Sample records for targeted gadolinium-loaded chitosan

  1. Gadolinium-loaded chitosan nanoparticles for neutron-capture therapy: Influence of micrometric properties of the nanoparticles on tumor-killing effect.

    PubMed

    Ichikawa, Hideki; Uneme, Takeshi; Andoh, Tooru; Arita, Yuya; Fujimoto, Takuya; Suzuki, Minoru; Sakurai, Yoshinori; Shinto, Hiroyuki; Fukasawa, Tomonori; Fujii, Fumihiko; Fukumori, Yoshinobu

    2014-06-01

    As a nanoparticulate device for controlled delivery of Gd in NCT, the authors have developed gadolinium-loaded chitosan nanoparticles (Gd-nanoCPs). In the present study, influence of micrometric properties such as particle size, particle-surface charge and Gd content of Gd-nanoCPs on tumor-killing effect by Gd-NCT was investigated with Gd-nanoCPs. Two types of Gd-nanoCPs with different mean particle size, zeta potential and Gd-content (Gd-nanoCP-400; 391nm, 28mV, 9wt% and Gd-nanoCP-200; 214nm, 19mV, 24wt%) could be prepared by using chitosans with different molecular weights. Gd-nanoCPs incorporating 1.2mg of natural Gd were injected intratumorally once or twice to mice subcutaneously-bearing B16F10 melanoma. Eight hours after the last administration, thermal neutron was irradiated to tumor region of the mice. Remarkable tumor-growth was observed in both hot and cold control groups. In contrast, Gd-NCT groups showed significant tumor-growth suppression effect, though their efficacy was found to depend on the micrometric properties of Gd-nanoCPs. In particular, the Gd-nanoCP-200 exhibited stronger tumor-killing effect than the Gd-nanoCP-400 at the same Gd dose and it was still similar to Gd-nanoCP-400 in tumor-growth suppressing effect even at the half of Gd dose of Gd-nanoCP-400. This significance in tumor-killing effect would be ascribed from a higher Gd retention in the tumor tissue and an improved distribution of Gd with intratumorally administered Gd-nanoCP-200. Indeed, the Gd concentration in tumor tissue at the time corresponding to the onset of thermal neutron irradiation was determined to be significantly higher in Gd-nanoCP-200, compared with Gd-nanoCP-400. These results demonstrated that appropriate modification of Gd-nanoCPs in micrometric properties would be an effective way to improve the retention of Gd in the tumor tissue after intratumoral injection, leading to the enhanced tumor-killing effect in Gd-NCT. PMID:24462286

  2. Chitosan

    PubMed Central

    Smith, Alan; Perelman, Michael; Hinchcliffe, Michael

    2014-01-01

    The nasal route is attractive for the delivery of vaccines in that it not only offers an easy to use, non-invasive, needle-free alternative to more conventional parenteral injection, but it also creates an opportunity to elicit both systemic and (crucially) mucosal immune responses which may increase the capability of controlling pathogens at the site of entry. Immune responses to “naked” antigens are often modest and it is widely accepted that incorporation of an adjuvant is a prerequisite for the achievement of clinically effective nasal vaccines. Many existing adjuvants are sub-optimal or unsuitable because of local toxicity or poor enhancement of immunogenicity. Chitosan, particularly chitosan salts, have now been used in several preclinical and clinical studies with good tolerability, excellent immune stimulation and positive clinical results across a number of infections. Particularly significant evidence supporting chitosan as an adjuvant for nasal vaccination comes from clinical investigations on a norovirus vaccine; this demonstrated the ability of chitosan (ChiSys®), when combined with monophosphoryl lipid, to evoke robust immunological responses and confer protective immunity following (enteral) norovirus challenge. This article summarizes the totality of the meaningful information (including key unpublished data) supporting the development of chitosan-adjuvanted vaccines. PMID:24346613

  3. Application of chitosan-based nanocarriers in tumor-targeted drug delivery.

    PubMed

    Ghaz-Jahanian, Mohammad Ali; Abbaspour-Aghdam, Farzin; Anarjan, Navideh; Berenjian, Aydin; Jafarizadeh-Malmiri, Hoda

    2015-03-01

    Cancer is one of the major malignant diseases in the world. Current anti tumor agents are restricted during the chemotherapy due to their poor solubility in aqueous media, multidrug resistance problems, cytotoxicity, and serious side effects to healthy tissues. Development of targeted drug nanocarriers would enhance the undesirable effects of anticancer drugs and also selectively deliver them to cancerous tissues. Variety of nanocarriers such as micelles, polymeric nanoparticles, liposomes nanogels, dendrimers, and carbon nanotubes have been used for targeted delivery of anticancer agents. These nanocarriers transfer loaded drugs to desired sites through passive or active efficacy mechanisms. Chitosan and its derivatives, due to their unique properties such as hydrophilicity, biocompatibility, and biodegradability, have attracted attention to be used in nanocarriers. Grafting cancer-specific ligands onto the Chitosan nanoparticles, which leads to ligand-receptor interactions, has been successfully developed as active targeting. Chitosan-conjugated components also respond to external or internal physical and chemical stimulus in targeted tumors that is called environment triggers. In this study, mechanisms of targeted tumor deliveries via nanocarriers were explained; specifically, chitosan-based nanocarriers in tumor-targeting drug delivery were also discussed. PMID:25385004

  4. Folate-targeted liposome encapsulating chitosan/oligonucleotide polyplexes for tumor targeting.

    PubMed

    Kang, Ji Hee; Battogtokh, Gantumur; Ko, Young Tag

    2014-10-01

    We previously reported that a liposome encapsulating polyethylenimine/oligonucleotides is suitable for in vivo delivery of nucleic acid therapeutics. However, toxicity of polyethylenimine is an obstacle in clinical application. To develop a liposome encapsulating polyplexes applicable to clinical use, we proposed to replace polyethylenimine with chitosan and thus constructed the liposome encapsulating low-molecular weight chitosan (LMWC)/oligonucleotide (ODN) polyplexes [LS(CO)]. ODN was completely complexed to LMWC at pH 5.5 and an N/P ratio 10 with a positive zeta potential of 19.81?±?1.11. The positively charged polyplexes were encapsulated into anionic liposome by membrane extrusion. Folate-targeted liposome encapsulating LMWC/ODN complex [FLS(CO)] was prepared by adding folate-conjugated phospholipid. The resulting LS(CO) and FLS(CO) were characterized with respect to size distribution, zeta potential, and colloidal stability. The LS(CO) and FLS(CO) were also evaluated for in vitro cellular uptake and cytotoxicity. The LS(CO) and FLS(CO) showed a narrow size distribution with a mean diameter of about 130 nm and neutral zeta potentials and remained stable for 7 days in 0.15-M NaCl at room temperature. FLS(CO) showed higher cellular uptake than LS(CO) in B16F10 murine melanoma cells. Furthermore, LS(CO) showed less toxicity as compared to liposome encapsulating polyethylenimine/oligonucleotides, representing a biocompatible nanocarrier of oligonucleotide therapeutics. PMID:24848761

  5. Preparation and In vitro Investigation of Chitosan Compressed Tablets for Colon Targeting

    PubMed Central

    Bashardoust, Negar; Jenita, Josephine Leno; Zakeri-Milani, Parvin

    2011-01-01

    Purpose: The aim of the present study was minimizing the drug release in upper gastro intestinal tract and targeting to colon by using the principles of compression coat. Methods: Compression coated tablets of Ibuprofen were prepared by direct compression method using chitosan (300, 250, 200 & 175 mg). Tablets were evaluated for their physicochemical properties and in vitro drug release studies. In vitro drug release studies were performed with and without rat caecal contents. Results: In the rat caecal contents tablets showed enhanced drug release due to degradation of chitosan coat by colonic colonic enzymes. The in vitro release studies in pH-6.8 phosphate buffer containing 2% w/v of rat caecal contents showed the cumulative percentage release of Ibuprofen after 26h as 31.94% ±0.59, 67.89% ± 0.45 and 55.87 % ± 0.45 and 82.52 % ± 0.92 respectively. Coat thickness and amount of chitosan controls the release rate. Formulations are best fitted with Korsmeyer-Peppas kinetics and mechanism of drug release was non-Fickian. FTIR studies reveals there is no drug-polysaccharide interaction. F1 formulation was a promising system for drug targeting to colon. Conclusion: Based on the obtained results chitosan as a press coat could target ibuprofen to the colon. PMID:24312762

  6. Synthesis of Doxorubicin loaded magnetic chitosan nanoparticles for pH responsive targeted drug delivery.

    PubMed

    Unsoy, Gozde; Khodadust, Rouhollah; Yalcin, Serap; Mutlu, Pelin; Gunduz, Ufuk

    2014-10-01

    Targeted drug delivery is a promising alternative to overcome the limitations of classical chemotherapy. In an ideal targeted drug delivery system carrier nanoparticles would be directed to the tumor tissue and selectively release therapeutic molecules. As a novel approach, chitosan coated magnetic nanoparticles (CS MNPs) maintain a pH dependent drug delivery which provides targeting of drugs to the tumor site under a magnetic field. Among various materials, chitosan has a great importance as a pH sensitive, natural, biodegradable, biocompatible and bioadhesive polymer. The aim of this study was to obtain an effective targeted delivery system for Doxorubicin, using chitosan coated MNPs. Different sized CS MNPs were produced by in situ synthesis method. The anti-cancer agent Doxorubicin was loaded onto CS MNPs which were characterized previously. Doxorubicin loading was confirmed by FTIR. Drug loading and release characteristics, and stability of the nanoparticles were investigated. Our results showed that the CS MNPs have pH responsive release characteristics. The cellular internalization of Doxorubicin loaded CS MNPs were visualized by fluorescent microscopy. Doxorubicin loaded CS MNPs are efficiently taken up by MCF-7 (MCF-7/S) and Doxorubicin resistant MCF-7 (MCF-7/1 ?M) breast cancer cells, which increases the efficacy of drug and also maintains overcoming the resistance of Doxorubicin in MCF-7/Dox cells. Consequently, CS MNPs synthesized at various sizes can be effectively used for the pH dependent release of Doxorubicin in cancer cells. Results of this study can provide new insights in the development of pH responsive targeted drug delivery systems to overcome the side effects of conventional chemotherapy. PMID:24931189

  7. Mannosylated Chitosan Nanoparticles for Delivery of Antisense Oligonucleotides for Macrophage Targeting

    PubMed Central

    Asthana, Abhay; Kohli, Dharm Veer; Vyas, Suresh Prasad

    2014-01-01

    The therapeutic potential of antisense oligonucleotides (ASODN) is primarily dependent upon its safe and efficient delivery to specific cells overcoming degradation and maximizing cellular uptake in vivo. The present study focuses on designing mannosylated low molecular weight (LMW) chitosan nanoconstructs for safe ODNs delivery by macrophage targeting. Mannose groups were coupled with LMW chitosan and characterized spectroscopically. Mannosylated chitosan ODN nanoparticles (MCHODN NPs) were formulated by self-assembled method using various N/P ratio (moles of amine groups of MCH to phosphate moieties of ODNs) and characterized for gel retardation assay, physicochemical characteristics, cytotoxicity and transfection efficiency, and antisense assay. Complete complexation of MCH/ODN was achieved at charge ratio of 1:1 and above. On increasing the N/P ratio of MCH/ODN, particle size of the NPs decreased whereas zeta potential (ZV) increased. MCHODN NPs displayed much higher transfection efficiency into Raw 264.7 cells (bears mannose receptors) than Hela cells and no significant toxicity was observed at all MCH concentrations. Antisense assay revealed that reduction in lipopolysaccharide (LPS) induced serum TNF-? is due to antisense activity of TJU-2755 ODN (sequence complementary to 3?-UTR of TNF-?). These results suggest that MCHODN NPs are acceptable choice to improve transfection efficiency in vitro and in vivo. PMID:25057492

  8. Development of (153) Sm-folate-polyethyleneimine-conjugated chitosan nanoparticles for targeted therapy.

    PubMed

    Mollarazi, Esmail; Jalilian, Amir R; Johari-Daha, Fariba; Atyabi, Fatemeh

    2015-06-30

    The aim of this study was to develop biocompatible, water-soluble (153) Sm-labeled chitosan nanoparticles (NPs) containing folate and polyethyleneimine functionalities i.e. chitosan-graft-PEI-folate (CHI-DTPA-g-PEI-FA), suitable for targeted therapy. The physicochemical properties of the obtained NPs were characterized by dynamic light-scattering analysis for their mean size, size distribution, and zeta potential; scanning electron microscopy for surface morphology; and (1) H-NMR, FT-IR analyses for molecular dispersity of folate in the NPs. NPs were spherical with mean diameter below 250?nm, polydispersity of below 0.15, and positive zeta potential values. The NP complex ((153) Sm-CHI-DTPA-g-PEI-FA) was stable at 25?°C (6-8?h, >90% radiochemical purity, instant thin layer chromatography (ITLC)). Binding studies using fluorescent NPs for internalization also demonstrated significant uptake in MCF-7 cells. MCF-7 cell internalization was significantly greater for 4T1. In blocking studies, both MCF-7 and 4T1 cell lines demonstrated specific folate receptor (FR) binding (decreasing 45%). In vivo biodistribution studies indicated major excretion of NPs metabolites and/or free (153) Sm through the kidneys. The preliminary imaging studies in 4T1 tumor-bearing mice showed minor uptake up to 96?h. The present folic acid that functionalized chitosan NP is a candidate material for folate receptor therapy. PMID:26036233

  9. Formulation and evaluation of chitosan microspheres of aceclofenac for colon-targeted drug delivery.

    PubMed

    Umadevi, S K; Thiruganesh, R; Suresh, S; Reddy, K Bhaskar

    2010-10-01

    The objective of this investigation was to develop novel colon specific drug delivery. Aceclofenac, a NSAID, was successfully encapsulated into chitosan microspheres. Various formulations were prepared by varying the ratio of chitosan, span-85 and stirring speed and the amount of glutaraldehyde. The SEM study showed that microspheres have smooth surfaces. Microspheres were characterised by Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) to confirm the absence of chemical interactions between drug and polymer and to know the formation of microspheres structure. The microspheres were evaluated for particle size, encapsulation efficiency, drug loading capacity, mucoadhesion studies, stability studies, in vitro and in vivo drug release studies. Particle sizes, as measured by the laser light scattering technique, were of an average size in the range 41-80?µm. The swelling index was in the range 0.37-0.82 and the entrapment efficiency range was 51-75% for all the formulations. The optimised batch ACM(13) released 83.6% at 8?h and 104% at 24?h in SCF containing rat caecal content. Eudragit coated chitosan microspheres prevented the release of the aceclofenac in the physiological environment of the stomach and small intestine and released 95.9±0.34% in the colon. With regard to release kinetics, the data were best fitted with the Higuchi model and showed zero order release with non-Fickian diffusion mechanism. The in vivo findings suggest that aceclofenac microspheres exhibit a prolonged effect of aceclofenac in rats and produce a significant anti-inflammatory effect. The findings of the present study conclusively state that chitosan microspheres are promising for colon targeting of aceclofenac to synchronise with chronobiological symptoms of rheumatoid arthritis. PMID:20848388

  10. Folate conjugated chitosan grafted thiazole orange derivative with high targeting for early breast cancer cells diagnosis.

    PubMed

    Fei, Xue-Ning; Liu, Yin; Li, Chao

    2012-11-01

    The folate receptor (FR) is over-expressed on many solid tumors and has been exploited for targeted delivery of folic acid linked liposomes to cancer cells in vitro. In the present study, we developed a novel folic acid (FA) conjugated chitosan (CTS) grafted thiazole orange (TO) complex (FA-CTS-TO), and the formation can be used to label tumor cells. The structure of TO derivatives was confirmed by (1)H NMR and MS, and the fluorescence probe of FA-CTS-TO complex was confirmed by Fourier transform infrared analysis and Differential thermal analysis. The in vitro and in vivo of FA-CTS-TO complex were tested in breast cancer cells and the results showed a high targeting specificity in tumor cells with FR over-expressed. Such prominent fluorescence properties demonstrate again that FA-CTS-TO complex as a tumor targeting fluorescence probe is appropriate for breast cancer cells. PMID:22752402

  11. The implications of recent advances in carboxymethyl chitosan based targeted drug delivery and tissue engineering applications.

    PubMed

    Upadhyaya, Laxmi; Singh, Jay; Agarwal, Vishnu; Tewari, Ravi Prakash

    2014-07-28

    Over the last decade carboxymethyl chitosan (CMCS) has emerged as a promising biopolymer for the development of new drug delivery systems and improved scaffolds along with other tissue engineering devices for regenerative medicine that is currently one of the most rapidly growing fields in the life sciences. CMCS is amphiprotic ether, derived from chitosan, exhibiting enhanced aqueous solubility, excellent biocompatibility, controllable biodegradability, osteogenesis ability and numerous other outstanding physicochemical and biological properties. More strikingly, it can load hydrophobic drugs and displays strong bioactivity which highlight its suitability and extensive usage for preparing different drug delivery and tissue engineering formulations respectively. This review provides a comprehensive introduction to various types of CMCS based formulations for delivery of therapeutic agents and tissue regeneration and further describes their preparation procedures and applications in different tissues/organs. Detailed information of CMCS based nano/micro systems for targeted delivery of drugs with emphasis on cancer specific and organ specific drug delivery have been described. Further, we have discussed various CMCS based tissue engineering biomaterials along with their preparation procedures and applications in different tissues/organs. The article then, gives a brief account of therapy combining drug delivery and tissue engineering. Finally, identification of major challenges and opportunities for current and ongoing application of CMCS based systems in the field are summarised. PMID:24806482

  12. Comparison of PLGA and lecithin/chitosan nanoparticles for dermal targeting of betamethasone valerate.

    PubMed

    Özcan, Ipek; Azizo?lu, Erkan; Senyi?it, Taner; Özyazici, Mine; Özer, Özgen

    2013-07-01

    Poly(lactide-co-glycolide) (PLGA) and lecithin/chitosan (LC) nanoparticles were prepared to evaluate the difference in the behavior upon administration on skin, for steroidal treatment. For this purpose, betamethasone-17-valerate (BMV)-loaded nanoparticles with a narrow size distribution and high entrapment efficiency were prepared. Permeation studies showed that both polymeric nanoparticles enhanced the amount of BMV in epidermis, which is the target site of topical steroidal treatment, when compared with commercial formulation. 1.58-Fold increase was determined in the epidermis concentration of BMV by LC nanoparticles with respect to PLGA nanoparticles. Nanoparticles were diluted in chitosan gel (10%, w/w) to prepare suitable formulation for topical application. Accumulation from both gel formulations were found significantly higher than commercial formulation in skin layers (p < 0.05). In addition, pharmacodynamic responses were also investigated as anti-inflammatory and skin-blanching parameters. Both formulations significantly improved these parameters although they contained 10 times less amount of BMV than commercial cream. Moreover, TEWL measurement exhibited no barrier function changes upon the application of nanoparticles on skin. Overall, both nanoparticles improved the localization of BMV within skin layers; but when compared with PLGA nanoparticles, the LC nanoparticles could be classified as a better candidate for topical delivery vehicle in the treatment of various dermatological inflammatory diseases. PMID:23390922

  13. Antimicrobial and anti-inflammatory activity of chitosan-alginate nanoparticles: a targeted therapy for cutaneous pathogens

    PubMed Central

    Friedman, Adam J; Phan, Jenny; Schairer, David; Champer, Jackson; Qin, Min; Pirouz, Aslan; Blecher, Karin; Oren, Ami; Liu, Phil; Modlin, Robert L; Kim, Jenny

    2012-01-01

    Advances in nanotechnology have demonstrated potential application of nanoparticles for effective and targeted drug delivery. Here, we investigated the antimicrobial and immunological properties and the feasibility of using nanoparticles to deliver antimicrobial agents to treat a cutaneous pathogen. Nanoparticles synthesized with chitosan and alginate demonstrated a direct antimicrobial activity in vitro against Propionibacterium acnes, the bacterium linked to the pathogenesis of acne. By electron microscopy imaging, chitosan-alginate nanoparticles were found to induce disruption of the P. acnes cell membrane, providing a mechanism for the bactericidal effect. The chitosan-alginate nanoparticles also exhibited anti-inflammatory properties as they inhibited P. acnes induced inflammatory cytokine production in human monocytes and keratinocytes. Furthermore, benzoyl peroxide, a commonly used anti-acne drug, was effectively encapsulated in the chitosan-alginate nanoparticles and demonstrated superior antimicrobial activity against P. acnes compared to benzoyl peroxide alone while demonstrating less toxicity to eukaryotic cells. Together, these data suggest the potential utility of topical delivery of chitosan-alginate nanoparticle encapsulated drug therapy for the treatment of dermatologic conditions with infectious and inflammatory components. PMID:23190896

  14. Biodegradable Chitosan Magnetic Nanoparticle Carriers for Sub-Cellular Targeting Delivery of Artesunate for Efficient Treatment of Breast Cancer

    NASA Astrophysics Data System (ADS)

    Subramanian, Natesan; Abimanyu, Sugumaran; Vinoth, Jeevanesan; Sekar, Ponnusamy Chandra

    2010-12-01

    Artesunate is a semi-synthetic derivative of artemisinin, the active principle extracted from Artemisia annua. It possesses good anti-proliferative activity and anti-angiogenic activity with very low toxicity to normal healthy cells. The drawback of most cancer drugs is their inability to accumulate selectively in the cancerous cells. So, large quantities of doses have to be administered to get the required therapeutic concentration in the target site and it resulted in many serious side effects due to the exposure of healthy cells to higher concentrations of cytotoxic drugs. The problem may be solved by selectively and quantitatively accumulating the drug at target site using magnetic nanoparticles guided by an externally applied magnetic field. A modest attempt has been made in this present study, the artesunate magnetic nanoparticle was successfully formulated using two forms of chitosan and evaluated for its in-vitro characteristics like surface morphology, particle size and distribution, zeta potential, magnetic susceptibility, encapsulation efficiency, loading capacity and in-vitro drug release. The synthesized magnetite size was 73 nm and the size of developed magnetic nanoparticles of artesunate was in the range of 90 to 575 nm. Acetic acid soluble chitosan at low concentration exhibit highest encapsulation efficiency and drug loading whereas increase in water soluble chitosan concentration increases the encapsulation efficiency and drug loading in formulations. The developed chitosan magnetic nanoparticles of artesunate shows better release characteristics and may be screened for its in-vivo breast cancer activity.

  15. Pectin-coated chitosan-LDH bionanocomposite beads as potential systems for colon-targeted drug delivery.

    PubMed

    Ribeiro, Lígia N M; Alcântara, Ana C S; Darder, Margarita; Aranda, Pilar; Araújo-Moreira, Fernando M; Ruiz-Hitzky, Eduardo

    2014-03-10

    This work introduces results on a new drug delivery system (DDS) based on the use of chitosan/layered double hydroxide (LDH) biohybrid beads coated with pectin for controlled release in the treatment of colon diseases. Thus, the 5-aminosalicylic acid (5ASA), the most used non-steroid-anti-inflammatory drug (NSAID) in the treatment of ulcerative colitis and Crohn's disease, was chosen as model drug aiming to a controlled and selective delivery in the colon. The pure 5ASA drug and the hybrid material prepared by intercalation in a layered double hydroxide of Mg2Al using the co-precipitation method, were incorporated in a chitosan matrix in order to profit from its mucoadhesiveness. These compounds processed as beads were further treated with the polysaccharide pectin to create a protective coating that ensures the stability of both chitosan and layered double hydroxide at the acid pH of the gastric fluid. The resulting composite beads presenting the pectin coating are stable to water swelling and procure a controlled release of the drug along their passage through the simulated gastrointestinal tract in in vitro experiments, due to their resistance to pH changes. Based on these results, the pectin@chitosan/LDH-5ASA bionanocomposite beads could be proposed as promising candidates for the colon-targeted delivery of 5ASA, with the aim of acting only in the focus of the disease and minimizing side effects. PMID:24374607

  16. Chitosan and its quaternized derivative as effective long dsRNA carriers targeting shrimp virus in Spodoptera frugiperda 9 cells.

    PubMed

    Theerawanitchpan, Gatesara; Saengkrit, Nattika; Sajomsang, Warayuth; Gonil, Pattarapond; Ruktanonchai, Uracha; Saesoo, Somsak; Flegel, Timothy W; Saksmerprome, Vanvimon

    2012-08-31

    RNA interference (RNAi) is a promising strategy to combat shrimp viral pathogens at lab-scale experiments. Development of effective orally delivered agents for double-stranded (ds)RNA is necessary for RNAi application at farm level. Since continuous shrimp cell lines have not been established, we are developing a dsRNA-delivery system in Spodoptera frugiperda (Sf9) cells for studying in vitro RNAi-mediated gene silencing of shrimp virus. Sf9 cells challenged with yellow head virus (YHV) were used for validating nanoparticles as effective dsRNA carriers. Inexpensive and biodegradable polymers, chitosan and its quarternized derivative (QCH4), were formulated with long dsRNA (>100 bp) targeting YHV. Their morphology and physicochemical properties were examined. When treated with chitosan- and QCH4-dsRNA complexes, at least 50% reduction in YHV infection in Sf9 cells relative to the untreated control was evident at 24h post infection with low cytoxicity. Inhibitory effects of chitosan- and QCH4-dsRNA complexes were comparable to that of dsRNA formulated with Cellfectin(®), a commercial lipid-based transfection reagent. The natural and quaternized chitosan prepared in this study can be used for shrimp virus-specific dsRNA delivery in insect cultures, and have potential for future development of dsRNA carriers in shrimp feed. PMID:22575788

  17. Folate receptor targeted, carboxymethyl chitosan functionalized iron oxide nanoparticles: a novel ultradispersed nanoconjugates for bimodal imaging

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Dipsikha; Das, Manasmita; Mishra, Debashis; Banerjee, Indranil; Sahu, Sumanta K.; Maiti, Tapas K.; Pramanik, Panchanan

    2011-04-01

    This article delineates the design and synthesis of a novel, bio-functionalized, magneto-fluorescent multifunctional nanoparticles suitable for cancer-specific targeting, detection and imaging. Biocompatible, hydrophilic, magneto-fluorescent nanoparticles with surface-pendant amine, carboxyl and aldehyde groups were designed using o-carboxymethyl chitosan (OCMC). The free amine groups of OCMC stabilized magnetite nanoparticles on the surface allow for the covalent attachment of a fluorescent dye such as rhodamine isothiocyanate (RITC) with the aim to develop a magneto-fluorescent nanoprobe for optical imaging. In order to impart specific cancer cell targeting properties, folic acid and its aminated derivative was conjugated onto these magneto-fluorescent nanoparticles using different pendant groups (-NH2, -COOH, -CHO). These newly synthesized iron-oxide folate nanoconjugates (FA-RITC-OCMC-SPIONs) showed excellent dispersibility, biocompatibility and good hydrodynamic sizes under physiological conditions which were extensively studied by a variety of complementary techniques. The cellular internalization efficacy of these folate-targeted and its non-targeted counterparts were studied using a folate-overexpressed (HeLa) and a normal (L929 fibroblast) cells by fluorescence microscopy and magnetically activated cell sorting (MACS). Cell-uptake behaviors of nanoparticles clearly demonstrate that cancer cells over-expressing the human folate receptor internalized a higher level of these nanoparticle-folate conjugates than normal cells. These folate targeted nanoparticles possess specific magnetic properties in the presence of an external magnetic field and the potential of these nanoconjugates as T2-weighted negative contrast MR imaging agent were evaluated in folate-overexpressed HeLa and normal L929 fibroblast cells.

  18. Both FA- and mPEG-conjugated chitosan nanoparticles for targeted cellular uptake and enhanced tumor tissue distribution

    PubMed Central

    2011-01-01

    Both folic acid (FA)- and methoxypoly(ethylene glycol) (mPEG)-conjugated chitosan nanoparticles (NPs) had been designed for targeted and prolong anticancer drug delivery system. The chitosan NPs were prepared with combination of ionic gelation and chemical cross-linking method, followed by conjugation with both FA and mPEG, respectively. FA-mPEG-NPs were compared with either NPs or mPEG-/FA-NPs in terms of their size, targeting cellular efficiency and tumor tissue distribution. The specificity of the mPEG-FA-NPs targeting cancerous cells was demonstrated by comparative intracellular uptake of NPs and mPEG-/FA-NPs by human adenocarcinoma HeLa cells. Mitomycin C (MMC), as a model drug, was loaded to the mPEG-FA-NPs. Results show that the chitosan NPs presented a narrow-size distribution with an average diameter about 200 nm regardless of the type of functional group. In addition, MMC was easily loaded to the mPEG-FA-NPs with drug-loading content of 9.1%, and the drug releases were biphasic with an initial burst release, followed by a subsequent slower release. Laser confocal scanning imaging proved that both mPEG-FA-NPs and FA-NPs could greatly enhance uptake by HeLa cells. In vivo animal experiments, using a nude mice xenograft model, demonstrated that an increased amount of mPEG-FA-NPs or FA-NPs were accumulated in the tumor tissue relative to the mPEG-NPs or NPs alone. These results suggest that both FA- and mPEG-conjugated chitosan NPs are potentially prolonged drug delivery system for tumor cell-selective targeting treatments. PMID:22027239

  19. Folate conjugated carboxymethyl chitosan–manganese doped zinc sulphide nanoparticles for targeted drug delivery and imaging of cancer cells

    Microsoft Academic Search

    Manjusha Elizabeth Mathew; Jithin C. Mohan; K. Manzoor; S. V. Nair; H. Tamura; R. Jayakumar

    2010-01-01

    We developed a novel folic acid (FA) conjugated carboxymethyl chitosan coordinated to manganese doped zinc sulphide quantum dot (FA–CMC–ZnS:Mn) nanoparticles. The system can be used for targeting, controlled drug delivery and also imaging of cancer cells. The prepared nanoparticles were characterized using SEM, AFM, FT-IR, UV and DLS studies. The size range of 5-FU encapsulated FA–CMC–ZnS:Mn nanoparticles were from 130

  20. Development and Evaluation of Chitosan-Coated Liposomes for Oral DNA Vaccine: The Improvement of Peyer’s Patch Targeting Using a Polyplex-Loaded Liposomes

    Microsoft Academic Search

    Sunee Channarong; Wanpen Chaicumpa; Nuttanan Sinchaipanid; Ampol Mitrevej

    2011-01-01

    The aim of this study was to develop chitosan-coated and polyplex-loaded liposomes (PLLs) containing DNA vaccine for Peyer’s\\u000a patch targeting. Plain liposomes carrying plasmid pRc\\/CMV-HBs were prepared by the reverse-phase evaporation method. Chitosan\\u000a coating was carried out by incubation of the liposomal suspensions with chitosan solution. Main lipid components of liposomes\\u000a were phosphatidylcholine\\/cholesterol. Sodium deoxycholate and dicetyl phosphate were used

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

    PubMed

    Chen, Feng-Ying; Yan, Jing-Jing; Yi, Han-Xi; Hu, Fu-Qiang; Du, Yong-Zhong; Yuan, Hong; You, Jian; Zhao, Meng-Dan

    2014-01-01

    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 ?g/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 tumor. PMID:25298734

  2. Bufalin loaded biotinylated chitosan nanoparticles: an efficient drug delivery system for targeted chemotherapy against breast carcinoma.

    PubMed

    Tian, Xin; Yin, Hongzhuan; Zhang, Shichen; Luo, Ying; Xu, Kai; Ma, Ping; Sui, Chengguang; Meng, Fandong; Liu, Yunpeng; Jiang, Youhong; Fang, Jun

    2014-08-01

    Bufalin is a traditional oriental medicine which is known to induce apoptosis in many tumor cells, and it is thus considered as a new anticancer therapeutic. By now, most of the studies of bufalin are in vitro, however in vivo evaluations of its therapeutic efficacy are less and are in great demand for its development toward anticancer drug. One of the problems probably hampering the development of bufalin is the lack of tumor selectivity, which may reduce the therapeutic effect as well as showing side effects. To overcome this drawback, in this study, we designed a tumor-targeted drug delivery system of bufalin based on enhanced permeability and retention (EPR) effect, by using biotinylated chitosan, resulting in bufalin encapsulating nanoparticles (Bu-BCS-NPs) with mean hydrodynamic size of 171.6 nm, as evidenced by dynamic light scattering and transmission electron microscope. Bu-BCS-NPs showed a relative slow and almost linear release of bufalin, and about 36.8% of bufalin was released in 24 h when dissolved in sodium phosphate buffer. Compared to native bufalin, Bu-BCS-NPs exhibited a stronger cytotoxicity against breast cancer MCF-7 cells (IC50 of 0.582 ?g/ml vs 1.896 ?g/ml of native bufalin). Similar results were also obtained in intracellular reactive oxygen species production, apoptosis induction, and decrease in mitochondria membrane potential. These results may contribute to the rapid intracellular uptake of nanoparticles, partly benefiting from the highly expressed biotin receptors in tumor cells. In vivo studies using MCF-7 tumor models in nude mice confirmed the remarkable therapeutic effect of Bu-BCS-NPs. These findings suggest the potential of Bu-BCS-NPs as an anticancer drug with tumor targeting property. PMID:24846793

  3. Efficient Nonviral Gene Therapy Using Folate-Targeted Chitosan-DNA Nanoparticles In Vitro

    PubMed Central

    Jreyssaty, Christian; Shi, Qin; Wang, Huijie; Qiu, Xingping; Winnik, Françoise M.; Zhang, Xiaoling; Dai, Kerong; Benderdour, Mohamed; Fernandes, Julio C.

    2012-01-01

    Nonviral cationic polymers like chitosan can be combined with DNA to protect it from degradation. The chitosan is a biocompatible, biodegradable, nontoxic, and cheap polycationic polymer with low immunogenicity. The objective of this study was to synthesize and then assess different chitosan-DNA nanoparticles and to select the best ones for selective in vitro transfection in human epidermoid carcinoma (KB) cell lines. It revealed that different combinations of molecular weight, the presence or absence of folic acid ligand, and different plasmid DNA sizes can lead to nanoparticles with various diameters and diverse transfection efficiencies. The intracellular trafficking, nuclear uptake, and localization are also studied by confocal microscopy, which confirmed that DNA was delivered to cell nuclei to be expressed. PMID:22474605

  4. Preparation of estradiol chitosan nanoparticles for improving nasal absorption and brain targeting

    Microsoft Academic Search

    Xiaomei Wang; Na Chi; Xing Tang

    2008-01-01

    The estradiol(E2)-loaded chitosan nanoparticles (CS-NPs) were prepared by ionic gelation of chitosan with tripolyphosphate anions (TPP). The CS-NPs had a mean size of (269.3±31.6)nm, a zeta potential of +25.4mV, and loading capacity of E2 CS-NPs suspension was 1.9mgml?1, entrapment efficiency was 64.7% on average. Subsequently, this paper investigated the levels of E2 in blood and the cerebrospinal fluid (CSF) in

  5. Development of chitosan oligosaccharide-modified gold nanorods for in vivo targeted delivery and noninvasive imaging by NIR irradiation.

    PubMed

    Charan, Shobhit; Sanjiv, Kumar; Singh, Narendra; Chien, Fan-Ching; Chen, Yi-Fan; Nergui, Navchtsetseg Navchaa; Huang, Shih-Hsin; Kuo, Chiung Wen; Lee, Te-Chang; Chen, Peilin

    2012-11-21

    In the present study, we demonstrate the synthesis and applications of multifunctional gold nanorod-based probes for specific targeting and noninvasive imaging based on localized heating generated by gold nanorods after NIR irradiation. The structural design of the probe consists of MUA (11-mercaptoundecanoic acid)-capped gold nanorods covalently linked with low-molecular-weight chitosan oligosaccharide (M(w) ~5000) via carbodiimide (EDC) coupling agent. This surface modification is performed for complete replacement of toxic CTAB (hexadecyltrimethyl-ammonium chloride) and acid-responsive delivery of gold nanorods in acidic environment as known to be present at tumor surrounding areas. The resulting chitosan oligosaccharide-modified gold nanorods (CO-GNRs) were further conjugated with tumor targeting monoclonal antibody against EGFR (epidermal growth factor receptor) to provide localized targeting functionality owing to the overexpression of EGFR in human oral adenosquamous carcinoma cell line CAL 27. Initial in vitro and in vivo toxicity assessments indicated that CO-GNRs did not induce any significant toxicity and are thus suitable for biological applications. Furthermore, selective targeting and accumulation of CO-GNRs were observed in vitro via two-photon luminescence imaging studies in CAL 27, which was also observed through in vivo targeting studies performed via NIR (near-infrared) laser irradiation in CAL 27 xenografts of BALB/c nude mice. Hence, the CO-GNRs that we have developed are biocompatible and nontoxic and can be a potential candidate for in vivo targeted delivery, noninvasive imaging based on localized hyperthermia, and photothermal-related therapies. PMID:23030814

  6. Chitosan–pectin polyelectrolyte complex as a carrier for colon targeted drug delivery

    PubMed Central

    Pandey, Sonia; Mishra, Ashish; Raval, Pooja; Patel, Hetal; Gupta, Arti; Shah, Dinesh

    2013-01-01

    Objective The objective of present work was to prepare a polyelectrolyte complex (PEC) between chitosan (polycation) & pectin (polyanion) and to develop enteric coated tablets for colon delivery using the PEC. Methodology The PECs were prepared using different concentrations of chitosan and pectin. Drug loaded enteric coated tablets were prepared by wet granulation method using PEC to sustain the release at colon and coating was done with Eudragit S 100 to prevent the early release of the drug in stomach and intestine. Two independent variable, % PEC (chitosan/pectin) and % coating were optimized by 32 full factorial design. Statistical model were also used to supplement the optimization. DSC was performed to confirm the interaction between the polyions. Developed formulations were evaluated for physical appearance, weight variation, thickness, hardness, friability, % swelling, assay, in-vitro and ex-vivo drug release studies to investigate the PEC's ability to deliver the drug to colon. Ex-vivo release study using rat caecal content was also carried out on optimized formulation. Results and discussion DSC results confirmed chitosan/pectin interaction and subsequent formation of PEC. The optimized formulation containing 1.1% of PEC and 3% of coating showed highest swelling and release in alkaline pH mechanism of which was found to be microbial enzyme dependent degradation established by ex-vivo study using rat caecal content. PMID:24563596

  7. Properties and evaluation of quaternized chitosan/lipid cation polymeric liposomes for cancer-targeted gene delivery.

    PubMed

    Liang, Xiaofei; Li, Xiaoyu; Chang, Jin; Duan, Yourong; Li, Zonghai

    2013-07-01

    Development of high-stability and efficient nonviral vectors with low cytoxicity is important for targeted tumor gene therapy. In this study, cationic polymeric liposomes (CPLs), with similar lipid bilayer structure and high thermal stability, were prepared from polymeric surfactants of quaternized (carboxymethyl)chitosan with different carbon chains (dodecyl, tetradecyl, hexadecyl, and octadecyl). By comparing different factors that influence gene delivery, tetradecyl-quaternized (carboxymethy)chitosan (TQCMC) CPLs, with suitable size (184.4 ± 17.1 nm), ? potentials (27.5 ± 4.9 mV), and productivity for synthesis TQCMC (weight yield 13.1%), were selected for gene transfection evaluation in various cancer cell lines. Although TQCMC CPLs have lower gene transfection efficiency compared with cationic liposomes (Lipofectamine 2000) in vitro, they displayed higher reporter gene delivery ability for cancer tissues (bearing U87 and SMMC-7721 tumors) in vivo after intravenous injection. TQCMC CPLs also have lower cell cytotoxicity and lower cytokine production or liver injury for BALB/c mice. We conclude that the CPLs are promising gene delivery systems that may be used to target various cancers. PMID:23763489

  8. A novel drug "copper acetylacetonate" loaded in folic acid-tagged chitosan nanoparticle for efficient cancer cell targeting.

    PubMed

    Pramanik, Arindam; Laha, Dipranjan; Pramanik, Panchanan; Karmakar, Parimal

    2014-01-01

    Several copper compounds have proven anti-cancer activity. Similarly, curcumin a derivative of 1,3 diketone, which is not plenty in nature, has comparable anti-cancer activity. In this work, we have explored the synergistic anti-cancer activity of copper ion and acetylacetone complex containing 1,3 diketone group. The cytotoxicity of the copper acetylacetonate (CuAA) complex was evaluated on various cancer cells and LD50 doses were determined. To investigate the mechanism, various biochemical assays were performed and reactive oxygen species as well as the glutathione level in the cell were found to be increased after the treatment with the above-mentioned complex. Further this reagent induced apoptosis and reduced mitochondrial membrane potential of the cells. Because of the poor solubility and reasonable cytotoxicity of CuAA, polymer nanoparticles (NPs) of chitosan derivatives were used for delivery in cancer cells. For the targeted delivery, folic acid-tagged hydrophobic-modified chitosan NPs were developed and the CuAA was encapsulated. Finally, these drug-encapsulated NPs were successfully delivered to folate receptor over-expressed cancer cells. Thus using nanotechnology, we developed an anti-cancer agent suitable for targeted delivery. PMID:23987131

  9. Galactosylated chitosan-g-PEI/DNA complexes-loaded poly(organophosphazene) hydrogel as a hepatocyte targeting gene delivery system.

    PubMed

    Jiang, Hu-Lin; Kim, You-Kyoung; Lee, Sun-Mi; Park, Mi-Ran; Kim, Eun-Mi; Jin, Yong-Mei; Arote, Rohidas; Jeong, Hwan-Jeong; Song, Soo-Chang; Cho, Myung-Haing; Cho, Chong-Su

    2010-04-01

    Hydrogels are widely used in drug delivery systems because they can control the release and thereby enhance the efficiency of locally delivered bioactive molecules such as therapeutic drugs, proteins, or genes. For gene delivery, localized release of plasmid DNA or polymer/DNA complexes can transfect cells and produce sustained protein production. We tested the galactosylated chitosan-graft-polyethylenimine (GC-g-PEI)/DNA complexes-loaded poly(organophosphazene) thermosensitive biodegradable hydrogel as a hepatocyte targeting gene delivery system. The poly(organophosphazene) hydrogel loaded with GC-g-PEI/DNA complexes showed low cytotoxicity and higher transfection efficiency than PEI/DNA complexes, as well as good hepatocyte specificity in vitro and in vivo. Our results indicate that poly(organophosphazene) hydrogels loaded with GC-g-PEI/DNA complexes may be a safe and efficient hepatocyte targeting gene delivery system. PMID:20422364

  10. Docetaxel-Loaded Chitosan Microspheres as a Lung Targeted Drug Delivery System: In Vitro and in Vivo Evaluation

    PubMed Central

    Wang, Hao; Xu, Yongdong; Zhou, Xiao

    2014-01-01

    The aim of this study was to prepare docetaxel-loaded chitosan microspheres and to evaluate their in vitro and in vivo characteristics. Glutaraldehyde crosslinked microspheres were prepared using a water-in-oil emulsification method, and characterized in terms of the morphological examination, particle size distribution, encapsulation ratio, drug-loading coefficient and in vitro release. Pharmacokinetics and biodistribution studies were used to evaluate that microspheres have more advantage than the conventional formulations. The emulsion crosslinking method was simple to prepare microspheres and easy to scale up. The formed microspheres were spherical in shape, with a smooth surface and the size was uniform (9.6 ± 0.8 ?m); the encapsulation efficiency and drug loading of prepared microspheres were 88.1% ± 3.5% and 18.7% ± 1.2%, respectively. In vitro release indicated that the DTX microspheres had a well-sustained release efficacy and in vivo studies showed that the microspheres were found to release the drug to a maximum extent in the target tissue (lung). The prepared microspheres were found to possess suitable physico-chemical properties and the particle size range. The sustained release of DTX from microspheres revealed its applicability as drug delivery system to minimize the exposure of healthy tissues while increasing the accumulation of therapeutic drug in target sites. PMID:24577314

  11. Nanoparticles of deoxycholic acid, polyethylene glycol and folic acid-modified chitosan for targeted delivery of doxorubicin.

    PubMed

    Shi, Zhonggen; Guo, Rui; Li, Weichang; Zhang, Yi; Xue, Wei; Tang, Yu; Zhang, Yuanming

    2014-03-01

    Chitosan (CS) was first modified hydrophobically with deoxycholic acid (DCA) and then with polyethylene glycol (PEG) to obtain a novel amphiphilic polymer (CS-DCA-PEG). This was covalently bound to folic acid (FA) to develop nanoparticles (CS-DCA-PEG-FA) with tumor cell targeting property. The structure of the conjugates was characterised using Fourier transform infrared and (1)H nuclear magnetic resonance spectroscopy and X-ray diffraction. Based on self-aggregation, the conjugates formed nanoparticles with a low critical aggregation concentration of 0.035 mg/ml. The anti-cancer drug doxorubicin (DOX) was encapsulated into the nanoparticles with a drug-loading capacity of 30.2 wt%. The mean diameter of the DOX-loaded nanoparticles was about 200 nm, with a narrow size distribution. Transmission electron microscopy images showed that the DOX-loaded nanoparticles were spherical. The drug release was studied under different conditions. Furthermore, the cytotoxic activities of DOX in CS-DCA-PEG-FA nanoparticles against folate receptor (FR)-positive HeLa cells and FR-negative fibroblast 3T3 cells were evaluated. These results suggested that the CS-DCA-PEG-FA nanoparticles may be a promising vehicle for the targeting anticancer drug to tumor cells. PMID:24327111

  12. Hydrophobically modified glycol chitosan nanoparticles-encapsulated camptothecin enhance the drug stability and tumor targeting in cancer therapy

    Microsoft Academic Search

    Kyung Hyun Min; Yoo-Shin Kim; Sang Mun Bae; Seulki Lee; Hyung Gon Jo; Rang-Woon Park; In-San Kim; Seo Young Jeong; Kwangmeyung Kim; Ick Chan Kwon

    2008-01-01

    To prepare a water-insoluble camptothecin (CPT) delivery carrier, hydrophobically modified glycol chitosan (HGC) nanoparticles were constructed by chemical conjugation of hydrophobic 5?-cholanic acid moieties to the hydrophilic glycol chitosan backbone. Insoluble anticancer drug, CPT, was easily encapsulated into HGC nanoparticles by a dialysis method and the drug loading efficiency was above 80%. CPT-encapsulated HGC (CPT-HGC) nanoparticles formed nano-sized self-aggregates in

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

    PubMed Central

    Alam, Sanjar; Khan, Zeenat I; Mustafa, Gulam; Kumar, Manish; Islam, Fakhrul; Bhatnagar, Aseem; Ahmad, Farhan J

    2012-01-01

    Chitosan (CS) nanoparticles of thymoquinone (TQ) were prepared by the ionic gelation method and are characterized on the basis of surface morphology, in vitro or ex vivo release, dynamic light scattering, and X-ray diffractometry (XRD) studies. Dynamic laser light scattering and transmission electron microscopy confirmed the particle diameter was between 150 to 200 nm. The results showed that the particle size of the formulation was significantly affected by the drug:CS ratio, whereas it was least significantly affected by the tripolyphosphate:CS ratio. The entrapment efficiency and loading capacity of TQ was found to be 63.3% ± 3.5% and 31.23% ± 3.14%, respectively. The drug-entrapment efficiency and drug-loading capacity of the nanoparticles appears to be inversely proportional to the drug:CS ratio. An XRD study proves that TQ dispersed in the nanoparticles changes its form from crystalline to amorphous. This was further confirmed by differential scanning calorimetry thermography. The flat thermogram of the nanoparticle data indicated that TQ formed a molecular dispersion within the nanoparticles. Optimized nanoparticles were evaluated further with the help of scintigraphy imaging, which ascertains the uptake of drug into the brain. Based on maximum concentration, time-to-maximum concentration, area-under-curve over 24 hours, and elimination rate constant, intranasal TQ-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. PMID:23180965

  14. Chitosan/siRNA Nanoparticles Targeting Cyclooxygenase Type 2 Attenuate Unilateral Ureteral Obstruction-induced Kidney Injury in Mice

    PubMed Central

    Yang, Chuanxu; Nilsson, Line; Cheema, Muhammad Umar; Wang, Yan; Frøkiær, Jørgen; Gao, Shan; Kjems, Jørgen; Nørregaard, Rikke

    2015-01-01

    Cyclooxygenase type 2 (COX-2) plays a predominant role in the progression of kidney injury in obstructive nephropathy. The aim of this study was to test the efficacy of chitosan/small interfering RNA (siRNA) nanoparticles to knockdown COX-2 specifically in macrophages to prevent kidney injury induced by unilateral ureteral obstruction (UUO). Using optical imaging techniques and confocal microscopy, we demonstrated that chitosan/siRNA nanoparticles accumulated in macrophages in the obstructed kidney. Consistent with the imaging data, the obstructed kidney contained a higher amount of siRNA and macrophages. Chitosan-formulated siRNA against COX-2 was evaluated on RAW macrophages demonstrating reduced COX-2 expression and activity after LPS stimulation. Injection of COX-2 chitosan/siRNA nanoparticles in mice subjected to three-day UUO diminished the UUO-induced COX-2 expression. Likewise, macrophages in the obstructed kidney had reduced COX-2 immunoreactivity, and histological examination showed lesser tubular damage in COX-2 siRNA-treated UUO mice. Parenchymal inflammation, assessed by tumor necrosis factor-alpha (TNF-?) and interleukin 6 mRNA expression, was attenuated by COX-2 siRNA. Furthermore, treatment with COX-2 siRNA reduced heme oxygenase-1 and cleaved caspase-3 in UUO mice, indicating lesser oxidative stress and apoptosis. Our results demonstrate a novel strategy to prevent UUO-induced kidney damage by using chitosan/siRNA nanoparticles to knockdown COX-2 specifically in macrophages. PMID:25553102

  15. Intracellular siRNA delivery dynamics of integrin-targeted, PEGylated chitosan-poly(ethylene imine) hybrid nanoparticles: A mechanistic insight.

    PubMed

    Ragelle, Héloïse; Colombo, Stefano; Pourcelle, Vincent; Vanvarenberg, Kevin; Vandermeulen, Gaëlle; Bouzin, Caroline; Marchand-Brynaert, Jacqueline; Feron, Olivier; Foged, Camilla; Préat, Véronique

    2015-08-10

    Integrin-targeted nanoparticles are promising for the delivery of small interfering RNA (siRNA) to tumor cells or tumor endothelium in cancer therapy aiming at silencing genes essential for tumor growth. However, during the process of optimizing and realizing their full potential, it is pertinent to gain a basic mechanistic understanding of the bottlenecks existing for nanoparticle-mediated intracellular delivery. We designed ?v?3 integrin-targeted nanoparticles by coupling arginine-glycine-aspartate (RGD) or RGD peptidomimetic (RGDp) ligands to the surface of poly(ethylene glycol) (PEG) grafted chitosan-poly(ethylene imine) hybrid nanoparticles. The amount of intracellular siRNA delivered by ?v?3-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 transcription quantitative polymerase chain reaction (RT-qPCR) approach. Data demonstrated that the internalization of ?v?3-targeted nanoparticles was highly dependent on the surface concentration of the ligand. Above a certain threshold concentration, the use of targeted nanoparticles provided a two-fold increase in the number of siRNA copies/cell, subsequently resulting in as much as 90% silencing of EGFP at well-tolerated carrier concentrations. In contrast, non-targeted nanoparticles mediated low levels of gene silencing, despite relatively high intracellular siRNA concentrations, indicating 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 a more complete understanding of the delivery mechanism that can facilitate the future design of efficient siRNA delivery systems. PMID:25989603

  16. Enhanced drug-loading and therapeutic efficacy of hydrotropic oligomer-conjugated glycol chitosan nanoparticles for tumor-targeted paclitaxel delivery.

    PubMed

    Koo, Heebeom; Min, Kyung Hyun; Lee, Sang Cheon; Park, Jae Hyung; Park, Kinam; Jeong, Seo Young; Choi, Kuiwon; Kwon, Ick Chan; Kim, Kwangmeyung

    2013-12-28

    Enhanced drug-loading and therapeutic efficacies are highly essential properties for nanoparticles as tumor-targeting drug carriers. Herein, we developed the glycol chitosan nanoparticles with hydrotropic oligomers (HO-CNPs) as a new tumor targeting drug delivery system. For enhancing drug-loading efficiency of paclitaxel in drug carriers, hydrotropic 2-(4-(vinylbenzyloxy)-N,N-diethylnicotinamide) (VBODENA-COOH) oligomers, that were used for enhancing the aqueous solubility of paclitaxel, were directly conjugated to glycol chitosan polymers. The amphiphilic conjugates readily formed nanoparticle structure (average size=302 ± 22 nm) in aqueous condition. Water-insoluble paclitaxel (PTX) was readily encapsulated into HO-CNPs with a high drug-loading amount up to 24.2 wt.% (2.4 fold higher than other polymeric nanoparticles) by a simple dialysis method. The PTX encapsulated HO-CNPs (PTX-HO-CNPs; average size=343 ± 12 nm) were very stable in aqueous media up to 50 days. Also, PTX-HO-CNPs presented rapid cellular uptake and lower cytotoxicity in cell culture system, compared to Cremophor EL/ethanol formulation of PTX. In tumor-bearing mice, the extravasation and accumulation of PTX-HO-CNPs in tumor tissue were precisely observed by intravital fluorescence imaging techniques. Furthermore, PTX-HO-CNPs showed the higher therapeutic efficacy, compared to Abraxane®, a commercialized PTX-formulation. These overall results demonstrate its potential as a new nano-sized PTX carrier for cancer treatment. PMID:24035978

  17. Carboxymethyl chitosan-folic acid-conjugated Fe3O4@SiO2 as a safe and targeting antitumor nanovehicle in vitro

    PubMed Central

    2014-01-01

    A synthetic method to prepare a core-shell-structured Fe3O4@SiO2 as a safe nanovehicle for tumor cell targeting has been developed. Superparamagnetic iron oxide is encapsulated inside nonporous silica as the core to provide magnetic targeting. Carboxymethyl chitosan-folic acid (OCMCS-FA) synthesized through coupling folic acid (FA) with OCMCS is then covalently linked to the silica shell and renders new and improved functions because of the original biocompatible properties of OCMCS and the targeting efficacy of FA. Cellular uptake of the nanovehicle was assayed by confocal laser scanning microscope using rhodamine B (RB) as a fluorescent marker in HeLa cells. The results show that the surface modification of the core-shell silica nanovehicle with OCMCS-FA enhances the internalization of nanovehicle to HeLa cells which over-express the folate receptor. The cell viability assay demonstrated that Fe3O4@SiO2-OCMCS-FA nanovehicle has low toxicity and can be used as an eligible candidate for drug delivery system. These unique advantages make the prepared core-shell nanovehicle promising for cancer-specific targeting and therapy. PMID:24667013

  18. Galactosylated trimethyl chitosan-cysteine nanoparticles loaded with Map4k4 siRNA for targeting activated macrophages.

    PubMed

    Zhang, Jing; Tang, Cui; Yin, Chunhua

    2013-05-01

    Galactosylated trimethyl chitosan-cysteine (GTC) nanoparticles (NPs) were developed for oral delivery of a mitogen-activated protein kinase kinase kinase kinase 4 (Map4k4) siRNA (siMap4k4) to the activated macrophages for treatment of dextran sulfate sodium (DSS)-induced ulcerative colitis (UC). siRNA loaded GTC NPs were prepared based on ionic gelation of GTC with anionic crosslinkers (tripolyphosphate (TPP) or hyaluronic acid (HA)). The types of crosslinkers involved in GTC NPs significantly affected their physicochemical characteristics. GTC/TPP NPs with smaller particle size and lower zeta potential possessed superior structural stability in gastrointestinal environment compared to GTC/HA NPs. Cellular uptake of GTC/TPP NPs in activated macrophages was significantly enhanced compared to trimethyl chitosan-cysteine (TC)/TPP NPs owing to galactose receptor-mediated endocytosis. The in vitro and in vivo gene knockdown measurement showed that siMap4k4 loaded GTC/TPP NPs effectively inhibited TNF-? production, which remarkably outperformed siMap4k4 loaded TC/TPP NPs. Compared to TC/TPP NPs, GTC/TPP NPs more efficiently promoted the distribution of siRNA in ulcerative colon following oral administration. Daily oral administration of GTC/TPP NPs containing siMap4k4 significantly improved DSS-induced body weight loss, colon length shortening, and increase of myeloperoxidase activity. This study would provide an effective approach for oral siRNA delivery in the treatment of inflammatory bowel diseases. PMID:23419643

  19. Drug/Dye-Loaded, Multifunctional PEG-Chitosan-Iron Oxide Nanocomposites for Methotraxate Synergistically Self-Targeted Cancer Therapy and Dual Model Imaging.

    PubMed

    Lin, Jinyan; Li, Yang; Li, Yanxiu; Wu, Hongjie; Yu, Fei; Zhou, Shuifan; Xie, Liya; Luo, Fanghong; Lin, Changjian; Hou, Zhenqing

    2015-06-10

    Multifunctional nanocomposites hold great potential to integrate therapeutic and diagnostic functions into a single nanoscale structure. In this paper, we prepared the MTX-PEG-CS-IONPs-Cy5.5 nanocomposites by functionalizing the surface of chitosan-decorated iron oxide nanoparticles (CS-IONPs) with polyethylene glycolated methotraxate (MTX-PEG) and near-infrared fluorescent cyanin dye (Cy5.5). A clinically useful PEGylated anticancer prodrug, MTX-PEG, was also developed as a tumor cell-specific targeting ligand for self-targeted cancer treatment. In such nanocomposites, the advantage was that the orthogonally functionalized, self-targeted MTX-PEG-CS-IONPs-Cy5.5 can synergistically combine an early phase selective tumor-targeting efficacy with a late-phase cancer-killing effect, which was also confirmed by dual model (magnetic resonance and fluorescence) imaging. Furthermore, with the aids of the folate (FA) receptor-mediated endocytosis (able to turn cellular uptake "off" in normal cells and "on" in cancer cells) and pH/intracellular protease-mediated hydrolyzing peptide bonds (able to turn drug release "off" in systemic circulation and "on" inside endo/lysosomes), the MTX-PEG-CS-IONPs-Cy5.5 could deliver MTX to FA receptors-overexpressed cancer cells, showing the improved anticancer activity with the reduced side effects. Together, the MTX-PEG-CS-IONPs-Cy5.5 could act as a highly convergent, flexible, and simplified system for dual model imaging and synergistically self-targeted cancer therapy, holding great promise for versatile biomedical applications in future. PMID:25978458

  20. Process optimization for the preparation of oligomycin-loaded folate-conjugated chitosan nanoparticles as a tumor-targeted drug delivery system using a two-level factorial design method

    PubMed Central

    Zu, Yuangang; Zhao, Qi; Zhao, Xiuhua; Zu, Shuchong; Meng, Li

    2011-01-01

    Oligomycin-A (Oli-A), an anticancer drug, was loaded to the folate (FA)-conjugated chitosan as a tumor-targeted drug delivery system for the purpose of overcoming the nonspecific targeting characteristics and the hydrophobicity of the compound. The two-level factorial design (2-LFD) was applied to modeling the preparation process, which was composed of five independent variables, namely FA-conjugated chitosan (FA-CS) concentration, Oli-A concentration, sodium tripolyphosphate (TPP) concentration, the mass ratio of FA-CS to TPP, and crosslinking time. The mean particle size (MPS) and the drug loading rate (DLR) of the resulting Oli-loaded FA-CS nanoparticles (FA-Oli-CSNPs) were used as response variables. The interactive effects of the five independent variables on the response variables were studied. The characteristics of the nanoparticles, such as amount of FA conjugation, drug entrapment rate (DER), DLR, surface morphology, and release kinetics properties in vitro were investigated. The FA-Oli-CSNPs with MPS of 182.6 nm, DER of 17.3%, DLR of 58.5%, and zeta potential (ZP) of 24.6 mV were obtained under optimum conditions. The amount of FA conjugation was 45.9 mg/g chitosan. The FA-Oli-CSNPs showed sustained-release characteristics for 576 hours in vitro. The results indicated that FA-Oli-CSNPs obtained as a targeted drug delivery system could be effective in the therapy of leukemia in the future. PMID:22267927

  1. Targeted siRNA delivery by anti-HER2 antibody-modified nanoparticles of mPEG-chitosan diblock copolymer.

    PubMed

    Wang, Yiyi; Liu, Peifeng; Du, Jing; Sun, Ying; Li, Fenghua; Duan, Yourong

    2013-01-01

    This study aims to determine the specificity of anti-human epidermal growth factor receptor antibody (anti-HER2) modified monomethoxy polyethylene glycol-chitosan (mPEG-CS) nanoparticles (anti-HER2/mPEG-CS NPs) in delivering small interfering RNA (siRNA) to the human epidermal growth factor receptor 2 (HER2) positive cancer cells. Physicochemical properties of the siRNA-loaded anti-HER2/mPEG-CS NPs (anti-HER2/mPEG-CS-siRNA NPs), including size, surface charge, siRNA encapsulation efficiency, and in vitro release profile of siRNA from NPs, were characterized by particle size and zeta potential analyzer, and ultraviolet-visible spectrophotometer. MTT assay was used to study the in vitro cytotoxicity of the NPs. Fluorescent microscope and flow cytometer analysis results showed that anti-HER2/mPEG-CS-siRNA NPs had much efficient delivery of siRNA than the siRNA alone, Lipofectamine-siRNA complexes and mPEG-CS-siRNA NPs. These results demonstrated that anti-HER2/mPEG-CS-siRNA NPs had great potential applications as a targeted strategy for siRNA delivery. PMID:23713424

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

    PubMed

    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 ?g 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. PMID:24958702

  3. Folate-mediated targeted and intracellular delivery of paclitaxel using a novel deoxycholic acid-O-carboxymethylated chitosan–folic acid micelles

    PubMed Central

    Wang, Feihu; Chen, Yuxuan; Zhang, Dianrui; Zhang, Qiang; Zheng, Dandan; Hao, Leilei; Liu, Yue; Duan, Cunxian; Jia, Lejiao; Liu, Guangpu

    2012-01-01

    Background A critical disadvantage for successful chemotherapy with paclitaxel (PTX) is its nontargeting nature to cancer cells. Folic acid has been employed as a targeting ligand of various anticancer agents to increase their cellular uptake within target cells since the folate receptor is overexpressed on the surface of such tumor cells. In this study, a novel biodegradable deoxycholic acid-O-carboxymethylated chitosan–folic acid conjugate (DOMC-FA) was used to form micelles for encapsulating the anticancer drug PTX. Methods and results The drug-loading efficiency, encapsulation efficiency, in vitro drug release and physicochemical properties of PTX-loaded micelles were investigated in detail. In vitro cell culture studies were carried out in MCF-7 cells, a human breast carcinoma cell line, with folate receptor overexpressed on its surface. An increased level of uptake of folate-conjugated micelles compared to plain micelles in MCF-7 cells was observed, and the enhanced uptake of folate-micelles mainly on account of the effective process of folate receptor-mediated endocytosis. The MTT assay, morphological changes, and apoptosis test implied that the folate-conjugated micelles enhanced the cell death by folate-mediated active internalization, and the cytotoxicity of the FA-micellar PTX (DOMC-FA/PTX) to cancer cells was much higher than micelles without folate (DOMC/PTX) or the commercially available injectable preparation of PTX (Taxol). Conclusion Results indicate that the PTX-loaded DOMC-FA micelle is a successful anticancertargeted drug-delivery system for effective cancer chemotherapy. PMID:22287842

  4. Bioinspired Titanium Drug Eluting Platforms Based on a Poly-?-cyclodextrin-Chitosan Layer-by-Layer Self-Assembly Targeting Infections.

    PubMed

    Pérez-Anes, Alexandra; Gargouri, Myriem; Laure, William; Van Den Berghe, Hélène; Courcot, Elisabeth; Sobocinski, Jonathan; Tabary, Nicolas; Chai, Feng; Blach, Jean-François; Addad, Ahmed; Woisel, Patrice; Douroumis, Dennis; Martel, Bernard; Blanchemain, Nicolas; Lyskawa, Joël

    2015-06-17

    In the field of implantable titanium-based biomaterials, infections and inflammations are the most common forms of postoperative complications. The controlled local delivery of therapeutics from implants through polyelectrolyte multilayers (PEMs) has recently emerged as a versatile technique that has shown great promise in the transformation of a classical medical implant into a drug delivery system. Herein, we report the design and the elaboration of new biodegradable multidrug-eluting titanium platforms based on a polyelectrolyte multilayer bioactive coating that target infections. These systems were built up in mild conditions according to the layer-by-layer (L-b-L) assembly and incorporate two biocompatible polysaccharides held together through electrostatic interactions. A synthetic, negatively charged ?-cyclodextrin-based polymer (PCD), well-known for forming stable and reversible complexes with hydrophobic therapeutic agents, was exploited as a multidrug reservoir, and chitosan (CHT), a naturally occurring, positively charged polyelectrolyte, was used as a barrier for controlling the drug delivery rate. These polyelectrolyte multilayer films were strongly attached to the titanium surface through a bioinspired polydopamine (PDA) film acting as an adhesive first layer and promoting the robust anchorage of PEMs onto the biomaterials. Prior to the multilayer film deposition, the interactions between both oppositely charged polyelectrolytes, as well the multilayer growth, were monitored by employing surface plasmon resonance (SPR). Several PEMs integrating 5, 10, and 15 bilayers were engineered using the dip coating strategy, and the polyelectrolyte surface densities were estimated by colorimetric titrations and gravimetric analyses. The morphologies of these multilayer systems, as well as their naturally occurring degradation in a physiological medium, were investigated by scanning electron microscopy (SEM), and their thicknesses were measured by means of profilometry and ellipsometry studies. Finally, the ability of the coated titanium multilayer devices to act as a drug-eluting system and to treat infections was validated with gentamicin, a relevant water-soluble antibiotic commonly used in medicine due to its broad bactericidal spectrum. PMID:25992843

  5. Antibacterial action of chitosan

    Microsoft Academic Search

    N. R. Sudarshan; D. G. Hoover; D. Knorr

    1992-01-01

    The antibacterial action of chitosan hydroglutamate (CH), chitosan lactate (CL) and chitosan derived from fungal mycelia was examined against both gram?negative and gram?positive bacteria. Plate counts indicated inactivation rates of one? to five?log?cycles within one hour. Fungal chitosan had significantly less antibiotic effect than CH and CL. The antibacterial action of CH and CL was very similar and shown to

  6. Effect of HPMC - E15 LV premium polymer on release profile and compression characteristics of chitosan/ pectin colon targeted mesalamine matrix tablets and in vitro study on effect of pH impact on the drug release profile.

