groups compared to control groups vaccinated with free adjuvant vaccines (p chitosan nanoparticles were reasonable. It enhanced the immune responses as much as aluminum hydroxide adjuvant does and thus may be a good alternative candidate (Tab. 1, Fig. 3, Ref. 16).

  7. Antimicrobial Properties of Chitosan-Alumina/f-MWCNT Nano composites

    International Nuclear Information System (INIS)

    Masheane, M.; Nthunya, L.; Malinga, S.; Masheane, M.; Nthunya, L.; Nxumalo, E.; Mhlanga, S.; Barnard, T.

    2016-01-01

    Antimicrobial chitosan-alumina/functionalized-multi walled carbon nano tube (f-MWCNT) nano composites were prepared by a simple phase inversion method. Scanning electron microscopy (SEM) analyses showed the change in the internal morphology of the composites and energy dispersive spectroscopy (EDS) confirmed the presence of alumina and f-MWCNTs in the chitosan polymer matrix. Fourier transform infrared (FTIR) spectroscopy showed the appearance of new functional groups from both alumina and f-MWCNTs, and thermogravimetric analysis (TGA) revealed that the addition of alumina and f-MWCNTs improved the thermal stability of the chitosan polymer. The presence of alumina and f-MWCNTs in the polymer matrix was found to improve the thermal stability and reduced the solubility of chitosan polymer. The prepared chitosan-alumina/f-MWCNT nano composites showed inhibition of twelve strains of bacterial strains that were tested. Thus, the nano composites show a potential for use as a biocides in water treatment for the removal of bacteria at different environmental conditions.

  8. Adherence of paclitaxel drug in magnetite chitosan nanoparticles

    International Nuclear Information System (INIS)

    Escobar Zapata, Edna V.; Martínez Pérez, Carlos A.; Rodríguez González, Claudia A.; Castro Carmona, Javier S.; Quevedo Lopez, Manuel A.; García-Casillas, Perla E.

    2012-01-01

    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. Chitosan Based Regenerated Cellulose Fibers Functionalized with Plasma and Ultrasound

    Directory of Open Access Journals (Sweden)

    Urška Vrabič Brodnjak

    2018-04-01

    Full Text Available The great potential of regenerated cellulose fibers, which offer excellent possibilities as a matrix for the design of bioactive materials, was the lead for our research. We focused on the surface modification of fibers to improve the sorption properties of regenerated cellulose and biocomposite regenerated cellulose/chitosan fibers, which are on the market. The purpose of our investigation was also the modification of regenerated cellulose fibers with the functionalization by chitosan as a means of obtaining similar properties to biocomposite regenerated cellulose/chitosan fibers on the market. Argon gas plasma was used for fiber surface activation and chitosan adsorption. Ultrasound was also used as a treatment procedure for the surface activation of regenerated cellulose fibers and treatment with chitosan. Analyses have shown that ultrasonic energy or plasma change the accessibility of free functional groups, structure and reactivity, especially in regenerated cellulose fibers. Changes that occurred in the morphology and in the structure of fibers were also reflected in their physical and chemical properties. Consequently, moisture content, sorption properties and water retention improved.

  10. COMPARATIVE ANALYSIS OF TECHNILOGIES OF CHITOSAN PRODUCTION FROM DEAD BEES

    Directory of Open Access Journals (Sweden)

    Marina Abramova

    2017-07-01

    Full Text Available Objective: The aim of this work is to study the characteristics of technology of chitosan obtaining from unconventional sources, namely from dead bees. Methods: The article considers three methods of chitosan obtaining from dead bees, namely the technology with the usage of dead bees with low degree of drying; the technology with the usage of dead bees with high degree of drying; the technology with the usage of dead bees with high degree of drying but without separation of deproteination and deacetylation stages. Results: It is proved that the technology with the usage of dead bees with high degree of drying but without separation of deproteination and deacetylation stages does not require high temperatures and long time. Yield of chitosan with the use of this technology is 21-24%. Discussion: The expediency of dead bees usage as raw material for the production of chitosan in Ukraine is shown. The technologies of chitosan obtaining from dead bees are compared, the most efficient one is chosen, which provide the highest yield of the finished product, so it is the most promising for the application in practice.

  11. Chitosan/bentonite bionanocomposites: morphology and mechanical behavior

    International Nuclear Information System (INIS)

    Braga, C.R.C.; Melo, F.M.A. de; Vitorino, I.F.; Fook, M.V.L.; Silva, S.M.L.

    2010-01-01

    This study chitosan/bentonite bionanocomposite films were prepared by solution intercalation process, seeking to investigate the effect of the chitosan/bentonite ratio (5/1 e 10/1) on the morphology and mechanical behavior of the bionanocomposites. It was used as nanophase, Argel sodium bentonite (AN), was provided by Bentonit Uniao Nordeste-BUN (Campina Grande, Brazil) and as biopolymer matrix the chitosan of low molecular weight and degree of deacetylation of 86,7% was supplied by Polymar (Fortaleza, Brazil). The bionanocomposites was investigated by X-ray diffraction and tensile properties. According to the results, the morphology and the mechanical behavior of the bionanocomposite was affected by the ratio of chitosan/bentonite. The chitosan/bentonite ratio (5/1 and 10/1) indicated the formation of an intercalated nanostructure and of the predominantly exfoliated nanostructure, respectively. And the considerable increases in the resistance to the traction were observed mainly for the bionanocomposite with predominantly exfoliated morphology. (author)

  12. Single molecule atomic force microscopy and force spectroscopy of chitosan.

    Science.gov (United States)

    Kocun, Marta; Grandbois, Michel; Cuccia, Louis A

    2011-02-01

    Atomic force microscopy (AFM) and AFM-based force spectroscopy was used to study the desorption of individual chitosan polymer chains from substrates with varying chemical composition. AFM images of chitosan adsorbed onto a flat mica substrate show elongated single strands or aggregated bundles. The aggregated state of the polymer is consistent with the high level of flexibility and mobility expected for a highly positively charged polymer strand. Conversely, the visualization of elongated strands indicated the presence of stabilizing interactions with the substrate. Surfaces with varying chemical composition (glass, self-assembled monolayer of mercaptoundecanoic acid/decanethiol and polytetrafluoroethylene (PTFE)) were probed with chitosan modified AFM tips and the corresponding desorption energies, calculated from plateau-like features, were attributed to the desorption of individual polymer strands. Desorption energies of 2.0±0.3×10(-20)J, 1.8±0.3×10(-20)J and 3.5±0.3×10(-20)J were obtained for glass, SAM of mercaptoundecanoic/dodecanethiol and PTFE, respectively. These single molecule level results can be used as a basis for investigating chitosan and chitosan-based materials for biomaterial applications. Copyright © 2010 Elsevier B.V. All rights reserved.

  13. An Overview of Chitosan Nanoparticles and Its Application in Non-Parenteral Drug Delivery

    Directory of Open Access Journals (Sweden)

    Munawar A. Mohammed

    2017-11-01

    Full Text Available The focus of this review is to provide an overview of the chitosan based nanoparticles for various non-parenteral applications and also to put a spotlight on current research including sustained release and mucoadhesive chitosan dosage forms. Chitosan is a biodegradable, biocompatible polymer regarded as safe for human dietary use and approved for wound dressing applications. Chitosan has been used as a carrier in polymeric nanoparticles for drug delivery through various routes of administration. Chitosan has chemical functional groups that can be modified to achieve specific goals, making it a polymer with a tremendous range of potential applications. Nanoparticles (NP prepared with chitosan and chitosan derivatives typically possess a positive surface charge and mucoadhesive properties such that can adhere to mucus membranes and release the drug payload in a sustained release manner. Chitosan-based NP have various applications in non-parenteral drug delivery for the treatment of cancer, gastrointestinal diseases, pulmonary diseases, drug delivery to the brain and ocular infections which will be exemplified in this review. Chitosan shows low toxicity both in vitro and some in vivo models. This review explores recent research on chitosan based NP for non-parenteral drug delivery, chitosan properties, modification, toxicity, pharmacokinetics and preclinical studies.

  14. Degradation of chitosan by gamma ray with presence of hydrogen peroxide

    Science.gov (United States)

    Mahmud, Maznah; Naziri, Muhammad Ihsan; Yacob, Norzita; Talip, Norhashidah; Abdullah, Zahid

    2014-02-01

    The radiation degraded chitosan samples were prepared by swelling the chitosan powder in water and exposed for gamma irradiation. The ratio chitosan to water was 1:6 with the presence of hydrogen peroxide (H2O2), 1%-5%. These chitosan-water mixtures were irradiated at 6kGy, which is the lowest irradiation dose that facility can offered. All samples were purified and proceed with characterization. The molecular weight (MW) study was monitored by size exclusion chromatography-multi angle laser light scattering (SEC-MALLS). Results showed that MW of chitosan reduced as the dose increased. Application of H2O2 enhanced the degradation rate of chitosan even at very low irradiation dose. Homogenous degradation also occurred during treatment with H2O2based on the polydispersity index (PDI) derived from the calculation of weight average molecular weight over number average molecular weight (Mw/Mn). Mechanism of chitosan radiation degradation with and without hydrogen peroxide was also discussed in this paper. Structure of degraded products was characterized with Fourier-transform infrared spectra. The degree of deacetylation (DDA) values of the samples was determined by acid-base titration. Solubility test results showed that, chitosan powder even at low Mw was insoluble in water even at low pH water. Chitosan as well as irradiated chitosan powder are soluble in strong and weak acid solution. Further discussion on behaviours of radiation degraded chitosan will be elaborated more in this paper.

  15. 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.

  16. Effect of chitosan solution on the inhibition of Acidovorax citrulli causing bacterial fruit blotch of watermelon.

    Science.gov (United States)

    Li, Bin; Shi, Yu; Shan, Changlin; Zhou, Qing; Ibrahim, Muhammad; Wang, Yanli; Wu, Guoxing; Li, Hongye; Xie, Guanlin; Sun, Guochang

    2013-03-30

    The production of watermelon in China has been seriously hampered by fruit blotch disease and limited control measures are now applied. Chitosan has been employed to control a variety of plant diseases and is considered to be the most promising biochemical to control this disease. The in vitro antibacterial effect of chitosan and its ability in protection of watermelon seedlings from bacterial fruit blotch were evaluated. Results showed that three types of chitosan, in particular, chitosan A at 0.40 mg mL⁻¹ significantly inhibited the growth of Acidovorax citrulli. The antibacterial activity of chitosan A was affected by chitosan concentration and incubation time. The direct antibacterial activity of chitosan may be attributed to membrane lysis evidenced by transmission electron microscopic observation. The disease index of watermelon seedlings planted in soil and the death rate of seedlings planted in perlite were significantly reduced by chitosan A at 0.40 mg mL⁻¹ compared to the pathogen control. Fresh and dry weight of watermelon seedlings planted in soil was increased by chitosan seed treatment, but not by chitosan leaf spraying. The results indicated that chitosan solution may have a potential in controlling bacterial fruit blotch of watermelon. © 2013 Society of Chemical Industry.

