Novel biocomposite of carboxymethyl chitosan and pineapple peel carboxymethylcellulose as sunscreen carrier.

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Wongkom, Lucksanee; Jimtaisong, Ampa

2017-02-01

This study aims to prepare of biocomposite of carboxymethyl chitosan (CM-chitosan) and carboxymethylcellulose (CMC) from Ananas comosus (pineapple) peel for use as broad spectrum sunscreen carrier. Biocomposite was produced by using ferulic acid (FA), a plant extract, as crosslinker with the optimal ratio of CMC: CM-chitosan: FA at 1:2:4%w. FT-IR technique demonstrated that crosslinking may occur at amine group of CM-chitosan and carboxyl group of FA and hydrogen bonding between hydroxyl group of CMC and carboxyl group of FA. Biocomposite is pale yellow powder and present fibre bundle-like surface in the SEM image. DSC, TGA and XRD results indicated that new compound was formed. The particle size of biocomposite is 626nm determined by using Zetasizer. Hydrophilic TiO 2 and phenylbenzimidazole sulphonic acid (PBSA) were used as sunscreen agent at ratio of TiO 2 : PBSA at 2:1%w. The biocomposite sunscreen possesses the SPF value of 2.47 with boost star rating of 3 at 2% compound. The results obtained indicate that the biocomposite was successfully prepared from CM-chitosan and pineapple peel CMC and the system can be used as matrix delivery system for hydrophilic sunscreens. Copyright © 2016 Elsevier B.V. All rights reserved.

Chitosan and carboxymethyl-chitosan capping ligands: Effects on the nucleation and growth of hydroxyapatite nanoparticles for producing biocomposite membranes

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Dumont, Vitor C.; Mansur, Alexandra A.P.; Carvalho, Sandhra M.; Medeiros Borsagli, Fernanda G.L.; Pereira, Marivalda M.; Mansur, Herman S., E-mail: hmansur@demet.ufmg.br

2016-02-01

Synthetic biomaterials based on calcium phosphates (CaP) have been widely studied for bone tissue reconstruction therapies, but no definitive solution that fulfills all of the required properties has been identified. Thus, this study reports the synthesis of composite membranes based on nanohydroxyapatite particles (nHA) embedded in chitosan (CHI) and O-carboxymethyl chitosan (CMC) matrices produced using a one-step co-precipitation method in water media. Biopolymers were used as capping ligands for simultaneously controlling the nucleation and growth of the nHA particles during the precipitation process and also to form the polymeric network of the biocomposites. The bionanocomposites were extensively characterized using light microscopy (LM), scanning and transmission electron microscopy (SEM/TEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), atomic force microscopy (AFM), X-ray micro-CT analysis (μCT), and MTT (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) cell proliferation assays for cell cytotoxicity. The results demonstrated that the ligands used during the synthesis highly affected the composites produced, primarily due the changes in the mechanisms and kinetics of nucleation and growth of the HA particles at the nanoscale level. The SEM images revealed that the use of carboxyl-functionalized chitosan (CMC) ligands significantly reduced the average size of the HA nanoparticles and caused the formation of a narrower size distribution (90 ± 20 nm) compared to the HA nanoparticles produced with chitosan ligands (220 ± 50 nm). The same trend was verified by the AFM analysis, where the nHA particles were formed evenly dispersed in the polymer matrix. However, the CMC-based composites were more homogeneously distributed, which was endorsed by the images collected via X-ray micro-CT. The FTIR spectra and the XRD analysis indicated that nanosized hydroxyapatite was the

Evaluation of carboxymethyl moringa gum as nanometric carrier.

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Rimpy; Abhishek; Ahuja, Munish

2017-10-15

In the present study, carboxymethylation of Moringa oleifera gum was carried out by reacting with monochloroacetic acid. Modified gum was characterised employing Fourier-transform infrared spectroscopy, differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, and Rheology study. The carboxymethyl modification of moringa gum was found to increase its degree of crystallinity, reduce viscosity and swelling, increase the surface roughness and render its more anionic. The interaction between carboxymethyl moringa gum and chitosan was optimised by 2-factor, 3-level central composite experimental design to prepare polyelectrolyte nanoparticle using ofloxacin, as a model drug. The optimal calculated parameters were found to be carboxymethyl moringa gum- 0.016% (w/v), chitosan- 0.012% (w/v) which provided polyelectrolyte nanoparticle of average particle size 231nm and zeta potential 28mV. Carboxymethyl moringa gum-chitosan polyelectrolyte nanoparticles show sustained in vitro release of ofloxacin upto 6h which followed first order kinetics with mechanism of release being erosion of polymer matrix. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of dorzolamide loaded 6-o-carboxymethyl chitosan nanoparticles for open angle glaucoma.

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Shinde, Ujwala; Ahmed, Mohammed Hadi; Singh, Kavita

2013-01-01

Chitosan (CS) is a biodegradable, biocompatible, and mucoadhesive natural polymer soluble in acidic pH only and can be irritating to the eye. Objective of the study was to synthesize water soluble 6-O-carboxymethyl (OCM-CS) derivative of CS, and to develop CS and OCM-CS nanoparticles (NPs) loaded with dorzolamide hydrochloride (DRZ). CS was reacted with monochloroacetic acid (MCA) for OCM-CS synthesis and was characterized by FT-IR, DSC, and (13)C NMR. CS and OCM-CS NPs were prepared by ionic gelation method. Ocular irritation potential were evaluated and therapeutic efficacy was measured by reduction in intraocular pressure (IOP) in normotensive rabbits. Maximum yield was obtained when the ratio of water/isopropyl alcohol was 1/4 at 55°C. The FT-IR, DSC and (13)C NMR confirmed the formation of an ether linkage between hydroxyl groups of CS and MCA. The particle size and zeta potential of optimised CSNPs was 250.3 ± 2.62 nm and +33.47 ± 0.723 mV, whereas those for OCM-CSNPs were 187.1 ± 2.72 nm and 30.87 ± 0.86 mV. The entrapment efficiency was significantly improved for OCM-CSNPs, compared to CSNPs. OCM-CSNPs had tailored drug release and improved bioavailability with reduction in pulse entry as compared to CSNPs. Hence, it can be concluded that DRZ loaded OCM-CSNPs would be better alternative option to available eye drops for glaucoma treatment.

Synthesis and Characterization of Carboxymethyl Chitosan Nanogels for Swelling Studies and Antimicrobial Activity

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Reem K. Farag

2012-12-01

Full Text Available Nanogels of a binary system of carboxymethyl chitosan (CMCh and poly- (vinyl alcohol PVA, were successfully synthesized by a novel in situ process. They were also characterized by various analytical tools like Fourier transform infrared spectroscopy (FTIR, transmission electron microscopy (TEM and X-ray diffraction (XRD. They were studied for their unique swelling properties in water and different pH solutions. They were also investigated for their great ability to capture or isolate bacteria and fungi from aquatic environments.

Synthesis of carboxymethylated and quaternized chitosans and their therapeutic effect on nonalcoholic Fatty liver disease.

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Liu, Xiaofei; Yang, Fan; Song, Tao; Zeng, Anrong; Wang, Qi; Sun, Zhong; Shen, Jun

2011-10-12

O-Carboxymethyl chitosan (O-CMCs) and N-((2-hydroxy-3-N,N-dimethylhexadecylammonium)propyl)chitosan chloride (N-CQCs) were synthesized for nonalcoholic fatty liver disease (NAFLD) treatment. The weight-average weight and substitution degree of O-CMCs and N-CQCs were 6.5 × 10(4) and 0.72 and 7.9 × 10(4) and 0.21, respectively. O-CMCs was negatively charged with a zeta-potential value of -31.82 mV, whereas that of N-CQCs was +36.1 mV, and both showed low cytotoxcity. Serum lipid level and liver fat accumulation were reduced with chitosan and its two derivatives. Furthermore, mRNA and protein expression assay of hepatic lipid metabolism enzymes and low-density lipoprotein receptor (LDL-R) were observed by RT-PCR and Western blot. Results showed that N-CQCs exhibited a more evident desired effect than chitosan and O-CMCs, indicating that amphiphilicity, solubility, and surface charge of chitosan and its two derivatives played roles in the expression of hepatic lipid metabolism enzymes and LDL-R. Therefore, dietary supplementation of O-CMCs and N-CQCs can alleviate the high fat diet induced aberrations related to NAFLD by their antilipidemic property.

Preparation of N,O-carboxymethyl chitosan coated alginate microcapsules and their application to Bifidobacterium longum BIOMA 5920.

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Mi, Yu; Su, Ran; Fan, Dai-Di; Zhu, Xiao-Li; Zhang, Wen-Ni

2013-07-01

In order to greatly improve vitality of probiotic bacteria within the application, a novel biocompatible vehicle, N,O-carboxymethyl chitosan (NOCs) with appropriate degrees of substitution coat alginate (ALg) microparticles, was prepared by electrostatic droplet generation. The amount of chitosan (Cs) and N,O-carboxymethyl chitosan (NOCs) coated on the ALg microparticles was determined by differential scanning calorimetry. The surface morphology of ALg microparticles, Cs coated ALg microparticles and NOCs coated ALg microparticles was determined using scanning electron microscopy. The coating thickness of Cs coated ALg microparticles and that of NOCs coated ALg microparticles was directly observed with confocal laser scanning microscopy. In order to assess pH sensitivity of microparticles, the bovine serum albumin release from the microspheres was tested in acid solution (pH 2.0) for 2 h and subsequently in alkaline solution (pH 7.0) for 2 h. The survival of Bifidobacterium longum BIOMA 5920 loaded in NOCs coated with ALg microparticle was improved in simulated gastric juice (pH 2.0, for 2 h) compared to that of B. longum BIOMA 5920 loaded in ALg microparticles and Cs coated ALg microparticles. After incubation in simulated intestinal juices (pH 7.0, 2 h), the release of microencapsulated B. longum BIOMA 5920 was investigated. Copyright © 2013 Elsevier B.V. All rights reserved.

Development of Dorzolamide Loaded 6-O-Carboxymethyl Chitosan Nanoparticles for Open Angle Glaucoma

Directory of Open Access Journals (Sweden)

Ujwala Shinde

2013-01-01

Full Text Available Chitosan (CS is a biodegradable, biocompatible, and mucoadhesive natural polymer soluble in acidic pH only and can be irritating to the eye. Objective of the study was to synthesize water soluble 6-O-carboxymethyl (OCM-CS derivative of CS, and to develop CS and OCM-CS nanoparticles (NPs loaded with dorzolamide hydrochloride (DRZ. CS was reacted with monochloroacetic acid (MCA for OCM-CS synthesis and was characterized by FT-IR, DSC, and 13C NMR. CS and OCM-CS NPs were prepared by ionic gelation method. Ocular irritation potential were evaluated and therapeutic efficacy was measured by reduction in intraocular pressure (IOP in normotensive rabbits. Maximum yield was obtained when the ratio of water/isopropyl alcohol was 1/4 at 55°C. The FT-IR, DSC and 13C NMR confirmed the formation of an ether linkage between hydroxyl groups of CS and MCA. The particle size and zeta potential of optimised CSNPs was 250.3 ± 2.62 nm and +33.47 ± 0.723 mV, whereas those for OCM-CSNPs were 187.1 ± 2.72 nm and 30.87 ± 0.86 mV. The entrapment efficiency was significantly improved for OCM-CSNPs, compared to CSNPs. OCM-CSNPs had tailored drug release and improved bioavailability with reduction in pulse entry as compared to CSNPs. Hence, it can be concluded that DRZ loaded OCM-CSNPs would be better alternative option to available eye drops for glaucoma treatment.

Trimethyl and carboxymethyl chitosan carriers for bio-active polymer-inorganic nanocomposites.

Science.gov (United States)

Geisberger, Georg; Gyenge, Emina Besic; Maake, Caroline; Patzke, Greta R

2013-01-02

The carrier properties of carboxymethyl chitosan (CMC) and trimethyl chitosan (TMC) in combination with polyoxometalates (POMs) as inorganic drug prototypes are compared with respect to the influence of polymer matrix charge and structure on the emerging composites. A direct crosslinking approach with TMC and K(6)H(2)[CoW(11)TiO(40)]·13H(2)O ({CoW(11)TiO(40)}) as a representative anticancer POM affords nanocomposites with a size range of 50-90nm. The obtained POM-chitosan composites are characterized with a wide range of analytical methods, and POM encapsulation into positively charged TMC brings forward different nanocomposite morphologies and properties than CMC as a carrier material. Furthermore, uptake of fluorescein isothiocyanate (FITC) labeled POM-CMC and POM-TMC by HeLa cells was monitored, and the influence of chlorpromazine (CP) as inhibitor of the clathrin mediated pathway revealed different cellular uptake behavior of composites and pristine carriers. TMC/{CoW(11)TiO(40)} nanocomposites are taken up by HeLa cells after short incubation times around 30 min at low concentrations. The anticancer activity of pristine {CoW(11)TiO(40)} and its TMC-nanocomposites was investigated in vitro with MTT assays and compared to a reference POM. Copyright © 2012 Elsevier Ltd. All rights reserved.

Preparation and Pb(II Adsorption Properties of Crosslinked Pectin-Carboxymethyl Chitosan Film

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Budi Hastuti

2015-11-01

Full Text Available A modified pectin has been synthesized by reacting/combining -OH group among pectin and chitosan with BADGE (Bisphenol A diglycidyl ether crosslinker agent. The structure and morphology of the new material were characterized by Fourier transform infrared (FTIR spectroscopy, scanning electron microscopy (SEM and X-ray Diffraction (XRD analysis. Thermogravimetric studies showed an improvement in thermal characteristic. Adsorption experiments were performed in batch processes; sorption isotherms and kinetics were also studied. The Langmuir and Freundlich adsorption isotherm models were applied to describe the isotherms and isotherm constants for the adsorption of Pb(II ion onto adsorbent pectin-carboxymethyl chitosan-BADGE (pec-CMC-BADGE. The dynamic study showed that the sorption process followed the second-order kinetic equation. Result indicated also that Pb(II ion uptake could be well described by the Langmuir and Freundlich adsorption model of pec-CMC-BADGE and CMC with DG° of 25.3 and 23.1 kJ mol-1,respectively, while that of pectin followed Freundlich isotherm with DG° of 16.6 kJ mol-1.

A facile method for electrospinning of Ag nanoparticles/poly (vinyl alcohol)/carboxymethyl-chitosan nanofibers

International Nuclear Information System (INIS)

Zhao, Yinghui; Zhou, Ying; Wu, Xiaomian; Wang, Lu; Xu, Ling; Wei, Shicheng

2012-01-01

Highlights: ► AgNPs/PVA/CM-chitosan nanofibers were prepared via electrospinning method. ► AgNPs were in situ synthesized in electrospinning solution via a facile method. ► AgNPs distributed homogeneously on the surface of nanofibers. ► The prepared nanofibers possessed certain antibacterial ability against Escherichia coli. ► The AgNPs containing nanofibers had potential as antibacterial biomaterial. - Abstract: A facile method to prepare silver nanoparticles (AgNPs) containing nanofibers via electrospinning has been demonstrated. AgNPs were in situ synthesized in poly (vinyl alcohol) (PVA)/carboxymethyl-chitosan (CM-chitosan) blend aqueous solution before electrospinning. UV–vis spectra, viscosity and conductivity of the electrospinning solution were measured to investigate their effects on the electrospinning procedure. The morphology of AgNPs/PVA/CM-chitosan nanofibers was observed by Field Emission Scanning Electron Microscopy. The formation and morphology of AgNPs were investigated by Transmission Electron Microscopy and X-ray Photoelectron Spectroscopy. The resulted nanofibers have smooth surface and uniform diameters ranging from 295 to 343 nm. The diameters of AgNPs mainly distributed in the range of 4–14 nm, and the electrostatic interaction between AgNPs and fibers was observed. Finally, in vitro Ag release from the nanofibers was measured and the antibacterial behavior of the nanofibers against Escherichia coli was studied by bacterial growth inhibition halos and bactericidal kinetic testing. The AgNPs/PVA/CM-chitosan nanofibers possessed certain antibacterial ability, which makes them capable for antibacterial biomaterials.

Conductivity enhancement via chemical modification of chitosan based green polymer electrolyte

International Nuclear Information System (INIS)

Mobarak, N.N.; Ahmad, A.; Abdullah, M.P.; Ramli, N.; Rahman, M.Y.A.

2013-01-01

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

New sizing agents and flocculants derived from chitosan

International Nuclear Information System (INIS)

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

2005-01-01

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

Synthesis and Characterization Pectin-Carboxymethyl Chitosan crosslinked PEGDE as biosorbent of Pb(II) ion

Science.gov (United States)

Hastuti, Budi; Siswanta, Dwi; Mudasir; Triyono

2018-01-01

Pectin and chitosan are biodegradable polymers, potentially applied as a heavy metal adsorbents. Unfortunately both biosorbents pectin and chitosan have a weakness in acidic media. For this purpose required modified pectin and chitosan. The modified adsorben is intended to obtain a stable adsorbent and resistance under acid. The research was done by experimental method in laboratory. The stages of this research are the synthesis of carboxymethyl chitosan (CMC), synthesis of Pec-CMC-PEGDE film adsorbent, stabily test under acid, the characterization of active group using FTIR, stability characterization of Pec-CMC-PEGDE powder adsorbent using XRD, termo stability using DTA-TGA. The results of the research have shown that: pectin and CMC can be cross-linked using PEGDE crosslinking agent, the film adsorbent was stable under HCl 1 M, the film adsorbent have active group comprise of carboxylate and amine groups. The result of characterization using XRD, shows that the adsorbent is semi-crystalline. Base on termo stability, the film adsorbent Pec-CMC-PEGDE stable up to 600°C. The film can be applied as an adsobent of Pb (II) ion remediation. The optimum pH of pec-CMC-PEGDE in adsorbed of Pb(II) was reached at pH 5 with 99.99% absorbent adsorbed and of and adsorption capacity was 46.11 mg/g.

Quaternized Carboxymethyl Chitosan-Based Silver Nanoparticles Hybrid: Microwave-Assisted Synthesis, Characterization and Antibacterial Activity

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Siqi Huang

2016-06-01

Full Text Available A facile, efficient, and eco-friendly approach for the preparation of uniform silver nanoparticles (Ag NPs was developed. The synthesis was conducted in an aqueous medium exposed to microwave irradiation for 8 min, using laboratory-prepared, water-soluble quaternized carboxymethyl chitosan (QCMC as a chemical reducer and stabilizer and silver nitrate as the silver source. The structure of the prepared QCMC was characterized using Fourier transform infrared (FT-IR and 1H nuclear magnetic resonance (NMR. The formation, size distribution, and dispersion of the Ag NPs in the QCMC matrix were determined using X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, ultraviolet-visible (UV-Vis, transmission electron microscopy (TEM, and field emission scanning electron microscope (FESEM analysis, and the thermal stability and antibacterial properties of the synthesized QCMC-based Ag NPs composite (QCMC-Ag were also explored. The results revealed that (1 QCMC was successfully prepared by grafting quaternary ammonium groups onto carboxymethyl chitosan (CMC chains under microwave irradiation in water for 90 min and this substitution appeared to have occurred at -NH2 sites on C2 position of the pyranoid ring; (2 uniform and stable spherical Ag NPs could be synthesized when QCMC was used as the reducing and stabilizing agent; (3 Ag NPs were well dispersed in the QCMC matrix with a narrow size distribiution in the range of 17–31 nm without aggregation; and (4 due to the presence of Ag NPs, the thermal stability and antibacterial activity of QCMC-Ag were dramatically improved relative to QCMC.