    PubMed

    Newton, A M J; Lakshmanan, Prabakaran

    2014-04-01

    The study was designed to investigate the in vitro dissolution profile and compression characteristics of colon targeted matrix tablets prepared with HPMC E15 LV in combination with pectin and Chitosan. The matrix tablets were subjected to two dissolution models in various simulated fluids such as pH 1.2, 6, 6.8, 7.2, 5.5. The fluctuations in colonic pH conditions during IBD (inflammatory bowel disease) and the nature of less fluid content in the colon may limit the expected drug release in the polysaccharide-based matrices when used alone. The Hydrophilic hydroxyl propyl methylcellulose ether premium polymer (HPMC E15 LV) of low viscosity grade was used in the formulation design, which made an excellent modification in physical and compression characteristics of the granules. The release studies indicated that the prepared matrices could control the drug release until the dosage form reaches the colon and the addition HPMC E15 LV showed the desirable changes in the dissolution profile by its hydrophilic nature since the colon is known for its less fluid content. The hydrophilic HPMC E15 LV allowed the colonic fluids to enter into the matrix and confirmed the drug release at the target site from a poorly water soluble polymer such as Chitosan and also from water soluble Pectin. The dramatic changes occurred in the drug release profile and physicochemical characteristics of the Pectin, Chitosan matrix tablets when a premium polymer HPMC E15 LV added in the formulation design in the optimized concentration. Various drug release mechanisms used for the examination of drug release characteristics. Drug release followed the combined mechanism of diffusion, erosion, swelling and polymer entanglement. In recent decade, IBD attracts many patents in novel treatment methods by using novel drug delivery systems. PMID:24597626

  7. Chitosan Microspheres in Novel Drug Delivery Systems

    PubMed Central

    Mitra, Analava; Dey, Baishakhi

    2011-01-01

    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. PMID:22707817

  8. Chitosan-Modified Graphene Electrodes for DNA Mutation Analysis

    PubMed Central

    Alwarappan, Subbiah; Cissell, Kyle; Dixit, Suraj; Mohapatra, Shyam; Li, Chen-Zhong

    2012-01-01

    Graphene has remarkable electrochemical properties that make it an ideal material for constructing biosensors,however it has not been explored for DNA biosensing. Herein, we report on a chitosan-modified graphene platform for the electrochemical detection of changes in DNA sequences. For this purpose, graphene synthesized chemically and characterized by Raman spectroscopy and Transmission electron microscopy, was covalently modified with positively charged chitosan to facilitate the immobilization of a single-stranded DNA `capture' oligonucleotide. The covalent attachment of chitosan to graphene was confirmed by FT-IR spectroscopy and then the capture DNA was immobilized on to the chitosan modified graphene electrode. Then, the target DNA (complementary or mismatched `mutant' DNA) was applied to the electrode and cyclic voltammetry was performed. The results of the voltammetric experiments indicate that the chitosan modified graphene electrodes immobilized with ssDNA+complementary DNA exhibit a significantly higher magnitude of redox peak current than the chitosan modified graphene electrodes immobilized with the non-complementary mutant DNAs. Together, these results demonstrate that the chitosan-graphene platform provides a rapid, stable and sensitive detection of mismatched DNA and has the potential to be used for point-of-care diagnostic tests for specific DNA mutations associated with disease conditions. PMID:23472058

  9. Chitosan in Plant Protection

    PubMed Central

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

    2010-01-01

    Chitin and chitosan are naturally-occurring compounds that have potential in agriculture with regard to controlling plant diseases. These molecules were shown to display toxicity and inhibit fungal growth and development. They were reported to be active against viruses, bacteria and other pests. Fragments from chitin and chitosan are known to have eliciting activities leading to a variety of defense responses in host plants in response to microbial infections, including the accumulation of phytoalexins, pathogen-related (PR) proteins and proteinase inhibitors, lignin synthesis, and callose formation. Based on these and other proprieties that help strengthen host plant defenses, interest has been growing in using them in agricultural systems to reduce the negative impact of diseases on yield and quality of crops. This review recapitulates the properties and uses of chitin, chitosan, and their derivatives, and will focus on their applications and mechanisms of action during plant-pathogen interactions. PMID:20479963

  10. Antimicrobial and mechanical properties of ?-cyclodextrin inclusion with essential oils in chitosan films.

    PubMed

    Sun, Xiuxiu; Sui, Siyao; Ference, Christopher; Zhang, Yifan; Sun, Shi; Zhou, Ninghui; Zhu, Wenjun; Zhou, Kequan

    2014-09-01

    Chitosan films incorporated with various concentrations of the complex of ?-cyclodextrin and essential oils (?-CD/EO) were prepared and investigated for antimicrobial, mechanical, and physical properties. Four bacterial strains that commonly contaminate food products were chosen as target bacteria to evaluate the antimicrobial activity of the prepared films. The incorporation of ?-CD/EO significantly increased the antimicrobial activities of the chitosan films against Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, and Listeria monocytogenes. It was also found that tensile strength (TS) of chitosan film was significantly increased with the incorporation of the ?-cyclodextrin and 0.75% essential oils complex. The elongation at break (EB) decreased with the increasing concentrations of essential oils. Inclusion of the complex of ?-cyclodextrin and 0.25% essential oils also significantly decreased water vapor permeability (WVP) of chitosan films. Our results suggest that chitosan films containing ?-CD/EO could be used as active food-packaging material. PMID:25141280

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

    PubMed

    Gordon, Sarah; Saupe, Anne; McBurney, Warren; Rades, Thomas; Hook, Sarah

    2008-12-01

    In this work the potential of chitosan nanoparticles (CNP) and thermosensitive chitosan hydrogels as particulate and sustained release vaccine delivery systems was investigated. CNP and chitosan hydrogels were prepared, loaded with the model protein antigen ovalbumin (OVA) and characterised. The immunostimulatory capacity of these vaccine delivery systems was assessed in-vitro and in-vivo. Particle sizing measurements and SEM images showed that optimised OVA-loaded CNP had a size of approximately 200 nm, a polydispersity index < 0.2, and a positive zeta-potential of approximately 18 mV. The amount of OVA adsorbed onto CNP was high with an adsorption efficacy of greater than 96%. Raman spectroscopy indicated conformational changes of OVA when adsorbed onto the surface of CNP. Uptake of the dispersions and immunological activation of murine dendritic cells in-vitro could be demonstrated. Investigation 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 < 10% of total protein being released after 10 days. The slow release from gel formulations may be explained by the strong interactions of the protein with chitosan. While OVA-loaded CNP showed no significant immunogenicity, formulations of OVA in chitosan gel were able to stimulate both cell-mediated and humoral immunity in-vivo. PMID:19000363

  12. Magnetic and fluorescent multifunctional chitosan nanoparticles as a smart drug delivery system

    Microsoft Academic Search

    Linlin Li; Dong Chen; Yanqi Zhang; Zhengtao Deng; Xiangling Ren; Xianwei Meng; Fangqiong Tang; Jun Ren; Lin Zhang

    2007-01-01

    An innovative drug delivery system based on magnetic and fluorescent multifunctional chitosan nanoparticles was developed, which combined magnetic targeting, fluorescent imaging and stimulus-responsive drug release properties into one drug delivery system. Water-soluble superparamagnetic Fe3O4 nanoparticles, CdTe quantum dots (QDs) and pharmaceutical drugs were simultaneously incorporated into chitosan nanoparticles; cross-linking the composite particles with glutaraldehyde tailored their size, morphology, surface properties

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

    PubMed Central

    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

  14. The coagulation characteristics of humic acid by using acid-soluble chitosan, water-soluble chitosan, and chitosan coagulant mixtures.

    PubMed

    Chen, Chih-Yu; Wu, Chung-Yu; Chung, Ying-Chien

    2015-05-01

    Chitosan is a potential substitute for traditional aluminium salts in water treatment systems. This study compared the characteristics of humic acid (HA) removal by using acid-soluble chitosan, water-soluble chitosan, and coagulant mixtures of chitosan with aluminium sulphate (alum) or polyaluminium chloride (PACl). In addition, we evaluated their respective coagulation efficiencies at various coagulant concentrations, pH values, turbidities, and hardness levels. Furthermore, we determined the size and settling velocity of flocs formed by these coagulants to identify the major factors affecting HA coagulation. The coagulation efficiency of acid- and water-soluble chitosan for 15?mg/l of HA was 74.4% and 87.5%, respectively. The optimal coagulation range of water-soluble chitosan (9-20?mg/l) was broader than that of acid-soluble chitosan (4-8?mg/l). Notably, acid-soluble chitosan/PACl and water-soluble chitosan/alum coagulant mixtures exhibited a higher coagulation efficiency for HA than for PACl or alum alone. Furthermore, these coagulant mixtures yielded an acceptable floc settling velocity and savings in both installation and operational expenses. Based on these results, we confidently assert that coagulant mixtures with a 1:1 mass ratio of acid-soluble chitosan/PACl and water-soluble chitosan/alum provide a substantially more cost-effective alternative to using chitosan alone for removing HA from water. PMID:25362971

  15. Chitosan glucose complex – A novel food preservative

    Microsoft Academic Search

    Sweetie R. Kanatt; Ramesh Chander; Arun Sharma

    2008-01-01

    Chitosan glucose complex (CGC), a modified form of chitosan was prepared by heating chitosan with glucose. Fluorescence and the browning reaction of CGC indicated the presence of the Maillard reaction product (MRP). CGC showed excellent antioxidant activity while chitosan or glucose alone did not have any significant activity (p<0.05). The IC50 value of CGC for DPPH radical scavenging was 51.1?g\\/ml.

  16. Separation of Chitosan from Penicillium Chrysogenum Mycelium and its Applications

    Microsoft Academic Search

    Tan Tianwei; Wang Binwu; Shi Xinyuan

    2002-01-01

    A process to separate chitosan from Penicillium chrysogenum mycelium was developed. Alkaline treatment and acetic acid extraction were used for deacetylating chitin to chitosan. The molecular weight of the chitosan was 3.6 × 104 and the degree of deacetylation was 84%. Analysis indicated that the chitosan from Penicillium chrysogenum mycelium was similar to that obtained from shrimp. The chitosan from

  17. Cellular Processes and Pathways That Protect Saccharomyces cerevisiae Cells against the Plasma Membrane-Perturbing Compound Chitosan? †

    PubMed Central

    Zakrzewska, Anna; Boorsma, Andre; Delneri, Daniela; Brul, Stanley; Oliver, Stephen G.; Klis, Frans M.

    2007-01-01

    Global fitness analysis makes use of a genomic library of tagged deletion strains. We used this approach to study the effect of chitosan, which causes plasma membrane stress. The data were analyzed using T-profiler, which was based on determining the sensitivities of groups of deletion strains to chitosan, as defined by Gene Ontology (GO) and by genomic synthetic lethality screens, in combination with t statistics. The chitosan-hypersensitive groups included a group of deletion strains characterized by a defective HOG (high-osmolarity glycerol) signaling pathway, indicating that the HOG pathway is required for counteracting chitosan-induced stress. Consistent with this, activation of this pathway in wild-type cells by hypertonic conditions offered partial protection against chitosan, whereas hypotonic conditions sensitized the cells to chitosan. Other chitosan-hypersensitive groups were defective in RNA synthesis and processing, actin cytoskeleton organization, protein N-glycosylation, ergosterol synthesis, endocytosis, or cell wall formation, predicting that these cellular functions buffer the cell against the deleterious effect of chitosan. These predictions were supported by showing that tunicamycin, miconazole, and staurosporine (which target protein N-glycosylation, ergosterol synthesis, and the cell wall integrity pathway, respectively) sensitized Saccharomyces cerevisiae cells to chitosan. Intriguingly, the GO-defined group of deletion strains belonging to the “cytosolic large ribosomal subunit” was more resistant to chitosan. We propose that global fitness analysis of yeast in combination with T-profiler is a powerful tool to identify specific cellular processes and pathways that are required for survival under stress conditions. PMID:17259547

  18. Environmental applications of chitosan and its derivatives.

    PubMed

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

    2015-01-01

    Chitosan originates from the seafood processing industry and is one of the most abundant of bio-waste materials. Chitosan is a by-product of the alkaline deacetylation process of chitin. Chemically, chitosan is a polysaccharide that is soluble in acidic solution and precipitates at higher pHs. It has great potential for certain environmental applications, such as remediation of organic and inorganic contaminants, including toxic metals and dyes in soil, sediment and water, and development of contaminant sensors. Traditionally, seafood waste has been the primary source of chitin. More recently, alternative sources have emerged such as fungal mycelium, mushroom and krill wastes, and these new sources of chitin and chitosan may overcome seasonal supply limitations that have existed. The production of chitosan from the above-mentioned waste streams not only reduces waste volume, but alleviates pressure on landfills to which the waste would otherwise go. Chitosan production involves four major steps, viz., deproteination, demineralization, bleaching and deacetylation. These four processes require excessive usage of strong alkali at different stages, and drives chitosan's production cost up, potentially making the application of high-grade chitosan for commercial remediation untenable. Alternate chitosan processing techniques, such as microbial or enzymatic processes, may become more cost-effective due to lower energy consumption and waste generation. Chitosan has proved to be versatile for so many environmental applications, because it possesses certain key functional groups, including - OH and -NH2 . However, the efficacy of chitosan is diminished at low pH because of its increased solubility and instability. These deficiencies can be overcome by modifying chitosan's structure via crosslinking. Such modification not only enhances the structural stability of chitosan under low pH conditions, but also improves its physicochemical characteristics, such as porosity, hydraulic conductivity, permeability, surface area and sorption capacity. Crosslinked chitosan is an excellent sorbent for trace metals especially because of the high flexibility of its structural stability. Sorption of trace metals by chitosan is selective and independent of the size and hardness of metal ions, or the physical form of chitosan (e.g., film, powder and solution). Both -OH and -NH2 groups in chitosan provide vital binding sites for complexing metal cations. At low pH, -NH3 + groups attract and coagulate negatively charged contaminants such as metal oxyanions, humic acids and dye molecules. Grafting certain functional molecules into the chitin structure improves sorption capacity and selectivity for remediating specific metal ions. For example, introducing sulfur and nitrogen donor ligands to chitosan alters the sorption preference for metals. Low molecular weight chitosan derivatives have been used to remediate metal contaminated soil and sediments. They have also been applied in permeable reactive barriers to remediate metals in soil and groundwater. Both chitosan and modified chitosan have been used to phytoremediate metals; however, the mechanisms by which they assist in mobilizing metals are not yet well understood. In addition, microbes have been used in combination with chitosan to remediate metals (e.g., Cu and Zn) in contaminated soils. Chitosan has also been used to remediate organic contaminants, such as oil-based wastewater, dyes, tannins, humic acids, phenols, bisphenoi-A, p-benzoquinone, organo-phosphorus insecticides, among others. Chitosan has also been utilized to develop optical and electrochemical sensors for in-situ detection of trace contaminants. In sensor technology, naturally-derived chitosan is used primarily as an immobilizing agent that results from its enzyme compatibility, and stabilizing effect on nanoparticles. Contaminant-sensing agents, such as enzymes, microbes and nanoparticles, have been homogeneously immobilized in chitosan gels by using coagulating (e.g., alginate, phosphate) or crosslinking agents (e.g., GA, ECH).

  19. Chitin, chitosan, and glycated chitosan regulate immune responses: the novel adjuvants for cancer vaccine.

    PubMed

    Li, Xiaosong; Min, Min; Du, Nan; Gu, Ying; Hode, Tomas; Naylor, Mark; Chen, Dianjun; Nordquist, Robert E; Chen, Wei R

    2013-01-01

    With the development of cancer immunotherapy, cancer vaccine has become a novel modality for cancer treatment, and the important role of adjuvant has been realized recently. Chitin, chitosan, and their derivatives have shown their advantages as adjuvants for cancer vaccine. In this paper, the adjuvant properties of chitin and chitosan were discussed, and some detailed information about glycated chitosan and chitosan nanoparticles was also presented to illustrate the trend for future development. PMID:23533454

  20. Chitosan as a macroaffinity ligand

    Microsoft Academic Search

    S. Teotia; R. Lata; M. N. Gupta

    2004-01-01

    (1) Chitosan was found to be a suitable macroaffinity ligand for affinity precipitation of chitinase from Neurospora crassa, cabbage and puffballs. (2) The activity recoveries of 85, 82 and 90% with concomitant fold purifications in terms of specific activities were 27, 15 and 30 with N. crassa, cabbage and puffballs and were obtained with affinity precipitation. These results were obtained

  1. Preparation and antimicrobial activity of hydroxypropyl chitosan

    Microsoft Academic Search

    Yanfei Peng; Baoqin Han; Wanshun Liu; Xiaojuan Xu

    2005-01-01

    Water-soluble hydroxypropyl chitosan (HPCS) derivatives with different degrees of substitution (DS) and weight-average molecular weight (Mw) were synthesized from chitosan and propylene epoxide under basic conditions. Their structure was characterized by IR spectroscopy, NMR spectroscopy, and elemental analysis, which showed that both the OH groups at C-6 and C-3 and the NH2 group of chitosan were alkylated. The DS value

  2. Flocculation of river silt using chitosan

    Microsoft Academic Search

    Ravi Divakaran; V. N. Sivasankara Pillai

    2002-01-01

    Flocculation of silt in river water using chitosan was studied in the pH range 4–9, and suspended solid concentrations in the range 20–80mg\\/L. Chitosan effectively reduces turbidity due to silt by flocculation and settling. Flocculation efficiency is very sensitive to pH, and reaches a maximum at pH 7. The optimal chitosan concentration required to effect flocculation is 0.5mg\\/L and is

  3. Megalin-Mediated Specific Uptake of Chitosan/siRNA Nanoparticles in Mouse Kidney Proximal Tubule Epithelial Cells Enables AQP1 Gene Silencing

    PubMed Central

    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. PMID:25157280

  4. Recent patents on food applications of chitosan.

    PubMed

    Vargas, Maria; González-Martínez, Chelo

    2010-06-01

    Chitosan is a natural polysaccharide that has become of great interest due to its multiple possible applications, which is a great challenge for both the scientific community and the food industry. Chitosan offers a wide range of food applications, including formation of biodegradable films and coatings, immobilization of enzymes, as an antimicrobial agent, and dietary supplement with hypocholesterolemic properties. The number of issued patents on the application of chitosan and its derivatives has been increasing steadily in the last decade. The present works reviews recent patents and important developments related to the use of chitosan in food industry. PMID:20653557

  5. Brain-Targeted Nasal Clonazepam Microspheres

    PubMed Central

    Shaji, J.; Poddar, A.; Iyer, S.

    2009-01-01

    Gelatin-chitosan mucoadhesive microspheres of clonazepam were prepared using the emulsion cross linking method. Mirospheres were evaluated using the in vitro and ex vivo drug release patterns. In vivo CNS drug distribution studies were carried out in rats by administering the clonazepam microspheres intra-nasally and clonazepam solution intravenously. From the drug levels in plasma and CSF, drug targeting index and drug targeting efficiency were calculated. Results obtained indicated that intranasally administered clonazepam microspheres resulted in higher brain levels with a drug targeting index of 2.12. Gelatin-chitosan cross linked mucoadhesive microspheres have the potential to be developed as a brain-targeted drug delivery system for clonazepam.

  6. Simple preparation of chitosan nanofibers from dry chitosan powder by the Star Burst system.

    PubMed

    Dutta, Ajoy Kumar; Kawamoto, Naoki; Sugino, Gaku; Izawa, Hironori; Morimoto, Minoru; Saimoto, Hiroyuki; Ifuku, Shinsuke

    2013-09-12

    Chitosan nanofibers were easily prepared from dry chitosan powder using the Star Burst system, which employs a high-pressure water jet system. Although the chitosan nanofibers became thinner as the number of Star Burst passes increased, the fiber thickness did not change significantly above 10 passes. Crystallinity and the chitosan nanofiber length decreased after extensive treatment due to the strong collision forces breaking the fibers. The mechanical properties and thermal expansion of the chitosan nanofiber sheets were improved by increasing the number of passes up to 10, but further treatment resulted in a deterioration of these properties. PMID:23911458

  7. Preparation of chitosan nanofibers from completely deacetylated chitosan powder by a downsizing process.

    PubMed

    Aklog, Yihun Fantahun; Dutta, Ajoy Kumar; Izawa, Hironori; Morimoto, Minoru; Saimoto, Hiroyuki; Ifuku, Shinsuke

    2015-01-01

    Chitosan nanofibers were easily prepared from fully deacetylated chitosan dry powder using a high-pressure waterjet system. From SEM observation, after 10 cycles of treatment, most of the chitosan had been reduced to homogeneous nanofibers measuring tens of nanometers. On the other hand, further mechanical treatment did not show a significant change. Relative crystallinity of chitosan nanofibers gradually decreased as the number of passes increased since high-pressure waterjet treatment damaged the crystalline region of chitosan nanofibers. The transmittance of the chitosan nanofiber slurry increased steeply, as the number of passes increased, indicating that the chitosan fibers were disintegrated effectively. Viscosity of chitosan nanofiber slurry also showed that the chitosan disintegrated well into nanofibers up to 10 passes. Above 10 passes, disintegration efficiency was saturated. The molecular weights of the nanofibers steeply decreased due to the depolymerization of chitosan by mechanical disintegration. The Young's modulus and tensile strength of chitosan nanofiber sheets were improved as the number of treatments increased, but further treatments deteriorated the tensile strength. PMID:25450540

  8. Synthesis and antibacterial activities of quaternary ammonium salt of chitosan

    Microsoft Academic Search

    Zhishen Jia; Dongfeng shen; Weiliang Xu

    2001-01-01

    Chitosan derivatives with quaternary ammonium salt, such as N,N,N-trimethyl chitosan, N–N-propyl-N,N-dimethyl chitosan and N-furfuryl-N,N-dimethyl chitosan were prepared using different 96% deacetylated chitosan of Mv 2.14×105, 1.9×104, 7.8×103. Amino groups on chitosan react with aldehydes to from a Schiff base intermediate. Quaternized chitosan were obtained by reaction of a Schiff base with methyl iodide. The yields, degree of quaternization and water-solubility

  9. Magnetic and fluorescent multifunctional chitosan nanoparticles as a smart drug delivery system

    NASA Astrophysics Data System (ADS)

    Li, Linlin; Chen, Dong; Zhang, Yanqi; Deng, Zhengtao; Ren, Xiangling; Meng, Xianwei; Tang, Fangqiong; Ren, Jun; Zhang, Lin

    2007-10-01

    An innovative drug delivery system based on magnetic and fluorescent multifunctional chitosan nanoparticles was developed, which combined magnetic targeting, fluorescent imaging and stimulus-responsive drug release properties into one drug delivery system. Water-soluble superparamagnetic Fe3O4 nanoparticles, CdTe quantum dots (QDs) and pharmaceutical drugs were simultaneously incorporated into chitosan nanoparticles; cross-linking the composite particles with glutaraldehyde tailored their size, morphology, surface properties and drug release behaviors. The system showed superparamagnetic and strong fluorescent properties, and was used as a controlled drug release vehicle, which showed pH-sensitive drug release over a long time. The composite magnetic and fluorescent chitosan nanoparticles are potential candidates as a smart drug delivery system.

  10. Antimicrobial Action of Water-Soluble ?-Chitosan against Clinical Multi-Drug Resistant Bacteria

    PubMed Central

    Park, Seong-Cheol; Nam, Joung-Pyo; Kim, Jun-Ho; Kim, Young-Min; Nah, Jae-Woon; Jang, Mi-Kyeong

    2015-01-01

    Recently, the number of patients infected by drug-resistant pathogenic microbes has increased remarkably worldwide, and a number of studies have reported new antibiotics from natural sources. Among them, chitosan, with a high molecular weight and ?-conformation, exhibits potent antimicrobial activity, but useful applications as an antibiotic are limited by its cytotoxicity and insolubility at physiological pH. In the present study, the antibacterial activity of low molecular weight water-soluble (LMWS) ?-chitosan (?1k, ?5k, and ?10k with molecular masses of 1, 5, and 10 kDa, respectively) and ?-chitosan (?1k, ?5k, and ?10k) was compared using a range of pathogenic bacteria containing drug-resistant bacteria isolated from patients at different pH. Interestingly, ?5k and ?10k exhibited potent antibacterial activity, even at pH 7.4, whereas only ?10k was effective at pH 7.4. The active target of ?-chitosan is the bacterial membrane, where the leakage of calcein is induced in artificial PE/PG vesicles, bacterial mimetic membrane. Moreover, scanning electron microscopy showed that they caused significant morphological changes on the bacterial surfaces. An in vivo study utilizing a bacteria-infected mouse model found that LMWS ?-chitosan could be used as a candidate in anti-infective or wound healing therapeutic applications. PMID:25867474

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

    PubMed Central

    Shi, Si-Feng; Jia, Jing-Fu; Guo, Xiao-Kui; Zhao, Ya-Ping; Chen, De-Sheng; Guo, Yong-Yuan; Cheng, Tao; Zhang, Xian-Long

    2012-01-01

    Background: 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. PMID:23118539

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

    PubMed

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

    2012-11-01

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

  13. Effect of chitosan content on gel content of epoxized natural rubber grafted with chitosan in latex form.

    PubMed

    Riyajan, Sa-Ad; Sukhlaaied, Wattana

    2013-04-01

    The epoxidized natural rubber (ENR) latex-g-chitosan (ENR-g-chitosan) was prepared in latex form using potassium persulphate as an initiator. Firstly, the reduction in molecular weight of chitosan was subjected to the addition of K2S2O8 at 70 °C for 15 min. The structure of the modified chitosan was characterized by ATR-FTIR. Secondarily, the influence of chitosan contents, reaction time, and temperature and K2S2O8 concentrations on the gel content of the modified ENR was investigated. The chemical structure of the ENR-g-chitosan was confirmed by (1)H-NMR and ATR-FTIR. The ether linkage of the ENR-g-chitosan was conformed at 1154 an 1089 cm(-1) by ATR-FTIR and 3.60 ppm by (1)H-NMR. The gel content of ENR-g-chitosan at 5% chitosan showed the highest value compared with other samples. But when chitosan increased from 5% to 10% or 20%, the gel content of ENR-g-chitosan dramatically decreased. The ENR-g-chitosan showed good thermal resistance due to incorporation of chitosan. The morphology of ENR-g-chitosan particle showed the core-shell structure observed by TEM. The optimum condition of grafting ENR with chitosan was found at 65°C for 3h of reaction time, ratio of ENR/chitosan at 9:1. PMID:23827540

  14. Hemostatic Agents Derived from Chitin and Chitosan

    Microsoft Academic Search

    Hyun Suk Whang; Wolff Kirsch; Yong H. Zhu; Cheng Z. Yang; Samuel M. Hudson

    2005-01-01

    A recent review detailing the role of new hemostatic agents for battlefield hemorrhage control describes the interest in and necessary specifications for such materials. As a consequence, the Defense Department authorized the development and use of three deployable and FDA approved hemostatic agents: Zeolite “Quikclot” and chitosanic “Hemcon” and the American Red Cross Fibrin Dressing. Although chitosan has a number

  15. The hypolipidemic activity of chitosan nanopowder prepared by ultrafine milling.

    PubMed

    Zhang, Wei; Zhang, Jiali; Jiang, Qixing; Xia, Wenshui

    2013-06-01

    The hypolipidemic activities of high and low molecular weights of chitosan nanopowders (HMW-chitosan-NP: 315 kDa; LMW-chitosan-NP: 51 kDa) prepared by ultrafine milling were evaluated in rats. The results showed that the hypolipidemic activity of chitosan nanopowder was better than ordinary chitosan, and LMW-chitosan-NP was superior to HMW-chitosan-NP in hypolipidimic activity. Compared with ordinary chitosan, chitosan nanopowder increased the fecal lipids and the activities of serum and liver lipoprotein lipase (LPL) and hepatic lipase (HL) of rats. Rats receiving LMW-chitosan-NP excreted less lipids in feces, but showed higher serum and liver LPL and HL activities compared with those fed HMW-chitosan-NP. These results suggested that compared with ordinary chitosan, the increased hypolipidemic activity of chitosan nanopowder might be attributed to its ability on increasing fecal lipid excretions and stimulating LPL and HL activities, and the better stimulation of LMW-chitosan-NP in activities of these lipases might help it to exceed HMW-chitosan-NP in hypolipidemic activity. PMID:23618297

  16. Insights into and relative effect of chitosan-H, chitosan-H-propolis, chitosan-H-propolis-nystatin and chitosan-H-nystatin on dentine bond strength

    PubMed Central

    Perchyonok, Victoria Tamara; Zhang, Shengmiao; Grobler, Sias R.; Oberholzer, Theunis G.

    2013-01-01

    Objective: The purpose of the study was to design and evaluate novel functional chitosan hydrogels (chitosan-H-propolis, chitosan-H-propolis-nystatin and chitosan-H-nystatin) by using the chitosan-H polymer as “dual function restorative materials”. Materials and Methods: The nystatin/antioxidant carrier gel was prepared by dispersion of the corresponding component in glycerol and 3% acetic acid with 5% chitosan gelling agent was then added to the dispersion with continuous mixing. The natural bio-adhesive functionalized chitosan hydrogels were combined with built in drug delivery system and bio-actives such as propolis in order to increase the dentin bond strength capacity and maintain therapeutic properties of the alternative drug delivery system. The surface morphology, release behaviors (physiological pH and also in acidic conditions), stability of nystatin:antioxidant:chitosan and the effect of the hydrogels on the shear bond strength of dentin were also evaluated. Statistical Analysis Used: Non-parametric ANOVA test was used to asses significance of higher shear bond values than dentine treated or not treated with phosphoric acid. Results: The release of both nystatin and propolis confer the added benefit of dual action of a functional therapeutic delivery when comparing the newly designed chitosan-based hydrogel restorative materials to commercially available nystatin alone. Neither the release of nystatin nor the antioxidant stability was affected by storage. Chitosan-H, chitosan-propolis, chitosan-nystatin and chitosan-nystatin-propolis treated dentine gives significantly (P < 0.05) higher shear bond values (P < 0.05) than dentine treated or not treated with phosphoric acid. Conclusion: The added benefits of their unique functionality involve increased dentin adhesive bond strengths (after 24 h and after 6 months) and positive influence on the nystatin release. Nystatin was a model therapeutic agent, evaluating the concept of using functional materials as carriers for pro-drugs as well as displaying a certain degree of defence mechanism for free radical damage of the novel functional drug delivery. Overall, there was an insignificant relapse in the shear bond strength after 6 months. PMID:24932114

  17. Synthesis of aligned hematite nanoparticles on chitosan-alginate films.

    PubMed

    Sreeram, Kalarical Janardhanan; Nidhin, Marimuthu; Nair, Balachandran Unni

    2009-07-01

    Iron oxide nanoparticles are being viewed with interest owing to the great potential they have in the biomedical applications like MRI contrast enhancement, targeted drug delivery, hyperthermia and recently in magnetic separation of cancer cells from the body. Templated synthesis has been considered ideal for synthesis of iron oxide nanoparticles as particles are attracted magnetically, in addition to usual flocculation through van der Waals attraction. Biological templates are attractive owing to their biocompatibility and the attractive porosity and surface chemistry that nature provides. Polysaccharides like chitosan and alginate have been employed in the synthesis of a polyion complex, which provided the active-binding sites for iron(II) ions in solution to bind. The natural organization of chitosan and alginate into a porous film has been exploited to synthesize spherical iron oxide nanoparticles through careful calcination of the iron(II) conjugate film. Our experiments indicate that the formed nanoparticles are highly crystalline, confirm to the hematite structure and have a superparamagnetic response with a low coercivity of 116Oe. Particles thus synthesized were highly monodisperse with hydrodynamic diameter of 1.8 nm. The symmetric porosity of the film translates into the synthesis of well-aligned nanoparticles of iron oxide. Compared to synthesis in solution, the film-assisted synthesis offered a greater degree of control over the particle size distribution pattern, with the chitosan-alginate template providing the needed spatial separation to prevent the aggregation due to magnetostatic coupling. Such hematite nanoparticles can either be used directly or converted to paramagnetic magnetite by reduction. Zeta potential measurements indicate highly stable nanoparticles, which can therefore be conjugated to cationic liposomes carrying drugs and magnetically guided to target sites. PMID:19303261

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

    PubMed Central

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

    2006-01-01

    Nanoparticles of ~10 nm in diameter made with chitosan or lactic acid-grafted chitosan were developed for high drug loading and prolonged drug release. A drug encapsulation efficiency of 92% and a release rate of 28% from chitosan nanoparticles over a 4-week period were demonstrated with bovine serum protein. To further increase drug encapsulation, prolong drug release, and increase chitosan solubility in solution of neutral pH, chitosan was modified with lactic acid by grafting D,L-lactic acid onto amino groups in chitosan without using a catalyst. The lactic acid-grafted chitosan nanoparticles demonstrated a drug encapsulation efficiency of 96% and a protein release rate of 15% over 4 weeks. With increased protein concentration, the drug encapsulation efficiency decreased and drug release rate increased. Unlike chitosan, which is generally soluble only in acid solution, the chitosan modified with lactic acid can be prepared from solutions of neutral pH, offering an additional advantage of allowing proteins or drugs to be uniformly incorporated in the matrix structure with minimal or no denaturization. PMID:17722534

  19. Direct compression properties of chitin and chitosan.

    PubMed

    Mir, Viviana García; Heinämäki, Jyrki; Antikainen, Osmo; Revoredo, Ofelia Bilbao; Colarte, Antonio Iraizoz; Nieto, Olga Maria; Yliruusi, Jouko

    2008-08-01

    Deformation and compaction properties of native amino poly-saccharides chitin and chitosan were studied and compared with those obtained with established pharmaceutical direct compression excipients. An instrumented single-punch tablet machine was used for tablet compaction. The following compression parameters were evaluated: a ratio of crushing strength and compression pressure, plasticity and elasticity factor (PF and EF), tensile strength and R-value. Chitin and chitosan were found to have a marked tendency to plastic deformation, and both showed a good compression behaviour compared with the other direct compression excipients including microcrystalline cellulose. It is concluded that chitin and chitosan are potential co-excipients for direct compression applications. PMID:18406116

  20. Effects of carboxymethyl chitosan on the blood system of rats

    SciTech Connect

    Fu, Dawei [College of Marine Life Sciences, Ocean University of China, Qingdao 266003 (China)] [College of Marine Life Sciences, Ocean University of China, Qingdao 266003 (China); Han, Baoqin, E-mail: baoqinh@ouc.edu.cn [College of Marine Life Sciences, Ocean University of China, Qingdao 266003 (China)] [College of Marine Life Sciences, Ocean University of China, Qingdao 266003 (China); Dong, Wen; Yang, Zhao; Lv, You; Liu, Wanshun [College of Marine Life Sciences, Ocean University of China, Qingdao 266003 (China)] [College of Marine Life Sciences, Ocean University of China, Qingdao 266003 (China)

    2011-04-29

    Highlights: {yields} We report, for the first time, the safety of carboxymethyl chitosan in blood system. {yields} CM-Chitosan has no significant effects on coagulation function of rats. {yields} CM-Chitosan has no significant effects on anticoagulation performance of rats. {yields} CM-Chitosan has no significant effects on fibrinolytic function of rats. {yields} CM-Chitosan has no significant effects on hemorheology of rats. -- Abstract: Carboxymethyl chitosan (CM-chitosan), a derivative of chitosan, was extensively studied in the biomedical materials field for its beneficial biological properties of hemostasis and stimulation of healing. However, studies examining the safety of CM-chitosan in the blood system are lacking. In this study CM-chitosan was implanted into the abdominal cavity of rats to determine blood indexes at different times and to evaluate the effects of CM-chitosan on the blood system of rats. Coagulation function was reflected by thrombin time (TT), prothrombin time (PT), activated partial thromboplatin time (APTT), fibrinogen (FIB) and platelet factor 4 (PF4) indexes; anti-coagulation performance was assessed by the index of antithrombinIII (ATIII); fibrinolytic function was reflected by plasminogen (PLG) and fibrin degradation product (FDP) indexes; and blood viscosity (BV) and plasma viscosity (PV) indexes reflected hemorheology. Results showed that CM-chitosan has no significant effects on the blood system of rats, and provides experimental basis for CM-chitosan to be applied in the field of biomedical materials.

  1. Chitosan-inducing hemorrhagic pneumonia in dogs

    Microsoft Academic Search

    S. Minami; M. Oh-oka; Y. Okamoto; K. Miyatake; A. Matsuhashi; Y. Shigemasa; Y. Fukumoto

    1996-01-01

    Various amounts of chitosan (10–200 mg\\/kg) were administered subcutaneously to dogs. Anorexia and mortality were observed in dogs given doses above 50 mg\\/ kg, and above 150 mg\\/kg, respectively. In hematologic findings leukocytosis and increasing of serum LDH2 and LDH3 isoenzymes were characteristic. From the findings of autopsy, severe hemorrhagic pneumonia was observed in all dead dogs. Chitosan causes lethal

  2. Heat-Induced Transfer of Protons from Chitosan to Glycerol Phosphate Produces Chitosan Precipitation and Gelation

    E-print Network

    Buschmann, Michael

    Precipitation and Gelation Marc Lavertu, Dominic Filion, and Michael D. Buschmann* Institute of Biomedical of gelation in chitosan-GP systems whereby heat induces transfer of protons from chitosan to glycerol in these dilute systems as a surrogate for gelation in concentrated systems. Measured temperatures

  3. Effect of chitosan molecular weight on rheological behavious of chitosan modified nanoclay at highly hydrated state

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effect of chitosan molecular weight (M(cs)) on the rheological properties of chitosan modified clay (CMCs) at highly hydrated state was investigated. With special emphasis on its effect on the thixotropy of CMCs, the structure recovery at rest after underwent a pre-shearing process was further perfo...

  4. [The use of chitosan to facilitate nerve regeneration].

    PubMed

    W?aszczuk, Adam; Pietrucha-Dutczak, Marita; Marcol, Wies?aw; Jedrzejowska-Szypu?ka, Halina; Lewin-Kowalik, Joanna

    2011-01-01

    Chitosan, a biopolymer derived from chitin, biocompatible, biodegradable and antibacterial, has many medical applications. For more than a decade scientists have been studying the influence of chitosan on facilitating regeneration of peripheral nerves and neurons of central nervous system in animal models. First clinical attempts have also commenced. Because of many modifications that can be applied to chitosan, e.g. combining with drugs, growth factors, nerve stem cells, and connecting with other biopolymers, this material seems very promising. In this article the authors present the results of worldwide performed experiments concerning the use of chitosan to facilitate nerve regeneration. This work contains description of experiments which used chitosan as: cell culture medium, drug carrier, chitosan tunnels, sponge, fibers, films, multichannel and multicomponent chitosan conduits, chitooligosaccharides and the influence of all chitosan forms listed above on regenerating neurons. PMID:22335146

  5. Radiation-induced degradation of carboxymethylated chitosan in aqueous solution

    Microsoft Academic Search

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

    2007-01-01

    Aqueous solutions of carboxymethylated chitosan (CM-chitosan) were radiated with ?-ray in various conditions. The degradations of CM-chitosan were faster in the presence of nitrous oxide or hydrogen peroxide, but it was inhibited obviously after adding isopropanol because of the changes of the concentration of hydroxyl radicals in above different conditions. The radiation chemical yields of CM-chitosan degradation were found to

  6. Activity of Chitosans in combination with antibiotics in Pseudomonas aeruginosa

    Microsoft Academic Search

    San Tin; Kishore R. Sakharkar; Chu Sing Lim; Meena K. Sakharkar

    2009-01-01

    Chitosan and its derivative water soluble Chitosan oligosaccharide are used in a variety of applications in pharmaceutical preparations. In this study, 2 wild (ATCC 15729 and PAO1) and 2 mutant strains (PT121 and PT149) of P. aeruginosa are investigated for drug-drug in- teractions in vitro. 10 antimicrobial agents (antibiotics) are combined with different degree of deacetylated Chitosans and Chitosan oligosaccharide.

  7. Chitosan-LiOH-urea aqueous solution--a novel water-based system for chitosan processing.

    PubMed

    Fan, Min; Hu, Qiaoling

    2009-05-12

    A solution of partially N-deacetylated chitosan in aqueous lithium hydroxide (LiOH)/urea was prepared successfully through a freeze-thawing process and the dissolution behavior was studied. The results indicated that chitosan can directly dissolve in LiOH/urea aqueous solution. LiOH mainly contributed to the breakage of intramolecular and intermolecular hydrogen bonds in chitosan. Urea, LiOH, and chitosan formed inclusion compound (IC) with urea as the IC host, and the LiOH-chitosan complex as the guest. Aqueous 4.8 wt% LiOH/8.0 wt% urea was verified to be the optimal solvent for chitosan. The results of rheology and viscosity characterizations revealed that chitosan/4.8 wt% LiOH/8.0 wt% urea aqueous solution was pseudoplastic fluid, and was more stable than the solution of chitosan in acetic acid at ambient temperature. PMID:19329109

  8. Forensic Fingerprint Enhancement using Bioadhesive Chitosan and Gold Nanoparticles

    Microsoft Academic Search

    Naveed Ul Islam; Kazi F. Ahmed; Abhilash Sugunan; Joydeep Dutta

    2007-01-01

    Detection of latent fingerprints using lipophilic and polycationic polymer chitosan has been explored. The gold nanoparticle deposition on chitosan treated latent fingerprints enhances contrast, making the fingerprint identification possible. Chitosan being the second most abundant natural polymer, this technique can be an inexpensive and efficient method for fingerprint enhancement and its subsequent detection. This simple technique has a potential of

  9. Free radical degradation of chitosan with potassium persulfate

    Microsoft Academic Search

    Shih-Chang Hsu; Trong-Ming Don; Wen-Yen Chiu

    2002-01-01

    A thermal dissociation initiator, potassium persulfate (KPS), is added to the chitosan solution at 70 °C; immediately, the solution viscosity and the molecular weight of chitosan decrease in a very short time. Size exclusion chromatography, nuclear magnetic resonance and electron spin resonance were used to study the degradation mechanism. A free radical degradation mechanism of chitosan by KPS is then proposed.

  10. Chitosan templated synthesis of porous metal oxide microspheres with filamentary nanostructures

    Microsoft Academic Search

    Abdelkrim El Kadib; Karine Molvinger; Thomas Cacciaguerra; Mosto Bousmina; Daniel Brunel

    2011-01-01

    This work describes a versatile strategy for fabricating highly porous and nanofibrous titania, zirconia, alumina and tin oxide. Taking advantage from chitosan polysaccharide microspheres as nano-assembling system during sol–gel mineralization of monomeric alkoxides and the beneficial effect of supercritical CO2 drying to avoid the collapse of the transient hybrid material network, all targeted metal oxides were created, after calcinations, as

  11. Electrochemical monitoring of indicator-free DNA hybridization by carbon nanotubes-chitosan modified disposable graphite sensors.

    PubMed

    Erdem, Arzum; Muti, Mihrican; Karadeniz, Hakan; Congur, Gulsah; Canavar, Ece

    2012-06-15

    Single walled carbon nanotubes (SWCNT)-chitosan (CHIT) modified pencil graphite electrodes (PGEs) were developed for monitoring of DNA hybridization. SWCNT-chitosan modified PGE (CNT-CHIT-PGE), Chitosan modified PGE (CHIT-PGE) and unmodified PGE (bare-PGE) were firstly characterized by using scanning electron microscopy (SEM), and their electrochemical behaviors were investigated using electrochemical impedance spectroscopy (EIS). The concentrations of CHIT, carbon nanotube (CNT) and also amino linked DNA probe etc. were respectively optimized in order to obtain the better working conditions of CNT-CHIT modified PGE in DNA analysis. The sequence selective DNA hybridization related to Hepatitis B virus (HBV) was then explored in the case of hybridization between amino linked HBV probe and its complementary (target), or noncomplementary (NC), or mismatch (MM) sequences, and also hybridization in mixture sample. PMID:22459926

  12. Design, characterization and in vitro evaluation of 5-aminosalicylic acid loaded N-succinyl-chitosan microparticles for colon specific delivery.

    PubMed

    Mura, C; Nácher, A; Merino, V; Merino-Sanjuán, M; Manconi, M; Loy, G; Fadda, A M; Díez-Sales, O

    2012-06-01

    The objective of this study was to prepare NS-chitosan microparticles for the delivery of 5-aminosalicylic acid (5-ASA) to the colon. Microparticles can spread out over a large area of colon allowing a more effective local efficacy of 5-ASA. N-Succinyl-chitosan was chosen as carrier system because of its excellent pharmaceutical properties in colon drug targeting such as poor solubility in acid environment, biocompatibility, mucoadhesive properties, and low toxicity. It was prepared by introducing succinic group into chitosan N-terminals of the glucosamine units. 5-ASA loaded NS-chitosan microparticles were prepared using spray-drying. As a control, a matrix obtained by freeze-drying technique was also prepared and tested. Fourier transform infrared (FT-IR), differential scanning calorimetry (DSC) and X-ray diffraction studies show the 5-ASA/NS-chitosan electrostatic interactions in both the systems. Mean size of the microparticles was around 5 ?m, zeta potential value of both systems was always negative. Scanning electron microscopy (SEM) images show an acceptable spherical non porous structure of microparticles. In vitro swelling and drug release studies were in accordance with the polymer properties, showing the highest swelling ratio and drug release at pH=7.4 (colonic pH) where microparticles were able to deliver more than 90% of 5-ASA during 24h experiments. Rheological studies are in accordance with the swelling and release studies. PMID:22341520

  13. In vitro treatments of Echinococcus granulosus with fungal chitosan, as a novel biomolecule

    PubMed Central

    Rahimi-Esboei, Bahman; Fakhar, Mahdi; Chabra, Aroona; Hosseini, Mahboobeh

    2013-01-01

    Objective To determined the antiparasitic activity of the isolated chitosan from Penicillium viridicatum, Penicillium aurantiogriseum and commercial chitosan against protoscolicidal of hydatid cysts were determined. Methods After isolating chitosan from fungal cell walls, four concentrations (50, 100, 200, 400 µg/mL) of each type of prepared chitosan and commercial chitosan were used for 10, 30, 60, and 180 min, respectively. Results Among different type of chitosan, commercial chitosan with the highest degree of deacetylation showed high scolicidal activity in vitro. Fungal chitosan could be recommended, as good as commercial chitosan, for hydatic cysts control. Conclusions It seems to be a good alternative to synthetic and chemical scolicidal. PMID:24075347

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

    PubMed Central

    Jia, Sen; Yang, Xinjie; Song, Wen; Wang, Lei; Fang, Kaixiu; Hu, Zhiqiang; Yang, Zihui; Shan, Chun; Lei, Delin; Lu, Bin

    2014-01-01

    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 angiogenic siRNAs may be used as a scaffold for bone regeneration. The dual siRNA concept may also be useful in the biofunctionalization of other materials. PMID:25429217

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

    Microsoft Academic Search

    Zhijiang Cai; Hyoung-Joon Jin; Jaehwan Kim

    2009-01-01

    Bacterial cellulose and chitosan blends have been successfully prepared by immersing wet bacterial cellulose pellicle in chitosan solution followed by freeze-drying. By changing chitosan concentration and immersion time, the chitosan content in the blends is ranged from 12% to 45%. The products look like a foam structure. SEM images show that chitosan molecules can penetrate into bacterial cellulose forming multilayer

  16. Chitosan inhibits premature browning in ground beef.

    PubMed

    Suman, S P; Mancini, R A; Joseph, P; Ramanathan, R; Konda, M K R; Dady, G; Yin, S

    2011-07-01

    Our objective was to evaluate the effect of chitosan on premature browning in refrigerated ground beef patties stored in different packaging systems. Ground beef patties (15% fat) with chitosan (1% w/w) or without chitosan (control) were individually packaged either in vacuum (VP), aerobic packaging (AP), carbon monoxide modified atmosphere packaging (LO-OX; 0.4% CO+19.6% CO(2)+80% N(2)), or high-oxygen modified atmosphere packaging (HI-OX; 80% O(2)+20% CO(2)), and stored for 0, 1, or 3 days at 1°C. At the conclusion of storage, raw surface redness was evaluated, patties were cooked to internal end-point temperatures of either 66°C or 71°C, and internal cooked color was measured. The incorporation of chitosan increased (P<0.05) the interior redness of patties stored in AP, VP, and LO-OX, but not in HI-OX. The results of the present study suggest that the incorporation of 1% chitosan minimizes premature browning in ground beef patties stored under AP, VP, and LO-OX. PMID:21396786

  17. Chitosan-silica hybrid porous membranes.

    PubMed

    Pandis, Christos; Madeira, Sara; Matos, Joana; Kyritsis, Apostolos; Mano, João F; Ribelles, José Luis Gómez

    2014-09-01

    Chitosan-silica porous hybrids were prepared by a novel strategy in order to improve the mechanical properties of chitosan (CHT) in the hydrogel state. The inorganic silica phase was introduced by sol-gel reactions in acidic medium inside the pores of already prepared porous scaffolds. In order to make the scaffolds insoluble in acidic media chitosan was cross-linked by genipin (GEN) with an optimum GEN concentration of 3.2 wt.%. Sol-gel reactions took place with Tetraethylorthosilicate (TEOS) and 3-glycidoxypropyltrimethoxysilane (GPTMS) acting as silica precursors. GPTMS served also as a coupling agent between the free amino groups of chitosan and the silica network. The morphology study of the composite revealed that the silica phase appears as a layer covering the chitosan membrane pore walls. The mechanical properties of the hybrids were characterized by means of compressive stress-strain measurements. By immersion in water the hybrids exhibit an increase in elastic modulus up to two orders of magnitude. PMID:25063153

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

    NASA Astrophysics Data System (ADS)

    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-? in NAFLD were significantly ameliorated by treatment with sulfate chitosan derivatives. Sulfate chitosan derivatives have good pre-treatment and therapeutic effect on NAFLD.

  19. Chitosan in mucoadhesive drug delivery: focus on local vaginal therapy.

    PubMed

    Andersen, Toril; Bleher, Stefan; Eide Flaten, Gøril; Tho, Ingunn; Mattsson, Sofia; Škalko-Basnet, Nataša

    2015-01-01

    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. PMID:25574737

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

    PubMed Central

    Andersen, Toril; Bleher, Stefan; Flaten, Gøril Eide; Tho, Ingunn; Mattsson, Sofia; Škalko-Basnet, Nataša

    2015-01-01

    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. PMID:25574737

  1. Strong adhesion and cohesion of chitosan in aqueous solutions

    PubMed Central

    Lee, Dong Woog; Lim, Chanoong; Israelachvili, Jacob N.; Hwang, Dong Soo

    2014-01-01

    Chitosan, a load-bearing biomacromolecule found in the exoskeletons of crustaceans and insects, is a promising biopolymer for the replacement of synthetic plastic compounds. Here, surface interactions mediated by chitosan in aqueous solutions, including the effects of pH and contact time, were investigated using a surface forces apparatus (SFA). Chitosan films showed an adhesion to mica for all tested pH ranges (3.0–8.5), achieving a maximum value at pH 3.0 after a contact time of 1 hr (Wad ~6.4 mJ/m2). We also found weak or no cohesion between two opposing chitosan layers on mica in aqueous buffer until the critical contact time for maximum adhesion (chitosan-mica) was reached. Strong cohesion (Wco ~8.5 mJ/m2) between the films was measured with increasing contact times up to 1 hr at pH 3.0, which is equivalent to ~60% of the strongest, previously reported, mussel underwater adhesion. Such time-dependent adhesion properties are most likely related to molecular or molecular group reorientations and interdigitations. At high pH (8.5), the solubility of chitosan changes drastically, causing the chitosan-chitosan (cohesion) interaction to be repulsive at all separation distances and contact times. The strong contact time and pH-dependent chitosan-chitosan cohesion and adhesion properties provide new insight into the development of chitosan based load-bearing materials. PMID:24138057

  2. Using nano-chitosan for harvesting microalga Nannochloropsis sp.

    PubMed

    Farid, Mohammad Sadegh; Shariati, Ahmad; Badakhshan, Amir; Anvaripour, Bagher

    2013-03-01

    In this study, chitosan and nano-chitosan were used as flocculants agents for harvesting microalga Nannochloropsis sp. chitosan was modified to nano-chitosan by crosslinking with sodium tripolyphosphate. The effects of type and dosage of flocculants and the pH of the culture were investigated on biomass recovery. Optimum dosages for both bio-flocculants were found. The results showed that the dosage of flocculant consumption decreases by 40% and biomass recovery increases by 9% when nano-chitosan instead of chitosan is used as flocculant agent. Also, the recycled water from the harvesting process was reused which increases the growth of microalgae by about 7%. Finally, the cost analysis of harvesting process showed the feasibility of using nano-chitosan as flocculation agent. PMID:23415940

  3. Zwitterionic chitosan derivatives for pH-sensitive stealth coating.

    PubMed

    Xu, Peisheng; Bajaj, Gaurav; Shugg, Tyler; Van Alstine, William G; Yeo, Yoon

    2010-09-13

    Zwitterionic chitosan, a chitosan derivative with a unique pH-dependent charge profile, was employed to create a stealth coating on the cationic surface of drug carriers. Zwitterionic chitosans were synthesized by amidation of chitosan with succinic anhydride. The succinic anhydride-conjugated chitosan had an isoelectric point, which could be easily tuned from pH 4.9 to 7.1 and showed opposite charges below and above the isoelectric point. The succinic anhydride-conjugated chitosan was able to inhibit the protein adsorption to the cationic surface at physiological pH, compatible with blood components and well tolerated upon intraperitoneal injection. The succinic anhydride-conjugated chitosan has the potential to serve as a coating material to prevent protein adsorption to cationic surfaces, which can be removed in a pH-responsive manner. PMID:20695636

  4. Surface structure of chitosan and hybrid chitosan-amylose films-restoration of the antibacterial properties of chitosan in the amylose film.

    PubMed

    Suzuki, Shiho; Ying, Bo; Yamane, Hideki; Tachi, Hideki; Shimahashi, Katsumasa; Ogawa, Kozo; Kitamura, Shinichi

    2007-11-26

    The surface structure of films prepared by casting aqueous solutions of mixtures of water soluble chitosan (WSC) and amylose as well as a fully deacetylated chitosan was studied. Zeta potential measurements indicated that the surface of WSC and fully deacetylated chitosan films is positively charged but very weakly, whereas, a film of amylose blended with WSC exhibited an obvious positive charge. X-ray photoelectron spectra of these films suggest that less amino groups are exposed on the surface of WSC and fully deacetylated chitosan films, whereas, more amino groups are exposed on the surface of a WSC film blended with amylose. A sheet structure in which free amino groups are less exposed on the surface of the film of WSC or fully deacetylated chitosan is proposed. This accounts for the loss of antibacterial activity of chitosan on the WSC film surface. When blended with amylose, the morphology of the film may be disrupted, resulting in strong antibacterial properties. PMID:17669384

  5. Formulation and comparative characterization of chitosan, gelatin, and chitosan-gelatin-coated liposomes of CPT-11-HCl.

    PubMed

    Shende, Pravin; Gaud, Ram

    2009-05-01

    Liposomes containing phosphatidylcholine and cholesterol (uncoated) and coated by chitosan, gelatin, and combination of chitosan and gelatin were prepared by the modified ethanol injection method. The aim of this work was to formulate and characterize liposomes of camptothecin (CPT)-11-HCl (Irinotecan HCl) containing chitosan, gelatin, and both polymers as coating materials; and also to increase its circulation longevity when compared with the free drug while maintaining the agent in its active lactone form. Size, shape, zeta potential, encapsulation efficiency, stability study, in vitro, and in vivo release study were used for characterization of liposomes. The size of liposomes was in the order of uncoated < chitosan coated < gelatin coated < combination of chitosan and gelatin coated. The zeta potential of liposomes was in the order of combination of chitosan and gelatin coated > chitosan coated > gelatin coated > uncoated. The formulations showed the long-term stability. The encapsulation efficiency of liposomes was in order of combination of chitosan and gelatin coated > gelatin coated > chitosan coated > uncoated. The in vitro and in vivo release of drug was observed in the order of combination chitosan and gelatin coated > gelatin coated > chitosan coated > uncoated. PMID:18951273

  6. Comparison and Characterisation of Regenerated Chitosan from 1-Butyl-3-methylimidazolium Chloride and Chitosan from Crab Shells

    PubMed Central

    Arnold, Lyndon

    2015-01-01

    Chitosan is a biopolymer derived from chitin which is naturally occurring in the exoskeleton of crustaceans. This paper reports dissolution and regeneration of chitosan by directly dissolving in an ionic liquid solvent, 1-butyl-3-methylimidazolium chloride (BMIMCl). This will provide an ideal platform to solubilise these kinds of polymers to achieve the dissolution. The current study dissolved chitosan from crab shell utilising BMIMCl as a solvent and characterised the resultant regenerated polymer. The regenerated chitosan showed increased hydrogen bonding when characterised by Fourier transform infrared (FTIR) spectral analysis. In addition, the study also compared the characteristics of regenerated and generic chitosan. The regenerated chitosan was also evaluated for antimicrobial properties and showed to possess antibacterial features similar to the commercial grade. This method can be utilised in future for blending of polymers with chitosan in a dissolved phase. PMID:26090452

  7. Comparison and Characterisation of Regenerated Chitosan from 1-Butyl-3-methylimidazolium Chloride and Chitosan from Crab Shells.

    PubMed

    Islam, Saniyat; Arnold, Lyndon; Padhye, Rajiv

    2015-01-01

    Chitosan is a biopolymer derived from chitin which is naturally occurring in the exoskeleton of crustaceans. This paper reports dissolution and regeneration of chitosan by directly dissolving in an ionic liquid solvent, 1-butyl-3-methylimidazolium chloride (BMIMCl). This will provide an ideal platform to solubilise these kinds of polymers to achieve the dissolution. The current study dissolved chitosan from crab shell utilising BMIMCl as a solvent and characterised the resultant regenerated polymer. The regenerated chitosan showed increased hydrogen bonding when characterised by Fourier transform infrared (FTIR) spectral analysis. In addition, the study also compared the characteristics of regenerated and generic chitosan. The regenerated chitosan was also evaluated for antimicrobial properties and showed to possess antibacterial features similar to the commercial grade. This method can be utilised in future for blending of polymers with chitosan in a dissolved phase. PMID:26090452

  8. Preparation of a novel chitosan derivative and use in water treatment

    Microsoft Academic Search

    Min Zhang; ChengYu Tan; Liang Kong; LuChen Jin

    2011-01-01

    Chitosan-betaine derivative was prepared by chitosan and betaine hydrochloride through dry process in the presence of dicyandiamide. The product exhibited solubility, practical flocculating property and antibacterial efficacy. Keywords—Chitosan-betaine derivative; Water treatment

  9. Carboxymethyl chitosan represses tumor angiogenesis in vitro and in vivo.

    PubMed

    Jiang, Zhiwen; Han, Baoqin; Li, Hui; Yang, Yan; Liu, Wanshun

    2015-09-20

    Carboxymethyl chitosan (CMCS), with potent water solubility, biocompatibility, and non-toxicity, has emerged as a promising candidate for biomedical applications. In this study, the anti-tumor angiogenesis effects of CMCS were evaluated in vitro and in vivo. Our results showed that CMCS could inhibit the 2-dimensional and 3-dimensional migration of human umbilical vein endothelial cells (HUVECs) in vitro. CMCS significantly inhibited the growth of mouse hepatocarcinoma 22 tissues and could promote tumor cell necrosis as suggested by pathological observations. The CD34 expression in H22 tumor tissue, the levels of vascular endothelial growth factor and tissue inhibitor of metalloproteinase 1 in serum was regulated by CMCS treatment. CMCS could significantly improve thymus index, spleen index, tumor necrosis factor ? and interferon ? level. In a conclusion, CMCS possessed potent anti-tumor effects by inhibiting tumor angiogenesis, stimulating immune functions. Our date provide more foundation for application of CMCS in biomedicine or biomaterials for targeted anticancer drugs delivery. PMID:26050881

  10. Synthesis and structural characterization of chitosan nanogels.

    PubMed

    Brunel, Fabrice; Véron, Laurent; Ladavière, Catherine; David, Laurent; Domard, Alain; Delair, Thierry

    2009-08-18

    Colloidal physical gels of pure chitosan were obtained via an ammonia-induced gelation in a reverse phase emulsion. The water weight fraction and the chitosan concentration in the water phase were optimized so as to yield nanogels with controlled particle size and size distribution. The spherical morphology of the nanogels was established by transmission electron microscopy with negative staining. Wide-angle X-ray scattering experiments showed that these gels were partially crystalline. The electrophoretic mobilities of the particles remained positive up to pH 7, above which the particles aggregated due to the charge neutralization. From the investigation on the colloidal stability of these nanogels in various conditions (pH, salt concentration, temperature), an electrosteric stabilization process of the particles was pointed out, related to the conformation of mobile chitosan chains at the gel-liquid interface. Therefore, the structure of the nanogels was deduced as being core-shell type, a gelified core of neutralized chitosan chains surrounded by partially protonated chains. PMID:19572536

  11. Chitosan Adhesive Films for Photochemical Tissue Bonding

    NASA Astrophysics Data System (ADS)

    Lauto, Antonio; Mawad, Damia; Barton, Matthew; Piller, Sabine C.; Longo, Leonardo

    2011-08-01

    Photochemical tissue bonding (PTB) is a promising sutureless technique for tissue repair. PTB is often achieved by applying a solution of rose bengal (RB) between two tissue edges, which are irradiated by a green laser to crosslink collagen fibers with minimal heat production. In this study, RB has been incorporated in chitosan films to create a novel tissue adhesive that is laser-activated. Materials and Methods. Adhesive films, based on chitosan and containing ˜0.1wt% RB were manufactured and bonded to calf intestine by a solid state laser (wavelength = 532 nm, Fluence ˜110 J/cm2, spot size ˜5 mm). A single-column tensiometer, interfaced with a personal computer, tested the bonding strength. K-type thermocouples recorded the temperature (T) at the adhesive-tissue interface during laser irradiation. Human fibroblasts were also seeded on the adhesive and cultured for 48 hours to assess cell growth. Results and Conclusion. The RB-chitosan adhesive bonded firmly to the intestine (15±2 kPa, n = 31). The adhesion strength dropped to 0.5±0.1 kPa (n = 8) when the laser was not applied to the adhesive. The average temperature of the adhesive increased from 26 °C to 32 °C during laser exposure. Fibroblasts grew confluent on the adhesive without morphological changes. A new biocompatible chitosan adhesive has been developed that bonds photochemically to tissue with minimal temperature increase.

  12. Chitosan-based nanocarriers for antimalarials

    NASA Astrophysics Data System (ADS)

    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.

  13. Chitosan-based scaffolds for bone tissue engineering

    PubMed Central

    Levengood, Sheeny Lan; Zhang, Miqin

    2014-01-01

    Bone defects requiring grafts to promote healing are frequently occurring and costly problems in health care. Chitosan, a biodegradable, naturally occurring polymer, has drawn considerable attention in recent years as scaffolding material in tissue engineering and regenerative medicine. Chitosan is especially attractive as a bone scaffold material because it supports the attachment and proliferation of osteoblast cells as well as formation of mineralized bone matrix. In this review, we discuss the fundamentals of bone tissue engineering and the unique properties of chitosan as a scaffolding material to treat bone defects for hard tissue regeneration. We present the common methods for fabrication and characterization of chitosan scaffolds, and discuss the influence of material preparation and addition of polymeric or ceramic components or biomolecules on chitosan scaffold properties such as mechanical strength, structural integrity, and functional bone regeneration. Finally, we highlight recent advances in development of chitosan-based scaffolds with enhanced bone regeneration capability. PMID:24999429

  14. Glycerophosphate-based chitosan thermosensitive hydrogels and their biomedical applications.

    PubMed

    Zhou, Hui Yun; Jiang, Ling Juan; Cao, Pei Pei; Li, Jun Bo; Chen, Xi Guang

    2015-03-01

    Chitosan is non-toxic, biocompatible and biodegradable polysaccharide composed of glucosamine and derived by deacetylation of chitin. Chitosan thermosensitive hydrogel has been developed to form a gel in situ, precluding the need for surgical implantation. In this review, the recent advances in chitosan thermosensitive hydrogels based on different glycerophosphate are summarized. The hydrogel is prepared with chitosan and ?-glycerophosphate or ??-glycerophosphate which is liquid at room temperature and transits into gel as temperature increases. The gelation mechanism may involve multiple interactions between chitosan, glycerophosphate, and water. The solution behavior, rheological and physicochemical properties, and gelation process of the hydrogel are affected not only by the molecule weight, deacetylation degree, and concentration of chitosan, but also by the kind and concentration of glycerophosphate. The properties and the three-dimensional networks of the hydrogel offer them wide applications in biomedical field including local drug delivery and tissue engineering. PMID:25498667

  15. Activity of Chitosans in combination with antibiotics in Pseudomonas aeruginosa

    PubMed Central

    Tin, San; Sakharkar, Kishore R.; Lim, Chu Sing; Sakharkar, Meena K.