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

    International Nuclear Information System (INIS)

    Kim, Y. H.; Bom, H. S.; Kim, J. Y.; Roh, Y. B.

    1997-01-01

    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 ( 85 Sr). Chitosan or calcium(CaCl 2 ) 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 85 Sr 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 85 SrCl 2 (0.25μCi). In control group, no chitosan or calcium were given. Either chitosan or calcium was effective on the removal of 85 Sr from mouse body (Table 1). Addition of calcium on chitosan did not improve or deteriorate the effect of chitosan on the removal of 85 Sr from mouse body. In conclusion, calcium was similarly effective on the removal of 85 Sr from mouse body. (author)

  18. Structural and antimicrobial properties of irradiated chitosan and its complexes with zinc

    International Nuclear Information System (INIS)

    Khan, Azam; Mehmood, Shaukat; Shafiq, Muhammad; Yasin, Tariq; Akhter, Zareen; Ahmad, Shabir

    2013-01-01

    The aim of this research was to evaluate the structural and antimicrobial properties of irradiated chitosan and its complexes with zinc. Chitosan having a molecular weight (M η ) of 220 kDa was exposed to gamma rays in dry, wet and solution forms. The chitosan-zinc complexes were prepared by varying the M η of chitosan and Zn content. Viscometeric analysis revealed a sharp decrease in the M η of chitosan irradiated in solution form even at lower doses compared with the dry and wet forms. X-ray diffraction patterns demonstrated variation in the crystallinity of chitosan upon exposure to gamma rays. The antibacterial response of the irradiated chitosan and its complexes against gram-positive and gram-negative bacteria demonstrated wide spectrum of effective antimicrobial activities, which increased with the dose. Additionally, the complexes exhibited excellent antifungal activity with no growth of Aspergallious fumigatus and Fusarium solani even after two weeks. These results suggested that the irradiated chitosan and its complexes with Zn can be used as antimicrobial additives for various applications. - Highlights: • Gamma radiation is used to lower the molecular weight of chitosan. • The effect of environment on radiation degradation of chitosan is studied. • Its complexes with different amount of zinc are prepared and characterized. • Radiation-degraded chitosan and complexes showed good antibacterial properties

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

    International Nuclear Information System (INIS)

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

    2011-01-01

    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. - 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.

  20. Improving effects of chitosan nanofiber scaffolds on osteoblast proliferation and maturation

    Science.gov (United States)

    Ho, Ming-Hua; Liao, Mei-Hsiu; Lin, Yi-Ling; Lai, Chien-Hao; Lin, Pei-I; Chen, Ruei-Ming

    2014-01-01

    Osteoblast maturation plays a key role in regulating osteogenesis. Electrospun nanofibrous products were reported to possess a high surface area and porosity. In this study, we developed chitosan nanofibers and examined the effects of nanofibrous scaffolds on osteoblast maturation and the possible mechanisms. Macro- and micro observations of the chitosan nanofibers revealed that these nanoproducts had a flat surface and well-distributed fibers with nanoscale diameters. Mouse osteoblasts were able to attach onto the chitosan nanofiber scaffolds, and the scaffolds degraded in a time-dependent manner. Analysis by scanning electron microscopy further showed mouse osteoblasts adhered onto the scaffolds along the nanofibers, and cell–cell communication was also detected. Mouse osteoblasts grew much better on chitosan nanofiber scaffolds than on chitosan films. In addition, human osteoblasts were able to adhere and grow on the chitosan nanofiber scaffolds. Interestingly, culturing human osteoblasts on chitosan nanofiber scaffolds time-dependently increased DNA replication and cell proliferation. In parallel, administration of human osteoblasts onto chitosan nanofibers significantly induced osteopontin, osteocalcin, and alkaline phosphatase (ALP) messenger (m)RNA expression. As to the mechanism, chitosan nanofibers triggered runt-related transcription factor 2 mRNA and protein syntheses. Consequently, results of ALP-, alizarin red-, and von Kossa-staining analyses showed that chitosan nanofibers improved osteoblast mineralization. Taken together, results of this study demonstrate that chitosan nanofibers can stimulate osteoblast proliferation and maturation via runt-related transcription factor 2-mediated regulation of osteoblast-associated osteopontin, osteocalcin, and ALP gene expression. PMID:25246786

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

    Science.gov (United States)

    Fernandes, Julio C; Qiu, Xingping; Winnik, Francoise M; Benderdour, Mohamed; Zhang, Xiaoling; Dai, Kerong; Shi, Qin

    2012-01-01

    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. PMID:23209368

  2. Fortification of extruded snacks with chitosan: Effects on techno functional and sensory quality.

    Science.gov (United States)

    Kumar, Raushan; Xavier, K A Martin; Lekshmi, Manjusha; Balange, Amjad; Gudipati, Venkateshwarlu

    2018-08-15

    Chitosan is a dietary fibre that possesses numerous functional, technological and physiological properties useful in improving food quality. Owing to its fat absorbing ability, chitosan is widely consumed as a health supplement in the form of tablets and capsules. With a view to enhance it consumption and availability, the current work was taken up to evaluate techno-functional quality improvement of shrimp based extruded snacks fortified with chitosan. Chitosan powder at 1, 2 and 3% (w/w) level was added to the base material (corn flour and rice flour in the ratio of 70:30 and 15% Acetes powder) for extrusion. Addition of chitosan in acetes based snacks significantly reduced expansion ratio, porosity and crispiness and increased the hardness value of the product. Chitosan addition had a significant effect (p > 0.05) on the moisture retention and total protein contents of the products as well. Thiobarbituric acid reactive substances (TBARS) value of chitosan fortified extrudate showed a significantly lower value than the control sample. A higher level of chitosan also resulted in colour reduction of the final product. The FTIR spectra of extrudate confirmed the stability of chitosan during extrusion conditions. The sensory score revealed that extrudate fortified with 1% chitosan was comparable to control sample. From this study it is concluded that 1% chitosan can be incorporated in Acetes based extruded snacks for an increased level of functionality. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Study on growth-promotion of paddy plants treated with oligo chitosan

    International Nuclear Information System (INIS)

    Norhashidah Talip; Maznah Mahmud; Norzita Yacob; Kamaruddin Hashim; Khairul Zaman Mohd Dahlan

    2010-01-01

    Chitosan has been degraded to produced oligo chitosan with different molecular weight using gamma ray irradiation from a Co-60 source in solid state (powder form) and liquid state (aqueous solution). Study on growth promotion of paddy plants was done using oligo chitosan and conventional plant growth promoter as a comparison. Oligo chitosan was used with different molecular weight and different concentrations. Smaller molecular weight of oligo chitosan with smaller concentration showed better result than bigger molecular weight of oligo chitosan as a plant growth promoter. This study also showed that conventional growth promoter can be replaced with oligo chitosan as it is more effective as plant growth promoter as well as more environmental friendly. (author)

  4. Preparation of chitosan-ferulic acid conjugate: Structure characterization and in the application of pharmaceuticals.

    Science.gov (United States)

    Li, Chen; Li, Jian-Bin

    2017-12-01

    A novel drug delivery system based on chitosan derivatives was prepared by introducting ferulic acid to chitosan adopting a free radical-induced grafting procedure. This paper used an ascorbic acid/hydrogen peroxide redox pair as radical initiator. The chitosan derivative was characterized by Fourier transformed infrared (FTIR), Ultraviolet-visible spectrum (UV), Differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Electron microscopic scanning (SEM). What is more, preparing microcapsules with the chitosan conjugate as wall material, the drug release propertie of chitosan conjugates were compared with that of a blank chitosan, which treated in the same conditions but in the absence of ferulic acid. The study clearly demonstrates that free radical-induced grafting procedure was an effective reaction methods and chitosan-ferulic acid is a potential functionalized carrier material for drug delivery. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Synthesis of (2-pyridyl)-Acetyl Chitosan and Its Antioxidant Activity

    International Nuclear Information System (INIS)

    Li, Rongchun

    2011-01-01

    In this paper, chloracetyl chitosan (CACTS) was prepared at first. In the molecules of CACTS, there are active chlorine groups, which can take part in other reactions. Thus, number of chitosan derivatives will be obtained after chlorine is substituted. Choosing pyridine as the active group, a novel water-soluble chitosan derivative, (2-pyridyl)-acetyl chitosan (PACTS) was obtained and its antioxidant activity against hydroxyl radicals and superoxide radicals was assessed. The results indicated that PACTS had better antioxidant activity than that of chitosan, carboxymethyl chitosan (CMCTS), hydroxypropyl chitosan (HPCTS), and Vitamin C. And the IC 50 values against hydroxyl radicals and superoxide radicals were 0.31 mg/mL and 0.21 mg/mL, respectively

  6. Green Chemistry: Effect of Microwave Irradiationon Synthesis of Chitosan for Biomedical Grade Applications of Biodegradable Materials

    Directory of Open Access Journals (Sweden)

    Amri Setyawati

    2016-10-01

    Full Text Available Microwave assisted chitosan synthesis as biodegradable material for biomedical application has been done. The purpose of this research is to synthesis of chitosan with high DD and low molecular weight using microwave energy, the study of reaction conditions include parameters of power and reaction time. Chitosan was prepared by deacetylation of chitin with 60% NaOH solution. Conventional method has been done by reflux for 90minutes, resulting chitosan with DD of 79.5%, 72.6% yields and molecular weight 6051 g/mol. Green chemistry method using microwave radiation at 800 Watts for 5 minutes has produced chitosan with highest DD, yield and molecular weight of 86%, 75% and 3797 g/mole respectively. Synthesis of Chitosan by microwave radiation method can save 10x electrical energy for the reaction, also rapidly and effectively to produce chitosan with low molecular weight compared to conventional methods

  7. Effect of strontium addition and chitosan concentration variation on cytotoxicity of chitosan-alginate-carbonate apatite based bone scaffold

    Science.gov (United States)

    Perkasa, Rilis Eka; Umniati, B. Sri; Sunendar, Bambang

    2017-09-01

    Bone scaffold is one of the most important component in bone tissue engineering. Basically, bone scaffold is a biocompatible structure designed to replace broken bone tissue temporarily. Unlike conventional bone replacements, an advanced bone scaffold should be bioactive (e.g: supporting bone growth) and biodegradable as new bone tissue grow, while retain its mechanical properties similarity with bone. It is also possible to add more bioactive substrates to bone scaffold to further support its performance. One of the substrate is strontium, an element that could improve the ability of the bone to repair itself. However, it must be noted that excessive consumption of strontium could lead to toxicity and diseases, such as osteomalacia and hypocalcemia. This research aimed to investigate the effect of strontium addition to the cytotoxic property of chitosan-alginate-carbonate apatite bone scaffold. The amount of strontium added to the bone scaffold was 5% molar of the carbonate apatite content. As a control, bone scaffold without stronsium (0% molar) were also made. The effect of chitosan concentration variation on the cytotoxicity were also observed, where the concentration varies on 1% and 3% w/v of chitosan solution. The results showed an optimum result on bone scaffold sample with 5% molar of strontium and 3% chitosan, where 87.67% cells in the performed MTS-Assay cytotoxicity testing survived. This showed that the use of up to 5% molar addition of strontium and 3% chitosan could enhance the survivability of the cell.