Quaternized Carboxymethyl Chitosan-Based Silver Nanoparticles Hybrid: Microwave-Assisted Synthesis, Characterization and Antibacterial Activity.

Science.gov (United States)

Huang, Siqi; Wang, Jing; Zhang, Yang; Yu, Zhiming; Qi, Chusheng

2016-06-17

A facile, efficient, and eco-friendly approach for the preparation of uniform silver nanoparticles (Ag NPs) was developed. The synthesis was conducted in an aqueous medium exposed to microwave irradiation for 8 min, using laboratory-prepared, water-soluble quaternized carboxymethyl chitosan (QCMC) as a chemical reducer and stabilizer and silver nitrate as the silver source. The structure of the prepared QCMC was characterized using Fourier transform infrared (FT-IR) and ¹H nuclear magnetic resonance (NMR). The formation, size distribution, and dispersion of the Ag NPs in the QCMC matrix were determined using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible (UV-Vis), transmission electron microscopy (TEM), and field emission scanning electron microscope (FESEM) analysis, and the thermal stability and antibacterial properties of the synthesized QCMC-based Ag NPs composite (QCMC-Ag) were also explored. The results revealed that (1) QCMC was successfully prepared by grafting quaternary ammonium groups onto carboxymethyl chitosan (CMC) chains under microwave irradiation in water for 90 min and this substitution appeared to have occurred at -NH₂ sites on C2 position of the pyranoid ring; (2) uniform and stable spherical Ag NPs could be synthesized when QCMC was used as the reducing and stabilizing agent; (3) Ag NPs were well dispersed in the QCMC matrix with a narrow size distribiution in the range of 17-31 nm without aggregation; and (4) due to the presence of Ag NPs, the thermal stability and antibacterial activity of QCMC-Ag were dramatically improved relative to QCMC.

A facile method for electrospinning of Ag nanoparticles/poly (vinyl alcohol)/carboxymethyl-chitosan nanofibers

Energy Technology Data Exchange (ETDEWEB)

Zhao, Yinghui; Zhou, Ying [Beijing Key Laboratory for Solid Waste Utilization and Management, College of Engineering, Peking University, Beijing 100871 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Wu, Xiaomian [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Department of Orthodontics College of Stomatology, Chongqing Medical University, Chongqing 401147 (China); Wang, Lu [Beijing Key Laboratory for Solid Waste Utilization and Management, College of Engineering, Peking University, Beijing 100871 (China); Xu, Ling, E-mail: lingxu@pku.edu.cn [Beijing Key Laboratory for Solid Waste Utilization and Management, College of Engineering, Peking University, Beijing 100871 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); PKU-HKUST ShenZhen-HongKong Institution, Shenzhen 518057 (China); Wei, Shicheng, E-mail: sc-wei@pku.edu.cn [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Peking University, Beijing 100081 (China)

2012-09-01

Highlights: Black-Right-Pointing-Pointer AgNPs/PVA/CM-chitosan nanofibers were prepared via electrospinning method. Black-Right-Pointing-Pointer AgNPs were in situ synthesized in electrospinning solution via a facile method. Black-Right-Pointing-Pointer AgNPs distributed homogeneously on the surface of nanofibers. Black-Right-Pointing-Pointer The prepared nanofibers possessed certain antibacterial ability against Escherichia coli. Black-Right-Pointing-Pointer The AgNPs containing nanofibers had potential as antibacterial biomaterial. - Abstract: A facile method to prepare silver nanoparticles (AgNPs) containing nanofibers via electrospinning has been demonstrated. AgNPs were in situ synthesized in poly (vinyl alcohol) (PVA)/carboxymethyl-chitosan (CM-chitosan) blend aqueous solution before electrospinning. UV-vis spectra, viscosity and conductivity of the electrospinning solution were measured to investigate their effects on the electrospinning procedure. The morphology of AgNPs/PVA/CM-chitosan nanofibers was observed by Field Emission Scanning Electron Microscopy. The formation and morphology of AgNPs were investigated by Transmission Electron Microscopy and X-ray Photoelectron Spectroscopy. The resulted nanofibers have smooth surface and uniform diameters ranging from 295 to 343 nm. The diameters of AgNPs mainly distributed in the range of 4-14 nm, and the electrostatic interaction between AgNPs and fibers was observed. Finally, in vitro Ag release from the nanofibers was measured and the antibacterial behavior of the nanofibers against Escherichia coli was studied by bacterial growth inhibition halos and bactericidal kinetic testing. The AgNPs/PVA/CM-chitosan nanofibers possessed certain antibacterial ability, which makes them capable for antibacterial biomaterials.

Nano-hybrid carboxymethyl-hexanoyl chitosan modified with (3-aminopropyl)triethoxysilane for camptothecin delivery.

Science.gov (United States)

Hsiao, Meng-Hsuan; Tung, Tsan-Hua; Hsiao, Chi-Sheng; Liu, Dean-Mo

2012-06-20

Silane-modified amphiphilic chitosan was synthesized by anchoring a silane coupling agent, (3-aminopropyl)triethoxysilane, to a novel amphiphilic carboxymethyl-hexanoyl chitosan (CHC). The chemical structure of this new organic-inorganic hybrid molecule was characterized by FTIR and 13C-, 29Si-nuclear magnetic resonance, while the structural evolution was examined using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and dynamic light scattering (DLS). Experimental results indicated a self-assembly behaviour of molecules into nanoparticles with a stable polygonal geometry, consisting of ordered silane layers of 6 nm in thickness. The self-assembly property was found to be influenced by chemical composition and concentration of silane incorporated, while the size can be varied by the amount of anchored silane. It was also demonstrated that such vesicle exhibited excellent cytocompatibility and cellular internalization capability in ARPE-19 cell line, and presented well-controlled encapsulation and release profiles for (S)-(+)-camptothecin. These unique properties render it as a potential drug delivery nanosystem. Copyright © 2012 Elsevier Ltd. All rights reserved.

Transport mechanism of chitosan-N-acetylcysteine, chitosan oligosaccharides or carboxymethyl chitosan decorated coumarin-6 loaded nanostructured lipid carriers across the rabbit ocular.

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Li, Jinyu; Tan, Guoxin; Cheng, Bingchao; Liu, Dandan; Pan, Weisan

2017-11-01

To facilitate the hydrophobic drugs modeled by coumarin-6 (Cou-6) acrossing the cornea to the anterior chamber of the rabbit eye, chitosan (CS) derivatives including chitosan-N-acetyl-l-cysteine (CS-NAC), chitosan oligosaccharides (COS) and carboxymethyl chitosan (CMCS) modified nanostructured lipid carriers (NLCs) were designed and characterized. We found that, with similar size distribution and positivecharges, different CS derivatives based on NLCs led to distinctive delivery performance. In vivo precorneal retention study on rabbits revealed that these CS derivatives coating exhibited a stronger resistant effect than Cou-6 eye drops and Cou-6-NLC (P<0.05), moreover, the AUC (0-∞) , C max and MRT (0-∞) of them followed the sequence of CMCS-Cou-6-NLC

Antibacterial cotton fabric with enhanced durability prepared using silver nanoparticles and carboxymethyl chitosan.

Science.gov (United States)

Xu, QingBo; Xie, LiJing; Diao, Helena; Li, Fang; Zhang, YanYan; Fu, FeiYa; Liu, XiangDong

2017-12-01

Carboxymethyl chitosan (CMCTS) and silver nanoparticles (Ag NPs) were successfully linked onto a cotton fabric surface through a simple mist modification process. The CMCTS binder was covalently linked to the cotton fabric via esterification and the Ag NPs were tightly adhered to the fiber surface by coordination bonds with the amine groups of CMCTS. As a result, the coating of Ag NPs on the cotton fabric showed excellent antibacterial properties and laundering durability. After 50 consecutive laundering cycles, the bacterial reduction rates (BR) against both S. aureus and E. coli remained over 95%. It has potential applications in a wide variety of fields such as sportswear, socks, and medical textile. Copyright © 2017 Elsevier Ltd. All rights reserved.

Preparation of gold/carboxymethyl chitosan nanoparticles by radiation technique for application as an antioxidant

International Nuclear Information System (INIS)

Le Quang Luan; Nguyen Thanh Long; Nguyen Hai Nam; Do Thi Phuong Linh

2015-01-01

Gold nanoparticles (AuNPs) with the sizes of 5.2, 6.7 and 7.3 nm have been synthesised by γ-irradiation of Au 3+ solutions with the corresponding concentrations of 0.25, 0.5 and 1.0 mM using carboxylmethyl chitosan as stabiliser. The optical characteristics and particle sizes of AuNPs have been determined by UV-Vis spectra and TEM images respectively. The antioxidant activity of AuNPs has been investigated at the concentrations of 0.025 mM and 0.5 mM using ABTS scavenging activity. The results have shown that the higher concentration of AuNPs displays the stronger antioxidant activity and the faster reaction time. The highest antioxidant activity has been found at the concentration of 0.375 mM within 2-3 minutes. The antioxidant activity of AuNPs increases by the increase of reaction time and is higher than that of ascorbic acid. Thus, gold/carboxymethyl chitosan nanoparticles prepared by γ-irradiation method can be potentially utilised for the production of antioxidant products in pharmaceutics, functional foods and cosmetics. (author)

Silver deposited carboxymethyl chitosan-grafted magnetic nanoparticles as dual action deliverable antimicrobial materials.

Science.gov (United States)

Vo, Duc-Thang; Sabrina, Sabrina; Lee, Cheng-Kang

2017-04-01

Carboxymethyl chitosan (CMCS) was known to have a much better antimicrobial activity than chitosan due to the increased cationic -NH 3 + groups resulted from the intra- and intermolecular interactions between the carboxyl and amino groups. CMCS was grafted onto the surface of silica coated magnetic nanoparticles (MNPs) to obtain magnetically retrievable and deliverable antimicrobial nanoparticles (MNPs@CMCS). The presence of carboxylate groups in CMCS not only enhanced antimicrobial activity but also enabled Ag ions chelating ability to induce the in situ formation of Ag nanoparticles (AgNPs). The deposition of AgNPs on the surface of MNPs@CMCS could significantly increase its antimicrobial activity against planktonic cells due to the dual action of CMCS and AgNPs. Due to its high magnetism, the as-prepared MNPs@CMCS-Ag could be efficiently delivered into an existing biofilm under the guidance of an applied magnetic field. Without direct contact, the Ag ions and/or radical oxygen species (ROS) released from the deposited Ag nanoparticles could effectively kill the bacteria embedded in the extracellular polymeric substances (EPS) matrix of biofilm. Copyright © 2016 Elsevier B.V. All rights reserved.

Radiation processing of chitosan derivative and its characteristics

International Nuclear Information System (INIS)

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

2002-01-01

Chitosan is natural polymer derived from chitin, a polysaccharide found in the exoskeleton of shrimps, crabs, fungi and others. Chitosan is a naturally occurring substance that is chemically similar to cellulose. Chitosan possesses a positive ionic charge give ability to chemically bond with negatively charged fats. Chitosan is soluble in organic acid but insoluble in water. Carboxymethyl-chitosan (cm-chitosan) is a derivative of chitosan which is water-soluble was then prepared by a carboxymethylation process of chitosan produced from local shrimp shell. A simple method for synthesis of cm-chitosan has been developed at 55 degree C in aqueous sodium hydroxide / propanol with chloroacetic acid (CAA) or sodium chloroacetate salt (SCA). The modification of chitosan to water-soluble chitosan can be used in hydrogel as anti-bacterial agent and it overcome the problem of bad smell using acetic acid. (Author)

Physicochemical properties and drug release behavior of biguanidino and O-carboxymethyl chitosan microcapsules.

Science.gov (United States)

Huo, Weiqiang; Zhang, Weixin; Wang, Wei; Zhou, Xiaohua

2014-09-01

Two types of microcapsules (MCs) were prepared by the emulsion cross-linking method, where biguanidino chitosan (BGCS)and O-carboxymethyl chitosan (O-CMCS) served as the wall materials, and the antibacterial agent 2,4-diamino-6-(2-pyridyl)-1,3,5-triazine (PyTNH) served as a model water-soluble drug. The physicochemical performance of the MCs and their drug release behavior were investigated by Fourier transform infrared spectroscopy, thermogravimetric analysis/derivative thermogravimetric analysis, scanning electron microscopy, and swelling and in vitro drug release studies of the two MCs with unmodified chitosan-MCs (CS-MCs) used as the control. The results indicated that the degree of cross-linking, encapsulation efficiency, and thermal stability of the shell wall of the BGCS-microcapsules (BGCS-MCs) were much higher than those of the control and the O-CMCS-microcapsules (CMCS-MCs), owing to the reduction of steric hindrance and development of the conjugation effect in the cross-linking process. Studies on the swelling and in vitro drug-release behavior revealed a sustained release effect of the BGCS-MCs. Moreover, the CMCS-MCs were found to exhibit a pH-dependent drug release behavior, which can be attributed to the successive formation of H-bonds and repulsive forces with the change in the pH of the medium. Based on these results, the swelling-release models and the drug release kinetics of BGCS-MCs and CMCS-MCs are proposed. Copyright © 2014 Elsevier B.V. All rights reserved.

In situ green synthesis of antimicrobial carboxymethyl chitosan-nanosilver hybrids with controlled silver release.

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Huang, Siqi; Yu, Zhiming; Zhang, Yang; Qi, Chusheng; Zhang, Shifeng

2017-01-01

In order to fabricate antimicrobial carboxymethyl chitosan-nanosilver (CMC-Ag) hybrids with controlled silver release, this study demonstrated comparable formation via three synthetic protocols: 1) carboxymethyl chitosan (CMC) and glucose (adding glucose after AgNO 3 ), 2) CMC and glucose (adding glucose before AgNO 3 ), and 3) CMC only. Under principles of green chemistry, the synthesis was conducted in an aqueous medium exposed to microwave irradiation for 10 minutes with nontoxic chemicals. The structure and formation mechanisms of the three CMC-Ag hybrids were explored using X-ray diffraction, ultraviolet-visible spectroscopy, transmission electron microscopy, and Fourier-transform infrared analyses. Additionally, antimicrobial activity and in vitro silver release of the three synthesized hybrids were investigated in detail. The results revealed that a large number of stable, uniform, and small silver nanoparticles (AgNPs) were synthesized in situ on CMC chains via protocol 1. AgNPs were well dispersed with narrow size distribution in the range of 6-20 nm, with mean diameter only 12.22±2.57 nm. The addition of glucose resulted in greater AgNP synthesis. The order of addition of glucose and AgNO 3 significantly affected particle size and size distribution of AgNPs. Compared to CMC alone and commercially available AgNPs, the antimicrobial activities of three hybrids were significantly improved. Of the three hybrids, CMC-Ag1 synthesized via protocol 1 exhibited better antimicrobial activity than CMC-Ag2 and CMC-Ag3, and showed more effective inhibition of Staphylococcus aureus than Escherichia coli . Due to strong coordination and electrostatic interactions between CMC and silver and good steric protection provided by CMC, CMC-Ag1 displayed stable and continuous silver release and better performance in retaining silver for prolonged periods than CMC-Ag2 and CMC-Ag3.

miRNA-218-loaded carboxymethyl chitosan - Tocopherol nanoparticle to suppress the proliferation of gastrointestinal stromal tumor growth

Energy Technology Data Exchange (ETDEWEB)

Tu, Lin; Wang, Ming; Zhao, Wen-Yi; Zhang, Zi-Zhen; Tang, De-Feng; Zhang, Ye-Qian [Department of Gastrointestinal Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127 (China); Cao, Hui, E-mail: caohui10281@163.com [Department of Gastrointestinal Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127 (China); Zhang, Zhi-Gang, E-mail: zhangzhiganggz@hotmail.com [State Key Laboratory for Oncogenes and Related Genes, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200240 (China)

2017-03-01

Gastrointestinal stromal tumors (GIST) are one of the most common forms of mesenchymal cancers of the gastrointestinal tract. Although chemotherapeutic drugs inhibited the proliferation of GIST, however, sizable proportion of people developed resistance and therefore difficult to treat. In the present study, O-carboxymethyl chitosan (OCMC)-tocopherol polymer conjugate was synthesized and formulated into stable polymeric nanoparticles. The main aim of present study was to increase the therapeutic efficacy of miR-218 in GIST. The mean size of nanoparticles was ~ 110 nm with a spherical shape. The miR-218 NP has been shown inhibit the cell proliferation and exhibited a superior cell apoptosis. The miR-218 NP inhibited the cell invasion and promoted the apoptosis of GIST cancer cells. In the present study, we have successfully showed that KIT1 is the target gene of miR-218 as shown by the luciferase reporter assay. These findings collectively suggest the miR-218 loaded nanoparticle by virtue of effective transfection could act as a tumor suppressor miRNA in the treatment of GIST. - Highlights: • O-carboxymethyl chitosan (OCMC)-tocopherol polymer conjugate was synthesized and formulated in nanoparticles. • The miR-218 NP has been shown inhibit the cell proliferation and exhibited a superior cell apoptosis. • We have successfully showed that KIT1 is the target gene of miR-218 as shown by the luciferase reporter assay.

Development of an injectable chitosan/marine collagen composite gel

International Nuclear Information System (INIS)

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

2010-01-01

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

Implantable biodegradable sponges: effect of interpolymer complex formation of chitosan with gelatin on the release behavior of tramadol hydrochloride.

Science.gov (United States)

Foda, Nagwa H; El-laithy, Hanan M; Tadros, Mina I

2007-01-01

The effect of interpolymer complex formation between positively charged chitosan and negatively charged gelatin (Type B) on the release behavior of tramadol hydrochloride from biodegradable chitosan-gelatin sponges was studied. Mixed sponges were prepared by freeze-drying the cross-linked homogenous stable foams produced from chitosan and gelatin solutions where gelatin acts as a foam builder. Generation of stable foams was optimized where concentration, pH of gelatin solution, temperature, speed and duration of whipping process, and, chitosan-gelatin ratio drastically affect the properties and the stability of the produced foams. The prepared sponges were evaluated for their morphology, drug content, and microstructure using scanning electron microscopy, mechanical properties, uptake capacity, drug release profile, and their pharmacodynamic activity in terms of the analgesic effect after implantation in Wistar rats. It was revealed that whipping 7% (w/w) gelatin solution, of pH 5.5, for 15 min at 25 degrees C with a stirring speed of 1000 rpm was the optimum conditions for stable gelatin foam generation. Moreover, homogenous, uniform chitosan-gelatin foam with small air bubbles were produced by mixing 2.5% w/w chitosan solution with 7% w/w gelatin solution in 1:5 ratio. Indeed, polyionic complexation between chitosan and gelatin overcame the drawbacks of chitosan sponge mechanical properties where, pliable, soft, and compressible sponge with high fluid uptake capacity was produced at 25 degrees C and 65% relative humidity without any added plasticizer. Drug release studies showed a successful retardation of the incorporated drug where the t50% values of the dissolution profiles were 0.55, 3.03, and 4.73 hr for cross-linked gelatin, un-cross-linked chitosan-gelatin, and cross-linked chitosan-gelatin sponges, respectively. All the release experiments followed Higuchi's diffusion mechanism over 12 hr. The achieved drug prolongation was a result of a combined effect

Lyophilized sustained release mucoadhesive chitosan sponges for buccal buspirone hydrochloride delivery: formulation and in vitro evaluation.