    2009-01-01

    Chitosan and its derivative water soluble Chitosan oligosaccharide are used in a variety of applications in pharmaceutical preparations. In this study, 2 wild (ATCC 15729 and PAO1) and 2 mutant strains (PT121 and PT149) of P. aeruginosa are investigated for drug-drug interactions in vitro. 10 antimicrobial agents (antibiotics) are combined with different degree of deacetylated Chitosans and Chitosan oligosaccharide. All the chitosans show synergistic activity with sulfamethoxazole, a sulfonamide antimicrobial agent. It is interesting to observe that the MIC value for the MexEF-OprN overexpressing mutant strain of P. aeruginosa is 5 fold higher than the other strains under investigation suggesting a possible role of this efflux pump in Sulfamethoxazole efflux. The findings suggest on the use of chitosans as enhancing agent in combination with antibiotics in pharmaceutical preparations. PMID:19173037

  16. Activity of Chitosans in combination with antibiotics in Pseudomonas aeruginosa.

    PubMed

    Tin, San; Sakharkar, Kishore R; Lim, Chu Sing; Sakharkar, Meena K

    2009-01-01

    Chitosan and its derivative water soluble Chitosan oligosaccharide are used in a variety of applications in pharmaceutical preparations. In this study, 2 wild (ATCC 15729 and PAO1) and 2 mutant strains (PT121 and PT149) of P. aeruginosa are investigated for drug-drug interactions in vitro. 10 antimicrobial agents (antibiotics) are combined with different degree of deacetylated Chitosans and Chitosan oligosaccharide. All the chitosans show synergistic activity with sulfamethoxazole, a sulfonamide antimicrobial agent. It is interesting to observe that the MIC value for the MexEF-OprN overexpressing mutant strain of P. aeruginosa is 5 fold higher than the other strains under investigation suggesting a possible role of this efflux pump in Sulfamethoxazole efflux. The findings suggest on the use of chitosans as enhancing agent in combination with antibiotics in pharmaceutical preparations. PMID:19173037

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

    PubMed Central

    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

  18. Utilization of chitosan for preservation of raw shrimp (Pandalus borealis)

    Microsoft Academic Search

    B. K. Simpson; N. Gagné; I. N. A. Ashie; E. Noroozi

    1997-01-01

    Whole and headless shrimp (Pandalus borealis) were dipped in various concentrations of chitosan solution and stored for 20 days at 4–7°C. The effects of chitosan on microbial proliferation, total volatile bases, nucleotide breakdown, and blackspot formation were monitored over this period. Chitosan showed strong antimicrobial properties inhibiting several microorganisms at concentrations ranging between 0.0075 ? 0.01%. The Pseudomonads, however, were

  19. Chitosan\\/modified montmorillonite beads and adsorption Reactive Red 120

    Microsoft Academic Search

    Siriwan Kittinaovarat; Panida Kansomwan; Nantana Jiratumnukul

    2010-01-01

    Different molar mass (Mw?) chitosans were prepared by the hydrolysis of commercial Mw? 480,000 chitosan (CTS480) with hydrogen peroxide at 4% (v\\/v) for 6 and 24h and at 15% (v\\/v) for 24h, yielding new smaller polymers of Mw? 130,000 (CTS130), 69,000 (CTS69) and 14,000 (CTS14), respectively. The four chitosan preparations were used to modify montmorillonite (MMT), but all only slightly

  20. Remediation of coal mining wastewaters using chitosan microspheres

    Microsoft Academic Search

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

    2003-01-01

    This study aimed to evaluate the potential use of chitosan and chitosan\\/poly(vinylalcohol) microspheres incorporating with tetrasulphonated copper (II) phthalocyanine (CTS\\/PVA\\/TCP) in the remediation of coal mining wastewaters. The process was monitored by toxicity tests both before and after adsorption treatments with chitosan and microspheres. Physicochemical parameters, including pH and trace?metal concentration, as well as bioindicators of water pollution were used

  1. Removal of Phthalate Esters from Aqueous Solutions by Chitosan Bead

    Microsoft Academic Search

    CHIH-YU CHEN; YING-CHIEN CHUNG

    2006-01-01

    Removal of phthalate esters (PAEs) by chitosan bead in aqueous solution was studied. The adsorption isotherms of PAEs by chitosan bead were well described by Freundlich isotherm equations. Results of kinetic experiments indicated that diheptyl phthalate (DHpP) had the highest adsorption capacity (1.52 mg\\/g) among six PAEs in our research. PAE adsorption efficiency by chitosan bead was examined in both

  2. Thermal and Rheological Behavior of Collagen. Chitosan blends

    Microsoft Academic Search

    A. A. Salomé Machado; V. C. A. Martins; A. M. G. Plepis

    2002-01-01

    Collagen:chitosan blends in 1:1 ratio were prepared and characterized by Fourier transform infrared spectroscopy, thermal\\u000a (DSC, TG) and rheological studies. Apparently each material maintains its behavior and addition of chitosan does not denature\\u000a collagen fibers. The rheological behavior showed that adding chitosan to collagen causes a decrease of storage modulus (G’),viscous\\u000a loss modulus (G”) and apparent viscosity when measured as

  3. Desulfurization of Gasoline using Molecularly Imprinted Chitosan as Selective Adsorbents

    Microsoft Academic Search

    Yonghui Chang; Lei Zhang; Hanjie Ying; Zhenjiang Li; Hao Lv; Pingkai Ouyang

    2010-01-01

    For desulfurization of gasoline, novel chitosan-based molecularly imprinted polymer (MIP) was prepared by cross-linking chitosan\\u000a with epichlorohydrin in the presence of dibenzothiophene (DBT) as the template. The influence of cross-linking ratio on the\\u000a specific adsorption was evaluated. The effects of the types and the amounts of porogen on selectivity of the chitosan MIP\\u000a were also examined. Results showed that MIP

  4. Dual effects of chitosan decoration on the liposomal membrane physicochemical properties as affected by chitosan concentration and molecular conformation.

    PubMed

    Tan, Chen; Xue, Jin; Eric, Karangwa; Feng, Biao; Zhang, Xiaoming; Xia, Shuqin

    2013-07-17

    This study was devoted to a further understanding of the dependence of liposomal membrane properties on chitosan conformation and proved the dual effects of chitosan. The concentration dependence of chitosan conformation in aqueous solution was illustrated by surface tension and fluorescence probe techniques. Fluorescence and Raman spectra were subsequently employed to investigate the dynamic and structural changes of the liposomal membrane resulting from chitosan decoration. Results showed that the unfolded and crimped chains of chitosan flatly adsorbed onto the membrane surface via electrostatic attraction and favored liposome stability. Furthermore, the adsorption of crimped chains seemed stronger due to the embedding of their hydrophobic moieties. However, the presence of chitosan coils induced the increase in membrane fluidity, the intrachain disorder in lipid molecules, and the gauche conformation change of choline group. Dynamic light scattering and lipid oxidation measurements demonstrated that this perturbation was correlated with the permeation of coils into the lipid bilayer. PMID:23772808

  5. Chitosan intercalated montmorillonite: Preparation, characterization and cationic dye adsorption

    Microsoft Academic Search

    Pathavuth Monvisade; Punnama Siriphannon

    2009-01-01

    Chitosan intercalated montmorillonite (Chi-MMT) was prepared by dispersing sodium montmorillonite (Na+-MMT) into chitosan solution at 60 °C for 24 h. The Chi-MMT was characterized by XRD, XRF and FT-IR. The intercalation was accomplished via the ion-exchange of Na+ ions with –NH3+ of chitosan, resulting in the expansion of d001 from 1.42 nm of Na+-MMT to 2.21 nm of Chi-MMT. The chitosan content in the

  6. Applied usage of yeast spores as chitosan beads.

    PubMed

    Zhang, Haini; Tachikawa, Hiroyuki; Gao, Xiao-Dong; Nakanishi, Hideki

    2014-08-01

    In this study, we present a nonhazardous biological method of producing chitosan beads using the budding yeast Saccharomyces cerevisiae. Yeast cells cultured under conditions of nutritional starvation cease vegetative growth and instead form spores. The spore wall has a multilaminar structure with the chitosan layer as the second outermost layer. Thus, removal of the outermost dityrosine layer by disruption of the DIT1 gene, which is required for dityrosine synthesis, leads to exposure of the chitosan layer at the spore surface. In this way, spores can be made to resemble chitosan beads. Chitosan has adsorptive features and can be used to remove heavy metals and negatively charged molecules from solution. Consistent with this practical application, we find that spores are capable of adsorbing heavy metals such as Cu(2+), Cr(3+), and Cd(2+), and removal of the dityrosine layer further improves the adsorption. Removal of the chitosan layer decreases the adsorption, indicating that chitosan works as an adsorbent in the spores. Besides heavy metals, spores can also adsorb a negatively charged cholesterol derivative, taurocholic acid. Furthermore, chitosan is amenable to chemical modifications, and, consistent with this property, dit1? spores can serve as a carrier for immobilization of enzymes. Given that yeast spores are a natural product, our results demonstrate that they, and especially dit1? mutants, can be used as chitosan beads and used for multiple purposes. PMID:24907339

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

    PubMed

    Koppolu, Bhanu Prasanth; Smith, Sean G; Ravindranathan, Sruthi; Jayanthi, Srinivas; Suresh Kumar, Thallapuranam K; Zaharoff, David A

    2014-05-01

    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 ?m, 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%, were 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

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

    PubMed Central

    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 ?m, 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

  9. Biodegradation and biocompatibility of a degradable chitosan vascular prosthesis

    PubMed Central

    Kong, Xiaoying; Xu, Wenhua

    2015-01-01

    An instrument made by ourselves was used to fabricate biodegradable chitosan-heparin artificial vascular prosthesis with small internal diameter (2 mm) and different crosslinking degree from biodegradable chitosan, chitosan derivates and heparin. In vivo and in vitro degradation studies, inflammatory analysis and electron microscope scanning of this artificial vascular prosthesis were performed. It was observed that 50% of the prosthesis decomposed in vivo and was replaced by natural tissues. The degradation process of the chitosan-heparin artificial vascular prosthesis of small diameter could be controlled by changing the crosslinking degree. This kind of artificial vascular prosthesis shows good biocompatibility that can be controllability designed to achieve desirable in vascular replacement application.

  10. Removal of copper(II) ions from aqueous solution onto chitosan and cross-linked chitosan beads

    Microsoft Academic Search

    W. S Wan Ngah; C. S Endud; R Mayanar

    2002-01-01

    The adsorption of Cu(II) ions onto chitosan and cross-linked chitosan beads has been investigated. Chitosan beads were cross-linked with glutaraldehyde (GLA), epichlorohydrin (ECH) and ethylene glycol diglycidyl ether (EGDE) in order to obtain sorbents that are insoluble in aqueous acidic and basic solution. Batch adsorption experiments were carried out as a function of pH, agitation period, agitation rate and concentration

  11. Ion-imprinted chitosan gel beads for selective adsorption of Ag(+) from aqueous solutions.

    PubMed

    Zhang, Meng; Helleur, Robert; Zhang, Yan

    2015-10-01

    In this study, the Ag(+)-imprinted chitosan gel beads were synthesized to selectively adsorb Ag(+) from bimetallic aqueous solutions containing the same molar concentration of Ag(+) and Cu(2+). The Ag(+)-imprinting not only helps to achieve extremely high selectivity of Ag(+), but also enhances the uptake capacity of the target Ag(+) by protecting some amine groups, the primary binding sites of metal ions from cross-linking. The maximum uptake of Ag(+) by the ion-imprinted chitosan beads was found to be 89.20mgg(-1) at 25.0°C with an initial Ag(+) concentration of 352.95mgL(-1) and the biosorbent dosage of 1.0gL(-1). The adsorption equilibrium and kinetics of Ag(+) by the ion-imprinted chitosan beads can be better described by Langmuir isotherm and the intraparticle diffusion model. FTIR and XPS analyses suggested that amine functional groups involve the binding of Ag(+) via complexation at higher solution pH (3.0?pH?5.0) and ion exchange at lower solution pH (1.0?pH<3.0). PMID:26076618

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

    PubMed

    Ba?ak, 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 ?mol H2O2/min, 197.50 ?mol 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. PMID:23316810

  13. Characterization of fatty acid liposome coated with low-molecular-weight chitosan.

    PubMed

    Tan, Hsiao Wei; Misran, Misni

    2012-12-01

    Preparation of chitosan-coated fatty acid liposomes is often restricted by the solubility of chitosan under basic conditions. In this experiment, the preparation of chitosan-coated oleic acid (OA) liposomes using low molecular weight (LMW) chitosan (10 and 25 kDA) was demonstrated. These selected LMW chitosans are water soluble. The coating of the chitosan layer on OA liposomes was confirmed by its microscope images and physicochemical properties, such as zeta potential and the size of the liposomes. The "peeling off" effect on the surface of chitosan-coated OA liposomes was observed in the atomic force microscope images and showed the occurrence of the chitosan layer on the surface of OA liposomes. The size of the chitosan-coated liposomes was at least 20?nm smaller than the OA liposomes, and the increase of zeta potential with the increasing amount of LMW chitosan further confirmed the presence of the surface modification of OA liposomes. PMID:22881198

  14. Morphology and gelation of thermosensitive chitosan hydrogels.

    PubMed

    Crompton, K E; Prankerd, R J; Paganin, D M; Scott, T F; Horne, M K; Finkelstein, D I; Gross, K A; Forsythe, J S

    2005-08-22

    The morphology of physical hydrogels is often difficult to examine due to the delicate nature of the system and therefore has not been studied in detail. Chitosan/GP (glycerophosphate salt) is a significant hydrogel in the biomedical and cosmetic fields as it is thermosensitive and contains less than 5% polysaccharide. The morphology of this system was examined with laser scanning confocal microscopy (LSCM) to image the gel morphology. The images indicate that the gel is quite heterogeneous, and power spectra reveal a fractal-like morphology. A study of composition found that increasing chitosan concentration increased the amount of polymer-rich phase present in the gel, and that the smallest aggregates decreased in size. PMID:15905019

  15. Chitosan electrodeposition for microrobotic drug delivery.

    PubMed

    Fusco, Stefano; Chatzipirpiridis, George; Sivaraman, Kartik M; Ergeneman, Olgaç; Nelson, Bradley J; Pané, Salvador

    2013-07-01

    A method to functionalize steerable magnetic microdevices through the co-electrodeposition of drug loaded chitosan hydrogels is presented. The characteristics of the polymer matrix have been investigated in terms of fabrication, morphology, drug release and response to different environmental conditions. Modifications of the matrix behavior could be achieved by simple chemical post processing. The system is able to load and deliver 40-80 ?g cm(-2) of a model drug (Brilliant Green) in a sustained manner with different profiles. Chitosan allows a pH responsive behavior with faster and more efficient release under slightly acidic conditions as can be present in tumor or inflamed tissue. A prototype of a microrobot functionalized with the hydrogel is presented and proposed for the treatment of posterior eye diseases. PMID:23355508

  16. Sorption of malachite green on chitosan bead

    Microsoft Academic Search

    Zehra Bekçi; Co?an Özveri; Yolda? Seki; Kadir Yurdakoç

    2008-01-01

    Chitosan bead was synthesized for the removal of a cationic dye malachite green (MG) from aqueous solution. The effects of temperature (303, 313 and 323K), pH of the solution (2–11) on MG removal was investigated. Preliminary kinetic experiment was carried out up to 480min. The sorption equilibrium was reached within 5h (300min). In order to determine the adsorption capacity, the

  17. Food applications of chitin and chitosans

    Microsoft Academic Search

    Fereidoon Shahidi; Janak Kamil Vidana Arachchi; You-Jin Jeon

    1999-01-01

    Chitin is the second most abundant natural biopolymer after cellulose. The chemical structure of chitin is similar to that of cellulose with 2-acetamido-2-deoxy-?-d-glucose (NAG) monomers attached via ?(1?4) linkages. Chitosan is the deacetylated (to varying degrees) form of chitin, which, unlike chitin, is soluble in acidic solutions. Application of chitinous products in foods and pharmaceuticals as well as processing aids

  18. Direct compression properties of chitin and chitosan

    Microsoft Academic Search

    Viviana García Mir; Jyrki Heinämäki; Osmo Antikainen; Ofelia Bilbao Revoredo; Antonio Iraizoz Colarte; Olga Maria Nieto; Jouko Yliruusi

    2008-01-01

    Deformation and compaction properties of native amino poly-saccharides chitin and chitosan were studied and compared with those obtained with established pharmaceutical direct compression excipients. An instrumented single-punch tablet machine was used for tablet compaction. The following compression parameters were evaluated: a ratio of crushing strength and compression pressure, plasticity and elasticity factor (PF and EF), tensile strength and R-value. Chitin

  19. Use of Chitosan to Prolong Mozzarella Cheese Shelf Life

    Microsoft Academic Search

    C. Altieri; C. Scrocco; M. Sinigaglia; M. A. Del Nobile

    2005-01-01

    This study was undertaken to evaluate the feasibility of using chitosan, a natural antimicrobial substance, to improve the preservation of a very perishable cheese. The effectiveness of chitosan to inhibit the growth of spoilage microorganisms in Mozzarella cheese was studied during refrigerated storage. A lactic acid\\/chito- san solution was added directly to the starter used for Mozzarella cheese manufacturing. Mozzarella

  20. Preparation and biomedical applications of chitin and chitosan nanofibers.

    PubMed

    Azuma, Kazuo; Ifuku, Shinsuke; Osaki, Tomohiro; Okamoto, Yoshiharu; Minami, Saburo

    2014-10-01

    Chitin (?-(1-4)-poly-N-acetyl-D-glucosamine) is widely distributed in nature and is the second most abundant polysaccharide after cellulose. Chitin occurs in nature as ordered macrofibrils. It is the major structural component in the exoskeleton of crab and shrimp shells and the cell wall of fungi and yeast. As chitin is not readily dissolved in common solvents, it is often converted to its more deacetylated derivative, chitosan. Chitin, chitosan, and its derivatives are widely used in tissue engineering, wound healing, and as functional foods. Recently, easy methods for the preparation of chitin and chitosan nanofibers have been developed, and studies on biomedical applications of chitin and chitosan nanofibers are ongoing. Chitin and chitosan nanofibers are considered to have great potential for various biomedical applications, because they have several useful properties such as high specific surface area and high porosity. This review summarizes methods for the preparation of chitin and chitosan nanofibers. Further, biomedical applications of chitin and chitosan nanofibers in (i) tissue engineering, (ii) wound dressing, (iii) cosmetic and skin health, (iv) stem cell technology, (v) anti-cancer treatments and drug delivery, (vi) anti-inflammatory treatments, and (vii) obesity treatment are summarized. Many studies indicate that chitin and chitosan nanofibers are suitable materials for various biomedical applications. PMID:25992423

  1. Electrically Conductive Chitosan/Carbon Scaffolds for Cardiac Tissue Engineering

    PubMed Central

    2015-01-01

    In this work, carbon nanofibers were used as doping material to develop a highly conductive chitosan-based composite. Scaffolds based on chitosan only and chitosan/carbon composites were prepared by precipitation. Carbon nanofibers were homogeneously dispersed throughout the chitosan matrix, and the composite scaffold was highly porous with fully interconnected pores. Chitosan/carbon scaffolds had an elastic modulus of 28.1 ± 3.3 KPa, similar to that measured for rat myocardium, and excellent electrical properties, with a conductivity of 0.25 ± 0.09 S/m. The scaffolds were seeded with neonatal rat heart cells and cultured for up to 14 days, without electrical stimulation. After 14 days of culture, the scaffold pores throughout the construct volume were filled with cells. The metabolic activity of cells in chitosan/carbon constructs was significantly higher as compared to cells in chitosan scaffolds. The incorporation of carbon nanofibers also led to increased expression of cardiac-specific genes involved in muscle contraction and electrical coupling. This study demonstrates that the incorporation of carbon nanofibers into porous chitosan scaffolds improved the properties of cardiac tissue constructs, presumably through enhanced transmission of electrical signals between the cells. PMID:24417502

  2. Chitosan Beads as a New Gastroretentive System of Verapamil

    Microsoft Academic Search

    Alaa Eldeen B. Yassin; B. Yassin; Ibrahim A. Alsarra; Abdulah M. Al-Mohize

    2006-01-01

    The main objective of this project is to design a new extended release gastroretentive mutiparticulate delivery system for verapamil (VP) by incorporation into hydrogel beads made of chitosan. The beads were formed by dropping solutions of VP and chitosan in a solution of tripolyphosphate using a syringe pump with adjustable constant rate. The formed beads were then further crosslinked using

  3. Fabrication of chitosan-magnetite nanocomposite strip for chromium removal

    NASA Astrophysics Data System (ADS)

    Sureshkumar, Vaishnavi; Kiruba Daniel, S. C. G.; Ruckmani, K.; Sivakumar, M.

    2015-03-01

    Environmental pollution caused by heavy metals is a serious threat. In the present work, removal of chromium was carried out using chitosan-magnetite nanocomposite strip. Magnetite nanoparticles (Fe3O4) were synthesized using chemical co-precipitation method at 80 °C. The nanoparticles were characterized using UV-visible spectroscopy, fourier transform infrared spectroscopy, X-ray diffraction spectrometer, atomic force microscope, dynamic light scattering and vibrating sample magnetometer, which confirm the size, shape, crystalline nature and magnetic behaviour of nanoparticles. Atomic force microscope revealed that the particle size was 15-30 nm and spherical in shape. The magnetite nanoparticles were mixed with chitosan solution to form hybrid nanocomposite. Chitosan strip was casted with and without nanoparticle. The affinity of hybrid nanocomposite for chromium was studied using K2Cr2O7 (potassium dichromate) solution as the heavy metal solution containing Cr(VI) ions. Adsorption tests were carried out using chitosan strip and hybrid nanocomposite strip at different time intervals. Amount of chromium adsorbed by chitosan strip and chitosan-magnetite nanocomposite strip from aqueous solution was evaluated using UV-visible spectroscopy. The results confirm that the heavy metal removal efficiency of chitosan-magnetite nanocomposite strip is 92.33 %, which is higher when compared to chitosan strip, which is 29.39 %.

  4. Correlation of chitosan's rheological properties and its ability to electrospin.

    PubMed

    Klossner, Rebecca R; Queen, Hailey A; Coughlin, Andrew J; Krause, Wendy E

    2008-10-01

    Chitosan-based, defect-free nanofibers with average diameters ranging from 62 +/- 9 nm to 129 +/- 16 nm were fabricated via electrospinning blended solutions of chitosan and polyethylene oxide (PEO). Several solution parameters such as acetic acid concentration, polymer concentration, and polymer molecular weight were investigated to optimize fiber consistency and diameter. These parameters were evaluated using the rheological properties of the solutions as well as images produced by scanning electron microscopy (SEM) of the electrospun nanofibers. Generally, SEM imaging demonstrated that as total polymer concentration (chitosan + PEO) increased, the number of beads decreased, and as chitosan concentration increased, fiber diameter decreased. Chitosan-PEO solutions phase separate over time; as a result, blended solutions were able to be electrospun with the weakest electric field and the least amount of complications when solutions were electrospun within 24 h of initially being blended. The addition of NaCl stabilized these solutions and increased the time the blended solutions could be stored before electrospinning. Pure chitosan nanofibers with high degrees of deacetylation (about 80%) were unable to be produced. When attempting to electrospin highly deacetylated chitosan from aqueous acetic acid at concentrations above the entanglement concentration, the electric field was insufficient to overcome the combined effect of the surface tension and viscosity of the solution. Therefore, the degree of deacetylation is an extremely important parameter to consider when attempting to electrospin chitosan. PMID:18785774

  5. Chitosan sponges as tissue engineering scaffolds for bone formation

    Microsoft Academic Search

    Yang-Jo Seol; Jue-Yeon Lee; Yoon-Jeong Park; Yong-Moo Lee; Young-Ku; In-Chul Rhyu; Seung-Jin Lee; Soo-Boo Han; Chong-Pyoung Chung

    2004-01-01

    Rat calvarial osteoblasts were grown in porous chitosan sponges fabricated by freeze drying. The prepared chitosan sponges had a porous structure with a 100–200 µm pore diameter, which allowed cell proliferation. Cell density, alkaline phosphatase activity and calcium deposition were monitored for up to 56 d culture. Cell numbers were 4 × 106 (day 1), 11 × 106 (day 28) and 12 ×

  6. Some biomedical applications of chitosan-based hybrid nanomaterials

    Microsoft Academic Search

    Dai Lam Tran; Gia Dien Pham; Xuan Phuc Nguyen; Dinh Hoang Vu; Ngoc Thinh Nguyen; Vinh Hoang Tran; Thi Thu Trang Mai; Hai Binh Nguyen; Quang Duong Le; Thi Ngoan Nguyen; Thi Cham Ba

    2011-01-01

    Being naturally abundant resources and having many interesting physicochemical and biological properties, chitin\\/chitosan have been found to be useful in many fields, especially biomedical ones. This paper describes the strategy to design multifunctional, hybrid chitosan-based nanomaterials and test them in some typical biomedical applications.

  7. Novel thermosensitive chitosan hydrogels: in vivo evaluation.

    PubMed

    Patois, Emilie; Osorio-da Cruz, Suzanne; Tille, Jean-Christophe; Walpoth, Beat; Gurny, Robert; Jordan, Olivier

    2009-11-01

    Chitosan is an attractive biopolymer for the preparation of hydrogels. Its unique combination of biocompatibility, biodegradability, bioadhesivity, and tissue-promoting abilities allows pharmaceutical applications. We investigated novel thermosensitive hydrogels based on chitosan homogeneously reacetylated to a deacetylation degree of about 50%, combined with selected polyols or polyoses such as trehalose, a nontoxic polysaccharide. The latter, a gel-inducing and lyoprotective agent enabled the formulation to be lyophilized and rehydrated without affecting the thermosensitive behavior. This made possible long-term storage and promoted its use in a clinical setup. The thermally induced sol-gel transition allowed injectability and in situ setting. Rheological characterization revealed that storage moduli could be increased by one decade by increasing the chitosan concentration from 1.4 to 2.2% (w/w). Evaluation in vivo provided evidence of in situ implant formation in subcutaneous tissue of Sprague-Dawley rats and permanence for up to 3 months. Histopathological analysis demonstrated a mild, chronic, inflammatory reaction that disappeared with the complete absorption of the gel implant over a few months period. Such in situ forming hydrogels could be advantageous for specific applications in drug delivery and tissue engineering. PMID:18980189

  8. Chitosan films and blends for packaging material.

    PubMed

    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. PMID:25458295

  9. Carbon nanotube–chitosan modified disposable pencil graphite electrode for Vitamin B 12 analysis

    Microsoft Academic Search

    Filiz Kuralay; Tayfun Vural; Cem Bayram; Emir Baki Denkbas; Serdar Abaci

    2011-01-01

    A single walled carbon nanotube–chitosan (SWCNT–chitosan) modified disposable pencil graphite electrode (PGE) was used in this study for the electrochemical detection of Vitamin B12. Electrochemical behaviors of SWCNT–chitosan PGE and chitosan modified PGE were compared by using cyclic voltammetry (CV), square-wave voltammetry (SWV) and electrochemical impedance spectroscopy (EIS) techniques. SWCNT–chitosan modified electrode was also used for the quantification of Vitamin

  10. Dairy Wastewater Treatment Using Low Molecular Weight Crab Shell Chitosan

    NASA Astrophysics Data System (ADS)

    Geetha Devi, M.; Dumaran, Joefel Jessica; Feroz, S.

    2012-08-01

    The investigation of possible use of low molecular weight crab shell chitosan (MW 20 kDa) in the treatment of dairy waste water was studied. Various experiments have been carried out using batch adsorption technique to study the effects of the process variables, which include contact time, stirring speed, pH and adsorbent dosage. Treated effluent characteristics at optimum condition showed that chitosan can be effectively used as adsorbent in the treatment of dairy wastewater. The optimum conditions for this study were at 150 mg/l of chitosan, pH 5 and 50 min of mixing time with 50 rpm of mixing speed. Chitosan showed the highest performance under these conditions with 79 % COD, 93 % turbidity and 73 % TSS reduction. The result showed that chitosan is an effective coagulant, which can reduce the level of COD, TSS and turbidity in dairy industry wastewater.

  11. Physiochemical and optical properties of chitosan based graphene oxide bionanocomposite.

    PubMed

    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. PMID:25077836

  12. Antimicrobial coating of modified chitosan onto cotton fabrics

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

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

  13. Chitosan-based hydrogels for controlled, localized drug delivery.

    PubMed

    Bhattarai, Narayan; Gunn, Jonathan; Zhang, Miqin

    2010-01-31

    Hydrogels are high-water content materials prepared from cross-linked polymers that are able to provide sustained, local delivery of a variety of therapeutic agents. Use of the natural polymer, chitosan, as the scaffold material in hydrogels has been highly pursued thanks to the polymer's biocompatibility, low toxicity, and biodegradability. The advanced development of chitosan hydrogels has led to new drug delivery systems that release their payloads under varying environmental stimuli. In addition, thermosensitive hydrogel variants have been developed to form a chitosan hydrogel in situ, precluding the need for surgical implantation. The development of these intelligent drug delivery devices requires a foundation in the chemical and physical characteristics of chitosan-based hydrogels, as well as the therapeutics to be delivered. In this review, we investigate the newest developments in chitosan hydrogel preparation and define the design parameters in the development of physically and chemically cross-linked hydrogels. PMID:19799949

  14. Proteomic profiling of Stemona alkaloids production response to chitosan elicitor.

    PubMed

    Dheeranupattana, S; Sangthong, P; Roytrakul, S; Chaichana, N

    2013-09-15

    The study purposed to investigate the protein expression of Stemona alkaloids biosynthesis response to chitosan elicitor by 2D gel electrophoresis. The total proteins extraction of Stemona roots were performed for comparison with the control and chitosan treatments. It was found that 15 out of 150 protein spots exhibited different expression between control and chitosan culture treatment. The identified 15 protein spots were subjected to amino acid sequencing and two proteins appeared interesting for examining Stemona alkaloids biosynthesis. After treated with chitosan, glutathione S-transferase became down-regulated while heat shock protein up-regulated in relation to the control treatment. These proteins may play roles in alkaloids biosynthesis via plant defense metabolism from the presumptions that chitosan might weaken the detoxifying function of glutathione S-transferase, then, heat shock protein is probably produced to signal for tissue protection mechanism. Thus, Stemona alkaloids may be responsive to this stress. PMID:24502153

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

    PubMed Central

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

    2012-01-01

    Background Schistosomiasis is one of the most important neglected tropical diseases and an effective control is unlikely in the absence of improved sanitation and vaccination. A new approach of oral vaccination with alginate coated chitosan nanoparticles appears interesting because their great stability and the ease of target accessibility, besides of chitosan and alginate immunostimulatory properties. Here we propose a candidate vaccine based on the combination of chitosan-based 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. PMID:23209848

  16. Spectrum and Mechanisms of Inflammasome Activation by Chitosan

    PubMed Central

    Bueter, Chelsea L.; Lee, Chrono K.; Wang, Jennifer P.; Ostroff, Gary R.; Specht, Charles A.; Levitz, Stuart M.

    2014-01-01

    Chitosan, the deacetylated derivative of chitin, can be found in the cell wall of some fungi and is utilized in translational applications. We have shown that highly purified preparations of chitosan, but not chitin, activate the NLRP3 inflammasome in primed mouse bone marrow-derived macrophages (BMM?), inducing a robust IL-1? response. Here, we further define specific cell types that are activated and delineate mechanisms of activation. BMM? differentiated to promote a classically activated (M1) phenotype released more IL-1? in response to chitosan than intermediate or alternatively activated macrophages (M2). Chitosan but not chitin induced a robust IL-1? response in mouse DCs, peritoneal macrophages, and human PBMCs. Three mechanisms for NLRP3 inflammasome activation may contribute: K+ efflux, reactive oxygen species (ROS), and lysosomal destabilization. The contributions of these mechanisms were tested using a K+ efflux inhibitor, high extracellular potassium, a mitochondrial ROS inhibitor, lysosomal acidification inhibitors, and a cathepsin B inhibitor. These studies revealed that each of these pathways participated in optimal NLRP3 inflammasome activation by chitosan. Finally, neither chitosan nor chitin stimulated significant release from unprimed BMM? of any of 22 cytokines and chemokines assayed. In conclusion, 1) chitosan, but not chitin, stimulates IL-1? release from multiple murine and human cell types; 2) multiple non-redundant mechanisms appear to participate in inflammasome activation by chitosan; and 3) chitin and chitosan are relatively weak stimulators of inflammatory mediators from unprimed BMM?. These data have implications for understanding the nature of the immune response to microbes and biomaterials that contain chitin and chitosan. PMID:24829412

  17. Comparison of the effect of different chitosan salts and N-trimethyl chitosan chloride on the permeability of intestinal epithelial cells (Caco-2)

    Microsoft Academic Search

    Awie F Kotzé; Henrik L Lueßen; Bas J de Leeuw; J Coos Verhoef; Hans E Junginger

    1998-01-01

    A partially quaternized chitosan derivative, N-trimethyl chitosan chloride (TMC) (degree of quaternization 12.28%), was synthesized and the effects of this novel polymer on the permeability of intestinal epithelial cells, using Caco-2 cell monolayers, were investigated and compared with those of chitosan hydrochloride and chitosan glutamate. Transepithelial electrical resistance (TEER) measurements at pH 6.20 revealed that all these polymers (0.25–1.5% w\\/v)

  18. Comparative studies on polyelectrolyte complexes and mixtures of chitosan–alginate and chitosan–carrageenan as prolonged diltiazem clorhydrate release systems

    Microsoft Academic Search

    Cristián Tapia; Zunilda Escobar; Edda Costa; Jaime Sapag-Hagar; Fernando Valenzuela; Carlos Basualto; Mar??a Nella Gai; Mehrdad Yazdani-Pedram

    2004-01-01

    The aim of this work was to evaluate the possibility of using mixtures and\\/or polyelectrolyte complexes from both chitosan-alginate and chitosan–carrageenan as prolonged drug release systems. Different dissolution profiles were obtained by changing the polymer matrix system (chitosan–alginate or chitosan–carrageenan) and the method used to include these polymers into the formulation (physical mixture or polyelectrolyte complex). Drug dissolution profiles from

  19. Chitin, Chitosan, and Its Derivatives for Wound Healing: Old and New Materials

    PubMed Central

    Azuma, Kazuo; Izumi, Ryotaro; Osaki, Tomohiro; Ifuku, Shinsuke; Morimoto, Minoru; Saimoto, Hiroyuki; Minami, Saburo; Okamoto, Yoshiharu

    2015-01-01

    Chitin (?-(1-4)-poly-N-acetyl-d-glucosamine) is widely distributed in nature and is the second most abundant polysaccharide after cellulose. It is often converted to its more deacetylated derivative, chitosan. Previously, many reports have indicated the accelerating effects of chitin, chitosan, and its derivatives on wound healing. More recently, chemically modified or nano-fibrous chitin and chitosan have been developed, and their effects on wound healing have been evaluated. In this review, the studies on the wound-healing effects of chitin, chitosan, and its derivatives are summarized. Moreover, the development of adhesive-based chitin and chitosan are also described. The evidence indicates that chitin, chitosan, and its derivatives are beneficial for the wound healing process. More recently, it is also indicate that some nano-based materials from chitin and chitosan are beneficial than chitin and chitosan for wound healing. Clinical applications of nano-based chitin and chitosan are also expected. PMID:25780874

  20. Chitin, chitosan, and its derivatives for wound healing: old and new materials.

    PubMed

    Azuma, Kazuo; Izumi, Ryotaro; Osaki, Tomohiro; Ifuku, Shinsuke; Morimoto, Minoru; Saimoto, Hiroyuki; Minami, Saburo; Okamoto, Yoshiharu

    2015-01-01

    Chitin (?-(1-4)-poly-N-acetyl-D-glucosamine) is widely distributed in nature and is the second most abundant polysaccharide after cellulose. It is often converted to its more deacetylated derivative, chitosan. Previously, many reports have indicated the accelerating effects of chitin, chitosan, and its derivatives on wound healing. More recently, chemically modified or nano-fibrous chitin and chitosan have been developed, and their effects on wound healing have been evaluated. In this review, the studies on the wound-healing effects of chitin, chitosan, and its derivatives are summarized. Moreover, the development of adhesive-based chitin and chitosan are also described. The evidence indicates that chitin, chitosan, and its derivatives are beneficial for the wound healing process. More recently, it is also indicate that some nano-based materials from chitin and chitosan are beneficial than chitin and chitosan for wound healing. Clinical applications of nano-based chitin and chitosan are also expected. PMID:25780874

  1. Oxaliplatin-chitosan nanoparticles induced intrinsic apoptotic signaling pathway: a "smart" drug delivery system to breast cancer cell therapy.

    PubMed

    Vivek, Raju; Thangam, Ramar; Nipunbabu, Varukattu; Ponraj, Thondhi; Kannan, Soundarapandian

    2014-04-01

    This study was to investigate "smart" pH-responsive drug delivery system (DDS) based on chitosan nano-carrier for its potential intelligent controlled release and enhancing chemotherapeutic efficiency of Oxalipaltin. Oxaliplatin was loaded onto chitosan by forming complexes with degradable to construct nano-carrier as a DDS. Oxaliplatin was released from the DDS much more rapidly at pH 4.5 than at pH 7.4, which is a desirable characteristic for tumor-targeted drug delivery. Furthermore, the possible intrinsic apoptotic signaling pathway was explored by Western blot. It was found that expression of Bax, Bik, cytochrome C, caspase-9 and -3 was significantly up-regulated while the Bcl-2 and Survivin were inhibited in breast cancer MCF-7 cells. For instance, nanoparticles inducing apoptosis in caspase-dependent manner indicate that chitosan nanoparticles could act as an efficient DDS importing Oxalipaltin to target cancer cells. These approaches suggest that "smart" Oxaliplatin delivery strategy is a promising approach to cancer therapy. PMID:24472507

  2. Chitosan-based nanofibrous membranes for antibacterial filter applications.

    PubMed

    Cooper, Ashleigh; Oldinski, Rachael; Ma, Hongyan; Bryers, James D; Zhang, Miqin

    2013-01-30

    Nanofibrous membranes have drawn considerable interest for filtration applications due to their ability to withstand high fluid flux while removing micro- and nano-sized particulates from solution. The desire to introduce an antibacterial function into water filter applications presents a challenge to widespread application of fibrous membranes because the addition of chemicals or biocides may produce harmful byproducts downstream. Here, we report the development of chitosan-polycaprolactone (PCL) nanofibrous membranes to utilize the natural antibacterial property of chitosan for antibacterial water filtration. Chitosan-PCL fibers with diameters of 200-400 nm and chitosan contents of 25, 50 and 75 wt% were prepared by electrospinning. In a series of bacterial challenge tests, chitosan-PCL fibrous membranes significantly reduced Staphylococcus aureus adhesion compared to PCL fibrous membranes. In water permeability and particulate size removal tests, fibrous membranes with 25% chitosan supported the greatest water flux (?7000 L/h/m(2)) with 100% removal of 300-nm particulates, while maintaining the membrane integrity. This study demonstrates the potential of chitosan-PCL nanofibrous membranes as pre-filters for water filtration systems that demonstrate combinatorial filtration and intrinsic antibacterial advantages. PMID:23218292

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

    PubMed Central

    de Lima, Jefferson Muniz; Sarmento, Ronaldo Rodrigues; de Souza, Joelma Rodrigues; Brayner, Fábio André; Feitosa, Ana Paula Sampaio; Padilha, Rafael; Alves, Luiz Carlos; Porto, Isaque Jerônimo; Batista, Roberta Ferreti Bonan Dantas; de Oliveira, Juliano Elvis; de Medeiros, Eliton Souto; Bonan, Paulo Rogério Ferreti; Castellano, Lúcio Roberto

    2015-01-01

    Chitosan is a polysaccharide composed of randomly distributed chains of ?-(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. PMID:25759815

  4. Remediation of coal mining wastewaters using chitosan microspheres.

    PubMed

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

    2003-12-01

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

  5. Biocompatibility and gelation of chitosan-glycerol phosphate hydrogels.

    PubMed

    Ahmadi, Raheleh; de Bruijn, Joost D

    2008-09-01

    The aim of this study was to evaluate the cytotoxicity and gelation of thermosensitive chitosan-beta-glycerol phosphate (GP) solutions, which undergo sol-gel transition around body temperature. Chitosan 0.5-2% (w/v) mixed with GP 5-20% (w/v) solutions all gel at 37 degrees C and possess pH around the physiological range. High GP and chitosan concentrations result in faster gelation time. Extracts of all chitosan concentrations mixed with or without 5% (w/v) GP and 2% (w/v) chitosan combined with 10% (w/v) GP demonstrated up to 34% increase in proliferation rate of goat bone marrow derived mesenchymal stem cells when compared with control medium. Extracts from all other chitosan-GP combinations resulted in reduced cell proliferation relative to control medium. Increasing GP content in the gel resulted in a linear increase in the osmolality of the extracts in contact with the gels. The results of this study indicate that chitosan-GP is a biocompatible hydrogel, extracts of which can stimulate mesenchymal stem cell proliferation at certain concentrations. This material is therefore a promising vehicle for cell encapsulation and injectable tissue-engineering applications. PMID:18041728

  6. Mechanism of arsenic removal using chitosan and nanochitosan.

    PubMed

    Kwok, Katrina C M; Koong, Len Foong; Chen, Guohua; McKay, Gordon

    2014-02-15

    Chitosan, a natural polysaccharide copolymer of glucosamine and N-acetyl-glucosamine, possesses one free primary amine and two free hydroxyl groups on each glucosamine unit. It has a polycationic nature and an abundance of amine functional groups. The sorption equilibrium and kinetics of arsenate onto chitosan flakes have been studied. The effect of pH on the adsorption capacity and the uptake kinetics is an important parameter to investigate the adsorption mechanism of anionic species such as arsenate ions on the protonated amine groups of chitosan. The equilibrium sorption and batch kinetic studies of arsenate ions on chitosan were performed at initial As concentration of 250-11,000 ?g L(-1) and initial pH ranging from pH=3.50-5.50. The experimental results showed that initially for approximately the first 30 min there is a rapid and high adsorption of arsenate ions onto the chitosan leading to a maximum uptake capacity after this short time. However, this stage is followed by a slow desorption of arsenate from the chitosan with a steady increase in solution pH. A novel reversible pseudo-first order kinetic model was developed and applied to correlate this newly reported adsorption-desorption phenomenon. The physical and chemical properties of chitosan were studied and presented in terms of its surface and structural properties such as the degree of deacetylation, crystallinity, surface charge and its swelling properties. PMID:24370394

  7. A quantitative study of MC3T3-E1 cell adhesion, morphology and biomechanics on chitosan-collagen blend films at single cell level.

    PubMed

    Wang, Chuang; Xie, Xu-Dong; Huang, Xun; Liang, Zhi-Hong; Zhou, Chang-Ren

    2015-08-01

    The interaction between cells and biomaterials plays a key role in cell proliferation and differentiation in tissue engineering. However, a quantitative analysis of those interactions has been less well studied. The objective of this study was to quantitative recapitulate the difference of MC3T3-E1 cell adhesion, morphological and biomechanical properties on chitosan-collagen films in terms of chemical composition. Here, the unbinding force between MC3T3-E1 cell and a series of chitosan-collagen films was probed by a real-time and in situ atomic force microscopy-single cell force spectroscopy (AFM-SCFS). Meanwhile, changes in cell morphology and Young's modulus on different chitosan-collagen films were detected by AFM. The cell area and CCK-8 results showed that cell spreading and proliferation increased with increasing collagen content. AFM observations clearly showed cell height decreased and pseudopod fusion with the collagen content increased. Cell adhesive force increased from 0.76±0.17nN to 1.70±0.19nN. On the contrary, cells Young's modulus, which reflected biophysical changes of cells decreased from 11.94±3.19kPa to 1.81±0.52kPa, respectively. It suggested that stronger cell-substrate interactions benefit cell adhesion, and better cell flexibility improve cell spreading. The findings indicate that cell morphology, adhesive force and Young's modulus are significant affected by various chitosan-collagen substrates. Those methods and quantitative results have guiding significance for investigating the mechanism of chitosan and/or collagen based cell-targeting drug carrier and the preparation of chitosan-collagen composite biomaterials. PMID:25996415

  8. Assembly of bioactive peptide-chitosan nanocomplexes.

    PubMed

    Hu, B; Wang, S S; Li, J; Zeng, X X; Huang, Q R

    2011-06-16

    The assembly of nanocomplexes from bioactive peptides, namely, caseinophosphopeptides (CPPs) and chitosan (CS), at physiological conditions and various CS/CPP mass ratios has been systematically studied using a combination of liquid chromatography-tandem mass spectrometry (LC-MS/MS), turbidimetric titration, dynamic light scattering (DLS), electrophoretic mobility (?-potential) measurements, transmission electron microscopy (TEM), and fluorescence spectroscopy. Peptides incorporated with CS forming nanoparticles were prepared and identified using LC-MS/MS. They were characterized by different amounts of clusters of phosphorylated seryl residues. At low salt concentrations, an increase in CS/CPP mass ratio shifted the critical pH(?1) value, which was designated as the formation of CS/CPP nanocomplexes, as well as pH(max), which represents the neutralization of positive and negative charges at higher pH values. The sizes, charges, morphologies, binding mechanisms, and binding constants of the bioactive peptide-chitosan nanocomplexes were analyzed, and our results suggest that three processes are involved in nanocomplex formation: First, negatively charged CPPs absorb to positively charged CS molecular chains to form intrapolymer nanocomplexes saturated with CPPs (CPPNPs). Subsequently, the negatively charged CPPNPs are bridged by the addition of positively charged CS, resulting in the formation of nearly neutral associative biopolymer complexes. Finally, further addition of excess chitosan breaks down the bridges of associative complexes and causes the formation of positively charged isolated spherical nanocomplexes. The binding between the peptides and CS is mainly driven by electrostatic interactions with a binding constant of K(cs) = 4.6 × 10(4) M(-1). Phosphorylated groups and other negatively charged amino acids, such as aspartic acid (Asp) and glutamic acid (Glu), in the CPPs might be the dominant sites for interaction with -NH(3)(+) groups on the CS molecular chains. PMID:21608974

  9. Production and isolation of chitosan from Mucor rouxii.

    PubMed Central

    White, S A; Farina, P R; Fulton, I

    1979-01-01

    A method for the lab-scale production and isolation of chitosan (polyglucosamine) from hyphal walls of Mucor rouxii was developed. Hyphal wall yields were generally 16 to 22% on a dry cell weight basis, of which 35 to 40% was glucosamine. Chitosan was readily extracted from purified, mycelial walls with acetic, formic, and hydrochloric acids; the last named was the most efficient. The yield of chitosan isolated ranged from 4 to 8% of the dry weight of the cell wall material. Images PMID:518086

  10. [Brucine chitosan thermosensitive hydrogel for intra-articular injection].

    PubMed

    Chen, Zhi-Peng; Liu, Wen; Chen, Hong-Xuan; Cai, Bao-Chang

    2012-05-01

    The aim of this study was to develop a sustained release converse thermosensitive hydrogel for intra-articular injection using chitosan-glycerol-borax as matrix, its physical properties and biocompatibility were investigated. Taking gelation time and gelation condition as index, the influence of concentration of chitosan, ratio of chitosan to glycerol, pH on physical properties of hydrogel were investigated. And then the in vitro drug release, rheological properties and biocompatibility were studied. The thermosensitive hydrogel flows easily at room temperature and turns to gelation at body temperature, which can certainly prolong the release of drug and has good biocompatibility. PMID:22812012

  11. Development of a gadolinium-loaded liquid scintillator for solar neutrino detection and neutron measurements

    Microsoft Academic Search

    P. K. Lightfoot; V. A. Kudryavtsev; N. J. C. Spooner; I. Liubarsky; R. Luscher; N. J. T. Smith

    2004-01-01

    A high flashpoint, low-toxicity liquid scintillator based on alpha-hydroxytoluene and containing 10wt% Gd has been developed for solar neutrino detection and neutron measurements. Dissolution of the gadolinium compound into the scintillator was facilitated by the use of the extractant triethylphosphate. Preliminary investigation has shown the attenuation length of the loaded scintillator to be 1.42m at 420nm and the light collection

  12. Development of a gadolinium-loaded liquid scintillator for solar neutrino detection and neutron measurements

    Microsoft Academic Search

    P. K. Lightfoot; V. A. Kudryavtseva; N. J. C. Spooner; I Liubarsky; R Luscher; N. J. T Smith

    2004-01-01

    A high flashpoint, low-toxicity liquid scintillator based on ?-hydroxytoluene and containing 10wt% Gd has been developed for solar neutrino detection and neutron measurements. Dissolution of the gadolinium compound into the scintillator was facilitated by the use of the extractant triethylphosphate. Preliminary investigation has shown the attenuation length of the loaded scintillator to be 1.42m at 420nm and the light collection

  13. Validation of a Janus role of methotrexate-based PEGylated chitosan nanoparticles in vitro

    PubMed Central

    2014-01-01

    Recently, methotrexate (MTX) has been used to target to folate (FA) receptor-overexpressing cancer cells for targeted drug delivery. However, the systematic evaluation of MTX as a Janus-like agent has not been reported before. Here, we explored the validity of using MTX playing an early-phase cancer-specific targeting ligand cooperated with a late-phase therapeutic anticancer agent based on the PEGylated chitosan (CS) nanoparticles (NPs) as drug carriers. Some advantages of these nanoscaled drug delivery systems are as follows: (1) the NPs can ensure minimal premature release of MTX at off-target site to reduce the side effects to normal tissue; (2) MTX can function as a targeting ligand at target site prior to cellular uptake; and (3) once internalized by the target cell, the NPs can function as a prodrug formulation, releasing biologically active MTX inside the cells. The (MTX?+?PEG)-CS-NPs presented a sustained/proteases-mediated drug release. More importantly, compared with the PEG-CS-NPs and (FA?+?PEG)-CS-NPs, the (MTX?+?PEG)-CS-NPs showed a greater cellular uptake. Furthermore, the (MTX?+?PEG)-CS-NPs demonstrated a superior cytotoxicity compare to the free MTX. Our findings therefore validated that the MTX-loaded PEGylated CS-NPs can simultaneously target and treat FA receptor-overexpressing cancer cells. PMID:25114653

  14. Validation of a Janus role of methotrexate-based PEGylated chitosan nanoparticles in vitro

    NASA Astrophysics Data System (ADS)

    Luo, Fanghong; Li, Yang; Jia, Mengmeng; Cui, Fei; Wu, Hongjie; Yu, Fei; Lin, Jinyan; Yang, Xiangrui; Hou, Zhenqing; Zhang, Qiqing

    2014-07-01

    Recently, methotrexate (MTX) has been used to target to folate (FA) receptor-overexpressing cancer cells for targeted drug delivery. However, the systematic evaluation of MTX as a Janus-like agent has not been reported before. Here, we explored the validity of using MTX playing an early-phase cancer-specific targeting ligand cooperated with a late-phase therapeutic anticancer agent based on the PEGylated chitosan (CS) nanoparticles (NPs) as drug carriers. Some advantages of these nanoscaled drug delivery systems are as follows: (1) the NPs can ensure minimal premature release of MTX at off-target site to reduce the side effects to normal tissue; (2) MTX can function as a targeting ligand at target site prior to cellular uptake; and (3) once internalized by the target cell, the NPs can function as a prodrug formulation, releasing biologically active MTX inside the cells. The (MTX + PEG)-CS-NPs presented a sustained/proteases-mediated drug release. More importantly, compared with the PEG-CS-NPs and (FA + PEG)-CS-NPs, the (MTX + PEG)-CS-NPs showed a greater cellular uptake. Furthermore, the (MTX + PEG)-CS-NPs demonstrated a superior cytotoxicity compare to the free MTX. Our findings therefore validated that the MTX-loaded PEGylated CS-NPs can simultaneously target and treat FA receptor-overexpressing cancer cells.

  15. Fabrication of biocompatible and mechanically reinforced graphene oxide-chitosan nanocomposite films

    PubMed Central

    2013-01-01

    Background Graphene oxide (GO)can be dispersed through functionalization, or chemically converted to make different graphene-based nanocomposites with excellent mechanical and thermal properties. Chitosan, a partially deacetylated derivative of chitin, is extensively used for food packaging, biosensors, water treatment, and drug delivery. GO can be evenly dispersed in chitosan matrix through the formation of amide linkages between them, which is different from previous reports focusing on preparing GO/chitosan nanocomposites through physical mixing. Results In this study, free-standing graphene oxide-chitosan (GO-chitosan) nanocomposite films have been prepared. The GO-chitosan films are biologically compatible and mechanically reinforced. Through the formation of amide linkages between GO’s carboxylic acid groups and chitosan's amine groups, GO could be evenly dispersed within the chitosan matrix. We also characterized the GO-chitosan composite films using element analysis, Fourier transform infrared spectroscopy, X-ray photo electron spectroscopy, differential scanning calorimetry, and thermo gravimetric analysis. Compared to pristine chitosan film, the tensile strength of GO-chitosan film is improved by 2.5 folds and Young’s modulus increases by nearly 4.6 folds. The glass transition temperature of GO-chitosan composite film shifts from 118°C to 158°C compared to the pristine chitosan, indicating its enhanced thermal stability. GO-chitosan composite film was also evaluated for its biocompatibility with C3H10T1/2 cells by in vitro fluorescent staining. The graphene oxide-reinforced chitosan composite films could have applications in functional biomaterials. Conclusion The present study describes a useful and simple method to chemically attach biocompatible chitosan onto graphene oxide. We envision that the GO-chitosan film will open avenues for next-generation graphene applications in the realm of functional biomaterial. PMID:23442350

  16. Inactivation of Heparin by Cationically Modified Chitosan

    PubMed Central

    Lorkowska-Zawicka, Barbara; Kami?ski, Kamil; Ciejka, Justyna; Szczubia?ka, Krzysztof; Bia?as, Magdalena; Oko?, Krzysztof; Adamek, Dariusz; Nowakowska, Maria; Jawie?, Jacek; Olszanecki, Rafa?; Korbut, Ryszard

    2014-01-01

    This study was performed to evaluate the ability of N-(2-hydroxypropyl)-3-trimethylammonium chitosan chloride (HTCC), the cationically modified chitosan, to form biologically inactive complexes with unfractionated heparin and thereby blocking its anticoagulant activity. Experiments were carried out in rats in vivo and in vitro using the activated partial thromboplastin time (APTT) and prothrombin time (PT) tests for evaluation of heparin anticoagulant activity. For the first time we have found that HTCC effectively neutralizes anticoagulant action of heparin in rat blood in vitro as well as in rats in vivo. The effect of HTCC on suppression of heparin activity is dose-dependent and its efficacy can be comparable to that of protamine-the only agent used in clinic for heparin neutralization. HTCC administered i.v. alone had no direct effect on any of the coagulation tests used. The potential adverse effects of HTCC were further explored using rat experimental model of acute toxicity. When administered i.p. at high doses (250 and 500 mg/kg body weight), HTCC induced some significant dose-dependent structural abnormalities in the liver. However, when HTCC was administered at low doses, comparable to those used for neutralization of anticoagulant effect of heparin, no histopathological abnormalities in liver were observed. PMID:24983639

  17. Chitosan-alginate membranes accelerate wound healing.

    PubMed

    Caetano, Guilherme Ferreira; Frade, Marco Andrey Cipriani; Andrade, Thiago Antônio Moretti; Leite, Marcel Nani; Bueno, Cecilia Zorzi; Moraes, Angela Maria; Ribeiro-Paes, João Tadeu

    2014-09-15

    The purpose of this study was to evaluate the efficacy of chitosan-alginate membrane to accelerate wound healing in experimental cutaneous wounds. Two wounds were performed in Wistar rats by punching (1.5 cm diameter), treated with membranes moistened with saline solution (CAM group) or with saline only (SL group). After 2, 7, 14, and 21 days of surgery, five rats of each group were euthanized and reepithelialization was evaluated. The wounds/scars were harvested for histological, flow cytometry, neutrophil infiltrate, and hydroxyproline analysis. CAM group presented higher inflammatory cells recruitment as compared to SL group on 2(nd) day. On the 7(th) day, CAM group showed higher CD11b(+) level and lower of neutrophils than SL group. The CAM group presented higher CD4(+) cells influx than SL group on 2(nd) day, but it decreased during the follow up and became lower on 14(th) and 21(st) days. Higher fibroplasia was noticed on days 7 and 14 as well as higher collagenesis on 21(st) in the CAM group in comparison to SL group. CAM group showed faster reepithelialization on 7(th) day than SL group, although similar in other days. In conclusion, chitosan-alginate membrane modulated the inflammatory phase, stimulated fibroplasia and collagenesis, accelerating wound healing process in rats. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2014. PMID:25220821

  18. Formation of spherical chitosan biocatalysts by ionotropic gelation

    Microsoft Academic Search

    K.-D. Vorlop; J. Klein

    1981-01-01

    A new immobilization method is described using the ionotropic gelation of a polycation (chitosan) with different multivalent anionic counterions. Immobilized E-coli cells with tryptophan synthetase show ~ 57 % of the initial activity.

  19. Properties of Novel Hydroxypropyl Methylcellulose Films Containing Chitosan Nanoparticles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this work, chitosan nanoparticles were prepared and incorporated in hydroxypropyl methylcellulose (HPMC) films under different conditions. Mechanical properties, water vapor and oxygen permeability, water solubility and scanning and transmission electron microscopy (SEM and TEM) results were ana...

  20. Development of a quaternized chitosan with enhanced antibacterial efficacy.

    PubMed

    Khaira, Gurpreet Kaur; Kumariya, Rashmi; Chibber, Manmohan; Ghosh, Moushumi

    2013-09-01

    The antibacterial activity of a water-soluble chitosan derivative prepared by chemical modification to quaternary ammonium compound N,N,N-trimethylchitosan (TC) was investigated against four selected waterborne pathogens: Aeromonas hydrophila ATCC 35654, Yersinia enterocolitica ATCC 9610, Listeria monocytogenes ATCC 19111 and Escherichia coli O157:H7 ATCC 32150. An inactivation of 4 log CFU/ml of all waterborne pathogens was noted for the quaternized chitosan as compared with chitosan over a short contact time (30 min) and low dosage (4.5 ppm) at ambient temperature. A marked increase in glucose level, protein content and lactate dehydrogenase (LDH) activity was observed concurrently in the cell supernatant to be a major bactericidal mechanism. The results suggest that the TC derivative may be a promising commercial substitute for acid-soluble chitosan for rapid and effective disinfection of water. PMID:23981870

  1. Structural and rheological properties of chitosan semi-interpenetrated networks.

    PubMed

    Payet, L; Ponton, A; Grossiord, J-L; Agnely, F

    2010-06-01

    The local structure and the viscoelastic properties of semi-interpenetrated biopolymer networks based on cross-linked chitosan and poly(ethylene oxide) (PEO) were investigated by Small Angle Neutron Scattering and rheological measurements. The specific viscosity and the entanglement concentration of chitosan were first determined, respectively, by capillary viscosimetry and steady-state shear rheology experiments performed at different polymer concentrations. Mechanical spectroscopy was then used to study the gelation process of chitosan/PEO semi-interpenetrated networks. By fitting the frequency dependence of the elastic and loss moduli with extended relations of relaxation shear modulus around the sol-gel transition, it was shown that the addition of PEO chains had a significant effect on the viscoelastic properties of aqueous chitosan networks but no effect on the gelation time. The improvement of mechanical properties was in accordance with the correlation length decrease deduced from Small Angle Neutron Scattering experiments. PMID:20526647

  2. Synergistic degradation of chitosan by impinging stream and jet cavitation.

    PubMed

    Huang, Yongchun; Wang, Pengfei; Yuan, Yuan; Ren, Xian'e; Yang, Feng

    2015-11-01

    Chitosan degradation was investigated using a combination of jet cavitation and impinging stream. Different operating parameters such as the initial concentration (1-5gL(-1)), initial pH (3.2-4.8), solution temperature (30, 40, 50, 60, and 70°C), inlet pressure (0.1-0.45MPa), and treatment time (0-120min) were optimized to achieve the maximum degradation of chitosan. After the optimization of jet cavitation parameters, chitosan degradation was carried out using venturi tubes of different structures (the fluidic generator). The efficiency of the jet cavitation degradation was improved significantly by combining with impinging stream. The structures of the degradation products were characterized by Fourier-transform infrared spectroscopy and X-ray diffraction. This study has conclusively established that a combination of jet cavitation and impinging stream can be effectively used for the complete degradation of chitosan. PMID:25934127

  3. Emerging chitin and chitosan nanofibrous materials for biomedical applications

    NASA Astrophysics Data System (ADS)

    Ding, Fuyuan; Deng, Hongbing; Du, Yumin; Shi, Xiaowen; Wang, Qun

    2014-07-01

    Over the past several decades, we have witnessed significant progress in chitosan and chitin based nanostructured materials. The nanofibers from chitin and chitosan with appealing physical and biological features have attracted intense attention due to their excellent biological properties related to biodegradability, biocompatibility, antibacterial activity, low immunogenicity and wound healing capacity. Various methods, such as electrospinning, self-assembly, phase separation, mechanical treatment, printing, ultrasonication and chemical treatment were employed to prepare chitin and chitosan nanofibers. These nanofibrous materials have tremendous potential to be used as drug delivery systems, tissue engineering scaffolds, wound dressing materials, antimicrobial agents, and biosensors. This review article discusses the most recent progress in the preparation and application of chitin and chitosan based nanofibrous materials in biomedical fields.