  8. Aging phenomena of chitosan and chitosan-diclofenac sodium system detected by low-frequency dielectric spectroscopy.

    Science.gov (United States)

    Bodek, K H; Bak, G W

    1999-09-01

    The use of natural polymers for design of dosage form has received considerable attention recently, especially from the safety point of view. Among these polymers, chitosan shows very interesting biological, chemical and physical properties which makes it possible to use chitosan for various pharmaceutical applications. Microcrystalline chitosan (MCCh) is a special multifunctional polymeric material existing in the form of either of gelatinous water dispersion or a powder. Thermal aging of chitosan and chitosan-diclofenac sodium mixture have been studied using low-frequency dielectric measurements. The aging was carried out by annealing in ambient atmosphere in the temperature range between 25 degrees C and 100 degrees C. The dielectric losses in the aged samples proved to decrease by about one order of magnitude. The additional measurements of molecular weight distribution and infrared absorption were also carried out for better understanding of nature of the ageing phenomena. Partial evacuation of water, cross-linking and improvement of structural order may be suggested to be a result of thermal aging of the investigated materials.

  9. Development of polyamide-6/chitosan membranes for desalination

    Directory of Open Access Journals (Sweden)

    A. EL-Gendi

    2014-06-01

    Full Text Available This article deals with “developing novel polyamide-6/chitosan membranes for water desalting using wet phase inversion technique”, in which novel polyamide-6/chitosan membranes were prepared using an appropriate polymer concerning the national circumferences, along with the definition of different controlling parameters of the preparing processes and their effects on the characteristics of the produced membranes. Further, evaluation process of the fabricated sheets was undertaken. Preparation process was followed by assessment of the membrane structural characteristics; then the desalting performance of each prepared membrane was evaluated under different operating conditions in order to find the structure–property relationship. The results show that the membrane flux increases with the increase of operating pressure. The salt rejection and permeation flux have been enhanced this indicates that the chitosan (CS addition to the polyamide-6 (PA-6 membrane increases the membrane hydrophilic property. Hydraulic permeability coefficient is not stable and varies considerably with the operating pressure.

  10. PMAA-stabilized ferrofluid/chitosan/yeast composite for bioapplications

    International Nuclear Information System (INIS)

    Baldikova, Eva; Prochazkova, Jitka; Stepanek, Miroslav; Hajduova, Jana; Pospiskova, Kristyna; Safarikova, Mirka; Safarik, Ivo

    2017-01-01

    A simple, one-pot process for the preparation of magnetically responsive yeast-based biocatalysts was developed. Saccharomyces cerevisiae, Candida utilis and Kluyveromyces lactis cells were successfully incorporated into chitosan gel magnetically modified with poly(methacrylic acid)-stabilized magnetic fluid (PMAA-FF) during its formation. Magnetic PMAA-FF/chitosan/yeast composites were efficiently employed for invert sugar production. The dependence of invertase activity on used yeast, amount of magnetic biocatalyst, agitation time and after reuse was studied in detail. The tested magnetic biocatalysts retained at least 69% of their initial activity after 8 reuse cycles. - Highlights: • New types of magnetically responsive yeast biocomposites were prepared. • Recently developed PMAA-stabilized magnetic fluid was used. • Three yeast species were entrapped into magnetic chitosan gel during its formation. • All biocatalysts were efficiently employed for invert sugar formation.

  11. Characterization of collagen / chitosan films for skin regenerating scaffold

    International Nuclear Information System (INIS)

    Ismarul, I.N.; Ishak, Y.; Ismail, Z.; Mohd Shalihuddin, W.M.

    2004-01-01

    Various Proportions of chitosan/collagen films (70/30% to 95/05%) w/w were prepared and evaluated for its suitability as skin regenerating scaffold. Interactions between chitosan and collagen were studied using Fourier Transform Infrared spectroscopy (FTIR) and Differential Scanning Colorimetry (DSC). Scanning Electron Microscope (SEM) was used to investigate the morphology of the blend. Mechanical properties were evaluated using a Universal Testing Machine (UTM). The chitosan/collagen films were found to swell proportionally with time until it reaches equilibrium, FTIR spectroscopy indicated no chemical interaction between the components of the blends, DSC data indicated only one peak proving that these two materials are compatible at all proportions investigated. SEM micrographs also indicated good homogeneity between these two materials. (Author)

  12. Development of multifunctional chitosan beads for fluoride removal

    Energy Technology Data Exchange (ETDEWEB)

    Viswanathan, Natrayasamy [Department of Chemistry, Gandhigram Rural University, Gandhigram 624 302, Tamilnadu (India); Sairam Sundaram, C. [Department of Science and Humanities, Karaikal Polytechnic College, Karaikal 609 609, Puducherry (India); Meenakshi, S., E-mail: drs_meena@rediffmail.com [Department of Chemistry, Gandhigram Rural University, Gandhigram 624 302, Tamilnadu (India)

    2009-08-15

    Chitosan beads (CB) which have negligible defluoridation capacity (DC) have been chemically modified by introducing multifunctional groups, viz., NH{sub 3}{sup +} and COOH groups by means of protonation and carboxylation in order to utilize both amine and hydroxyl groups for fluoride removal. The protonated cum carboxylated chitosan beads (PCCB) showed a maximum DC of 1800 mg F{sup -}/kg whereas raw chitosan beads displayed only 52 mg F{sup -}/kg. Sorption process was found to be independent of pH and slightly influenced in the presence of other common anions. The fluoride sorption on modified forms was reasonably explained by Freundlich and Langmuir isotherms. The sorbents were characterised by FTIR and SEM with EDAX analysis. The sorption process follows pseudo-second-order and intraparticle diffusion kinetic models. The suitability of PCCB has been tested with field sample collected from a nearby fluoride endemic area.

  13. Characterization and Antiproliferative Activity of Nobiletin-Loaded Chitosan Nanoparticles

    Directory of Open Access Journals (Sweden)

    Ana G. Luque-Alcaraz

    2012-01-01

    Full Text Available Nobiletin is a polymethoxyflavonoid with a remarkable antiproliferative effect. In order to overcome its low aqueous solubility and chemical instability, the use of nanoparticles as carriers has been proposed. This study explores the possibility of binding nobiletin to chitosan nanoparticles, as well as to evaluate their antiproliferative activity. The association and loading efficiencies are 69.1% and 7.0%, respectively. The formation of an imine bond between chitosan amine groups and the carbonyl group of nobiletin, via Schiff-base, is proposed. Nobiletin-loaded chitosan nanoparticles exhibit considerable inhibition (IC50=8 μg/mL of cancerous cells, revealing their great potential for applications in cancer chemotherapy.

  14. Characterizations of Chitosan-Based Polymer Electrolyte Photovoltaic Cells

    International Nuclear Information System (INIS)

    Buraidah, M.H.; Teo, L.P.; Majid, S.R.; Yahya, R.; Taha, R.M.; Arof, A.K.

    2010-01-01

    The membranes 55 wt.% chitosan-45 wt.% NH4I, 33 wt.% chitosan-27 wt.% NH4I-40 wt.% EC, and 27.5 wt.% chitosan-22.5 wt.%?NH4I-50 wt.% buthyl-methyl-imidazolium-iodide (BMII) exhibit conductivity of 3.73 x 10-7, 7.34x10-6, and 3.43x10-5 S cm -1 , respectively, at room temperature. These membranes have been used in the fabrication of solid-state solar cells with configuration ITO/TiO 2 /polymer electrolyte membrane/ITO. It is observed that the short-circuit current density increases with conductivity of the electrolyte. The use of anthocyanin pigment obtained by solvent extraction from black rice and betalain from the callus of Celosia plumosa also helps to increase the short-circuit current.

  15. PMAA-stabilized ferrofluid/chitosan/yeast composite for bioapplications

    Energy Technology Data Exchange (ETDEWEB)

    Baldikova, Eva, E-mail: baldie@email.cz [Global Change Research Institute, CAS, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic); Department of Applied Chemistry, Faculty of Agriculture, University of South Bohemia, Branisovska 1457, 370 05 Ceske Budejovice (Czech Republic); Prochazkova, Jitka [Global Change Research Institute, CAS, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic); Stepanek, Miroslav; Hajduova, Jana [Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, Hlavova 2030, 128 40 Prague 2 (Czech Republic); Pospiskova, Kristyna [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 27, 783 71 Olomouc (Czech Republic); Safarikova, Mirka [Global Change Research Institute, CAS, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic); Department of Nanobiotechnology, Biology Centre, CAS, ISB, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic); Safarik, Ivo [Global Change Research Institute, CAS, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic); Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 27, 783 71 Olomouc (Czech Republic); Department of Nanobiotechnology, Biology Centre, CAS, ISB, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic)

    2017-04-01

    A simple, one-pot process for the preparation of magnetically responsive yeast-based biocatalysts was developed. Saccharomyces cerevisiae, Candida utilis and Kluyveromyces lactis cells were successfully incorporated into chitosan gel magnetically modified with poly(methacrylic acid)-stabilized magnetic fluid (PMAA-FF) during its formation. Magnetic PMAA-FF/chitosan/yeast composites were efficiently employed for invert sugar production. The dependence of invertase activity on used yeast, amount of magnetic biocatalyst, agitation time and after reuse was studied in detail. The tested magnetic biocatalysts retained at least 69% of their initial activity after 8 reuse cycles. - Highlights: • New types of magnetically responsive yeast biocomposites were prepared. • Recently developed PMAA-stabilized magnetic fluid was used. • Three yeast species were entrapped into magnetic chitosan gel during its formation. • All biocatalysts were efficiently employed for invert sugar formation.