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Kassem, Mohamed A A; ElMeshad, Aliaa N; Fares, Ahmed R

2015-06-01

This work aims to prepare sustained release buccal mucoadhesive lyophilized chitosan sponges of buspirone hydrochloride (BH) to improve its systemic bioavailability. Chitosan sponges were prepared using simple casting/freeze-drying technique according to 3(2) factorial design where chitosan grade was set at three levels (low, medium, and high molecular weight), and concentration of chitosan solution at three levels (0.5, 1, and 2%). Mucoadhesion force, ex vivo mucoadhesion time, percent BH released after 8 h (Q8h), and time for release of 50% BH (T50%) were chosen as dependent variables. Additional BH cup and core buccal chitosan sponge were prepared to achieve uni-directional BH release toward the buccal mucosa. Sponges were evaluated in terms of drug content, surface pH, scanning electron microscopy, swelling index, mucoadhesion strength, ex vivo mucoadhesion time, and in vitro drug release. Cup and core sponge (HCH 0.5E) were able to adhere to the buccal mucosa for 8 h. It showed Q8h of 68.89% and exhibited a uni-directional drug release profile following Higuchi diffusion model.

Modification of Carboxymethyl Chitosan Film by Blending with Poly(benzyl L-glutamate)-block-poly(ethylene glycol) Copolymer

International Nuclear Information System (INIS)

Zhu, G.Z.; Gao, Q.C.; Liu, Y.Y.

2013-01-01

A series of water-soluble carboxymethyl chitosan (CMCS)/poly(benzyl L-glutamate)-block-poly(ethylene glycol) (PBLG-b-PEG) blend films with various CMCS/PBLG-b-PEG mol ratios were prepared by pervaporation method. Morphologies of CMCS/PBLG-b-PEG blend films were researched by scanning electron microscopy (SEM). Thermal, mechanical, and chemical properties of CMCS/PBLG-b-PEG blend films were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), tensile tests, and contact angle tests. It was revealed that the introduction of PBLG-b-PEG segments could greatly affect the morphology and the properties of CMCS films. (author)

Chitosan and carboxymethyl-chitosan capping ligands: Effects on the nucleation and growth of hydroxyapatite nanoparticles for producing biocomposite membranes.

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Dumont, Vitor C; Mansur, Alexandra A P; Carvalho, Sandhra M; Medeiros Borsagli, Fernanda G L; Pereira, Marivalda M; Mansur, Herman S

2016-02-01

Synthetic biomaterials based on calcium phosphates (CaP) have been widely studied for bone tissue reconstruction therapies, but no definitive solution that fulfills all of the required properties has been identified. Thus, this study reports the synthesis of composite membranes based on nanohydroxyapatite particles (nHA) embedded in chitosan (CHI) and O-carboxymethyl chitosan (CMC) matrices produced using a one-step co-precipitation method in water media. Biopolymers were used as capping ligands for simultaneously controlling the nucleation and growth of the nHA particles during the precipitation process and also to form the polymeric network of the biocomposites. The bionanocomposites were extensively characterized using light microscopy (LM), scanning and transmission electron microscopy (SEM/TEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), atomic force microscopy (AFM), X-ray micro-CT analysis (μCT), andMTT (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazoliumbromide) cell proliferation assays for cell cytotoxicity. The results demonstrated that the ligands used during the synthesis highly affected the composites produced, primarily due the changes in the mechanisms and kinetics of nucleation and growth of the HA particles at the nanoscale level. The SEMimages revealed that the use of carboxyl-functionalized chitosan (CMC) ligands significantly reduced the average size of theHA nanoparticles and caused the formation of a narrower size distribution (90±20nm) compared to theHAnanoparticles producedwith chitosan ligands (220±50nm). The same trend was verified by the AFM analysis,where the nHA particles were formed evenly dispersed in the polymer matrix. However, the CMC-based composites were more homogeneously distributed, which was endorsed by the images collected via X-ray micro-CT. The FTIR spectra and the XRD analysis indicated that nanosized hydroxyapatite was the predominant calcium

Radiation-induced degradation of carboxymethylated chitosan and its application in preparation of ionic liquids and silver nanoparticles

International Nuclear Information System (INIS)

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

2006-01-01

Radiation effect of γ-ray on carboxymethylated chitosan (CM-chitosan) in solid state and aqueous solution were studied. The changes in molecular weight of CM-chitosan with absorbed dose were monitored by viscosity method. In solid state, there are random chain scissions in the radiation process of CM-chitosan. XRD patterns identified that the degradation of CM-chitosan occurred mostly in amorphous region. Radiation chemical yield (G d ) of CM-chitosan in solid state in N 2 atmosphere was 0.49, which showed CM-chitosan has high radiation stability. Biomaterials composed of CM-chitosan can be thought to sterilize with low absorbed doses. While aqueous solutions of CM-chitosan were irradiated with γ-rays in various conditions, degradations of CM-chitosan were faster in the presence of nitrous oxide or hydrogen peroxide, however, it was inhibited obviously by adding isopropanol because of concentration changes of hydroxyl radicals in different conditions. This indicated that hydroxyl radicals play an important role in radiation degradation of CM-chitosan. Furthermore, FTIR and UV spectra of CM-chitosan radiation-degraded in its solid state status or in aqueous solution showed that main chain structures of CM-chitosan were kept and some carbonyl/carboxyl groups formed during the irradiation were similar to radiation degradation products of chitosan. The method can be used to prepare low molecular weight CM-chitosan. Due to special physical and chemical properties, ionic liquids have attracted much attention in green chemistry field. Environment-friendly ionic liquids ([emim]CM-chitosan) were prepared in acid-base neutralization reactions based on 1-ethyl-3-methylimidazolium hydroxide and CM-chitosan with molecular weights ranging from 2000 to 600 Da. Results of thermal analysis showed that molecular weight of CM-chitosan have little influence on glass transition temperature, melting point and decomposing temperature of [emim]CM-chitosan ionic liquids. Conductivities

Carboxymethyl chitosan based nanocomposites containing chemically bonded quantum dots and magnetic nanoparticles

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Ding, Yongling; Yin, Hong; Chen, Rui; Bai, Ru; Chen, Chunying; Hao, Xiaojuan; Shen, Shirley; Sun, Kangning; Liu, Futian

2018-03-01

A biocompatible nanocomposite consisting of fluorescent quantum dots (QDs) and magnetic nanoparticles (MNPs) has been constructed via carboxymethyl chitosan (CMCS), resulting in magnetic-fluorescent nanoparticles (MFNPs). In these MFNPs, QDs and MNPs are successfully conjugated via covalent bonds onto the surface of CMCS. The composite retains favorable magnetic and fluorescent properties and shows a good colloidal stability in physiological environments. Folate (FA) as a specific targeting ligand was further incorporated into the nanocomposites to form a delivery vehicle with a targeting function. The therapeutic activity was achieved by loading chemotherapeutic drug doxorubicin (DOX) through electrostatic and hydrophobic interactions. The cumulative DOX release profile shows pH-sensitive. Both flow cytometry analysis and confocal laser scanning microscopic observation suggested that these nanocomposites were uptaken by cancer cells via FA receptor-mediated endocytosis pathway. In summary, the CMCS based nanocomposites developed in this work have a great potential for effective cancer-targeting and drug delivery, as well as in situ cellular imaging.

High-amylose sodium carboxymethyl starch matrices: development and characterization of tramadol hydrochloride sustained-release tablets for oral administration.

Science.gov (United States)

Nabais, Teresa; Leclair, Grégoire

2014-01-01

Substituted amylose (SA) polymers were produced from high-amylose corn starch by etherification of its hydroxyl groups with chloroacetate. Amorphous high-amylose sodium carboxymethyl starch (HASCA), the resulting SA polymer, was spray-dried to obtain an excipient (SD HASCA) with optimal binding and sustained-release (SR) properties. Tablets containing different percentages of SD HASCA and tramadol hydrochloride were produced by direct compression and evaluated for dissolution. Once-daily and twice-daily SD HASCA tablets containing two common dosages of tramadol hydrochloride (100 mg and 200 mg), a freely water-soluble drug, were successfully developed. These SR formulations presented high crushing forces, which facilitate further tablet processing and handling. When exposed to both a pH gradient simulating the pH variations through the gastrointestinal tract and a 40% ethanol medium, a very rigid gel formed progressively at the surface of the tablets providing controlled drug-release properties. These properties indicated that SD HASCA was a promising and robust excipient for oral, sustained drug-release, which may possibly minimize the likelihood of dose dumping and consequent adverse effects, even in the case of coadministration with alcohol.

Chitosan/o-carboxymethyl chitosan nanoparticles for efficient and safe oral anticancer drug delivery: in vitro and in vivo evaluation.

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Feng, Chao; Wang, Zhiguo; Jiang, Changqing; Kong, Ming; Zhou, Xuan; Li, Yang; Cheng, Xiaojie; Chen, Xiguang

2013-11-30

The present study investigated the ability of a polyelectrolyte complex (CS/CMCS-NPs), composed of chitosan (CS) and o-carboxymeymethy chitosan (CMCS) as a pH responsive carrier for oral delivery of doxorubicin hydrochloride (DOX). The obtained CS/CMCS-NPs were characterized for various parameters including morphology, particle size, zeta potential, entrapment efficiency and stability under the simulated GI tract conditions. The pH responsive stability of the DOX-loaded CS/CMCS nanoparticles (DOX:CS/CMCS-NPs) determined the drug release rate, which was lower in acidic pH than the neutral. Ex vivo intestinal adhesion and permeation indicated DOX:CS/CMCS-NGs were able to enhance absorption of DOX throughout the entire small intestine, especially in jejunum and ileum. Oral administration of DOX:CS/CMCS-NPs was effective to deliver DOX into blood, giving an absolute bioavailability of 42%. The tissue distribution and toxicity of DOX:CS/CMCS-NPs in rats showed low level of DOX in heart and kidney, and obviously decreased cardiac and renal toxicities. These results indicated CS/CMCS-NPs were highly efficient and safe as an oral delivery system for DOX. Copyright © 2013 Elsevier B.V. All rights reserved.

Amphiphilic chitosan derivatives as carrier agents for rotenone

Science.gov (United States)

Kamari, Azlan; Aljafree, Nurul Farhana Ahmad

2017-08-01

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

Synthesis of Pb(II Imprinted Carboxymethyl Chitosan and the Application as Sorbent for Pb(II Ion

Directory of Open Access Journals (Sweden)

Abu Masykur

2014-07-01

Full Text Available The aims of this research is to synthesize Pb(II imprinted polymers with carboxymethyl chitosan (CMC as polymers and bisphenol A diglycidyl ether (BADGE as cross-linker (Pb-IIP. Chitosan (CTS, non imprinted polymer (NIP and Pb-IIP were characterized using infrared (IR spectroscopy, X-ray diffraction (XRD, surface area analyzer (SAA, scanning electron microscopy (SEM, and energy dispersive X-ray (EDX spectroscopy. The result showed that the adsorption was optimum at pH 5 and contact time of 250 min. Adsorption of Pb(II ion with all of adsorbents followed pseudo-second order kinetic equation. Adsorption of Pb(II ion on CTS followed Freundlich isotherm while that on NIP and Pb-IIP followed the Langmuir adsorption isotherm. The adsorbent of Pb-IIP give higher capacity than the NIP and CTS. Adsorption capacity of Pb-IIP, NIP and CTS were 167.1, 128.9 and 76.1 mg/g, respectively. NIP gave higher adsorption selectivity for Pb(II/Ni(II and Pb(II/Cu(II, whereas Pb-IIP showed higher adsorption selectivity for Pb(II/Cd(II.The hydrogen bonding dominated interaction between Pb(II ion on NIP and Pb-IIP.

Synthesis, characterization and antifungal efficacy of C-coordinated O-carboxymethyl chitosan Cu(II) complexes.

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

2017-03-15

A novel type of O-carboxymethyl chitosan Schiff bases (O-CSPX) was synthesized via a condensation reaction. After the coordination reaction of cupric ions, Cu(II) complexes (O-CSPX-Cu) were achieved. The theoretical structure of O-CSPX-Cu calculated by Gaussian 09 reveals that the copper ions underwent dsp 2 hybridization, coordinated by the carbon atom in the p-π conjugate group and the oxygen atoms in the acetate ion. Then, the structures were confirmed by FT-IR, 1 H NMR, CP-MAS 13 C NMR, elemental analysis, DSC and XRD. The antifungal properties of O-CSPX-Cu against Phytophthora capsici (P. capsici), Gibberella zeae (G. zeae) and Glomerella cingulata (G. cingulata) were evaluated at concentrations ranging from 0.05mg/mL to 0.20mg/mL. The experiments indicated that the derivatives have significantly enhanced antifungal activity after copper ion complexation compared with the original chitosan. Moreover, it was shown that 0.20mg/mL of O-CSP3-Cu and O-CSP4-Cu can 100% inhibit the growth of P. capsici. The experimental results reveal that the antifungal efficiency is related to the space steric hindrance on the benzene ring, which may provide a novel direction for the development of copper fungicides. Copyright © 2016 Elsevier Ltd. All rights reserved.

Development of Biomimetic Hybrid Porous Scaffold of Chitosan/Polyvinyl Alcohol/Carboxymethyl Cellulose by Freeze-Dried and Salt Leached Technique.

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Kanimozhi, K; Basha, S Khaleel; Kumari, V Sugantha; Kaviyarasu, K

2018-07-01

Freeze drying and salt leaching methods were applied to fabricate Chitosan/Poly(vinyl alcohol)/Carboxymethyl cellulose (CPCMC) biomimetic porous scaffolds for soft tissue engineering. The properties of these scaffolds were investigated and compared to those by freeze drying and salt leaching methods respectively. The salt-leached CS/PVA/CMC scaffolds were easily formed into desired shapes with a uniformly distributed and interconnected pore structure with an average pore size. The mechanical strength of the scaffolds increased with the porosity, and were easily modulated by the addition of carboxymethyl cellulose. The morphology of the porous scaffolds observed using a SEM exhibited good porosity and interconnectivity of pores. MTT assay using L929 fibroblast cells demonstrated that the cell viability of the porous scaffold was good. Scaffolds prepared by salt leached method show larger swelling capacity, and mechanical strength, potent antibacterial activity and more cell viability than freeze dried method. It is found that salt leaching method has distinguished characteristics of simple, efficient, feasible and less economic than freeze dried scaffolds.

Inter-laboratory verification of European pharmacopoeia monograph on derivative spectrophotometry method and its application for chitosan hydrochloride.

Science.gov (United States)

Marković, Bojan; Ignjatović, Janko; Vujadinović, Mirjana; Savić, Vedrana; Vladimirov, Sote; Karljiković-Rajić, Katarina

2015-01-01

Inter-laboratory verification of European pharmacopoeia (EP) monograph on derivative spectrophotometry (DS) method and its application for chitosan hydrochloride was carried out on two generation of instruments (earlier GBC Cintra 20 and current technology TS Evolution 300). Instruments operate with different versions of Savitzky-Golay algorithm and modes of generating digital derivative spectra. For resolution power parameter, defined as the amplitude ratio A/B in DS method EP monograph, comparable results were obtained only with algorithm's parameters smoothing points (SP) 7 and the 2nd degree polynomial and those provided corresponding data with other two modes on TS Evolution 300 Medium digital indirect and Medium digital direct. Using quoted algorithm's parameters, the differences in percentages between the amplitude ratio A/B averages, were within accepted criteria (±3%) for assay of drug product for method transfer. The deviation of 1.76% for the degree of deacetylation assessment of chitosan hydrochloride, determined on two instruments, (amplitude (1)D202; the 2nd degree polynomial and SP 9 in Savitzky-Golay algorithm), was acceptable, since it was within allowed criteria (±2%) for assay deviation of drug substance, for method transfer in pharmaceutical analyses. Copyright © 2015 Elsevier B.V. All rights reserved.

Carboxymethylated chitosan-stabilized copper nanoparticles: a promise to contribute a potent antifungal and antibacterial agent

Energy Technology Data Exchange (ETDEWEB)

Tantubay, Sangeeta, E-mail: sang.chem2@gmail.com [Indian Institute of Technology Kharagpur, Department of Chemistry (India); Mukhopadhyay, Sourav K. [Indian Institute of Technology Kharagpur, Department of Biotechnology (India); Kalita, Himani; Konar, Suraj [Indian Institute of Technology Kharagpur, Department of Chemistry (India); Dey, Satyahari [Indian Institute of Technology Kharagpur, Department of Biotechnology (India); Pathak, Amita, E-mail: ami@chem.iitkgp.ernet.in; Pramanik, Panchanan, E-mail: ppramanik1946@yahoo.in, E-mail: pramanik1946@gmail.com [Indian Institute of Technology Kharagpur, Department of Chemistry (India)

2015-06-15

Carboxymethylated chitosan (CMC)-stabilized copper nanoparticles (Cu-NPs) have been synthesized via chemical reduction of copper(II)–CMC complex in aqueous medium by hydrazine under microwave irradiation in ambient atmosphere. Structural morphology, phase, and chemical compositions of CMC-stabilized Cu-NPs (CMC–Cu-NPs) have been analyzed through high-resolution transmission electron microscopy, field emission scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Antifungal and antibacterial activities of CMC–Cu-NPs have been evaluated against Candida tropicalis and Escherichia coli through agar well diffusion method, broth microdilution assay, live–dead assay, and microscopic observation. Antimicrobial activity of spherical CMC–Cu-NPs (∼4–15 nm of diameters) has been observed to be significant for both C. tropicalis and E. coli. The cytotoxicity study indicates that CMC–Cu-NPs have no significant toxic effect against normal cell line, L929.

Preparation of an Environmentally Friendly Formulation of the Insecticide Nicotine Hydrochloride through Encapsulation in Chitosan/Tripolyphosphate Nanoparticles.