  4. Chitosan based oligoamine polymers: synthesis, characterization, and gene delivery.

    PubMed

    Lu, Bo; Wang, Chang-Fang; Wu, De-Qun; Li, Cao; Zhang, Xian-Zheng; Zhuo, Ren-Xi

    2009-07-01

    A series of chitosan-based oligoamine polymers was synthesized from N-maleated chitosan (NMC) via Michael addition with diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA) and linear polyethylenimine (M(n) 423), respectively. The resulted polymers exhibited well binding ability to condense plasmid DNA to form complexes with size ranging from 200 to 600 nm when the polymer/DNA weight ratio was above 7. The polymer/DNA complexes observed by scanning electron microscopy (SEM) exhibited a compact and spherical morphology. The cytotoxicity assay showed that the synthesized polymers were less toxic than that of PEI(25 K). The gene transfection effect of resulted polymers was evaluated in 293T and HeLa cells, and the results showed that the gene transfection efficiency of these polymers was better than that of chitosan. Moreover, the transfection efficiency was dependent on the length of the oligoamine side chains and the molecular weight of the chitosan derivatives. PMID:19303039

  5. Biodegradable chitosan nanoparticles in drug delivery for infectious disease.

    PubMed

    Landriscina, Angelo; Rosen, Jamie; Friedman, Adam J

    2015-05-01

    Increasing rates of antimicrobial resistance have left a significant gap in the standard antimicrobial armament. Nanotechnology holds promise as a new approach to combating resistant microbes. Chitosan, a form of deacetylated chitin, has been used extensively in medicine, agriculture and industry due to its ease of production, biocompatibility and antimicrobial activity. Chitosan has been studied extensively as a main structural component and additive for nanomaterials. Specifically, numerous studies have demonstrated its potent microbicidal activity and its efficacy as an adjuvant to vaccines, including mucosally administered vaccines. In this review, we present fundamental information about chitosan and chitosan nanoparticles as well as the most recent data about their antimicrobial mechanism and efficacy as a nanotechnology-based drug delivery system. PMID:26008195

  6. Intermolecular interactions in electrospun collagen–chitosan complex nanofibers

    Microsoft Academic Search

    Zonggang Chen; Xiumei Mo; Chuanglong He; Hongsheng Wang

    2008-01-01

    The collagen–chitosan complex nanofibers have been prepared here by electrospinning. Intermolecular interactions in electrospun collagen–chitosan complex fibers have been studied by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and the mechanical measurements of single ultrafine fiber. It was found that the –OH group, the –NH2 group and the amide I, II and III characteristic absorption bands in FT-IR

  7. Pullulan production by Aureobasidium pullulans cells immobilized in chitosan beads

    Microsoft Academic Search

    Thomas P. West

    Fungal cells of Aureobasidium pullulans ATCC 201253 were immobilized by entrapment in chitosan beads, and the immobilized cells were investigated for their ability\\u000a to produce the polysaccharide pullulan using batch fermentation. The 1% chitosan-entrapped fungal cells were capable of producing\\u000a pullulan for two cycles of 168 h using corn syrup as a carbon source. Pullulan production by the immobilized cells

  8. Enhanced Topical Delivery of Terbinafine Hydrochloride with Chitosan Hydrogels

    Microsoft Academic Search

    ?pek Özcan; Özlem Abac?; Alev Haliki Uztan; Buket Aksu; Hayal Boyac?o?lu; Tamer Güneri; Özgen Özer

    2009-01-01

    Chitosan-based carriers have important potential applications for the administration of drugs. In the present study, topical\\u000a gel formulations of terbinafine hydrochloride (T-HCl) were prepared using different types of chitosan at different molecular\\u000a weight, and the antifungal inhibitory activity was evaluated to suggest an effective formulation for the treatment of fungal\\u000a infections. The characteristics of gel formulations were determined with viscosity

  9. Effect of chitosan on Salmonella Typhimurium in broiler chickens.

    PubMed

    Menconi, Anita; Pumford, Neil R; Morgan, Marion J; Bielke, Lisa R; Kallapura, Gopala; Latorre, Juan D; Wolfenden, Amanda D; Hernandez-Velasco, Xochitl; Hargis, Billy M; Tellez, Guillermo

    2014-02-01

    Public concern with the incidence of antibiotic-resistant bacteria, particularly among foodborne pathogens such as Salmonella, has been challenging the poultry industry to find alternative means of control. The purposes of the present study were to evaluate in vitro and in vivo effects of chitosan on Salmonella enterica serovar Typhimurium (ST) infection in broiler chicks. For in vitro crop assay experiments, tubes containing feed, water, and ST were treated with either saline as a control or 0.2% chitosan. The entire assay was repeated in three trials. In two independent in vivo trials, 40 broiler chicks were assigned to an untreated control diet or dietary treatment with 0.2% chitosan for 7 days (20 broiler chicks/treatment). At day 4, chicks were challenged with 2×10? colony-forming units (CFU) ST/bird. In a third in vivo trial, 100 broiler chicks were assigned to untreated control diet or dietary treatment with 0.2% chitosan for 10 days (50 broiler chicks/treatment) to evaluate ST horizontal transmission. At day 3, 10 birds were challenged with 10? CFU ST/bird, and the remaining nonchallenged birds (n=40) were kept in the same floor pen. In all three in vitro trials, 0.2% chitosan significantly reduced total CFU of ST at 0.5 and 6?h postinoculation compared with control (p<0.05). In two in vivo trials, at 7 days, dietary 0.2% chitosan significantly reduced total CFU of recovered ST in the ceca in both experiments. Dietary 0.2% chitosan significantly reduced total ST CFU recovered in the ceca of horizontally challenged birds in the third in vivo trial. Chitosan at 0.2% significantly reduced the CFU of recovered ST in vitro and in vivo, proving to be an alternative tool to reduce crop, ceca, and consequently carcass ST contamination as well as decreasing the amount of ST shed to the environment. PMID:24237042

  10. Chitosan–chondroitin sulfate and chitosan–hyaluronate polyelectrolyte complexes: biological properties

    Microsoft Academic Search

    Anne Denuziere; Danielle Ferrier; Odile Damour; Alain Domard

    1998-01-01

    In this work, we compare some biological properties of a highly deacetylated chitosan to those obtained with the materials made from its polyelectrolyte complexes with various GAG’s such as chondroitin-sulfates and hyaluronic acid. The hydrolysis of the complexes by means of the specific hydrolytic enzymes is studied. Cell-adhesion and cell-proliferation on these materials is compared to that obtained with a

  11. Tri-layered chitosan scaffold as a potential skin substitute.

    PubMed

    Lin, Hsin-Yi; Chen, Shin-Hung; Chang, Shih-Hsin; Huang, Sheng-Tung

    2015-09-01

    A tri-layered chitosan-based scaffold was successfully made to replicate the striation of a full-thickness skin more accurately than a single- or bi-layered scaffold, which needed weeks of co-culturing of fibroblasts and keratinocytes to achieve similar striation. Chitosan solution was freeze-dried and made into porous disks. Chitosan or chitosan-pectin in acetic acid solution was electrospun onto the chitosan disk to form a nanofibrous layer and a thin film. Examinations based on scanning electron spectroscopy showed that the scaffold was composed of a porous layer (2 mm) to simulate the dermis, a thin film (25-45 ?m) to mimic the basement membrane, and a layer of nanofibers (100-200 ?m) to serve as the protective epidermis. The tensile strength and modulus of the composite scaffold were significantly higher than those of the chitosan disk (p < 0.01). The composite was able to quickly absorb water and stayed intact throughout the course of the 14-day cell culture tests. The fibroblast cells seeded on both sides of the scaffolds were able to proliferate and stayed separated by the thin film. PMID:26155720

  12. Complex coacervation of soybean protein isolate and chitosan.

    PubMed

    Huang, Guo-Qing; Sun, Yan-Ting; Xiao, Jun-Xia; Yang, Jian

    2012-11-15

    The formation of coacervates between soybean protein isolate (SPI) and chitosan was investigated by turbidimetric analysis and coacervate yield determination as a function of pH, temperature, time, ionic strength, total biopolymer concentration (TB(conc)) and protein to polysaccharide ratio (R(SPI/Chitosan)). The interaction between SPI and chitosan yielded a sponge-like coacervate phase and the optimum conditions for their coacervation were pH 6.0-6.5, a temperature of 25 °C, and a R(SPI/Chitosan) ratio of four independently of TB(conc). NaCl inhibited the complexation between the two biopolymers. Fourier transform infrared spectroscopy (FTIR) revealed that the coacervates were formed through the electrostatic interaction between the carboxyl groups of SPI (-COO(-)) and the amine groups of chitosan (-NH(3)(+)), however hydrogen bonding was also involved in the coacervation. Differential scanning calorimetry (DSC) thermograms indicated raised denaturation temperature and network thermal stability of SPI in the coacervates due to SPI-chitosan interactions. Scanning electron microscopy (SEM) micrographs revealed that the coacervates had a porous network structure interspaced by heterogeneously sized vacuoles. PMID:22868125

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

    PubMed

    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. PMID:25439934

  14. Preparation and evaluation of inhalable itraconazole chitosan based polymeric micelles

    PubMed Central

    2012-01-01

    Background This study evaluated the potential of chitosan based polymeric micelles as a nanocarrier system for pulmonary delivery of itraconazole (ITRA). Methods Hydrophobically modified chitosan were synthesized by conjugation of stearic acid to the hydrophilic depolymerized chitosan. FTIR and 1HNMR were used to prove the chemical structure and physical properties of the depolymerized and the stearic acid grafted chitosan. ITRA was entrapped into the micelles and physicochemical properties of the micelles were investigated. Fluorescence spectroscopy, dynamic laser light scattering and transmission electron microscopy were used to characterize the physicochemical properties of the prepared micelles. The in vitro pulmonary profile of polymeric micelles was studied by an air-jet nebulizer connected to a twin stage impinger. Results The polymeric micelles prepared in this study could entrap up to 43.2±2.27??g of ITRA per milliliter. All micelles showed mean diameter between 120–200?nm. The critical micelle concentration of the stearic acid grafted chitosan was found to be 1.58×10-2?mg/ml. The nebulization efficiency was up to 89% and the fine particle fraction (FPF) varied from 38% to 47%. The micelles had enough stability to remain encapsulation of the drug during nebulization process. Conclusions In vitro data showed that stearic acid grafted chitosan based polymeric micelles has a potential to be used as nanocarriers for delivery of itraconazole through inhalation. PMID:23351398

  15. Electrophoretic deposition of composite hydroxyapatite-silica-chitosan coatings

    SciTech Connect

    Grandfield, K. [Department of Materials Science and Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4L7 (Canada); Zhitomirsky, I. [Department of Materials Science and Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4L7 (Canada)], E-mail: zhitom@mcmaster.ca

    2008-01-15

    Electrophoretic deposition (EPD) method has been developed for the fabrication of nanocomposite silica-chitosan coatings. Cathodic deposits were obtained on various conductive substrates using suspensions of silica nanoparticles in a mixed ethanol-water solvent, containing dissolved chitosan. Co-deposition of silica and hydroxyapatite (HA) nanoparticles resulted in the fabrication of HA-silica-chitosan coatings. The deposition yield has been studied at a constant voltage mode at various deposition durations. The method enabled the formation of coatings of different thickness in the range of up to 100 {mu}m. Deposit composition, microstructure and porosity can be varied by variation of HA and silica concentration in the suspensions. It was demonstrated that EPD can be used for the fabrication of HA-silica-chitosan coatings of graded composition and laminates. The method enabled the deposition of coatings containing layers of silica-chitosan and HA-chitosan nanocomposites using suspensions with different HA and silica content. Obtained coatings were studied by X-ray diffraction, thermogravimetric and differential thermal analysis, scanning electron microscopy and energy dispersive spectroscopy. The mechanism of deposition is discussed.

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

    NASA Astrophysics Data System (ADS)

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

    2009-03-01

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

  17. Stability of Chitosan—A Challenge for Pharmaceutical and Biomedical Applications

    PubMed Central

    Szyma?ska, Emilia; Winnicka, Katarzyna

    2015-01-01

    Chitosan—one of the natural multifunctional polymers—due to its unique and versatile biological properties is regarded as a useful compound in medical and pharmaceutical technology. Recently, considerable research effort has been made in order to develop safe and efficient chitosan products. However, the problem of poor stability of chitosan-based systems restricts its practical applicability; thus, it has become a great challenge to establish sufficient shelf-life for chitosan formulations. Improved stability can be assessed by controlling the environmental factors, manipulating processing conditions (e.g., temperature), introducing a proper stabilizing compound, developing chitosan blends with another polymer, or modifying the chitosan structure using chemical or ionic agents. This review covers the influence of internal, environmental, and processing factors on the long-term stability of chitosan products. The aim of this paper is also to highlight the latest developments which enable the physicochemical properties of chitosan-based applications to be preserved upon storage. PMID:25837983

  18. Chitosan and cyclodextrin in intranasal microemulsion for improved brain buspirone hydrochloride pharmacokinetics in rats.

    PubMed

    Bshara, Hamza; Osman, Rihab; Mansour, Samar; El-Shamy, Abd El-Hameed A

    2014-01-01

    The aim of this study was to develop buspirone hydrochloride microemulsion formulations for intranasal administration to improve the drug bioavailability and provide high drug brain levels. For the purpose, chitosan aspartate, and hydroxypropyl-?-cyclodextrin were incorporated in the microemulsions. The prepared formulations were characterized. Biological investigations including pharmacokinetic studies, brain drug targeting efficiency determinations and histopathological examinations were performed on rats. The results showed that safe and stable mucoadhesive microemulsion suitable for nasal administration were successfully prepared. Ex vivo drug permeation revealed high drug permeation from microemulsions. Absolute bioavailability after intranasal administration of buspirone mucoadhesive microemulsion increased significantly and plasma concentration peaked at 15 min. The AUC0-360(brain) was 3 times that obtained after intravenous administration. A high brain targeting efficiency (86.6%) and a direct nose to brain transport (88%) confirmed the direct nose to brain transport of buspirone following nasal administration of the microemulsions. PMID:24274510

  19. Transactivator of transcription (TAT) peptide– chitosan functionalized multiwalled carbon nanotubes as a potential drug delivery vehicle for cancer therapy

    PubMed Central

    Dong, Xia; Liu, Lanxia; Zhu, Dunwan; Zhang, Hailing; Leng, Xigang

    2015-01-01

    Carbon nanotube (CNT)-based drug delivery vehicles might find great potential in cancer therapy via the combination of chemotherapy with photothermal therapy due to the strong optical absorbance of CNTs in the near-infrared region. However, the application of CNTs in cancer therapy was considerably constrained by their lack of solubility in aqueous medium, as well as the cytotoxicity caused by their hydrophobic surface. Intracellular delivery efficiency is another factor determining the application potential of CNTs in cancer therapy. In the present study, low-molecular-weight chitosan conjugated with transactivator of transcription (TAT) peptide was used for noncovalent functionalization of multiwalled carbon nanotubes (MWCNTs), aiming at providing a more efficient drug delivery vehicle for cancer therapy. The TAT–chitosan-conjugated MWCNTs (MWCNTs-TC) were further investigated for their water solubility, cytotoxicity, cell-penetrating capability, and accumulation in tumor. It was found that MWCNTs-TC were essentially nontoxic with satisfying water solubility, and they were more efficient in terms of cancer-targeted intracellular transport both in vitro and in vivo as compared with chitosan-modified MWCNTs (MWCNTs-CS), suggesting the great application potential of MWCNTs-TC in cancer therapy.

  20. Hypoglycemic efficacy of chitosan-coated insulin liposomes after oral administration in mice1

    Microsoft Academic Search

    Zheng-hong WU; Qi-neng PING; Yi WEI; Jia-ming LAI

    AIM: To evaluate the hypoglycemic efficacy of insulin liposomes coated by chitosan with different molecular weights and concentrations after oral administration in mice. METHODS: Insulin-liposomes were prepared by reversed-phase evaporation. Chitosan coating was carried out by incubation of the liposomal suspensions with the chitosan solution. The hypoglycemic efficacies of chitosan-coated insulin liposomes were investigated by monitor- ing the blood glucose

  1. Chitosan-DNA nanoparticles as gene carriers: synthesis, characterization and transfection efficiency

    Microsoft Academic Search

    Hai-Quan Mao; Krishnendu Roy; Vu L. Troung-Le; Kevin A. Janes; Kevin Y. Lin; Yan Wang; J. Thomas August; Kam W. Leong

    2001-01-01

    Chitosan-DNA nanoparticles were prepared using a complex coacervation process. The important parameters for the nanoparticle synthesis were investigated, including the concentrations of DNA, chitosan and sodium sulfate, temperature of the solutions, pH of the buffer, and molecular weights of chitosan and DNA. At an amino group to phosphate group ratio (N\\/P ratio) between 3 and 8 and a chitosan concentration

  2. Synthesis of chitosan derivatives with quaternary ammonium salt and their antibacterial activity

    Microsoft Academic Search

    Chun Ho Kim; Jang Won Choi; Heung Jae Chun; Kyu Suk Choi

    1997-01-01

    Summary  \\u000a N-alkyl chitosan derivatives were prepared by introducing alkyl groups into the amine groups of chitosan via Schiff’s base\\u000a intermediates. Quaternization of the N-alkyl chitosan derivatives were carried out using methyl iodide to produce water soluble cationic polyelectrolytes, novel\\u000a chitosan derivatives with quaternary ammonium salt. Their antibacterial activities against S. aureus were explored by the viable cell counting method in

  3. Use of Modified Chitosan Macrospheres in the Selective Removal of Immunoglobulins

    Microsoft Academic Search

    Anuradha Subramanian; Swapan Roy; Carmine Mascoli; Jennifer Hommerding

    2005-01-01

    A solution of chitosan in acetic acid was atomized into sodium hydroxide solution to yield chitosan beads that were 400–600 µm in diameter and with a solids content of 3.5%. Chitosan beads were modified to include a spacer arm and end?capped with a carboxyethyl?group containing anionic ligand to generate a support for use in bioseparations. The ligand modified chitosan beads will

  4. The Shape Memory Properties of Biodegradable Chitosan\\/Poly( l -lactide) Composites

    Microsoft Academic Search

    Qinghao MengJinlian; Jinlian Hu; KaiChiu Ho; Fenglong Ji; Shaojun Chen

    2009-01-01

    The shape memory behavior of PLLA (poly(l-lactide)) and chitosan\\/PLLA composites was studied. PLLA and chitosan were compounded to fabricate novel materials which\\u000a may have biodegradability and biocompatibility. Chitosan does not significantly affect the glass and melting transition temperature\\u000a of the PLLA. Both the pure PLLA and chitosan\\/PLLA composites showed shape memory effect arising from the viscoelastic properties\\u000a of PLLA comprised

  5. Enzymatic modification of chitosan with quercetin and its application as antioxidant edible films.

    PubMed

    Torres, E; Marín, V; Aburto, J; Beltrán, H I; Shirai, K; Villanueva, S; Sandoval, G

    2012-01-01

    Quercetin, rutin, naringin, hesperidin and chrysin were tested as substrates for chloroperoxidase to produce reactive quinones to graft onto chitosan. Quercetin and rutin quinones were successfully chemically attached to low molecular weight chitosan. The quercetin-modified chitosan showed an enhancement of plastic, antioxidant and antimicrobial properties as well as of thermal degradability. Finally, chitosan-quercetin films visibly decreased enzymatic oxidation when applied to Opuntia ficus indica cladodes. PMID:22586910

  6. Identification of yeast genes that confer resistance to chitosan oligosaccharide (COS) using chemogenomics

    PubMed Central

    2012-01-01

    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 trafficking, provides protection against COS-induced cell membrane permeability and damage. We found that the ARL1 COS-resistant over-expression strain was as sensitive to Amphotericin B, Fluconazole and Terbinafine as the wild type cells and that when COS and Fluconazole are used in combination they act in a synergistic fashion. The gene targets of COS identified in this study indicate that COS’s mechanism of action is different from other commonly studied fungicides that target membranes, suggesting that COS may be an effective fungicide for drug-resistant fungal pathogens. PMID:22727066

  7. RESEARCH PAPER Chitosan Film Containing Poly(D,L-Lactic-Co-Glycolic

    E-print Network

    Sridhar, Srinivas

    -drug release. KEY WORDS chitosan . PLGA . paclitaxel . drug release . implants coating INTRODUCTION Chitosan­9). The polymeric coating of biomedical implants like stents, tumor markers, catheters and pacemakers has emerged. Conclusions The ability of chitosan film containing PLGA NPs to coat gold surface and to incorporate

  8. Solid lipid nanoparticles modified with chitosan oligosaccharides for the controlled release of doxorubicin

    Microsoft Academic Search

    Xiao-Ying Ying; Dan Cui; Lian Yu; Yong-Zhong Du

    2011-01-01

    Solid lipid nanoparticles (SLN) modified with chitosan oligosaccharide was prepared by solvent diffusion method and subsequent ionic interaction. Using doxorubicin as a model drug, the effects of amount and molecular weight of chitosan oligosaccharide, and its crosslink degree by glutaraldehyde on the physicochemical properties of nanoparticles were investigated. After modification with chitosan oligosaccharide, the zeta potential of nanoparticles changed from

  9. Fiber-Based Chitosan Tubular Scaffolds for Soft Tissue Engineering: Fabrication and in Vitro Evaluation

    Microsoft Academic Search

    Aijun Wang; Qiang Ao; Wenling Cao; Chang Zhao; Yandao Gong; Nanming Zhao; Xiufang Zhang

    2005-01-01

    Porous, two-ply tubular chitosan conduits for guided tissue regeneration were fabricated by combining the textile technique (inner layer) with the thermally induced phase separation process (outer layer). A hollow chitosan tube was prepared using an industrial warp knitting process with chitosan yarns. Then, an appropriate diameter mandrel was inserted into the pre-fabricated tube. The tube and the mandrel were dipped

  10. Adsorption of Hexavalent Chromium on Chitosan Beads: Sorption Isotherms and Kinetics

    Microsoft Academic Search

    SANDRINE BOSINCO; ERIC GUIBAL; JEAN ROUSSY; PIERRE LECLOIREC

    1998-01-01

    Chitosan is a biopolymer that is usually obtained in a flaked form, nonporous and partially soluble in acidic media. The low porosity of the polymer introduces diffusion constraints which are rate limiting. Modifying the structure of the chitosan is a way to improve the accessibility of the adsorption sites. In this study, the modifications were carried out by dissolving chitosan

  11. Formulation pH Modulates the Interaction of Insulin with Chitosan Nanoparticles

    E-print Network

    Yeoh, Hock Hin

    Formulation pH Modulates the Interaction of Insulin with Chitosan Nanoparticles ZENGSHUAN MA,1 HOCK studies on chitosan-insulin nanoparticles have reported diverse encapsulation efficiency and insulin the efficiency and mechanism of asso- ciation of insulin with chitosan nanoparticles in the pH range of 2.3 to 6

  12. Antimicrobial peptide shows enhanced activity and reduced toxicity upon grafting to chitosan polymers.

    PubMed

    Sahariah, Priyanka; Sørensen, Kasper K; Hjálmarsdóttir, Martha Á; Sigurjónsson, Ólafur E; Jensen, Knud J; Másson, Már; Thygesen, Mikkel B

    2015-07-25

    Here we report that grafting of a short antimicrobial peptide, anoplin, to chitosan polymers is a strategy for abolishing the hemolytic propensity, and at the same time increasing the activity of the parent peptide. Anoplin-chitosan conjugates were synthesized by CuAAC reaction of multiple peptides through 2-azidoacetyl groups on chitosan. PMID:26096124

  13. The antifungal properties of chitosan in laboratory media and apple juice

    Microsoft Academic Search

    S. Roller; N. Covill

    1999-01-01

    The antimicrobial properties of chitosan glutamate, a derivative of chitin, were investigated in laboratory media and apple juice against 15 yeasts and moulds associated with food spoilage in order to assess the potential for using chitosan as a natural food preservative. Of the seven strains of filamentous fungi studied, chitosan reduced the growth rate of Mucor racemosus at 1 g\\/l

  14. Inactivation of Salmonella on whole cantaloupe by application of an antimicrobial coating containing chitosan and allyl isothiocyanate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study investigated the antimicrobial effect of a chitosan coating + allyl isothiocyanate (AIT) and nisin against Salmonella on whole fresh cantaloupes. Cantaloupes were inoculated with a cocktail of three Salmonella strains and treated with chitosan, chitosan + AIT, chitosan + nisin, and chitos...

  15. Effects of removing small fragments with ultrafiltration treatment and ultrasonic conditions on the degradation kinetics of chitosan

    Microsoft Academic Search

    Min Larng Tsaih; Lan Zang Tseng; Rong Huei Chen

    2004-01-01

    The objective of this study was to explore the effect of removing smaller degraded molecules with ultrafiltration treatment and ultrasonic conditions on the degradation kinetics of chitosan. The following results were obtained. The molecular weight of chitosan decreased faster for dilute chitosan solutions than for higher-concentration ones, and it decreased with sonolysis time. The molecular weights of chitosan solutions treated

  16. Zwitterionic Chitosan-Polyamidoamine Dendrimer Complex Nanoparticles as a pH-Sensitive Drug Carrier

    PubMed Central

    Liu, Karen C.; Yeo, Yoon

    2013-01-01

    Polyamidoamine (PAMAM) dendrimers have been widely explored as carriers of therapeutics and imaging agents. However, amine-terminated PAMAM dendrimers is rarely utilized in systemic applications due to its cytotoxicity and risk of opsonization, caused by its cationic charges. Such undesirable effects may be mitigated by shielding the PAMAM dendrimer surface with polymers that reduce the charges. However, this shielding may also interfere with PAMAM dendrimers’ ability to interact with target cells, thus reducing cellular uptake and overall efficacy of the delivery system. Therefore, we propose to use zwitterionic chitosan (ZWC), a new chitosan derivative, which has a unique pH-sensitive charge profile, as an alternative biomaterial to modify the cationic surface of PAMAM dendrimers. Stable electrostatic complex of ZWC and PAMAM dendrimers was formed at pH 7.4, where the PAMAM dendrimer surface was covered with ZWC, as demonstrated by fluorescence spectroscopy and transmission electron microscopy. The presence of ZWC coating protected red blood cells and fibroblast cells from hemolytic and cytotoxic activities of PAMAM dendrimers, respectively. Confocal microscopy showed that the protective effect of ZWC disappeared at low pH as the complex dissociated due to the charge conversion of ZWC, allowing PAMAM dendrimers to enter cells. These results demonstrate that ZWC is able to provide a surface coverage of PAMAM dendrimers in a pH-dependent manner and, thus, enhance the utility of PAMAM dendrimers as a drug carrier to solid tumors with acidifying microenvironment. PMID:23510114

  17. Chitosan/interfering RNA nanoparticle mediated gene silencing in disease vector mosquito larvae.

    PubMed

    Zhang, Xin; Mysore, Keshava; Flannery, Ellen; Michel, Kristin; Severson, David W; Zhu, Kun Yan; Duman-Scheel, Molly

    2015-01-01

    Vector mosquitoes inflict more human suffering than any other organism-and kill more than one million people each year. The mosquito genome projects facilitated research in new facets of mosquito biology, including functional genetic studies in the primary African malaria vector Anopheles gambiae and the dengue and yellow fever vector Aedes aegypti. RNA interference- (RNAi-) mediated gene silencing has been used to target genes of interest in both of these disease vector mosquito species. Here, we describe a procedure for preparation of chitosan/interfering RNA nanoparticles that are combined with food and ingested by larvae. This technically straightforward, high-throughput, and relatively inexpensive methodology, which is compatible with long double stranded RNA (dsRNA) or small interfering RNA (siRNA) molecules, has been used for the successful knockdown of a number of different genes in A. gambiae and A. aegypti larvae. Following larval feedings, knockdown, which is verified through qRT-PCR or in situ hybridization, can persist at least through the late pupal stage. This methodology may be applicable to a wide variety of mosquito and other insect species, including agricultural pests, as well as other non-model organisms. In addition to its utility in the research laboratory, in the future, chitosan, an inexpensive, non-toxic and biodegradable polymer, could potentially be utilized in the field. PMID:25867635

  18. Genipin-cross-linked fucose-chitosan/heparin nanoparticles for the eradication of Helicobacter pylori.

    PubMed

    Lin, Yu-Hsin; Tsai, Shih-Chang; Lai, Chih-Ho; Lee, Che-Hsin; He, Zih Sian; Tseng, Guan-Chin

    2013-06-01

    Helicobacter pylori is a significant human pathogen that recognizes specific carbohydrate receptors, such as the fucose receptor, and produces the vacuolating cytotoxin, which induces inflammatory responses and modulates the cell-cell junction integrity of the gastric epithelium. The clinical applicability of topical antimicrobial agents was needed to complete the eradication of H. pylori in the infected fundal area. In the present study, we combined fucose-conjugated chitosan and genipin-cross-linking technologies in preparing multifunctional genipin-cross-linked fucose-chitosan/heparin nanoparticles to encapsulate amoxicillin of targeting and directly make contact with the region of microorganism on the gastric epithelium. The results show that the nanoparticles effectively reduced drug release at gastric acids and then released amoxicillin in an H. pylori survival situation to inhibit H. pylori growth and reduce disruption of the cell-cell junction protein in areas of H. pylori infection. Furthermore, with amoxicillin-loaded nanoparticles, a more complete H. pylori clearance effect was observed, and H. pylori-associated gastric inflammation in an infected animal model was effectively reduced. PMID:23499480

  19. Applications of chitosan for improvement of quality and shelf life of foods: a review.

    PubMed

    No, H K; Meyers, S P; Prinyawiwatkul, W; Xu, Z

    2007-06-01

    Chitosan is a modified, natural biopolymer derived by deacetylation of chitin, a major component of the shells of crustacean. Recently, chitosan has received increased attention for its commercial applications in the biomedical, food, and chemical industries. Use of chitosan in food industry is readily seen due to its several distinctive biological activities and functional properties. The antimicrobial activity and film-forming property of chitosan make it a potential source of food preservative or coating material of natural origin. This review focuses on the applications of chitosan for improvement of quality and shelf life of various foods from agriculture, poultry, and seafood origin. PMID:17995743

  20. High concentration honey chitosan electrospun nanofibers: biocompatibility and antibacterial effects.

    PubMed

    Sarhan, Wessam A; Azzazy, Hassan M E

    2015-05-20

    Honey nanofibers represent an attractive formulation with unique medicinal and wound healing advantages. Nanofibers with honey concentrations of <10% were prepared, however, there is a need to prepare nanofibers with higher honey concentrations to increase the antibacterial and wound healing effects. In this work, chitosan and honey (H) were cospun with polyvinyl alcohol (P) allowing the fabrication of nanofibers with high honey concentrations up to 40% and high chitosan concentrations up to 5.5% of the total weight of the fibers using biocompatible solvents (1% acetic acid). The fabricated nanofibers were further chemically crosslinked, by exposure to glutaraldehyde vapor, and physically crosslinked by heating and freezing/thawing. The new HP-chitosan nanofibers showed pronounced antibacterial activity against Staphylococcus aureus but weak antibacterial activity against Escherichia coli. The developed HP-chitosan nanofibers revealed no cytotoxicity effects on cultured fibroblasts. In conclusion, biocompatible, antimicrobial crosslinked honey/polyvinyl alcohol/chitosan nanofibers were developed which hold potential as effective wound dressing. PMID:25817652

  1. Morphological and surface properties of electrospun chitosan nanofibers.

    PubMed

    Desai, Keyur; Kit, Kevin; Li, Jiajie; Zivanovic, Svetlana

    2008-03-01

    Nonwoven fiber mats of chitosan with potential applications in air and water filtration were successfully made by electrospinning of chitosan and poly(ethyleneoxide) (PEO) blend solutions. Electrospinning of pure chitosan was hindered by its limited solubility in aqueous acids and high degree of inter- and intrachain hydrogen bonding. Nanometer-sized fibers with fiber diameter as low as 80 +/- 35 nm without bead defects were made by electrospinning high molecular weight chitosan/PEO (95:5) blends. Fiber formation was characterized by fiber shape and size and was found to be strongly governed by the polymer molecular weight, blend ratios, polymer concentration, choice of solvent, and degree of deacetylation of chitosan. Weight fractions of polymers in the electrospun nonwoven fibers mats were determined by thermal gravimetric analysis and were similar to ratio of polymers in the blend solution. Surface properties of fiber mats were determined by measuring the binding efficiency of toxic heavy metal ions like chromium, and they were found to be related with fiber composition and structure. PMID:18198844

  2. Correlation of chitosan's rheological properties to its ability to electrospin

    NASA Astrophysics Data System (ADS)

    Krause, Wendy E.; Queen, Hailey A.; Klossner, Rebecca R.; Coughlin, Andrew J.

    2007-03-01

    Chitosan, derived from chitin found in the exoskeleton of crustaceans, has been investigated extensively for use in biomedical applications ranging from drug delivery to scaffolds for tissue engineering. Therefore, forming nanofibers of this linear polysaccharide is desirable for use in such applications, because the nanofibers can be tailored to mimic the size and porosity of the extracellular matrix. Electrostatic spinning (electrospinning) is a convenient method to produce nonwoven mats of nanofibers. The ability of the solutions to successfully electospin is closely correlated with the rheological properties of the solutions. Chitosan is challenging to electrospin due to its relatively high viscosity at modest concentrations. Solutions of chitosan blended with poly(ethylene oxide) (PEO) have been electrospun successfully with freshly prepared solutions. If the blended solutions are stored, they do not readily electrospin. Moreover, chitosan/PEO blend solutions show a drastic decrease in zero shear rate viscosity over time, which can be attributed to phase separation. The challenges associated with electrospinning charged biopolymers (chitosan is cationic) will be discussed in terms of their rheological properties. Successes and failures will be highlighted and compared results for readily electrospun neutral polymers.

  3. Chitosan-lithium triflate electrolyte in secondary lithium cells

    NASA Astrophysics Data System (ADS)

    Morni, N. M.; Arof, A. K.

    Films prepared from high molecular weight chitosan are shown to exhibit the highest electrical conductivity of 2.14×10 -7 S cm -1. The electrical conductivity is further enhanced to 1.03×10 -5 S cm -1 when ethylene carbonate (EC) is used as a plasticizer. X-ray diffraction (XRD) shows that EC disrupts the crystalline nature of chitosan acetate. Infrared (IR) spectroscopy reveals a shift in the amide band from 1590 to 1575 cm -1 on addition of LiCF 3SO 3. A film with a (chitosan+0.4 g EC) to LiCF 3SO 3 ratio of 80:20 gives the highest electrical conductivity of 3.0×10 -4 S cm -1. This film is used as an electrolyte for the fabrication of chitosan-based secondary cells, viz., Li/chitosan-EC-LiCF 3SO 3/V 2O 5. The characteristics of the cells are presented in this paper.

  4. Cartilage regeneration by novel polyethylene oxide/chitin/chitosan scaffolds.

    PubMed

    Kuo, Yung-Chih; Ku, I-Nan

    2008-10-01

    This study presents the application of novel PEO/chitin/chitosan scaffolds for the cultivation of bovine knee chondrocytes (BKCs). The results reveled that the composition strongly affected physicochemical characteristics of the ternary scaffolds. Based on the contours of porosity, the percentage of void space in these scaffolds was estimated to be higher than 90%. In regard to mechanical strength, the composition of 50% chitin and 50% chitosan in the scaffold led to the maximum of Young's modulus. Moreover, large extensibility of the scaffolds occurred at the following range of the composition: PEO > 37.5%, chitin < 25%, and chitosan <62.5%. After cultivation of BKCs over 4 weeks, the percentage of biodegradation was normally between 30 and 60%. The formation of neocartilage was assessed by the amounts of BKCs, glycosaminoglycans and collagens in the cultured BKC-polymer constructs. Better chondrogenesis was obtained at the following range of the composition: 25% < PEO < 40%, 12.5% < chitin < 37.5%, and 30% < chitosan < 50%. Thus, the regeneration of cartilaginous components could be manipulated simply by controlling the composition of PEO, chitin, and chitosan in the hybrid scaffolds. PMID:18771317

  5. Elastic chitosan conduits with multiple channels and well defined microstructure.

    PubMed

    Zhu, Jixiang; Xiong, Yi; Zeng, Chenguang; Qiang, Na; Quan, Daping; Wan, Jun

    2012-01-01

    Four kinds of chitosan conduits with longitudinal multi-channels and controlled internal microstructures were prepared using a special mold and a freeze-drying method. One of the conduits was fabricated from a chitosan solution (ab NC), while the other three groups were made from a pre-gelled chitosan solution using genipin as a chemical cross-linker (ab gNC), dibasic sodium phosphate as a physical cross-linker (ab pNC) or a combined ionic and covalent co-cross-linker (ab gpNC), respectively. The porosity of the chitosan conduits ranged from 88 to 90%. The gpNC showed highly interconnected and uniformly distributed pores compared to NC, the gNC and pNC. In contrast, the gNC and gpNC showed about 10% of the volume swelling ratio in 37°C PBS solution, although the gpNC scaffold's water uptake was the highest, at more than 17 times its original mass. Compressive tests showed that gpNC had significant elasticity and maintained its physical integrity even after compressing them down to 20% of their original height. The elastic modulus of gpNC reached 80 kPa, which was more than twice that of the other groups. Adhesion and proliferation of PC12 cells on chitosan gpNC scaffolds showed excellent properties by MTT and SEM observation, which indicated the potential of gpNC scaffolds for nerve tissue engineering applications. PMID:22561741

  6. Immobilization of Glucose Oxidase in Alginate-Chitosan Microcapsules

    PubMed Central

    Wang, Xia; Zhu, Ke-Xue; Zhou, Hui-Ming

    2011-01-01

    In order to improve its stability and catalytic rate in flour, the immobilization of glucose oxidase (GOX) was investigated in this work. The enzyme was encapsulated in calcium alginate-chitosan microspheres (CACM) using an emulsification-internal gelation-GOX adsorption-chitosan coating method. The interaction between alginate and chitosan was confirmed by infrared spectroscopy (IR). The resultant CACM in wet state, whose morphology was investigated by scanning electron microscopy (SEM), was spherical with a mean diameter of about 26 ?m. The GOX load, encapsulation efficiency and activity of the CACM-GOX were influenced by concentration of chitosan, encapsulation time and encapsulation pH. The highest total enzymatic activity and encapsulation efficiency was achieved when the pH of the adsorption medium was near the isoelectric point (pI) of GOX, approximately pH 4.0. In addition, the molecular weight of chitosan also evidently influenced the encapsulation efficiency. Storage stabilities of GOX samples were investigated continuously over two months and the retained activity of CACM-GOX was 70.4%, markedly higher than the 7.5% of free enzyme. The results reveal the great potential of CACM-GOX as a flour improver. PMID:21686168

  7. Enhanced topical delivery of terbinafine hydrochloride with chitosan hydrogels.

    PubMed

    Ozcan, Ipek; Abaci, Ozlem; Uztan, Alev Haliki; Aksu, Buket; Boyacio?lu, Hayal; Güneri, Tamer; Ozer, Ozgen

    2009-01-01

    Chitosan-based carriers have important potential applications for the administration of drugs. In the present study, topical gel formulations of terbinafine hydrochloride (T-HCl) were prepared using different types of chitosan at different molecular weight, and the antifungal inhibitory activity was evaluated to suggest an effective formulation for the treatment of fungal infections. The characteristics of gel formulations were determined with viscosity measurements and texture profile analysis. Stability studies were performed at different temperatures during 3 months. The ex vivo permeation properties were studied through rat skin by using Franz diffusion cells. The antifungal inhibitory activity of formulations on Candida species and filamentous fungi was also examined with agar-cup method. The microbiological assay was found suitable for determination of in vitro antifungal activity of T-HCl. A marketed product was used to compare the results. The antifungal activity of T-HCl significantly increased when it was introduced into the chitosan gels. A higher drug release and the highest zone of inhibition were obtained from gels prepared with the lowest molecular weight chitosan (Protasan UP CL 213) compared to that of other chitosan gels and marketed product. These results indicated the advantages of the suggested formulations for topical antifungal therapy against Candida species and filamentous fungi. PMID:19662536

  8. Docetaxel loaded chitosan nanoparticles: formulation, characterization and cytotoxicity studies.

    PubMed

    Jain, Ankit; Thakur, Kanika; Kush, Preeti; Jain, Upendra K

    2014-08-01

    The primary objective of the present investigation was to explore biodegradable chitosan as a polymeric material for formulating docetaxel nanoparticles (DTX-NPs) to be used as a delivery system for breast cancer treatment. Docetaxel loaded chitosan nanoparticles were formulated by water-in-oil nanoemulsion system and characterized in terms of particle size, zeta potential, polydispersity index, drug entrapment efficiency (EE), loading capacity (LC), scanning electron microscopy (SEM), in vitro release study and drug release kinetics. Further, to evaluate the potential anticancer efficacy of docetaxel loaded chitosan nanoparticulate system, in vitro cytotoxicity studies on human breast cancer cell line (MDA-MB-231) were carried out. The morphological studies revealed the spherical shape of docetaxel loaded chitosan nanoparticles having an average size of 170.1±5.42-227.6±7.87nm, polydispersity index in the range of 0.215±0.041-0.378±0.059 and zeta potential between 28.3 and 31.4mV. Nanoparticles exhibited 65-76% of drug entrapment and 8-12% loading capacity releasing about 68-83% of the drug within 12h following Higuchi's square-root kinetics. An increase of 20% MDA-MB-231 cell line growth inhibition was determined by docetaxel loaded chitosan nanoparticles with respect to the free drug after 72h incubation. PMID:24971551

  9. In vitro insulin release from thermosensitive chitosan hydrogel.

    PubMed

    Khodaverdi, Elham; Tafaghodi, Mohsen; Ganji, Fariba; Abnoos, Khalil; Naghizadeh, Hanie

    2012-06-01

    Recently, great attention has been paid to in situ gel-forming chitosan/glycerol-phosphate (chitosan/Gp) solution due to their good biodegradability and thermosensitivity. This in situ gel-forming system is injectable fluid that can be introduced into the body in a minimally invasive manner prior to solidifying within the desired tissue. At the present study, insulin release from chitosan/Gp solution has been investigated. Insulin in different concentrations was loaded in two formulations of chitosan/Gp solution and in vitro drug release was studied over a period of 3 weeks. Results indicated that the release of insulin from chitosan/Gp gel decreases by increasing in Gp salt and initial insulin concentration. Stability of released insulin was investigated by 8-anilino-1-naphthalenesulfonate probe. Results proved that insulin have been released in its native form. Because of simple preparation and administration, prolonged release of insulin and stability of released insulin, this in situ gel-forming system could be used as a controlled release delivery system for insulin. PMID:22391886

  10. Electrophoretic deposition of composite hydroxyapatite-chitosan coatings

    SciTech Connect

    Pang Xin [Department of Materials Science and Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4L7 (Canada); Zhitomirsky, Igor [Department of Materials Science and Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4L7 (Canada)]. E-mail: zhitom@mcmaster.ca

    2007-04-15

    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 {mu}m. 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 substrates00.

  11. Chitosan-based nanocoatings for hypothermic storage of living cells.

    PubMed

    Bulwan, Maria; Antosiak-Iwa?ska, Magdalena; Godlewska, Ewa; Granicka, Ludomira; Zapotoczny, Szczepan; Nowakowska, Maria

    2013-11-01

    The formation of ultrathin chitosan-based nanocoating on HL-60 model cells and their protective function in hypothermic storage are presented. HL-60 cells are encapsulated in ultrathin shells by adsorbing cationic and anionic chitosan derivatives in a stepwise, layer-by-layer, procedure carried out in an aqueous medium under mild conditions. The chitosan-based films are also deposited on model lipid bilayer and the interactions are studied using ellipsometry and atomic force microscopy. The cells covered with the chitosan-based films and stored at 4?°C for 24?h express viability comparable to that of the control sample incubated at 37?°C, while the unprotected cells stored under the same conditions do not show viability. It is shown that the chitosan-based shell protects HL-60 cells against damaging effect of hypothermic storage. Such nanocoatings provide protection, mechanical stability, and support the cell membrane, while ensuring penetration of small molecules such as nutrients/gases what is essential for cell viability. PMID:23966342

  12. Chitosan-nanosilica hybrid materials: Preparation and properties

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

    The research focuses on the synthesis of novel organic-inorganic hybrid materials based on polysaccharide chitosan and nanosilicas (SiO2, TiO2/SiO2 and Al2O3/SiO2). 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 SBET 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.

  13. Highly efficient adsorption of chlorophenols onto chemically modified chitosan

    NASA Astrophysics Data System (ADS)

    Zhou, Liang-Chun; Meng, Xiang-Guang; Fu, Jing-Wei; Yang, Yu-Chong; Yang, Peng; Mi, Chun

    2014-02-01

    A novel chemically modified chitosan CS-SA-CD with phenol and ?-cyclodextrin groups was prepared. The adsorptions of phenol, 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), 2,4-dichlorophenol (DCP) and 2,4,6-trichlorophenol (TCP) on the functional chitosan from aqueous solution were investigated. CS-SA-CD exhibited excellent adsorption ability for chlorophenols especially for DCP and TCP. The maximum adsorption capacities of phenol, 2-CP, 4-CP, DCP and TCP on CS-SA-CD were 59.74, 70.52, 96.43, 315.46 and 375.94 mg/g, respectively. The scanning electron microscope and Brunauer-Emmett-Teller analyses revealed that the introduction of phenol group changed the surface morphology and surface properties of chitosan. The modified chitosan CS-SA-CD possesses larger surface areas (4.72 m2/g), pore volume (7.29 × 10-3 mL/g) and average pore diameter (59.99 Å) as compared to those of chitosan 3.27 m2/g, 2.00 × 10-3 mL/g and 15.95 Å, respectively. The enhanced adsorption of chlorophenols was also attributed to the interaction of hydrogen bond between Cl atom and sbnd OH group. The adsorption of chlorophenols on CS-SA-CD followed the pseudo-second-order kinetic model. Adsorbent could be regenerated easily and the regenerated CS-SA-CD remained 80-91% adsorption efficiency.

  14. Incorporation of copper into chitosan scaffolds promotes bone regeneration in rat calvarial defects.

    PubMed

    D'Mello, Sheetal; Elangovan, Satheesh; Hong, Liu; Ross, Ryan D; Sumner, D Rick; Salem, Aliasger K

    2015-07-01

    The objective of this study was to investigate the effects of a copper loaded chitosan scaffold on bone regeneration in critical-sized calvarial defects in rats. Chitosan scaffolds and copper-chitosan scaffolds were fabricated and characterized by scanning electron microscopy (SEM). Chitosan and copper-chitosan scaffolds were implanted into 5 mm diameter critical-sized calvarial defects in Fisher 344 male rats. Empty defects (no scaffolds) were included as a control. After 4 weeks, the rats were sacrificed for microcomputed tomography (micro-CT) and histological analysis of new bone tissue development. Microscopy images revealed the uniformly porous structure of chitosan and copper-chitosan scaffolds. Significant bone regeneration was noted in the defects treated with copper-chitosan scaffolds when evaluated using micro-CT and histological analysis, when compared with other groups tested. On analysis of the micro-CT scans, an eleven-fold and a two-fold increase in the new bone volume/total volume (BV/TV) % was found in defects treated with the copper-chitosan scaffolds, when compared to empty defects and chitosan scaffolds, respectively. This study demonstrated the suitability of copper-crosslinked chitosan scaffolds for bone tissue engineering and provides the first evidence that inclusion of copper ions in scaffolds can enhance tissue regeneration. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 1044-1049, 2015. PMID:25230382

  15. Degradation of chitosan by gamma ray with presence of hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    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.

  16. Improving effects of chitosan nanofiber scaffolds on osteoblast proliferation and maturation

    PubMed Central

    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

  17. Use of Myocardial Matrix in a Chitosan-Based Full-Thickness Heart Patch

    PubMed Central

    Pok, Seokwon; Benavides, Omar M.; Hallal, Patrick

    2014-01-01

    A novel cardiac scaffold comprised of decellularized porcine heart matrix was investigated for use as a biodegradable patch with a potential for surgical reconstruction of the right ventricular outflow tract. Powdered heart matrix solution was blended with chitosan and lyophilized to form three-dimensional scaffolds. For this investigation, we examined the influence of different blending ratios of heart matrix to chitosan on porosity and mechanical properties, then gene expression and electrophysiological function of invading neonatal rat ventricular myocytes (NRVM) compared to type-A gelatin/chitosan composite scaffolds. Heart matrix/chitosan-blended hydrogels (1.6?mg/mL heart matrix) had similar porosity (109±34??m), and elastic modulus (13.2±4.0?kPa) as previously published gelatin/chitosan scaffolds. Heart matrix/chitosan hydrogels maintained>80% viability and had higher NRVM retention (?1000 cells/mm2) than gelatin/chitosan scaffolds. There was a significant increase in ?-myosin heavy chain and connexin-43 expression in NRVM cultured on heart matrix/chitosan scaffolds after 14 days compared with gelatin/chitosan scaffolds. Further, heart matrix/chitosan scaffolds had significantly higher conduction velocity (12.6±4.9?cm/s) and contractile stress (0.79±0.13 mN/mm2) than gelatin/chitosan scaffolds. In summary, NRVM cultured on heart matrix scaffold showed improvements in contractile and electrophysiological function. PMID:24433519

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

    PubMed Central

    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

  19. Chitosan-Copper (II) complex as antibacterial agent: synthesis, characterization and coordinating bond- activity correlation study

    NASA Astrophysics Data System (ADS)

    Mekahlia, S.; Bouzid, B.

    2009-11-01

    The antimicrobial activity of chitosan is unstable and sensitive to many factors such as molecular weight. Recent investigations showed that low molecular weight chitosan exhibited strong bactericidal activities compared to chitosan with high molecular weight. Since chitosan degradation can be caused by the coordinating bond, we attempt to synthesize and characterize the chitosan-Cu (II) complex, and thereafter study the coordinating bond effect on its antibacterial activity against Salmonella enteritidis. Seven chitosan-copper complexes with different copper contents were prepared and characterized by FT-IR, UV-vis, XRD and atomic absorption spectrophotometry (AAS). Results indicated that for chitosan-Cu (II) complexes with molar ratio close to 1:1, the inhibition rate reached 100%.

  20. Metal accumulation in Lolium perenne and Brassica napus as affected by application of chitosans.

    PubMed

    Kamari, A; Pulford, I D; Hargreaves, J S J

    2012-10-01

    The effects of chitosan, a fishery waste-based material, and its derivative glutaraldehyde cross-linked chitosan (chitosan-GLA) on metal uptake by Lolium perenne (perennial ryegrass) and Brassica napus (rapeseed) were studied in a greenhouse pot experiment. Metal uptake by perennial ryegrass was highly dependent on the rate of addition of the chitosans. Low application rate (1% w/w) enhanced metal uptake, whereas 10% (w/w) addition decreased metal uptake. It was estimated that chitosan 1% (w/w) treatment could assist perennial ryegrass to remove approximately 3.2 kg Zn/ha and 0.29 kg Pb/ha. For rapeseed, metal uptake was decreased at all rates of application of chitosans. The ammonium acetate extractable metals in soil decreased following application of chitosans and plant growth. PMID:22908653

  1. In vivo study of chitosan-natural nano hydroxyapatite scaffolds for bone tissue regeneration.

    PubMed

    Lee, Jong Seo; Baek, Sang Dae; Venkatesan, Jayachandran; Bhatnagar, Ira; Chang, Hee Kyung; Kim, Hui Taek; Kim, Se-Kwon

    2014-06-01

    Significant development has been achieved with bioceramics and biopolymer scaffolds in the construction of artificial bone. In the present study, we have developed and compared chitosan-micro hydroxyapatite (chitosan-mHA) and chitosan-nano hydroxyapatite (chitosan-nHA) scaffolds as bone graft substitutes. The biocompatibility and cell proliferation of the prepared scaffolds were checked with preosteoblast (MC3T3-E1) cells. Total Volume (TV), bone volume (BV), bone surface (BS), trabecular thickness (Tb.Th), trabecular number (Tb.N) and trabecular separation (Tb.Sp) were found to be higher in chitosan-nHA than chitosan-mHA scaffold. Hence, we suggest that chitosan-nHA scaffold could be a promising biomaterial for bone tissue engineering. PMID:24705167

  2. Sorption of As(V) from waters using chitosan and chitosan-immobilized sodium silicate prior to atomic spectrometric determination.

    PubMed

    Boyaci, Ezel; Ero?lu, Ahmet E; Shahwan, Talal

    2010-01-15

    A natural biosorbent containing amine functional groups, chitosan, and a novel sorbent, chitosan-immobilized sodium silicate, were prepared and utilized for the selective sorption of As(V) from waters prior to its determination by atomic spectrometric techniques, namely, hydride generation atomic absorption spectrometry (HGAAS) and inductively coupled plasma mass spectrometry (ICP-MS). Chitosan was synthesized from chitin and sodium silicate was used as the immobilization matrix due to its straightforward synthesis. Through sequential sorption studies, it was shown that chitosan-immobilized sodium silicate has exhibited a better chemical stability than the chitosan itself which demonstrates the advantage of immobilization method. Both chitosan and chitosan-immobilized sodium silicate were shown to selectively adsorb As(V), arsenate, from waters at pH 3.0 at which neither chitin nor sodium silicate displayed any sorption towards As(V). The sorption of arsenate by chitosan is supposed to have electrostatic nature since pH of 3.0 is both the point at which the amino groups in chitosan are protonated and also the predominant form of As(V) is H(2)AsO(4)(-). A pre-oxidation step is required if both As(III) and As(V) are to be determined. Desorption from the sorbents was realized with 1.0% (w/v) l-cysteine prepared in a pH 3.0 solution adjusted with HCl. Among the possible interfering species tested, only Te(IV) and Sb(III) were shown to cause a decrease in the sorption capacity especially at high interferant concentrations. High concentrations of Sb(III) also resulted in gas phase interference during hydride generation. The validity of the method was checked both via spike recovery experiments and also through the analysis of a standard reference material. Spike recovery tests were carried out with four different types of water; namely, ultra-pure, bottled drinking, tap, and sea water; and percent recovery values were found to be 114 (+/-4), 112 (+/-2), 43 (+/-4), and 0 (+/-1), respectively. It was concluded that the proposed methodology can be applied efficiently to low-to-medium ionic strength solutions, such as most drinking waters. The accuracy of the method was additionally investigated through the analysis of a standard reference material and a good correlation was found between the determined (26.6+/-2.4microgL(-1)) and the certified (26.67microgL(-1)) value. PMID:20006113

  3. Impact of acidity and metal ion on the antibacterial activity and mechanisms of ?- and ?-chitosan.

    PubMed

    Bingjun, Qian; Jung, Jooyeoun; Zhao, Yanyun

    2015-03-01

    This study investigated the effects of acidity and metal ion on the antibacterial activity of ?- and ?-chitosan at different molecular weights (Mw, 22-360 kDa) against Escherichia coli and Listeria innocua through agar well diffusion assay. Spectrophotometric, electrophoretic, and confocal fluorescence microscopy analysis were further employed to evaluate the antibacterial mechanisms probably involved. Increasing pH from 4.0 to 5.0 weakened the antibacterial ability of chitosan as shown by the decreased bacteria growth inhibition zone (BGIZ) from 0.63 to 0.57 cm for ?-chitosan (61 kDa) and from 0.62 to 0.57 cm for ?-chitosan (30 kDa) against E. coli. All ?- and ?-chitosan samples showed antibacterial activity against L. innocua, in which 22 kDa ?-chitosan and 30 kDa ?-chitosan at pH 4.0 had the highest antibacterial activity with BGIZ of 1.22 and 0.98 cm, respectively. Interactive effect between pH and Mw on the antibacterial activity of ?-chitosan was observed, but not of ?-chitosan. Adding Co(2+) and Ni(2+) significantly improved the antibacterial activity of chitosan, while adding K(+), Na(+), and Li(+) significantly weakened the antibacterial activity of some ?- and ?-chitosan samples (P?chitosan showed different metal ion absorption capacities. Results indicate that chitosan might insert into the groove of bacterial DNA double helix structure to induce DNA degradation and permeate through bacteria cell membranes and combine with genomic DNA to induce its dysfunction, providing evidences for the antibacterial mechanisms of chitosan. PMID:25578156

  4. Mineralization of pristine chitosan film through biomimetic process.

    PubMed

    Baskar, D; Balu, Rajkamal; Kumar, T S Sampath

    2011-10-01

    The biomineralization of pristine chitosan film without any prior surface treatment was evaluated by immersing the film in simulated body fluid (SBF) at 37°C for 3 weeks. The film was prepared by solvent casting method using chitosan of known degree of deacetylation (DD). The formation of the hydroxyapatite (HA) phase on the film surface after immersion was studied periodically by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), energy dispersive X-ray analysis (EDX) and scanning electron microscopy (SEM) methods. The electron micrographs showed the morphology of the deposited apatite as small globules appearing uniformly throughout the films surfaces. The Ca/P ratio of the apatite was found to increase with increase in immersion time and approaching towards the stoichiometric value of the HA phase. The mineralized chitosan film could be of promising support to hard tissue regeneration. PMID:21641923

  5. Chitosan based edible films and coatings: a review.

    PubMed

    Elsabee, Maher Z; Abdou, Entsar S

    2013-05-01

    Chitosan is a biodegradable biocompatible polymer derived from natural renewable resources with numerous applications in various fields, and one of which is the area of edible films and coatings. Chitosan has antibacterial and antifungal properties which qualify it for food protection, however, its weak mechanical properties, gas and water vapor permeability limit its uses. This review discusses the application of chitosan and its blends with other natural polymers such as starch and other ingredients for example essential oils, and clay in the field of edible films for food protection. The mechanical behavior and the gas and water vapor permeability of the films are also discussed. References dealing with the antimicrobial behavior of these films and their impact on food protection are explored. PMID:23498203

  6. Chitosan-alginate nanocapsules for encapsulation of turmeric oil.

    PubMed

    Lertsutthiwong, P; Rojsitthisak, P

    2011-12-01

    Turmeric oil is widely used in pharmaceutical and cosmetic applications because of its antibacterial, antifungal, antioxidant, and insect-repellent properties. However, turmeric oil is volatile, insoluble in water and unstable in certain environments, which causes difficulties with formulation development and stability of new products. One approach to overcome these problems is to encapsulate turmeric oil in carriers formed from naturally occurring polysaccharides. Among such polysaccharides, chitosan and alginate have been widely used as particulate carriers for encapsulation and controlled release of bioactive compounds. The potential for size reduction of the carriers to the nanometer scale is of particular interest for delivery systems. In this review, we provide an overview of the versatile properties of turmeric oil and discuss the use of alginate and chitosan for capsule formation and encapsulation of turmeric oil in chitosan-alginate nanocapsules. We also discuss the in vitro skin permeation of turmeric oil from nanocapsules. PMID:22312692

  7. Superhydrophobic chitosan-based coatings for textile processing

    NASA Astrophysics Data System (ADS)

    Ivanova, N. A.; Philipchenko, A. B.

    2012-12-01

    A simple method to design the superhydrophobic anti-bacterial textile for biomedical applications was developed. For the coating formulation the spraying of nanoparticles dispersion over the textile sample was applied, allowing the way to get multiscale textured layer on a top of cotton fabric. The anti-bacterial functionality of coating is supported by using chitosan-based nanoparticles. In our approach the fabrication of nanoparticles was based on electrostatic interaction between amine group of chitosan and negatively charged fluoroanion. It was demonstrated that the relative number of fluoroanions per elementary unit of chitosan plays the crucial role in the structure of aggregates in the coating and its wettability as well as in durability of coatings in contact with aqueous media.

  8. Study of polyelectrolyte complexes of chitosan and sulfoethyl cellulose

    SciTech Connect

    Baklagina, Yu. G., E-mail: membrane@hq.macro.ru; Kononova, S. V.; Petrova, V. A.; Kruchinina, E. V.; Nud'ga, L. A. [Russian Academy of Sciences, Institute of Macromolecular Compounds (Russian Federation)] [Russian Academy of Sciences, Institute of Macromolecular Compounds (Russian Federation); Romanov, D. P. [Russian Academy of Sciences, Grebenshchikov Institute of Silicate Chemistry (Russian Federation)] [Russian Academy of Sciences, Grebenshchikov Institute of Silicate Chemistry (Russian Federation); Klechkovskaya, V. V.; Orekhov, A. S. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)] [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Bogomazov, A. V.; Arkhipov, S. N. [ZAO Nauchnye Pribory (Russian Federation)] [ZAO Nauchnye Pribory (Russian Federation)

    2013-03-15

    The complexing of polycation chitosan and polyanion sulphoethyl cellulose during the formation of polyelectrolyte simplex membranes using the layer-by-layer deposition of a solution of one polyion on a gel-like film of another one has been studied. The structural characteristics of the multilayer composites and their components have been analyzed by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray microanalysis. A technique is proposed for studying the structure of surface layers of thin polymer films (15-20 {mu}m) using a portable DIFREI-401 diffractometer. It is shown that the sequence of layer deposition during the formation of membrane films does not affect their structural characteristics. The interaction between positively charged chitosan groups (-NH{sub 3}{sup +}) and negatively charged sulfoethyl cellulose groups (-SO{sub 3}{sup -}) during the growth of polyelectrolyte complexes results in a packing of chitosan chains in the multilayer film.

  9. N-halamine-based chitosan: preparation, characterization, and antimicrobial function.

    PubMed

    Cao, Zhengbing; Sun, Yuyu

    2008-04-01

    Upon chlorine bleach treatment, amino groups in chitosan were transformed into N-halamine structures. The transformation was confirmed by UV/VIS, XPS, DSC, and TGA evaluation and iodimetric titration. The N-halalmine-based chitosan provided total kill of 10(8)-10(9) colony forming units (CFU/mL) of E. coli (gram-negative bacteria) and S. aureus (gram-positive bacteria) in 10 and 60 min, respectively. SEM observations demonstrated that the chlorinated chitosan effectively prevented the formation of bacterial biofilms. The antimicrobial activity and bio film controlling function were stable for longer than 1 month; when the functions were lost due to extensive use and/or prolonged storage, they could be readily recharged by another bleach treatment. The antimicrobial mechanism was also discussed. PMID:17688258

  10. Desulfurization of gasoline using molecularly imprinted chitosan as selective adsorbents.

    PubMed

    Chang, Yonghui; Zhang, Lei; Ying, Hanjie; Li, Zhenjiang; Lv, Hao; Ouyang, Pingkai

    2010-01-01

    For desulfurization of gasoline, novel chitosan-based molecularly imprinted polymer (MIP) was prepared by cross-linking chitosan with epichlorohydrin in the presence of dibenzothiophene (DBT) as the template. The influence of cross-linking ratio on the specific adsorption was evaluated. The effects of the types and the amounts of porogen on selectivity of the chitosan MIP were also examined. Results showed that MIP has a higher recognition property to DBT. The maximum rebinding capacities of the MIP reached 22.69 mg g(-1) in the model solution. The adsorption behaviors of the MIP including adsorption kinetics, isotherms, and thermodynamic parameters were investigated and the experimental data agreed well with the Langmuir model. The dynamical adsorption behaved in first-order kinetics. Negative values for the Gibbs free energy showed that the adsorptions were spontaneous processes. The MIP was further used to selectively adsorb organosulfur from gasoline. PMID:19050832

  11. Preparation of acetylsalicylic acid-acylated chitosan as a novel polymeric drug for drug controlled release.

    PubMed

    Liu, Changkun; Wu, Yiguang; Zhao, Liyan; Huang, Xinzheng

    2015-07-01

    The acetylsalicylic acid-acylated chitosan (ASACTS) with high degree of substitution (DS) was successfully synthesized, and characterized with FTIR, (1)H NMR and elemental analysis methods. The optimum synthesis conditions were obtained which gave the highest DS (about 60%) for ASACTS. Its drug release experiments were carried out in simulated gastric and intestine fluids. The results show that the drugs in the form of acetylsalicylic acid (ASA) and salicylic acid (SA) were released in a controlled manner from ASACTS only in simulated gastric fluid. The release profile can be best fitted with logistic and Weibull model. The research results reveal that ASACTS can be a potential polymeric drug for the controlled release of ASA and SA in the targeted gastric environment. PMID:25849997

  12. Preparation of curcumin-loaded pluronic F127/chitosan nanoparticles for cancer therapy

    NASA Astrophysics Data System (ADS)

    Phuc Le, Thi Minh; Phuc Pham, Van; Lua Dang, Thi Minh; Huyen La, Thi; Hanh Le, Thi; Huan Le, Quang

    2013-06-01

    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.

  13. Injectable thermosensitive hydrogel based on chitosan and quaternized chitosan and the biomedical properties.

    PubMed

    Ji, Qiu Xia; Chen, Xi Guang; Zhao, Qing Sheng; Liu, Cheng Sheng; Cheng, Xiao Jie; Wang, Ling Chong

    2009-08-01

    A novel injectable thermosensitive hydrogel (CS-HTCC/alpha beta-GP) was successfully designed and prepared using chitosan (CS), quaternized chitosan (HTCC) and alpha,beta-glycerophosphate (alpha,beta-GP) without any additional chemical stimulus. The gelation point of CS-HTCC/alpha beta-GP can be set at a temperature close to normal body temperature or other temperature above 25 degrees C. The transition process can be controlled by adjusting the weight ratio of CS to HTCC, or different final concentration of alpha,beta-GP. The optimum formulation is (CS + HTCC) (2% w/v), CS/HTCC (5/1 w/w) and alpha,beta-GP 8.33% or 9.09% (w/v), where the sol-gel transition time was 3 min at 37 degrees C. The drug released over 3 h from the CS-HTCC/alpha,beta-GP thermosensitive hydrogel in artificial saliva pH 6.8. In addition, CS-HTCC/alpha,beta-GP thermosensitive hydrogel exhibited stronger antibacterial activity towards two periodontal pathogens (Porphyromonas gingivalis, P.g and Prevotella intermedia, P.i). CS-HTCC/alpha, beta-GP thermosensitive hydrogel was a considerable candidate as a local drug delivery system for periodontal treatment. PMID:19322644

  14. Synthesis Of Graphene/Chitosan Nanocomposite Thin Films

    NASA Astrophysics Data System (ADS)

    Ganesh, S.; Arockiadoss; Ramaprabhu, S.

    2010-10-01

    In this paper, we propose a cost-efficient thin film synthesis of the nanocomposite of Graphene and Chitosan using solution casting technique. Characterizations of the thin films clearly indicate the presence of dispersed flakes of Graphene in Chitosan. Spectroscopic studies reveal the presence of nanoparticles of Carbon in the composite though they also indicate presence of Oxygen which transcend from the bulk Graphite crystals. Preliminary amperometric studies reveal an increase in current with absorption of moisture and a potential humidity sensing ability of the nanocomposite thin film.

  15. Irradiated PVAl membrane swelled with chitosan solution as dermal equivalent

    NASA Astrophysics Data System (ADS)

    Rodas, A. C. D.; Ohnuki, T.; Mathor, M. B.; Lugao, A. B.

    2005-07-01

    Synthetic membranes as dermal equivalent can be applied at in vitro studies for developing new transdermal drugs or cosmetics. These membranes could be composed to mimic the dermis and seed cultivated keratinocytes as epidermal layer on it. The endothelial cells ingrowth to promote neovascularization and fibroblasts ingrowth to promote the substitution of this scaffold by natural components of the dermis. As, they can mimic the scaffold function of dermis; the membranes with biological interaction could be used for in vivo studies as dermal equivalent. For this application, poly(vinyl alcohol) (PVAl) membranes crosslinked by gamma radiation were swelled with chitosan solution. PVAl do not interact with the organism when implanted and is intended to mimic the mechanical characteristics of the dermal scaffold. The chitosan as a biocompatible biosynthetic polysaccharide were incorporated into PVAl membranes to improve the organism response. Degradation of chitosan by the organism occurs preferably by hydrolysis or enzymatic action, for example, by lysozyme. For this purpose the swelling kinetic of PVAl membranes with chitosan solution were performed and it was verified their degradation in vitro. The results showed that the swelling equilibrium of the PVAl membranes with chitosan membranes was reached in 120 h with average swelling of 1730%. After swelling, PVAl and chitosan/PVAl membranes were dried and immersed in phosphate buffer solution pH 5.7 and pH 7.4, with and without lysozyme, as those pH values are the specific physiologic pH for external skin and the general physiological pH for the organism, respectively. It was verified that the pure PVAl membrane did not showed change in their mass during 14 days. PVAl membranes swelled with chitosan solution showed mass decrease from 1 to 14 days inside these solutions. The highest mass decrease was verified at pH 5.7 in phosphate buffer solution without lysozyme. The smallest mass decrease was verified at pH 7.4 in phosphate buffer solution without lysozyme. In general, PVAl membranes swelled with chitosan solution showed a clear mass decrease at pH 5.7.