  16. Review of antimicrobial and antioxidative activities of chitosans in food.

    Science.gov (United States)

    Friedman, Mendel; Juneja, Vijay K

    2010-09-01

    Interest in chitosan, a biodegradable, nontoxic, non-antigenic, and biocompatible biopolymer isolated from shellfish, arises from the fact that chitosans are reported to exhibit numerous health-related beneficial effects, including strong antimicrobial and antioxidative activities in foods. The extraordinary interest in the chemistry and application in agriculture, horticulture, environmental science, industry, microbiology, and medicine is attested by about 17,000 citations on this subject in the Scopus database. A special need exists to develop a better understanding of the role of chitosans in ameliorating foodborne illness. To contribute to this effort, this overview surveys and interprets our present knowledge of the chemistry and antimicrobial activities of chitosan in solution, as powders, and in edible films and coating against foodborne pathogens, spoilage bacteria, and pathogenic viruses and fungi in several food categories. These include produce, fruit juices, eggs and dairy, cereal, meat, and seafood products. Also covered are antimicrobial activities of chemically modified and nanochitosans, therapeutic properties, and possible mechanisms of the antimicrobial, antioxidative, and metal chelating effects. Further research is suggested in each of these categories. The widely scattered data on the multifaceted aspects of chitosan microbiology, summarized in the text and in 10 tables and 8 representative figures, suggest that low-molecular-weight chitosans at a pH below 6.0 presents optimal conditions for achieving desirable antimicrobial and antioxidative-preservative effects in liquid and solid foods. We are very hopeful that the described findings will be a valuable record and resource for further progress to improve microbial food safety and food quality.

  17. 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

  18. Biocompatibility assessment of porous chitosan-Nafion and chitosan-PTFE composites in vivo.

    Science.gov (United States)

    Liu, Bo-Ji; Ma, Li-Nan; Su, Juan; Jing, Wei-Wei; Wei, Min-Jie; Sha, Xian-Zheng

    2014-06-01

    Chitosan (CS) is widely used as a scaffold material in tissue engineering. The objective of this study was to test whether porous chitosan membrane (PCSM) coating for Nafion used in implantable sensor reduced fibrous capsule (FC) density and promoted superior vascularization compared with PCSM coating for polytetrafluoroethylene (PTFE). PCSM was fabricated with solvent casting/particulate leaching method using silica gel as porogen and characterized in vitro. Then, PCSM-Nafion and PCSM-PTFE composites were assembled with hydrated PCSM and implanted subcutaneously in rats. The histological analysis was performed in comparison with Nafion and PTFE. Implants were explanted 35, 65, and 100 days after the implantation. Histological assessments indicated that both composites achieved presumed effects of porous coatings on decreasing collagen deposition and promoting angiogenesis. PCSM-PTFE exerted higher collagen deposition by area ratio, both within and outside, compared with that of PCSM-Nafion. Angiogenesis within and outside the PCSM-Nafion both increased over time, but that of the PCSM-PTFE within decreased. Copyright © 2013 Wiley Periodicals, Inc.

  19. Design of a potentially prebiotic and responsive encapsulation material for probiotic bacteria based on chitosan and sulfated β-glucan

    DEFF Research Database (Denmark)

    Yücel, Cigdem; Sotres, Javier; Rascón, Ana

    2017-01-01

    HYPOTHESIS: Chitosan and sulfated oat β-glucan are materials suitable to create a prebiotic coating for targeted delivery to gastrointestinal system, using the layer by layer technology. EXPERIMENT: Quartz crystal microbalance with dissipation (QCM-D), spectroscopic ellipsometry (SE) and atomic...... force microscopy (AFM) were used to assess the multilayer formation capacity and characterize the resulting coatings in terms of morphology and material properties such as structure and rigidity. The coating of colloidal materials was proven, specifically on L. acidophilus bacteria as measured...

  20. Chitosan-based films composites for wound healing purposes

    International Nuclear Information System (INIS)

    Alves, Natali de O.; Silva, Gabriela T. da; Schulz, Gracelie A.S.; Fajardo, Andre R.

    2015-01-01

    Chitosan has been extensively applied in the developing of biomaterials due to its desirable good physico-chemical and biological properties. According to this, here films composite of chitosan, poly(vinyl alcohol) and bovine bone powder were prepared by casting willing to be applied in wound healing purposes. Moreover, the first step was the developing of a suitable method to obtain bovine bone powder, which was utilized here as filler. All the materials and films were fully characterized by FTIR, DRX and thermal analysis. Water uptake capacity was measured by swelling assays. (author)

  1. Molecularly Imprinted Polymers Chitosan-Glutaraldehyde for Monosodium Glutamate

    Science.gov (United States)

    Mulyasuryani, Ani; Haryanto, Edi; Sulistyarti, Hermin; Rumhayati, Barlah

    2018-01-01

    Chitosan has been used as a functional monomer in the synthesis of molecularly imprinted polymers (MIP) for monosodium glutamate (MSG). MIP is made from a mixture of 5 g chitosan, 50 mg glutaraldehyde and 2 g MSG, MIP is formed as flakes and beads. MIPs are identified by the FTIR spectrum, SEM image and their adsorption capabilities. MIP flakes and beads have no structural differences if they are based on FTIR or SEM spectra, but MIP adsorption capacity of beads higher than flakes. Adsorption capacity of MIP flakes is 548 mg/g and MIP beads 627 mg/g.

  2. Production and characterization of chitosan obtained from shrimp exoskeleton

    International Nuclear Information System (INIS)

    Almeida, Leticia P.; Aguiar, Nayara V.; Rodrigues, Willias da L.; Silva, Rafael S. da; Moreira, Carly K.P.

    2015-01-01

    Chitosan is a natural polymer, biocompatible, biodegradable and non-toxic. It's derived from the deacetylation of chitin, which constitutes the most part of the exoskeleton of insects, crustaceans and fungal cell wall. After cellulose, chitin is more organic compound found in nature. The Chitin was separated from others components of shrimp waste (Macrobrachium amazonicum) by a chemical process that involves three steps: demineralization, deproteination and depigmentation. The chitosan produced was characterized by potentiometric titration, to find the degree of deacetylation (85,32 %), determining the intrinsic viscosity to define its molecular weight (503.223 g/mol), and X-ray diffraction to determine its crystallinity index (58,4 %). (author)

  3. Rheological study of chitosan and its blends: An overview

    Directory of Open Access Journals (Sweden)

    Esam A. El-hefian

    2010-06-01

    Full Text Available Chitosan, a modified natural carbohydrate polymer derived from carapaces of crabs and shrimps, has received a great deal of attention for its applications in diverse fields owing to its biodegradability, biocompatibility, non-toxicity and anti-bacterial property. The wide-ranging applications involve a broad spectrum of characterisation techniques and rheology represents one technique of growing importance in this field. This paper is an attempt to review the latest development in the rheology of chitosan, either on its own or associated with other materials, including the parameters that strongly influence its rheological behaviour such as concentration, pH and temperature.

  4. Dynamic removal of uranium by chitosan: influence of operating parameters

    International Nuclear Information System (INIS)

    Jansson-Charrier, Marielle; Guibal, Eric; Roussy, Jean; Surjous, Robert; Le Cloirec, Pierre

    1996-01-01

    New wastewater treatments involving biosorption processes are being developed. This work focuses on the dynamic removal of uranium using chitosan in fixed-bed reactors and investigates the main operating parameters: particle size, column size, flow velocity and metal ion concentrations. The results confirm the predominant effect of diffusion on the control rate. The optimization of the process should take into account both sorption performances and hydrodynamic behaviour. The process is successfully applied to the treatment of leachates at an abandoned mine site. This study shows that chitosan is an effective sorbent for the treatment and recovery of uranium from dilute effluents. (Author)

  5. Chitosan and carboxymethyl-chitosan capping ligands: Effects on the nucleation and growth of hydroxyapatite nanoparticles for producing biocomposite membranes

    Energy Technology Data Exchange (ETDEWEB)

    Dumont, Vitor C.; Mansur, Alexandra A.P.; Carvalho, Sandhra M.; Medeiros Borsagli, Fernanda G.L.; Pereira, Marivalda M.; Mansur, Herman S., E-mail: hmansur@demet.ufmg.br

    2016-02-01

    Synthetic biomaterials based on calcium phosphates (CaP) have been widely studied for bone tissue reconstruction therapies, but no definitive solution that fulfills all of the required properties has been identified. Thus, this study reports the synthesis of composite membranes based on nanohydroxyapatite particles (nHA) embedded in chitosan (CHI) and O-carboxymethyl chitosan (CMC) matrices produced using a one-step co-precipitation method in water media. Biopolymers were used as capping ligands for simultaneously controlling the nucleation and growth of the nHA particles during the precipitation process and also to form the polymeric network of the biocomposites. The bionanocomposites were extensively characterized using light microscopy (LM), scanning and transmission electron microscopy (SEM/TEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), atomic force microscopy (AFM), X-ray micro-CT analysis (μCT), and MTT (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) cell proliferation assays for cell cytotoxicity. The results demonstrated that the ligands used during the synthesis highly affected the composites produced, primarily due the changes in the mechanisms and kinetics of nucleation and growth of the HA particles at the nanoscale level. The SEM images revealed that the use of carboxyl-functionalized chitosan (CMC) ligands significantly reduced the average size of the HA nanoparticles and caused the formation of a narrower size distribution (90 ± 20 nm) compared to the HA nanoparticles produced with chitosan ligands (220 ± 50 nm). The same trend was verified by the AFM analysis, where the nHA particles were formed evenly dispersed in the polymer matrix. However, the CMC-based composites were more homogeneously distributed, which was endorsed by the images collected via X-ray micro-CT. The FTIR spectra and the XRD analysis indicated that nanosized hydroxyapatite was the

  6. Fabrication of fluorescent chitosan-containing microcapsules

    Directory of Open Access Journals (Sweden)

    Zhang R.

    2013-08-01

    Full Text Available Intense emission peaks of Eu(DBM3Phen (DBM and Phen are dibenzoylmethane and 1,10-phenanthroline, respectively in the microcapsules containing molecules of quaternary ammonium chitosan (QACS and sodium alginate are observed. The microcapsules are assembled by using CaCO3 particles as template cores by the layer-by-layer (LbL technique. Observation of microcapsules by the fluorescence mode and the transmission mode in the confocal laser scanning microscopy shows that the microcapsules are intact after core decomposition. Fluorescence under ultraviolet irradiation comes directly from the Eu(DBM3Phen. Homogeneous assembly of Eu(DBM3Phen can be deduced due to the homogeneous fluorescence of the microcapsules in the fluorescence micrographs. The microcapsules show adherence to solid substrates due to large quantities of hydroxyl groups of QACS. AFM measurements of dried hollow microcapsules with only 4 bilayers of (CS/SA fabricated with Eu(DBM3Phen show the intact shell with a thickness of 3.0 nm. Regarding the biocompatible natural polysaccharides and the intense fluorescence emission, the microcapsules in this work might be of great importance in potential application in drug delivery and bioassay.