Science.gov (United States)

Yang, Ying; Cheng, Jiagao; Garamus, Vasil M; Li, Na; Zou, Aihua

2018-02-07

Insecticide nicotine hydrochloride (NCT) was formulated as nanoparticles composed of chitosan (CS) and sodium tripolyphosphate (TPP) to undermine its adverse impacts on human health and reinforce its physicochemical stability. The study investigated the preparation and characterization of chitosan/tripolyphosphate nanoparticles (CS/TPP NPs) with good encapsulation efficiency (55%), uniform morphology, and physicochemical stability (45 days) through dynamic light scattering (DLS), transmission electron microscopy (TEM), and small-angle X-ray scattering (SAXS) measurements. A bioassay against Musca domestica NCT CS/TPP NPs exhibited good bioactivity and thermal stability. The effect of the monovalent salt (NaCl) on manipulating the formation and size distribution of ionically cross-linked nanoparticles was demonstrated as well. The formulation of NCT CS/TPP NPs could be a utility candidate in public health and agriculture.

Synthesis, characterization, and antibacterial activity of N,O-quaternary ammonium chitosan.

Science.gov (United States)

Xu, Tao; Xin, Meihua; Li, Mingchun; Huang, Huili; Zhou, Shengquan; Liu, Juezhao

2011-11-08

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. Copyright © 2011 Elsevier Ltd. All rights reserved.

Application of carboxymethyl cellulose and chitosan coatings containing Mentha spicata essential oil in fresh strawberries.

Science.gov (United States)

Shahbazi, Yasser

2018-06-01

The aim of the present study was to investigate the effects of carboxymethyl cellulose (CMC) and chitosan (CH) coatings containing Mentha spicata essential oil (MSO 0.1 and 0.2%) on survival of Listeria monocytogenes, and physicochemical (weight loss, titratable acidity and pH), microbial (total viable count, psychrotrophic bacteria as well as yeasts and molds) and sensory (appearance, color, texture and overall acceptability) properties of fresh strawberries during refrigerated storage. The treatments of fruits with CH+MSO 0.2% and CMC+MSO 0.2% resulted in the best microbial, physicochemical and organoleptic properties after 12days storage. The final population of L. monocytogenes in treated samples was decreased by 3.92-3.69 compared to control groups. It can be concluded that CH and CMC coatings enriched with MSO can be used as appropriate active packaging materials to preserve fresh strawberries in the food industry. Copyright © 2018 Elsevier B.V. All rights reserved.

Intranasal administration of carbamazepine-loaded carboxymethyl chitosan nanoparticles for drug delivery to the brain

Directory of Open Access Journals (Sweden)

Shanshan Liu

2018-01-01

Full Text Available Epilepsy is considered as a common and diverse set of chronic neurological disorders and its symptoms can be controlled by antiepileptic drugs (AEDs. The presence of p-glycoprotein and multi-drug resistance transporters in the blood-brain barrier could prevent the entry of AEDs into the brain, causing drug resistant epilepsy. To overcome this problem, we propose using carboxymethyl chitosan nanoparticles as a carrier to deliver carbamazepine (CBZ intra-nasally with the purpose to bypass the blood-brain barrier thus to enhance the brain drug concentration and the treatment efficacy. Results so far indicate that the developed CBZ-NPs have small particle size (218.76 ± 2.41 nm with high drug loading (around 35% and high entrapment efficiency (around 80%. The in vitro release profiles of CBZ from the NPs are in accordance with the Korsmeyer-peppas model. The in vivo results show that both encapsulation of CBZ in nanoparticles and the nasal route determined the enhancement of the drug bioavailability and brain targeting characteristics.

Development of carboxymethyl cellulose-chitosan hybrid micro- and macroparticles for encapsulation of probiotic bacteria.

Science.gov (United States)

Singh, P; Medronho, B; Alves, L; da Silva, G J; Miguel, M G; Lindman, B

2017-11-01

Novel carboxymethyl cellulose-chitosan (CMC-Cht) hybrid micro- and macroparticles were successfully prepared in aqueous media either by drop-wise addition or via nozzle-spray methods. The systems were either physically or chemically crosslinked using genipin as the reticulation agent. The macroparticles (ca. 2mm) formed are found to be essentially of the core-shell type, while the microparticles (ca. 5μm) are apparently homogeneous. The crosslinked particles are robust, thermally resistant and less sensitive to pH changes. On the other hand, the physical systems are pH sensitive presenting a remarkable swelling at pH 7.4, while little swelling is observed at pH 2.4. Furthermore, model probiotic bacteria (Lactobacillus rhamnosus GG) was for the first time successfully encapsulated in the CMC-Cht based particles with acceptable viability count. Overall, the systems developed are highly promising for probiotic encapsulation and potential delivery in the intestinal tract with the purpose of modulating gut microbiota and improving human health. Copyright © 2017 Elsevier Ltd. All rights reserved.

Injectable alginate-O-carboxymethyl chitosan/nano fibrin composite hydrogels for adipose tissue engineering.

Science.gov (United States)

Jaikumar, Dhanya; Sajesh, K M; Soumya, S; Nimal, T R; Chennazhi, K P; Nair, Shantikumar V; Jayakumar, R

2015-03-01

Injectable, biodegradable scaffolds are required for soft tissue reconstruction owing to its minimally invasive approach. Such a scaffold can mimic the native extracellular matrix (ECM), provide uniform distribution of cells and overcome limitations like donor site morbidity, volume loss, etc. So, here we report two classes of biocompatible and biodegradable hydrogel blend systems namely, Alginate/O-carboxymethyl chitosan (O-CMC) and Alginate/poly (vinyl alcohol) (PVA) with the inclusion of fibrin nanoparticles in each. The hydrogels were prepared by ionic cross-linking method. The developed hydrogels were compared in terms of its swelling ratio, degradation profile, compressive strength and elastic moduli. From these preliminary findings, it was concluded that Alginate/O-CMC formed a better blend for tissue engineering applications. The potential of the formed hydrogel as an injectable scaffold was revealed by the survival of adipose derived stem cells (ADSCs) on the scaffold by its adhesion, proliferation and differentiation into adipocytes. Cell differentiation studies of fibrin incorporated hydrogel scaffolds showed better differentiation was confirmed by Oil Red O staining technique. These injectable gels have potential in soft tissue regeneration. Copyright © 2014 Elsevier B.V. All rights reserved.

Preparation, property of the complex of carboxymethyl chitosan grafted copolymer with iodine and application of it in cervical antibacterial biomembrane

Energy Technology Data Exchange (ETDEWEB)

Chen, Yu [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Yang, Yumin; Liao, Qingping [Zhejiang Sanchuang Biological Technology Co., Ltd., Jiaxing, Zhejiang Province 314031 (China); Yang, Wei [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Ma, Wanfeng [Zhejiang Sanchuang Biological Technology Co., Ltd., Jiaxing, Zhejiang Province 314031 (China); Zhao, Jian [Department of Gynaecology and Obstetrics, The First Hospital of Peking University, Beijing 100034 (China); Zheng, Xionggao [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Yang, Yang [Zhejiang Sanchuang Biological Technology Co., Ltd., Jiaxing, Zhejiang Province 314031 (China); Chen, Rui [Department of Gynaecology and Obstetrics, The First Hospital of Peking University, Beijing 100034 (China)

2016-10-01

Cervical erosion is one of the common diseases of women. The loop electrosurgical excisional procedure (LEEP) has been used widely in the treatment of the cervical diseases. However, there are no effective wound dressings for the postoperative care to protect the wound area from further infection, leading to increased secretion and longer healing time. Iodine is a widely used inorganic antibacterial agent with many advantages. However, the carrier for stable iodine complex antibacterial agents is lack. In the present study, a novel iodine carrier, Carboxymethyl chitosan-g-(poly(sodium acrylate)-co-polyvinylpyrrolidone) (CMCTS-g-(PAANa-co-PVP), was prepared by graft copolymerization of sodium acrylate (AANa) and N-vinylpyrrolidone (NVP) to a carboxymethyl chitosan (CMCTS) skeleton. The obtained structure could combine prominent property of poly(sodium acrylate) (PAANa) anionic polyelectrolyte segment and good complex property of polyvinylpyrrolidone (PVP) segment to iodine. The bioactivity of CMCTS could also be kept. The properties of the complex, CMCTS-g-(PAANa-co-PVP)-I{sub 2}, were studied. The in vitro experiment shows that it has broad-spectrum bactericidal effects to virus, fungus, gram-positive bacteria and gram-negative bacteria. A CMCTS-g-(PAANa-co-PVP)-I{sub 2} complex contained cervical antibacterial biomembrane (CABM) was prepared. The iodine release from the CABM is pH-dependent. The clinic trial results indicate that CABM has better treatment effectiveness than the conventional treatment in the postoperative care of the LEEP operation. - Highlights: • The multifunctional iodine complexing carrier CMCTS-g-(PAANa-co-PVP) was prepared. • CMCTS-g-(PAANa-co-PVP)-I{sub 2} with high antibacterial property and bio-safety was studied. • By compositing it with CMCTS and gelatin further, CABM with multifunction was deduced. • The releasing properties of the activated iodine from CABM showed pH sensitivity. • CABM showed good treating effect for

Hemostatic foam from radiation-modified carboxymethyl derivative of chitosan

International Nuclear Information System (INIS)

Barba, Bin Jeremiah D.; Aranilla, Charito T.; Vista, Jeanina Richelle M.; Relleve, Lorna S.; Abad, Lucille V.

2015-01-01

A hemostatic agent or hemostat is intended to accelerate the blood clotting process when applied to a bleeding surface, such as those in military and civilian wound trauma or in surgery. Natural polymers like chitosan (Ch) has been previously used as raw material in developing hemostats owing to their bioavailability and biocompatibility. Hydrogels were made from its carboxymethylated derivate (CMCh) and were crosslinked by gamma irradiation at a dose of 30 kGy. Further processing was done by salt leaching with sodium chloride and lyophilization to produce the foam hemostat. The final products were then radiation-sterilized at 25 kGy. The use of gamma radiation for both the crosslinking and sterilization process preserves the biocompatibility of the product unlike conventional methods that may require the use of harmful and non-biocompatible chemicals. The hemostatic efficacy of the designed foam hemostats was compared to the commercially available foam hemostat, GELFOAM Sterile Compressed Sponge by Pfizer. The results showed a significantly higher efficiency of the designed products using in vitro test to determine blood clotting index and platelet adhesion capacity. Characterization by gel fraction, swelling capacity and SEM imaging indicated a hydrophilic three-dimensional network which can be attributed for the thrombogenicity of the foams produced. The foam structure can act as a physical matrix for platelet adhesion forming the mechanical plug and at the same time, rapidly absorb water thereby locally increasing the concentration of platelets and physiological coagulation factors that will contribute to quick and efficient hemostasis. The designed products will provide the healthcare and military sector with a local alternative to the commercial products which are both expensive (USD 85 per piece) and not readily accessible in the Philippine market. Further animal efficacy and biocompatibility studies are recommended to supplement the positive in vitro

Bifunctional coating based on carboxymethyl chitosan with stable conjugated alkaline phosphatase for inhibiting bacterial adhesion and promoting osteogenic differentiation on titanium

Energy Technology Data Exchange (ETDEWEB)

Zheng, Dong; Neoh, Koon Gee, E-mail: chenkg@nus.edu.sg; Kang, En-Tang

2016-01-01

Graphical abstract: - Highlights: • Alkaline phosphatase was immobilized on carboxymethyl chitosan coating on Ti. • The coating is bifunctional; resists bacterial adhesion and enhances cell functions. • Osteogenic differentiation of osteoblasts and stem cells is enhanced on the coating. • The coating remains stable and functional after ethanol treatment and autoclaving. - Abstract: In this work, alkaline phosphatase (ALP) was covalently immobilized on carboxymethyl chitosan (CMCS)-coated polydopamine (PDA)-functionalized Ti to achieve a bifunctional surface. Our results showed ∼89% reduction in Staphylococcus epidermidis adhesion on this surface compared to that on pristine Ti. The ALP-modified Ti supported cell proliferation, and significantly enhanced cellular ALP activity and calcium deposition of osteoblasts, human mesenchymal stem cells (hMSCs) and human adipose-derived stem cells (hADSCs). The extent of enhancement in the functions of these cells is dependent on the surface density of immobilized ALP. The substrate prepared using an ALP solution of 50 μg/cm{sup 2} resulted in 44%, 54% and 129% increase in calcium deposited by osteoblasts, hMSCs and hADSCs, respectively, compared to those cultured on pristine Ti. The ALP-modified substrates also promoted the osteogenic differentiation of hMSCs and hADSCs by up-regulating gene expressions of runt-related transcription factor 2 (RUNX2), osterix (OSX), and osteocalcin (OC) in the two types of stem cells. The surface-immobilized ALP was stable after being subjected to 1 h immersion in 70% ethanol and autoclaving at 121 °C for 20 min. However, the enzymatic bioactivity of the surface-immobilized ALP was reduced by about 50% after these substrates were immersed in phosphate buffered saline (PBS) or PBS containing lysozyme for 14 days.

O-Carboxymethyl Chitosan Supported Heterogeneous Palladium and Ni Catalysts for Heck Reaction

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Dongjun Lv

2017-01-01

Full Text Available Two polymer catalysts (Pd-OCMCS and Ni-OCMCS with good reusability were synthesized by coordinating Pd and Ni onto O-carboxymethyl chitosan (OCMCS. The chemical structure and thermal stability of prepared catalysts were determined by Fourier transform infrared (FT-IR spectra, Energy Dispersive Spectrometer (EDSanalysis, X-ray diffraction (XRD, and thermogravimetric analyzer (TG-DTG, and the analysis results showed that the Pd and Ni ions coordinated onto the OCMCS and formed a ligand with the –COOH group, amino groups, and –OH group on the OCMCS, and the EDS and Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES analysis results showed that the loading amounts of Pd and Ni were approximately 8.3% and 8.9%, respectively. In the Heck reaction between aryl halides and n-butyl acrylate catalyzed by the prepared catalyst, the test results showed that the product yield followed the order of aryl iodide > aryl bromide > aryl chloride. Additionally, the product yield for the aryl iodide and aryl bromide could reach up to 99% and 96%, respectively. Moreover, the electron-withdrawing and electron-donating property of the group on the aryl also affected the product yield, and the product yield for aryl halides with electron-withdrawing group p-NO2, p-CH3CO, and p-CHO was higher than that with electron-donating group p-CH3.

Injectable self-healing carboxymethyl chitosan-zinc supramolecular hydrogels and their antibacterial activity.

Science.gov (United States)

Wahid, Fazli; Zhou, Ya-Ning; Wang, Hai-Song; Wan, Tong; Zhong, Cheng; Chu, Li-Qiang

2018-04-07

Injectable and self-healing hydrogels have found numerous applications in drug delivery, tissue engineering and 3D cell culture. Herein, we report an injectable self-healing carboxymethyl chitosan (CMCh) supramolecular hydrogels cross-linked by zinc ions (Zn 2+ ). Supramolecular hydrogels were obtained by simple addition of metal ions solution to CMCh solution at an appropriate pH value. The mechanical properties of these hydrogels were adjustable by the concentration of Zn 2+ . For example, the hydrogel with the highest concentration of Zn 2+ (CMCh-Zn4) showed strongest mechanical properties (storage modulus~11,000Pa) while hydrogel with the lowest concentration of Zn 2+ (CMCh-Zn1) showed weakest mechanical properties (storage modulus~220Pa). As observed visually and confirmed rheologically, the CMCh-Zn1 hydrogel with the lowest Zn 2+ concentration showed thixotropic property. CMCh-Zn1 hydrogel also presented injectable property. Moreover, the antibacterial properties of the prepared supramolecular hydrogels were studied against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) by agar well diffusion method. The results revealed Zn 2+ dependent antibacterial properties against both kinds of strains. The inhibition zones were ranging from ~11-24mm and ~10-22mm against S. aureus and E. coli, respectively. We believe that the prepared supramolecular hydrogels could be used as a potential candidate in biomedical fields. Copyright © 2018 Elsevier B.V. All rights reserved.

The pH sensitive properties of carboxymethyl chitosan nanoparticles cross-linked with calcium ions.

Science.gov (United States)

Kalliola, Simo; Repo, Eveliina; Srivastava, Varsha; Heiskanen, Juha P; Sirviö, Juho Antti; Liimatainen, Henrikki; Sillanpää, Mika

2017-05-01

In environmental applications the applied materials are required to be non-toxic and biodegradable. Carboxymethyl chitosan nanoparticles cross-linked with Ca 2+ ions (CMC-Ca) fulfill these requirements, and they are also renewable. These nanoparticles were applied to oil-spill treatment in our previous study and here we focused on enhancing their properties. It was found that while the divalent Ca 2+ ions are crucial for the formation of the CMC-Ca, the attractive interaction between NH 3 + and COO - groups contributed significantly to the formation and stability of the CMC-Ca. The stability decreased as a function of pH due to the deprotonation of the amino groups. Therefore, the nanoparticles were found to be fundamentally pH sensitive in solution, if the pH deviated from the pH (7-9) that was used in the synthesis of the nanoparticles. The pH sensitive CMC-Ca synthesized in pH 7 and 8 were most stable in the studied conditions and could find applications in oil-spill treatment or controlled-release of substances. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Bioactive and metal uptake studies of carboxymethyl chitosan-graft-D-glucuronic acid membranes for tissue engineering and environmental applications.

Science.gov (United States)

Jayakumar, R; Rajkumar, M; Freitas, H; Sudheesh Kumar, P T; Nair, S V; Furuike, T; Tamura, H

2009-08-01

Carboxymethyl chitosan-graft-D-glucuronic acid (CMCS-g-D-GA) was prepared by grafting D-GA onto CMCS in the presence of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and then the membranes were made from it. In this work, the bioactivity studies of CMCS-g-D-GA membranes were carried out and then characterized by SEM, CLSM, XRD and FT-IR. The CMCS-g-D-GA membranes were found to be bioactive. The adsorption of Ni2+, Zn2+ and Cu2+ ions onto CMCS-g-D-GA membranes has also been investigated. The maximum adsorption capacity of CMCS-g-D-GA for Ni2+, Zn2+ and Cu2+ was found to be 57, 56.4 and 70.2 mg/g, respectively. Hence, these membranes were useful for tissue engineering, environmental and water purification applications.

Further investigation on the degree of deacetylation of chitosan determined by potentiometric titration

OpenAIRE

Kamal Sweidan; Abdel-Motalleb Jaber; Nawzat Al-jbour; Rana Obaidat; Mayyas Al- Remawi; Adnan Badwan

2011-01-01

The degree of deacetylation (DDA) of various low molecular weight chitosan (LMWC) species as the hydrochloride and free base (amine form) was determined by direct and back potentiometric titration, respectively. The DDA values obtained for the chitosan hydrochloride by direct titration were greater than 93% for all oligomers tested (Molecular weight (Mwt) between about 1.3 to 30.0 kDa). However, the DDA values obtained for chitosan amine oligomers using back titration were significantly lower...