  16. Chitosan as an adjuvant for a Helicobacter pylori therapeutic vaccine.

    PubMed

    Gong, Yanfeng; Tao, Liming; Wang, Fucai; Liu, Wei; Jing, Lei; Liu, Dongsheng; Hu, Sijun; Xie, Yong; Zhou, Nanjin

    2015-09-01

    The aim of the present study was to delineate the therapeutic effect of a Helicobacter pylori vaccine with chitosan as an adjuvant, as well as to identify the potential mechanism against H. pylori infection when compared with an H. pylori vaccine, with cholera toxin (CT) as an adjuvant. Mice were first infected with H. pylori and, following the establishment of an effective infection model, were vaccinated using an H. pylori protein vaccine with chitosan as an adjuvant. Levels of H. pylori colonization, H. pylori?specific antibodies and cytokines were determined by enzyme?linked immunosorbent assay. The TLR4 and Foxp3 mRNA and protein levels were determined by reverse transcription polymerase chain reaction and immunohistochemistry, respectively. It was identified that the H. pylori elimination rate of the therapeutic vaccine with chitosan as an adjuvant (58.33%) was greater than the therapeutic vaccine with CT as an adjuvant (45.45%). The therapeutic H. pylori vaccine with chitosan as an adjuvant induced significantly greater antibody and cytokine levels when compared with the control groups. Notably, the IL?10 and IL?4 levels in the groups with chitosan as an adjuvant to the H. pylori vaccine were significantly greater than those in the groups with CT as an adjuvant. The mRNA expression levels of TLR4 and Foxp3 were significantly elevated in the mice that were vaccinated with chitosan as an adjuvant to the H. pylori vaccine, particularly in mice where the H. pylori infection had been eradicated. The H. pylori vaccine with chitosan as an adjuvant effectively increased the H. pylori elimination rate, the humoral immune response and the Th1/Th2 cell immune reaction; in addition, the therapeutic H. pylori vaccine regulated the Th1 and Th2 response. The significantly increased TLR4 expression and decreased CD4+CD25+Foxp3+Treg cell number contributed to the immune clearance of the H. pylori infection. Thus, the present findings demonstrate that in mice the H. pylori vaccine with chitosan as an adjuvant exerts an equivalent immunotherapeutic effect on H. pylori infection when compared with the H. pylori vaccine with CT as an adjuvant. PMID:26095723

  17. Optimized synthesis of glycyrrhetinic acid-modified chitosan 5-fluorouracil nanoparticles and their characteristics

    PubMed Central

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

    2014-01-01

    The nanoparticle drug delivery system, which uses natural or synthetic polymeric material as a carrier to deliver drugs to targeted tissues, has a broad prospect for clinical application for its targeting, slow-release, and biodegradable properties. Here, we used chitosan (CTS) and hepatoma cell-specific binding molecule glycyrrhetinic acid to synthesize glycyrrhetinic acid-modified chitosan (GA-CTS). The synthetic product was confirmed by infrared (IR) spectra and hydrogen-1 nuclear magnetic resonance. The GA-CTS/5-fluorouracil (5-FU) nanoparticles were synthesized by combining GA-CTS and 5-FU and conjugating 5-FU onto the GA-CTS nanomaterial. The central composite design was performed to optimize the preparation process as CTS:tripolyphosphate sodium (TPP) weight ratio =5:1, 5-FU:CTS weight ratio =1:1, TPP concentration =0.05% (w/v), and cross-link time =50 minutes. GA-CTS/5-FU nanoparticles had a mean particle size of 193.7 nm, a polydispersity index of 0.003, a zeta potential of +27.4 mV, and a drug loading of 1.56%. The GA-CTS/5-FU nanoparticle had a protective effect on the drug against plasma degrading enzyme, and provided a sustained release system comprising three distinct phases of quick, steady, and slow release. Our study showed that the peak time, half-life time, mean residence time and area under the curve of GA-CTS/5-FU were longer or more than those of the 5-FU group, but the maximum concentration (Cmax) was lower. We demonstrated that the nanoparticles accumulated in the liver and have significantly inhibited tumor growth in an orthotropic liver cancer mouse model. PMID:24493926

  18. Alginate and chitosan functionalization for micronutrient encapsulation.

    PubMed

    Han, Jaejoon; Guenier, Anne-Sophie; Salmieri, Stéphane; Lacroix, Monique

    2008-04-01

    A new method for encapsulation of micronutrients was successfully developed. The encapsulation matrix consisted of two polymers (alginate and chitosan), which were functionalized by acylation with palmitoyl chloride. The structural modifications of polymers were confirmed by Fourier transform infrared (FTIR) spectroscopy. Beads were formed by ionic gelation, and their mechanical and physical characteristics (puncture strength and deformation, viscoelasticity, water vapor permeability, and rate of gel swelling) were evaluated using beads or films made of bead-forming solutions. Functionalization increased elasticity and water impermeability of polymer films. Stability of selected encapsulated micronutrients (ferrous fumarate, ascorbic acid, and beta-carotene) was also evaluated under two levels of temperature (23 and 45 degrees C) and relative humidity (56 and 100%) for 6 months. Encapsulation strongly increased the stability of micronutrients. No difference was observed in the encapsulated micronutrients' stability between nonfunctionalized and functionalized beads. Finally, a release study in gastrointestinal media was conducted. Results showed that beads were not susceptible to enzymatic and acidic attacks during stomach transit. This research demonstrates the potential of a new encapsulation method to protect bioactive molecules from temperature, moisture, and acidic conditions. PMID:18324770

  19. Photodynamic therapy using glycol chitosan grafted fullerenes.

    PubMed

    Kwag, Dong Sup; Oh, Nam Muk; Oh, Young Taik; Oh, Kyung Taek; Youn, Yu Seok; Lee, Eun Seong

    2012-07-15

    Glycol chitosan (GC)-grafted fullerene (GC-g-C(60)) conjugates were developed for use in photodynamic therapy of tumor cells. GC-g-C(60) was synthesized in anhydrous benzene/dimethylsulfoxide (DMSO) co-solvent via the chemical conjugation of free amine groups of GC to CC double bonds of C(60). The GC-g-C(60) with 5×10(-4) C(60) molecules per one repeating unit of GC was soluble in water. As C(60) molecules conjugated to GC increased to 0.16 molecules per one repeating unit of GC, GC-g-C(60) started to form supramolecular assemblies (?30 nm) stabilized in phosphate buffer saline (PBS, 150 mM, pH 7.4). Upon 670 nm light illumination, photo-responsive properties of GC-g-C(60) allowed tremendous singlet oxygen generation in tumor cells for super phototoxicity. GC-g-C(60) also showed highly increased tumor accumulation ability for in vivo tumor of KB tumor-bearing nude mice. It is expected that our GC-g-C(60) conjugate may be a good candidate for in vivo photodynamic therapy in various malignant tumor cells. PMID:22537808

  20. Dual catalysis with magnetic chitosan: direct synthesis of cyclic carbonates from olefins with carbon dioxide using isobutyraldehyde as the sacrificial reductant.

    PubMed

    Kumar, Subodh; Singhal, Nikita; Singh, Raj K; Gupta, Piyush; Singh, Raghuvir; Jain, Suman L

    2015-07-14

    Chitosan coated magnetic nanoparticles were synthesized and used as a support for the immobilization of the cobalt(ii) acetylacetonate complex [Co(acac)2] and quaternary triphenylphosphonium bromide [P(+)Ph3Br(-)] targeting -NH2 and -OH moieties located on the surface of chitosan. The synthesized material was used as a catalyst for one pot direct synthesis of cyclic carbonates from olefins via an oxidative carboxylation approach with carbon dioxide using isobutyraldehyde as the sacrificial reductant and molecular oxygen as the oxidant. After the reaction, the catalyst was recovered by applying an external magnet and reused for several runs without significant loss in catalytic activity and no leaching was observed during this course. PMID:26055991

  1. Synthesis and characterization of a novel chitosan-N-acetyl-homocysteine thiolactone polymer using MES buffer.

    PubMed

    Ferris, C; Casas, M; Lucero, M J; de Paz, M V; Jiménez-Castellanos, M R

    2014-10-13

    We report a new "green" approach to synthesize a novel thiolated chitosan conjugate, chitosan-N-acetyl-homocysteine thiolactone (chitosan-AcHcys) using a "Good's buffers", 2-(N-morpholino)ethanesulfonic acid (MES). After that, the crosslinked Xr-chitosan-AcHcys was obtained only in the presence of air, without other reactants. The chitosan-AcHcys spectrum shows a partial incorporation of the thiolactone onto the polymer backbone. The derivative thermogravimetric analysis confirmed that chitosan-AcHcys is slightly less stable than starting chitosan; however, the peak profile is broadened which is indicative of deeper changes in the thermal degradation process. Also, aqueous dispersions with different concentrations of the crosslinked material (Xr-chitosan-AcHcys) were prepared and rheologically characterized. All aqueous dispersions are viscoelastic fluid with shear-thinning behavior. The viscosity of the dispersions (1-7% of chitosan-AcHcys) increases as a function of polymer concentration. So, we have achieved to disperse a high concentration of thiolated-chitosan derivative in water with different rheological characteristics, which could affect the drug release. PMID:25037337

  2. Reduction of thrombogenicity of PVC-based sodium selective membrane electrodes using heparin-modified chitosan.

    PubMed

    Badr, Ibrahim H A; Gouda, M; Abdel-Sattar, R; Sayour, Hossam E M

    2014-01-01

    Heparin-modified chitosan (H-chitosan) membrane was utilized to enhance biocompatibility of sodium selective membrane electrode based on the highly thrombogenic polyvinyl chloride (PVC). Sodium ion sensing film was prepared using PVC, sodium ionophore-X, potassium tetrakis(chlorophenyl)-borate, and o-nitrophenyloctylether. The PVC-based sensing film was sandwiched to chitosan or H-chitosan to prevent platelet adhesion on the surface of PVC. Potentiometric response characteristics of PVC-chitosan and PVC-H-chitosan membrane electrodes were found to be comparable to that of a control PVC based sodium-selective electrode. This indicates that chitosan and H-chitosan layers do not alter the response behaviour of the PVC-based sensing film. Biocompatibility of H-chitosan was confirmed by in vitro platelet adhesion study. The platelet adhesion investigations indicated that H-chitosan film is less thrombogenic compared to PVC, which could result in enhancement of biocompatibility of sodium selective membrane electrodes based on PVC, while maintaining the overall electrochemical performance of the PVC-based sensing film. PMID:24274570

  3. Fabrication and Characteristics of Chitosan Sponge as a Tissue Engineering Scaffold

    PubMed Central

    Yamamoto, Kouhei; Ishizaki, Hidetaka; Yoshizawa, Yuu; Yanagiguchi, Kajiro

    2014-01-01

    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??m. 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. PMID:24804246

  4. Emulsion Electrospinning as an Approach to Fabricate PLGA/Chitosan Nanofibers for Biomedical Applications

    PubMed Central

    Tavanai, Hossein; Hilborn, Jöns; Donzel-Gargand, Olivier; Leifer, Klaus; Arpanaei, Ayyoob

    2014-01-01

    Novel nanofibers from blends of polylactic-co-glycolic acid (PLGA) and chitosan have been produced through an emulsion electrospinning process. The spinning solution employed polyvinyl alcohol (PVA) as the emulsifier. PVA was extracted from the electrospun nanofibers, resulting in a final scaffold consisting of a blend of PLGA and chitosan. The fraction of chitosan in the final electrospun mat was adjusted from 0 to 33%. Analyses by scanning and transmission electron microscopy show uniform nanofibers with homogenous distribution of PLGA and chitosan in their cross section. Infrared spectroscopy verifies that electrospun mats contain both PLGA and chitosan. Moreover, contact angle measurements show that the electrospun PLGA/chitosan mats are more hydrophilic than electrospun mats of pure PLGA. Tensile strengths of 4.94?MPa and 4.21?MPa for PLGA/chitosan in dry and wet conditions, respectively, illustrate that the polyblend mats of PLGA/chitosan are strong enough for many biomedical applications. Cell culture studies suggest that PLGA/chitosan nanofibers promote fibroblast attachment and proliferation compared to PLGA membranes. It can be assumed that the nanofibrous composite scaffold of PLGA/chitosan could be potentially used for skin tissue reconstruction. PMID:24689041

  5. A study on antifungal activity of water-soluble chitosan against Macrophomina phaseolina.

    PubMed

    Chatterjee, Sudipta; Chatterjee, Bishnu P; Guha, Arun K

    2014-06-01

    The objective of this study was to evaluate antifungal effect of water-soluble chitosan (s-chitosan) on Macrophomina phaseolina (M. phaseolina) causing jute seedling infection and monitor the change in activity of released enzymes during infection. The minimum inhibitory concentration (MIC) of s-chitosan for M. phaseolina was found at 12.5g/l and s-chitosan exhibited fungistatic mode of action against this pathogen. The application of s-chitosan (12.5g/l) during infection of jute seedlings by M. phaseolina inhibited fungal infection and length of the seedlings was found almost similar to seedlings without infection. M. phaseolina infected jute seedlings showed length of 22mm over 10 days of incubation and it increased to 58mm in presence of s-chitosan (12.5g/l) during incubation for 10 days. TEM study indicated presence of hyphae in the cortical and epidermal cells of fungus infected jute seedlings indicating colonization by the fungus and it disappeared after treatment with s-chitosan. The changes in enzyme profiles of jute seedling during prevention of fungal infection using s-chitosan helped in proper understanding of mode of action of s-chitosan as antifungal agent. The activity of defense related enzymes like chitosanase and peroxidase in infected seedlings was observed to be enhanced after treatment with s-chitosan. PMID:24747381

  6. Utilization of chitosan as an antimicrobial agent for pasteurized palm sap (Borassus flabellifer Linn.) during storage.

    PubMed

    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. PMID:25694681

  7. Effect of chitosan molecular weight on the functional properties of chitosan-maltose Maillard reaction products and their application to fresh-cut Typha latifolia L.

    PubMed

    Li, Song-Lin; Lin, Jing; Chen, Xiao-Ming

    2014-02-15

    The objective was to evaluate antimicrobial, antioxidant and copper-chelating activities of Maillard reaction products (MRP) prepared from maltose and different molecular weight chitosan, and their effects on preservation of fresh-cut Typha latifolia L. (TLL). LMRP (maltose and low molecular weight chitosan MRP) showed the highest browning and UV absorbance as well as fluorescence intensity. The DPPH radical scavenging activity, reducing power and copper-chelating activity of chitosan-maltose MRP varied depending on the chitosan molecular weight. HMRP (maltose-high molecular weight chitosan MRP) exhibited better effects on inhibiting PPO activity and discoloration, alleviating declines of total soluble solids and ascorbic acid content of fresh-cut TLL. LMRP and MMRP (maltose-medium molecular weight chitosan MRP) effectively decreased weight loss and maintained firmness of TLL, respectively. These results indicated that molecular weight of chitosan had a great impact on the functional properties of chitosan-maltose MRP and their application to be used as a preservative. PMID:24507336

  8. Chitosan and its antimicrobial potential – a critical literature survey

    PubMed Central

    Raafat, Dina; Sahl, Hans?Georg

    2009-01-01

    Summary Chitosan, an aminopolysaccharide biopolymer, has a unique chemical structure as a linear polycation with a high charge density, reactive hydroxyl and amino groups as well as extensive hydrogen bonding. It displays excellent biocompatibility, physical stability and processability. The term ‘chitosan’ describes a heterogenous group of polymers combining a group of physicochemical and biological characteristics, which allow for a wide scope of applications that are both fascinating and as yet uncharted. The increased awareness of the potentials and industrial value of this biopolymer lead to its utilization in many applications of technical interest, and increasingly in the biomedical arena. Although not primarily used as an antimicrobial agent, its utility as an ingredient in both food and pharmaceutical formulations lately gained more interest, when a scientific understanding of at least some of the pharmacological activities of this versatile carbohydrate began to evolve. However, understanding the various factors that affect its antimicrobial activity has become a key issue for a better usage and a more efficient optimization of chitosan formulations. Moreover, the use of chitosan in antimicrobial systems should be based on sufficient knowledge of the complex mechanisms of its antimicrobial mode of action, which in turn would help to arrive at an appreciation of its entire antimicrobial potential. PMID:21261913

  9. Formulation and evaluation of chitosan solid lipid nanoparticles of carbamazepine

    PubMed Central

    2012-01-01

    The present work aims at preparing aqueous suspension of Solid lipid Nanoparticles containing Chitosan (CT) which is a biopolymer that exhibits a number of interesting properties which include controlled drug delivery. Carbamezapine (CBZ) is a lipophilic drug which shows it antiepileptic activity by inactivating sodium channels. The solid lipid Nanoparticles (SLN) of Chitosan-CBZ were prepared by using solvent injection method using ethanol as organic solvent. The prepared SLN formulations exhibited high encapsulation efficiency, high physical stability. The drug incorporated SLNs have demonstrated that the controlled release patterns of the drug for prolonged period. The prepared SLNs were characterized for surface morphology by SEM analysis, entrapment efficiency, zeta potential, FTIR, DSC and In-vitro diffusion studies. The hydrodynamic mean diameter and zeta potential were 168.7 ±1.8?nm and ?28.9 ±2.0?mV for SLN-chitosan-CBZ respectively. Therefore chitosan-SLN can be good candidates to encapsulate CBZ and to increase its therapeutic efficacy in the treatment of Epilepsy. PMID:22695222

  10. Recent Advances in Drugs and Prodrugs Design of Chitosan

    Microsoft Academic Search

    J. Vinsova; E. Vavrikova

    The aim of this review is to outline the recent advances in chitosan molecular modeling, especially its usage as a prodrug or drug in a field of antibacterial, anticarcinogenic and antioxidant activity. Polymeric materials like peptides, polysaccharides and other natural products have recently attracted attention as biodegradabile drug car- riers. They can optimize clinical drug application, minimize the undesirable drug

  11. Electrospun chitosan-based nanofibers and their cellular compatibility.

    PubMed

    Bhattarai, Narayan; Edmondson, Dennis; Veiseh, Omid; Matsen, Frederick A; Zhang, Miqin

    2005-11-01

    Chitosan-based nanofibers with an average fiber diameter controllable from a few microns down to approximately 40 nm and a narrow size distribution were fabricated by electrospinning solutions containing chitosan, polyethylene oxide (PEO), and Triton X-100. Rheological study showed a strong dependence of spinnability and fiber morphology on solution viscosity and thus on chitosan-to-PEO ratio. The nanofibers can be deposited either as a nonwoven mat or as a highly aligned bundle of controllable size. Potential use of this nanofibrous matrix for tissue engineering was studied by examining its integrity in water and cellular compatibility. It was found that the matrix with a chitosan/PEO ratio of 90/10 retained excellent integrity of the fibrous structure in water. Experimental results from cell stain assay and SEM imaging showed that the nanofibrous structure promoted the attachment of human osteoblasts and chondrocytes and maintained characteristic cell morphology and viability throughout the period of study. This nanofibrous matrix is of particular interest in tissue engineering for controlled drug release and tissue remodeling. PMID:15885770

  12. Influence of grape pomace extract incorporation on chitosan films properties.

    PubMed

    Ferreira, Andreia S; Nunes, Cláudia; Castro, Alichandra; Ferreira, Paula; Coimbra, Manuel A

    2014-11-26

    Chitosan has been studied as a renewable polymer to form edible films allowing the incorporation of functional compounds. The aim of this work was to evaluate the effects in the chitosan films properties of the incorporation of grape pomace extracts: 0.15% of hot water extract (mainly polysaccharides), 0.15 and 0.3% of chloroform extract (wax), and 0.3 and 0.75% of n-hexane extract (oil). The evaluation of the surface morphology revealed that the films with the aqueous extract had the most homogeneous and smoother topography. The incorporation of higher proportion of wax and oil led to changes in mechanical properties of the films, namely lower resistance and stiffness. The chitosan-based films with 0.75% oil demonstrated a 75% decrease of solubility in water, due to their hydrophobicity, as confirmed by the contact angle and surface free energy measurements. The hydrophobic films showed higher antioxidant capacity in organic medium (ABTS and DPPH assays) whereas the most hydrophilic films showed an improvement in FRAP and reducing power assays. Therefore, all the chitosan-based films prepared by incorporation of these grape pomace extracts are promising for food shelf life extension. PMID:25256511

  13. Enhancement of acute tendon repair using chitosan matrix.

    PubMed

    Melamed, Eitan; Beutel, Bryan G; Robinson, Dror

    2015-05-01

    Structural failure of rotator cuff repairs has been attributed to multiple factors, including poor repair tissue quality and poor tendon-bone integration. Chitosan gel has been shown to facilitate scarless healing of soft tissues. In the study reported here, we hypothesized that use of a chitosan gel would improve the morphologic appearance of acute rotator cuff repair in a rat model after 12 weeks. Forty Wistar rats were used. In each case, bilateral tenotomy of the supraspinatus tendon was performed, followed by acute repair with sutures. The left shoulder served as a suture-only control, and the right shoulder was augmented with a chitosan gel applied between the ends of the tendon. Histologic analyses were performed to determine the functional and anatomical characteristics of the repair immediately after the operation and 3 days and 1, 2, 4, 6, 8, and 12 weeks after surgery. In the gel-augmented specimens, number of fibroblasts and amount of repair tissue were increased. Compared with the controls, these specimens showed minimal evidence of monocytic infiltration or inflammatory response around the matrix. Structural properties of the augmented shoulder, including pennation angles and fatty atrophy, were significantly improved. These study results showed that use of a chitosan matrix can enhance biological repair of rotator cuff tendons in a rat model. PMID:25950535

  14. Abatement of Azo Dye from Wastewater Using Bimetal-Chitosan

    PubMed Central

    Asgari, Ghorban; Farjadfard, Sima

    2013-01-01

    We introduce a new adsorbent, bimetallic chitosan particle (BCP) that is successfully synthesized and applied to remove the orange II dye from wastewater. The effects of pH, BCP quantity, and contact time are initially verified on the basis of the percentage of orange II removed from the wastewater. Experimental data reveal that the Cu/Mg bimetal and chitosan have a synergistic effect on the adsorption process of the adsorbate, where the dye adsorption by Cu/Mg bimetal, chitosan alone, and bimetal-chitosan is 10, 49, and 99.5%, respectively. The time required for the complete decolorization of orange II by 1?mg/L of BCP is 10?min. The Langmuir model is the best fit for the experimental data, which attains a maximum adsorption capacity of 384.6?mg/g. The consideration of the kinetic behavior indicates that the adsorption of orange II onto the BCP fits best with the pseudo-second-order and Elovich models. Further, the simulated azo dye wastewater can be effectively treated using a relatively low quantity of the adsorbent, 1?mg/L, within a short reaction time of 20?min. Overall, the use of BCP can be considered a promising method for eliminating the azo dye from wastewater effectively. PMID:24348163

  15. Chitosan as template for the synthesis of ceria nanoparticles

    SciTech Connect

    Sifontes, A.B., E-mail: asifonte@ivic.gob.ve [Centro de Quimica, Instituto Venezolano de Investigaciones Cientificas, Caracas 1020-A (Venezuela, Bolivarian Republic of); Gonzalez, G.; Ochoa, J.L. [Centro de Ingenieria, Instituto Venezolano de Investigaciones Cientificas, Caracas 1020-A (Venezuela, Bolivarian Republic of)] [Centro de Ingenieria, Instituto Venezolano de Investigaciones Cientificas, Caracas 1020-A (Venezuela, Bolivarian Republic of); Tovar, L.M.; Zoltan, T. [Centro de Quimica, Instituto Venezolano de Investigaciones Cientificas, Caracas 1020-A (Venezuela, Bolivarian Republic of)] [Centro de Quimica, Instituto Venezolano de Investigaciones Cientificas, Caracas 1020-A (Venezuela, Bolivarian Republic of); Canizales, E. [PDVSA, Intevep, Caracas 1020-A (Venezuela, Bolivarian Republic of)] [PDVSA, Intevep, Caracas 1020-A (Venezuela, Bolivarian Republic of)

    2011-11-15

    Graphical abstract: Cerium oxide nanoparticles with cubic fluorite structure were prepared using chitosan as template, cerium nitrate as a starting material and sodium hydroxide as a precipitating agent. Calcinated powders at 350 {sup o}C contain agglomerated particles with average particle size of {approx}4 nm, very high porosity and foam-like morphology formed by open and close pores. Highlights: {yields} Pure CeO{sub 2} nanoparticles can take place using chitosan as template. {yields} A porous material was obtained. {yields} Blueshifts in the ultraviolet absorption spectra have been observed in cerium oxide nanocrystallites. -- Abstract: Cerium oxide (CeO{sub 2}), nanoparticles were prepared using chitosan as template, cerium nitrate as a starting material and sodium hydroxide as a precipitating agent. The resultant ceria-chitosan spheres were calcined at 350 {sup o}C. The synthesized powders were characterized by, XRD, HRTEM, UV-vis, FTIR, and TG-DTA. The average size of the nanoparticles obtained was {approx}4 nm and BET specific surface area {approx}105 m{sup 2} g{sup -1}. Blueshifts in the ultraviolet absorption spectra have been observed in cerium oxide nanocrystallites. The band-gap was found to be 4.5 eV. The blueshifts are well explained for diameters down to less than a few nanometers by the change in the electronic band structure.

  16. Uptake and cytotoxicity of chitosan nanoparticles in human liver cells

    SciTech Connect

    Loh, Jing Wen [Laboratory for Drug Delivery, Pharmacy, University of Western Australia, 35 Stirling Hwy, Crawley, 6009 (Australia); Yeoh, George [School of Biomedical, Biomolecular and Chemical Sciences, University of Western Australia, 35 Stirling Hwy, Crawley, 6009 (Australia); Centre for Medical Research, Western Australian Institute for Medical Research, Nedlands, WA 6009 (Australia); Saunders, Martin [Centre for Microscopy, Characterisation and Analysis, University of Western Australia, 35 Stirling Hwy, Crawley, 6009 (Australia); Lim, Lee-Yong, E-mail: limly@cyllene.uwa.edu.a [Laboratory for Drug Delivery, Pharmacy, University of Western Australia, 35 Stirling Hwy, Crawley, 6009 (Australia); School of Biomedical, Biomolecular and Chemical Sciences, University of Western Australia, 35 Stirling Hwy, Crawley, 6009 (Australia)

    2010-12-01

    Despite extensive research into the biomedical and pharmaceutical applications of nanoparticles, and the liver being the main detoxifying organ in the human body, there are limited studies which delineate the hepatotoxicity of nanoparticles. This paper reports on the biological interactions between liver cells and chitosan nanoparticles, which have been widely recognised as biocompatible. Using the MTT assay, human liver cells were shown to tolerate up to 4 h of exposure to 0.5% w/v of chitosan nanoparticles (18 {+-} 1 nm, 7.5 {+-} 1.0 mV in culture medium). At nanoparticle concentrations above 0.5% w/v, cell membrane integrity was compromised as evidenced by leakage of alanine transaminase into the extracellular milieu, and there was a dose-dependent increase in CYP3A4 enzyme activity. Uptake of chitosan nanoparticles into the cell nucleus was observed by confocal microscopic analysis after 4 h exposure with 1% w/v of chitosan nanoparticles. Electron micrographs further suggest necrotic or autophagic cell death, possibly caused by cell membrane damage and resultant enzyme leakage.

  17. Phase-separated chitosan–fibrin microbeads for cell delivery

    PubMed Central

    Chen, Zhewei; Wang, Limin; Stegemann, Jan P.

    2011-01-01

    Matrix-enhanced delivery of cells is a promising approach to improving current cell therapies. Our objective was to create cell-laden composite microbeads that combine the attractive features of the natural polymers chitosan and fibrin. Liquid polydimethylsiloxane was used to emulsify a chitosan–fibrinogen solution containing suspended human fibroblast cells, followed by initiation of thrombin-mediated polymerization of fibrin and thermal/pH-mediated gelation of chitosan. Chitosan/fibrin weight percent (wt%) ratios of 100/0, 75/25, 50/50 and 25/75 were investigated. Microbead diameters ranged from 275 ± 99 ?m to 38 ± 10 ?m using impeller speeds from 600 to 1400 rpm. Fibroblasts remained viable on day 1 post-fabrication in all matrices, but cell viability was markedly higher in high-fibrin microbeads by day 8 post-fabrication. Cell spreading and interaction with the extracellular matrix was also markedly increased in high-fibrin matrices. Such composite microbeads containing viable entrapped cells have potential for minimally invasive delivery of cells for a variety of tissue repair applications. PMID:21736519

  18. Cocatalyst effect in potassium persulfate initiated grafting onto chitosan

    Microsoft Academic Search

    J. Retuert; M. Yazdani-Pedram

    1993-01-01

    Methyl methacrylate and methyl acrylate were grafted onto chitosan by using potassium persulfate alone as redox initiator and in combination with MnCl2 and CuCl2, as inorganic, and both ammonium tartrate and oxalate as organic cocatalysts. The extent of grafting was found to depend mainly on the nature of the cocatalysts used.

  19. Imino-chitosan biopolymeric films. Obtaining, self-assembling, surface and antimicrobial properties.

    PubMed

    Marin, Luminita; Ailincai, Daniela; Mares, Mihai; Paslaru, Elena; Cristea, Mariana; Nica, Valentin; Simionescu, Bogdan C

    2015-03-01

    The paper reports the preparation of twelve imino-chitosan biopolymer films by acid condensation of the amino groups of chitosan with various aldehydes, in aqueous medium, followed by slow water removal. FTIR spectroscopy has shown drastic conformation changes of chitosan macromolecular chains—from a stiff coil to a straight one, while wide angle X-ray diffraction evidenced a layered morphology of the biopolymer films. Contact angle and surface free energy determination indicated a higher biocompatibility of the new biopolymers as compared to the chitosan parent, while the microbiological screening demonstrated their self-defense properties against common and virulent pathogen agents. It was concluded that the reversibility of imine forming promotes the self-assembling of imino-chitosan biopolymer films into a lamellar morphology and, on the other hand, the slow release of the antimicrobial aldehyde in the microbiological culture. The obtained results demonstrate that chitosan polyamine is a challenging workbench to functional biodynamic materials. PMID:25498698

  20. Microfluidic one-step synthesis of Fe?O?-chitosan composite particles and their applications.

    PubMed

    Yang, Chih-Hui; Wang, Chih-Yu; Huang, Keng-Shiang; Kung, Chao-Pin; Chang, Yi-Ching; Shaw, Jei-Fu

    2014-03-25

    This paper demonstrates a simple and easy approach for the one-step synthesis of Fe?O?-chitosan composite particles with tadpole-like shape. The length and diameter of the particles were adjustable from 638.3 ?m to ca. 798 ?m (length), and from 290 ?m to 412 ?m (diameter) by varying the flow rate of the dispersed phase. Mitoxantrone was used as the model drug in the drug release study. The encapsulation rate of the drug was 71% for chitosan particles, and 69% for magnetic iron oxide-chitosan particles, respectively. The iron oxide-chitosan composite particles had a faster release rate (up to 41.6% at the third hour) than the chitosan particles (about 24.6%). These iron oxide-chitosan composite particles are potentially useful for biomedical applications, such as magnetic responsive drug carriers, magnetic resonance imaging (MRI) enhancers, in the future. PMID:23988565

  1. Synthesis of hybrid polymer networks of irradiated chitosan/poly(vinyl alcohol) for biomedical applications

    NASA Astrophysics Data System (ADS)

    Islam, Atif; Yasin, Tariq; Rehman, Ihtesham ur

    2014-03-01

    Hybrid polymer network (HPN) of chitosan (CS) with poly(vinyl alcohol) (PVA) was prepared by using radiation degraded chitosan. The chemical structure of chitosan promoted chain scission reactions upon irradiation which lowered its molecular weight and also changed its hydrophilic balance. The effect of molecular weight and hydrophilicity of irradiated chitosan on structural, thermal and surface properties of the HPN were studied. The increased hydrophilicity of irradiated chitosan lowered the crystallinity of the HPN. The endothermic peak was shifted towards higher temperatures in HPN having irradiated chitosan. The decreased value of contact angle with increasing dose, further confirmed the increased hydrophilicity of the HPN. The cytotoxicity results of HPN showed the viability of human fibroblast cells and their non-toxic nature making it suitable for tissue engineering and other biomedical applications.

  2. Optimization of chitosan treatments for managing microflora in lettuce seeds without affecting germination.

    PubMed

    Goñi, M G; Moreira, M R; Viacava, G E; Roura, S I

    2013-01-30

    Many studies have focused on seed decontamination but no one has been capable of eliminating all pathogenic bacteria. Two objectives were followed. First, to assess the in vitro antimicrobial activity of chitosan against: (a) Escherichia coli O157:H7, (b) native microflora of lettuce and (c) native microflora of lettuce seeds. Second, to evaluate the efficiency of chitosan on reducing microflora on lettuce seeds. The overall goal was to find a combination of contact time and chitosan concentration that reduces the microflora of lettuce seeds, without affecting germination. After treatment lettuce seeds presented no detectable microbial counts (<10(2)CFU/50 seeds) for all populations. Moreover, chitosan eliminated E. coli. Regardless of the reduction in the microbial load, a 90% reduction on germination makes imbibition with chitosan, uneconomical. Subsequent treatments identified the optimal treatment as 10 min contact with a 10 g/L chitosan solution, which maintained the highest germination percentage. PMID:23218371

  3. Interaction of N-acylated and N-alkylated chitosans included in liposomes with lipopolysaccharide of gram-negative bacteria.

    PubMed

    Naberezhnykh, G A; Gorbach, V I; Likhatskaya, G N; Bratskaya, S Yu; Solov'eva, T F

    2013-03-01

    The interactions of lipopolysaccharide (LPS) with the polycation chitosan and its derivatives - high molecular weight chitosans (300 kDa) with different degree of N-alkylation, its quaternized derivatives, N-monoacylated low molecular weight chitosans (5.5 kDa) - entrapped in anionic liposomes were studied. It was found that the addition of chitosans changes the surface potential and size of negatively charged liposomes, the magnitudes of which depend on the chitosan concentration. Acylated low molecular weight chitosan interacts with liposomes most effectively. The binding of alkylated high molecular weight chitosan with liposomes increases with the degree of its alkylation. The analysis of interaction of LPS with chitoliposomes has shown that LPS-binding activity decreased in the following order: liposomes coated with a hydrophobic chitosan derivatives > coated with chitosan > free liposomes. Liposomes with N-acylated low molecular weight chitosan bind LPS more effectively than liposomes coated with N-alkylated high molecular weight chitosans. The increase in positive charge on the molecules of N-alkylated high molecular weight chitosans at the cost of quaternization does not lead to useful increase in efficiency of binding chitosan with LPS. It was found that increase in LPS concentration leads to a change in surface ?-potential of liposomes, an increase in average hydrodynamic diameter, and polydispersity of liposomes coated with N-acylated low molecular weight chitosan. The affinity of the interaction of LPS with a liposomal form of N-acylated chitosan increases in comparison with free liposomes. Computer simulation showed that the modification of the lipid bilayer of liposomes with N-acylated low molecular weight chitosan increases the binding of lipopolysaccharide without an O-specific polysaccharide with liposomes due to the formation of additional hydrogen and ionic bonds between the molecules of chitosan and LPS. PMID:23586725

  4. Cytotoxicity of monodispersed chitosan nanoparticles against the Caco-2 cells

    SciTech Connect

    Loh, Jing Wen [Laboratory for Drug Delivery, Pharmacy, Characterisation and Analysis, University of Western Australia (Australia)] [Laboratory for Drug Delivery, Pharmacy, Characterisation and Analysis, University of Western Australia (Australia); Saunders, Martin [Centre for Microscopy, Characterisation and Analysis, University of Western Australia (Australia)] [Centre for Microscopy, Characterisation and Analysis, University of Western Australia (Australia); Lim, Lee-Yong, E-mail: lee.lim@uwa.edu.au [Laboratory for Drug Delivery, Pharmacy, Characterisation and Analysis, University of Western Australia (Australia) [Laboratory for Drug Delivery, Pharmacy, Characterisation and Analysis, University of Western Australia (Australia); School of Biomedical, Biomolecular and Chemical Sciences, 35 Stirling Hwy, Crawley 6009 (Australia)

    2012-08-01

    Published toxicology data on chitosan nanoparticles (NP) often lack direct correlation to the in situ size and surface characteristics of the nanoparticles, and the repeated NP assaults as experienced in chronic use. The aim of this paper was to breach these gaps. Chitosan nanoparticles synthesized by spinning disc processing were characterised for size and zeta potential in HBSS and EMEM at pHs 6.0 and 7.4. Cytotoxicity against the Caco-2 cells was evaluated by measuring the changes in intracellular mitochondrial dehydrogenase activity, TEER and sodium fluorescein transport data and cell morphology. Cellular uptake of NP was observed under the confocal microscope. Contrary to established norms, the collective data suggest that the in vitro cytotoxicity of NP against the Caco-2 cells was less influenced by positive surface charges than by the particle size. Particle size was in turn determined by the pH of the medium in which the NP was dispersed, with the mean size ranging from 25 to 333 nm. At exposure concentration of 0.1%, NP of 25 ± 7 nm (zeta potential 5.3 ± 2.8 mV) was internalised by the Caco-2 cells, and the particles were observed to inflict extensive damage to the intracellular organelles. Concurrently, the transport of materials along the paracellular pathway was significantly facilitated. The Caco-2 cells were, however, capable of recovering from such assaults 5 days following NP removal, although a repeat NP exposure was observed to produce similar effects to the 1st exposure, with the cells exhibiting comparable resiliency to the 2nd assault. -- Highlights: ? Chitosan nanoparticles reduced mitochondrial dehydrogenase activity. ? Cellular uptake of chitosan nanoparticles was observed. ? Chitosan nanoparticles inflicted extensive damage to the cell morphology. ? The transport of materials along the paracellular pathway was facilitated.

  5. Modification of chitosan by using samarium for potential use in drug delivery system.

    PubMed

    Kusrini, Eny; Arbianti, Rita; Sofyan, Nofrijon; Abdullah, Mohd Aidil A; Andriani, Fika

    2014-01-01

    In the presence of hydroxyl and amine groups, chitosan is highly reactive; therefore, it could be used as a carrier in drug delivery. For this study, chitosan-Sm complexes with different concentrations of samarium from 2.5 to 25 wt.% have been successfully synthesized by the impregnation method. Chitosan combined with Sm3+ ions produced a drug carrier material with fluorescence properties; thus, it could also be used as an indicator of drug release with ibuprofen (IBU) as a model drug. We evaluated the spectroscopic and interaction properties of chitosan and Sm3+ ions, the interaction of chitosan-Sm matrices with IBU as a model drug, and the effect of Sm3+ ions addition on the chitosan ability to adsorb the drug. The result showed that the hypersensitive fluorescence intensity of chitosan-Sm (2.5 wt.%) is higher than the others, even though the adsorption efficiency of chitosan-Sm 2.5wt.% is lower (29.75%) than that of chitosan-Sm 25 wt.% (33.04%). Chitosan-Sm 25 wt.% showed the highest efficiency of adsorption of ibuprofen (33.04%). In the release process of ibuprofen from the chitosan-Sm-IBU matrix, the intensity of orange fluorescent properties in the hypersensitive peak of 4G5/2?6H7/2 transition at 590 nm was observed. Fluorescent intensity increased with the cumulative amount of IBU released; therefore, the release of IBU from the Sm-modified chitosan complex can be monitored by the changes in fluorescent intensity. PMID:24177873

  6. Metal removal through synergic coagulation–flocculation using an optimized chitosan–montmorillonite system

    Microsoft Academic Search

    E. Assaad; A. Azzouz; D. Nistor; A. V. Ursu; T. Sajin; D. N. Miron; F. Monette; P. Niquette; R. Hausler

    2007-01-01

    Metal cations were removed from water by coagulation–flocculation of the chitosan–montmorillonite system. Co2+, Ni2+ and Cu2+ were used as probe cations. It was found that both chitosan and montmorillonite contribute to the metal ion removal, when used separately, and that coagulation–flocculation strongly depends on the pH and composition of the liquid medium. When used simultaneously, chitosan and montmorillonite displayed a

  7. Effects of spray drying on physicochemical properties of chitosan acid salts.

    PubMed

    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

    2011-06-01

    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-MAS (13)C nuclear magnetic resonance (NMR), X-ray powder diffraction (XRPD), differential scanning calorimetry, and Fourier transform infrared spectrometry (FTIR) and near-infrared spectroscopy. The morphology of spray-dried chitosan acid salts showed tendency toward higher sphericity when higher temperatures in a spray-drying process were applied. Analysis by XRPD indicated that all chitosan acid salts studied were amorphous solids. Solid-state (13)C NMR spectra revealed the evidence of the partial conversion of chitosan acetate to chitin and also conversion to acetyl amide form which appears to be dependent on the spray-drying process. The FTIR spectra suggested that the organic acids applied in spray drying may interact with chitosan at the position of amino groups to form chitosan salts. With all three chitosan acid salts, the FTIR bands at 1,597 and 1,615 cm(-1) were diminished suggesting that -NH groups are protonated. The FTIR spectra of all chitosan acid salts exhibited ammonium and carboxylate bands at 1,630 and 1,556 cm(-1), respectively. In conclusion, spray drying is a potential method of preparing acid salts from chitosan obtained by deacetylation of chitin from lobster (P. argus) origin. PMID:21560022

  8. Chitosan for enhanced intestinal permeability: Prospects for derivatives soluble in neutral and basic environments

    Microsoft Academic Search

    A. F. Kotzé; H. L. Lueßen; A. G. de Boer; J. C. Verhoef; H. E. Junginger

    1999-01-01

    In this study the effects of two chitosan salts, namely chitosan hydrochloride and chitosan glutamate (0.5 and 1.5% w\\/v), on the transepithelial electrical resistance (TEER) and permeability of Caco-2 cell monolayers, using the radioactive marker [14C]-mannitol, were investigated in a slightly acidic (pH 6.2) and neutral (pH 7.4) environment. Both salts are soluble in acidic conditions up to a concentration

  9. In vitro characterization of chitosan–gelatin scaffolds for tissue engineering

    Microsoft Academic Search

    Yan Huang; Stella Onyeri; Mbonda Siewe; Aliakbar Moshfeghian; Sundararajan V. Madihally

    2005-01-01

    Recently, chitosan–gelatin scaffolds have gained much attention in various tissue engineering applications. However, the underlying cell–matrix interactions remain unclear in addition to the scaffold degradation and mechanical characteristics. In this study, we evaluated (i) the degradation kinetics of chitosan and chitosan–gelatin scaffolds in the presence of 10mg\\/L of lysozyme for dimensional stability, weight loss, and pH changes for a period

  10. Antibacterial activity of oleoyl-chitosan nanoparticles: A novel antibacterial dispersion system

    Microsoft Academic Search

    Ke Xing; Xi Guang Chen; Yan Yan Li; Cheng Sheng Liu; Chen Guang Liu; Dong Su Cha; Hyun Jin Park

    2008-01-01

    A novel chitosan antibacterial dispersion system was prepared by oleoyl-chitosan (O-chitosan) nanoparticles (OCNP), and the antibacterial activity against Escherichia coli and Staphylococcus aureus was investigated. Results showed that OCNP could be well distributed in nutrient broth and had strong antibacterial activity. The minimum inhibitory concentrations (MICs) of all OCNP samples ranged from 31.25 to 125mg\\/l against E. coli. For S.

  11. Adsorption of Cr(VI) on Cross?Linked Chitosan Beads

    Microsoft Academic Search

    Zofia Modrzejewska; Witold Sujka; Ma?gorzata Dorabialska; Roman Zarzycki

    2006-01-01

    A possibility of Cr(VI) removal by the adsorption method is discussed in the paper. An adsorbent were hydrogel chitosan beads are produced by the phase inversion method (by changing pH). The possibility of removing Cr(VI) ions by both pure chitosan hydrogel and its chelate compounds (chitosan cross?linked with Cu(II) and Ag(I) ions) was investigated. The adsorption proceeded from the solutions

  12. Recent advances on chitosan-based micro- and nanoparticles in drug delivery

    Microsoft Academic Search

    Sunil A. Agnihotri; Nadagouda N. Mallikarjuna; Tejraj M. Aminabhavi

    2004-01-01

    Considerable research efforts have been directed towards developing safe and efficient chitosan-based particulate drug delivery systems. The present review outlines the major new findings on the pharmaceutical applications of chitosan-based micro\\/nanoparticulate drug delivery systems published over the past decade. Methods of their preparation, drug loading, release characteristics, and applications are covered. Chemically modified chitosan or its derivatives used in drug

  13. Modification of chitosan films with environmentally benign reagents for increased water resistance

    Microsoft Academic Search

    Zheng Cui; Evan S. Beach; Paul T. Anastas

    2011-01-01

    Chitosan is a non-toxic, renewable, abundant natural material with excellent film-forming properties. It is shown here that water absorption by chitosan films can be decreased by chemical modification with the bio-based reagents citric acid and glycerol. Infrared spectroscopy showed that citric acid reacted with chitosan amine groups to form an acyclic amide structure. Glycerol imparted flexibility and water repellency to

  14. Quaternization of N-aryl chitosan derivatives: synthesis, characterization, and antibacterial activity

    Microsoft Academic Search

    Warayuth Sajomsang; Supawan Tantayanon; Varawut Tangpasuthadol; William H. Daly

    2009-01-01

    Chemical modification of chitosan by introducing quaternary ammonium moieties into the polymer backbone renders excellent antimicrobial activity to the adducts. In the present study, we have synthesized 17 derivatives of chitosan consisting of a variety of N-aryl substituents bearing either electron-donating or electron-withdrawing groups. Selective N-arylation of chitosan was performed via Schiff bases formed by the reaction between the 2-amino

  15. Quaternization of N-Aryl Chitosan Derivatives: Synthesis, Charaterization and Antibacterial Activity

    Microsoft Academic Search

    W. Sajomsang; W. H. Daly

    Chitosan (Ch) is aminoglucopyranans composed of N-acetylglucosamine (GlcNAc) and glucosamine (GlcN) residues. Chitosan is non-toxic, biodegradable and biocompatible polymer reported to exhibit a great variety of useful biological properties. It has been shown to be an effective agent against an array of common bacteria (Gram-positive as well as Gram- negative) and fungi. 1 However, the biological activity of chitosan can

  16. Mucoadhesive and floating chitosan-coated alginate beads for the controlled gastric release of amoxicillin

    Microsoft Academic Search

    Teerawat Sahasathian; Nalena Praphairaksit; Nongnuj Muangsin

    2010-01-01

    This work focused on the development of mucoadhesive and floating chitosan-coated alginate beads as a gastroretensive delivery\\u000a vehicle for amoxicillin, towards the effective eradication of Helicobacter pylori, a major causative agent of peptic ulcers. Alginate was used as the core bead core polymer and chitosan as the mucoadhesive\\u000a polymer coating. Amoxicillin-loaded alginate beads coated with 0.5% (w\\/v) chitosan (ALG\\/0.5%CHI) exhibited

  17. Chitosan Nanofibrous Scaffold Fabricated via Electrospinning: The Effect of Processing Parameters on the Nanofiber Morphology

    Microsoft Academic Search

    T. Mazoochi; V. Jabbari

    2011-01-01

    Chitosan nanofibers were electrospun by using chitosan and triflouroacetic acid (TFA) solution as a solvent. Morphological characteristics of chitosan nanofibers fabricated by the electrospinning technique in different applied voltages (15–25 kV) and tip-to-collector distances (TCD) (5–15 cm) were examined using scanning electron microscopy (SEM). SEM images of electrospun nanofibers showed that morphology and diameter of the nanofibers were mainly affected by applied

  18. Preparation and physical\\/electrochemical characterization of carbon nanotube–chitosan modified pencil graphite electrode

    Microsoft Academic Search

    Tayfun Vural; Filiz Kuralay; Cem Bayram; Serdar Abaci; Emir Baki Denkbas

    2010-01-01

    In this work, preparation and characterization of single-walled carbon nanotube–chitosan (SWNT–chitosan) modified disposable pencil graphite electrode (PGE) was carried out. Firstly, commercial single-walled carbon nanotube was purified and characterized using thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and energy dispersive analysis of X-ray (EDX) for this purpose. Purified SWNT was mixed with chitosan polymer

  19. Platelet adhesion and activation on an amphoteric chitosan derivative bearing sulfonate groups

    Microsoft Academic Search

    Mansoor M Amiji

    1998-01-01

    To improve blood compatibility of chitosan, a linear cationic polymer of d-glucosamine, we have synthesized an amphoteric derivative containing sulfonate functional groups. Unlike chitosan which is soluble only in acidic pH (<5.0), the sulfonated derivative was soluble over a wide pH range. Elemental analysis of N-sulfofurfuryl chitosan showed 5.20% sulfur content and the degree of substitution analysis confirmed 23.4% sulfofurfuryl

  20. Pluronic\\/chitosan shell cross-linked nanocapsules encapsulating magnetic nanoparticles

    Microsoft Academic Search

    Ki Hyun Bae; Young Jin Ha; Chunsoo Kim; Kyu-Ri Lee; Tae Gwan Park

    2008-01-01

    We have developed novel Pluronic\\/chitosan nanocapsules encapsulating iron oxide nanoparticles. These nanocapsules were produced by dispersing hydrophobically-modified iron oxide nanoparticles and amine-reactive Pluronic derivatives in an organic solvent, and subsequently emulsification in an aqueous chitosan solution by ultrasonication. The resultant shell cross-linked nanocapsules had a unique core\\/shell type nanoreservoir architecture: an inner core encapsulating magnetic nanoparticles and a hydrophilic Pluronic\\/chitosan

  1. The influence of the degree of cross-linking on the adsorption properties of chitosan beads

    Microsoft Academic Search

    Peter O. Osifo; Athena Webster; Hein van der Merwe; Hein W. J. P. Neomagus; Marius A. van der Gun; David M. Grant

    2008-01-01

    The influence of the degree of cross-linking (DCL) on chitosan beads was studied. Chitosan was prepared from the exoskeleton of Cape rock-lobsters, collected from the surroundings of Cape Town, South Africa. The chitosan beads were characterized; the beads water contents and pKa varied in the range of 90–96% and 4.3–6.0, respectively, and were found to decrease with increasing DCL (0.0–34.0%).

  2. Controlling cell adhesion and degradation of chitosan films by N-acetylation

    Microsoft Academic Search

    Thomas Freier; Hui Shan Koh; Karineh Kazazian; Molly S. Shoichet

    2005-01-01

    As part of our ongoing effort to develop a biodegradable nerve guidance channel based on chitin\\/chitosan, we conducted a systematic in vitro study on the biodegradation and neural cell compatibility of chitosan and N-acetylated chitosan. The in vitro degradation (pH 7.4, 37°C) in the presence of 1.5?g\\/ml lysozyme showed a progressive mass loss to greater than 50% within 4 weeks

  3. Preparation, characterization and antimicrobial activity of quaternized carboxymethyl chitosan and application as pulp-cap

    Microsoft Academic Search

    Liping Sun; Yumin Du; Lihong Fan; Xiao Chen; Jianhong Yang

    2006-01-01

    Quaternized carboxymethyl chitosan (QCMC) was prepared from which carboxymethyl chitosan (CMC) was prepared from chitosan first, then N-quaternary ammonium group was introduced by the reaction of CMC with 2, 3-epoxypropyl trimethylammonium. The structures of the derivatives were characterized by FT-IR, XRD, 13C NMR, 1H NMR and gel permeation chromatography. In vitro antimicrobial activities of QCMC were evaluated against Escherichia coli,

  4. Preparation and Characterization of Chitosan Coated Surgical Gauze Using Potassium Persulfate as Thermal Initiator

    Microsoft Academic Search

    Zinia Nasreen; Ruhul A. Khan; Mubarak A. Khan; A. I. Mustafa

    2009-01-01

    Chitosan powder was extracted from prawn shell via chitin formation by chemical treatment. Chitosan solution (2 wt.%) was prepared in aqueous solution containing ethanoic acid (2 wt.%) along with varying amounts of potassium persulphate as thermal initiator (10 to 50 mg). Surgical gauze was immersed in the chitosan solution for 10–45 min. Coating was carried out at 70–110°C and heating time varied from 30–180 min.

  5. Synthesis of Porous Cross-Linked Grafted Chitosan and Its Application for Metal Ion Adsorption

    Microsoft Academic Search

    Liu Hui

    2009-01-01

    A water-soluble intermediate bi-functional compound with thioureido and carboxyl groups was prepared by reacting chitosan with ammonium thiocyanate and chloroacetic acid. The intermediate compound was then cross-linked by epichlorohydrin to prepare a novel water-insoluble cross-linked chitosan aiming to be used as an adsorbent for heavy metal wastewater treatment. Both the intermediate compound and the cross-linked grafted chitosan (CGCTS) were characterized

  6. Porous chitosan scaffolds with surface micropatterning and inner porosity and their effects on Schwann cells.

    PubMed

    Li, Guicai; Zhao, Xueying; Zhao, Weixin; Zhang, Luzhong; Wang, Caiping; Jiang, Maorong; Gu, Xiaosong; Yang, Yumin

    2014-10-01

    Chitosan is found to promote the regeneration of peripheral nerve system in our previous studies, whereas the regeneration speed is not satisfied with clinical request. Micropatterning could promote cell orientation and growth, however, the effect of porous chitosan micropatterning on nerve regeneration is rarely reported. In this study, the porous chitosan micropatterning with surface ridge/groove and inner porosity structure was fabricated using a combination of micromodeling and lyophilization method. The morphology and stability of the prepared chitosan micropatterning were evaluated, the regulation of Schwann cells behavior by chitosan micropatterning was evaluated. The results showed that the chitosan micropatterning displayed stripe-like structure with a clear and complete edge. The micropatterning with 30/30 ?m was more stable than 20/20 ?m sample. Schwann cells on chitosan micropatterning showed orientation adhesion and began to grow along a certain direction after culture for 2 h, and displayed the minimal orientation angle and the largest length/width ratio on 30/30 ?m micropatterning after further culture for 3 d and 5 d, indicating the most obvious cell orientation. Moreover, the secretion of nerve growth factor (NGF) demonstrated that the micropatterned chitosan had no negative influence on the physiological function of Schwann cells. Thus, the results indicate that the porous chitosan micropatterning can regulate Schwann cell growth well, which may have potential application in nerve regeneration. The study provides an important basis for constructing porous nerve conduit with micropatterning structure in the inner wall. PMID:25002265

  7. Chitosan extracted from mud crab (Scylla olivicea) shells: physicochemical and antioxidant properties.

    PubMed

    Sarbon, N M; Sandanamsamy, S; Kamaruzaman, S F S; Ahmad, F

    2015-07-01

    The aim of this study is to report the yield of extraction, as well as the physicochemical and antioxidant properties of extracted chitosan from mud crabs (S.olivacea) as compared to commercial chitosan. The yield obtained for extracted chitosan was 44.57?±?3.44 % with a moisture and ash content of 9.48?±?0.59 % and 5.97?±?0.90 %, respectively. Commercial chitosan demonstrated a higher degree of deacetylation (58.42?±?2.67 %), water (250?±?9.90 %) and fat (329?±?7.07 %) binding capacity, solubility (73.85 %), viscosity (463.25?±?13.10 %) and also the whiteness value (77.8?±?0.47) compared to the extracted chitosan, which were only 53.42?±?0.88 %, 180?±?0.00 %, 260?±?0.00 %, 53.38 %, 383.9?±?28.43 % and 62.1?±?7.52 %, respectively. The structure of extracted and commercial chitosan was also investigated using Fourier Transform Infrared Spectroscopy (FTIR). In conclusion, the extracted chitosan possessed potential properties similar to the commercial chitosan with high reducing power but low in the scavenging activity on the DPPH and hydroxyl radicals compared to the commercial chitosan. PMID:26139891

  8. Applying the sensory analysis in the development of chitosan hydrogel containing polymeric nanocapsules for cutaneous use.

    PubMed

    Contri, Renata V; Külkamp-Guerreiro, Irene C; Krieser, Katherine; Pohlmann, Adriana R; Guterres, Sílvia S

    2014-01-01

    This work aimed to develop a chitosan hydrogel containing polymeric nanocapsules with optimized sensory properties, linking the advantages of the nanocarriers, such as controlled release and protection of the substances, to the chitosan properties, such as bioadherence, cicatrizing effect, and antimicrobial activity. Sixty untrained volunteers evaluated the sensory properties of chitosan hydrogels compared to hydroxyethyl cellulose gels (Phase I) and to optimized chitosan gels (Phase II). The volunteers' preference between formulations was also evaluated. The chitosan hydrogel, despite the presence of nanocapsules, presented higher immediate stickiness and film formation on the skin, and lower acceptance than the hydroxyethyl cellulose gels. Regarding the optimized gel, decrease on the film formation and increase on the homogeneity of the film was observed, compared to the prior chitosan gel. So, the optimization of the chitosan gel led to higher acceptance by the volunteers. The presence of nanocapsules, besides increasing the chitosan gel consistence, increased the perception of film formation. For the optimized chitosan gel, the nanocapsules increased the homogeneity of the film formed on the skin, without increasing the perception of film formation. In conclusion, through sensory analysis, the formulation was optimized presenting, at the final stage, adequate sensory properties for cutaneous use. PMID:25682621

  9. Grafting of chitosan as a biopolymer onto wool fabric using anhydride bridge and its antibacterial property.

    PubMed

    Ranjbar-Mohammadi, Marziyeh; Arami, Mokhtar; Bahrami, Hajir; Mazaheri, Firoozmehr; Mahmoodi, Niyaz Mohammad

    2010-04-01

    Weak binding of chitosan on the wool constitutes the main problem in its application. In this paper, the surface modification of wool fabric using anhydrides to graft the chitosan was studied. Weight gain, antibacterial and antifelting properties of the chitosan grafted-acylated wool fabric were investigated. Wool fabrics were acylated with two anhydrides, succinic anhydride (SA) and phthalic anhydride (PA), using different solvents (dimethylsulfoxide (DMSO) and N,N-dimethyl formamide (DMF)). The effects of anhydrides, solvents, anhydride concentration, liquor ratio (L:R) and reaction time on acylation of wool were investigated. Chitosan was grafted to the acylated wool and the effects of pH, chitosan concentration, and reaction time on chitosan grafting of acylated wool were evaluated. Fourier transform infra-red (FTIR), scanning electron microscope (SEM), differential scanning colorimetry (DSC) and weight gain analyses provided evidence that chitosan was grafted on to the acylated wool through the formation of new covalent bonds. The grafted samples have antibacterial potential due to existence of the antibacterial property of chitosan. In addition, the chitosan grafted-acylated wool samples have antifelting property. The findings of this research support the potential production of new environmentally friendly textile fabrics. PMID:20022732

  10. Sorption of heavy metal ions onto carboxylate chitosan derivatives--a mini-review.

    PubMed

    Boamah, Peter Osei; Huang, Yan; Hua, Mingqing; Zhang, Qi; Wu, Jingbo; Onumah, Jacqueline; Sam-Amoah, Livingstone K; Boamah, Paul Osei

    2015-06-01

    Chitosan is of importance for the elimination of heavy metals due to their outstanding characteristics such as the presence of NH2 and -OH functional groups, non-toxicity, low cost and, large available quantities. Modifying a chitosan structure with -COOH group improves it in terms of solubility at pH ?7 without affecting the aforementioned characteristics. Chitosan modified with a carboxylic group possess carboxyl, amino and hydroxyl multifunctional groups which are good for elimination of metal ions. The focal point of this mini-review will be on the preparation and characterization of some carboxylate chitosan derivatives as a sorbent for heavy metal sorption. PMID:25791666

  11. Green Conversion of Agroindustrial Wastes into Chitin and Chitosan by Rhizopus arrhizus and Cunninghamella elegans Strains

    PubMed Central

    Berger, Lúcia Raquel Ramos; Stamford, Thayza Christina Montenegro; Stamford-Arnaud, Thatiana Montenegro; de Alcântara, Sergio Roberto Cabral; da Silva, Antonio Cardoso; da Silva, Adamares Marques; do Nascimento, Aline Elesbão; de Campos-Takaki, Galba Maria

    2014-01-01

    This article sets out a method for producing chitin and chitosan by Cunninghamella elegans and Rhizopus arrhizus strains using a green metabolic conversion of agroindustrial wastes (corn steep liquor and molasses). The physicochemical characteristics of the biopolymers and antimicrobial activity are described. Chitin and chitosan were extracted by alkali-acid treatment, and characterized by infrared spectroscopy, viscosity and X-ray diffraction. The effectiveness of chitosan from C. elegans and R. arrhizus in inhibiting the growth of Listeria monocytogenes, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella enterica, Escherichia coli and Yersinia enterocolitica were evaluated by determining the minimum inhibitory concentrations (MIC) and the minimum bactericidal concentrations (MBC). The highest production of biomass (24.60 g/L), chitin (83.20 mg/g) and chitosan (49.31 mg/g) was obtained by R. arrhizus. Chitin and chitosan from both fungi showed a similar degree of deacetylation, respectively of 25% and 82%, crystallinity indices of 33.80% and 32.80% for chitin, and 20.30% and 17.80% for chitosan. Both chitin and chitosan presented similar viscosimetry of 3.79–3.40 cP and low molecular weight of 5.08 × 103 and 4.68 × 103 g/mol. They both showed identical MIC and MBC for all bacteria assayed. These results suggest that: agricultural wastes can be produced in an environmentally friendly way; chitin and chitosan can be produced economically; and that chitosan has antimicrobial potential against pathogenic bacteria. PMID:24853288

  12. 40 CFR 180.1072 - Poly-D-glucosamine (chitosan); exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Poly-D-glucosamine (chitosan); exemption from the requirement of a tolerance. 180...From Tolerances § 180.1072 Poly-D -glucosamine (chitosan); exemption from the requirement of a tolerance....

  13. 40 CFR 180.1072 - Poly-D-glucosamine (chitosan); exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Poly-D-glucosamine (chitosan); exemption from the requirement of a tolerance. 180...From Tolerances § 180.1072 Poly-D -glucosamine (chitosan); exemption from the requirement of a tolerance....

  14. Biomimetic apatite-coated alginate/chitosan microparticles as osteogenic protein carriers

    PubMed Central

    Lee, Min; Li, Weiming; Siu, Ronald K.; Whang, Julie; Zhang, Xinli; Soo, Chia; Ting, Kang; Wu, Benjamin M.

    2009-01-01

    Bone morphogenetic proteins (BMPs) are currently approved for spinal fusion, tibial fracture repair, and maxillofacial bone regeneration. However, BMP pleiotropism, paradoxical activities on precursor cells, and unexpected side effects at local and ectopic sites may limit their usage. Thus, the need remains for alternative osteoinductive factors that provide more bone-specific activities with fewer adverse effects. Nell-1 [Nel-like molecule-1; Nel (a protein highly expressed in neural tissue encoding epidermal growth factor like domain)] is a novel osteogenic protein believed to specifically target cells committed to the osteogenic lineage. The objective of this project is to incorporate Nell-1 into a moldable putty carrier that can adapt to bony defects and deliver Nell-1 to the local microenvironment. We show here that moldability can be achieved by mixing hyaluronan hydrogel with two types of particles: demineralized bone powder for osteoconductivity, and biomimetic apatite-coated alginate/chitosan microparticles for controlled Nell-1 delivery. Besides enhancing overall osteoconductivity of the carrier, the biomimetic apatite coating also provides a more sustained release (? 15% cumulative release over 30 days) and greatly reduces the initial burst release that is observed with non-coated alginate/chitosan microparticles (? 40% release after 1 day). The efficacy of Nell-1 delivery from these carriers was evaluated in a rat spinal fusion model against Nell-free carriers as controls. 4 weeks post-implantation, Nell-1 enhanced spinal fusion rates as measured by manual palpation, radiographs, high resolution micro-computerized tomography (?CT), and histology. This moldable putty carrier system appears to be a suitable carrier for promoting osteogenesis, and will be further evaluated in larger animal models over longer periods to follow the remodeling of the regenerated bone. PMID:19674782

  15. Application of Chitosan Microparticles for Reduction of Vibrio Species in Seawater and Live Oysters (Crassostrea virginica)

    PubMed Central

    Fang, Lei; Wolmarans, Bernhard; Kang, Minyoung; Jeong, Kwang C.

    2014-01-01

    Human Vibrio infections associated with consumption of raw shellfish greatly impact the seafood industry. Vibrio cholerae-related disease is occasionally attributed to seafood, but V. vulnificus and V. parahaemolyticus are the primary targets of postharvest processing (PHP) efforts in the United States, as they pose the greatest threat to the industry. Most successful PHP treatments for Vibrio reduction also kill the molluscs and are not suitable for the lucrative half-shell market, while nonlethal practices are generally less effective. Therefore, novel intervention strategies for Vibrio reduction are needed for live oyster products. Chitosan is a bioactive derivative of chitin that is generally recognized as safe as a food additive by the FDA, and chitosan microparticles (CMs) were investigated in the present study as a potential PHP treatment for live oyster applications. Treatment of broth cultures with 0.5% (wt/vol) CMs resulted in growth cessation of V. cholerae, V. vulnificus, and V. parahaemolyticus, reducing culturable levels to nondetectable amounts after 3 h in three independent experiments. Furthermore, a similar treatment in artificial seawater at 4, 25, and 37°C reduced V. vulnificus levels by ca. 7 log CFU/ml after 24 h of exposure, but 48 h of exposure and elevated temperature were required to achieve similar results for V. parahaemolyticus and V. cholerae. Live oysters that either were artificially inoculated or contained natural populations of V. vulnificus and V. parahaemolyticus showed significant and consistent reductions following CM treatment (5%) compared to the amounts in the untreated controls. Thus, the results strongly support the promising potential for the application of CMs as a PHP treatment to reduce Vibrio spp. in intact live oysters. PMID:25381244

  16. Non-isothermal kinetics of thermal degradation of chitosan

    PubMed Central

    2012-01-01

    Background Chitosan is the second most abundant nitrogen containing biopolymer in nature, obtained from the shells of crustaceans, particularly crabs, shrimp and lobsters, which are waste products of seafood processing industries. It has great potential application in the areas of biotechnology, biomedicine, food industries, and cosmetics. Chitosan is also capable of adsorbing a number of metal ions as its amino groups can serve as chelation sites. Grafted functional groups such as hydroxyl, carboxyl, sulfate, phosphate, and amino groups on the chitosan have been reported to be responsible for metal binding and sorption of dyes and pigments. The knowledge of their thermal stability and pyrolysis may help to better understand and plan their industrial processing. Results Thermogravimetric studies of chitosan in air atmosphere were carried out at six rates of linear increasing of the temperature. The kinetics and mechanism of the thermal decomposition reaction were evaluated from the TG data using recommended from ICTAC kinetics committee iso-conversional calculation procedure of Kissinger-Akahira-Sunose, as well as 27 mechanism functions. The comparison of the obtained results showed that they strongly depend on the selection of proper mechanism function for the process. Therefore, it is very important to determine the most probable mechanism function. In this respect the iso-conversional calculation procedure turned out to be the most appropriate. Conclusion Chitosan have excellent properties such as hydrophilicity, biocompatibility, biodegradability, antibacterial, non-toxicity, adsorption application. The thermal degradation of chitosan occurs in two stages. The most probable mechanism function for both stages is determined and it was best described by kinetic equations of n-th order (Fn mechanism). For the first stage, it was established that n is equal to 3.0 and for the second stage – to 1.0 respectively. The values of the apparent activation energy E, pre-exponential factor A in Arrhenius equation, as well as the changes of entropy ?S?, enthalpy ?H? and free Gibbs energy ?G? for the formation of the activated complex from the reagent are calculated. PMID:22857524

  17. Effects of chitosan and plant extracts on growth of Colletotrichum gloeosporioides, anthracnose levels and quality of papaya fruit

    Microsoft Academic Search

    S. Bautista-Baños; M. Hernández-López; E. Bosquez-Molina; C. L. Wilson

    2003-01-01

    The objectives of this research were to evaluate the in vitro fungicidal effect of chitosan and aqueous extracts of custard apple leaves, papaya leaves and papaya seeds, and the combination of chitosan and plant extracts on the development of Colletotrichum gloeosporioides, which causes anthracnose on papaya. Chitosan at 2.0% and 3.0% had a fungicidal effect on C. gloeosporioides. Extracts alone

  18. Development and in vitro evaluation of chitosan-based transdermal drug delivery systems for the controlled delivery of propranolol hydrochloride

    Microsoft Academic Search

    D. Thacharodi; K. Panduranga Rao

    1995-01-01

    Membrane permeation-controlled transdermal drug delivery systems were prepared using the natural polymer, chitosan. An adhesive sealing technique was used to construct the devices. Propranolol hydrochloride was selected as the model drug for the present study. Chitosan membranes with different permeability to propranolol hydrochloride obtained by controlled cross-linking with glutaraldehyde were used to regulate the drug release in the devices. Chitosan

  19. Pd and Pt recovery using chitosan gel beads. I. Influence of the drying process on diffusion properties

    Microsoft Academic Search

    M. Ruiz; A. Sastre; E. Guibal

    2002-01-01

    Chitosan is very efficient at removing metal ions, especially precious metals. Sorption kinetics can be improved by the preparation of chitosan gel beads, using a coagulation procedure. However, this process leads to the formation of beads containing very high water yields, which prevent chitosan from being an economically competitive sorbent for large-scale industrial applications, for reasons linked to transport costs

  20. Effect of Chitosan Dissolved in Different Acids on its Ability to Control Postharvest Gray Mold of Table Grape

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chitosan is a natural biopolymer that must be dissolved in an acid solution to activate its antimicrobial and eliciting properties. Among 15 acids, chitosan dissolved in 1% solutions of acetic, L-ascorbic, formic, L-glutamic, hydrochloric, lactic, maleic, malic, phosphorous, and succinic. Chitosan s...