  7. Characterization​ and ​analysis of ​m​otion ​m​echanism​ of electroactive​ chitosan-based actuator.

    Science.gov (United States)

    Altınkaya, Emine; Seki, Yoldaş; Çetin, Levent; Gürses, Barış Oğuz; Özdemir, Okan; Sever, Kutlay; Sarıkanat, Mehmet

    2018-02-01

    In order to analyze the bending mechanism of the electroactive​ chitosan-based actuator, different amounts of poly(diallyldimethylammonium chloride) (PDAD) were incorporated in chitosan solution. The effects of PDAD concentration on electromechanical performance of chitosan actuator were investigated under various excitation voltages. With the incorporation of PDAD into chitosan solution, crosslinked chitosan film acts as an actuator showing a considerable displacement behavior. However it can be noted that higher incorporation of PDAD into chitosan solution decreased the performance of the actuators. Thermal, viscoelastic, and crystallographic properties of the chitosan films were examined by thermogravimetric analysis, dynamic mechanical analysis, and X-ray diffraction analysis, respectively. The effect of incorporation of PDAD in chitosan-based film on morphological properties of chitosan film was determined by scanning electron microscopy. It was observed that the films involving PDAD have larger pore size than the PDAD free film. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. The functional properties of chitosan-glucose-asparagine Maillard reaction products and mitigation of acrylamide formation by chitosans.

    Science.gov (United States)

    Sung, Wen-Chieh; Chang, Yu-Wei; Chou, Yu-Hao; Hsiao, Hsin-I

    2018-03-15

    This research aims to clarify the interactions that occur in a food model system consisting of glucose, asparagine and chitosans. Low molecular weight chitosan exerted a potent inhibitory effect (46.8%) on acrylamide and Maillard reaction products (MRPs) (>52.6%), respectively. Compared to a previous study conducted using the fructose system, the novel findings of this research demonstrate that the formation of acrylamide and Maillard reaction products was lower with glucose than with fructose when they were used as reducing sugars in food model systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Lipase entrapment in PVA/Chitosan biodegradable film for reactor coatings

    Energy Technology Data Exchange (ETDEWEB)

    Batista, Karla A. [Departamento de Bioquímica e Biologia Molecular, Laboratório de Química de Proteínas, Universidade Federal de Goiás, Cx. Postal 131, 74001-970, Goiânia, GO (Brazil); Lopes, Flavio Marques [Departamento de Bioquímica e Biologia Molecular, Laboratório de Química de Proteínas, Universidade Federal de Goiás, Cx. Postal 131, 74001-970, Goiânia, GO (Brazil); Unidade Universitária de Ciências Exatas e Tecnológicas, Universidade Estadual de Goiás, Anápolis, GO (Brazil); Yamashita, Fabio [Departamento de Tecnologia de Alimentos e Medicamentos, Laboratório de Tecnologia, Universidade Estadual de Londrina, Cx. Postal 6001, CEP 86051-990, Londrina, PR (Brazil); Fernandes, Kátia Flávia, E-mail: katia@icb.ufg.br [Departamento de Bioquímica e Biologia Molecular, Laboratório de Química de Proteínas, Universidade Federal de Goiás, Cx. Postal 131, 74001-970, Goiânia, GO (Brazil)

    2013-04-01

    This study reports the development and characterization of novel biodegradable film, based on chitosan and polyvinyl alcohol containing lipase entrapped. The films showed a thickness of 70.4 and 79 μm to PVA/Chitosan and PVA/Chitosan/Lipase, respectively. The entrapment of lipase in PVA/Chitosan film resulted in increasing of 69.4% tensile strength (TS), and 52.4% of elongation. SEM images showed the formation of a continuous film, without pores or cracks. The lipase entrapment efficiency was estimated in 92% and the films were repeatedly used for 25 hydrolytic cycles, maintaining 62% of initial activity. The PVA/Chitosan/Lipase film was used for olive oil hydrolysis of high performance. These results indicate that PVA/Chitosan/Lipase is a promising material for biotechnology applications such as triacylglycerol hydrolysis and biodiesel production. - Highlights: ► Development and characterization of PVA/Chitosan biodegradable film ► Lipase immobilization onto PVA/Chitosan film ► PVA/Chitosan/Lipase film for reactor coating ► Olive oil hydrolysis using PVA/Chitosan/Lipase film.

  10. Adsorption of chitosan onto carbonaceous surfaces and its application: atomic force microscopy study

    International Nuclear Information System (INIS)

    Tan Shengnan; Liu Zhiguo; Zu Yuangang; Fu Yujie; Xing Zhimin; Zhao Lin; Sun Tongze; Zhou Zhen

    2011-01-01

    The adsorption of chitosan onto highly ordered pyrolytic graphite(HOPG) surfaces and its applications have been studied by atomic force microscopy (AFM). The results indicated that chitosan topography formed on the HOPG surface significantly depends on the pH conditions and its concentration for the incubation. Under strongly acidic conditions (pH -1 , chitosan formed into uniform network structures composed of fine chains. When the solution pH was changed from 3.5 to 6.5, chitosan tends to form a thicker film. Under neutral and basic conditions, chitosan changed into spherical nanoparticles, and their sizes were increased with increasing pH. Dendritic structures have been observed when the chitosan concentration was increased up to 5 mg ml -1 . In addition, the chitosan topography can also be influenced by ionic strength and the addition of different metal ions. When 0.1 M metal ions Na + , Mg 2+ , Ca 2+ and Cu 2+ were added into the chitosan solution at pH 3.0 for the incubation, network structures, branched chains, block structures and dense networks attached with many small particles were observed, respectively. The potential applications of these chitosan structures on HOPG have been explored. Preliminary results characterized by AFM and XPS indicated that the chitosan network formed on the HOPG surface can be used for AFM lithography, selective adsorption of gold nanoparticles and DNA molecules.

  11. Synthesis, characterization, bioactivity and potential application of phenolic acid grafted chitosan: A review.

    Science.gov (United States)

    Liu, Jun; Pu, Huimin; Liu, Shuang; Kan, Juan; Jin, Changhai

    2017-10-15

    In recent years, increasing attention has been paid to the grafting of phenolic acid onto chitosan in order to enhance the bioactivity and widen the application of chitosan. Here, we present a comprehensive overview on the recent advances of phenolic acid grafted chitosan (phenolic acid-g-chitosan) in many aspects, including the synthetic method, structural characterization, biological activity, physicochemical property and potential application. In general, four kinds of techniques including carbodiimide based coupling, enzyme catalyzed grafting, free radical mediated grafting and electrochemical methods are frequently used for the synthesis of phenolic acid-g-chitosan. The structural characterization of phenolic acid-g-chitosan can be determined by several instrumental methods. The physicochemical properties of chitosan are greatly altered after grafting. As compared with chitosan, phenolic acid-g-chitosan exhibits enhanced antioxidant, antimicrobial, antitumor, anti-allergic, anti-inflammatory, anti-diabetic and acetylcholinesterase inhibitory activities. Notably, phenolic acid-g-chitosan shows potential applications in many fields as coating agent, packing material, encapsulation agent and bioadsorbent. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Effects of chitosan inhibitor on the electrochemical corrosion behavior of 2205 duplex stainless steel

    Science.gov (United States)

    Yang, Se-fei; Wen, Ying; Yi, Pan; Xiao, Kui; Dong, Chao-fang

    2017-11-01

    The effects of chitosan inhibitor on the corrosion behavior of 2205 duplex stainless steel were studied by electrochemical measurements, immersion tests, and stereology microscopy. The influences of immersion time, temperature, and chitosan concentration on the corrosion inhibition performance of chitosan were investigated. The optimum parameters of water-soluble chitosan on the corrosion inhibition performance of 2205 duplex stainless steel were also determined. The water-soluble chitosan showed excellent corrosion inhibition performance on the 2205 duplex stainless steel. Polarization curves demonstrated that chitosan acted as a mixed-type inhibitor. When the stainless steel specimen was immersed in the 0.2 g/L chitosan solution for 4 h, a dense and uniform adsorption film covered the sample surface and the inhibition efficiency (IE) reached its maximum value. Moreover, temperature was found to strongly influence the corrosion inhibition of chitosan; the inhibition efficiency gradually decreased with increasing temperature. The 2205 duplex stainless steel specimen immersed in 0.4 g/L water-soluble chitosan at 30°C displayed the best corrosion inhibition among the investigated specimens. Moreover, chitosan decreased the corrosion rate of the 2205 duplex stainless steel in an FeCl3 solution.

  13. Fabrication and Characteristics of Chitosan Sponge as a Tissue Engineering Scaffold

    Directory of Open Access Journals (Sweden)

    Takeshi Ikeda

    2014-01-01

    Full Text Available Cells, growth factors, and scaffolds are the three main factors required to create a tissue-engineered construct. After the appearance of bovine spongiform encephalopathy (BSE, considerable attention has therefore been focused on nonbovine materials. In this study, we examined the properties of a chitosan porous scaffold. A porous chitosan sponge was prepared by the controlled freezing and lyophilization of different concentrations of chitosan solutions. The materials were examined by scanning electron microscopy, and the porosity, tensile strength, and basic fibroblast growth factor (bFGF release profiles from chitosan sponge were examined in vitro. The morphology of the chitosan scaffolds presented a typical microporous structure, with the pore size ranging from 50 to 200 μm. The porosity of chitosan scaffolds with different concentrations was approximately 75–85%. A decreasing tendency for porosity was observed as the concentration of the chitosan increased. The relationship between the tensile properties and chitosan concentration indicated that the ultimate tensile strength for the sponge increased with a higher concentration. The in vitro bFGF release study showed that the higher the concentration of chitosan solution became, the longer the releasing time of the bFGF from the chitosan sponge was.