Synthesis of (2-pyridyl)-Acetyl Chitosan and Its Antioxidant Activity

International Nuclear Information System (INIS)

Li, Rongchun

2011-01-01

In this paper, chloracetyl chitosan (CACTS) was prepared at first. In the molecules of CACTS, there are active chlorine groups, which can take part in other reactions. Thus, number of chitosan derivatives will be obtained after chlorine is substituted. Choosing pyridine as the active group, a novel water-soluble chitosan derivative, (2-pyridyl)-acetyl chitosan (PACTS) was obtained and its antioxidant activity against hydroxyl radicals and superoxide radicals was assessed. The results indicated that PACTS had better antioxidant activity than that of chitosan, carboxymethyl chitosan (CMCTS), hydroxypropyl chitosan (HPCTS), and Vitamin C. And the IC 50 values against hydroxyl radicals and superoxide radicals were 0.31 mg/mL and 0.21 mg/mL, respectively

Curcumin-carboxymethyl chitosan (CNC) conjugate and CNC/LHR mixed polymeric micelles as new approaches to improve the oral absorption of P-gp substrate drugs.

Science.gov (United States)

Ni, Jiang; Tian, Fengchun; Dahmani, Fatima Zohra; Yang, Hui; Yue, Deren; He, Shuwang; Zhou, Jianping; Yao, Jing

2016-11-01

The low oral bioavailability of numerous drugs has been mostly attributed to the significant effect of P-gp-mediated efflux on intestinal drug transport. Herein, we developed mixed polymeric micelles (MPMs) comprised of curcumin-carboxymethyl chitosan (CNC) conjugate, as a potential inhibitor of P-gp-mediated efflux and gastrointestinal absorption enhancer, and low-molecular-weight heparin-all-trans-retinoid acid (LHR) conjugate, as loading material, with the aim to improve the oral absorption of P-gp substrate drugs. CNC conjugate was synthesized by chemical bonding of curcumin (Cur) and carboxymethyl chitosan (CMCS) taking advantage of the inhibition of intestinal P-gp-mediated secretion by Cur and the intestinal absorption enhancement by CMCS. The chemical structure of CNC conjugate was characterized by 1 H NMR with a degree of substitution of Cur of 4.52-10.20%. More importantly, CNC conjugate markedly improved the stability of Cur in physiological pH. Cyclosporine A-loaded CNC/LHR MPMs (CsA-CNC/LHR MPMs) were prepared by dialysis method, with high drug loading 25.45% and nanoscaled particle size (∼200 nm). In situ single-pass perfusion studies in rats showed that both CsA + CNC mixture and CsA-CNC/LHR MPMs achieved significantly higher K a and P eff than CsA suspension in the duodenum and jejunum segments (p CNC mixture and CsA-CNC/LHR MPMs significantly increased the oral bioavailability of CsA as compared to CsA suspension. These results suggest that CNC conjugate might be considered as a promising gastrointestinal absorption enhancer, while CNC/LHR MPMs had the potential to improve the oral absorption of P-gp substrate drugs.

Synthesis, characterization and application of biodegradable crosslinked carboxymethyl chitosan/poly(vinyl alcohol) clay nanocomposites

Energy Technology Data Exchange (ETDEWEB)

Sabaa, Magdy W.; Abdallah, Heba M.; Mohamed, Nadia A.; Mohamed, Riham R., E-mail: rihamrashad@hotmal.com

2015-11-01

Crosslinked poly(vinyl alcohol) (PVA)/carboxymethyl chitosan (CMCh) nanocomposites were synthesized using terephthaloyl diisothiocyanate crosslinker, in the presence of montmorillonite (MMT), in different ratios of the two matrices. Characterization of nanocomposites was performed using different analyses. Swelling behavior was studied in different buffered solutions. It was found that formation of crosslinked CMCh/PVA hydrogels increased the swellability. Metal ion adsorption has also been investigated. The results indicated that crosslinked CMCh adsorbs various metal ions much more than non crosslinked CMCh. Antimicrobial activity was examined against Gram positive bacteria, against Gram negative bacteria, and also against fungi. Results indicated that most of these nanocomposites exhibited good antimicrobial potency. Degradation study was carried out in Simulated Body Fluid (SBF) for different time periods in order to find out degradation index (Di). Results showed that weight loss of most of the nanocomposites increased as a function of incubation time. - Highlights: • CMCh/PVA nanocomposites have been evaluated for activity against bacteria and fungi. • TEM showed that these hydrogels have size 3–19 nm. • Nanocomposites increased metal ion uptake and showed selectivity for cadmium ions. • Biodegradation increased as a function of incubation time in SBF solution. • Biodegradation increased with increase in CMCh and clay in nanocomposites.

Synthesis and characterization of carboxymethyl chitosan hydrogel ...

Indian Academy of Sciences (India)

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

Structure formation in pH-sensitive hydrogels composed of sodium caseinate and N,O-carboxymethyl chitosan.

Science.gov (United States)

Wei, Yanxia; Xie, Rui; Lin, Yanbin; Xu, Yunfei; Wang, Fengxia; Liang, Wanfu; Zhang, Ji

2016-08-01

The pH-sensitive hydrogels composed of sodium caseinate (SC) and N,O-carboxymethyl chitosan (NOCC) were prepared and a new method to characterize the gelation process was presented in this work. Reological tests suggested that RSC/NOCC=3/7 (the weight ratio of SC and NOCC) was the best ratio of hydrogel. The well-developed three-dimensional network structures in the hydrogel were confirmed by AFM. Two structural parameters, tIS and tCS, denoted as the initial and critical structure formation time, respectively, were used to provide an exact determination of the start of structure formation and description of gelation process. The gelation process strongly depended on temperature changes, a high temperature resulted in an early start of gelation. The non-kinetic model suggested the higher activation energy in the higher temperatures was disadvantageous to structure formation, and vice versa. Due to the smart gel reported here was very stable at room temperature, we believed that the gel is required for applications in drug delivery or could be exploited in the development of potential application as molecular switches in the future. Copyright © 2016 Elsevier B.V. All rights reserved.

Enzymatically crosslinked carboxymethyl-chitosan/gelatin/nano-hydroxyapatite injectable gels for in situ bone tissue engineering application

Energy Technology Data Exchange (ETDEWEB)

Mishra, Debasish; Bhunia, Bibhas; Banerjee, Indranil [Department of Biotechnology, Indian Institute of Technology Kharagpur (India); Datta, Pallab; Dhara, Santanu [School of Medical Science and Technology, Indian Institute of Technology Kharagpur (India); Maiti, Tapas K., E-mail: maititapask@gmail.com [Department of Biotechnology, Indian Institute of Technology Kharagpur (India)

2011-10-10

Present study reports synthesis and characterization of an enzymatically crosslinked injectable gel (iGel) suitable for cell based bone tissue engineering application. The gel comprises of carboxymethyl-chitosan (CMC)/gelatin/nano-hydroxyapatite (nHAp) susceptible to tyrosinase/p-cresol mediated in situ gelling at physiological temperature. Study revealed that a combination of tyrosinase (60U) and p-cresol (2 mM) as crosslinking agents yield rigid gels at physiological temperature when applied to CMC/gelatin within 35 min in presence or absence of nHAp. Rheological study in conjugation with FT-IR analysis showed that an increase in CMC concentration in the gel leads to higher degree of crosslinking and higher strength. Scanning electron microscopy showed that pore sizes of iGels increased with higher gelatin concentration. In vitro study of osteoblast cell proliferation and differentiation showed that, although all iGels are supportive towards the growth of primary osteoblast cells, GC1:1 supported cellular differentiation to the maximum. Application of iGels in mice revealed that stability of the in situ formed gels depends on the degree of crosslinking and CMC concentration. In conclusion, the iGels may be used in treating irregular small bone defects with minimal clinical invasion as well as for bone cell delivery. - Research Highlights: {yields} Enzymatically crosslinked injectable gel made up of CM-chitosan (C)/gelatin (G)/nHAp. {yields} Tyrosinase/p-cresol used for crosslinking and in situ gelling of polymers at 37deg. C. {yields} 60U tyrosinase and 2mM p-cresol is needed for gelation in 35 min. {yields} Higher GC ratio manifests lower crosslinking and gel strength but higher porosity. {yields} GC1:1 shows maximum in vivo gel stability and in vitro osteoblast differentiation.

Effects of Incorporating Carboxymethyl Chitosan into PMMA Bone Cement Containing Methotrexate.

Directory of Open Access Journals (Sweden)

Bo-Ming Liu

Full Text Available Treatment of bone metastases usually includes surgical resection with local filling of methotrexate (MTX in polymethyl methacrylate (PMMA cement. We investigated whether incorporating carboxymethyl chitosan (CMCS in MTX-PMMA cement might overcome disadvantages associated with MTX. To determine the optimal CMCS+MTX concentration to suppress the viability of cancer cells, an integrated microfluidic chip culturing highly metastatic lung cancer cells (H460 was employed. The mechanical properties, microstructure, and MTX release of (CMCS+MTX-PMMA cement were evaluated respectively by universal mechanical testing machine, scanning electron microscopy (SEM, and incubation in simulated body fluid with subsequent HPLC-MS. Implants of MTX-PMMA and (CMCS+MTX-PMMA cement were evaluated in vivo in guinea pig femurs over time using spiral computed tomography with three-dimensional image reconstruction, and SEM at 6 months. Viability of H460 cells was significantly lowest after treatment with 57 μg/mL CMCS + 21 μg/mL MTX, which was thus used in subsequent experiments. Incorporation of 1.6% (w/w CMCS to MTX-PMMA significantly increased the bending modulus, bending strength, and compressive strength by 5, 2.8, and 5.2%, respectively, confirmed by improved microstructural homogeneity. Incorporation of CMCS delayed the time-to-plateau of MTX release by 2 days, but increased the fraction released at the plateau from 3.24% (MTX-PMMA to 5.34%. Relative to the controls, the (CMCS+MTX-PMMA implants integrated better with the host bone. SEM revealed pores in the cement of the (CMCS+MTX-PMMA implants that were not obvious in the controls. In conclusion, incorporation of CMCS in MTX-PMMA appears a feasible and effective modification for improving the anti-tumor properties of MTX-PMMA cement.

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

Science.gov (United States)

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

2016-11-20

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

Enhancement of Egyptian soft white cheese shelf life using a novel chitosan/carboxymethyl cellulose/zinc oxide bionanocomposite film.

Science.gov (United States)

Youssef, Ahmed M; El-Sayed, Samah M; El-Sayed, Hoda S; Salama, Heba H; Dufresne, Alain

2016-10-20

A novel bionanocomposites packaging material prepared using chitosan (CH), carboxymethyl cellulose (CMC), and zinc oxide nanoparticles (ZnO-NPs), namely CH/CMC/ZnO bionanocomposites, was prepared by casting method. The CH/CMC/ZnO bionanocomposites were investigated using FT-IR, TEM, SEM, XRD, and TGA. The acquired bionanocomposites exhibited improved mechanical and thermal properties compare with the biocomposites (CH/CMC) blend. The soft white cheese were manufactured, packaged within the prepared bionanocomposites films and stored at 7°C for 30days. The influence of packaging material on packaged cheese (rheological properties, colour measurements, moisture, pH and titratable acidity) were assessed. Furthermore, the effect of packaging material on the total bacterial counts, mold & yeast and coliform in cheese was evaluated. The prepared bionanocomposites displayed good antibacterial activity against gram positive (Staphylococcus aureus), gram negative (Pseudomonas aeruginosa, Escherichia coli) bacteria and fungi (Candidia albicans). Moreover, the packaging films assisted in increasing the shelf life of white soft cheese. Therefore, it can be used in food packaging applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

Chitosan-thioglycolic acid as a versatile antimicrobial agent.

Science.gov (United States)

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

2013-04-08

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

A novel ultrasensitive carboxymethyl chitosan-quantum dot-based fluorescence "turn on-off" nanosensor for lysozyme detection.

Science.gov (United States)

Song, Yu; Li, Yang; Liu, Ziping; Liu, Linlin; Wang, Xinyan; Su, Xingguang; Ma, Qiang

2014-11-15

In this work, we developed an ultrasensitive "turn on-off" fluorescence nanosensor for lysozyme (Lyz) detection. The novel nanosensor was constructed with the carboxymethyl chitosan modified CdTe quantum dots (CMCS-QDs). Firstly, the CMCS-QDs were fabricated via the electrostatic interaction between amino groups in CMCS polymeric chains and carboxyl groups on the surface of QDs. In the fluorescence "turn-on" step, the strong binding ability between Zn(2+) and CMCS on the surface of QDs can enhance the photoluminescence intensity (PL) of QDs. In the following fluorescence "turn-off" step, the N-acetyl-glucosamine (NAG) section along the CMCS chains was hydrolyzed by Lyz. As a result, Zn(2+) was released from the surface of QDs, and the Lyz-QDs complexes were formed to quench the QDs PL. Under the optimal conditions, there was a good linear relationship between the PL of QDs and the Lyz concentration (0.1-1.2 ng/mL) with the detection limit of 0.031 ng/mL. The developed method was ultrasensitive, highly selective and fast. It has been successfully employed in the detection of Lyz in the serum with satisfactory results. Copyright © 2014 Elsevier B.V. All rights reserved.

Chitosan and Its Derivatives for Application in Mucoadhesive Drug Delivery Systems

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Twana Mohammed M. Ways

2018-03-01

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

A label-free fluorescence biosensor for highly sensitive detection of lectin based on carboxymethyl chitosan-quantum dots and gold nanoparticles

International Nuclear Information System (INIS)

Liu, Ziping; Liu, Hua; Wang, Lei; Su, Xingguang

2016-01-01

In this work, we report a novel label-free fluorescence “turn off-on” biosensor for lectin detection. The highly sensitive and selective sensing system is based on the integration of carboxymethyl chitosan (CM-CHIT), CuInS_2 quantum dots (QDs) and Au nanoparticles (NPs). Firstly, CuInS_2 QDs featuring carboxyl groups were directly synthesized via a hydrothermal synthesis method. Then, the carboxyl groups on the CuInS_2 QDs surface were interacted with the amino groups (−NH_2), carboxyl groups (−COOH) and hydroxyl groups (−OH) within CM-CHIT polymeric chains via electrostatic interactions and hydrogen bonding to form CM-CHIT-QDs assemblies. Introduction of Au NPs could quench the fluorescence of CM-CHIT-QDs through electron and energy transfer. In the presence of lectin, lectin could bind exclusively with CM-CHIT-QDs by means of specific multivalent carbohydrate-protein interaction. Thus, the electron and energy transfer process between CM-CHIT-QDs and Au NPs was inhibited, and as a result, the fluorescence of CM-CHIT-QDs was effectively “turned on”. Under the optimum conditions, there was a good linear relationship between the fluorescence intensity ratio I/I_0 (I and I_0 were the fluorescence intensity of CM-CHIT-QDs-Au NPs in the presence and absence of lectin, respectively) and lectin concentration in the range of 0.2–192.5 nmol L"−"1, And the detection limit could be down to 0.08 nmol L"−"1. Furthermore, the proposed biosensor was employed for the determination of lectin in fetal bovine serum samples with satisfactory results. - Graphical abstract: A label-free fluorescence biosensor for highly sensitive detection of lectin based on the integration of carboxymethyl chitosan, CuInS_2 quantum dots and gold nanoparticles. - Highlights: • A label-free near-infrared fluorescence “turn off-on” biosensor for detection of lectin was established. • The highly sensitive biosensor was based on the inner filter effect of Au NPs on CM

A label-free fluorescence biosensor for highly sensitive detection of lectin based on carboxymethyl chitosan-quantum dots and gold nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Liu, Ziping; Liu, Hua; Wang, Lei; Su, Xingguang, E-mail: suxg@jlu.edu.cn

2016-08-17

In this work, we report a novel label-free fluorescence “turn off-on” biosensor for lectin detection. The highly sensitive and selective sensing system is based on the integration of carboxymethyl chitosan (CM-CHIT), CuInS{sub 2} quantum dots (QDs) and Au nanoparticles (NPs). Firstly, CuInS{sub 2} QDs featuring carboxyl groups were directly synthesized via a hydrothermal synthesis method. Then, the carboxyl groups on the CuInS{sub 2} QDs surface were interacted with the amino groups (−NH{sub 2}), carboxyl groups (−COOH) and hydroxyl groups (−OH) within CM-CHIT polymeric chains via electrostatic interactions and hydrogen bonding to form CM-CHIT-QDs assemblies. Introduction of Au NPs could quench the fluorescence of CM-CHIT-QDs through electron and energy transfer. In the presence of lectin, lectin could bind exclusively with CM-CHIT-QDs by means of specific multivalent carbohydrate-protein interaction. Thus, the electron and energy transfer process between CM-CHIT-QDs and Au NPs was inhibited, and as a result, the fluorescence of CM-CHIT-QDs was effectively “turned on”. Under the optimum conditions, there was a good linear relationship between the fluorescence intensity ratio I/I{sub 0} (I and I{sub 0} were the fluorescence intensity of CM-CHIT-QDs-Au NPs in the presence and absence of lectin, respectively) and lectin concentration in the range of 0.2–192.5 nmol L{sup −1}, And the detection limit could be down to 0.08 nmol L{sup −1}. Furthermore, the proposed biosensor was employed for the determination of lectin in fetal bovine serum samples with satisfactory results. - Graphical abstract: A label-free fluorescence biosensor for highly sensitive detection of lectin based on the integration of carboxymethyl chitosan, CuInS{sub 2} quantum dots and gold nanoparticles. - Highlights: • A label-free near-infrared fluorescence “turn off-on” biosensor for detection of lectin was established. • The highly sensitive biosensor was based on the

[Preparation and physicochemical property of carboxymethyl-chitosan/hyaluronic acid poly(vinyl alcohol) blend membrane].