  1. Development of silver/titanium dioxide/chitosan adipate nanocomposite as an antibacterial coating for fruit storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A novel nanocomposite of silver/titanium dioxide/chitosan adipate (Ag/TiO2/CS) was developed through photochemical reduction using a chitosan adipate template. Chitosan served as a reducing agent for the metal ions, and anchored metal ions by forming Ag–N coordination bonds and electrostatic attract...

  2. Development and characterization of novel organic coatings based on biopolymer chitosan

    NASA Astrophysics Data System (ADS)

    Kumar, Girdhari

    Chitosan, a derivative of naturally abundant biopolymer chitin, was used as the basis for corrosion resistant coating. Chitosan suffers from two inherent weaknesses as a coating material, namely its high hydrophilicity and its poor adhesive strength with Al 2024 T3 alloy. In the present study, the chitosan structure was modified using epoxy functional silane and vanadate. Two epoxy functional silanes (3-Glycidoxypropyl)-trimethoxysilane (GPTS) and (2-(3,4-epoxycyclohexyl)-ethyltrimethoxysilane (ECET) were tested. The performance of different coatings was tested using electrochemical impedance spectroscopy, adhesion testing and salt spray testing. Addition of GPTS resulted in improvement in corrosion resistance and adhesive strength. Chitosan-GPTS-vanadate coatings prepared using chitosan-GPTS solution at viscosity 0.96 pa-s and post treated in NaVO3 solution at pH 6-8 demonstrated the highest corrosion resistance. The best salt spray performance was observed in case of chitosan-GPTS-vanadate coatings, which lasted 450 hours in salt spray chamber. Detailed fundamental characterization was carried out related to the structure, chemistry and properties of chitosan-based coatings using optical spectroscopy. FTIR spectra of chitosan gel showed adsorption of vanadate at protonated amine sites of chitosan. Chitosan showed a maximum in the vanadate adsorption capacity when treated in NaVO3 solution at pH 3-5. GPTS reacted with amine functional group of chitosan and, at the same time, formed a hydrophobic siloxane network with the Al alloy substrate. Formation of a siloxane network with the Al substrate provided the observed increase in corrosion and adhesive strength of the coatings. UV/Visible spectroscopy measurements showed release of vanadate by chitosan increases with increasing solution pH, increasing chloride concentration and polarizing the sample cathodically. Structured experiments have been used to show that vanadate is reversibly bound to chitosan. Adsorption and release have been found to depend strongly on the pH of the aqueous solution contacting the chitosan coating. When the solution pH is readjusted to a lower value, chitosan can re-adsorb released vanadate. Further, a direct electrochemically triggered release of inhibitor was demonstrated by cathodically polarizing the coated sample. Release of vanadate under different conditions demonstrated the on demand inhibitor release capability of the coatings. This capability of coating is useful to provide a self-healing effect.

  3. Degradation of chitosan by gamma ray with presence of hydrogen peroxide

    SciTech Connect

    Mahmud, Maznah; Yacob, Norzita; Talip, Norhashidah; Abdullah, Zahid [Malaysian Nuclear Agency, Radiation Technology Division, Bangi, 43000 Kajang, Selangor (Malaysia); Naziri, Muhammad Ihsan [University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2014-02-12

    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 (H{sub 2}O{sub 2}), 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 H{sub 2}O{sub 2} enhanced the degradation rate of chitosan even at very low irradiation dose. Homogenous degradation also occurred during treatment with H{sub 2}O{sub 2}based 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.

  4. Role of chitosan co-formulation in enhancing interleukin-12 delivery and antitumor activity.

    PubMed

    Yang, Lirong; Zaharoff, David A

    2013-05-01

    Local delivery systems that provide sustained, high concentrations of antitumor cytokines in the tumor microenvironment while minimizing systemic dissemination are needed to realize the potential of cytokine-based immunotherapies. Recently, co-formulations of cytokines with chitosan solutions have been shown to increase local cytokine retention and bioactivity. In particular, intratumoral (i.t.) injections of chitosan/IL-12 can eliminate established tumors and generate tumor-specific immune responses. In the present study, we explored the mechanisms by which chitosan potentiated IL-12's antitumor activity. The location of chitosan/IL-12 injection was found to be critical for optimal cytokine delivery. I.t. injections eliminated 9 of 10 MC38 adenocarcinomas while contralateral and peritumoral injections delayed tumor growth but could not eliminate tumors. Microdosing studies demonstrated that IL-12 depots, simulated through daily i.t. injections with IL-12 alone, were not as effective as weekly i.t. chitosan/IL-12. 50-75% of mice receiving daily IL-12 microdoses and 87.5% of mice receiving weekly chitosan/IL-12 were cured of MC38 tumors. Chitosan was found to increase IL-12-mediated leukocytic expansion in tumors and tumor-draining lymph nodes (TDLNs) by 40 and 100%, respectively. Immunophenotyping studies demonstrated that chitosan co-formulation amplified IL-12-induced increases in important effector populations, such as CD8(+)IFN-?(+) and NKT cells, in tumors and dendritic cell populations in TDLNs. Remarkable increases in Gr-1(+)CD11b(+) tumor infiltrates were also observed in mice receiving chitosan or chitosan/IL-12. This population does not appear be suppressive and may facilitate the local antitumor response. Presented data suggest that chitosan-mediated depot formation and enhanced local cytokine retention is significantly, but not entirely, responsible for increased cytokine bioactivity. PMID:23453060

  5. Plant cell death caused by fungal, bacterial, and viral elicitors: protective effect of mitochondria-targeted quinones.

    PubMed

    Kiselevsky, D B; Frolova, O Yu; Solovyev, A G; Dorokhov, Yu L; Morozov, S Yu; Samuilov, V D

    2014-12-01

    Chitosan (partially deacetylated chitin), a component of fungal cell walls, caused epidermal cell (EC) death in the leaves of pea (Pisum sativum L.) and tobacco Nicotiana tabacum or Nicotiana benthamiana detected by destruction of cell nuclei. The mitochondria-targeted quinone SkQ1 prevented the destruction of EC nuclei induced by chitosan. Chitosan increased and SkQ1 suppressed the activity of protein kinases in N. benthamiana and P. sativum and eliminated the effect of chitosan. Chitosan induced the generation of reactive oxygen species (ROS) in the guard cells (GC) of pea plants. Treatment with chitosan or H2O2 did not cause destruction of GC nuclei; however, it resulted in disruption of the permeability barrier of the plasma membrane detected by propidium iodide fluorescence. Treatment with bacterial lipopolysaccharide but not peptidoglycan caused destruction of pea EC nuclei, which was prevented by SkQ1. Leaves of tobacco plants containing the N gene responsible for resistance to tobacco mosaic virus (TMV) were infiltrated with Agrobacterium tumefaciens cells. These cells contained a genetic construct with the gene of the helicase domain of TMV replicase (p50); its protein product p50 is a target for the N-gene product. As a result, the hypersensitive response (HR) was initiated. The HR manifested itself in the death of leaves and was suppressed by SkQ3. Treatment of tobacco epidermal peels with the A. tumefaciens cells for the p50 gene expression stimulated the destruction of EC nuclei, which was inhibited by SkQ1 or SkQ3. The p50-lacking A. tumefaciens cells did not induce the destruction of EC nuclei. The protective effect of mitochondria-targeted antioxidants SkQ1 and SkQ3 demonstrates the involvement of mitochondria and their ROS in programmed cell death caused by pathogen elicitors. PMID:25716725

  6. Barley mildew and its elicitor chitosan promote closed stomata by stimulating guard-cell S-type anion channels.

    PubMed

    Koers, Sandra; Guzel-Deger, Aysin; Marten, Irene; Roelfsema, M Rob G

    2011-11-01

    Stomatal closure is known to be associated with early defence responses of plant cells triggered by microbe-associated molecular patterns (MAMPs). However, the molecular mechanisms underlying these guard-cell responses have not yet been elucidated. We therefore studied pathogen-induced changes in ion channel activity in Hordeum vulgare guard cells. Barley mildew (Blumeria graminis) hyphae growing on leaves inhibited light-induced stomatal opening, starting at 9 h after inoculation, when appressoria had developed. Alternatively, stomatal closure was induced by nano-infusion of chitosan via open stomata into the sub-stomatal cavity. Experiments using intracellular double-barreled micro-electrodes revealed that mildew stimulated S-type (slow) anion channels in guard cells. These channels enable the efflux of anions from guard cells and also promote K(+) extrusion by altering the plasma membrane potential. Stimulation of S-type anion channels was also provoked by nano-infusion of chitosan. These data suggest that MAMPs of mildew hyphae penetrating the cuticle provoke activation of S-type anion channels in guard cells. In response, guard cells extrude K(+) salts, resulting in stomatal closure. Plasma membrane anion channels probably represent general targets of MAMP signaling in plants, as these elicitors depolarize the plasma membrane of various cell types. PMID:21781196

  7. Regioselective Sequential Modification of Chitosan via Azide-Alkyne Click Reaction: Synthesis, Characterization, and Antimicrobial Activity of Chitosan Derivatives and Nanoparticles

    PubMed Central

    Sarwar, Atif; Katas, Haliza; Samsudin, Siti Noradila; Zin, Noraziah Mohamad

    2015-01-01

    Recently, the attention of researchers has been drawn toward the synthesis of chitosan derivatives and their nanoparticles with enhanced antimicrobial activities. In this study, chitosan derivatives with different azides and alkyne groups were synthesized using click chemistry, and these were further transformed into nanoparticles by using the ionotropic gelation method. A series of chitosan derivatives was successfully synthesized by regioselective modification of chitosan via an azide-alkyne click reaction. The amino moieties of chitosan were protected during derivatization by pthaloylation and subsequently unblocked at the end to restore their functionality. Nanoparticles of synthesized derivatives were fabricated by ionic gelation to form complexes of polyanionic penta-sodium tripolyphosphate (TPP) and cationic chitosan derivatives. Particle size analysis showed that nanoparticle size ranged from 181.03 ± 12.73 nm to 236.50 ± 14.32 nm and had narrow polydispersity index and positive surface charge. The derivatives and corresponding nanoparticles were evaluated in vitro for antibacterial and antifungal activities against three gram-positive and gram-negative bacteria and three fungal strains, respectively. The minimum inhibitory concentration (MIC) of all derivatives ranged from 31.3 to 250 µg/mL for bacteria and 188 to1500 µg/mL for fungi and was lower than that of native chitosan. The nanoparticles with MIC ranging from 1.56 to 25 µg/mLfor bacteria and 94 to 750 µg/mL for fungi exhibited higher activity than the chitosan derivatives. Chitosan O-(1-methylbenzene) triazolyl carbamate and chitosan O-(1-methyl phenyl sulfide) triazolyl carbamate were the most active against the tested bacterial and fungal strains. The hemolytic assay on erythrocytes and cell viability test on two different cell lines (Chinese hamster lung fibroblast cells V79 and Human hepatic cell line WRL68) demonstrated the safety; suggesting that these derivatives could be used in future medical applications. Chitosan derivatives with triazole functionality, synthesized by Huisgen 1,3-dipolar cycloaddition, and their nanoparticles showed significant enhancement in antibacterial and antifungal activities in comparison to those associated with native, non-altered chitosan. PMID:25928293

  8. Adsorption of chitosan on BN nanotubes: A DFT investigation

    NASA Astrophysics Data System (ADS)

    Juárez, A. Rodríguez; Anota, E. Chigo; Cocoletzi, H. Hernández; Riveros, A. Flores

    2013-03-01

    The adsorption of the biopolymer chitosan on the (5,0) and (5,5) boron nitride nanotubes (BNNTs) was theoretically analyzed by Molecular Simulations. The calculations were done using the well known density-functional theory within the local density approximation; the exchange-correlation term was modeled with the Perdew-Wang parameterization. The structural stability was based on the obtention of the minimum energy and non-complex vibrational frequencies. Different sites, charge (neutral, cation and anion) and orientations of chitosan, using the monomer unit, were considered. For the (5,5) nanotube, the minimum energy site corresponds to that when the monomer (for all charges assigned) is perpendicular to the nanotube; only structural stability was found in the anion assignment for the (5,0) nanotube. The chemisorption process is through the amine group modifying the semiconductor character of the nanotube to semimetallic one, with ionic properties, suggesting their solubilization on hydrophilic nanomaterials.

  9. Chitosan Hydrogels for Chondroitin Sulphate Controlled Release: An Analytical Characterization

    PubMed Central

    Bianchera, Annalisa; Salomi, Enrico; Pezzanera, Matteo; Ruwet, Elisabeth; Bettini, Ruggero; Elviri, Lisa

    2014-01-01

    This paper provides an analytical characterization of chitosan scaffolds obtained by freeze-gelation toward the uptake and the controlled release of chondroitin sulphate (CS), as cartilage repair agent, under different pH conditions. Scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and liquid chromatography-UV spectrophotometry (LC-UV) techniques were exploited to obtain qualitative and quantitative descriptions of polymer and drug behaviour in the biomaterial. As for morphology, SEM analysis allowed the evaluation of scaffold porosity in terms of pore size and distribution both at the surface (Feret diameter 58 ± 19??m) and on the cross section (Feret diameter 106 ± 51??m). LC and ATR-FTIR evidenced a pH-dependent CS loading and release behaviour, strongly highlighting the role of electrostatic forces on chitosan/chondroitin sulphate interactions. PMID:25614850

  10. Self-scrolling ability of differentially acetylated chitosan film.

    PubMed

    Saito, Yukie; Luchnikov, Valeriy; Inaba, Ayano; Tamura, Katsuhito

    2014-08-30

    Chitosan film cast on a glass slide was exposed to acetic anhydride vapor, resulting in an acetylation gradient in the film, with preferential acetylation of the exposed surface. The difference in degree of acetylation between the two surfaces of the peeled film was confirmed by attenuated total reflection infrared spectroscopy. Upon immersion of the film in water, differential swelling occurred because the more highly acetylated surface absorbed less water, and the resulting bending moment caused self-scrolling with the more highly acetylated surface inside. Simultaneous peeling and scrolling of films with a thickness of micrometer order, using dilute aqueous hydrofluoric acid, afforded tightly rolled chitosan microtubes. This simple self-scrolling mechanism is potentially applicable for micro-scale design with various naturally occurring polymers. PMID:24815399

  11. Preparation and characterization of nano-hydroxyapatite within chitosan matrix.

    PubMed

    Rogina, A; Ivankovi?, M; Ivankovi?, H

    2013-12-01

    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. PMID:24094157

  12. Chitosan/alginate complexes for vaginal delivery of chlorhexidine digluconate.

    PubMed

    Abruzzo, A; Bigucci, F; Cerchiara, T; Saladini, B; Gallucci, M C; Cruciani, F; Vitali, B; Luppi, B

    2013-01-16

    Chitosan/alginate complexes were prepared at different polycation/polyanion molar ratios and freeze-dried vaginal inserts were obtained for chlorhexidine digluconate local delivery in genital infections. Complex yield, FT-IR spectra, and TGA thermograms were studied to confirm the interaction between the two polyions. The influence of different complexes on physical handling, morphology, and drug distribution in the samples were evaluated by friability test, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS), respectively. In vitro water-uptake, mucoadhesion and release tests were performed as well as microbiological tests toward pathogenic vaginal microorganisms. The results showed that the selection of suitable chitosan/alginate molar ratio and drug loading allowed modulate insert ability to hydrate, adhere to the mucosa, and release chlorhexidine digluconate. The insert containing an excess of alginate was found to be the best performing formulation and showed good antimicrobial activity toward the pathogens Candida albicans and Escherichia coli. PMID:23121960

  13. Graphene oxide cross-linked chitosan nanocomposite membrane

    NASA Astrophysics Data System (ADS)

    Shao, Lu; Chang, Xiaojing; Zhang, Yongling; Huang, Yifeng; Yao, Yuhuan; Guo, Zhanhu

    2013-09-01

    Graphene oxide (GO) cross-linked chitosan (CS) nanocomposite membrane is firstly reported in this study. At elevated temperatures, the cross-linking reaction between amino groups of CS and epoxy groups of GO happens which significantly affects the properties of membranes. The physicochemical properties of nanocomposite membranes have been examined by various methods including the gel content test, Fourier transform infrared (FTIR), differential scanning calorimeter (DSC), scanning electron microscope (SEM), transmission electron microscope (TEM) and tensile strength test. Interestingly, the tensile strength of chitosan membranes is greatly improved by GO incorporation. The 1 wt% loading of GO can improve the tensile strength from 43.2 MPa to 104.2 MPa with the increment of 141%. This should be attributed to the effective load transfer between GO and CS arising from the good interfacial properties after cross-linking reactions. Therefore, the biocompatible nanocomposite membranes with enhanced physicochemical properties are promising for diverse applications.

  14. Lysozyme depolymerization of photo-activated chitosan adhesive films.

    PubMed

    Mawad, Damia; Warren, Charles; Barton, Mathew; Mahns, David; Morley, John; Pham, Binh T T; Pham, Nguyen T H; Kueh, Sindy; Lauto, Antonio

    2015-05-01

    Effective tissue bioadhesion of rose bengal-chitosan films can be achieved by photoactivation using a green laser. In this study, lysozyme was incorporated in these films to enhance the rate of depolymerization and assess the laser impact on lysozyme. The lysozyme loaded films exhibited a 21% mass loss after 4 weeks implantation in rats while control films (without lysozyme) had only 7% mass loss. Capillary electrophoresis-mass spectroscopy showed that chitosan degraded into monomers and oligomers of glucosamine and N-acetyl-glucosamine. Irradiation with laser did not affect the depolymerization of adhesive by lysozyme suggesting that the inclusion of lysozyme in the bioadhesive is a viable technique for tailoring the depolymerization. PMID:25659671

  15. Chitin nanofibrils\\/chitosan glycolate composites as wound medicaments

    Microsoft Academic Search

    Riccardo A. A. Muzzarelli; Pierfrancesco Morganti; Gianluca Morganti; Paolo Palombo; Marco Palombo; Graziella Biagini; Monica Mattioli Belmonte; Federica Giantomassi; Fiorenza Orlandi; Corrado Muzzarelli

    2007-01-01

    Highly crystalline chitin nanofibrils were isolated from crustacean chitin and characterized by X-ray diffraction and FT-infrared spectrometry. A novel formulation including chitin nanofibrils, chitosan glycolate, and chlorhexidine was manufactured in three presentations: spray, gel, and gauze. The latter included non-woven dibutyryl chitin as a biocompatible support. The products were tested in murine wound models, with phytostimuline-medicated wounds as controls, in

  16. Preparation of magnetic chitosan nanoparticles and immobilization of laccase

    Microsoft Academic Search

    Hua Fang; Jun Huang; Liyun Ding; Mingtian Li; Zhao Chen

    2009-01-01

    The magnetic chitosan nanoparticles were prepared by reversed-phase suspension method using Span-80 as an emulsifier, glutaraldehyde\\u000a as cross-linking reagent. And the nanoparticles were characterized by TEM, FT-IR and hysteresis loop. The results show that\\u000a the nanoparticles are spherical and almost superparamagnetic. The laccase was immobilized on nanoparticles by adsorption and\\u000a subsequently by cross-linking with glutaraldehyde. The immobilization conditions and characterizations

  17. Transcript profiling of chitosan-treated Arabidopsis seedlings

    Microsoft Academic Search

    Giovanni Povero; Elena Loreti; Chiara Pucciariello; Antonietta Santaniello; Donata Di Tommaso; Gianluca Di Tommaso; Dimos Kapetis; Francesca Zolezzi; Alberto Piaggesi; Pierdomenico Perata

    In nature, plants can recognize potential pathogens, thus activating intricate networks of defense signals and reactions.\\u000a Inducible defense is often mediated by the detection of microbe or pathogen associated molecular pattern elicitors, such as\\u000a flagellin and chitin. Chitosan, the deacetylated form of chitin, plays a role in inducing protection against pathogens in\\u000a many plant species. We evaluated the ability of

  18. Chitosan implants in the rat spinal cord: biocompatibility and biodegradation.

    PubMed

    Kim, Howard; Tator, Charles H; Shoichet, Molly S

    2011-06-15

    Biomaterials are becoming increasingly popular for use in spinal cord repair, but few studies have investigated their long-term biocompatibility in central nervous system tissue. In this study, chitosan was compared with two commercial materials, degradable polyglycolide (vicryl and polyglactin 910) and nondegradable expanded poly(tetrafluoroethylene) (Gore-Tex and ePTFE), in terms of host tissue response and biodegradation in the rat spinal cord in two different spinal cord implantation models. In an uninjured model, implants were placed in the spinal cord intrathecal space for up to 6 months. At 1 month, vicryl implants elicited an elevated macrophage/microglia response compared to chitosan and Gore-Tex, which subsided in all groups by 6 months. Fibrous encapsulation was observed for all three materials. At 6 months, the in vivo degradation of vicryl was complete, while Gore-Tex showed no signs of degradation, as assessed by mass loss and SEM. Chitosan implants showed evidence of chain degradation at 6 months as demonstrated by differential hematoxylin and eosin staining; however, this did not result in mass loss. In the second model, implants were placed directly into the spinal cord for up to 12 months. This resulted in increased immune and inflammatory responses but did not alter degradation profiles. The same trends observed for the materials in the intrathecal space were mirrored in the spinal cord tissue. These results demonstrate that chitosan is a relatively inert biomaterial that does not elicit a chronic immune response and is suitable for long-term applications for repair of the spinal cord. PMID:21465644

  19. Electrochemistry and electrocatalysis with heme proteins in chitosan biopolymer films

    Microsoft Academic Search

    He Huang; Naifei Hu; Yonghuai Zeng; Gu Zhou

    2002-01-01

    Protein–chitosan (CS) films were made by casting a solution of proteins and CS on pyrolytic graphite electrodes. Myoglobin (Mb), hemoglobin (Hb), and horseradish peroxidase (HRP) incorporated in CS films gave a pair of stable, well-defined, and quasi-reversible cyclic voltammetric peaks at about ?0.33V vs saturated calomel electrode in pH 7 buffers, respectively, while catalase (Ct) in CS films showed a

  20. Zinc oxide-chitosan nanobiocomposite for urea sensor

    Microsoft Academic Search

    Pratima R. Solanki; Ajeet Kaushik; Anees A. Ansari; G. Sumana; B. D. Malhotra

    2008-01-01

    Zinc oxide (ZnO)-chitosan (CH) nanobiocomposite film onto indium-tin-oxide (ITO) coated glass has been used to immobilize urease (Urs) and glutamate dehydrogenase (GLDH) for urea detection. The presence of ZnO nanoparticles in CH results in its increased surface area and enhanced electron transfer kinetics. The Urs-GLDH\\/CH-ZnO\\/ITO bioelectrode characterized using electrochemical, Fourier transform infrared, and scanning electron microscopy studies exhibit linearity of

  1. Trimethylated chitosan as polymeric absorption enhancer for improved peroral delivery of peptide drugs

    Microsoft Academic Search

    S. M. van der Merwe; J. C. Verhoef; J. H. M. Verheijden; A. F. Kotzé; H. E. Junginger

    2004-01-01

    The absorption enhancing effects of chitosan and its derivatives have been intensively studied in recent years. It has been shown that these compounds are potent absorption enhancers. Chitosan is only soluble in acidic environments and is therefore incapable of enhancing absorption in the small intestine, the main absorption area in the gastrointestinal tract. Special emphasis has been placed on the

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

    PubMed Central

    Lisková, Jana; Ba?aková, Lucie; Skwarczy?ska, Agata L.; Musial, Olga; Bliznuk, Vitaliy; De Schamphelaere, Karel; Modrzejewska, Zofia; Douglas, Timothy E.L.

    2015-01-01

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

  3. Effect of different chitosan derivatives on in vitro scratch wound assay: a comparative study.

    PubMed

    Felice, Francesca; Zambito, Ylenia; Belardinelli, Ester; Fabiano, Angela; Santoni, Tatiana; Di Stefano, Rossella

    2015-05-01

    Different strategies have been developed to make the wound-healing process faster and less painful. Recently, numerous studies demonstrated the ability of chitosan to accelerate wound healing. Aim of the present study has been to evaluate the effect of different chitosan derivatives to improve wound healing process. Quaternary ammonium-chitosan conjugates with low or high molecular weight (MW) and their thiolated derivatives effect were studied on human skin fibroblasts in terms of viability and migration (scratch wound assay). Results were compared both with basal medium (untreated cells) and with a positive control (chitosan chlorhydrate). After 24h both high and low MW chitosan derivatives were non-toxic up to 10 ?g/ml. The concentration of 10 ?g/ml was used for wound healing experiments. High-MW quaternary ammonium-chitosan conjugates bearing thiol groups on their chains were more effective in promoting cell migration than the non-thiolated conjugates and the chitosan chlorhydrate. Moreover, they significantly improve wound healing process compared to untreated cells. According to the present in vitro preliminary results, high MW thiolated quaternary ammonium-chitosan conjugates can be considered good candidates for the management of wounds. PMID:25748846

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

    PubMed

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

    2014-04-01

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

  5. Development and Material Properties of Chitosan and Phosphomolybdic Acid-based Composites

    Microsoft Academic Search

    A. H. Bhat; Irshad-Ul-Haq Bhat; H. P. S. Abdul Khalil; R. K. Mishra; M. Datt; Ajit K. Banthia

    2011-01-01

    This work reports the development and characterization of chitosan\\/ phosphomolybdic acid-based composite membranes. The prepared composite membranes were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC), tensile strength test, and thermogravimetric analysis (TGA). FTIR spectroscopy indicated the proper molecular interactions between chitosan and PMA. XRD spectroscopy indicated the semi crystalline nature of the composite

  6. The potential of chitosan-based gels containing intervertebral disc cells for nucleus pulposus supplementation

    Microsoft Academic Search

    Peter Roughleya; Caroline Hoemannb; Eric DesRosiersc; Fackson Mwaled; John Antonioud; Mauro Alinie

    The suitability of chitosan-based hydrogels as scaffolds for the encapsulation of intervertebral disc (IVD) cells and the accumulation of a functional extracellular matrix mimicking that of the nucleus pulposus (NP) was investigated. The specific hypothesis under study was that the cationic chitosan would form an ideal environment in which large quantities of newly synthesized anionic proteoglycan could be entrapped. Indeed,

  7. Inactivation of salmonella on tomato stem scars by edible chitosan and organic Acid coatings.

    PubMed

    Jin, T; Gurtler, J B

    2012-08-01

    This study was conducted to investigate the efficacy of antimicrobial coatings for inactivation of Salmonella on the surface of tomato stem scars. Scars were inoculated with a four-strain cocktail of Salmonella (serovars Montevideo, Newport, Saintpaul, and Typhimurium) and coated with acid-chitosan solutions. The chitosan coating with three acids (3A plus chitosan), the chitosan coating with one acid, and the three-acid solution without chitosan reduced the populations of Salmonella by 6.0, 3.6, and 5.3 log CFU per stem scar, respectively. Addition of allyl isothiocyanate (10 ?l/ml) to the 3A plus chitosan coating did not significantly increase (P > 0.05) the antimicrobial efficacy. Although the populations of Salmonella in the controls (ca. 7.5 log CFU per stem scar) did not change significantly throughout the 14-day storage period at 10° C, Salmonella cells were reduced to undetectable levels (< 0.7 log CFU per stem scar) in the samples treated with 3A plus chitosan coating after two days of storage, and no growth was observed for the remaining storage period. Results from this study demonstrate that coatings of acid plus chitosan provide an alternative antimicrobial intervention for decontamination of tomatoes. PMID:22856559

  8. [Preparation and clinical application of polyvinyl alcohol/drug-loaded chitosan microsphere composite wound dressing].

    PubMed

    Zhang, Xiuju; Lin, Zhidan; Chen, Wenbin; Song, Ying; Li, Zhizhong

    2011-04-01

    In order to prepare and apply the polyvinyl alcohol/drug-loaded chitosan microspheres composite wound dressing, we first prepared chitosan microspheres by emulsion cross-linking method, and then added chitosan microspheres into the reactants during the acetalization of polyvinyl alcohol and formaldehyde. We further studied the morphology, water absorption, swelling degree, mechanical properties and in vitro release of the sponge with different amount of chitosan microspheres. The results showed that polyvinyl alcohol/drug-loaded chitosan composite sponge has porous structure with connectionism. Increasing the amount of chitosan microspheres would make the apertures smaller, so that the water absorption and the swelling of sponge decreased, but the tensile strength and compressive strength increased. With the increase of the amount of chitosan microspheres, the drug absorption of cefradine and the release rate increase, and the release time become longer. With the results of toxicity grade of 0 to 1, this type of composite sponge is non-toxic and meets the requirement of biocompatibility. The observation of rabbit nasal cavity after surgical operation suggested that polyvinyl acetal sponge modified with the chitosan has antiphlogistic, hemostatic and non-adherent characteristic, and can promote the healing and recovering of the nasalmucosa. After using this composite material, best growing surroundings for patients' granulation tissue were provided. Exposed bone and tendon were covered well with granulation tissue. PMID:21604506

  9. Surface-quaternized chitosan particles as an alternative and effective organic antibacterial material.

    PubMed

    Wiarachai, Oraphan; Thongchul, Nuttha; Kiatkamjornwong, Suda; Hoven, Voravee P

    2012-04-01

    Taking advantage of the large surface area that is covered with permanent positive charges of quaternary ammonium entities, this research aimed to develop environmentally friendly, organic antibacterial material from quaternized chitosan particles that may be applicable for biomedical devices, health and textile industries. The particles were formulated by ionic crosslinking of chitosan with tripolyphosphate followed by quaternization under heterogeneous conditions, via either direct methylation or reductive N-alkylation with a selected aldehyde followed by methylation. Sub-micron, spherical and positively charged quaternized chitosan particles were formed, as determined by (1)H NMR, FT-IR, PCS and TEM analysis. Antibacterial activity tests, performed by viable cell (colony) counts, suggested that all quaternized chitosan particles exhibited superior antibacterial activity against the model Gram-positive bacteria, Staphylococcus aureus, as compared to the native chitosan particles at neutral pH. Only some quaternized chitosan particles, especially those having a high charge density and bearing large alkyl substituent groups, were capable of suppressing the growth of the model Gram-negative bacteria, Escherichia coli. The inhibitory efficiency of the quaternized chitosan particles was quantified in terms of the minimum inhibitory concentration (MIC). Damaging impact of the quaternized chitosan particles on the bacteria was also qualitatively determined by microscopic observation of the bacterial morphology. PMID:22197736

  10. A validated 1H NMR method for the determination of the degree of deacetylation of chitosan

    Microsoft Academic Search

    M. Lavertu; Z. Xia; A. N. Serreqi; M. Berrada; A. Rodrigues; D. Wang; M. D. Buschmann; Ajay Gupta

    2003-01-01

    A method for the determination of the degree of deacetylation (DDA) of chitosan by 1H NMR spectroscopy has been formally validated. Chitosans with DDA ranging from 48 to 100% have been used for the validation. The method is found to be simple, rapid and more precise than other known techniques like IR or titration for %DDA measurements. The precision, ruggedness,

  11. Structural and antimicrobial properties of irradiated chitosan and its complexes with zinc

    NASA Astrophysics Data System (ADS)

    Khan, Azam; Mehmood, Shaukat; Shafiq, Muhammad; Yasin, Tariq; Akhter, Zareen; Ahmad, Shabir

    2013-10-01

    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?) of 220 kDa was exposed to gamma rays in dry, wet and solution forms. The chitosan-zinc complexes were prepared by varying the M? of chitosan and Zn content. Viscometeric analysis revealed a sharp decrease in the M? 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.

  12. Reporting degree of deacetylation values of chitosan: the influence of analytical methods

    Microsoft Academic Search

    Tanveer Ahmad Khan; Kok Khiang Peh

    Purpose. To investigate and compare the effect of three analytical methods, hydrogen bromide titri- metry (HBr titrimetry), infrared spectroscopy (IR spec- troscopy), and first derivative UV-spectrophotometry (FDUV-spectrophotometry) in the determination of degree of deacetylation (DD) of chitosan. Methods. Three different chitosan samples were selected for the DD quantification employing HBR titrimetry, IR spectroscopy with samples in the forms of KBr

  13. Comparing the efficiency of chitosan with chlorine for reducing Vibrio parahaemolyticus in shrimp

    Microsoft Academic Search

    S. Chaiyakosa; W. Charernjiratragul; K. Umsakul; V. Vuddhakul

    2007-01-01

    Thailand is one of the leading exporters of frozen shrimp to many countries. Chlorine is the decontaminating agent most frequently used in the frozen shrimp industries to kill potential pathogens. However, long time contact to chlorine causes severe respiratory tract damage. In this study, chitosan was compared to chlorine for reducing Vibrio parahaemolyticus. In vitro investigation, chitosan could reduce more

  14. Chitosan as a potential natural compound to control pre and postharvest diseases of horticultural commodities

    Microsoft Academic Search

    S. Bautista-Baños; A. N. Hernández-Lauzardo; M. G. Velázquez-del Valle; M. Hernández-López; E. Ait Barka; E. Bosquez-Molina; C. L. Wilson

    2006-01-01

    Chitosan, a given name to a deacetylated form of chitin, is a natural biodegradable compound derived from crustaceous shells such as crabs and shrimps, whose main attributes corresponds to its polycationic nature. Chitosan has been proven to control numerous pre and postharvest diseases on various horticultural commodities. It has been reported that both soil and foliar plant pathogens fungal, bacterial

  15. Removal of copper, chromium, and arsenic from CCA-treated wood onto chitin and chitosan

    Microsoft Academic Search

    S. Nami Kartal; Yuji Imamura

    2005-01-01

    Chitin and chitosan are naturally abundant biopolymers which are of interest to research concerning the sorption of metal ions since the amine and hydroxyl groups on their chemical structures act as chelation sites for metal ions. This study evaluates the removal of copper, chromium, and arsenic elements from chromated copper arsenate (CCA)-treated wood via biosorption by chitin and chitosan. Exposing

  16. In vitro assessment of N-(benzyl)chitosan derivatives against some plant pathogenic bacteria and fungi

    Microsoft Academic Search

    Entsar I. Rabea; Mohamed E. I. Badawy; Walter Steurbaut; Christian V. Stevens

    2009-01-01

    Plant pathogenic bacteria and fungi negatively affect a large number of important fruit and vegetables during the growing season and throughout postharvest storage. Therefore, the current study focuses on the preparation of N-(benzyl)chitosan derivatives as antimicrobial agents to control these microorganisms. Chitosan was reacted with a set of aromatic aldehydes by reductive amination involving formation of the corresponding imines, followed

  17. The potential role of free chitosan in bone trauma and bone cancer management.

    PubMed

    Tan, Mei L; Shao, Peng; Friedhuber, Anna M; van Moorst, Mallory; Elahy, Mina; Indumathy, Sivanjah; Dunstan, Dave E; Wei, Yongzhong; Dass, Crispin R

    2014-09-01

    Bone defects caused by fractures or cancer-mediated destruction are debilitating. Chitosan is commonly used in scaffold matrices for bone healing, but rarely as a free drug. We demonstrate that free chitosan promotes osteoblast proliferation and osteogenesis in mesenchymal stem cells, increases osteopontin and collagen I expression, and reduces osteoclastogenesis. Chitosan inhibits invasion of endothelial cells, downregulating uPA/R, MT1-MMP, cdc42 and Rac1. Better healing of bone fractures with greater trabecular bone formation was observed in mice treated with chitosan. Chitosan induces apoptosis in osteotropic prostate and breast cancer cells via caspase-2 and -3 activation, and reduces their establishment in bone. Chitosan is pro-apoptotic in osteosarcoma cells, but not their normal counterpart, osteoblasts, or chondrosarcoma cells. Systemic delivery of chitosan does not perturb angiogenesis, bone volume or instinctive behaviour in pregnant mice, but decreases foetal length and changes pancreatic secretory acini. With certain controls in place, chitosan could be useful for bone trauma management. PMID:24947230

  18. Comparison of chitosans with different molecular weights as possible wood preservatives

    Microsoft Academic Search

    Morten Eikenes; Gry Alfredsen; Bjørn Erik Christensen; Holger Militz; Halvor Solheim

    2005-01-01

    Fungi cause serious problems in wood utilization, and environmentally benign wood protection is required as an alternative to traditional chemicals. Chitosan has shown promising antimicrobial properties against several microorganisms. In this study, we present the characterization of and antifungal properties of a commercial chitosan formulation developed for impregnation of wood. A broad range of chemical and mycological methods were used

  19. Controlled release niosome embedded chitosan system: effect of crosslink mesh dimensions on drug release.

    PubMed

    Williams, Eva Christabel; Toomey, Ryan; Alcantar, Norma

    2012-12-01

    We report on a model chemotherapy drug delivery system comprising nonionic surfactant vesicles (niosomes) packaged within a temperature-sensitive chitosan network. This smart packaging, or package-within-a package system, provides two distinct advantages. First, the gel prevents circulation of the niosomes and maintains delivery in the vicinity of a tumor. Second, the chitosan network protects the niosomes against fluctuations in tonicity, which affects delivery rates. Tonicity is the sum of the concentrations of the solutes which have the capacity to exert an osmotic force across the membrane. All release rate experiments were conducted with 5,6-carboxyfluorescein, a fluorescent dye. Release rates were monitored from both bare niosomes alone and niosome-embedded, chitosan networks. It was observed that chitosan networks prolonged delivery from 100 h to 55 days in low ionic strength environment and pH conditions similar to a tumor site. The primary effect of chitosan is to add control on release time and dosage, and stabilize the niosomes through a high ionic strength surrounding that prevents uncontrolled bursting of the niosomes. Secondary factors include crosslink density of the chitosan network, molecular weight of the individual chitosan polymers, dye concentration within the niosomes, and the number density of niosomes packaged within the chitosan network. Each of these factors can be altered to fine-tune release rates. PMID:22733611

  20. Microwave-assisted facile synthesis of a new tri-block chitosan conjugate with improved mucoadhesion.

    PubMed

    Badhe, Ravindra V; Nanda, Rabindra K; Chejara, Dharmesh R; Choonara, Yahya E; Kumar, Pradeep; du Toit, Lisa C; Pillay, Viness

    2015-10-01

    A new chitosan-based tri-block conjugate, O-PEG-chitosan-N-cysteine was synthesized using microwave irradiation. For synthesis of this derivative, chitosan was modified to a PEG-chitosan conjugate followed by PEG-chitosan-cysteine using 6-O PEGylation and 2-N-thiolation, respectively. The synthesized derivative was characterized using various analytical techniques such as FT-IR and (1)H NMR spectroscopy. The conjugate was also analyzed for its biochemical, biodegradation and mucoadhesive properties. The modified chitosan conjugate exhibited improved mucoadhesion behavior (14.0h) with greater biodegradation compared to the parent polymer (6.3h). The in silico modeling corroborated with the in vitro study demonstrating a stable complex between mucin and O-PEG-chitosan-N-cysteine conjugate (?E=-60.100kcal/mol) compared to mucin and chitosan conjugate. The synthesis proposed herein, involves the use of microwave irradiation which causes a substantial reduction in the reaction time (approximately 2.30h) compared to conventional method (35h). PMID:26076619

  1. Biodegradation performance of a chitosan coated magnesium-zinc-tricalcium phosphate composite as an implant.

    PubMed

    Zhao, Jun; Chen, Liangjian; Yu, Kun; Chen, Chang; Dai, Yilong; Qiao, Xueyan; Yan, Yang

    2014-09-01

    A Mg-Zn-tricalcium phosphate composite with a chitosan coating was prepared in this investigation to study its biodegradation performance both in vitro and in vivo conditions. The in vitro test results show that the immersion corrosion rate, the pH values of the simulated body fluids and the released metal ion concentration of the chitosan coated composite are all lower than those of the uncoated composite. The in vitro cytotoxicity test shows that the chitosan coated specimens is safe for cellular applications. When the chitosan coated composite is tested in vivo, the concentration of metal ions from the composite observed in the venous blood of Zelanian rabbits is less than the uncoated composite specimens. The chitosan coating slows down the in vivo degradation of the composite after surgery. In vivo testing also indicates that the chitosan coated composite is harmless to important visceral organs, including the heart, kidneys, and liver of the rabbits. The new bone formation surrounding the chitosan coated composite implant shows that the composite improves the concrescence of the bone tissues. The chitosan coating is an effective corrosion resistant layer that reduces the hydrogen release of the implant composite, thereby decreasing the subcutaneous gas bubbles formed. PMID:25280845

  2. A novel use of chitosan as a hypocholesterolemic agent in rats1'2

    Microsoft Academic Search

    M. Sugano; T Fujikawa; Y Hiratsuji; K Nakashima; N. Fukuda; Y. Hasegawa

    1980-01-01

    A series of experiments with male rats clearly demonstrated the hypocholester- olemic activity of dietary chitosan. On feeding a high cholesterol diet for 20 days, addition of 2 to 5% chitosan resulted in a significant reduction, by 25 to 30%, of plasma cholesterol without influencing food intake and growth. The concentration of liver cholesterol and triglyceride also decreased significantly. Plasma,

  3. Calorimetric studies of the association of chitin and chitosan with sodium dodecyl sulfate

    Microsoft Academic Search

    Alexandre G. S Prado; Julio L Macedo; S??lvia C. L Dias; José A Dias

    2004-01-01

    The interaction of hydrophobic chitin and chitosan with sodium dodecyl sulfate (SDS) has been studied by titration calorimetry at 298.15K. The nature of interaction of the surfactant and biopolymers was followed by enthalpy interaction profiles. The mixing enthalpy curves were determined by mixing SDS solutions above their critical micelle concentration with chitin and chitosan suspensions in different concentrations. The Gibbs

  4. Antimicrobial activity of chitosan derivatives containing N-quaternized moieties in its backbone: a review.

    PubMed

    Martins, Alessandro F; Facchi, Suelen P; Follmann, Heveline D M; Pereira, Antonio G B; Rubira, Adley F; Muniz, Edvani C

    2014-01-01

    Chitosan, which is derived from a deacetylation reaction of chitin, has attractive antimicrobial activity. However, chitosan applications as a biocide are only effective in acidic medium due to its low solubility in neutral and basic conditions. Also, the positive charges carried by the protonated amine groups of chitosan (in acidic conditions) that are the driving force for its solubilization are also associated with its antimicrobial activity. Therefore, chemical modifications of chitosan are required to enhance its solubility and broaden the spectrum of its applications, including as biocide. Quaternization on the nitrogen atom of chitosan is the most used route to render water-soluble chitosan-derivatives, especially at physiological pH conditions. Recent reports in the literature demonstrate that such chitosan-derivatives present excellent antimicrobial activity due to permanent positive charge on nitrogen atoms side-bonded to the polymer backbone. This review presents some relevant work regarding the use of quaternized chitosan-derivatives obtained by different synthetic paths in applications as antimicrobial agents. PMID:25402643

  5. Antimicrobial Activity of Chitosan Derivatives Containing N-Quaternized Moieties in Its Backbone: A Review

    PubMed Central

    Martins, Alessandro F.; Facchi, Suelen P.; Follmann, Heveline D. M.; Pereira, Antonio G. B.; Rubira, Adley F.; Muniz, Edvani C.

    2014-01-01

    Chitosan, which is derived from a deacetylation reaction of chitin, has attractive antimicrobial activity. However, chitosan applications as a biocide are only effective in acidic medium due to its low solubility in neutral and basic conditions. Also, the positive charges carried by the protonated amine groups of chitosan (in acidic conditions) that are the driving force for its solubilization are also associated with its antimicrobial activity. Therefore, chemical modifications of chitosan are required to enhance its solubility and broaden the spectrum of its applications, including as biocide. Quaternization on the nitrogen atom of chitosan is the most used route to render water-soluble chitosan-derivatives, especially at physiological pH conditions. Recent reports in the literature demonstrate that such chitosan-derivatives present excellent antimicrobial activity due to permanent positive charge on nitrogen atoms side-bonded to the polymer backbone. This review presents some relevant work regarding the use of quaternized chitosan-derivatives obtained by different synthetic paths in applications as antimicrobial agents. PMID:25402643

  6. Chitosan phosphate: A new way for production of eco-friendly flame-retardant cotton textiles

    Microsoft Academic Search

    Khaled El-Tahlawy

    2008-01-01

    An increase in the health and environment legislation awareness pushed the textile manufacturers to develop their strategies to produce eco-friendly flame-retardant textiles with competitive cost. Chitosan is added during the phosphorylation process as a nitrogen source that has synergistic effect with phosphorus. Increasing the chitosan concentration from 0% to 2% enhances the flame retardancy of the treated cotton fabric against

  7. A novel kind of amphoteric composite nanofiltration membrane prepared from sulfated chitosan (SCS)

    Microsoft Academic Search

    Jing Miao; Guo-hua Chen; Cong-jie Gao

    2005-01-01

    Sulfated chitosan (SCS), a typical amphoteric polyelectrolyte, was prepared by a homogeneous method. A novel kind of amphoteric composite nanofiltration (NF) membrane was prepared by coating the aqueous solution of sulfated chitosan onto a PAN UF membrane, subsequently crosslinked with glutaraldehyde. The effects of the membrane preparation techniques and operating conditions on the rejection performance of the composite membranes were

  8. Modification of chitosan with monomethyl fumaric acid in an ionic liquid solution.

    PubMed

    Wang, Zhaodong; Zheng, Liuchun; Li, Chuncheng; Zhang, Dong; Xiao, Yaonan; Guan, Guohu; Zhu, Wenxiang

    2015-03-01

    Antibacterial and antioxidant monomethyl fumaric acid (MFA) was selected to modify chitosan, using aqueous solution of an ionic liquid as a homogeneous and green reaction media. The chemical structures of resulting polymers were systematically characterized by (1)H NMR, diffusion ordered spectroscopy, solid (13)C NMR and wide-angle X-ray diffraction. The results show that two kinds of MFA modified chitosan materials with totally different chemical structures have been synthesized. One product was a MF-chitosan salt composed of chitosan cation and MFA anion, which was obtained with the mediation of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide. The other one synthesized with the mediation of EDC was a MF-chitosan amide in which MFA and chitosan are covalently attached. Solubility of chitosan has been improved, and MF-chitosan salt can be readily dissolved in water. The antioxidant activity has been enhanced with the introduction of MFA, irrespective of the chemical structure. PMID:25498724

  9. Chitosan Augments Photodynamic Inactivation of Gram-Positive and Gram-Negative Bacteria?†

    PubMed Central

    Tsai, Tsuimin; Chien, Hsiung-Fei; Wang, Tze-Hsien; Huang, Ching-Tsan; Ker, Yaw-Bee; Chen, Chin-Tin

    2011-01-01

    Antimicrobial photodynamic inactivation (PDI) was shown to be a promising treatment modality for microbial infections. This study explores the effect of chitosan, a polycationic biopolymer, in increasing the PDI efficacy against Gram-positive bacteria, including Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, and methicillin-resistant S. aureus (MRSA), as well as the Gram-negative bacteria Pseudomonas aeruginosa and Acinetobacter baumannii. Chitosan at <0.1% was included in the antibacterial process either by coincubation with hematoporphyrin (Hp) and subjection to light exposure to induce the PDI effect or by addition after PDI and further incubation for 30 min. Under conditions in which Hp-PDI killed the microbe on a 2- to 4-log scale, treatment with chitosan at concentrations of as low as 0.025% for a further 30 min completely eradicated the bacteria (which were originally at ?108 CFU/ml). Similar results were also found with toluidine blue O (TBO)-mediated PDI in planktonic and biofilm cells. However, without PDI treatment, chitosan alone did not exert significant antimicrobial activity with 30 min of incubation, suggesting that the potentiated effect of chitosan worked after the bacterial damage induced by PDI. Further studies indicated that the potentiated PDI effect of chitosan was related to the level of PDI damage and the deacetylation level of the chitosan. These results indicate that the combination of PDI and chitosan is quite promising for eradicating microbial infections. PMID:21282440

  10. ENZYME-CATALYZED GEL-FORMATION OF GELATIN AND CHITOSAN. POTENTIAL FOR IN SITU APPLICATIONS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We compared the ability of two enzymes to catalyze the formation of gels from solutions of gelatin and chitosan. A microbial transglutaminase, currently under investigation for food applications, was observed to catalyze the formation of strong and permanent gels from gelatin solutions. Chitosan w...

  11. Development of thermosensitive hydrogels of chitosan, sodium and magnesium glycerophosphate for bone regeneration applications.

    PubMed

    Lisková, Jana; Ba?aková, Lucie; Skwarczy?ska, Agata L; Musial, Olga; Bliznuk, Vitaliy; De Schamphelaere, Karel; Modrzejewska, Zofia; Douglas, Timothy E L

    2015-01-01

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

  12. Environmentally friendly surface modification of silk fiber: Chitosan grafting and dyeing

    NASA Astrophysics Data System (ADS)

    Davarpanah, Saideh; Mahmoodi, Niyaz Mohammad; Arami, Mokhtar; Bahrami, Hajir; Mazaheri, Firoozmehr

    2009-01-01

    In this paper, the surface modification of silk fiber using anhydrides to graft the polysaccharide chitosan and dyeing ability of the grafted silk were studied. Silk fiber was degummed and acylated with two anhydrides, succinic anhydride (SA) and phthalic anhydride (PA), in different solvents (dimethyl sulfoxide (DMSO) and N, N-dimethyl formamide (DMF)). The effects of anhydrides, solvents, anhydride concentration, liquor ratio (L:R) and reaction time on acylation of silk were studied. The polysaccharide chitosan was grafted to the acylated silk fiber and dyed by acid dye (Acid Black NB.B). The effects of pH, chitosan concentration, and reaction time on chitosan grafting of acylated silk were investigated. The physical properties show sensible changes regardless of weight gain. Scanning electron microscopy (SEM) analysis showed the presence of foreign materials firmly attached to the surface of silk. FTIR spectroscopy provided evidence that chitosan was grafted onto the acylated silk through the formation of new covalent bonds. The dyeing of the chitosan grafted-acylated silk fiber indicated the higher dye ability in comparison to the acylated and degummed silk samples. The mechanism of chitosan grafting over degummed silk through anhydride linkage was proposed. The findings of this research support the potential production of new environmentally friendly textile fibers. It is worthwhile to mention that the grafted samples have antibacterial potential due to the antibacterial property of chitosan molecules.

  13. Properties of chitosan microencapsulated orange oil prepared by spray-drying and its stability to detergents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fragrance encapsulated in small particles of less than 20 µm diameter is preferred for use in textiles. In this study, aromatic orange oil was emulsified in a continuous phase of chitosan and spray-dried to produce microcapsules. The most effective combination of emulsifiers, ratio of chitosan to oi...

  14. Copper on Chitosan: A Recyclable Heterogeneous Catalyst for Azide-alkyne Cycloaddition Reactions in Water

    EPA Science Inventory

    Copper sulfate is immobilized over chitosan by simply stirring an aqueous suspension of chitosan in water with copper sulfate; the ensuing catalyst has been utilized for the azide-alkyne cycloaddition in aqueous media and it can be recycled and reused many time without loosing it...

  15. Effect of Drying Conditions on the Mechanical and Barrier Properties of Films Based on Chitosan

    Microsoft Academic Search

    I. Fernández-Pan; K. Ziani; R. Pedroza-Islas; J. I. Maté

    2010-01-01

    Films plasticized with glycerine were prepared using chitosan with two different molecular weights (Mw), 780 and 430 kDa. Films were obtained by drying at 80 and 40°C at 20 and 40% relative humidity (RH) in a climatic chamber. Drying kinetics were established by the measurement of the evolution of the actual temperatures of the film forming solutions. Chitosan Mw did not

  16. Solution casting of chitosan membranes for in vitro evaluation of bioactivity

    PubMed Central

    2013-01-01

    Background Considerable research is focusing on the surface modification of titanium implants for the treatment of orthopaedic tissue injuries to increase the success of orthopaedic fixations. Chitosan is one of the natural materials under investigation based on several favourable properties. Numerous techniques have been described for the preparation of chitosan membranes, including solution casting methods for the investigation of bioactivity before applying coatings onto potential titanium implants. Solution casting enables the easy in-house evaluation of chitosan membranes and allows for the selection of promising chitosan materials. Results We present a method for the standardized and easily applied preparation of chitosan membranes by solution casting. This protocol is suitable for chitosan materials spanning a wide degree of deacetylation, being derived from different chitin sources and chitosan derivatives with novel properties. We detail the preparation and quality control methods in order to prepare membranes with favourable bioactivity, sustaining cell attachment and proliferation for extended culture periods. Conclusions The possibilities associated with the use of chitosan in tissue engineering applications are far from being exhausted and numerous challenges remain prior to successful translation into the clinics. Based on our experience, we have developed simple in-house methods for quality control of homogeneous membrane casting and early prediction of successful experimental outcome. PMID:24192423

  17. Chitosan Enriched Three-Dimensional Matrix Reduces Inflammatory and Catabolic Mediators Production by Human Chondrocytes

    PubMed Central

    Oprenyeszk, Frederic; Sanchez, Christelle; Dubuc, Jean-Emile; Maquet, Véronique; Henrist, Catherine; Compère, Philippe; Henrotin, Yves

    2015-01-01

    This in vitro study investigated the metabolism of human osteoarthritic (OA) chondrocytes encapsulated in a spherical matrix enriched of chitosan. Human OA chondrocytes were encapsulated and cultured for 28 days either in chitosan-alginate beads or in alginate beads. The beads were formed by slowly passing dropwise either the chitosan 0.6%–alginate 1.2% or the alginate 1.2% solution through a syringe into a 102 mM CaCl2 solution. Beads were analyzed histologically after 28 days. Interleukin (IL)-6 and -8, prostaglandin (PG) E2, matrix metalloproteinases (MMPs), hyaluronan and aggrecan were quantified directly in the culture supernatant by specific ELISA and nitric oxide (NO) by using a colorimetric method based on the Griess reaction. Hematoxylin and eosin staining showed that chitosan was homogeneously distributed through the matrix and was in direct contact with chondrocytes. The production of IL-6, IL-8 and MMP-3 by chondrocytes significantly decreased in chitosan-alginate beads compared to alginate beads. PGE2 and NO decreased also significantly but only during the first three days of culture. Hyaluronan and aggrecan production tended to increase in chitosan-alginate beads after 28 days of culture. Chitosan-alginate beads reduced the production of inflammatory and catabolic mediators by OA chondrocytes and tended to stimulate the synthesis of cartilage matrix components. These particular effects indicate that chitosan-alginate beads are an interesting scaffold for chondrocytes encapsulation before transplantation to repair cartilage defects. PMID:26020773

  18. Shelf life and delivery enhancement of vitamin C using chitosan nanoparticles

    Microsoft Academic Search

    A. Alishahi; A. Mirvaghefi; M. R. Tehrani; H. Farahmand; S. A. Shojaosadati; F. A. Dorkoosh; Maher Z. Elsabee

    2011-01-01

    Chitosan with different molecular masses was reacted with sodium tripolyphosphate (STPP) to prepare different size nanoparticles, in which vitamin C was encapsulated. The effect of molecular weight (Mw) on nanoparticles efficiency, nanoparticles yield, size, and zeta potential was investigated in detail. Low Mw chitosan generated nanoparticles with better size, morphology, and delivery rate. In addition, the shelf life of encapsulated

  19. FUNCTIONALIZED CHITOSAN AND ITS USE IN PHARMACEUTICAL, BIOMEDICAL, AND BIOTECHNOLOGICAL RESEARCH

    Microsoft Academic Search

    Daniela Enescu; Camelia Elena Olteanu

    2008-01-01

    Hybrids of natural polymers with synthetic polymers are of great interest because of their application as biomedical and biodegradable materials. One of the natural polymers that has attracted much recent attention is chitosan, a polysaccharide obtained by alkaline deacetylation of chitin, exhibiting excellent biological properties such as biodegradability in the human body and immunological, antibacterial, and wound-healing activities. Chitosan has

  20. Surface Modification and Characterization of Chitosan Film Blended with Poly-L-Lysine

    Microsoft Academic Search

    Cheng Mingyu; Gong Kai; Li Jiamou; Gong Yandao; Zhao Nanming; Zhang Xiufang

    2004-01-01

    Biodegradable nerve guidance conduits (NGCs) represent a promising alternative to current clinical nerve repair procedures. Chitosan, a natural polysaccharide that has excellent biocompatibility and biodegradability, can be used as a nerve conduit material. The purpose of this work was to study the nerve cell affinity of chitosan modified by blending with different content of poly-L-lysine. PC12 cells culture was used

  1. Multilayers of cellulose derivatives and chitosan on nanofibrillated cellulose.

    PubMed

    Junka, Karoliina; Sundman, Ola; Salmi, Jani; Osterberg, Monika; Laine, Janne

    2014-08-01

    The aim of this work was to study the effect of solution conditions and polysaccharide structure on their Layer-by-Layer (LbL) deposition on nanofibrillated cellulose (NFC). Multilayer build-up of cellulose derivatives and chitosan on NFC model surfaces was studied using Quartz Crystal Microbalance with Dissipation (QCM-D) and Colloidal Probe Microscopy (CPM). The type of cationic polysaccharide was found to significantly affect the multilayer build-up and surface interactions. Cationic cellulose derivative quaternized hydroxyethyl cellulose ethoxylate (HECE) formed highly water-swollen layers with carboxymethyl cellulose (CMC), and the build-up was markedly influenced by both the ionic strength and pH. The ionic strength did not significantly influence the multilayer build-up of chitosan-CMC system, and adsorbed chitosan layers decreased the viscoelasticity of the system. Based on the results, it was also confirmed that electrostatic interaction is not the only driving force in case of the build-up of polysaccharide multilayers on nanofibrillated cellulose. PMID:24751244

  2. Alginate Hydrogels Coated with Chitosan for Wound Dressing

    PubMed Central

    Straccia, Maria Cristina; Gomez d’Ayala, Giovanna; Romano, Ida; Oliva, Adriana; Laurienzo, Paola

    2015-01-01

    In this work, a coating of chitosan onto alginate hydrogels was realized using the water-soluble hydrochloride form of chitosan (CH-Cl), with the dual purpose of imparting antibacterial activity and delaying the release of hydrophilic molecules from the alginate matrix. Alginate hydrogels with different calcium contents were prepared by the internal setting method and coated by immersion in a CH-Cl solution. Structural analysis by cryo-scanning electron microscopy was carried out to highlight morphological alterations due to the coating layer. Tests in vitro with human mesenchymal stromal cells (MSC) were assessed to check the absence of toxicity of CH-Cl. Swelling, stability in physiological solution and release characteristics using rhodamine B as the hydrophilic model drug were compared to those of relative uncoated hydrogels. Finally, antibacterial activity against Escherichia coli was tested. Results show that alginate hydrogels coated with chitosan hydrochloride described here can be proposed as a novel medicated dressing by associating intrinsic antimicrobial activity with improved sustained release characteristics. PMID:25969981

  3. Flocculation of algal cells by amphoteric chitosan-based flocculant.

    PubMed

    Dong, Changlong; Chen, Wei; Liu, Cheng

    2014-10-01

    A kind of amphoteric chitosan-based flocculant (quaternized carboxymethyl chitosan, denoted as QCMC) has been prepared. QCMC presented significant improvement of water solubility in the whole pH range. The effects of pH, dosage, temperature and original turbidity of algal water on the flocculation performance were investigated. The optimal dosages of QCMC at pH 5, 9 and 12 with original turbidity of 20NTU at 20°C were 0.1, 0.6 and 2.0mg/L, respectively, which were much less than that of chitosan, PAM, Al2(SO4)3 and FeCl3. The floc properties during grow, breakage and regrow period were also evaluated at different pH values in terms of floc size, strength and density. It was demonstrated that QCMC produced larger, stronger and denser flocs than Al2(SO4)3. There is every indication that QCMC is more suitable for algal harvesting than other traditional coagulants or flocculants. PMID:25146316

  4. Thermosensitive macroporous cryogels functionalized with bioactive chitosan/bemiparin nanoparticles.

    PubMed

    Peniche, Hazel; Reyes-Ortega, Felisa; Aguilar, María R; Rodríguez, Gema; Abradelo, Cristina; García-Fernández, Luis; Peniche, Carlos; San Román, Julio

    2013-11-01

    Thermosensitive macroporous scaffolds of poly(N-isopropylacrylamide) (polyNIPA) loaded with chitosan/bemiparin nanoparticles are prepared by the free radical polymerization in cryogenic conditions. Chitosan/bemiparin nanoparticles of 102?±?6.5?nm diameter are prepared by complex coacervation and loaded into polyNIPA cryogels. SEM image reveal the highly porous structure of cryogels and the integration of nanoparticles into the macroporous system. Volume phase transition temperature (VPT) and total freezing water content of cryogels are established by differential scanning calorimetry, and their porosity is determined by image-NMR. Swelling of cryogels (above and below the VPT) is highly dependent on nanoparticles concentration. In vitro release profile of bemiparin from cryogel is highly modulated by the presence of chitosan. Bemiparin released from nanoparticles preserves its biological activity, as shown by the BaF32 cell proliferation assay. Cryogels are not cytotoxic for the human fibroblast cells and present excellent properties for application on tissue engineering and controlled release of heparin. PMID:23956200

  5. Laser photolysis of fluorone dyes in a chitosan matrix

    SciTech Connect

    Slyusareva, E A; Sizykh, A G; Gerasimova, M A; Slabko, V V; Myslivets, S A

    2012-08-31

    Kinetics of laser-induced photobleaching of fluorone dyes (fluorescein, dibromofluorescein, eosin Y, erythrosin B, Rose Bengal) is studied in a chitosan matrix. For all dyes the bleaching kinetics at the intensities of laser radiation 0.7 - 11.9 W cm{sup -2} demonstrates quasi-monomolecular behaviour. The results are analysed using a kinetic model, based on the four-level (S{sub 0}, S{sub 1}, T{sub 1}, T{sub n}) scheme of the dye with chemically active triplet states taken into account. It is shown that the rate constants of the chemical reaction involving higher triplet states in the dyes studied amount to (3.9 - 18.6) Multiplication-Sign 10{sup 6} s{sup -1} and exceed the analogous values for the reaction involving the first lower triplet states by nine orders of magnitude. The rate of reaction involving the first triplet states appeared to be higher by one - two orders of magnitude than that in the case of higher triplet states involved because of low population of the latter. The possible mechanism of dye bleaching with participation of chitosan that consists in reduction of the dye to the leuco form by transfer of hydrogen from the chitosan matrix is discussed. (interaction of laser radiation with matter. laser plasmas)

  6. Bioavailability enhancement of verapamil HCl via intranasal chitosan microspheres.

    PubMed

    Abdel Mouez, Mamdouh; Zaki, Noha M; Mansour, Samar; Geneidi, Ahmed S

    2014-01-23

    Chitosan microspheres are potential drug carriers for maximizing nasal residence time, circumventing rapid mucociliary clearance and enhancing nasal absorption. The aim of the present study was to develop and characterize chitosan mucoadhesive microspheres of verapamil hydrochloride (VRP) for intranasal delivery as an alternative to oral VRP which suffers low bioavailability (20%) due to extensive first pass effect. The microspheres were produced using a spray-drying and precipitation techniques and characterized for morphology (scanning electron microscopy), particle size (laser diffraction method), drug entrapment efficiency, thermal behavior (differential scanning calorimetry) and crystallinity (X-ray diffractometric studies) as well as in vitro drug release. Bioavailability of nasal VRP microspheres was studied in rabbits and the results were compared to those obtained after nasal, oral and intravenous administration of VRP solution. Results demonstrated that the microspheres were spherical with size 21-53 ?m suitable for nasal deposition. The spray-drying technique was superior over precipitation technique in providing higher VRP entrapment efficiency and smaller burst release followed by a more sustained one over 6h. The bioavailability study demonstrated that the nasal microspheres exhibited a significantly higher bioavailability (58.6%) than nasal solution of VRP (47.8%) and oral VRP solution (13%). In conclusion, the chitosan-based nasal VRP microspheres are promising for enhancing VRP bioavailability by increasing the nasal residence time and avoiding the first-pass metabolism of the drug substance. PMID:23999035

  7. Chitosan microspheres of aceclofenac: in vitro and in vivo evaluation.

    PubMed

    Nagda, Chirag; Chotai, Narendra; Patel, Sandip; Nagda, Dhruti; Patel, Upendra; Soni, Tejal

    2010-01-01

    The objective of this investigation was to achieve controlled drug release of Aceclofenac (ACE) microspheres and to minimize local side-effects in the gastrointestinal tract (GIT). Sustained release chitosan microspheres containing ACE were prepared using double-emulsion solvent evaporation method (O/W/O). Chitosan microspheres were prepared by varying drug to polymer ratio (1:3, 1:4, 1:5 and 1:6). Microspheres were characterized for morphology, swelling behavior, mucoadhesive properties, FTIR and DSC study, drug loading efficiency, in vitro release, release kinetics, and in vivo study was performed on rat model. ACE-loaded microspheres were successfully prepared having production yield, 57-70% w/w. Drug encapsulation efficiency was ranging from 53-72% w/w, Scanning electron microscopy (SEM) revealed particle size of microspheres was between 39 and 55 mum. FTIR spectra and DSC thermograms demonstrated no interaction between drug and polymer. The in vitro release profiles of drug from chitosan microspheres showed sustained-release pattern of the drug in phosphate buffer, pH 6.8. In vitro release data showed correlation (r2 > 0.98), good fit with Higuchi/Korsmeyer-Peppas models, and exhibited Fickian diffusion. ACE microspheres demonstrated controlled delivery of aceclofenac and apparently, no G.I.T. erosion was noticed. PMID:20735299

  8. Preparation and characterization of nano chitosan for treatment wastewaters.

    PubMed

    Sivakami, M S; Gomathi, Thandapani; Venkatesan, Jayachandran; Jeong, Hee-Seok; Kim, Se-Kwon; Sudha, P N

    2013-06-01

    Chitosan nanorod with minimum particle size of <100 nm was prepared by crosslinking low molecular weight chitosan with polyanion sodium tripolyphosphate and physicochemically characterized (FT-IR, XRD, SEM, AFM, TGA and DSC) for waste water treatment. Its sorption capacity and sorption isotherms for chromium (Cr) were studied. The effect of initial concentration of Cr ions, sorbent amount, agitation period and pH of solution that influence sorption capacity were also investigated. It was found that nanochitosan in the solid state was rod shaped which could sorb Cr (VI) to Cr (III) ions effectively. Based on the Langmuir, the Freundlich and the Temkin sorption isotherms, the sorption capacity of chitosan nanoparticles is very high and the adsorbent favors multilayer adsorption. The kinetics studies show that the adsorption follows the pseudo-second-order kinetics, which infers the transformation of Cr (VI) to Cr (III). From the results it was concluded that nanochitosan is an excellent material as a biosorbent for Cr removal from water. PMID:23500442

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

    PubMed

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

    2015-09-01

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

  10. Chitosan/arginine-chitosan polymer blends for assembly of nanofibrous membranes for wound regeneration.

    PubMed

    Antunes, B P; Moreira, A F; Gaspar, V M; Correia, I J

    2015-10-01

    Frequently, skin is subjected to damaging events, such as deep cuts, burns or ulcers, which may compromise the integrity of this organ. To overcome such lesions, different strategies have been employed. Among them, wound dressings aimed to re-establish skin native properties and decreased patient pain have been pursued for a long time. Herein, an electrospun membrane comprised by deacetylated/arginine modified chitosan (CH-A) was produced to be used as a wound dressing. The obtained results showed that the membrane has a highly hydrophilic and porous three-dimensional nanofibrous network similar to that found in human native extracellular matrix. In vitro data indicate that human fibroblasts adhere and proliferate in contact with membranes, thus corroborating their biocompatibility. This nanofiber-based biomaterial also demonstrated bactericidal activity for two bacterial strains. In vivo application of CH-A nanofibers in full thickness wounds resulted in an improved tissue regeneration and faster wound closure, when compared to non-modified membranes. Such findings support the suitability of using this membrane as a wound dressing in a near future. PMID:26076606

  11. Investigation of Chitosan for Decorporation of 60Co in the Rat

    SciTech Connect

    Levitskaia, Tatiana G.; Creim, Jeffrey A.; Curry, Terry L.; Luders, Teresa; Morris, James E.; Sinkov, Sergey I.; Woodstock, Angela D.; Thrall, Karla D.