  14. Hydrophobization and antimicrobial activity of chitosan and paper-based packaging material.

    Science.gov (United States)

    Bordenave, Nicolas; Grelier, Stephane; Coma, Veronique

    2010-01-11

    This study reports the elaboration of water-resistant, antimicrobial, chitosan and paper-based materials as environmentally friendly food packaging materials. Two types of papers were coated with chitosan-palmitic acid emulsions or with a blend of chitosan and O,O'-dipalmitoylchitosan (DPCT). Micromorphology studies showed that inclusion of hydrophobic compounds into the chitosan matrix was enhanced by grafting them onto chitosan and that this led to their penetration of the paper's core. Compared to chitosan-coated papers, the coating of chitosan-palmitic emulsion kept vapor-barrier properties unchanged (239 and 170 g.m(-2).d(-1) versus 241 and 161 g.m(-2).d(-1)), while the coating of chitosan-DPCT emulsion dramatically deteriorated them (441 and 442 g.m(-2).d(-1)). However, contact angle measurements (110-120 degrees after 1 min) and penetration dynamics analysis showed that both strategies improved liquid-water resistance of the materials. Kit-test showed that all hydrophobized chitosan-coated papers kept good grease barrier properties (degree of resistance 6-8/12). Finally, all chitosan-coated materials exhibited over 98% inhibition on Salmonella Typhimurium and Listeria monocytogenes .

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

    Science.gov (United States)

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

    2014-01-01

    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. Fe3O4 was synthesized and optimized as magnetic core nanoparticles and then chitosan covered this magnetic core. The size and morphology of the nano-magnetic chitosan was analyzed by scanning electron microscope (SEM). Topography and size distribution of the nanoparticles were shown with two-dimensional and three-dimensional images of atomic force microscopy (AFM). The nanoparticles were analyzed using transmission electron microscopy (TEM). The chitosan nanoparticles prepared in the experiment exhibited white powder shape. The SEM micrographs of the nano-magnetic chitosan showed that they were approximately uniform spheres. The unmodified chitosan nanoparticles composed of clusters of nanoparticles with sizes ranging from 10 nm to 80 nm. AFM provides a three-dimensional surface profile. The TEM image showed physical aggregation of the chitosan nanoparticles. The results show that a novel chitosan nanoparticle was successfully synthesized and characterized. It seems that this nanoparticle like the other chitosan nano particles has potential applications for nanomedicine, biomedical engineering, industrial and pharmaceutical fields.

  16. Novel procedure to enhance PLA surface properties by chitosan irreversible immobilization

    Science.gov (United States)

    Stoleru, Elena; Dumitriu, Raluca Petronela; Munteanu, Bogdanel Silvestru; Zaharescu, Traian; Tănase, Elisabeta Elena; Mitelut, Amalia; Ailiesei, Gabriela-Liliana; Vasile, Cornelia

    2016-03-01

    A novel two step procedure was applied for poly(lactic acid) (PLA) functionalization consisting in the exposure to cold radiofrequency plasma in nitrogen atmosphere or to gamma irradiation followed by ;grafting to; of a chitosan layer using carbodiimide chemistry. The adhesion and stability of the deposited surface layer was assured by plasma/gamma irradiation treatment while the chitosan layer offers antifungal/antibacterial/antioxidant activities. Chitosan with different viscosities/deacetylation degree was deposited by electrospinning or immersion methods. Correlations between rheological behavior of chitosan solutions and chitosan layer deposition conditions are made. The PLA surface properties were investigated by water contact angle measurements, ATR-FTIR spectroscopy, AFM, chemiluminiscence, etc. It has been established that the surface roughness increases direct proportional with cold plasma duration and gamma irradiation dose and further increases by chitosan coating which at its turn depends on chitosan characteristics (viscosity and deacetylation degree) and method of deposition. Nano-fibers with relatively homogeneous and reproducible features are obtained by electrospinning of highly viscous chitosan while with the other two types of chitosan both microparticles and nano-fibers are formed. The chitosan coating obtained by immersion is more homogenous and compact and has a better antibacterial activity than the electrospun layer as fiber meshes.

  17. Binding Cellulose and Chitosan via Intermolecular Inclusion Interaction: Synthesis and Characterisation of Gel

    Directory of Open Access Journals (Sweden)

    Jiufang Duan

    2015-01-01

    Full Text Available A novel cellulose-chitosan gel was successfully prepared in three steps: (1 ferrocene- (Fc- cellulose with degrees of substitution (DS of 0.5 wt% was synthesised by ferrocenecarboxylic acid and cellulose within dimethylacetamide/lithium chloride (DMAc/LiCl; (2 the β-cyclodextrin (β-CD groups were introduced onto the chitosan chains by reacting chitosan with epichlorohydrin in dimethyl sulphoxide and a DS of 0.35 wt%; (3 thus, the cellulose-chitosan gel was obtained via an intermolecular inclusion interaction of Fc-cellulose and β-CD-chitosan in DMA/LiCl, that is, by an intermolecular inclusion interaction, between the Fc groups of cellulose and the β-CD groups on the chitosan backbone at room temperature. The successful synthesis of Fc-cellulose and β-CD-chitosan was characterised by 13C-NMR spectroscopy. The gel based on β-CD-chitosan and Fc-cellulose was formed under mild conditions which can engender autonomous healing between cut surfaces after 24 hours: the gel cannot self-heal while the cut surfaces were coated with a solution of a competitive guest (adamantane acid. The cellulose-chitosan complex made by this method underwent self-healing. Therefore, this study provided a novel method of expanding the application of chitosan by binding it with another polymer.

  18. Lipase entrapment in PVA/Chitosan biodegradable film for reactor coatings

    International Nuclear Information System (INIS)

    Batista, Karla A.; Lopes, Flavio Marques; Yamashita, Fabio; Fernandes, Kátia Flávia

    2013-01-01

    This study reports the development and characterization of novel biodegradable film, based on chitosan and polyvinyl alcohol containing lipase entrapped. The films showed a thickness of 70.4 and 79 μm to PVA/Chitosan and PVA/Chitosan/Lipase, respectively. The entrapment of lipase in PVA/Chitosan film resulted in increasing of 69.4% tensile strength (TS), and 52.4% of elongation. SEM images showed the formation of a continuous film, without pores or cracks. The lipase entrapment efficiency was estimated in 92% and the films were repeatedly used for 25 hydrolytic cycles, maintaining 62% of initial activity. The PVA/Chitosan/Lipase film was used for olive oil hydrolysis of high performance. These results indicate that PVA/Chitosan/Lipase is a promising material for biotechnology applications such as triacylglycerol hydrolysis and biodiesel production. - Highlights: ► Development and characterization of PVA/Chitosan biodegradable film ► Lipase immobilization onto PVA/Chitosan film ► PVA/Chitosan/Lipase film for reactor coating ► Olive oil hydrolysis using PVA/Chitosan/Lipase film

  19. A healing method of tympanic membrane perforations using three-dimensional porous chitosan scaffolds.

    Science.gov (United States)

    Kim, Jangho; Kim, Seung Won; Choi, Seong Jun; Lim, Ki Taek; Lee, Jong Bin; Seonwoo, Hoon; Choung, Pill-Hoon; Park, Keehyun; Cho, Chong-Su; Choung, Yun-Hoon; Chung, Jong Hoon

    2011-11-01

    Both surgical tympanoplasty and paper patch grafts are frequently procedured to heal tympanic membrane (TM) perforation or chronic otitis media, despite their many disadvantages. In this study, we report a new healing method of TM perforation by using three-dimensional (3D) porous chitosan scaffolds (3D chitosan scaffolds) as an alternative method to surgical treatment or paper patch graft. Various 3D chitosan scaffolds were prepared; and the structural characteristics, mechanical property, in vitro biocompatibility, and healing effects of the 3D chitosan scaffolds as an artificial TM in in vivo animal studies were investigated. A 3D chitosan scaffold of 5 wt.% chitosan concentration showed good proliferation of TM cells in an in vitro study, as well as suitable structural characteristics and mechanical property, as compared with either 1% or 3% chitosan. In in vivo animal studies, 3D chitosan scaffold were able to migrate through the pores and surfaces of TM cells, thus leading to more effective TM regeneration than paper patch technique. Histological observations demonstrated that the regenerated TM with the 3D chitosan scaffold consisted of three (epidermal, connective tissue, and mucosal) layers and were thicker than normal TMs. The 3D chitosan scaffold technique may be an optimal healing method used in lieu of surgical tympanoplasty in certain cases to heal perforated TMs.

  20. Chitosan-Coated Collagen Membranes Promote Chondrocyte Adhesion, Growth, and Interleukin-6 Secretion

    Directory of Open Access Journals (Sweden)

    Nabila Mighri

    2015-11-01

    Full Text Available Designing scaffolds made from natural polymers may be highly attractive for tissue engineering strategies. We sought to produce and characterize chitosan-coated collagen membranes and to assess their efficacy in promoting chondrocyte adhesion, growth, and cytokine secretion. Porous collagen membranes were placed in chitosan solutions then crosslinked with glutaraldehyde vapor. Fourier transform infrared (FTIR analyses showed elevated absorption at 1655 cm-1 of the carbon–nitrogen (N=C bonds formed by the reaction between the (NH2 of the chitosan and the (C=O of the glutaraldehyde. A significant peak in the amide II region revealed a significant deacetylation of the chitosan. Scanning electron microscopy (SEM images of the chitosan-coated membranes exhibited surface variations, with pore size ranging from 20 to 50 µm. X-ray photoelectron spectroscopy (XPS revealed a decreased C–C groups and an increased C–N/C–O groups due to the reaction between the carbon from the collagen and the NH2 from the chitosan. Increased rigidity of these membranes was also observed when comparing the chitosan-coated and uncoated membranes at dried conditions. However, under wet conditions, the chitosan coated collagen membranes showed lower rigidity as compared to dried conditions. Of great interest, the glutaraldehyde-crosslinked chitosan-coated collagen membranes promoted chondrocyte adhesion, growth, and interleukin (IL-6 secretion. Overall results confirm the feasibility of using designed chitosan-coated collagen membranes in future applications, such as cartilage repair.

  1. Preparation of curcumin-loaded pluronic F127/chitosan nanoparticles for cancer therapy

    International Nuclear Information System (INIS)

    Phuc Le, Thi Minh; Pham, Van Phuc; Lua Dang, Thi Minh; Huyen La, Thi; Le, Thi Hanh; Le, Quang Huan

    2013-01-01

    Nanoparticles (NPs) have been proven to be an effective delivery system with few side effects for anticancer drugs. In this study, curcumin-loaded NPs have been prepared by an ionic gelation method using chitosan (Chi) and pluronic ® F-127 (PF) as carriers to deliver curcumin to the target cancer cells. Prepared NPs were characterized using Zetasizer, fluorescence microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Our results showed that the encapsulation efficiency of curcumin was approximately 50%. The average size of curcumin-loaded PF/Chi NPs was 150.9 nm, while the zeta potential was 5.09 mV. Cellular uptake of curcumin-loaded NPs into HEK293 cells was confirmed by fluorescence microscopy. (paper)

  2. Scaffold of chitosan-sodium alginate and hydroxyapatite with application potential for bone regeneration

    International Nuclear Information System (INIS)

    Rebelo, Marcia de A.; Alves, Thais F.R.; Lopes, Francielly C.C.N; Oliveira Junior, Jose Martins de; Pontes, Katiusca S.; Fogaca, Bruna A.C.; Chaud, Marco V.