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Liu, Wen; Li, Shuning; Chang, Jing; Han, Baoqin; Liu, Wanshun

2009-08-01

To prepare carboxymethyl-chitosan/hyaluronic acid/poly(vinyl alcohol) (CHP) blend membrane, evaluate its physicochemical properties and intraocular biocompatibility and to investigate its feasibility to be applied to glaucoma filtering surgery. CHP blend membrane was prepared using solution casting method after blending carboxymethyl-chitosan, HA and poly(vinyl alcohol) in a proportion of 5 : 4 : 1 (M/M). Its water absorption rate, swelling rate, permeability, and mechanical properties were detected. Subconjunctival fibroblasts separated from subconjunctival tissue of New Zealand white rabbits were cultured, and the cells at passage 4 were cultured on cell culture plate with or without the CHP blend membrane, serving as the experimental group and the control group, respectively. Effect of the CHP blend membrane on the subconjunctival fibroblasts was tested by MTT method 24, 48, and 72 hours after culture. Six New Zealand white rabbits were randomly divided into two groups (n = 3 rabbits per group), and the CHP blend membrane and SK gel were implanted into the rabbits' subconjunctival space and anterior chamber in the experimental group and the control group, respectively. Slit lamp observation and binocular reaction record were conducted 1, 3, 5, 9, 11, 20, 30, 45, and 60 days after operation. Corneal tissue harvested from the experimental group was observed using scanning electron microscope 15 days after operation to study ophthalmic biocompatibility and biodegradability. The water absorption rate and the swelling rate of the CHP blend membrane was 83.8% +/- 1.3% and 3.59 +/- 0.50, respectively. The tensile strength of the dry and the wet CHP blend membrane was (20.59 +/- 1.73) and (0.51 +/- 0.13) MPa, respectively. The breaking elongation rate of the dry and the wet CHP blend membrane was 10.69% +/- 1.16% and 53.15% +/- 2.46%, respectively. The CHP blend membrane had good permeability to NaCl and L-tyrosine. Absorbance (A) value of the experimental group 24, 48

Simultaneously Toughening and Strengthening Soy Protein Isolate-Based Composites via Carboxymethylated Chitosan and Halloysite Nanotube Hybridization

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Xiaorong Liu

2017-06-01

Full Text Available Chemical cross-linking modification can significantly enhance the tensile strength (TS of soy protein isolate (SPI-based composites, but usually at the cost of a reduction in the elongation at break (EB. In this study, eco-friendly and high-potential hybrid SPI-based nanocomposites with improved TS were fabricated without compromising the reduction of EB. The hybrid of carboxymethylated chitosan (CMCS and halloysite nanotubes (HNTs as the enhancement center was added to the SPI and 1,2,3-propanetriol-diglycidyl-ether (PTGE solution. The chemical structure, crystallinity, micromorphology, and opacity properties of the obtained SPI/PTGE/HNTs/CMCS film was analyzed by the attenuated total reflectance-Fourier transform infrared (ATR-FTIR spectroscopy, X-ray photoelectron spectroscopy (XPS, X-ray diffraction (XRD, scanning electron microscopy (SEM, atomic force microscopy (AFM, and UV-Vis spectroscopy. The results indicated that HNTs were uniformly dispersed in the SPI matrix without crystal structure damages. Compared to the SPI/PTGE film, the TS and EB of the SPI/PTGE/HNTs/CMCS film were increased by 57.14% and 27.34%, reaching 8.47 MPa and 132.12%, respectively. The synergy of HNTs and CMCS via electrostatic interactions also improved the water resistance of the SPI/PTGE/HNTs/CMCS film. These films may have considerable potential in the field of sustainable and environmentally friendly packaging.

Effect of concentration and molecular weight of chitosan and its derivative on the free radical scavenging ability.

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Li, Huili; Xu, Qing; Chen, Yun; Wan, Ajun

2014-03-01

Chitosan is a biodegradable and biocompatible natural scaffold material, which has numerous applications in biomedical sciences. In this study, the in vitro antioxidant activity of chitosan scaffold material was investigated by the chemiluminescence signal generated from the hydroxyl radical (•OH) scavenging assay. The scavenging mechanism was also discussed. The results indicated that the free radical scavenging ability of chitosan scaffold material significantly depends on the chitosan concentration and shows interesting kinetic change. Within the experimental concentration range, the optimal concentration of chitosan was 0.2 mg/mL. The molecular weight of chitosan also attributed to the free radical scavenging ability. Comparison between chitosan and its derivative found that carboxymethyl chitosan possessed higher scavenging ability. Copyright © 2013 Society of Plastics Engineers.

Effect of chitosan and its derivatives as antifungal and preservative agents on postharvest green asparagus.

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Qiu, Miao; Wu, Chu; Ren, Gerui; Liang, Xinle; Wang, Xiangyang; Huang, Jianying

2014-07-15

The antifungal activity and effect of high-molecular weight chitosan (H-chitosan), low-molecular weight chitosan (L-chitosan) and carboxymethyl chitosan (C-chitosan) coatings on postharvest green asparagus were evaluated. L-chitosan and H-chitosan efficiently inhibited the radial growth of Fusarium concentricum separated from postharvest green asparagus at 4 mg/ml, which appeared to be more effective in inhibiting spore germination and germ tube elongation than that of C-chitosan. Notably, spore germination was totally inhibited by L-chitosan and H-chitosan at 0.05 mg/ml. Coated asparagus did not show any apparent sign of phytotoxicity and maintained good quality over 28 days of cold storage, according to the weight loss and general quality aspects. Present results inferred that chitosan could act as an attractive preservative agent for postharvest green asparagus owing to its antifungal activity and its ability to stimulate some defense responses during storage. Copyright © 2014 Elsevier Ltd. All rights reserved.

Chitosan, the Marine Functional Food, Is a Potent Adsorbent of Humic Acid

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Chao-Lin Liu

2011-11-01

Full Text Available 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.

Novel ionically crosslinked acrylamide-grafted poly(vinyl alcohol)/sodium alginate/sodium carboxymethyl cellulose pH-sensitive microspheres for delivery of Alzheimer's drug donepezil hydrochloride: Preparation and optimization of release conditions.

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Bulut, Emine; Şanlı, Oya

2016-01-01

In this work, the graft copolymer, poly(vinyl alcohol)-grafted polyacrylamide (PVA-g-PAAm), was synthesized and characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, and elemental analysis. Microspheres of PVA-g-PAAm/sodium alginate (NaAlg)/sodium carboxymethyl cellulose (NaCMC) were prepared by the emulsion-crosslinking method and used for the delivery of an Alzheimer's drug, donepezil hydrochloride (DP). The release of DP increased with the increase in drug/polymer ratio (d/p) and PVA-g-PAAm/NaAlg/NaCMC ratio, while it decreased with the increase in the extent of crosslinking. The optimum DP release was obtained as 92.9% for a PVA-g-PAAm/NaAlg/NaCMC ratio of 1/2/1, d/p ratio of 1/8, and FeCl3 concentration of 7% (w/v).

Preparation of a Facilitated Transport Membrane Composed of Carboxymethyl Chitosan and Polyethylenimine for CO2/N2 Separation

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Jiang-Nan Shen

2013-02-01

Full Text Available The miscibility of carboxymethyl chitosan/polyethylenimine (CMCS/PEI blends was analyzed by FT-IR, TGA and SEM. Defect-free CMCS/PEI blend membranes were prepared with polysulfone (PSf ultrafiltration membranes as support layer for the separation of CO2/N2 mixtures. The results demonstrate that the CMCS/PEI blend is miscible, due to the hydrogen bonding interaction between the two targeted polymers. For the blended membrane without water, the permeability of CO2 gas is 3.6 × 10−7 cm3 cm−2 s−1 cmHg−1 and the corresponding separation factor for CO2 and N2 gas is about 33 at the pressure of 15.2 cmHg. Meanwhile, the blended membrane with water has the better permselectivity. The blended membrane containing water with PEI content of 30 wt% has the permeance of 6.3 × 10−4 cm3 cm−2 s−1 cmHg−1 for CO2 gas and a separation factor of 325 for CO2/N2 mixtures at the same feed pressure. This indicates that the CO2 separation performance of the CMCS/PEI blend membrane is higher than that of other facilitated transport membranes reported for CO2/N2 mixture separation.

Sodium Carboxymethyl Chitosan as a Fixative for Eau de Cologne

African Journals Online (AJOL)

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

The Influence of Chitosan Cross-linking on the Properties of Alginate Microparticles with Metformin Hydrochloride—In Vitro and In Vivo Evaluation

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Marta Szekalska

2017-01-01

Full Text Available Sodium alginate is a polymer with unique ability to gel with different cross-linking agents in result of ionic and electrostatic interactions. Chitosan cross-linked alginate provides improvement of swelling and mucoadhesive properties and might be used to design sustained release dosage forms. Therefore, the aim of this research was to develop and evaluate possibility of preparing chitosan cross-linked alginate microparticles containing metformin hydrochloride by the spray-drying method. In addition, influence of cross-linking agent on the properties of microparticles was evaluated. Formulation of microparticles prepared by the spray drying of 2% alginate solution cross-linked by 0.1% chitosan was characterized by good mucoadhesive properties, high drug loading and prolonged metformin hydrochloride release. It was shown that designed microparticles reduced rat glucose blood level, delayed absorption of metformin hydrochloride and provided stable plasma drug concentration. Additionally, histopathological studies of pancreas, liver and kidneys indicated that all prepared microparticles improved degenerative changes in organs of diabetic rats. Moreover, no toxicity effect and no changes in rats behavior after oral administration of chitosan cross-linked alginate microparticles were noted.

Fabrication, characterization and antimicrobial activities of thymol-loaded zein nanoparticles stabilized by sodium caseinate-chitosan hydrochloride double layers.

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Zhang, Yaqiong; Niu, Yuge; Luo, Yangchao; Ge, Mei; Yang, Tian; Yu, Liangli Lucy; Wang, Qin

2014-01-01

Thymol-loaded zein nanoparticles stabilized with sodium caseinate (SC) and chitosan hydrochloride (CHC) were prepared and characterized. The SC stabilized nanoparticles had well-defined size range and negatively charged surface. Due to the presence of SC, the stabilized zein nanoparticles showed a shift of isoelectric point from 6.18 to 5.05, and had a desirable redispersibility in water at neutral pH after lyophilization. Coating with CHC onto the SC stabilized zein nanoparticles resulted in increased particle size, reversal of zeta potential value from negative to positive, and improved encapsulation efficiency. Both thymol-loaded zein nanoparticles and SC stabilized zein nanoparticles had a spherical shape and smooth surface, while the surfaces of CHC-SC stabilized zein nanoparticles seemed rough and had some clumps. Encapsulated thymol was more effective in suppressing gram-positive bacterium than un-encapsulated thymol for a longer time period. Copyright © 2013 Elsevier Ltd. All rights reserved.

Antibacterial action mode of quaternized carboxymethyl chitosan/poly(amidoamine) dendrimer core–shell nanoparticles against Escherichia coli correlated with molecular chain conformation

Energy Technology Data Exchange (ETDEWEB)

Wen, Yan [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); School of Science, Tianjin University of Commerce, Tianjin 300134 (China); Yao, Fanglian, E-mail: yaofanglian@tju.edu.cn [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Sun, Fang [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Tan, Zhilei [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300222 (China); Tian, Liang [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Xie, Lei; Song, Qingchao [College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300222 (China)

2015-03-01

The action mode of quaternized carboxymethyl chitosan/poly(amidoamine) dendrimer core–shell nanoparticles (CM-HTCC/PAMAM) against Escherichia coli (E. coli) was investigated via a combination of approaches including measurements of cell membrane integrity, outer membrane (OM) and inner membrane (IM) permeability, and scanning electron microscopy (SEM). CM-HTCC/PAMAM dendrimer nanoparticles likely acted in a sequent event-driven mechanism, beginning with the binding of positively charged groups from nanoparticle surface with negative cell surface, thereby causing the disorganization of cell membrane, and subsequent leakage of intracellular components which might ultimately lead to cell death. Moreover, the chain conformation of polymers was taken into account for a better understanding of the antibacterial action mode by means of viscosity and GPC measurements. High utilization ratio of positive charge and large specific surface area generated from a compacted conformation of CM-HTCC/PAMAM, significantly different from the extended conformation of HTCC, were proposed to be involved in the antibacterial action. - Highlights: • The nanoparticles exerted antibacterial activity in a sequent event-driven manner. • Electrostatic interaction and surface adsorption shared roles in antibacterial mode. • The two factors were controlled by the compacted conformation of nanoparticles.

Antibacterial action mode of quaternized carboxymethyl chitosan/poly(amidoamine) dendrimer core–shell nanoparticles against Escherichia coli correlated with molecular chain conformation

International Nuclear Information System (INIS)

Wen, Yan; Yao, Fanglian; Sun, Fang; Tan, Zhilei; Tian, Liang; Xie, Lei; Song, Qingchao

2015-01-01

The action mode of quaternized carboxymethyl chitosan/poly(amidoamine) dendrimer core–shell nanoparticles (CM-HTCC/PAMAM) against Escherichia coli (E. coli) was investigated via a combination of approaches including measurements of cell membrane integrity, outer membrane (OM) and inner membrane (IM) permeability, and scanning electron microscopy (SEM). CM-HTCC/PAMAM dendrimer nanoparticles likely acted in a sequent event-driven mechanism, beginning with the binding of positively charged groups from nanoparticle surface with negative cell surface, thereby causing the disorganization of cell membrane, and subsequent leakage of intracellular components which might ultimately lead to cell death. Moreover, the chain conformation of polymers was taken into account for a better understanding of the antibacterial action mode by means of viscosity and GPC measurements. High utilization ratio of positive charge and large specific surface area generated from a compacted conformation of CM-HTCC/PAMAM, significantly different from the extended conformation of HTCC, were proposed to be involved in the antibacterial action. - Highlights: • The nanoparticles exerted antibacterial activity in a sequent event-driven manner. • Electrostatic interaction and surface adsorption shared roles in antibacterial mode. • The two factors were controlled by the compacted conformation of nanoparticles

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

African Journals Online (AJOL)

Methods: Chitosan acetate was chemically modified with acetaldehyde and the solution was prepared with 1 % acetic acid, in which was dissolved propranolol hydrochloride, was cast as films in Petri dish and characterised by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and ...

Carboxymethyl chitosan/conducting polymer as water-soluble composite binder for LiFePO4 cathode in lithium ion batteries

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Zhong, Haoxiang; He, Aiqin; Lu, Jidian; Sun, Minghao; He, Jiarong; Zhang, Lingzhi

2016-12-01

A water-soluble conductive composite binder consisting of carboxymethyl chitosan (CCTS) as a binder and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as a conduction-promoting agent is reported for the LiFePO4 (LFP) cathode in Li-ion batteries. The introduction of conductive PEDOT:PSS as a conductive composite binder facilitates the formation of homogeneous and continuous conducting bridges throughout the electrode and raises the compaction density of the electrode sheet by decreasing the amounts of the commonly used conducting agent of acetylene black. The optimized replacement ratios of acetylene black with PEDOT:PSS (acetylene black/PEDOT:PSS = 1:1, by weight) are obtained by measuring electrical conductivity, peel strength and compaction density of the electrode sheets. The LFP half-cell with the optimized conductive binder exhibits better cycling and rate performance and more favorable electrochemical kinetics than that using only acetylene black conducting agent. The pilot application of PEDOT:PSS/CCTS binder in 10 Ah CCTS-LFP prismatic cell exhibits a comparable cycling performance, retaining 89.7% of capacity at 1 C/2 C (charge/discharge) rate as compared with 90% for commercial PVDF-LFP over 1000 cycles, and better rate capability than that of commercial PVDF-LFP, retaining 98% capacity of 1 C at 7 C rate as compared with 95.4% for PVDF-LFP.

Development of chitosan-pullulan composite nanoparticles for nasal delivery of vaccines: in vivo studies.

Science.gov (United States)

Cevher, Erdal; Salomon, Stefan K; Somavarapu, Satyanarayana; Brocchini, Steve; Alpar, H Oya

2015-01-01

Here, we aimed at developing chitosan/pullulan composite nanoparticles and testing their potential as novel systems for the nasal delivery of diphtheria toxoid (DT). All the chitosan derivatives [N-trimethyl (TMC), chloride and glutamate] and carboxymethyl pullulan (CMP) were synthesised and antigen-loaded composites were prepared by polyion complexation of chitosan and pullulan derivatives (particle size: 239-405 nm; surface charge: +18 and +27 mV). Their immunological effects after intranasal administration to mice were compared to intramuscular route. Composite nanoparticles induced higher levels of IgG responses than particles formed with chitosan derivative and antigen. Nasally administered TMC-pullulan composites showed higher DT serum IgG titre when compared with the other composites. Co-encapsulation of CpG ODN within TMC-CMP-DT nanoparticles resulted in a balanced Th1/Th2 response. TMC/pullulan composite nanoparticles also induced highest cytokine levels compared to those of chitosan salts. These findings demonstrated that TMC-CMP-DT composite nanoparticles are promising delivery system for nasal vaccination.

Ab initio computational study of –N-C and –O-C bonding formation : functional group modification reaction based chitosan

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Siahaan, P.; Salimah, S. N. M.; Sipangkar, M. J.; Hudiyanti, D.; Djunaidi, M. C.; Laksitorini, M. D.

2018-04-01

Chitosan application in pharmaceutics and cosmeceutics industries is limited by its solubility issue. Modification of -NH2 and -OH fuctional groups of chitosan by adding carboxyl group has been shown to improve its solubility and application. Attempt to synthesize carboxymethyl chitosan (CMC) from monocloroacetic acid (MCAA) has been done prior this report. However no information is available wether –OH (-O-C bonding formation) or -NH2 (-N-C bonding formation) is the preference for - CH2COOH to attach. In the current study, the reaction mechanism between chitosan and MCAA reactants into carboxymethyl chitosan (CMC) was examined by computational approach. Dimer from of chitosan used as a molecular model in calculation All the molecular structure involved in the reaction mechanism was optimized by ab initio computational on the theory and basis set HF/6-31G(d,p). The results showed that the - N-C bonding formation via SN2 than the -O-C bonding formation via SN2 which have activation energy 469.437 kJ/mol and 533.219 kJ/mol respectively. However, the -O-C bonding formation more spontaneous than the -N-C bonding formation because ΔG the formation of O-CMC-2 reaction is more negative than ΔG of formation N-CMC-2 reaction is -4.353 kJ/mol and -1.095 kJ/mol respectively. The synthesis of N,O-CMC first forms -O-CH2COOH, then continues to form -NH-CH2COOH. This information is valuable to further optimize the reaction codition for CMC synthesis.

Preparation of porous carboxymethyl chitosan grafted poly (acrylic acid) superabsorbent by solvent precipitation and its application as a hemostatic wound dressing

Energy Technology Data Exchange (ETDEWEB)

Chen, Yu, E-mail: cylsy@163.com [School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Zhang, Yong [School of Life Science, Beijing Institute of Technology, Beijing 100081 (China); Wang, Fengju [School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Meng, Weiwei; Yang, Xinlin [School of Life Science, Beijing Institute of Technology, Beijing 100081 (China); Li, Peng [School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Jiang, Jianxin [State Key Laboratory of Trauma Burns and Combined Injury, The Third Military Medical University, Chongqing 400042 (China); Tan, Huimin [School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Zheng, Yongfa [Guangdong Fuyang Biotechnology Co., Ltd., Heyuan, Guangdong 517000 (China)

2016-06-01

The volume phase transition of a hydrogel initiated by shrinking may result in complex patterns on its surface. Based on this unique property of hydrogel, we have developed a novel solvent precipitation method to prepare a kind of novel superabsorbent polymers with excellent hemostatic properties. A porous carboxymethyl chitosan grafted poly (acrylic acid) (CMCTS-g-PAA) superabsorbent polymer was prepared by precipitating CMCTS-g-PAA hydrogel with ethanol. Its potential application in hemostatic wound dressing was investigated. The results indicate that the modified superabsorbent polymer is non-cytotoxic. It showed a high swelling capacity and better hemostatic performance in the treatments of hemorrhage model of ear artery, arteria cruralis and spleen of the New Zealand white rabbit than the unmodified polymer and other commonly used clinic wound dressings. The hemostatic mechanism of the porous CMCTS-g-PAA polymer was also discussed. - Highlights: • The novel solvent precipitation method was developed to prepare the porous superabsorbent polymer. • The swelling rate was promoted and the harmful residual monomer was leached after modification. • The modified polymer showed good biological safety. • It showed good hemostasis to arterial hemorrhage model of the animal. • The hemostatic mechanism of the modified superabsorbent polymer was discussed.