    2009-08-01

    Purpose: The reported investigation is a part of our on-going research aimed at identifying effective in vivo non-toxic decorporation agents and developing new therapies to treat internal contamination with radionuclides. The non-toxic nature of chitosan makes it an especially attractive candidate for unsupervised treatment of the general population in case of radiological/nuclear emergency. In this study, chemically unmodified water-soluble chitosan oligosaccharide of low molecular weight was tested for decorporation of cobalt-60 (Co-60) using a rodent model. Methods: Affinity of chitosan oligosaccharide for Co(II) was tested in vitro under conditions of physiological pH range and ionic strength using combined spectrophotometric and potentiometric titration techniques. Fisher F344 rat model was used for in vivo studies. To evaluate effect of chitosan on ingested Co-60, animals received single oral dose of Co-60 chloride (7 – 13.2 kBq per animal) followed by oral administration of chitosan material (288 – 366 mg per kg body weight); chitosan dosing was repeated in 24 hours. Chitosan was also tested for removal of internalized Co-60. In this study, Co-60 single intravenous injection (7 – 8 kBq per animal) was followed by repetitive oral (300 mg per kg body weight) or intravenous (195 mg per kg body weight) administration of the chitosan material once daily for 5 days. Control animal groups received a single dose of Co-60 without chelator treatment. Excreta was collected daily. Tissues were collected postmortem and analyzed for radioactivity by gamma counting technique. Results: In vitro experiments confirmed binding of Co(II) by chitosan oligosaccharide, formation of mixed cobalt-chitosan-hydroxide complex species was proposed, and stability constants was calculated. Control in vivo studies indicated that about 71% of ingested Co-60 was excreted in two days predominantly through the gastrointestinal tract. For intravenously administered Co-60, urinal excretion was dominant and was found to decrease linearly with time. The oral administration of chitosan appeared to reduce absorption of ingested Co-60; radioactivity in liver and kidney was reduced by over 50%. Intravenously administered chitosan reduced Co-60 levels (after intravenous dosing) in multiple tissues by 15 – 30 %. Decorporation efficacy of oral chitosan was weak. Conclusion: Commercial chemically-unmodified chitosan oligosaccharide exhibited strong potential for the treatment of oral or systemic cobalt exposure. Further studies are warranted to evaluate the dosing regiment.

  12. Development of a Chitosan-Based Biofoam: Application to the Processing of a Porous Ceramic Material

    PubMed Central

    Mathias, Jean-Denis; Tessier-Doyen, Nicolas; Michaud, Philippe

    2011-01-01

    Developing biofoams constitutes a challenging issue for several applications. The present study focuses on the development of a chitosan-based biofoam. Solutions of chitosan in acetic acid were dried under vacuum to generate foams with high-order structures. Chitosan concentration influenced significantly the morphology of developed porosity and the organization of pores in the material. Physico-chemical characterizations were performed to investigate the effects of chitosan concentration on density and thermal conductivity of foams. Even if chitosan-based biofoams exhibit interesting insulating properties (typically around 0.06 W·m?1·K?1), it has been shown that their durabilities are limited when submitted to a wet media. So, a way of application consists to elaborate a ceramic material with open porosity from a slurry prepared with an organic solvent infiltrating the porous network of the foam. PMID:21541051

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

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

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

  14. Antimicrobial, mechanical, and barrier properties of cassava starch-chitosan films incorporated with oregano essential oil.

    PubMed

    Pelissari, Franciele M; Grossmann, Maria V E; Yamashita, Fabio; Pineda, Edgardo Alfonso G

    2009-08-26

    The physicochemical and antimicrobial properties of starch-chitosan films incorporated with oregano essential oil (OEO) have been investigated. The antimicrobial effects of starch-chitosan-OEO films against Bacillus cereus, Escherichia coli, Salmonella enteritidis, and Staphylococcus aureus were determined by the disk inhibition zone method. The film mechanical properties, water vapor permeability (WVP), Fourier transform infrared spectra (FTIR), and thermograms (TGA) were also determined. Films added with OEO effectively inhibited the four microorganisms tested and demonstrated improved barrier properties. The presence of OEO in starch-chitosan films led to the formation of more flexible films. Chitosan was not effective against the tested organisms, but it decreased film rigidity and WVP. TGA analysis demonstrated that the addition of chitosan and OEO did not affect the thermal stability of the films. PMID:19627142

  15. An innovative bioremediation strategy using a bacterial consortium entrapped in chitosan beads.

    PubMed

    Angelim, Alysson Lira; Costa, Samantha Pinheiro; Farias, Bárbara Cibelle Soares; Aquino, Lyanderson Freitas; Melo, Vânia Maria Maciel

    2013-09-30

    This aim of this work was to develop a bioremediation strategy for oil-contaminated mangrove sediments using chitosan beads containing an immobilised hydrocarbonoclastic bacterial consortium. The consortium composed of 17 isolates was obtained from an enrichment culture. The isolates were identified by 16S rDNA sequencing, which revealed 12 different genera. Thirteen isolates showed resistance to chitosan and were thus able to be trapped in chitosan beads for microcosm evaluation. The data revealed that entrapped consortium grew in the microcosms until day 15, which is when the beads disintegrated and released their biomass into the sediments. Bacterial bioaugmentation within the sediments was confirmed by cell counts; additionally, the dynamics of the bacterial populations were analysed through denaturing gradient gel electrophoresis. The chitosan showed a prebiotic effect on the autochthonous bacterial communities. Therefore, chitosan beads containing selected immobilised bacteria attain two bioremediation purposes, bioaugmentation and biostimulation, and thus represent an emergent approach. PMID:23659866

  16. Catechol-functionalized chitosan/pluronic hydrogels for tissue adhesives and hemostatic materials.

    PubMed

    Ryu, Ji Hyun; Lee, Yuhan; Kong, Won Ho; Kim, Taek Gyoung; Park, Tae Gwan; Lee, Haeshin

    2011-07-11

    Bioinspired from adhesion behaviors of mussels, injectable and thermosensitive chitosan/Pluronic composite hydrogels were synthesized for tissue adhesives and hemostatic materials. Chitosan conjugated with multiple catechol groups in the backbone was cross-linked with terminally thiolated Pluronic F-127 triblock copolymer to produce temperature-sensitive and adhesive sol-gel transition hydrogels. A blend mixture of the catechol-conjugated chitosan and the thiolated Pluronic F-127 was a viscous solution state at room temperature but became a cross-linked gel state with instantaneous solidification at the body temperature and physiological pH. The adhesive chitosan/Pluronic injectable hydrogels with remnant catechol groups showed strong adhesiveness to soft tissues and mucous layers and also demonstrated superior hemostatic properties. These chitosan/Pluronic hydrogels are expected to be usefully exploited for injectable drug delivery depots, tissue engineering hydrogels, tissue adhesives, and antibleeding materials. PMID:21599012

  17. Facile Synthesis of Silver Nanoparticles Under {gamma}-Irradiation: Effect of Chitosan Concentration

    SciTech Connect

    Huang, N. M.; Radiman, S.; Ahmad, A.; Idris, H. [Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi (Malaysia); Lim, H. N. [Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Khiew, P. S.; Chiu, W. S.; Tan, T. K. [Faculty of Engineering and Computer Science, Nottingham University, 43500 Semenyih (Malaysia)

    2009-06-01

    In the present study, a biopolymer, low molecular weight chitosan had been utilized as a 'green' stabilizing agent for the synthesis of silver nanoparticles under {gamma}-irradiation. The as-synthesized silver nanoparticles have particle diameters in the range of 5 nm-30 nm depending on the percentage of chitosan used (0.1 wt%, 0.5 wt%, 1.0 wt% and 2.0 wt%). It was found that the yield of the silver nanoparticles was in accordance with the concentration of chitosan presence in the solution due to the reduction by the chitosan radical during irradiation. The highly stable chitosan encapsulated silver nanoparticles were characterized using transmission electron microscopy (TEM), UV-Visible spectrophotometer (UV-VIS) and X-ray diffraction spectroscopy (XRD)

  18. Density functional theory studies of Pb (II) interaction with chitosan and its derivatives.

    PubMed

    Hassan, Basila; Muraleedharan, K; Abdul Mujeeb, V M

    2015-03-01

    Density functional theory (DFT) studies of Pb (II) ions interaction with biopolymer chitosan and its derivatives are presented. Schiff bases and N-alkylated/arylated derivatives of chitosan were characterized as adsorbents of lead ions and are studied at monomer level. Natural bond orbital (NBO) analysis was carried out for chitosan and derivatives to understand the donor-acceptor interactions. Molecular electrostatic potential (MEP) maps of the adsorbents were plotted with color code. Global reactivity parameters of adsorbents were calculated on the basis of frontier molecular orbital (FMO) energies. Structure of complexes formed between chitosan and derivatives with Pb (II) ion were examined at B3LYP/LanL2DZ level of DFT. The stability of the complexes are discussed based on the values of Eads. We observed that the N-reduced pyridine carboxaldehyde derivative of chitosan (RPC) forms more stable complex with Pb (II) ions than with other derivatves. PMID:25583020

  19. Production of chitosan-based non-woven membranes using the electrospinning process

    NASA Astrophysics Data System (ADS)

    Pakravan Lonbani, Mehdi

    Chitosan is a modified natural polymer mainly produced from chitin, one of the most abundant organic materials in the world. Highly porous chitosan mats present the specific physicochemical properties of the base material and also benefit from the physical characteristics of nanoporous membranes. Electrospinning is a novel technique developed long time ago and revisited recently that can generate polymeric fibers with nanometric size. The ultimate purpose of this work is to fabricate microporous non-woven chitosan membranes for wound healing dressings and heavy metal ion removal from drinking water. In this dissertation, two approaches have been utilized to prepare chitosan-based nanofibers; blending and co-axial electrospinning of chitosan solution with a readily electrospinnable solution, i.e. an aqueous solution of polyethylene oxide (PEO). Consequently, understanding the phase behavior and miscibility of aqueous acidic solutions of chitosan and PEO and their blends is of crucial importance, as any phase separation occurring during the electrospinning process greatly changes the morphology and physico-mechanical properties of the final products. First we employed the rheological approach on a well-known aqueous PEO solution to develop the experimental protocol. By comparing these critical points with that obtained from other experimental techniques, we showed that rheological measurements can sensitively detect early stages of phase separation. Subsequently the method was applied to 50 wt% aqueous acetic acid solutions of PEO, chitosan and their blends at different ratios. These solutions showed a lower critical solution temperature (LCST) phase diagram that is attributed to the existence of hydrogen bonds between active groups on chitosan and PEO backbone and the solvent. Critical decomposition temperatures for binodal and spinodal points were estimated from isochronal temperature sweep experiments. The obtained binodal temperatures confirmed that chitosan/PEO solutions are miscible and stable at moderate temperatures and phase separate at higher temperatures of 60-75 °C. Then, we intended to obtain a thorough understanding of chitosan/PEO solution properties that lead to a successful electrospinning process, i.e. continuous and stable, and which produces defect free uniform beadless nanofibers. The effect of blend composition and acetic acid concentration on properties such as surface tension and conductivity and, ultimately, on electrospinnability were investigated. A highly deacetylated chitosan (DDA=97.5 %) in 50% acetic acid was used, which is the maximum deacetylated chitosan grade that has been reported for the preparation of electrospun chitosan-based nanofibers. The rheological characteristics of the chitosan/PEO solutions as a controlling parameter in the electrospinning process were examined and their relationships to electrospinnability presented. As we showed that chitosan/PEO solutions are miscible and stable at moderate temperatures, a modified electrospinning set up to electrospin at temperatures of 25-70 °C was designed to achieve content as high as 90 wt% of chitosan in beadless chitosan/PEO nanofibers of 60-80 nm in diameter. It was also found that increasing chitosan/PEO ratio from 50/50 to 90/10 led to a remarkable diameter reduction from 123 to 63 nm at room temperature. Additionally, we found that moderate process temperatures help to stabilize the electrospinning process of these solutions and produce beadless nanofibers. However, at higher temperatures, the electrospun jet became unstable and beaded fiber morphology was obtained. This phenomena occurs closely at the temperature range of phase separation, previously determined by rheology studies. Therefore, temperature-induced phase separation of these solutions is considered as the reason for that observation. On the other hand, an FTIR study at room temperature on cast films and nanofibers of chitosan/PEO blends at room temperature showed the presence of hydrogen bonding interactions between chitosan and PEO that could be an another indic

  20. Chitosan improves the biological performance of soy-based biomaterials.

    PubMed

    Santos, Tírcia C; Marques, Alexandra P; Silva, Simone S; Oliveira, Joaquim M; Mano, João F; Castro, António G; van Griensven, Martijn; Reis, Rui L

    2010-09-01

    Soybean protein has been proposed for distinct applications within nutritional, pharmaceutical, and cosmetic industries among others. More recently, soy-based biomaterials have also demonstrated promising properties for biomedical applications. However, although many reports within other fields exist, the inflammatory/immunogenic potential of those materials is still poorly understood and therefore can hardly be controlled. On the contrary, chitosan (Cht) has been well explored in the biomedical field, either by itself or combined with synthetic or other natural-based polymers. Therefore, the combination of chitosan with soybean protein is foreseen as a suitable approach to control the biological behavior of soy-based biomaterials. Under this context this work was designed to try to understand the influence of chitosan in the host response elicited by soy-based biomaterials. Soybean protein isolate powder (SI-P) and Cht powder (Cht-P) were injected as suspension into the intraperitoneal cavity of rats. SI-P induced the recruitment of higher numbers of leukocytes compared to the Cht-P during the entire observation period. In this sense, SI-P elicited a considerable reaction from the host comparing to the Cht-P, which elicited leukocyte recruitment similar to the negative control. After subcutaneous implantation of the soybean and denatured membranes, (SI-M and dSI-M) a severe host inflammatory reaction was observed. Conversely, Cht/soy-based membranes (Cht/soy-based membranes) showed the induction of a normal host response after subcutaneous implantation in rats, which allowed concluding that the addition of chitosan to the soy-based membranes improved their in vivo performance. Thus, the presented results assert the improvement of the host response, considering inflammatory cells recruitment, and overall inflammatory reaction, when chitosan is combined to soybean. Together with previous results that reported their promising physicochemical characteristics and their inability to activate human polymorphonuclear neutrophils in vitro, the herein presented conclusions reinforce the usefulness of the Cht/soy-based membranes and justify the pursue for a specific application within the biomedical field. PMID:20486796

  1. Synthesis and structure-activity relationship of N-(cinnamyl) chitosan analogs as antimicrobial agents.

    PubMed

    Badawy, Mohamed E I; Rabea, Entsar I

    2013-06-01

    The current study focuses on the preparation of new N-(cinnamyl) chitosan derivatives as antimicrobial agents against nine types of crop-threatening pathogens. Chitosan was reacted with a set of aromatic cinnamaldehyde analogs by reductive amination involving formation of the corresponding imines, followed by reduction with sodium borohydride to produce N-(cinnamyl) chitosan derivatives. The structural characterization was confirmed by (1)H and (13)C NMR spectroscopy and the degrees of substitution ranged from 0.08 to 0.28. The antibacterial activity was evaluated in vitro by minimum inhibitory concentration (MIC) against Agrobacterium tumefaciens and Erwinia carotovora. A higher inhibition activity was obtained by N-(?-methylcinnamyl) chitosan with MIC 1275 and 1025 mg/L against A. tumefaciens and E. carotovora, respectively followed by N-(o-methoxycinnamyl) chitosan (MIC=1925 and 1550 mg/L, respectively). The antifungal assessment was evaluated in vitro by mycelial radial growth technique against Alternaria alternata, Botrytis cinerea, Botryodiplodia theobromae, Fusarium oxysporum, Fusarium solani, Pythium debaryanum and Phytophthora infestans. N-(o-methoxycinnamyl) chitosan showed the highest antifungal activity among the tested compounds against the airborne fungi A. alternata, B. cinerea, Bd. theobromae and Ph. infestans with EC?? of 672, 796, 980 and 636 mg/L, respectively. However, N-(p-N-dimethylaminocinnamyl) chitosan was the most active against the soil born fungi F. oxysporum, F. solani and P. debaryanum (EC50=411, 566 and 404 mg/L, respectively). On the other hand, the chitosan derivatives caused significant reduction in spore germination of A. alternata, B. cinerea, F. oxysporum and F. solani compared to chitosan and the reduction in spore germination was higher than that of the mycelia inhibition. The synthesis and characterization of new chitosan derivatives are ongoing in our laboratory aiming to obtain derivatives with higher antimicrobial activities and used as safe alternatives to harmful microbicides. PMID:23511055

  2. Antimicrobial action of hydrolyzed chitosan against spoilage yeasts and lactic acid bacteria of fermented vegetables.

    PubMed

    Savard, Tony; Beaulieu, Carole; Boucher, Isabelle; Champagne, Claude P

    2002-05-01

    The antimicrobial properties of various chitosan-lactate polymers (ranging from 0.5 to 1.2 MDa in molecular weight) against two yeasts isolated from fermented vegetables and against three lactic acid bacteria from a mixed starter for sauerkraut on methylene blue agar (MBA) and in vegetable juice medium (VJM) were investigated. Chitosan-lactate reduced the growth of all microorganisms in solid (MBA) as well as in liquid (VJM) medium. In MBA, a concentration of 5 g/liter was needed to inhibit the growth of Saccharomyces bayanus, while 1 g/liter was sufficient to inhibit the growth of Saccharomyces unisporus. Lactic acid bacteria were also inhibited in this range of concentrations. The low-molecular-weight chitosan-lactate DP3 (0.5 kDa) was most efficient in solid medium (MBA), and inhibitory activities decreased with increasing hydrolysate lengths. In liquid medium (VJM), 0.5 g of chitosan-lactate per liter reduced the growth rates for both yeasts, but 10 g/liter was insufficient to prevent yeast growth. Intermediate-molecular-weight chitosan-lactate (5 kDa) was more efficient than chitosan of low molecular weight. Native chitosan (1.2 MDa) showed no inhibition in either medium. Microscopic examination of S. unisporus Y-42 after treatment with chitosan-lactate DP25 showed agglutination of a refractive substance on the entire cell wall, suggesting an interaction between chitosan and the cell wall. When chitosanase was added to the culture media containing chitosan-lactate, refractive substances could not be observed. PMID:12030295

  3. The effect of radiation on the thermal properties of chitosan/mimosa tenuiflora and chitosan/mimosa tenuiflora/multiwalled carbon nanotubes (MWCNT) composites for bone tissue engineering

    NASA Astrophysics Data System (ADS)

    Martel-Estrada, S. A.; Santos-Rodríguez, E.; Olivas-Armendáriz, I.; Cruz-Zaragoza, E.; Martínez-Pérez, C. A.

    2014-07-01

    The purpose of this study is to examine the effect of gamma radiation and UV radiation on the microstructure, chemical structure and thermal stability of Chitosan/Mimosa Tenuiflora and Chitosan/Mimosa Tenuiflora/MWCNT composites scaffolds produced by thermally induced phase separation. The composites were irradiated and observed to undergo radiation-induced degradation through chain scission. Morphology, thermal properties and effects on chemical and semi-crystalline structures were obtained by scanning electronic microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), FT-IR analysis and X-ray Diffraction. A relationship between radiation type and the thermal stability of the composites, were also established. This relationship allows a more accurate and precise control of the life span of Chitosan/Mimosa Tenuiflora and Chitosan/Mimosa Tenuiflora/MWCNT composites through the use of radiation in materials for use in tissue engineering.

  4. Preparation and characterization of biofunctionalized chitosan/Fe3O4 magnetic nanoparticles for application in liver magnetic resonance imaging

    NASA Astrophysics Data System (ADS)

    Song, Xiaoli; Luo, Xiadan; Zhang, Qingqing; Zhu, Aiping; Ji, Lijun; Yan, Caifeng

    2015-08-01

    Biofunctionalized chitosan@Fe3O4 nanoparticles are synthesized by combining Fe3O4 and CS chemically modified with PEG and lactobionic acid in one step. The biofunctionalized nanoparticles are characterized by TEM, X-ray, DLS, zeta-potential and magnetic measurements. The in vitro and in vivo behaviors of the biofunctionalized nanoparticles, especially, the cytotoxicity, the protein resistance, metabolism and iron toxicity are assessed. The functional groups, PEG enable the nanoparticles more biocompatible and the lactobionic acid groups enable liver targeting. The potential applications of the nanoparticles in liver magnetic resonance imaging are confirmed. The results demonstrated that the nanoparticles are suspension stability, non-cytotoxicity, non-tissue toxicity and sensitive in liver magnetic resonance imaging, representing potential tools for applications in the biomedical field.

  5. Packaging-specific influence of chitosan on color stability and lipid oxidation in refrigerated ground beef.

    PubMed

    Suman, S P; Mancini, R A; Joseph, P; Ramanathan, R; Konda, M K R; Dady, G; Yin, S

    2010-12-01

    We examined the influence of chitosan on lipid oxidation and color stability of ground beef stored in different modified atmosphere packaging (MAP) systems. Ground beef patties with chitosan (1%) or without chitosan (control) were packaged either in high-oxygen MAP (HIOX; 80% O(2)+20% CO(2)), carbon monoxide MAP (CO; 0.4% CO+19.6% CO(2)+80% N(2)), vacuum (VP), or aerobic packaging (PVC) and stored at 1 °C. Chitosan increased (P<0.05) redness of patties stored in PVC and CO, whereas it had no effect (P>0.05) in HIOX. Chitosan patties demonstrated lower (P<0.05) lipid oxidation than controls in all packaging. Control patties in PVC and HIOX exhibited greater (P<0.05) lipid oxidation than those in VP and CO, whereas chitosan patties in different packaging systems were not different (P>0.05) from each other. Our findings suggested that antioxidant effects of chitosan on ground beef are packaging-specific. PMID:20833484

  6. The use of chitosan as a coagulant in the pre-treatment of turbid sea water.

    PubMed

    Altaher, Hossam

    2012-09-30

    One of the problems that encounters desalination industry is the fouling that takes place due to the poor quality of the sea water received, especially when it rains. In such a situation, the sea water reaches the desalination plant having high turbidity. Chitosan was tested as a coagulant in the removal of the turbidity of sea water to replace inorganic coagulants having hazardous effects. Jar test was performed to test some factors that may affect the coagulation process. The factors tested were dose of coagulant (0-370 mg/L), initial pH (2-11), type of coagulant (chitosan versus metal coagulants), and the chitosan solvent. Chitosan's turbidity removal efficiency was found to be greater than ferrous sulfate and comparable to that of alum. While most researches emphasize the use of chitosan in acidic or neutral media, it worked well in the alkaline pH. The highest turbidity removal efficiency of 97.5% was obtained at initial pH of 8.1. The optimum dose was found to be 18 mg/L. Chitosan dissolved in HCl was found to perform better than that dissolved in acetic acid. Comparable turbidity removal efficiencies were obtained using alum and chitosan. However, much higher doses were used when using alum which implies higher cost and increase of residual aluminum concentration in treated water. PMID:22819482

  7. Preparation of monodisperse chitosan microcapsules with hollow structures using the SPG membrane emulsification technique.

    PubMed

    Akamatsu, Kazuki; Chen, Wei; Suzuki, Yukimitsu; Ito, Taichi; Nakao, Aiko; Sugawara, Takashi; Kikuchi, Ryuji; Nakao, Shin-ichi

    2010-09-21

    We describe herein successful preparations of monodisperse chitosan microcapsules with hollow structures using the SPG membrane emulsification technique. Two preparation procedures were examined in this study. In the first method, monodisperse calcium alginate microspheres were prepared and then coated with unmodified chitosan. Subsequently, tripolyphosphate treatment was conducted to physically cross-link chitosan and solubilize the alginate core at the same time. In the second method, photo-cross-linkable chitosan was coated onto the monodisperse calcium alginate microspheres, followed by UV irradiation to chemically cross-link the chitosan shell and tripolyphosphate treatment to solubilize the core. For both methods, it was determined that the average diameters of the chitosan microcapsules depended on those of the calcium alginate microparticles and that the microcapsules have hollow structures. In addition, the first physical cross-linking method using tripolyphosphate was found to be preferable to obtain the hollow structure, compared with the second method using chemical cross-linking by UV irradiation. This was because of the difference in the resistance to permeation of the solubilized alginate through the chitosan shell layers. PMID:20718480

  8. Chitosan/Riboflavin-modified demineralized dentin as a potential substrate for bonding.

    PubMed

    Fawzy, Amr S; Nitisusanta, Lorraine I; Iqbal, Kulsum; Daood, Umer; Beng, Lu Thong; Neo, Jennifer

    2013-01-01

    Previous studies have suggested different approaches to modify dentin collagen for potential improvement in bonding to dentin. Here, we are proposing a new approach to reinforce dentin collagen fibrils network by chitosan as a reinforcement phase and UVA-activated riboflavin as crosslinking agent within clinically acceptable time-frame as potential substrate for bonding. The effect of modifying demineralized dentin substrates with chitosan/riboflavin, with a gradual increase in chitosan content, was investigated by SEM, nano-indentation, conventional-mechanical testing and hydroxyproline (HYP) release at collagenolytic and/or hydrolytic challenges. The resin/dentin interface morphology, immediate bond strength and short-term bond durability were also investigated using etch-and-rinse dentin adhesive. Modification with chitosan/riboflavin increased the mechanical properties, enhanced the mechanical stability of demineralized dentin substrates against hydrolytic and/or collagenolytic degradation challenges and decreased HYP release with collagenase exposure. When chitosan was added to riboflavin at 20%v/v ratio, significant improvement in bond strength at 24 h and 6 months in distilled water was found indicating the positive dual effect on bonding to dentin. With the gradual increase in chitosan content, obliteration of interfibrillar-spaces that might adversely affect bonding to dentin was found. Although it has a synergetic effect, chitosan content is crucial for any subsequent application in adhesive dentistry. PMID:23127636

  9. Chitosan, the Marine Functional Food, Is a Potent Adsorbent of Humic Acid

    PubMed Central

    Chen, Jeen-Kuan; Yeh, Chao-Hsien; Wang, Lian-Chen; Liou, Tzong-Horng; Shen, Chia-Rui; Liu, Chao-Lin

    2011-01-01

    Chitosan is prepared by the deacetylation of chitin, the second-most abundant biopolymer in nature, and has applicability in the removal of dyes, heavy metals and radioactive waste for pollution control. In weight-reduction remedies, chitosan is used to form hydrogels with lipids and to depress the intestinal absorption of lipids. In this study, an experimental method was implemented to simulate the effect of chitosan on the adsorption of humic acid in the gastrointestinal tract. The adsorption capacity of chitosan was measured by its adsorption isotherm and analyzed using the Langmuir equation. The results showed that 3.3 grams of humic acid was absorbed by 1 gram of chitosan. The adsorption capacity of chitosan was much greater than that of chitin, diethylaminoethyl-cellulose or activated charcoal. Cellulose and carboxymethyl-cellulose, a cellulose derivative with a negative charge, could not adsorb humic acid in the gastrointestinal tract. This result suggests that chitosan entraps humic acid because of its positive charge. PMID:22363235

  10. A comparative study of sorption of chromium (III) onto chitin and chitosan

    NASA Astrophysics Data System (ADS)

    Singh, Pooja; Nagendran, R.

    2014-07-01

    Heavy metals have always been the most hazardous components in the wastewater of industries like electroplating, automobiles, mining facilities and fertilizer manufacturers. Treatment of heavy metal laden wastewater requires expensive operational and maintenance systems. Food processing industries create a huge amount of shell waste which is sold to poultry farms in powdered form but the quantity thus used is still not comparable to the left over waste. The shell contains chitin which acts as an adsorbent for the heavy metals and can be used to treat heavy metal wastewater. The paper presents a study on the use of chitin and its processed product, chitosan, to remove chromium. Shake flask experiment was conducted to compare the adsorptive capacity of chitin and chitosan for chromium removal from simulated solution and isotherm studies were carried out. The studies showed that the chitosan was a better adsorbent than chitin. Both chitin and chitosan gave best adsorption results at pH 3. Chitin exhibited maximum chromium removal of 49.98 % in 20 min, whereas chitosan showed 50 % removal efficiency at a contact time of 20 min showing higher adsorptive capacity for chromium than chitin. The Langmiur and Freundlich isotherm studies showed very good adsorption capacity and monolayer interaction according to the regression coefficient 0.973 for chitosan and 0.915 for chitin. The regression coefficient for Freundlich isotherm was 0.894 and 0.831 for chitosan and chitin, respectively.

  11. Effect of molecular weight reduction by gamma irradiation on chitosan film properties.

    PubMed

    García, Mario A; Pérez, Liliam; de la Paz, Nilia; González, Juan; Rapado, Manuel; Casariego, Alicia

    2015-10-01

    The present work aimed the influence of molecular weight (MW) reduction by irradiation with (60)Co and polymer concentration on some physical properties of chitosan films. Irradiation of chitosan with a MW of 275.221kDa and 74.74% of deacetylation degree was performed using a (60)Co source to provide doses of 5, 10, 20 and 50kGy to obtain chitosans with molecular weights of 247.847, 221.563, 126.469 and 77.063kDa, respectively. Films were prepared via the solution casting method. Film-forming solutions (FFS) of chitosan irradiated or not, were prepared at 1.5 and 2% (w/v) in a solution of lactic acid at 1% (v/v) and 0.1% (v/v) of Tween 80. The FFS were poured into glass plates of 400cm(2) and dried at 60°C during 10h without airflow. The decrease of MW and increase of chitosan concentration increased the tensil strength and water vapor permeability while decreased the elongation at break of the films. The chitosan MW did not significantly influence (p>0.05) the water solubility of films within a same polymer concentration. There was a decrease in the films' brightness with the increase of concentration and a decrease of the MW of irradiated chitosan, while the b* values of films increased and there was an increasing tendency of their apparent opacity. PMID:26117752

  12. Synthesis, characterization, and antibacterial activity of N,O-quaternary ammonium chitosan.

    PubMed

    Xu, Tao; Xin, Meihua; Li, Mingchun; Huang, Huili; Zhou, Shengquan; Liu, Juezhao

    2011-11-01

    N,N,N-Trimethyl O-(2-hydroxy-3-trimethylammonium propyl) chitosans (TMHTMAPC) with different degrees of O-substitution were synthesized by reacting O-methyl-free N,N,N-trimethyl chitosan (TMC) with 3-chloro-2-hydroxy-propyl trimethyl ammonium chloride (CHPTMAC). The products were characterized by (1)H NMR, FTIR and TGA, and investigated for antibacterial activity against Staphylococcus aureus and Escherichia coli under weakly acidic (pH 5.5) and weakly basic (pH 7.2) conditions. TMHTMAPC exhibited enhanced antibacterial activity compared with TMC, and the activity of TMHTMAPC increased with an increase in the degree of substitution. Divalent cations (Ba(2+) and Ca(2+)) strongly reduced the antibacterial activity of chitosan, O-carboxymethyl chitosan and N,N,N-trimethyl-O-carboxymethyl chitosan, but the repression on the antibacterial activity of TMC and TMHTMAPC was weaker. This indicates that the free amino group on chitosan backbone is the main functional group interacting with divalent cations. The existence of 100 mM Na(+) slightly reduced the antibacterial activity of both chitosan and its derivatives. PMID:21920510

  13. Nanostructured biocomposite films of high toughness based on native chitin nanofibers and chitosan

    PubMed Central

    Mushi, Ngesa E.; Utsel, Simon; Berglund, Lars A.

    2014-01-01

    Chitosan is widely used in films for packaging applications. Chitosan reinforcement by stiff particles or fibers is usually obtained at the expense of lowered ductility and toughness. Here, chitosan film reinforcement by a new type of native chitin nanofibers is reported. Films are prepared by casting from colloidal suspensions of chitin in dissolved chitosan. The nanocomposite films are chitin nanofiber networks in chitosan matrix. Characterization is carried out by dynamic light scattering, quartz crystal microbalance, field emission scanning electron microscopy, tensile tests and dynamic mechanical analysis. The polymer matrix nanocomposites were produced in volume fractions of 8, 22, and 56% chitin nanofibers. Favorable chitin-chitosan synergy for colloidal dispersion is demonstrated. Also, lowered moisture sorption is observed for the composites, probably due to the favorable chitin-chitosan interface. The highest toughness (area under stress-strain curve) was observed at 8 vol% chitin content. The toughening mechanisms and the need for well-dispersed chitin nanofibers is discussed. Finally, desired structural characteristics of ductile chitin biocomposites are discussed. PMID:25478558

  14. Chitosan nanoparticles for siRNA delivery: optimizing formulation to increase stability and efficiency.

    PubMed

    Ragelle, H; Riva, R; Vandermeulen, G; Naeye, B; Pourcelle, V; Le Duff, C S; D'Haese, C; Nysten, B; Braeckmans, K; De Smedt, S C; Jérôme, C; Préat, V

    2014-02-28

    This study aims at developing chitosan-based nanoparticles suitable for an intravenous administration of small interfering RNA (siRNA) able to achieve (i) high gene silencing without cytotoxicity and (ii) stability in biological media including blood. Therefore, the influence of chitosan/tripolyphosphate ratio, chitosan physicochemical properties, PEGylation of chitosan as well as the addition of an endosomal disrupting agent and a negatively charged polymer was assessed. The gene silencing activity and cytotoxicity were evaluated on B16 melanoma cells expressing luciferase. We monitored the integrity and the size behavior of siRNA nanoparticles in human plasma using fluorescence fluctuation spectroscopy and single particle tracking respectively. The presence of PEGylated chitosan and poly(ethylene imine) was essential for high levels of gene silencing in vitro. Chitosan nanoparticles immediately released siRNA in plasma while the inclusion of hyaluronic acid and high amount of poly(ethylene glycol) in the formulation improved the stability of the particles. The developed formulations of PEGylated chitosan-based nanoparticles that achieve high gene silencing in vitro, low cytotoxicity and high stability in plasma could be promising for intravenous delivery of siRNA. PMID:24389132

  15. Electrospinning of chitosan solutions in acetic acid with poly(ethylene oxide).

    PubMed

    Duan, Bin; Dong, Cunhai; Yuan, Xiaoyan; Yao, Kangde

    2004-01-01

    Electrospinning of chitosan solutions with poly(ethylene oxide) (PEO) in an aqueous solution of 2 wt% acetic acid was studied. The properties of the chitosan/PEO solutions, including conductivity, surface tension and viscosity, were measured. Morphology of the electrospun chitosan/PEO was observed by using scanning electron micrographs. Results showed that the ultrafine fibers could be generated after addition of PEO in 2:1 or 1:1 mass ratios of chitosan to PEO from 4-6 wt% chitosan/PEO solutions at 15 kV voltage, 20 cm capillary-collector distance and flow rate 0.1 ml/h. During electrospinning of the chitosan/PEO solutions, ultrafine fibers with diameters from 80 nm to 180 nm were obtained, while microfibers with visually thicker diameters could be formed as well. Results of X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and differential scanning calorimeter exhibited the larger electrospun microfibers were almost entirely made from PEO, while the electrospun ultrafine fibers mainly contained chitosan. PMID:15255527

  16. Insights on the interactions of chitosan with phospholipid vesicles. Part II: Membrane stiffening and pore formation.

    PubMed

    Mertins, Omar; Dimova, Rumiana

    2013-11-26

    The interactions between the polysaccharide chitosan and phospholipids are studied using giant unilamellar vesicles (GUVs). We explore both bare GUVs incubated in chitosan solution post vesicle formation and GUVs prepared using a reverse-phase method where the polymer is adsorbed on both sides of the membrane leaflet. The fluctuations of the vesicle membrane are significantly reduced in the presence of chitosan as characterized by the bending rigidity, which increases with chitosan concentration denoting physical restrictions imposed to the bilayer as a consequence of the interaction with the polysaccharide. In the absence of chitosan, the rigidity of the bare phosphatidylcholine vesicles is also observed to increase (about 3-fold) upon the incorporation of a small fraction (10 mol %) of phosphatidylglycerol. Pore formation caused by chitosan is evidenced by loss of optical contrast of the giant vesicles denoting exchange between internal and external solutions through the pores. Our study provides evidence for the potential of chitosan to affect the bilayer permeability and to disrupt negatively charged membranes as well as to promote adhesiveness of vesicles on glass surfaces. PMID:24168435

  17. In vivo efficacy of a chitosan/IL-12 adjuvant system for protein-based vaccines.

    PubMed

    Heffernan, Michael J; Zaharoff, David A; Fallon, Jonathan K; Schlom, Jeffrey; Greiner, John W

    2011-01-01

    Vaccines based on recombinant proteins require adjuvant systems in order to generate Th1-type immune responses. We have developed a vaccine adjuvant system using a viscous chitosan solution and interleukin (IL)-12, a Th1-inducing cytokine. The chitosan solution is designed to create a depot of antigen and IL-12 at a subcutaneous injection site. We measured the in vivo immune response of a vaccine containing 0.25, 1, or 4 ?g murine IL-12 and 75 ?g ovalbumin (OVA), formulated in a 1.5% chitosan glutamate solution. The chitosan/IL-12/OVA vaccine, in comparison to chitosan/OVA, IL-12/OVA, or OVA alone, elicited greater antigen-specific CD4(+) and CD8(+) T-cell responses, as determined by CD4(+) splenocyte proliferation, Th1 cytokine release, CD8(+) T-cell interferon-? release, and MHC class I peptide pentamer staining. The combination of chitosan and IL-12 also enhanced IgG2a and IgG2b antibody responses to OVA. Co-formulation of chitosan and IL-12 thus promoted the generation of a Th1 immune response to a model protein vaccine. PMID:20965561

  18. In vivo evaluation of chitosan as an adjuvant in subcutaneous vaccine formulations.

    PubMed

    Scherließ, Regina; Buske, Simon; Young, Katherine; Weber, Benjamin; Rades, Thomas; Hook, Sarah

    2013-10-01

    Vaccines utilising pure antigens instead of whole pathogens and alternative administration routes require the use of potent adjuvants and effective antigen delivery systems. Chitosan has been reported to act as both an adjuvant as well as a matrix for delivery systems. Chitosan is a natural product produced predominantly from crab shell and commercially available preparations vary in molecular weight, degree of deacetylation and purity. In this study, the impact of chitosan characteristics (molecular weight, degree of deacetylation, particle size, viscosity and impurities) on adjuvant activity were examined. It could be shown that the degree of immune response differed if different chitosan qualities were used and this could be attributed to different characteristics of the chitosan qualities: the immunoadjuvant effect of chitosan probably is a result of an interplay between chemical properties such as molecular weight and degree of deacetylation and physical properties such as particle size and preparation technique, which impacts characteristics such as solubility and viscosity. Hence, the chitosan quality to be used as adjuvant in vaccine preparations needs to be selected carefully. PMID:23933339

  19. Evaluation of the effectiveness and safety of chitosan derivatives as adjuvants for intranasal vaccines.

    PubMed

    Kobayashi, Takashi; Fukushima, Kenji; Sannan, Takanori; Saito, Noriko; Takiguchi, Yasuyuki; Sato, Yuko; Hasegawa, Hideki; Ishikawa, Koichi

    2013-04-01

    Intranasal immunization is currently used to deliver live virus vaccines such as influenza. However, to develop an intranasal vaccine to deliver inactivated virus, a safe and effective adjuvant is necessary to enhance the mucosal immune response. Here, we demonstrate the effectiveness of a chitosan microparticle (1-20 ?m, 50 kDa, degree of deacetylation=85%) and a cationized chitosan (1000 kDa, degree of deacetylation=85%) derived from natural crab shells as adjuvants for an intranasal vaccine candidate. We examined the effectiveness of chitosan derivatives as an adjuvant by co-administering them with ovalbumin (OVA) intranasally in BALB/c mice, polymeric Ig receptor knockout (pIgR-KO) mice, and cynomolgus monkeys (Macaca fascicularis). pIgR-KO mice were used to evaluate S-IgA production on the mucosal surface without nasal swab collection. Administration of OVA with chitosan microparticles or cationized chitosan induced a high OVA-specific IgA response in the serum of pIgR-KO mice and a high IgG response in the serum of BALB/c mice and cynomolgus monkeys. We also found that administration of chitosan derivatives did not have a detrimental effect on cynomolgus monkeys as determined by complete blood count, blood chemistries, and gross pathology results. These results suggest that chitosan derivatives are safe and effective mucosal adjuvants for intranasal vaccination. PMID:23509985

  20. Photochemical and antimicrobial properties of silver nanoparticle-encapsulated chitosan functionalized with photoactive groups.

    PubMed

    Mathew, Thomas V; Kuriakose, Sunny

    2013-10-01

    Chitosan was functionalized with 4-((E)-2-(3-hydroxynaphthalen-2-yl)diazen-1-yl)benzoic acid by the coupling of the hydroxyl functional groups of chitosan with carboxylic acid group of the dye by DCC coupling method. The silver nanoparticles were prepared by sol-gel method of nanoparticle synthesis. Silver nanoparticle-encapsulated functionalized chitosan was prepared by the phase transfer method. The products were characterized by FTIR, UV-Vis, fluorescence and NMR spectroscopic methods and by SEM and TEM analysis. The photochemical properties of silver nanoparticle-encapsulated chitosan functionalized with 4-((E)-2-(3-hydroxynaphthalen-2-yl)diazen-1-yl)benzoic acid was studied in detail. The light-fastening properties of the chromophoric system was enhanced when attached to chitosan, and it can be further improved by the encapsulation of silver nanoparticles. The antibacterial analysis of silver nanoparticle-encapsulated functionalized chitosan was carried out against Staphylococcus aureus and Escherichia coli and against fungal species such as Aspergillus flavus and Aspergillus terreus. This study showed that silver nanoparticles-encapsulated functionalized chitosan can be used for antibacterial and antifungal applications. PMID:23910360

  1. Enhanced anti-topoisomerase II activity by mucoadhesive 4-CBS-chitosan/poly (lactic acid) nanoparticles.

    PubMed

    Songsurang, Kultida; Suvannasara, Phruetchika; Phurat, Chuttree; Puthong, Songchan; Siraleartmukul, Krisana; Muangsin, Nongnuj

    2013-11-01

    In this study, the biodegradable mucoadhesive 4-carboxybenzensulfonamide chitosan (4-CBS-chitosan)/poly (lactic acid) (PLA) nanoparticles were fabricated by the electrospray ionization technique for enhancing anti-topoisomerase II (Topo II) activity. The obtained (4-CBS-chitosan/PLA)-DOX nanoparticles were characterized using SEM, particle size analyzer. We emphasis on encapsulation efficiency, in vitro drug release behavior and also performed in vitro studies of Topo II inhibitory activity using gel electrophoresis. In addition, the cytotoxicity of the 4-CBS-chitosan/PLA nanoparticles using MTT assay was also studied. The mean particle size of spherical shaped (4-CBS-chitosan/PLA)-DOX is less than 300 nm. The DOX loaded 4-CBS-chitosan/PLA composite nanoparticles produced high entrapment efficiency of 85.8% and provided the prolonged release of DOX extended to 26 days and also still had strong Topo II inhibitory activity up to 77.4%. Overall, it was shown that 4-CBS-chitosan/PLA nanoparticles could be promising carriers for controlled delivery of anticancer drugs. PMID:24053811

  2. Novel chitosan-based pH-sensitive and disintegrable polyelectrolyte nanogels.

    PubMed

    Yuan, Fang; Wang, Shasha; Chen, Gaojian; Tu, Kehua; Jiang, Hongliang; Wang, Li-Qun

    2014-10-01

    A novel approach to design pH-sensitive and disintegrable polyelectrolyte nanogels composed of citraconic-based N-(carboxyacyl) chitosan (polyanion) and quaternary chitosan (polycation) was reported. Firstly, the hydrolysis of citraconic-modified chitosan was monitored using fluorescamine assay and it could selectively dissociate in acidic media (e.g., pH ?5.0) due to the isomerization during the addition of citraconic anhydride to chitosan. Secondly, the self-assembly behaviors of different polyelectrolyte pairs between citraconic-based chitosan and quaternary chitosan were investigated via colloidal titration assay. It was indicated that the difference in molecular weight (MW) of opposite charged polyelectrolytes played an important role on the formation of polyelectrolyte nanogels. Results showed that polyelectrolyte nanogels (ca. 300nm in size) only formed when polyanion and polycation had a very large difference in MW. The pH-sensitive behavior of polyelectrolyte nanogels was comprehensively investigated by dynamic light scattering (DLS) and transmission electron microscope (TEM). The incorporation of charge-conversional citraconic-based chitosan into polyelectrolyte complexes has provided an effective approach to prepare polyelectrolyte nanogels which were very stable at neutral pH but disintegrated quickly in acidic media. PMID:25042598

  3. Emulsification efficiency of adsorbed chitosan for bacterial cells accumulation at the oil-water interface.

    PubMed

    Archakunakorn, Somwit; Charoenrat, Nattapat; Khamsakhon, Somruethai; Pongtharangkul, Thunyarat; Wongkongkatep, Pravit; Suphantharika, Manop; Wongkongkatep, Jirarut

    2015-04-01

    The use of bacterial cell or biocatalyst for industrial synthetic chemistry is on the way of significant growth since the biocatalyst requires low energy input compared to the chemical synthesis and can be considered as a green technology. However, majority of natural bacterial cell surface is hydrophilic which allows poor access to the hydrophobic substrate or product. In this study, Escherichia coli (E. coli) as a representative of hydrophilic bacterial cells were accumulated at the oil-water interface after association with chitosan at a concentration range of 0.75-750 mg/L. After association with negatively charged E coli having a ? potential of -19.9 mV, a neutralization of positively charged chitosan occurred as evidenced by an increase in the ? potential value of the mixtures with increasing chitosan concentration up to +3.5 mV at 750 mg/L chitosan. Both emulsification index and droplet size analysis revealed that chitosan-E. coli system is an excellent emulsion stabilizer to date because the threshold concentration was as low as 7.5 mg/L or 0.00075% w/v. A dramatic increase in the surface hydrophobicity of the E. coli as evidenced by an increase in contact angle from 19 to 88° with increasing chitosan concentration from 0 to 750 mg/L, respectively, resulted in an increase in the stability of oil-in-water emulsions stabilized by chitosan-E. coli system. The emulsion was highly stable even the emulsification was performed under 20% salt condition, or temperature ranged between 20 and 50 °C. Emulsification was failed when the oil volume fraction was higher than 0.5, indicating that no phase inversion occurred. The basic investigation presented in this study is a crucial platform for its application in biocatalyst industry and bioremediation of oil spill. PMID:25341365

  4. A hybrid thermo-sensitive chitosan gel for sustained release of Meloxicam.

    PubMed

    Wang, Ye; Chen, Minyan; Li, Xiang; Huang, Yongzhuo; Liang, Wenquan

    2008-01-01

    The purpose of this work was to develop a multi-phase gel system for sustained release drug delivery. A thermo-sensitive hydrogel composed of chitosan and glycerol was prepared, and then an o/w emulsion was introduced to the thermo-sensitive gel in order to modulate the gelation behavior. Meloxicam was chosen as a model drug in this study and its release profile was investigated. This study revealed that the factors such as pH, chitosan molecular mass and glycerol concentration could significantly influence the gel formation. Chitosan with a molecular mass of 950 kDa and glycerol proportion ranging from 30 to 60% can form a pH-dependent thermo-sensitive gel system. Both the chitosan-glycerol gel and chitosan-glycerol-emulsion gel systems were applied in delivering drugs. The drug release from the two gels was both in Higuchi mode. Higuchi moduli were 3.04 x 10(-3) mg x h((1/2)) in the chitosan-glycerol-emulsion gel and 1.28 mg x h((1/2)) in the chitosan- glycerol gel. The former was significantly slower in sustained release. The in vivo investigation on the chitosan-glycerol gel indicated that the gel may be useful in sustained drug release in situ. Thermosensitive hydrogels composed of chitosan and glycerol were well formed and could act as a sustained release drug carrier in the work, it showed that this hybrid thermo-sensitive hydrogel system may be a promising sustained release drug carrier. PMID:18727863

  5. Preparation of chitosan-coated polyethylene packaging films by DBD plasma treatment.

    PubMed

    Theapsak, Siriporn; Watthanaphanit, Anyarat; Rujiravanit, Ratana

    2012-05-01

    Polyethylene (PE) packaging films were coated with chitosan in order to introduce the antibacterial activity to the films. To augment the interaction between the two polymers, we modified the surfaces of the PE films by dielectric barrier discharge (DBD) plasma before chitosan coating. After that the plasma-treated PE films were immersed in chitosan acetate solutions with different concentrations of chitosan. The optimum plasma treatment time was 10 s as determined from contact angle measurement. Effect of the plasma treatment on the surface roughness of the PE films was investigated by atomic force microscope (AFM) while the occurrence of polar functional groups was observed by X-ray photoelectron spectroscope (XPS) and Fourier transformed infrared spectroscope (FTIR). It was found that the surface roughness as well as the occurrence of oxygen-containing functional groups (i.e., C?O, C-O, and -OH) of the plasma-treated PE films increased from those of the untreated one, indicating that the DBD plasma enhanced hydrophilicity of the PE films. The amounts of chitosan coated on the PE films were determined after washing the coated films in water for several number of washing cycles prior to detection of the chitosan content by the Kjaldahl method. The amounts of chitosan coated on the PE films were constant after washing for three times and the chitosan-coated PE films exhibited appreciable antibacterial activity against Escherichia coli and Staphylococcus aureus. Hence, the obtained chitosan-coated PE films could be a promising candidate for antibacterial food packaging. PMID:22512401

  6. Effect of PEGylation on the toxicity and permeability enhancement of chitosan.

    PubMed

    Casettari, Luca; Vllasaliu, Driton; Mantovani, Giuseppe; Howdle, Steven M; Stolnik, Snow; Illum, Lisbeth

    2010-11-01

    The aim of the present work is to investigate if conditions can be devised where PEGylation of chitosan would reduce its toxicity toward the nasal mucosa while maintaining its ability to open the cellular tight junctions and, consequently, produce an enhancement of macromolecular permeability. A series of mPEG-g-chitosan copolymers with varying levels of mPEG substitution, mPEG molecular weight, and chitosan molecular weight were synthesized by grafting carboxylic acid-terminated mPEGs (Mw 1.9 and 5.0 × 10(3) g mol(-1)) to chitosans (Mw 28.9 and 82.0 × 10(3) g mol(-1)) using a NHS/EDC coupling system. The synthesized mPEG-g-chitosans were fully characterized using a number of techniques, including FT-IR, (1)H NMR, and SEC-MALLS and their physicochemical properties were analyzed by TGA and DSC. Thereafter, the conjugates were tested for their cytotoxicity and tight junction modulating property in a relevant cell model, a mucus producing Calu-3 monolayer. mPEG-g-chitosan conjugates exhibited reduced toxicity toward cells, as compared to unmodified chitosan counterparts. Furthermore, the conjugates demonstrated a dramatic effect on cell monolayer transepithelial electrical resistance (TEER) and enhancement of permeability of model macromolecules. TEER and permeability-enhancing effects, as measurable indicators of tight junction modulation, were found to be pH-dependent and were notably more pronounced than those exhibited by unmodified chitosans. This work therefore demonstrates that conditions can be contrived where PEGylation improves the toxicity profile of chitosan, while preserving its effect on epithelial tight junctions in the nose. PMID:20873757

  7. A comparison of physicochemical properties of sterilized chitosan hydrogel and its applicability in a canine model of periodontal regeneration.

    PubMed

    Zang, Shengqi; Dong, Guangying; Peng, Bo; Xu, Jie; Ma, Zhiwei; Wang, Xinwen; Liu, Lingxia; Wang, Qintao

    2014-11-26

    Chitosan has previously been exploited as a scaffold in tissue engineering processes. To avoid infection, chitosan must be sterilized prior to contact with bodily fluids or blood. Previous research has shown that autoclaved chitosan solution lead to decreased molecular weight, dynamic viscosity, and rate of gelling. We prepared a thermosensitive chitosan hydrogel using autoclaved chitosan powder (121 °C, 10 min) and ?-glycerophosphate (chitosan-PA/GP) and compared the physicochemical properties and biocompatibility in vitro with autoclaved chitosan solution/GP hydrogel. The chitosan-PA/GP hydrogel had a shortened gelation time, higher viscosity, increased water absorption, appropriate degradation time, porous structure, and no obvious cytotoxicity on human periodontal ligament cells. Scanning electron microscopy demonstrated that the cells exhibited a normal morphology. The chitosan-PA/GP hydrogel promoted periodontal tissue regeneration in dog class III furcation defects. The chitosan-PA/GP thermosensitive hydrogel displayed suitable physicochemical properties and biocompatibilities and represents a promising candidate as an injectable tissue engineering scaffold. PMID:25256481

  8. Enhancement of glycated chitosan in laser cancer treatment

    NASA Astrophysics Data System (ADS)

    Chen, Wei R.; Jeong, Sang W.; Korbelik, Mladen; Bartels, Kenneth E.; Martin, Steven D.; Sun, Jinghai; Liu, Hong; Nordquist, Robert E.

    2004-07-01

    Glycated chitosan (GC), a novel immunoadjuvant, has been used in combination with selective photothermal interaction in treatment of metastatic tumors. It has shown to be able to induce anti-tumor immunity and to enhance treatment efficacy. To further study the effects of glycated chitosan, photodynamic therapy (PDT) was used as the mechanism of direct tumor killing. Specifically, Photofrin-based PDT was used to treat EMT6 mammary tumors in mice and mTHPC-based PDT was used to treat Line 1 lung tumors in mice. In both cases, GC was administered immediately after the PDT treatment around the treated tumors. With EMT6 tumors, the use of GC improved the PDT-mediated tumor cure rate from 37.5% to 62.5% with 0.1 ml of 0.5% GC solution and to 75% with 0.1 ml of 1.5% GC solution. With the Line 1 tumors, the non-curative PDT treatment was converted into a 37.5% cure-rate by using a post-PDT peritumoral injection of 0.09 ml of 1.67% GC solution. In comparison, the treatments with GC alone or GC plus PDT light (no photosensitizer) produced no tumor regression and had no influence on the tumor growth rate, when compared to non-treated control tumors. GC was also used for the treatment of B16 melanoma in mice, using a combination of in situ application of GC and an irradiation of an 805-nm laser. The survival rates of the mice bearing melanoma tumors increased significantly when the laser and GC were applied, particularly when GC was applied 24 hours prior to the laser irradiation. These results strongly suggested that glycated chitosan played a significant role in the treatment of tumors.

  9. Synthesis, characterization and antibacterial activity of quaternized N , O -(2-carboxyethyl) chitosan

    Microsoft Academic Search

    Zhao-sheng Cai; Zhan-qian Song; Chun-sheng Yang; Shi-bin Shang; Yan-bai Yin

    2009-01-01

    N,O-(2-carboxyethyl)chitosan (N,O-2-CEC) was prepared from chitosan with 3-chloropropionic acid as modifying agent and NaOH as catalyst. Different quaternary\\u000a ammonium groups were introduced into N,O-2-CEC by the reaction between N,O-2-CEC and different 2,3-epoxypropyl trialkyl ammonium chlorides in the presence of 25% NaOH aqueous solution, and obtained\\u000a different quaternized N,O-2-carboxyethyl chitosans (QCECs). Structures of QCECs were characterized by FT-IR, 1HNMR and gel

  10. Surface modification of gold and quantum dot nanoparticles with chitosan for bioapplications

    Microsoft Academic Search

    Wee Beng Tan; Y Zhang

    2005-01-01

    Gold (Au) and quantum dot (QD) nanoparticles, which have been\\u000a extensively used in many fields, were encapsulated with a natural\\u000a polymer, chitosan, to improve their biocompatibility. Characterization\\u000a was performed using ultraviolet-visible, dynamic light scattering,\\u000a atomic force microscopy, and transmission electron microscope analyses.\\u000a It was found that a Au\\/chitosan ratio of 1:1 and smaller produced\\u000a chitosan-encapsulated Au nanoparticles of a sufficiently

  11. Synthesis and characterization of some acyl thiourea derivatives of chitosan and their biocidal activities.

    PubMed

    Elkholy, Said S; Salem, Hend A; Eweis, Mohamed; Elsabee, Maher Z

    2014-09-01

    Three acyl derivatives of chitosan (CS) with different side chains were synthesized and their structures were characterized. Their swelling behavior was investigated. The antifungal behavior of these chitosan derivatives was investigated in vitro on the mycelial growth, sporulation and germination of conidia or sclerotia of the sugar-beet pathogens, Rhizoctonia solani K"uhn (AG2-2) and Sclerotium rolfsii Sacc. All the prepared derivatives had a significant inhibiting effect on the different stages of development on the germination of conidia or sclerotia of all the investigated fungi. In the absence of chitosan and its derivative, R. solani exhibited the fastest growth of the fungi studied. PMID:25002014

  12. Insights on the interactions of chitosan with phospholipid vesicles. Part I: Effect of polymer deprotonation.

    PubMed

    Mertins, Omar; Dimova, Rumiana

    2013-11-26

    Interactions between the polysaccharide chitosan and negatively charged phospholipid liposomes were studied as a function of compositional and environmental conditions. Using isothermal titration calorimetry, different levels of deprotonation of chitosan in acidic solutions were attained with titration of the fully protonated polymer at pH 4.48 into solutions with increasing pH. The process was found to be highly endothermic. We then examined the interaction of the polymer with vesicles in solutions of different pH. Even when partially deprotonated, the chitosan chains retain their affinity to the negatively charged liposomes. However, the stronger adsorption results in lower organization of the chains over the membrane. PMID:24168397

  13. Electrical transport and thermochromic properties of polyaniline/chitosan/Co3O4 ternary nano composite

    NASA Astrophysics Data System (ADS)

    V, Mini; Kamath, Archana; S, Raghu; Chapi, Sharanappa; H, Devendrappa

    2015-06-01

    A new Polyaniline/ chitosan/ Co3O4 (CPAESCO) ternary nanocomposite is prepared by in situ oxidation polymerization of aniline in the presence of (NH4)2S2O8, chitosan and Co3O4. The Structural, Thermal, Optical and Electrical features of Polyaniline (PANI), Polyaniline/ chitosan (CPANI) and CPAESCO were analyzed using FT-IR, TGA, UV-vis analysis and Impedance spectroscopy by varying temperature. The results show that the introduction of the Co3O4 nanoparticles into CPANI matrix enhanced its properties. Mott's parameters show 3D -VRH Type conduction in it.

  14. Characterization of films based on chitosan lactate and its blends with oxidized starch and gelatin.

    PubMed

    Kowalczyk, Dariusz; Kordowska-Wiater, Monika; Nowak, Jakub; Baraniak, Barbara

    2015-06-01

    Minimal inhibitory concentration (MIC) of chitosan lactate (CHL) was tested against bacteria and phytopathogenic fungi. Then, the structural, physicochemical and antimicrobial properties of films based on CHL, oxidized potato starch (OPS), and gelatin (GEL) were investigated. With the exception of Rhizopus nigricans, CHL was effective against the target organisms. Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) were more sensitive to CHL than Gram-negative bacteria (Pectobacterium carotovorum and Escherichia coli). Cryo-SEM images showed total miscibility between the polymers in the blends and the ATR-FTIR spectra revealed that there was an interaction among the polymeric components. Pure CHL films displayed the highest moisture content (25.51%), water vapor permeability (48.78gmmm(-2)d(-1)kPa(-1)), and the lowest tensile and puncture strength (2.00 and 1.45MPa, respectively) among the studied films. CHL50/GEL50 films had lower permeability, higher mechanical strength, and lower elongation compared to CHL50/OPS50 films. Films obtained from CHL and CHL50/GEL50 were completely water-soluble and did not show sorbitol recrystallization. The incorporation of CHL into OPS and GEL films did not affect their transparency and improved UV-blocking capacity. CHL films were the only ones that exhibited antibacterial efficiency. Antifungal activities against Alternaria alternata and Monilinia fructigena were detected for CHL and CHL50/GEL50 films. PMID:25841370

  15. Intravesical chitosan/interleukin-12 immunotherapy induces tumor-specific systemic immunity against murine bladder cancer.

    PubMed

    Smith, Sean G; Koppolu, Bhanu Prasanth; Ravindranathan, Sruthi; Kurtz, Samantha L; Yang, Lirong; Katz, Matthew D; Zaharoff, David A

    2015-06-01

    Bladder cancer is a highly recurrent disease in need of novel, durable treatment strategies. This study assessed the ability of an intravesical immunotherapy composed of a coformulation of the biopolymer chitosan with interleukin-12 (CS/IL-12) to induce systemic adaptive tumor-specific immunity. Intravesical CS/IL-12 immunotherapy was used to treat established orthotopic MB49 and MBT-2 bladder tumors. All mice receiving intravesical CS/IL-12 immunotherapy experienced high cure rates of orthotopic disease. To investigate the durability and extent of the resultant adaptive immune response, cured mice were rechallenged both locally (intravesically) and distally. Cured mice rejected 100 % of intravesical tumor rechallenges and 50-100 % of distant subcutaneous rechallenges in a tumor-specific manner. The ability of splenocytes from cured mice to lyse targets in a tumor-specific manner was assessed in vitro, revealing that lytic activity of splenocytes from cured mice was robust and tumor specific. Protective immunity was durable, lasting for at least 18 months after immunotherapy. In an advanced bladder cancer model, intravesical CS/IL-12 immunotherapy controlled simultaneous orthotopic and subcutaneous tumors in 70 % of treated mice. Intravesical CS/IL-12 immunotherapy creates a robust and durable tumor-specific adaptive immune response against bladder cancer. The specificity, durability, and potential of this therapy to treat both superficial and advanced disease are deserving of consideration for clinical translation. PMID:25754122

  16. Magnetic chitosan nanocomposite for hyperthermia therapy application: Preparation, characterization and in vitro experiments

    NASA Astrophysics Data System (ADS)

    Shete, P. B.; Patil, R. M.; Thorat, N. D.; Prasad, A.; Ningthoujam, R. S.; Ghosh, S. J.; Pawar, S. H.