    2015-01-01

    Scaffold for organic tissue regeneration are architectural, three-dimensional, porous, biocompatible and biodegradable devices. The first challenges to be met in the development of these devices to mimic the biomechanical properties of the target tissue. The aim of this study was to develop and to characterize scaffolds composed of chitosan (Ch), sodium alginate (SA), hydroxyapatite (HA). The scaffolds were obtained by lyophilization. HA has been incorporated into the polymer dispersion in Ch-AS concentration of 20 and 60%. The mechanical properties of the scaffold were determined by tensile and compression tests. Swelling capacity was assessed in the presence of simulated saliva, purified water, HCl 0.01M, NaOH 0.01M. The calcium content was quantified using fluorescence X-rays. Analysis of the results indicates that the Qt-AS-HA-60% scaffold obtained by lyophilization meets promising properties for bone tissue regeneration. (author)

  3. Curcumin drug delivery by vanillin-chitosan coated with calcium ferrite hybrid nanoparticles as carrier.

    Science.gov (United States)

    Kamaraj, Sriram; Palanisamy, Uma Maheswari; Kadhar Mohamed, Meera Sheriffa Begum; Gangasalam, Arthanareeswaran; Maria, Gover Antoniraj; Kandasamy, Ruckmani

    2018-04-30

    The aim of the present investigation is the development, optimization and characterization of curcumin-loaded hybrid nanoparticles of vanillin-chitosan coated with super paramagnetic calcium ferrite. The functionally modified vanillin-chitosan was prepared by the Schiff base reaction to enhance the hydrophobic drug encapsulation efficiency. Calcium ferrite (CFNP) nano particles were added to the vanillin modified chitosan to improve the biocompatibility. The vanillin-chitosan-CFNP, hybrid nanoparticle carrier was obtained by ionic gelation method. Characterizations of the hybrid materials were performed by XRD, FTIR, 1 H NMR, TGA, AFM and SEM techniques to ensure the modifications on the chitosan material. Taguchi method was applied to optimize the drug (curcumin) encapsulation efficiency by varying the drug to chitosan-vanillin, CFNP to chitosan-vanillin and TPP (sodium tripolyphospate) to chitosan-vanillin ratios. The maximum encapsulation efficiency was obtained as 98.3% under the conditions of 0.1, 0.75 and 1.0 for the drug to chitosan-vanillin, CFNP to chitosan-vanillin and TPP to chitosan-vanillin ratios, respectively. The curcumin release was performed at various pH, initial drug loading concentrations and magnetic fields. The drug release mechanism was predicted by fitting the experimental kinetic data with various drug release models. The drug release profiles showed the best fit with Higuchi model under the most of conditions. The drug release mechanism followed both non-Fickian diffusion and case II transport mechanism for chitosan, however the non-Fickian diffusion mechanism was followed for the vanillin modified chitosan. The biocompatibility of the hybrid material was tested using L929 fibroblast cells. The cytotoxicity test was performed against MCF-7 breast cancer cell line to check the anticancer property of the hybrid nano carrier with the curcumin drug. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Utilization of chitosan as an antimicrobial agent for pasteurized palm sap (Borassus flabellifer Linn.) during storage.

    Science.gov (United States)

    Naknean, Phisut; Jutasukosol, Keawta; Mankit, Theerarat

    2015-02-01

    The objective of this research was to assess the potential of chitosan for improvement the quality of pasteurized palm sap during storage. First, the effect of chitosan content on sensory attributes was investigated to select suitable concentration of chitosan for further study. Fresh palm sap was enriched with chitosan at various concentrations (0-2 g/L) and pasteurized at 80 °C for 10 min, consequently evaluated by consumers. It was found that samples added chitosan in the range of 0-1.00 g/L were considered acceptable. Thus, the addition chitosan in the concentration of 0-1.00 g/L was chosen for further study. The sample without chitosan addition was used as a control sample. Each selected sample was determined for their qualities during storage at 1 week interval. It was found that lightness and transmittance values of all samples tended to increase during storage. Lower PPO and invertase activity were observed in all chitosan-treated samples compared to control sample. Chitosan could minimize the loss of sucrose and the increase in glucose and fructose content during storage. In addition, an increase in chitosan concentration resulted in the increase in DPPH radical scavenging activity. Furthermore, the addition of chitosan could retard the development of microorganism during storage as demonstrated by lower microbial loads compared to control sample. It can be concluded that a combination of pasteurization with chitosan addition (0.50 g/L) and low temperature storage could preserve palm sap for approximately 6 weeks. Thus, the incorporation of chitosan in palm sap could be used as an alternative way to extend shelf life of pasteurized palm sap.

  5. Novel procedure to enhance PLA surface properties by chitosan irreversible immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Stoleru, Elena; Dumitriu, Raluca Petronela [Petru Poni Institute of Macromolecular Chemistry, Grigore Ghica Voda Alley, 41A, 700487 Iasi (Romania); Munteanu, Bogdanel Silvestru [“Al. I. Cuza” University, Faculty of Physics, 11 Carol I Blvd., 700506 Iasi (Romania); Zaharescu, Traian [INCDIE ICPE CA, Bucharest (Romania); Tănase, Elisabeta Elena; Mitelut, Amalia [Industrial Biotechnology Department, Faculty of Biotechnology – USAMV Bucharest (Romania); Ailiesei, Gabriela-Liliana [Petru Poni Institute of Macromolecular Chemistry, Grigore Ghica Voda Alley, 41A, 700487 Iasi (Romania); Vasile, Cornelia, E-mail: cvasile@icmpp.ro [Petru Poni Institute of Macromolecular Chemistry, Grigore Ghica Voda Alley, 41A, 700487 Iasi (Romania)

    2016-03-30

    Graphical abstract: - Highlights: • PLA requires functionalization prior to surface attaching chitosan. • Chitosan with different molecular weights was grafted onto PLA surface. • Antibacterial, antifungal, antioxidant PLA-based materials are obtained. • Nano-fibers coatings obtained by electrospinning of high molecular weight chitosan. - Abstract: A novel two step procedure was applied for poly(lactic acid) (PLA) functionalization consisting in the exposure to cold radiofrequency plasma in nitrogen atmosphere or to gamma irradiation followed by “grafting to” of a chitosan layer using carbodiimide chemistry. The adhesion and stability of the deposited surface layer was assured by plasma/gamma irradiation treatment while the chitosan layer offers antifungal/antibacterial/antioxidant activities. Chitosan with different viscosities/deacetylation degree was deposited by electrospinning or immersion methods. Correlations between rheological behavior of chitosan solutions and chitosan layer deposition conditions are made. The PLA surface properties were investigated by water contact angle measurements, ATR-FTIR spectroscopy, AFM, chemiluminiscence, etc. It has been established that the surface roughness increases direct proportional with cold plasma duration and gamma irradiation dose and further increases by chitosan coating which at its turn depends on chitosan characteristics (viscosity and deacetylation degree) and method of deposition. Nano-fibers with relatively homogeneous and reproducible features are obtained by electrospinning of highly viscous chitosan while with the other two types of chitosan both microparticles and nano-fibers are formed. The chitosan coating obtained by immersion is more homogenous and compact and has a better antibacterial activity than the electrospun layer as fiber meshes.

  6. Preparation and characterization of nano-hydroxyapatite within chitosan matrix

    International Nuclear Information System (INIS)

    Rogina, A.; Ivanković, M.; Ivanković, H.

    2013-01-01

    Nano-composites that show some features of natural bone both in composition and in microstructure have been prepared by in situ precipitation method. Apatite phase has been prepared from cost-effective precursors (calcite and urea phosphate) within chitosan (CS) matrix dissolved in aqueous acetic acid solution. The compositional and morphological properties of composites were studied by means of Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) thermogravimetric analysis (TGA) and transmission electron microscopy (TEM). Depending on the reaction conditions (temperature, reaction time, glucose addition and pH control) in addition to hydroxyapatite (HA) as a major phase, octacalcium hydrogen phosphate pentahydrate (OCP) and dicalcium phosphate anhydrate (DCPD) were formed as shown by XRD and FTIR. Crystallite lengths of precipitated HA estimated by Scherrer's equation were between 20 and 30 nm. A fibrous morphology (∼ 400 nm) of HA observed by TEM indicates that HA nucleates on chitosan chains. - Highlights: • Nano-hydroxyapatite (HA) was prepared by in situ precipitation within chitosan hydrogels and colloidal chitosan solution. • pH control was regulated by ammonia and urea degradation. • In situ urea degradation provides homogenous HA formation. • TEM imaging indicates fibrous morphology of HA with crystalline size of 400 nm. • Glucose addition and temperature variation affect inorganic phase formation

  7. Chitosan coating as an antibacterial surface for biomedical applications.

    Directory of Open Access Journals (Sweden)

    Mélanie D'Almeida

    Full Text Available A current public health issue is preventing post-surgical complications by designing antibacterial implants. To achieve this goal, in this study we evaluated the antibacterial activity of an animal-free chitosan grafted onto a titanium alloy.Animal-free chitosan binding on the substrate was performed by covalent link via a two-step process using TriEthoxySilylPropyl Succinic Anhydride (TESPSA as the coupling agent. All grafting steps were studied and validated by means of X-ray Photoelectron Spectroscopy (XPS, Time-of-Flight secondary ion mass spectrometry (ToF-SIMS analyses and Dynamic-mode Secondary Ion Mass Spectrometry (DSIMS. The antibacterial activity against Escherichia coli and Staphylococcus aureus strains of the developed coating was assessed using the number of colony forming units (CFU.XPS showed a significant increase in the C and N atomic percentages assigned to the presence of chitosan. A thick layer of polymer deposit was detected by ToF-SIMS and the results obtained by DSIMS measurements are in agreement with ToF-SIMS and XPS analyses and confirms that the coating synthesis was a success. The developed coating was active against both gram negative and gram positive tested bacteria.The success of the chitosan immobilization was proven using the surface characterization techniques applied in this study. The coating was found to be effective against Escherichia coli and Staphylococcus aureus strains.