Preparation and biological properties of a novel composite scaffold of nano-hydroxyapatite/chitosan/carboxymethyl cellulose for bone tissue engineering

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Chengdong Xiong

2009-07-01

Full Text Available Abstract In this study, we report the physico-chemical and biological properties of a novel biodegradable composite scaffold made of nano-hydroxyapatite and natural derived polymers of chitosan and carboxymethyl cellulose, namely, n-HA/CS/CMC, which was prepared by freeze-drying method. The physico-chemical properties of n-HA/CS/CMC scaffold were tested by infrared absorption spectra (IR, transmission electron microscope(TEM, scanning electron microscope(SEM, universal material testing machine and phosphate buffer solution (PBS soaking experiment. Besides, the biological properties were evaluated by MG63 cells and Mesenchymal stem cells (MSCs culture experiment in vitro and a short period implantation study in vivo. The results show that the composite scaffold is mainly formed through the ionic crossing-linking of the two polyions between CS and CMC, and n-HA is incorporated into the polyelectrolyte matrix of CS-CMC without agglomeration, which endows the scaffold with good physico-chemical properties such as highly interconnected porous structure, high compressive strength and good structural stability and degradation. More important, the results of cells attached, proliferated on the scaffold indicate that the scaffold is non-toxic and has good cell biocompatibility, and the results of implantation experiment in vivo further confirm that the scaffold has good tissue biocompatibility. All the above results suggest that the novel degradable n-HA/CS/CMC composite scaffold has a great potential to be used as bone tissue engineering material.

Preparation and biological properties of a novel composite scaffold of nano-hydroxyapatite/chitosan/carboxymethyl cellulose for bone tissue engineering

Science.gov (United States)

Liuyun, Jiang; Yubao, Li; Chengdong, Xiong

2009-01-01

In this study, we report the physico-chemical and biological properties of a novel biodegradable composite scaffold made of nano-hydroxyapatite and natural derived polymers of chitosan and carboxymethyl cellulose, namely, n-HA/CS/CMC, which was prepared by freeze-drying method. The physico-chemical properties of n-HA/CS/CMC scaffold were tested by infrared absorption spectra (IR), transmission electron microscope(TEM), scanning electron microscope(SEM), universal material testing machine and phosphate buffer solution (PBS) soaking experiment. Besides, the biological properties were evaluated by MG63 cells and Mesenchymal stem cells (MSCs) culture experiment in vitro and a short period implantation study in vivo. The results show that the composite scaffold is mainly formed through the ionic crossing-linking of the two polyions between CS and CMC, and n-HA is incorporated into the polyelectrolyte matrix of CS-CMC without agglomeration, which endows the scaffold with good physico-chemical properties such as highly interconnected porous structure, high compressive strength and good structural stability and degradation. More important, the results of cells attached, proliferated on the scaffold indicate that the scaffold is non-toxic and has good cell biocompatibility, and the results of implantation experiment in vivo further confirm that the scaffold has good tissue biocompatibility. All the above results suggest that the novel degradable n-HA/CS/CMC composite scaffold has a great potential to be used as bone tissue engineering material. PMID:19594953

Nanosized complexation assemblies housed inside reverse micelles churn out monocytic delivery cores for bendamustine hydrochloride.

Science.gov (United States)

Singh, Yuvraj; Chandrashekhar, Anumandla; Meher, Jaya Gopal; Durga Rao Viswanadham, K K; Pawar, Vivek K; Raval, Kavit; Sharma, Komal; Singh, Pankaj K; Kumar, Animesh; Chourasia, Manish K

2017-04-01

We explore a plausible method of targeting bendamustine hydrochloride (BM) to circulatory monocytes by exploiting their intrinsic endocytic/phagocytic capability. We do so by complexation of sodium alginate and chitosan inside dioctyl sulfo succinate sodium (AOT) reverse micelles to form bendamustine hydrochloride loaded nanoparticles (CANPs). Dynamic light scattering, electrophoretic mobility and UV spectroscopy were used to detail intra-micellar complexation dynamics and to prove that drug was co-captured during interaction of carbohydrate polymers. A fluorescent conjugate of drug (RBM) was used to trace its intracellular fate after its loading into nanoparticles. CANPs were sized below 150nm, had 75% drug entrapment and negative zeta potential (-30mV). Confocal microscopy demonstrated that developed chitosan alginate nanoparticles had the unique capability to carry BM specifically to its site of action. Quantitative and mechanism based cell uptake studies revealed that monocytes had voracious capacity to internalize CANPs via simultaneous scavenger receptor based endocytic and phagocytic mechanism. Comparative in vitro pharmacokinetic studies revealed obtainment of significantly greater intracellular drug levels when cells were treated with CANPs. This caused reduction in IC 50 (22.5±2.1μg/mL), enhancement in G 2 M cell cycle arrest, greater intracellular reactive oxygen species generation, and increased apopotic potential of bendamustine hydrochloride in THP-1 cells. Selective monocytic targeting of bendamustine hydrochloride using carbohydrate constructs can prove advantageous in case of leukemic disorders displaying overabundance of such cells. Copyright © 2017 Elsevier B.V. All rights reserved.

Peritoneal adhesion prevention with a biodegradable and injectable N,O-carboxymethyl chitosan-aldehyde hyaluronic acid hydrogel in a rat repeated-injury model

Science.gov (United States)

Song, Linjiang; Li, Ling; He, Tao; Wang, Ning; Yang, Suleixin; Yang, Xi; Zeng, Yan; Zhang, Wenli; Yang, Li; Wu, Qinjie; Gong, Changyang

2016-11-01

Postoperative peritoneal adhesion is one of the serious issues because it induces severe clinical disorders. In this study, we prepared biodegradable and injectable hydrogel composed of N,O-carboxymethyl chitosan (NOCC) and aldehyde hyaluronic acid (AHA), and assessed its anti-adhesion effect in a rigorous and severe recurrent adhesion model which is closer to clinical conditions. The flexible hydrogel, which gelated in 66 seconds at 37 °C, was cross-linked by the schiff base derived from the amino groups of NOCC and aldehyde groups in AHA. In vitro cytotoxicity test showed the hydrogel was non-toxic. In vitro and in vivo degradation examinations demonstrated the biodegradable and biocompatibility properties of the hydrogel. The hydrogel discs could prevent the invasion of fibroblasts, whereas fibroblasts encapsulated in the porous 3-dimensional hydrogels could grow and proliferate well. Furthermore, the hydrogel was applied to evaluate the anti-adhesion efficacy in a more rigorous recurrent adhesion model. Compared with normal saline group and commercial hyaluronic acid (HA) hydrogel, the NOCC-AHA hydrogel exhibited significant reduction of peritoneal adhesion. Compared to control group, the blood and abdominal lavage level of tPA was increased in NOCC-AHA hydrogel group. These findings suggested that NOCC-AHA hydrogel had a great potential to serve as an anti-adhesion candidate.

Elucidation of release characteristics of highly soluble drug trimetazidine hydrochloride from chitosan-carrageenan matrix tablets.

Science.gov (United States)

Li, Liang; Wang, Linlin; Shao, Yang; Tian, Ye; Li, Conghao; Li, Ying; Mao, Shirui

2013-08-01

The aim of this study was to better understand the underlying drug release characteristics from matrix tablets based on the combination of chitosan (CS) and different types of carrageenans [kappa (κ)-CG, iota (ι)-CG, and lambda (λ)-CG]. Highly soluble trimetazidine hydrochloride (TH) was used as a model drug. First, characteristics of drug release from different formulations were investigated, and then in situ complexation capacity of CG with TH and CS was studied by differential scanning calorimetry and Fourier transform infrared spectroscopy. Erosion and swelling of matrix were also characterized to better understand the drug-release mechanisms. Effects of pH and ionic strength on drug release were also studied. It was found that not only ι-CG and λ-CG could reduce the burst release of TH by the effect of TH-CG interaction, CS-ι-CG- and CS-λ-CG-based polyelectrolyte film could further modify the controlled-release behavior, but not CS-κ-CG. High pH and high ionic strength resulted in faster drug release from CS-κ-CG- and CS-ι-CG-based matrix, but drug release from CS-λ-CG-based matrix was less sensitive to pH and ionic strength. In conclusion, CS-λ-CG-based matrix tablets are quite promising as controlled-release drug carrier based on multiple mechanisms. Copyright © 2013 Wiley Periodicals, Inc.

Carboxymethyl Carrageenan Based Biopolymer Electrolytes

International Nuclear Information System (INIS)

Mobarak, N.N.; Jumaah, F.N.; Ghani, M.A.; Abdullah, M.P.; Ahmad, A.

2015-01-01

Highlights: • The paper highlights the potential of carboxymethyl carrageenan based on iota and kappa to be utilized as host polymer. • The highest conductivity were achieved up to ∼10 −3 S cm −1 by carboxymethyl carrageenan without the addition of plasticizer. • The electrochemical stability windows of the films were electrochemically stable up to 3.0 V. - Abstract: A series of biodegradable carboxymethyl carrageenan based polymer electrolytes, which are carboxymethyl kappa carrageenan (sulphate per disaccharide) and carboxymethyl iota carrageenan (two sulphates per disaccharide), have been prepared by a solution casting technique with different ratios of lithium nitrate (LiNO 3 ) salts. Interestingly, the lithium ions tended to interact with the carbonyl group in the different modes of symmetry, as observed from reflection Fourier transform infrared (ATR-FTIR) spectroscopy analysis. In the carboxymethyl kappa carrageenan electrolytes, as the concentration of LiNO 3 increased, the asymmetric stretching peak of the carbonyl bond became dominant because it can be observed clearly with the shifting of the peak from 1592 to 1602 cm −1 due to the interaction between the lithium ion and the carbonyl group, while the broad O-H stretching peak became sharp and intense. However, for the carboxymethyl iota carrageenan, the asymmetry stretching mode of the carbonyl group shifted from 1567 to 1599 cm −1 , as the salt concentration increased. The shifting of the C-O-C peak also occurred in the iota-based electrolytes. However, the changes in the peak that represented SO 4 2− symmetric stretching were only detected when the ion pair formation was observed. It was proposed that the peak shifting was due to the presence of the lithium ion pathway, forming a dative bond between the lithium and oxygen in the carbonyl group. Accordingly, as more peak shifting was observed, the number of the ion pathways also increased. This hypothesis was supported by the impedance

Obtaining Thin-Films Based on Chitosan and Carboxymethylcellulose with Antibacterial Properties for Biomedical Devices

Science.gov (United States)

Kapanovna Ospanova, Aliya; Esimkhanovna Savdenbekova, Balzhan; Kozybaevna Iskakova, Mariam; Amirzhanovna Omarova, Roza; Nokeevich Zhartybaev, Rahmet; Zhanbolatovna Nussip, Balnur; Serikuly Abdikadyr, Aibek

2017-09-01

The physico-chemical studies of produsing nanocoating in the form of multilayers on the basis of chitosan and carboxymethyl cellulose were done. Was justified the use of triclosan, chlorhexidine, silver ions and iodine as potential antibacterial agents in the composition of nano-coating for medical and biological implantable systems. Preliminary studies of antibacterial activity of the resulting multilayers on silicon plate showed good activity against many bacteria.

PEGylated carboxymethyl chitosan/calcium phosphate hybrid anionic nanoparticles mediated hTERT siRNA delivery for anticancer therapy.

Science.gov (United States)

Xie, Ying; Qiao, Hongzhi; Su, Zhigui; Chen, Minglei; Ping, Qineng; Sun, Minjie

2014-09-01

Lack of safe and effective delivery vehicle is the main obstacle for siRNA mediated cancer therapy. In this study, we synthesized a pH-sensitive polymer of PEG grafted carboxymethyl chitosan (PEG-CMCS) and developed anionic-charged hybrid nanoparticles of PEG-CMCS and calcium phosphate (CaP) for siRNA delivery through a single-step self-assembly method in aqueous condition. The formed nanoparticles with charge of around -8.25 mv and average diameter of 102.1 nm exhibited efficient siRNA encapsulation and enhanced colloidal and serum stability. The test in vitro indicated that the nanoparticles entered into HepG2 cells by endocytosis, and achieved endosomal escape of siRNA effectively due to the pH-responsive disassembly of nanoparticles and dissolution of CaP in the endosome. Reporter gene silencing assay showed that luciferase siRNA delivered by the anionic nanoparticles could achieve gene silencing efficacy comparable to that of conventional Lipofectamine 2000. Additionally, dramatic hTERT knockdown mediated by the anionic nanoparticles transfection induced significant apoptosis of HepG2 cells in vitro. After intravenous injection in tumor-bearing BALB/c nude mice, the nanoparticles specifically accumulated into tumor regions by EPR effect, leading to efficient and specific gene silencing sequentially. Most importantly, the nanoparticles carrying hTERT siRNA inhibited tumor growth significantly via silencing hTERT expression and inducing cells apoptosis in HepG2 tumor xenograft. Moreover, comprehensive safety studies of the nanoparticles confirmed their superior safety both in vitro and in vivo. We concluded that the PEG-CMCS/CaP hybrid anionic nanoparticles possessed potential as a safe and effective siRNA delivery system for anticancer therapy. Copyright © 2014 Elsevier Ltd. All rights reserved.

Fabrication and characterization of carboxymethyl cellulose novel microparticles for bone tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Gaihre, Bipin [Department of Bioengineering, The University of Toledo, Toledo, OH 43614 (United States); Jayasuriya, Ambalangodage C., E-mail: a.jayasuriya@utoledo.edu [Department of Bioengineering, The University of Toledo, Toledo, OH 43614 (United States); Department of Orthopaedic Surgery, University of Toledo Medical Center, Toledo, OH 43614 (United States)

2016-12-01

In this study we developed carboxymethyl cellulose (CMC) microparticles through ionic crosslinking with the aqueous ion complex of zirconium (Zr) and further complexing with chitosan (CS) and determined the physio-chemical and biological properties of these novel microparticles. In order to assess the role of Zr, microparticles were prepared in 5% and 10% (w/v) zirconium tetrachloride solution. Scanning electron microscopy (SEM) with energy dispersive X-ray spectrometer (EDS) results showed that Zr was uniformly distributed on the surface of the microparticles as a result of which uniform groovy surface was obtained. We found that Zr enhances the surface roughness of the microparticles and stability studies showed that it also increases the stability of microparticles in phosphate buffered saline. The crosslinking of anionic CMC with cationic Zr and CS was confirmed by Fourier transform infrared spectroscopy (FTIR) results. The response of murine pre-osteoblasts (OB-6) when cultured with microparticles was investigated. Live/dead cell assay showed that microparticles did not induce any cytotoxic effects as cells were attaching and proliferating on the well plate as well as along the surface of microparticles. In addition, SEM images showed that microparticles support the attachment of cells and they appeared to be directly interacting with the surface of microparticle. Within 10 days of culture most of the top surface of microparticles was covered with a layer of cells indicating that they were proliferating well throughout the surface of microparticles. We observed that Zr enhances the cell attachment and proliferation as more cells were present on microparticles with 10% Zr. These promising results show the potential applications of CMC-Zr microparticles in bone tissue engineering. - Highlights: • Zirconium ions crosslinked carboxymethyl cellulose microparticles were fabricated. • The microparticles were further stabilized by complexation with chitosan. �

Fabrication and characterization of carboxymethyl cellulose novel microparticles for bone tissue engineering

International Nuclear Information System (INIS)

Gaihre, Bipin; Jayasuriya, Ambalangodage C.

2016-01-01

In this study we developed carboxymethyl cellulose (CMC) microparticles through ionic crosslinking with the aqueous ion complex of zirconium (Zr) and further complexing with chitosan (CS) and determined the physio-chemical and biological properties of these novel microparticles. In order to assess the role of Zr, microparticles were prepared in 5% and 10% (w/v) zirconium tetrachloride solution. Scanning electron microscopy (SEM) with energy dispersive X-ray spectrometer (EDS) results showed that Zr was uniformly distributed on the surface of the microparticles as a result of which uniform groovy surface was obtained. We found that Zr enhances the surface roughness of the microparticles and stability studies showed that it also increases the stability of microparticles in phosphate buffered saline. The crosslinking of anionic CMC with cationic Zr and CS was confirmed by Fourier transform infrared spectroscopy (FTIR) results. The response of murine pre-osteoblasts (OB-6) when cultured with microparticles was investigated. Live/dead cell assay showed that microparticles did not induce any cytotoxic effects as cells were attaching and proliferating on the well plate as well as along the surface of microparticles. In addition, SEM images showed that microparticles support the attachment of cells and they appeared to be directly interacting with the surface of microparticle. Within 10 days of culture most of the top surface of microparticles was covered with a layer of cells indicating that they were proliferating well throughout the surface of microparticles. We observed that Zr enhances the cell attachment and proliferation as more cells were present on microparticles with 10% Zr. These promising results show the potential applications of CMC-Zr microparticles in bone tissue engineering. - Highlights: • Zirconium ions crosslinked carboxymethyl cellulose microparticles were fabricated. • The microparticles were further stabilized by complexation with chitosan. �

Gold/Chitosan Nanocomposites with Specific Near Infrared Absorption for Photothermal Therapy Applications

Directory of Open Access Journals (Sweden)

Guandong Zhang

2012-01-01

Full Text Available Gold/chitosan nanocomposites were synthesized and evaluated as a therapeutic agent for the photothermal therapy. Gold nanoparticles (Au NPs with controllable optical absorption in the near infrared (NIR region were prepared by the reaction of chloroauric acid and sodium thiosulfate. To apply these particles to cancer therapy, the bare Au NPs were coated with chitosan (CS, O-carboxymethyl chitosan (CMCS, and a blend of CS and CMCS for utilizations in physiologic conditions. The surface properties, optical stability, and photothermal ablation efficiency on hepatocellular carcinoma cells (HepG2 and human dermal fibroblast cells (HDF demonstrate that these gold nanocomposites have great potential as a therapeutic agent in in vitro tests. The CS-coated nanocomposites show the highest efficiency for the photo-ablation on the HepG2 cells, and the CS and CMCS blended coated particles show the best discrimination between the cancer cell and normal cells. The well-controlled NIR absorption and the biocompatible surface of these nanocomposites allow low-power NIR laser activation and low-dosage particle injection for the cancer cell treatment.

A label-free fluorescence biosensor for highly sensitive detection of lectin based on carboxymethyl chitosan-quantum dots and gold nanoparticles.