    2014-01-01

    Nanocrystals of magnetite (Fe3O4) were prepared by alkaline precipitation. The precursor used for synthesis was ferrous chloride only and the reaction was carried out in absence of any oxidant. The synthesized pure phase magnetic nanoparticles (MNPs) were coated with a biocompatible polymer, chitosan (CS). FTIR and TGA confirm coating of CS on MNPs. Both bare and coated MNPs (Fe3O4 and CS-Fe3O4) show particle size 21.8 ± 5.3 and 15.1 ± 5.0 nm respectively. The magnetization values of both the MNPs are 51.68 and 49.96 emu/g at room temperature respectively. Negligible Coercivity and Remenance values at room temperature imply superparamagnetic behavior of the MNPs. The MNPs are studied for their induction heating abilities at 167.6, 251.4 and 335.2 Oe (equivalent to 13.3, 20.0 and 26.7 kA m-1 respectively), in order to use them in magnetic fluid hyperthermia therapy. At 335.2 Oe, CS coated nanoparticles (NPs) show maximum SAR of 118.85 W/g, while bare NPs show SAR of 79.32 W/g. Low cytotoxic effects of both the MNPs on L929 cell line proved their suitability for in vivo applications. NH2 group rendered by CS can further be used for conjugation of biomolecules to make them suitable candidates for biosensing and targeted drug delivery.

  17. Chitosan Oligosaccharides Inhibit/Disaggregate Fibrils and Attenuate Amyloid ?-Mediated Neurotoxicity

    PubMed Central

    Dai, Xueling; Hou, Wanqi; Sun, Yaxuan; Gao, Zhaolan; Zhu, Shigong; Jiang, Zhaofeng

    2015-01-01

    Alzheimer’s disease (AD) is characterized by a large number of amyloid-? (A?) deposits in the brain. Therefore, inhibiting A? aggregation or destabilizing preformed aggregates could be a promising therapeutic target for halting/slowing the progression of AD. Chitosan oligosaccharides (COS) have previously been reported to exhibit antioxidant and neuroprotective effects. Recent study shows that COS could markedly decrease oligomeric A?-induced neurotoxicity and oxidative stress in rat hippocampal neurons. However, the potential mechanism that COS reduce A?-mediated neurotoxicity remains unclear. In the present study, our findings from circular dichroism spectroscopy, transmission electron microscope and thioflavin T fluorescence assay suggested that COS act as an inhibitor of A? aggregation and this effect shows dose-dependency. Moreover, data from thioflavin T assay indicated that COS could significantly inhibit fibrils formation and disrupt preformed fibrils in a dose-dependent manner. Furthermore, the addition of COS attenuated A?1-42-induced neurotoxicity in rat cortical neurons. Taken together, our results demonstrated for the first time that COS could inhibit A?1-42 fibrils formation and disaggregate preformed fibrils, suggesting that COS may have anti-A? fibrillogenesis and fibril-destabilizing properties. These findings highlight the potential role of COS as novel therapeutic agents for the prevention and treatment of AD. PMID:26006224

  18. Chitosan Oligosaccharides Inhibit/Disaggregate Fibrils and Attenuate Amyloid ?-Mediated Neurotoxicity.

    PubMed

    Dai, Xueling; Hou, Wanqi; Sun, Yaxuan; Gao, Zhaolan; Zhu, Shigong; Jiang, Zhaofeng

    2015-01-01

    Alzheimer's disease (AD) is characterized by a large number of amyloid-? (A?) deposits in the brain. Therefore, inhibiting A? aggregation or destabilizing preformed aggregates could be a promising therapeutic target for halting/slowing the progression of AD. Chitosan oligosaccharides (COS) have previously been reported to exhibit antioxidant and neuroprotective effects. Recent study shows that COS could markedly decrease oligomeric A?-induced neurotoxicity and oxidative stress in rat hippocampal neurons. However, the potential mechanism that COS reduce A?-mediated neurotoxicity remains unclear. In the present study, our findings from circular dichroism spectroscopy, transmission electron microscope and thioflavin T fluorescence assay suggested that COS act as an inhibitor of A? aggregation and this effect shows dose-dependency. Moreover, data from thioflavin T assay indicated that COS could significantly inhibit fibrils formation and disrupt preformed fibrils in a dose-dependent manner. Furthermore, the addition of COS attenuated A?1-42-induced neurotoxicity in rat cortical neurons. Taken together, our results demonstrated for the first time that COS could inhibit A?1-42 fibrils formation and disaggregate preformed fibrils, suggesting that COS may have anti-A? fibrillogenesis and fibril-destabilizing properties. These findings highlight the potential role of COS as novel therapeutic agents for the prevention and treatment of AD. PMID:26006224

  19. Preparation and evaluation of lipid vesicles of camptothecin as targeted drug delivery system.

    PubMed

    Prabhakara, Prabhu; Zenia, Teles; Marina, Koland; Shama, Khandige Prasanna; Girish, Shetty Nisha; Matapady, Nairy Harish

    2013-07-01

    Site-specific delivery of anticancer based therapy of human cancers has led to several remarkable outcomes, particularly in the therapy of breast cancer and lymphoma. Camptothecin, a plant secondary metabolite is widely used in the treatment of metastatic breast cancer and lymphoma. However its side effect profile often results in cessation of therapy. In this study the principle of both active as well as passive targeting using camptothecin loaded stealth liposomes as per the magic gun approach was followed. Stealth liposomes of camtothecin were prepared by thin film hydration method using a PEGylated phospholipid like DSPE-MPEG 2000. Similarly conventional liposomes were prepared using phospholipids like DPPC, DSPC. Conventional liposomes were coated with a hydrophilic biocompatible polymer like chitosan. It was found that chitosan coating of the conventional liposomes increased the physical stability of the liposomal suspension. Further, chitosan coated conventional liposomes and the PEGylated liposomes released the drug for a prolonged period of time, compared to the uncoated conventional liposomes. In vivo screening of the formulations for their antitumor efficacy was carried out in rats. Breast cancer was induced in female Sprague-Dawley rats using an indirectly acting chemical carcinogen DMBA (7, 12 dimethyl benz(a)anthracene). It was found that there was significant decrease (P>0.01) in tumor volume in the rat group treated with test 2 formulation and test 1 formulation compared to standard free CPT. However the chitosan coated liposomal formulation showed a better antitumor efficacy than that of the PEGylated liposomal formulation. PMID:23811458

  20. Receptor-mediated gene delivery by folic acid-modified stearic acid-grafted chitosan micelles

    PubMed Central

    Du, Yong-Zhong; Cai, Li-Li; Li, Jin; Zhao, Meng-Dan; Chen, Feng-Ying; Yuan, Hong; Hu, Fu-Qiang

    2011-01-01

    Background Cationic polymers have been accepted as effective nonviral vectors for gene delivery with low immunogenicity unlike viral vectors. However, the lack of organ or cell specificity sometimes hampers their application and the modification of polymeric vectors has also shown successful improvements in achieving cell-specific targeting delivery and in promoting intracellular gene transfer efficiency. Methods A folic acid-conjugated stearic acid-grafted chitosan (FA-CS-SA) micelle, synthesized by a 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide-coupling reaction, was designed for specific receptor-mediated gene delivery. Results Due to the cationic properties of chitosan, the micelles could compact the plasmid DNA (pDNA) to form micelle/pDNA complexes nanoparticles. The particle size and zeta potential of the FA-CS-SA/pDNA complexes with different N/P ratios were 100–200 nm and ?20 to ?10 mV, respectively. The DNase I protection assay indicated that the complexes can efficiently protect condensed DNA from enzymatic degradation by DNase I. A cytotoxicity study indicated that the micelles exhibited less toxicity in comparison with LipofectamineTM 2000. Using SKOV3 and A549 as model tumor cells, the cellular uptake of micelles was investigated. Conclusion It was found that cellular uptake of FA-CS-SA in SKOV3 cells with higher folate receptor expression was faster than that in A549 cells with a short incubation time. Luciferase assay and green fluorescent protein detection were used to confirm that FA-CS-SA could be an effective gene vector. Transfection efficiency of the FA-CS-SA/pDNA complexes in SKOV3 cells was enhanced up to 2.3-fold compared with that of the CS-SA/pDNA complexes. However, there was no significant difference between the transfection efficiencies of the two complexes in A549 cells. Importantly, the transfection efficiency of FA-CS-SA/pDNA decreased with free FA pretreatment in SKOV3 cells. It was concluded that the increase in transfection efficiency of the FA-CS-SA/pDNA complexes was attributed to folate receptor-mediated endocytosis. PMID:21845046

  1. Modification of Decellularized Goat-Lung Scaffold with Chitosan/Nanohydroxyapatite Composite for Bone Tissue Engineering Applications

    PubMed Central

    Gupta, Sweta K.; Dinda, Amit K.; Potdar, Pravin D.; Mishra, Narayan C.

    2013-01-01

    Decellularized goat-lung scaffold was fabricated by removing cells from cadaver goat-lung tissue, and the scaffold was modified with chitosan/nanohydroxyapatite composite for the purpose of bone tissue engineering applications. MTT assay with osteoblasts, seeded over the chitosan/nanohydroxyapatite-modified decellularized scaffold, demonstrated significantly higher cell growth as compared to the decellularized scaffold without modification. SEM analysis of cell-seeded scaffold, after incubation for 7 days, represented a good cell adhesion, and the cells spread over the chitosan/nanohydroxyapatite-modified decellularized scaffold. Expression of bone-tissue-specific osteocalcin gene in the osteoblast cells grown over the chitosan/nanohydroxyapatite-modified decellularized scaffold clearly signifies that the cells maintained their osteoblastic phenotype with the chitosan/nanohydroxyapatite-modified decellularized scaffold. Therefore, it can be concluded that the decellularized goat-lung scaffold-modified with chitosan/nanohydroxyapatite composite, may provide enhanced osteogenic potential when used as a scaffold for bone tissue engineering. PMID:23841083

  2. Release of triamcinolone acetonide from mucoadhesive polymer composed of chitosan and poly(acrylic acid) in vitro.

    PubMed

    Ahn, Jae-Soon; Choi, Hoo-Kyun; Chun, Myong-Kwan; Ryu, Jei-Man; Jung, Jae-Hee; Kim, Yue-Un; Cho, Chong-Su

    2002-03-01

    Transmucosal drug delivery (TMD) system using mucoadhesive polymer has been recently interested due to the rapid onset of action, high blood level, avoidance of the first-pass effect and the exposure of the drug to the gastrointestinal tract. A novel mucoadhesive polymer complex composed of chitosan and poly(acrylic acid) (PAA) was prepared by template polymerization of acrylic acid in the presence of chitosan for the TMD system. Triamcinolone acetonide (TAA) was loaded into the chitosan/PAA polymer complex film. TAA was evenly dispersed in chitosan, PAA polymer complex film without interaction with polymer complex. Release behavior of TAA from the mucoadhesive polymer film was dependent on time, pH, loading content of drug, and chitosan PAA ratio. The analysis of the drug release from the mucoadhesive film showed that TAA might be released from the chitosan/PAA polymer complex film through non-Fickian diffusion mechanism. PMID:11829436

  3. Chitosan microbeads for encapsulation of thyme (Thymus serpyllum L.) polyphenols.

    PubMed

    Trifkovi?, Kata T; Milašinovi?, Nikola Z; Djordjevi?, Verica B; Kruši?, Melina T Kalagasidis; Kneževi?-Jugovi?, Zorica D; Nedovi?, Viktor A; Bugarski, Branko M

    2014-10-13

    In this work chitosan microbeads were prepared by emulsion technique and loaded with thyme polyphenols by diffusion from an external aqueous solution of Thymus serpyllum L. The effects of concentrations of chitosan (1.5-3% (w/v)) and GA (glutaraldehyde) (0.1-0.4% (v/v)), as a crosslinking agent on the main properties of microbeads were assessed. The obtained microgel beads from ? 220 to ? 790 ?m in diameter were exposed to controlled drying process at air (at 37 °C) after which they contracted to irregular shapes (? 70-230 ?m). The loading of dried microbeads with polyphenols was achieved by swelling in the acidic medium. The swelling rate of microbeads decreased with the increase in GA concentration. Upon this rehydration, thyme polyphenols were effectively encapsulated (active load of 66-114 mg GAE g(beads)(-1)) and the microbeads recovered a spherical shape. Both, the increase in the amount of the crosslinking agent and the presence of polyphenols, contributed to a more pronounced surface roughness of microbeads. The release of encapsulated polyphenols in simulated gastrointestinal fluids was prolonged to 3h. PMID:25037430

  4. Bacterial Growth on Chitosan-Coated Polypropylene Textile

    PubMed Central

    Erben, D.; Hola, V.; Jaros, J.; Rahel, J.

    2012-01-01

    Biofouling is a problem common in all systems where microorganisms and aqueous environment meet. Prevention of biofouling is therefore important in many industrial processes. The aim of this study was to develop a method to evaluate the ability of material coating to inhibit biofilm formation. Chitosan-coated polypropylene nonwoven textile was prepared using dielectric barrier discharge plasma activation. Resistance of the textile to biofouling was then tested. First, the textile was submerged into a growth medium inoculated with green fluorescein protein labelled Pseudomonas aeruginosa. After overnight incubation at 33°C, the textile was observed using confocal laser scanning microscopy for bacterial enumeration and biofilm structure characterisation. In the second stage, the textile was used as a filter medium for prefiltered river water, and the pressure development on the in-flow side was measured to quantify the overall level of biofouling. In both cases, nontreated textile samples were used as a control. The results indicate that the chitosan coating exhibits antibacterial properties. The developed method is applicable for the evaluation of the ability to inhibit biofilm formation. PMID:23724330

  5. Free-standing polyelectrolyte membranes made of chitosan and alginate

    PubMed Central

    Caridade, Sofia G.; Monge, Claire; Gilde, Flora; Boudou, Thomas; Mano, João F.; Picart, Catherine

    2014-01-01

    Free-standing films have increasing applications in the biomedical field as drug delivery systems, for wound healing and tissue engineering. Here, we prepared free-standing membranes by the layer-by-layer assembly of chitosan and alginate, two widely used biomaterials. Our aim was to produce thick membrane, to study the permeation of model drugs and the adhesion of muscle cells. We first defined the optimal growth conditions in terms of pH and alginate concentration. The membranes could be easily detached from polystyrene or polypropylene substrate without any post-processing step. They dry thickness was varied over a large range from 4 to 35 ?m. A two-fold swelling was observed by confocal microscopy when they were immersed in PBS. In addition, we quantified the permeation of model drugs (fluorescent dextrans) through the free standing membrane, which depended on the dextran molecular weight. Finally, we showed that myoblast cells exhibited a preferential adhesion on the alginate-ending membrane as compared to the chitosan-ending membrane or to the substrate side. PMID:23590116

  6. Chitosan coated liposomes as an innovative nanocarrier for drugs.

    PubMed

    Gonçalves, Manuela C F; Mertins, Omar; Pohlmann, Adriana R; Silveira, Nádya P; Guterres, Sílvia S

    2012-04-01

    Chitosomes are chitosan coated liposomes that represent an alternative to conventional liposomes since they present better stability and bioadhesivity. The aim of this work was to develop and evaluate the physico-chemical stability of melatonin (MEL)-loaded chitosomes as well as to compare their properties with that of MEL loaded liposomes. Structural characteristics of nanovesicles were also studied by dynamic light scattering and small angle X-ray scattering. The liposome and chitosome suspensions presented mean diameters between 150 nm and 254 nm, polydispersity indexes around 0.4, zeta potential values between -38 mV and -28 mV, pH values close to 4.0, MEL content close to 100% and encapsulation efficiency between 34.4% and 60.8%. Small angle X-rays scattering showed the presence of unilamelar structures, which were also observed by transmission electronic microscopy. Stability studies focusing on the particle diameter indicated that, within 90 days, the liposome suspensions had a decrease in mean diameter values and in polydispersity indexes, but no alterations were detected in zeta potentials and MEL content. The chitosome suspensions remained stable in relation to these parameters during 90 days. Multiple light scattering analysis (Turbiscan LAb) corroborated the the findings in the stability studies. The result sets pointed out the physico-chemical stability of chitosomes and the chitosan influence in their supramolecular structure. PMID:22515075

  7. Chitosan films: crosslinking with EDTA modifies physicochemical and mechanical properties.

    PubMed

    Singh, Kuldeep; Suri, Rajat; Tiwary, A K; Rana, Vikas

    2012-03-01

    The present study was aimed to develop chitosan-EDTA films and evaluate their physico-chemical and mechanical properties. The physical properties suggested lowest swelling, volume and volume index of films prepared by employing equal weight of chitosan (CH) and EDTA (1.5% w/v). The CH:EDTA film (1:l, on weight basis) showed minimum contact angle, work of adhesion and high negative spreading coefficient indicating lipophilic behavior of film. Further, the FTIR and DSC analysis suggested maximum crosslinking density in film prepared with equal proportion of CH and EDTA. The mechanical properties explored using texture analyzer revealed increasing the proportions of EDTA rendered the films more flexible and decreased their hardness. Furthermore, in vitro permeation of 5-FU and mesalamine with different solubilities showed minimum permeation across CH–EDTA (1:1) film, indicating high crosslinking density that decreased void space inside the film. Hence, the CH–EDTA conjugate could be considered to be possess great potential for various pharmaceutical applications such as film based delivery systems, controlled and sustained delivery systems etc. PMID:22286228

  8. Electrophoretic coating of amphiphilic chitosan colloids on regulating cellular behaviour

    PubMed Central

    Wang, Yen-Jen; Lo, Teng-Yuan; Wu, Chieh-Hsi; Liu, Dean-Mo

    2013-01-01

    In this communication, we report a facile nanotopographical control over a stainless steel surface via an electrophoretic deposition of colloidal amphiphilic chitosan for preferential growth, proliferation or migration of vascular smooth muscle cells (VSMCs) and human umbilical vein endothelial cells (HUVECs). Atomic force microscopy revealed that the colloidal surface exhibited a deposition time-dependent nanotopographical evolution, wherein two different nanotopographic textures indexed by ‘kurtosis’ (Rkur) value were easily designed, which were termed as ‘sharp’ (i.e. high peak-to-valley texture) surface and ‘flat’ (i.e. low peak-to-valley texture) surface. Cellular behaviour of VSMCs and HUVECs on both surfaces demonstrated topographically dependent morphogenesis, adherent responses and biochemical properties in comparison with bare stainless steel. The formation of a biofunctionalized surface upon a facile colloidal chitosan deposition envisions the potential application towards numerous biomedical devices, and this is especially promising for cardiovascular stents wherein a new surface with optimized texture can be designed and is expected to create an advantageous environment to stimulate HUVEC growth for improved healing performance. PMID:23804439

  9. Chitosan-Alginate Biocomposite Containing Fucoidan for Bone Tissue Engineering

    PubMed Central

    Venkatesan, Jayachandran; Bhatnagar, Ira; Kim, Se-Kwon

    2014-01-01

    Over the last few years, significant research has been conducted in the construction of artificial bone scaffolds. In the present study, different types of polymer scaffolds, such as chitosan-alginate (Chi-Alg) and chitosan-alginate with fucoidan (Chi-Alg-fucoidan), were developed by a freeze-drying method, and each was characterized as a bone graft substitute. The porosity, water uptake and retention ability of the prepared scaffolds showed similar efficacy. The pore size of the Chi-Alg and Chi-Alg-fucoidan scaffolds were measured from scanning electron microscopy and found to be 62–490 and 56–437 µm, respectively. In vitro studies using the MG-63 cell line revealed profound cytocompatibility, increased cell proliferation and enhanced alkaline phosphatase secretion in the Chi-Alg-fucoidan scaffold compared to the Chi-Alg scaffold. Further, protein adsorption and mineralization were about two times greater in the Chi-Alg-fucoidan scaffold than the Chi-Alg scaffold. Hence, we suggest that Chi-Alg-fucoidan will be a promising biomaterial for bone tissue regeneration. PMID:24441614

  10. Controlled release behaviors of chitosan/?, ?-glycerophosphate thermo-sensitive hydrogels

    NASA Astrophysics Data System (ADS)

    Liu, Wei-Fang; Kang, Chuan-Zhen; Kong, Ming; Li, Yang; Su, Jing; Yi, An; Cheng, Xiao-Jie; Chen, Xi-Guang

    2012-09-01

    Chitosan/?, ?-glycerophosphate (CS/?, ?-GP) thermo-sensitive hydrogels presented flowable solution state at low temperature and semisolid hydrogel when the ambient temperature increased. In this research, different concentrations of metronidazole encapsulated, CS and ?, ?-GP, as well as different acid solvents, were chosen to evaluate their influences on the drug release behaviors from CS/?, ?-GP hydrogels. It was found that there was a sustaining release during the first 3 h followed by a plateau. SEM images showed that drugs were located both on the surface and in the interior of hydrogels. The optimal preparation conditions of this hydrogel for drug release were as follows: 1.8% (w/v) CS in HAc solvent, 5.6% (w/v) ?, ?-GP and 5 g/L metronidazole encapsulation. Cytotoxicity evaluation found no toxic effect. In order to control the release rate, 2.5 g/L chitosan microspheres with spherical shape and smooth surface were incorporated, and it was found that the initial release process was alleviated, while drug concentration had no obvious effect on the release rate. It could be concluded that the metronidzole release behaviors could be optimized according to practical applications.

  11. Bacterial growth on chitosan-coated polypropylene textile.

    PubMed

    Erben, D; Hola, V; Jaros, J; Rahel, J

    2012-01-01

    Biofouling is a problem common in all systems where microorganisms and aqueous environment meet. Prevention of biofouling is therefore important in many industrial processes. The aim of this study was to develop a method to evaluate the ability of material coating to inhibit biofilm formation. Chitosan-coated polypropylene nonwoven textile was prepared using dielectric barrier discharge plasma activation. Resistance of the textile to biofouling was then tested. First, the textile was submerged into a growth medium inoculated with green fluorescein protein labelled Pseudomonas aeruginosa. After overnight incubation at 33°C, the textile was observed using confocal laser scanning microscopy for bacterial enumeration and biofilm structure characterisation. In the second stage, the textile was used as a filter medium for prefiltered river water, and the pressure development on the in-flow side was measured to quantify the overall level of biofouling. In both cases, nontreated textile samples were used as a control. The results indicate that the chitosan coating exhibits antibacterial properties. The developed method is applicable for the evaluation of the ability to inhibit biofilm formation. PMID:23724330

  12. Effect of quaternization degree on physiochemical and biological activities of chitosan from squid pens.

    PubMed

    Huang, Jun; Cheng, Zhen-Hua; Xie, Hai-Hua; Gong, Jin-Yan; Lou, Jian; Ge, Qing; Wang, Yong-Jiang; Wu, Yuan-Feng; Liu, Shi-Wang; Sun, Pei-Long; Mao, Jian-Wei

    2014-09-01

    Chitosan was prepared by alkaline N-deacetylation of ?-chitin from squid pens, and N-(2-hydroxy) propyl-3-trimethyl ammonium chitosan chloride (HTCC) derivatives, with different degrees of quaternization (DQ) ranging from 0.77 to 1.06, were synthesized. It was identified by FT-IR, 1H NMR and XRD analysis. All of the HTCC showed good water solubility in a wide pH range. The moisture absorption and retention abilities of all the HTCC were much better than that of the chitosan. The moisture absorption and retention values of all the HTCC at 43% RH for 24 h were above 49% and 92%, respectively. The scavenging ability of HTCC against hydroxyl and ABTS radicals improved with increasing concentration. The effectiveness of HTCC against hydroxyl radicals was lower than that of chitosan. These results indicated that HTCC, which has a much better moisture absorption and retention capacity, may act as a potential moisturizer in vitro. PMID:25077838

  13. Electrospun chitosan/sericin composite nanofibers with antibacterial property as potential wound dressings.

    PubMed

    Zhao, Rui; Li, Xiang; Sun, Bolun; Zhang, Ying; Zhang, Dawei; Tang, Zhaohui; Chen, Xuesi; Wang, Ce

    2014-07-01

    Chitosan and sericin are natural and low cost biomaterials. Both biomaterials displayed good compatibility to human tissues and antibacterial properties for biomedical application. In this study, we have successfully fabricated chitosan/sericin composite nanofibers by electrospinning. The obtained composite nanofibers were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) studies. The composite nanofibers had good morphology with diameter between 240nm and 380nm. In vitro methyl thiazolyl tetrazolium (MTT) assays demonstrated that the chitosan/sericin composite nanofibers were biocompatible and could promote the cell proliferation. Furthermore, the composite nanofibers showed good bactericidal activity against both of Gram-positive and Gram-negative bacteria. Thus, the chitosan/sericin composite nanofibers are promising for wound dressing applications. PMID:24769088

  14. Assessment of palmitoyl and sulphate conjugated glycol chitosan for development of polymeric micelles

    PubMed Central

    Ullah Khan, Ikram; Ayub, Gohar; Ranjha, Nazar M.

    2013-01-01

    Introduction:Amphiphilic copolymers are capable of forming core shell-like structures at the critical micellar concentration (CMC); hence, they can serve as drug carriers. Thus, in the present work, polymeric micelles based on novel chitosan derivative were synthesized. Methods:Block copolymer of palmitoyl glycol chitosan sulfate (PGCS) was prepared by grafting palmitoyl and sulfate groups serving as hydrophobic and hydrophilic fractions, respectively. Then, fourier transform infrared spectra (FTIR) and spectral changes in iodine/iodide mixture were carried out. Results:FTIR studies confirmed the formation of palmitoyl glycol chitosan sulfate (PGCS) and spectral changes in iodine/iodide mixture indicated CMC which lies in the range of 0.003-0.2 mg/ml. Conclusion: Therefore, our study indicated that polymeric micelles based on palmitoyl glycol chitosan sulphate could be used as a prospective carrier for water insoluble drugs. PMID:23878793

  15. Molecular dynamics simulation study of chitosan and gemcitabine as a drug delivery system.

    PubMed

    Razmimanesh, Fariba; Amjad-Iranagh, Sepideh; Modarress, Hamid

    2015-07-01

    By using molecular dynamics (MD) simulation, biodegradable biopolymer chitosan as a carrier for the drug gemcitabine was investigated and the effect of three initial drug concentrations (10, 40, and 80 %) on its loading efficiency was studied. Then water was added to the systems of drug and biopolymer and the effects of water on the interactions of drug and chitosan and on the drug loading efficiency were examined. From the results it was found that the maximum loading of the drug occurred at 40 % of the drug concentration. The radial distribution function calculations indicated that in the absence of water molecules, the drug molecules were located at shorter distance from chitosan and the loading efficiency of the drug in these systems was higher. Graphical Abstract Chitosan and gemcitabine. PMID:26044358

  16. Comparison of chitosan/starch composite film properties before and after cross-linking.

    PubMed

    Li, Haihong; Gao, Xiaochen; Wang, Yan; Zhang, Xiaobo; Tong, Zhiwei

    2013-01-01

    Unmodified and cross-linked chitosan/starch composite films were prepared using the solvent evaporation method. The properties of the films were studied to obtain useful information about the possible applications of composite films. FT-IR, SEM, and swelling property investigations show that the cross-linking agent glutaraldehyde reacts in the chitosan and starch blend. The compatibility of chitosan and starch blends before and after cross-linking was studied by UV-vis spectroscopy. The compatibility of the blends deteriorated after cross-linking. This finding was confirmed by the results of mechanical properties. The films show improved water barrier performance after cross-linking. The use of trace concentrations of glutaraldehyde in chitosan/starch films allows for possible application in the biomedical field. PMID:23107802

  17. Application of Spectroscopic Methods for Structural Analysis of Chitin and Chitosan

    PubMed Central

    Kumirska, Jolanta; Czerwicka, Ma?gorzata; Kaczy?ski, Zbigniew; Bychowska, Anna; Brzozowski, Krzysztof; Thöming, Jorg; Stepnowski, Piotr

    2010-01-01

    Chitin, the second most important natural polymer in the world, and its N-deacetylated derivative chitosan, have been identified as versatile biopolymers for a broad range of applications in medicine, agriculture and the food industry. Two of the main reasons for this are firstly the unique chemical, physicochemical and biological properties of chitin and chitosan, and secondly the unlimited supply of raw materials for their production. These polymers exhibit widely differing physicochemical properties depending on the chitin source and the conditions of chitosan production. The presence of reactive functional groups as well as the polysaccharide nature of these biopolymers enables them to undergo diverse chemical modifications. A complete chemical and physicochemical characterization of chitin, chitosan and their derivatives is not possible without using spectroscopic techniques. This review focuses on the application of spectroscopic methods for the structural analysis of these compounds. PMID:20559489

  18. [Purification of superoxide dismutase from blood erythrocyte by nano magnetic chitosan microspheres].

    PubMed

    Wang, Baoquan; Ping, Juan; Li, Feng; Zhang, Yongzhou; Liu, Cui; Pang, Xiaobin

    2014-06-01

    Nano magnetic microspheres prepared by chitosan and poly acylic acid were applied to purifying superoxide dismutase from blood erythrocyte. Chitosan-polyacyilc acid graft copolymer was synthesized by free radical graft copolymerization with potassium persulfate as inititator. To prepare Fe3O4 magnetic fluids with chemical coprecipitation, chitosan-polyacylic nano magnetic microspheres were prepared with glutaraldehyde as crosslinking agent. Structure of nano magnetic microspheres was detected by FT-IR spectrometer. Particle size and morphology were characterized by JEM-4000EX technology. Chitosan-polyacylic nanometer microspheres have good paticle cize distribution, magnetic responsiveness and protein adsoption. Activity, product yield and activity recovery of SOD after purification reached 6 727 U/mg, 21.1%, and 85.7% respectively. Purification of blood superoxide dismutase by chistosan-polyacylic acid microspheres has its renewable and feasible nature. PMID:25212016

  19. Processing/formulation parameters determining dispersity of chitosan particles: an ANNs study.

    PubMed

    Esmaeilzadeh-Gharehdaghi, Elina; Faramarzi, Mohammad Ali; Amini, Mohammad Ali; Moazeni, Esmaeil; Amani, Amir

    2014-01-01

    Although a great number of studies may be found in literature about the parameters affecting the size of chitosan nanoparticles, no systematic work so far has detailed the factors affecting the polydispersity of chitosan as an important factor determining the quality of many preparations. Herein, using artificial neural networks (ANNs), four independent variables, namely, pH and concentration of chitosan solution as well as time and amplitude of sonication of the solution were studied to determine their influence on the polydispersity of solution. We found that in an ultrasound prepared nanodispersion of chitosan, all the four input parameters have reverse but non-linear relation with the polydispersity of the nanoparticles. PMID:23795904

  20. Three dimensional chitosan scaffolds influence the extra cellular matrix expression in Schwann cells.

    PubMed

    Lin, Chuang-Yu; Li, Li-Tzu; Su, Wen-Ta

    2014-09-01

    Chitosan is a choice material for scaffolds in regenerative medicine. One of the applications is to bridge the damaged peripheral nerves. Previous studies showed that combination of chitosan conduits and cultured Schwann cells could increase the opportunity for re-connection of broken nerves. It has also been known that Schwann cells can produce the ECM components which are critical for nerve regeneration. In this study, we used the rat Schwann cells (RSCs) grown on porous chitosan scaffolds for quantitative analysis of ECM protein expression. The RSCs grown on chitosan scaffolds secreted higher amount of laminin and collagen 4 than those grown on the plane. The increased laminin and collagen 4 produced by Schwann cells could create a preferable condition for stimulating peripheral nerve regeneration. PMID:25063144

  1. Properties and Biocompatibility of Chitosan and Silk Fibroin Blend Films for Application in Skin Tissue Engineering

    PubMed Central

    Luangbudnark, Witoo; Viyoch, Jarupa; Laupattarakasem, Wiroon; Surakunprapha, Palakorn; Laupattarakasem, Pisamai

    2012-01-01

    Chitosan/silk fibroin (CS/SF) blend films were prepared and evaluated for feasibility of using the films as biomaterial for skin tissue engineering application. Fourier transform infrared spectroscopy and differential scanning calorimetry analysis indicated chemical interaction between chitosan and fibroin. Chitosan enhanced ?-sheet conformation of fibroin and resulted in shifting of thermal degradation of the films. Flexibility, swelling index, and enzyme degradation were also increased by the chitosan content of the blend films. Biocompatibility of the blend films was determined by cultivation with fibroblast cells. All films showed no cytotoxicity by XTT assay. Fibroblast cells spread on CS/SF films via dendritic extensions, and cell-cell interactions were noted. Cell proliferation on CS/SF films was also demonstrated, and their phenotype was examined by the expression of collagen type I gene. These results showed possibility of using the CS/SF films as a supporting material for further study on skin tissue engineering. PMID:22701367

  2. Chitosan-coated gold nanorods for cancer therapy combining chemical and photothermal effects.

    PubMed

    Duan, Ruiping; Zhou, Zhimin; Su, Guanghao; Liu, Lingrong; Guan, Man; Du, Bo; Zhang, Qiqing

    2014-08-01

    To develop a novel type of nanoparticle for cancer therapy, gold nanorods (GNRs) are coated with chitosan (CS) derivatives to combine chemical and photothermal effects. Thiol-modified chitosan derivatives chemically conjugated to doxorubicin (DOX) are successfully synthesized and their in vitro effect is evaluated. Functional nanocarriers (DOX-CS-GNR) with good biocompatibility and optical properties are prepared by conjugating chitosan derivatives to GNRs. Two types of structures with different molar ratios of chitosan derivatives and GNRs are successfully obtained. In in vitro studies, GNR-loaded nanoparticles show low cytotoxicity and high potential for anti-cancer effects. Under conditions of short exposure time and low light intensity, DOX-CS-GNR nanocarriers with a side-by-side structure exhibit cytoxicity against tumor cells based on a combination of chemical and photothermal therapeutic effects. PMID:24789052

  3. Curcumin-containing liposomes stabilized by thin layers of chitosan derivatives.

    PubMed

    Karewicz, Anna; Bielska, Dorota; Loboda, Agnieszka; Gzyl-Malcher, Barbara; Bednar, Jan; Jozkowicz, Alicja; Dulak, Jozef; Nowakowska, Maria

    2013-09-01

    Stable vesicles for efficient curcumin encapsulation, delivery and controlled release have been obtained by coating of liposomes with thin layer of newly synthesized chitosan derivatives. Three different derivatives of chitosan were obtained and studied: the cationic (by introduction of the stable, quaternary ammonium groups), the hydrophobic (by attachment of N-dodecyl groups) and cationic-hydrophobic one (containing both quaternary ammonium and N-dodecyl groups). Zeta potential measurements confirmed effective coating of liposomes with all these chitosan derivatives. The liposomes coated with cationic-hydrophobic chitosan derivative are the most promising curcumin carriers; they can easily penetrate cell membrane and release curcumin in a controlled manner. Biological studies indicated that such systems are non-toxic for murine fibroblasts (NIH3T3) while toxic toward murine melanoma (B16F10) cell line. PMID:23668985

  4. Application of spectroscopic methods for structural analysis of chitin and chitosan.

    PubMed

    Kumirska, Jolanta; Czerwicka, Ma?gorzata; Kaczy?ski, Zbigniew; Bychowska, Anna; Brzozowski, Krzysztof; Thöming, Jorg; Stepnowski, Piotr

    2010-01-01

    Chitin, the second most important natural polymer in the world, and its N-deacetylated derivative chitosan, have been identified as versatile biopolymers for a broad range of applications in medicine, agriculture and the food industry. Two of the main reasons for this are firstly the unique chemical, physicochemical and biological properties of chitin and chitosan, and secondly the unlimited supply of raw materials for their production. These polymers exhibit widely differing physicochemical properties depending on the chitin source and the conditions of chitosan production. The presence of reactive functional groups as well as the polysaccharide nature of these biopolymers enables them to undergo diverse chemical modifications. A complete chemical and physicochemical characterization of chitin, chitosan and their derivatives is not possible without using spectroscopic techniques. This review focuses on the application of spectroscopic methods for the structural analysis of these compounds. PMID:20559489

  5. Development of edible bioactive coating based on modified chitosan for increasing shelf life of strawberries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For increasing the shelf life of strawberries during storage, bioactive coatings were applied using modified polysaccharides of chitosan. First, antimicrobial tests were performed with selected essential oils to evaluate their antimicrobial capacities against moulds and total flora isolated from str...

  6. Effect of Chitosan on the Induction of DNA Damage Response by Selenium Compounds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium (Se), a nutrient trace mineral, plays important roles in optimizing human health. Chitosan is an effective, natural-oriented material for synthesizing nanopolymers, with preferable properties such as biocompatibility, biodegradation and resistance to certain enzymes. In this study, encapsul...

  7. Improved barrier and mechanical properties of novel hydroxypropyl methylcellulose edible films with chitosan/tripolyphosphate nanoparticles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chitosan/tripolyphosphate nanoparticles were prepared and incorporated in hydroxypropyl methylcellulose (HPMC) films. FT-IR and transmission electron microscopy (TEM) analyses of the nanoparticles, mechanical properties, water vapor permeability, thermal stability, scanning electron microscopy (SEM...

  8. Preparation and physical/electrochemical characterization of carbon nanotube-chitosan modified pencil graphite electrode

    NASA Astrophysics Data System (ADS)

    Vural, Tayfun; Kuralay, Filiz; Bayram, Cem; Abaci, Serdar; Denkbas, Emir Baki

    2010-11-01

    In this work, preparation and characterization of single-walled carbon nanotube-chitosan (SWNT-chitosan) modified disposable pencil graphite electrode (PGE) was carried out. Firstly, commercial single-walled carbon nanotube was purified and characterized using thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and energy dispersive analysis of X-ray (EDX) for this purpose. Purified SWNT was mixed with chitosan polymer for preparing their composite. Then, PGE was modified with this composite. The characterization of the modified electrode was carried out using atomic force microscopy (AFM). The electrochemical behaviour of the obtained electrode was investigated and compared with the electrochemical behaviour of chitosan modified and unmodified PGEs using cyclic voltammetry (CV), differential pulse voltammetry (DPV) and alternative current (AC) impedance spectroscopy. In order to obtain more sensitive electrochemical signals, the effect of SWNT concentration was studied. This modified electrode also showed electrocatalytic effect for hydrogen evolution.

  9. Preservation properties of in situ modified CaCO3-chitosan composite coatings.

    PubMed

    Sun, Tong; Hao, Wen-ting; Li, Jian-rong; Dong, Zhi-jian; Wu, Chao-ling

    2015-09-15

    To improve the dispersibility, hydrophilia constraints of primitive particle size, and reduce the economic cost, in situ modified CaCO3-chitosan composite coatings were prepared by tape-casting with different modifiers. The coating structures were characterised, and the preservation properties of the coatings were evaluated by fresh indices of Sciaenops ocellatus. The results revealed that the coatings were homogeneous and compact when the in situ modifier was sodium stearate. Besides, the amide I group of chitosan disappeared and hydrogen bonds were formed between the nano-CaCO3 and the chitosan. Meanwhile, the preservation effects to S. ocellatus of the coatings modified in situ by sodium stearate and sodium citrate were better. This was because the coatings effectively prevented oxygen and bacteria from reaching S. ocellatus, and thus inhibited the degradation of the proteins and lipids. The in situ modified method is conducive to chitosan coating properties, which will be widely used in the food preservation field. PMID:25863631

  10. Synthesis and anti-fungal effect of silver nanoparticles–chitosan composite particles

    PubMed Central

    Wang, Lung-Shuo; Wang, Chih-Yu; Yang, Chih-Hui; Hsieh, Chen-Ling; Chen, Szu-Yu; Shen, Chi-Yen; Wang, Jia-Jung; Huang, Keng-Shiang

    2015-01-01

    Silver nanoparticles have been used in various fields, and several synthesis processes have been developed. The stability and dispersion of the synthesized nanoparticles is vital. The present article describes a novel approach for one-step synthesis of silver nanoparticles–embedded chitosan particles. The proposed approach was applied to simultaneously obtain and stabilize silver nanoparticles in a chitosan polymer matrix in-situ. The diameter of the synthesized chitosan composite particles ranged from 1.7 mm to 2.5 mm, and the embedded silver nanoparticles were measured to be 15±3.3 nm. Further, the analyses of ultraviolet-visible spectroscopy, energy dispersive spectroscopy, and X-ray diffraction were employed to characterize the prepared composites. The results show that the silver nanoparticles were distributed over the surface and interior of the chitosan spheres. The fabricated spheres had macroporous property, and could be used for many applications such as fungicidal agents in the future. PMID:25878501

  11. Novel atmospheric plasma enhanced chitosan nanofiber/gauze composite wound dressings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Electrospun chitosan nanofibers were deposited onto atmospheric plasma treated cotton gauze to create a novel composite bandage with higher adhesion, better handling properties, enhanced bioactivity, and moisture management. Plasma treatment of the gauze substrate was performed to improve the durabi...

  12. Synthesis and adsorption properties of chitosan-silica nanocomposite prepared by sol-gel method.

    PubMed

    Budnyak, Tetyana M; Pylypchuk, Ievgen V; Tertykh, Valentin A; Yanovska, Elina S; Kolodynska, Dorota

    2015-01-01

    A hybrid nanocomposite material has been obtained by in situ formation of an inorganic network in the presence of a preformed organic polymer. Chitosan biopolymer and tetraethoxysilane (TEOS), which is the most common silica precursor, were used for the sol-gel reaction. The obtained composite chitosan-silica material has been characterized by physicochemical methods such as differential thermal analyses (DTA); carbon, hydrogen, and nitrogen (CHN) elemental analysis; nitrogen adsorption/desorption isotherms, scanning electron microscopy (SEM); and Fourier transform infrared (FTIR) spectroscopy to determine possible interactions between silica and chitosan macromolecules. Adsorption of microquantities of V(V), Mo(VI), and Cr(VI) oxoanions from the aqueous solutions by the obtained composite has been studied in comparison with the chitosan beads, previously crosslinked with glutaraldehyde. The adsorption capacity and kinetic sorption characteristics of the composite material were estimated. PMID:25852383

  13. Novel anti-infective activities of chitosan immobilized titanium surface with enhanced osteogenic properties.

    PubMed

    Ghimire, Niranjan; Luo, Jie; Tang, Ruogu; Sun, Yuyu; Deng, Ying

    2014-10-01

    We have covalently immobilized chitosan onto a titanium (Ti) surface to manage implant-related infection and poor osseointegration, two of the major complications of orthopedic implants. The Ti surface was first treated with sulfuric acid (SA) and then covalently grafted with chitosan. Surface roughness, contact angle and surface zeta potential of the samples were markedly increased by the sulfuric acid treatment and the subsequent chitosan immobilization. The chitosan-immobilized Ti (SA-CS-Ti) showed two novel antimicrobial roles: it (a) prevented the invasion and internalization of bacteria into the osteoblast-like cells, and (b) significantly increased the susceptibility of adherent bacteria to antibiotics. In addition, the sulfuric acid-treated Ti (SA-Ti) and SA-CS-Ti led to significantly increased (P<0.05) osteoblast-like cell attachment, enhanced cell proliferation, and better osteogenic differentiation and mineralization of osteoblast-like cells. PMID:25033432

  14. Innovative thermoplastic chitosan obtained by thermo-mechanical mixing with polyol plasticizers.

    PubMed

    Matet, Marie; Heuzey, Marie-Claude; Pollet, Eric; Ajji, Abdellah; Avérous, Luc

    2013-06-01

    Chitosan shows a degradation temperature lower than its melting point, which prevents its development in several applications. One way to overcome this issue is the plasticization of the carbohydrate. In this work plasticized chitosan was prepared by a thermo-mechanical kneading approach. The effects of different non-volatile polyol plasticizers (glycerol, xylitol and sorbitol) were investigated. The microstructure and morphology were determined using FTIR, XRD, TEM and SEM in order to understand the plasticization mechanism. Sorbitol, which is the highest molecular weight polyol used, resulted in plasticized chitosan with the highest thermal, mechanical and rheological properties. On the other hand, the sample plasticized with glycerol, the lowest molecular weight polyol, had the most important amorphous phase content and the lowest thermal, mechanical and rheological properties. Also, when the polyol content increased in the formulation, the plasticized chitosan was more amorphous and consequently its processability easier, while its properties decreased. PMID:23618266

  15. Electrospinning of curcumin loaded chitosan/poly (lactic acid) nanofilm and evaluation of its medicinal characteristics

    NASA Astrophysics Data System (ADS)

    Dhurai, Bhaarathi; Saraswathy, Nachimuthu; Maheswaran, Ramasamy; Sethupathi, Ponnusamy; Vanitha, Palanisamy; Vigneshwaran, Sukumar; Rameshbabu, Venugopal

    2013-12-01

    The curcumin loaded chitosan/poly (lactic acid) (PLA) nanofibers were produced using electrospinning. Box—Behnken experimental design was used for the optimization of variables (-1, 0, + 1 coded level) like chitosan/PLA strength (% w/v), curcumin strength (% w/v) and applied voltage (kV) to obtain uniform fiber diameter. The morphology of nanofibers was shown by SEM. Molecular interactions and the presence of each chemical compound of curcumin loaded chitosan/PLA fibers were characterized by FTIR and EDX analysis. Antioxidant, drug release and in vitro cytotoxicity tests were performed to evaluate the suitability of nanofibers that would be used for wound healing. In vivo wound healing studies on excision and incision wounds created on rat model showed significant reduction of wound area when compared to untreated. The better healing efficiency can be attributed to the presence of curcumin and chitosan.

  16. Recent Modifications of Chitosan for Adsorption Applications: A Critical and Systematic Review

    PubMed Central

    Kyzas, George Z.; Bikiaris, Dimitrios N.

    2015-01-01

    Chitosan is considered to be one of the most promising and applicable materials in adsorption applications. The existence of amino and hydroxyl groups in its molecules contributes to many possible adsorption interactions between chitosan and pollutants (dyes, metals, ions, phenols, pharmaceuticals/drugs, pesticides, herbicides, etc.). These functional groups can help in establishing positions for modification. Based on the learning from previously published works in literature, researchers have achieved a modification of chitosan with a number of different functional groups. This work summarizes the published works of the last three years (2012–2014) regarding the modification reactions of chitosans (grafting, cross-linking, etc.) and their application to adsorption of different environmental pollutants (in liquid-phase). PMID:25584681

  17. The processing of chitosan and its derivatives and their application for postoperative anti-adhesion.

    PubMed

    Zhu, Lin; Peng, Lin; Zhang, Yu-Qing

    2015-01-01

    The formation of peritoneal adhesions represents one of the most common complications after abdominal surgery, and it increases the difficulty of re-operation. Thus, preventing postoperative adhesions is a major problem in the field of surgical medicine. Due to a lack of good predictive animal models and the complexity of adhesion pathogenesis, attempts to prevent or reduce peritoneal adhesions have been largely unsuccessful. As a result, the study of anti-adhesion drugs and materials has become a hot topic for experts and scholars. The processing and development of chitosan and its derivatives as new anti-adhesion materials is highly valued because chitosan is inexpensive, highly biocompatible, and not cytotoxic, making it a promising anti-adhesion material. Here, we review the sources and preparation of chitosan and the progress made toward producing different types of chitosan and its derivatives for preventing adhesion. PMID:25723456

  18. Coalescence of Extracellular Matrix (ECM) from Porcine Urinary Bladder (UBM) with a Laser-Activated Chitosan-Based Surgical Adhesive

    Microsoft Academic Search

    Tania Ahmed; Helder Marçal; Scott Johnson; Bryan N. Brown; L. John R. Foster

    2012-01-01

    Urinary bladder matrix (UBM) has been extensively investigated as a naturally occurring biomaterial in therapeutic applications for tissue repair or regeneration, while other strategies involve biopolymers such as chitosan for tissue reconstruction. The coalescence of UBM with chitosan has considerable potential in enhancing tissue reconstruction. Characterisation of a novel, laser-activated, chitosan-based, thin-film surgical adhesive with UBM in various morphologies showed

  19. Chitosan-based microcapsules containing grapefruit seed extract grafted onto cellulose fibers by a non-toxic procedure

    Microsoft Academic Search

    Diana Alonso; Miquel Gimeno; José D. Sepúlveda-Sánchez; Keiko Shirai

    2010-01-01

    A novel non-toxic procedure is described for the grafting of chitosan-based microcapsules containing grapefruit seed oil extract onto cellulose. The cellulose was previously UV-irradiated and then functionalized from an aqueous emulsion of the chitosan with the essential oil. The novel materials are readily attained with durable fragrance and enhanced antimicrobial properties. The incorporation of chitosan as determined from the elemental

  20. The effect of size and acetylation degree of chitosan derivatives on tobacco plant protection against Phytophthora parasitica nicotianae

    Microsoft Academic Search

    Alejandro B. Falcón; Juan Carlos Cabrera; Daimy Costales; Miguel Angel Ramírez; Gustavo Cabrera; Verónica Toledo; Miguel Angel Martínez-Téllez

    2008-01-01

    Enzymatic degradation of chitosan polymer with Pectinex Ultra SPL was used to obtain derivatives with biological potential\\u000a as protective agents against Phytophthora parasitica nicotianae (Ppn) in tobacco plants. The 24 h hydrolysate showed the highest Ppn antipathogenic activity and the chitosan native polymer the lowest. The in vitro growth inhibition of several Phytophthora parasitica strains by two chitosans of different DA was

  1. Physicochemical properties of edible films from chitosan composites obtained by microwave heating

    Microsoft Academic Search

    G. Cárdenas; J. Díaz; M. F. Meléndrez; C. Cruzat

    2008-01-01

    Summary  Chitosan films were prepared by casting, using microwave and dried by air convection. No scientific literature covers the\\u000a use of microwave heating in the preparation of chitosan films by casting technique. Effects of heating time, molecular weight\\u000a and plasticizer on structure, thermal behavior, surface, barrier properties and light transmission were investigated. Heating\\u000a time showed that the microwave heating did not

  2. BIOSORPTION OF METAL IONS USING CHITOSAN, CHITIN, AND BIOMASS OF RHIZOPUS ORYZAE

    Microsoft Academic Search

    Brenda J. Mcafee; W. Douglas Gould; Jennifer C. Nadeau; Antonio C. A. da Costa

    2001-01-01

    The biosorptive capacity of dried biomass fungus Rhizopus oryzae Went & Prinsen-Geerlings for metal sorption was compared with commercially available sources of chitin, chitosan and chitosan cross-linked with benzoquinone. Initial pH of the metal solution significantly influenced metal uptake capacity. The optimum biomass\\/solution ratio for metal uptake in all systems was 1 g\\/L. The highest metal uptake values (137, 108,

  3. Thiolated chitosan-modified PLA-PCL-TPGS nanoparticles for oral chemotherapy of lung cancer

    NASA Astrophysics Data System (ADS)

    Jiang, Liqin; Li, Xuemin; Liu, Lingrong; Zhang, Qiqing

    2013-02-01

    Oral chemotherapy is a key step towards `chemotherapy at home', a dream of cancer patients, which will radically change the clinical practice of chemotherapy and greatly improve the quality of life of the patients. In this research, three types of nanoparticle formulation from commercial PCL and self-synthesized d-?-tocopheryl polyethylene glycol 1000 succinate (PLA-PCL-TPGS) random copolymer were prepared in this research for oral delivery of antitumor agents, including thiolated chitosan-modified PCL nanoparticles, unmodified PLA-PCL-TPGS nanoparticles, and thiolated chitosan-modified PLA-PCL-TPGS nanoparticles. Firstly, the PLA-PCL-TPGS random copolymer was synthesized and characterized. Thiolated chitosan greatly increases its mucoadhesiveness and permeation properties, thus increasing the chances of nanoparticle uptake by the gastrointestinal mucosa and improving drug absorption. The PLA-PCL-TPGS nanoparticles were found by FESEM that they are of spherical shape and around 200 nm in diameter. The surface charge of PLA-PCL-TPGS nanoparticles was reversed from anionic to cationic after thiolated chitosan modification. The thiolated chitosan-modified PLA-PCL-TPGS nanoparticles have significantly higher level of the cell uptake than that of thiolated chitosan-modified PLGA nanoparticles and unmodified PLA-PCL-TPGS nanoparticles. In vitro cell viability studies showed advantages of the thiolated chitosan-modified PLA-PCL-TPGS nanoparticles over Taxol® in terms of cytotoxicity against A549 cells. It seems that the mucoadhesive nanoparticles can increase paclitaxel transport by opening tight junctions and bypassing the efflux pump of P-glycoprotein. In conclusion, PLA-PCL-TPGS nanoparticles modified by thiolated chitosan could enhance the cellular uptake and cytotoxicity, which revealed a potential application for oral chemotherapy of lung cancer.

  4. Metachromatic behavior: Influence of the molecular weights of chitosan in thionine-sodium dodecyl sulfate system

    Microsoft Academic Search

    Sung-Hyun Kim

    2009-01-01

    Chitosans having three molecular weights (4.0×104, 8.0×104, and 16.0×104Da) were isolated by an ultrasonic degradation of chitin obtained from crab shell wastes and used to determine a metachromic behavior from the effect of aggregation characteristics. The metachromatic behaviors of thionine (Th)-sodium dodecyl sulfate (SDS), Th-SDS-chitosan system were investigated by the absorption and fluorescence spectroscopy.For SDS\\/Th<40, the order of decrease of

  5. Correlating Physicochemical Properties of Boronic Acid-Chitosan Conjugates to Glucose Adsorption Sensitivity

    PubMed Central

    Asantewaa, Yaa; Aylott, Jonathan; Burley, Jonathan C.; Billa, Nashiru; Roberts, Clive J.

    2012-01-01

    Phenyl boronic acid (PBA), which is known to interact with glucose, was covalently bonded to chitosan by direct reductive N-alkylation of chitosan with 4-formylphenylboronic acid (4-FPBA). Evidence of PBA bonding on chitosan was assessed by FTIR, ToF-SIMS, SEM, DSC and glucose adsorption sensitivity measurements. FTIR spectra showed strong signals at 1560 and 630 cm?1 indicating the formation of p-substituted benzene. Similarly, ToF-SIMS analyses on the conjugates registered fragments of boron ion (B?) at 11.0 m/z whose intensity increased in proportion to 4-FPBA loading. The degree to which PBA was bonded to chitosan was related to the 4-FPBA load used in the reaction (termed F1 through to F6 with increasing 4-FPBA load). Glucose adsorption sensitivity to PBA-bonded chitosan was directly related to the amount of PBA functionality within the conjugates and the physical nature of the matrices (porous or crystalline). Topographic analysis by SEM revealed that PBA-chitosan conjugates F1, F2 and F3 have porous matrices and their sensitivity to glucose adsorption was directly proportional to the degree of PBA substitution onto chitosan. Conversely, conjugates F4, F5 and F6 appeared crystalline under SEM and glucose adsorption sensitivity decreased in proportion to amount of PBA bonded to chitosan. The crystalline nature of the conjugates was confirmed by DSC, where the exothermic event related to the melting of the bonded PBA moiety, occurred at 338 °C. Thus, decreased sensitivity to glucose adsorption by the conjugates can be ascribed to the crystallinity imparted by increased content of the bonded PBA moiety, providing an optimal loading of PBA in terms of maximizing response to glucose. PMID:24300397

  6. Preparation and characterization of N-methylene phosphonic and quaternized chitosan composite membranes for electrolyte separations

    Microsoft Academic Search

    Arunima Saxena; Arvind Kumar; Vinod K. Shahi

    2006-01-01

    Chitosan was functionalized either by introducing a phosphonic acid group or by quaternization of existing primary ammonium groups in order to make it a water-soluble material. Functionalized chitosans and poly(vinyl alcohol) (PVA)-based nanoporous charged membranes were prepared in aqueous media and gelated in methanol at 10?°C to tailor their pore structure. These membranes were extensively characterized for their physicochemical, electrochemical,

  7. Development and characterization of chitosan and phosphomolybdic acid (PMA) based composites

    Microsoft Academic Search

    R. K. Mishra; S. Mondal; M. Datt; Ajit K. Banthia

    2010-01-01

    This work reports the development and characterization of chitosan\\/Phosphomolybdic acid (PMA) based composite membranes. The\\u000a prepared composite membranes were characterized by FTIR (Fourier transform infrared) spectroscopy, X ray diffraction (XRD),\\u000a differential scanning calorimetry (DSC), tensile strength test, and thermogravimetric analysis (TGA). FTIR spectroscopy indicated\\u000a the proper molecular interactions between chitosan and PMA. XRD spectroscopy indicated the semi crystalline nature of

  8. Synthesis, characterization and cytotoxicity of poly(ethylene glycol)-graft-trimethyl chitosan block copolymers

    Microsoft Academic Search

    Shirui Mao; Xintao Shuai; Florian Unger; Matthias Wittmar; Xiulan Xie; Thomas Kissel

    2005-01-01

    PEGylated trimethyl chitosan (TMC) copolymers were synthesized in an attempt to both increase the solubility of chitosan in water, and improve the biocompatibility of TMC. A series of copolymers with different degrees of substitution were obtained by grafting activated poly(ethylene glycol)s (PEG) of different MW onto TMC via primary amino groups. Structure of the copolymers was characterized using 1H, 13C

  9. Metal uptake by chitosan derivatives and structure studies of the polymer metal complexes

    Microsoft Academic Search

    Adel A. A. Emara; Mohamed A. Tawab; M. A. El-ghamry; Maher Z. Elsabee

    2011-01-01

    Two modified chitosan polymers were obtained by reaction of chitosan with cinnamoyl chloride and cinnamoyl isothiocyanate to produce two new derivatives. The new modified polymers were characterized by elemental and spectral analysis to confirm their structures. Their metal up take capacity was investigated both under competitive and noncompetitive conditions. At pH 5.6, the (ChitoCin and ChitoThioCin) polymers exhibit higher capacity

  10. Self-assembled nanoparticles based on linoleic-acid modified chitosan: Stability and adsorption of trypsin

    Microsoft Academic Search

    Chen-Guang Liu; Xi-Guang Chen; Hyun-Jin Park

    2005-01-01

    The hydrogel nanoparticles can be prepared using linoleic modified chitosan following sonication. The morphology and size distribution of nanoparticles were determined by AFM and photocorrelation spectroscopy, respectively. The effects of environment factors on particle size and adsorption of trypsin (TR) were also analyzed. The LA-chitosan nanoparticles were in the range of 200–600nm with satisfactory structural integrity. The particle size slightly

  11. Orange juices enriched with chitosan: Optimisation for extending the shelf-life

    Microsoft Academic Search

    Ana B. Martín-Diana; Daniel Rico; J. M. Barat; Catherine Barry-Ryan

    2009-01-01

    Optimisation of the incorporation of chitosan in orange juice was accomplished by the evaluation of quality and nutritional markers. Response surface methodology was applied to obtain quadratic and second degree response surface model equations. The analyses showed that increases in chitosan concentration extended the quality of the orange juice significantly (p<0.05), reducing enzymatic and non-enzymatic browning and controlling the spoilage

  12. Antibacterial activity of quaternary ammonium chitosan containing mono or disaccharide moieties: Preparation and characterization

    Microsoft Academic Search

    Warayuth Sajomsang; Pattarapond Gonil; Supawan Tantayanon

    2009-01-01

    The 9 quaternary ammonium chitosans containing monosaccharides or disaccharides moieties were successfully synthesized by reductive N-alkylation then quaternized by N-(3-chloro-2-hydroxypropyl) trimethylammonium chloride (Quat-188). The chemical structures of quaternary ammonium chitosan derivatives were characterized by ATR-FTIR and 1H NMR spectroscopy. The degree of N-substitution (DS) and the degree of quaternization (DQ) were determined by 1H NMR spectroscopic method. It was found

  13. A series of novel chitosan derivatives: Synthesis, characterization and micellar solubilization of paclitaxel

    Microsoft Academic Search

    Zhong Yao; Can Zhang; Qineng Ping

    2007-01-01

    A series of novel chitosan derivatives with octyl, sulfate and polyethylene glycol monomethyl ether (mPEG) groups as hydrophobic and hydrophilic moieties, respectively, were synthesized. These PEGylated amphiphilic chitosan derivatives were characterized with 1H NMR, 13C NMR, FTIR and elemental analysis. And their physical properties were measured by wide angle X-ray diffraction (WAXD) and thermogravimetric analysis (TG). The critical micelle concentrations

  14. Novel biocompatible composite (Chitosan–zinc oxide nanoparticle): Preparation, characterization and dye adsorption properties

    Microsoft Academic Search

    Raziyeh Salehi; Mokhtar Arami; Niyaz Mohammad Mahmoodi; Hajir Bahrami; Shooka Khorramfar

    2010-01-01

    In this paper, the preparation, characterization and dye adsorption properties of novel biocompatible composite (Chitosan–zinc oxide nanoparticle) (CS\\/n-ZnO) were investigated. Zinc oxide nanoparticles were immobilized onto Chitosan. Physical characteristics of CS\\/n-ZnO were studied using Fourier transform infra-red (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and wavelength dispersive X-ray spectroscopy (WDX). Two textile dyes, Direct Blue 78 (DB78) and Acid

  15. Preparation of porous chitosan gel beads for copper(II) ion adsorption

    Microsoft Academic Search

    Fan Zhao; Binyu Yu; Zhengrong Yue; Ting Wang; Xian Wen; Zongbin Liu; Changsheng Zhao

    2007-01-01

    In this paper, chitosan porous beads were prepared by using a phase inversion technique, and then used for the adsorption and removal of copper(II) ions. The porosity, diameter and other characteristics were characterized. With the increase of chitosan and NaOH concentration used to prepare the beads, the amount of adsorbed Cu2+ per gram of the beads decreased. A maximum adsorption

  16. Transcriptional Response of Saccharomyces cerevisiae to the Plasma Membrane-Perturbing Compound Chitosan

    Microsoft Academic Search

    Anna Zakrzewska; Andre Boorsma; Klaas J. Hellingwerf; Frans M. Klis

    2005-01-01

    Chitosan is a plasma membrane-perturbing compound consisting of linear chains of ?-1,4-linked glucosamine residues, which at acidic pHs become positively charged. It is extensively used as an antimicrobial compound, yet its mode of action is still unresolved. Chitosan strongly affected the growth of the yeast Saccharomyces cerevisiae, the food spoilage yeast Zygosaccharomyces bailii, and two human-pathogenic yeasts, Candida albicans and

  17. Interaction of anionic collagen with chitosan: Effect on thermal and morphological characteristics

    Microsoft Academic Search

    Marilia M. Horn; Virginia C. Amaro Martins; Ana Maria de Guzzi Plepis

    2009-01-01

    This work describes the freeze-drying technique preparation and characterization of porous scaffolds (sponges) of blends between chitosan and anionic collagen. Chitosan (CHI) was obtained from the partial deacetylation of squid pen chitin and the anionic collagen was prepared by alkaline hydrolysis of porcine serosa at different times (COL24, COL48, COL72 and COL96h). Separate materials and sponges (1:1) were characterized by

  18. Collagen–chitosan polymeric scaffolds for the in vitro culture of human epidermoid carcinoma cells

    Microsoft Academic Search

    N Shanmugasundaram; P Ravichandran; P Neelakanta Reddy; Nalini Ramamurty; Subrata Pal; K Panduranga Rao

    2001-01-01

    A biodegradable polymer scaffold was developed using collagen and chitosan, in the form of interpenetrating polymeric network (IPN), for in vitro culture of human epidermoid carcinoma cells (HEp-2, Cincinnati). Glutaraldehyde was used as cross-linking agent for the development of scaffold. Various types of scaffolds were prepared using different proportionate mixtures of collagen and chitosan solutions in the ratio of 3:7,

  19. Transcriptional Response of Saccharomyces cerevisiae to the Plasma Membrane-Perturbing Compound Chitosan

    PubMed Central

    Zakrzewska, Anna; Boorsma, Andre; Brul, Stanley; Hellingwerf, Klaas J.; Klis, Frans M.

    2005-01-01

    Chitosan is a plasma membrane-perturbing compound consisting of linear chains of ?-1,4-linked glucosamine residues, which at acidic pHs become positively charged. It is extensively used as an antimicrobial compound, yet its mode of action is still unresolved. Chitosan strongly affected the growth of the yeast Saccharomyces cerevisiae, the food spoilage yeast Zygosaccharomyces bailii, and two human-pathogenic yeasts, Candida albicans and Candida glabrata. Microarray analysis of yeast cells treated with sublethal concentrations of chitosan revealed induction of the environmental stress response and three more major transcriptional responses. The first was a rapid and stable Cin5p-mediated response. Cin5p/Yap4p is a transcription factor involved in various stress responses. Deletion of CIN5 led to increased chitosan sensitivity. The second was a Crz1p-mediated response, which is delayed compared to the Cin5p response. Crz1p is a transcription factor of the calcineurin pathway. Cells deleted for CRZ1 or treated with the calcineurin inhibitor FK506 became hypersensitive to chitosan, supporting the notion that the Crz1p-controlled response offers protection against chitosan. The third was a strong Rlm1p-mediated response which ran parallel in time with the Crz1p-regulated response. Rlm1p is a transcription factor of the cell wall integrity pathway, which is activated by cell wall stress. Importantly, chitosan-treated cells became more resistant to ?-1,3-glucanase, which is a well-known response to cell wall stress. We propose that the transcriptional response to chitosan may be representative of other plasma membrane-perturbing compounds. PMID:15821130

  20. Chitosan Hydrogel Containing Capsaicinoids-Loaded Nanocapsules: An Innovative Formulation for Topical Delivery

    Microsoft Academic Search

    Renata V. Contri; Tatiele Katzer; Adriana R. Pohlmann; Silvia S. Guterres

    2010-01-01

    The aim of the present work was to develop and characterize a chitosan hydrogel containing capsaicinoids-loaded nanocapsules intended for topical delivery. Such system is promising since it brings together the skin bioadhesion and film forming capability of chitosan and the control of the drug release due to the reservoir property of the nanocapsules. The hydrogels showed pH values between 4.2