  8. Influence of the drying method in chitosans purification step

    International Nuclear Information System (INIS)

    Fonseca, Ana C.M.; Batista, Jorge G.S.; Bettega, Antonio; Lima, Nelson B. de

    2015-01-01

    Currently, the study of extracellular biopolymers properties has received prominence for being easy extraction and purification. Chitosan has been an attractive proposition for applications in various fields such as engineering, biotechnology, medicine and pharmacology. For such applications, it is necessary purification of chitosan to obtain a product more concentrated and free of undesirable impurities. However, at this stage of the process of obtaining the biopolymer may occur morphological and physicochemical changes. This study evaluated the influence of the drying process after purification of a commercial chitosan sample and the importance of this step and its cost/benefit in applications requiring a high degree of purity. The method of drying influenced in the organoleptic properties and in the main characteristics of material. Analysis of the crystal structure by X-ray diffraction showed that the degree of crystallinity, X (%), in the purified chitosan samples was lower when compared with the unpurified sample. The degree of acetylation, DA (%), was analyzed by spectroscopy infrared with no significant changes on the three drying methods assessed, unlike the viscosimetric molecular weight, M_v, determined by capillary viscometry. (author)

  9. S-protected thiolated chitosan: synthesis and in vitro characterization.

    Science.gov (United States)

    Dünnhaupt, Sarah; Barthelmes, Jan; Thurner, Clemens C; Waldner, Claudia; Sakloetsakun, Duangkamon; Bernkop-Schnürch, Andreas

    2012-10-01

    Purpose of the present study was the generation and evaluation of novel thiolated chitosans, so-named S-protected thiolated chitosans as mucosal drug delivery systems. Stability of all conjugates concerning swelling and disintegration behavior as well as drug release was examined. Mucoadhesive properties were evaluated in vitro on intestinal mucosa. Different thiolated chitosans were generated displaying increasing amounts of attached free thiol groups on the polymer, whereby more than 50% of these thiol groups were linked with 6-mercaptonicotinamide. Based on the implementation of this hydrophobic residue, the swelling behavior was 2-fold decreased, whereas stability was essentially improved. Their mucoadhesive properties were 2- and 14-fold increased compared to corresponding thiolated and unmodified chitosans, respectively. Release studies out of matrix tablets comprising the novel conjugates revealed a controlled release of a model peptide. Accordingly, S-protected thiomers represent a promising type of mucoadhesive polymers for the development of various mucosal drug delivery systems. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Tailorable Trimethyl chitosans as adjuvant for intranasal immunization

    NARCIS (Netherlands)

    Verheul, R.J.

    2010-01-01

    Tailorable Trimethyl Chitosans as Adjuvant for Intranasal Immunization Active vaccination has proven to be the most (cost) effective tool in the fight against infectious diseases. Nowadays, most vaccines are administered via parenteral injection. However, the risk of contaminated needles and need

  11. Effects of dietary chitosan on growth performance and immune ...

    African Journals Online (AJOL)

    *

    2011-08-18

    Aug 18, 2011 ... relative to the body weight. Chitosan was provided by Golden-Shell. Biochemical Co., Ltd. Zhejiang, ... Soybean meal. 195. 150. Cottonseed meal. 20. 35. Rapeseed meal. 20. 35. Wheat bran. 100. 120. Fish meal. 25. 0. Rice bran. 53. Calcium carbonate. 6. 8.5. Calcium phosphate tribasic. 12. 7. Salt. 2. 2.5.

  12. Chitosan-gold-Lithium nanocomposites as solid polymer electrolyte.

    Science.gov (United States)

    Begum, S N Suraiya; Pandian, Ramanathaswamy; Aswal, Vinod K; Ramasamy, Radha Perumal

    2014-08-01

    Lithium micro batteries are emerging field of research. For environmental safety biodegradable films are preferred. Recently biodegradable polymers have gained wide application in the field of solid polymer electrolytes. To make biodegradable polymers films plasticizers are usually used. However, use of plasticizers has disadvantages such as inhomogenities in phases and mechanical instability that will affect the performance of Lithium micro batteries. We have in this research used gold nanoparticles that are environmentally friendly, instead of plasticizers. Gold nanoparticles were directly template upon chitosan membranes by reduction process so as to enhance the interactions of Lithium with the polymer. In this article, for the first time the characteristics of Chitosan-gold-Lithium nanocomposite films are investigated. The films were prepared using simple solution casting technique. We have used various characterization tools such as Small Angle Neutron Scattering (SANS), XRD, FTIR, Raman, FESEM, and AFM, Light scattering, Dielectric and electrical conductivity measurements. Our investigations show that incorporation of gold results in enhancement of conductivity in Lithium containing Chitosan films. Also it affects the dielectric characteristics of the films. We conclude through various characterization tools that the enhancement in the conductivity was due to the retardation of crystal growth of lithium salt in the presence of gold nanoparticles. A model is proposed regarding the formation of the new nanocomposite. The conductivity of these biodegradable films is comparable to those of the current inorganic Lithium micro batteries. This new chitosan-Au-Li nanocomposite has potential applications in the field of Lithium micro batteries.

  13. Enhancing mechanical properties of chitosan films via modification with vanillin.

    Science.gov (United States)

    Zhang, Zhi-Hong; Han, Zhong; Zeng, Xin-An; Xiong, Xia-Yu; Liu, Yu-Jia

    2015-11-01

    The vanillin/chitosan composite films were prepared using the solvent evaporation method. The properties of the films including optical property, water vapor permeability (WVP), tensile strength (TS) and elongation at break (%E) were studied to investigate the effect of cross-linking agent of vanillin on chitosan films by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectrum (FT-IR). Results showed that the TS of composite films increased by 53.3% and the WVP decreased by 36.5% compared with pure chitosan film that were due to the formation of the dense network structure by FT-IR spectra. There were almost no changes of the thermal stability of the composite films compared with the pure chitosan film by TGA analysis. In addition, from the SEM images, it could be seen that the film with addition of vanillin with 0.5-10% concentration exhibited good compatibility. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Supercritical fluid assisted production of chitosan oligomers micrometric powders.

    Science.gov (United States)

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

    2014-02-15

    Chitosan oligomers (O-chitosan) micrometric particles were produced from aqueous solution using a novel process, i.e. supercritical fluid assisted atomization introduced by hydrodynamic cavitation mixer (SAA-HCM). Hydrodynamic cavitation was introduced to enhance mass transfer and facilitate the mixing between SC-CO2 and liquid solution for fine particles formation. Well defined, separated and spherical microparticles were obtained, and the particles size could be well controlled with narrow distribution ranging from 0.5 μm to 3 μm. XRD patterns showed amorphous structure of O-chitosan microparticles. FTIR, TGA and DSC analyses confirmed that no change in molecular structure and thermal stability after SAA-HCM processing, while the water content was between 5.8% and 8.4%. Finally, tap densities were determined to be below 0.45 g/cm(3) indicating hollow or porous structures of microparticles. By tuning process parameters, theoretical mass median aerodynamic sizes lied inside respirable range of 1-2 μm, which presented the potential of the O-chitosan microparticles in application as inhaled dry powders. SAA-HCM was demonstrated to be very useful in particle size engineering. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Enzymatically biomineralized chitosan scaffolds for tissue-engineering applications.

    NARCIS (Netherlands)

    Dash, M.; Samal, S.K.; Douglas, T.E.L.; Schaubroeck, D.; Leeuwenburgh, S.C.G.; Voort, P. van der; Declercq, H.A.; Dubruel, P.

    2017-01-01

    Porous biodegradable scaffolds represent promising candidates for tissue-engineering applications because of their capability to be preseeded with cells. We report an uncrosslinked chitosan scaffold designed with the aim of inducing and supporting enzyme-mediated formation of apatite minerals in the

  16. Chitosan Cross-linked Reconstituted Amniotic Collagen Membrane ...

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Chitosan Cross-linked Reconstituted Amniotic Collagen Membrane – An Excellent Cell Substratum. The KERATINOCYTE proliferation and Differentiation into multiple layers is due to the presence of type - IV collagen in the amnion. Cultured FIBROBLASTS had good ...

  17. An Ionic Liquid Solution of Chitosan as Organocatalyst

    Directory of Open Access Journals (Sweden)

    René Wilhelm

    2013-11-01

    Full Text Available Chitosan, which is derived from the biopolymer chitin, can be readily dissolved in different ionic liquids. The resulting homogeneous solutions were applied in an asymmetric Aldol reaction. Depending on the type of ionic liquid used, high asymmetric inductions were found. The influence of different additives was also studied. The best results were obtained in [BMIM][Br] without an additive.

  18. Adsorption of hexavalent chromium by graphite–chitosan binary

    Indian Academy of Sciences (India)

    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 ...

  19. Development of docetaxel and alendronate-loaded chitosan ...

    African Journals Online (AJOL)

    Development of docetaxel and alendronate-loaded chitosan-conjugated polylactide-co-glycolide nanoparticles: In vitro characterization in osteosarcoma cells. ... typical time-dependent cellular uptake and also displayed superior cytotoxicity in MG-63 cells compared with blank NPs, which were safe and biocompatible.

  20. Synthesis, characterisation and biomedical applications of curcumin conjugated chitosan microspheres.

    Science.gov (United States)

    Saranya, T S; Rajan, V K; Biswas, Raja; Jayakumar, R; Sathianarayanan, S

    2018-04-15

    Curcumin is a diaryl heptanoid of curcuminoids class obtained from Curcuma longa. It possesses various biological activities like anti-inflammatory, hypoglycemic, antioxidant, wound-healing, and antimicrobial activities. Chitosan is a biocompatible, biodegradable and non-toxic natural polymer which enhances the adhesive property of the skin. Chemical conjugation will leads to sustained release action and to enhance the bioavailability. This study aims to synthesis and characterize biocompatible curcumin conjugated chitosan microspheres for bio-medical applications. The Schiff base reaction was carried out for the preparation of curcumin conjugated chitosan by microwave method and it was characterised using FTIR and NMR. Curcumin conjugated chitosan microspheres (CCCMs) were prepared by wet milling solvent evaporation method. SEM analysis showed these CCCMs were 2-5μm spherical particles. The antibacterial activities of the prepared CCCMs were studied against Staphylococcus aureus and Escherichia coli, the zone of inhibition was 28mm and 23mm respectively. Antioxidant activity of the prepared CCCMs was also studied by DPPH and H 2 O 2 method it showed IC 50 esteem value of 216μg/ml and 228μg/ml, and anti-inflammatory activity results showed that CCCMs having IC 50 value of 45μg/ml. The results conclude that the CCCMs having a good antibacterial, antioxidant and anti-inflammatory activities. This, the prepared CCCMs have potential application in preventing skin infections. Copyright © 2017. Published by Elsevier B.V.