Science.gov (United States)

Liu, Ziping; Liu, Hua; Wang, Lei; Su, Xingguang

2016-08-17

In this work, we report a novel label-free fluorescence "turn off-on" biosensor for lectin detection. The highly sensitive and selective sensing system is based on the integration of carboxymethyl chitosan (CM-CHIT), CuInS2 quantum dots (QDs) and Au nanoparticles (NPs). Firstly, CuInS2 QDs featuring carboxyl groups were directly synthesized via a hydrothermal synthesis method. Then, the carboxyl groups on the CuInS2 QDs surface were interacted with the amino groups (NH2), carboxyl groups (COOH) and hydroxyl groups (OH) within CM-CHIT polymeric chains via electrostatic interactions and hydrogen bonding to form CM-CHIT-QDs assemblies. Introduction of Au NPs could quench the fluorescence of CM-CHIT-QDs through electron and energy transfer. In the presence of lectin, lectin could bind exclusively with CM-CHIT-QDs by means of specific multivalent carbohydrate-protein interaction. Thus, the electron and energy transfer process between CM-CHIT-QDs and Au NPs was inhibited, and as a result, the fluorescence of CM-CHIT-QDs was effectively "turned on". Under the optimum conditions, there was a good linear relationship between the fluorescence intensity ratio I/I0 (I and I0 were the fluorescence intensity of CM-CHIT-QDs-Au NPs in the presence and absence of lectin, respectively) and lectin concentration in the range of 0.2-192.5 nmol L(-1), And the detection limit could be down to 0.08 nmol L(-1). Furthermore, the proposed biosensor was employed for the determination of lectin in fetal bovine serum samples with satisfactory results. Copyright © 2016 Elsevier B.V. All rights reserved.

Chitosan-carboxymethylcellulose based microcapsules formulation for controlled release of active ingredients from cosmeto textile

Science.gov (United States)

Roy, J. C.; Ferri, A.; Salaün, F.; Giraud, S.; Chen, G.; Jinping, G.

2017-10-01

Chitosan-based emulsions were prepared at pH from 4.0 to 6.0. The zeta potential and droplet size were monitored at different pH. Double emulsions (wateroil- water) were observed due to the stiff conformation of chitosan at pH 4.0. At pH 5.0, the emulsion droplets were the smallest (2.9 μm) of the experimental pH range. The emulsion droplets were well dispersed due to high surface charge of chitosan (for example, +50 mV at pH 5.5) in entire pH range. The emulsion was treated with carboxymethyl cellulose (CMC) for neutralizing the charged chitosan on the surface of emulsion droplets. Above 10×10-2 mg/ml of CMC, no change in zeta potential was observed indicating no more free chitosan existed after neutralization with CMC. The emulsion was then crosslinked with different amount of glutaraldehyde. Upon increasing the amount of glutaraldehyde, the amount of core content inside the microcapsule and encapsulation efficiency of shell materials decreased gradually. The Dynamic Scanning Calorimetry data confirmed no interaction between core and shell material in the microencapsulation process. The thermal degradation of the microcapsules was examined by thermogravimetric analysis and a gradual decrease in the degradation temperature upon increasing glutaraldehyde concentration was found. The tuning of CMC concentration can provide valuable information regarding stable emulsion and efficient microcapsule formulation via coacervation.

Optimization of biodegradable sponges as controlled release drug matrices. I. Effect of moisture level on chitosan sponge mechanical properties.

Science.gov (United States)

Foda, Nagwa H; El-laithy, Hanan M; Tadros, Mina I

2004-04-01

Cross-linked chitosan sponges as controlled release drug carrier systems were developed. Tramadol hydrochloride, a centrally acting analgesic, was used as a model drug. The sponges were prepared by freeze-drying 1.25% and 2.5% (w/w) high and low M.wt. chitosan solutions, respectively, using glutaraldehyde as a cross-linking agent. The hardness of the prepared sponges was a function of glutaraldehyde concentration and volume where the optimum concentration that offered accepted sponge consistency was 5%. Below or above 5%, very soft or very hard and brittle sponges were obtained, respectively. The determined drug content in the prepared sponges was uniform and did not deviate markedly from the calculated amount. Scanning electron microscopy (SEM) was used to characterize the internal structures of the sponges. The SEM photos revealed that cross-linked high M.wt. chitosan sponges have larger size surface pores that form connections (channels) with the interior of the sponge than cross-linked low M.wt. ones. Moreover, crystals of the incorporated Tramadol hydrochloride were detected on the lamellae and within pores in both chitosan sponges. Differences in pore size and dissolution medium uptake capacity were crucial factors for the more delayed drug release from cross-linked low M.wt. chitosan sponges over high M.wt. ones at pH 7.4. Kinetic analysis of the release data using linear regression followed the Higuchi diffusion model over 12 hours. Setting storage conditions at room temperature under 80-92% relative humidity resulted in soft, elastic, and compressible sponges.

In vitro and in silico investigation of electrospun terbinafine hydrochloride-loaded buccal nanofibrous sheets.

Science.gov (United States)

Szabó, Péter; Daróczi, Tünde Beáta; Tóth, Gergő; Zelkó, Romána

2016-11-30

Terbinafine hydrochloride-loaded nanofibrous buccal films were formulated with the aim to improve the solubility and dissolution behavior; thus, the local effectiveness of the antifungal agent. Poly(vinyl alcohol) and chitosan polymer composites were selected as delivery base in order to enhance the mucoadhesion of the fibrous films. The dissolution of terbinafine hydrochloride was carried out applying a stainless steel disc assembly and the terbinafine concentration was determined by HPLC-MS in selective ion monitoring mode. The prediction of the absorption behavior of the prepared fibrous samples in the human oral cavity was modeled using GastroPlus™ software. The result indicates that the fibrous films enabled fast and complete dissolution of the active agent. The drug absorption from the oral cavity could be minimized by the employment of the proper oral transit model. Because of the limited absorption of terbinafine hydrochloride from the oral mucosa the formulation can be beneficial in local administration in the case of hold and expectorate administration mode. Copyright © 2016 Elsevier B.V. All rights reserved.

Patterns of the adsorption of bovine serum albumin on carboxymethyl dextran and carboxymethyl cellulose films

Science.gov (United States)

Paribok, I. V.; Solomyanskii, A. E.; Zhavnerko, G. K.

2016-02-01

Patterns of the adsorption of bovine serum albumin on carboxymethyl dextran and carboxymethyl cellulose films are studied by means of microcontact printing, atomic force microscopy, and quartz crystal microbalance. It is shown that both the charge of polysaccharide macromolecules and the technique for deposition of their films onto the surface (via adsorption from a solution or covalent cross-linking) are factors that determine the degree of nonspecific adsorption of the protein on such films.

Oxidized Xanthan Gum and Chitosan as Natural Adhesives for Cork

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Diana Paiva

2016-07-01

Full Text Available Natural cork stopper manufacturing produces a significant amount of cork waste, which is granulated and combined with synthetic glues for use in a wide range of applications. There is a high demand for using biosourced polymers in these composite materials. In this study, xanthan gum (XG and chitosan (CS were investigated as possible natural binders for cork. Xanthan gum was oxidized at two different aldehyde contents as a strategy to improve its water resistance. This modification was studied in detail by 1H and 13C nuclear magnetic resonance (NMR, and the degree of oxidation was determined by the hydroxylamine hydrochloride titration method. The performance of the adhesives was studied by tensile tests and total soluble matter (TSM determinations. Xanthan gum showed no water resistance, contrary to oxidized xanthan gum and chitosan. It is hypothesized that the good performance of oxidized xanthan gum is due to the reaction of aldehyde groups—formed in the oxidation process—with hydroxyl groups on the cork surface during the high temperature drying. Combining oxidized xanthan gum with chitosan did not yield significant improvements.

Design and construction of polymerized-chitosan coated Fe{sub 3}O{sub 4} magnetic nanoparticles and its application for hydrophobic drug delivery

Energy Technology Data Exchange (ETDEWEB)

Ding, Yongling [Key Laboratory for Liquid–solid Structural Evolution and Processing of Materials (Ministry of Education), Engineering Ceramics Key Laboratory of Shandong Province, Shandong University, Jinan 250061 (China); School of Materials Science and Engineering, University of Jinan, Jinan 250022 (China); Shen, Shirley Z. [Materials Science and Engineering, CSIRO, Highett Vic 3190 (Australia); Sun, Huadong [College of Chemical Engineering, China University of Petroleum, Qing Dao 266555 (China); Sun, Kangning, E-mail: sunkangning@sdu.edu.cn [Key Laboratory for Liquid–solid Structural Evolution and Processing of Materials (Ministry of Education), Engineering Ceramics Key Laboratory of Shandong Province, Shandong University, Jinan 250061 (China); School of Materials Science and Engineering, University of Jinan, Jinan 250022 (China); Liu, Futian, E-mail: mse_liuft@ujn.edu.cn [Key Laboratory for Liquid–solid Structural Evolution and Processing of Materials (Ministry of Education), Engineering Ceramics Key Laboratory of Shandong Province, Shandong University, Jinan 250061 (China); School of Materials Science and Engineering, University of Jinan, Jinan 250022 (China); Qi, Yushi; Yan, Jun [School of Materials Science and Engineering, University of Jinan, Jinan 250022 (China)

2015-03-01

In this study, a novel hydrogel, chitosan (CS) crosslinked carboxymethyl-β-cyclodextrin (CM-β-CD) polymer modified Fe{sub 3}O{sub 4} magnetic nanoparticles was synthesized for delivering hydrophobic anticancer drug 5-fluorouracil (CS-CDpoly-MNPs). Carboxymethyl-β-cyclodextrin being grafted on the Fe{sub 3}O{sub 4} nanoparticles (CDpoly-MNPs) contributed to an enhancement of adsorption capacities because of the inclusion abilities of its hydrophobic cavity with insoluble anticancer drugs through host–guest interactions. Experimental results indicated that the amounts of crosslinking agent and bonding times played a crucial role in determining morphology features of the hybrid nanocarriers. The nanocarriers exhibited a high loading efficiency (44.7 ± 1.8%) with a high saturation magnetization of 43.8 emu/g. UV–Vis spectroscopy results showed that anticancer drug 5-fluorouracil (5-Fu) could be successfully included into the cavities of the covalently linked CDpoly-MNPs. Moreover, the free carboxymethyl groups could enhance the bonding interactions between the covalently linked CDpoly-MNPs and anticancer drugs. In vitro release studies revealed that the release behaviors of CS-CDpoly-MNPs carriers were pH dependent and demonstrated a swelling and diffusion controlled release. A lower pH value led to swelling effect and electrostatic repulsion contributing to the protonation amine impact of NH{sub 3}{sup +}, and thus resulted in a higher release rate of 5-Fu. The mechanism of 5-Fu encapsulated into the magnetic chitosan nanoparticles was tentatively proposed. - Graphical abstract: A novel nanocarrier, chitosan-coated magnetic drug carrier nanoparticle (CS-CDpoly-MNPs) is fabricated for the delivery of insoluble anticancer drug by grafting CM-β-CD onto the magnetite surface. The grafting of CM-dextrins onto the surface of Fe{sub 3}O{sub 4} nanocrystal clusters can markedly increase the loading capacity of 5-Fu by virtue of CM-dextrins/5-Fu inclusion complex

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

Science.gov (United States)

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

2014-02-01

One important complication of diabetes mellitus is chronic, non-healing diabetic foot ulcers (DFUs). This study aims to develop and use dressings based on chitosan derivatives for the sustained delivery of neurotensin (NT), a neuropeptide that acts as an inflammatory modulator in wound healing. Three different derivatives, namely N-carboxymethyl chitosan, 5-methyl pyrrolidinone chitosan (MPC) and N-succinyl chitosan, are presented as potential biomaterials for wound healing applications. Our results show that MPC has the best fluid handling capacity and delivery profile, also being non-toxic to Raw 264.7 and HaCaT cells. NT-loaded and non-loaded MPC dressings were applied to control/diabetic wounds to evaluate their in vitro/in vivo performance. The results show that the former induced more rapid healing (50% wound area reduction) in the early phases of wound healing in diabetic mice. A NT-loaded MPC foam also reduced expression of the inflammatory cytokine TNF-α (Pdiabetic skin (P<0.001), significantly increasing fibroblast migration and collagen (COL1A1, COL1A2 and COL3A1) expression and deposition. These results suggest that MPC-based dressings may work as an effective support for sustained NT release to reduce DFUs. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Rheological properties of concentrated solutions of carboxymethyl starch

Directory of Open Access Journals (Sweden)

Stojanović Željko

2003-01-01

Full Text Available Carboxymethyl starch was synthesized by the esterification of starch with monochloroacetic acid in ethanol as a reaction medium. Three samples of carboxymethyl starch having different degrees of substitution were prepared. The influence of temperature on the viscosity of concentrated carboxymethyl starch solutions, as well as the dynamic-mechanical properties of the concentrated solutions were investigated. The activation energy of viscous flow was determined and it was found that it decreased with increasing degree of substitution. The results of the dynamic-mechanical measurements showed that solutions of starch and carboxymethyl starches with higher degrees of substitution behave as gels. Values of the storage modulus in the rubbery plateau were used to calculate the molar masses between two points of physical crosslinking, the density of crosslinking and the distance between two points of crosslinking.

Carboxymethyl inulin

NARCIS (Netherlands)

Van Brussel, D.L.; Batelaan, J.G,; Peters, A.; Van Bekkum, H.

1995-01-01

Abstract of corresponding document: US 5777090 (A) PCT No. PCT/EP94/04097 Sec. 371 Date Jun. 6, 1996 Sec. 102(e) Date Jun. 6, 1996 PCT Filed Dec. 9, 1994 PCT Pub. No. WO95/15984 PCT Pub. Date Jun. 15, 1995Disclosed is carboxymethyl inulin having a degree of substitution (DS) ranging from 0,15 to

PVA/CM-chitosan/honey hydrogels prepared by using the combined technique of irradiation followed by freeze-thawing

Science.gov (United States)

Afshari, M. J.; Sheikh, N.; Afarideh, H.

2015-08-01

Hydrogels with three components, poly(vinyl alcohol) (PVA), carboxymethylate chitosan (CM-chitosan) and honey have been prepared by using radiation method and radiation followed by freeze-thawing cycles technique (combinational method). The solid concentration of the polymer solution is 15 wt% and the ratios of PVA/CM-chitosan/honey are 10/1.5/3.5, 10/2/3, 10/3/2, and 10/3.5/1.5. The applied irradiation doses are 25, 30 and 40 kGy. Various tests have been done to evaluate the hydrogel properties to produce materials to be used as wound dressing. The results show that combinational method improves the mechanical strength of hydrogels while it has no significant effect on the water evaporation rate of gels. The combinational method decreases the swelling of hydrogels significantly, albeit this parameter is still acceptable for wound dressing. Microbiological analyses show that the hydrogel prepared by both methods can protect the wound from Escherichia coli bacterial infection. The wound healing test shows the good performance of the gels in mice.

Low molecular mass chitosan as carrier for hydrodynamically balanced system for sustained delivery of ciprofloxacin hydrochloride

OpenAIRE

VERMA, ANURAG; BANSAL, ASHOK K.; GHOSH, AMITAVA; PANDIT, JAYANTA K.

2012-01-01

Chitosan has become a focus of major interest in recent years due to its excellent biocompatibility, biodegradability and non-toxicity. Although this material has already been extensively investigated in the design of different types of drug delivery systems, it is still little explored for stomach specific drug delivery systems. The objective of the present investigation was to explore the potential of low molecular mass chitosan (LMCH) as carrier for a hydrodynamically balanced system (HBS)...

Effects of AMF- and PGPR-root inoculation and a foliar chitosan spray in single and combined treatments on powdery mildew disease in strawberry

Directory of Open Access Journals (Sweden)

Aiofe Lowe

2012-03-01

Full Text Available Trials were carried out using, as a root inoculants, mixed Glomus spp. (G. mossae, G. caledonium, and G. fasiculatum and Bacillus subtilis FZB24, and the plant activator N, O-carboxymethyl chitosan applied as a foliar spray. The treatments were applied singly and in combinations, on strawberry plants grown out of season in a greenhouse.  Both fruit yield and runner production were reduced due to disease.  Several of the treatments were found to have significant effects, increasing fruit number and yield, and runner production.  Disease symptom severity was lowest in the B. subtilis FZB24 plus chitosan treatment. The treatments giving significantly higher fruit yield/number and runner production werea inoculation with B. subtilis FZB24, and with B. subtilis FZB24 or AMF combined with chitosan spray. These treatments and a fungicide treatment, gave the same level of disease control.

Composite polymer electrolytes based on MG49 and carboxymethyl cellulose from kenaf

International Nuclear Information System (INIS)

Jafirin, Serawati; Ahmad, Ishak; Ahmad, Azizan

2013-01-01

The development of 49% poly(methyl methacrylate)-grafted natural rubber (MG49) and carboxymethyl cellulose as a composite polymer electrolyte film incorporating LiCF 3 SO 3 were explored. Carboxymethyl cellulose was synthesized from kenaf bast fibres via carboxymethylation process by alkali catalyzed reaction of cellulose with sodium chloroacetate. Reflection fourier transform infrared (ATR-FTIR) spectroscopy showed the presence of carboxyl peak after modification of cellulose with sodium chloroacetate. X-ray diffraction (XRD) analysis revealed that the crystallinity of cellulose was decrease after synthesis. High performance composite polymer electrolytes were prepared with various composition of carboxymethyl cellulose (2–10 wt%) via solution-casting method. The conductivity was increased with carboxymethyl cellulose loading. The highest conductivity value achieved was 3.3 × 10 −7 Scm −1 upon addition of 6% wt carboxymethyl cellulose. 6% wt carboxymethyl cellulose composition showed the highest tensile strength value of 7.9 MPa and 273 MPa of modulus value which demonstrated high mechanical performance with accepatable level of ionic conductivity

Composite polymer electrolytes based on MG49 and carboxymethyl cellulose from kenaf

Science.gov (United States)

Jafirin, Serawati; Ahmad, Ishak; Ahmad, Azizan

2013-11-01

The development of 49% poly(methyl methacrylate)-grafted natural rubber (MG49) and carboxymethyl cellulose as a composite polymer electrolyte film incorporating LiCF3SO3 were explored. Carboxymethyl cellulose was synthesized from kenaf bast fibres via carboxymethylation process by alkali catalyzed reaction of cellulose with sodium chloroacetate. Reflection fourier transform infrared (ATR-FTIR) spectroscopy showed the presence of carboxyl peak after modification of cellulose with sodium chloroacetate. X-ray diffraction (XRD) analysis revealed that the crystallinity of cellulose was decrease after synthesis. High performance composite polymer electrolytes were prepared with various composition of carboxymethyl cellulose (2-10 wt%) via solution-casting method. The conductivity was increased with carboxymethyl cellulose loading. The highest conductivity value achieved was 3.3 × 10-7 Scm-1 upon addition of 6% wt carboxymethyl cellulose. 6% wt carboxymethyl cellulose composition showed the highest tensile strength value of 7.9 MPa and 273 MPa of modulus value which demonstrated high mechanical performance with accepatable level of ionic conductivity.

Multi-step carboxymethylation of kappa-Carrageenan

International Nuclear Information System (INIS)

Aranilla, Charito Tranquilan; Nagasawa, Naotsugu; Bayquen, Aristea V.

2008-01-01

Many polysaccharide derivatives have been prepared by carboxymethylation reactions in order to increase the range of potential applications of these natural polymers in the chemical, food, pharmaceutical and cosmetic industries. Carboxymethylation of kappa-carrageenan was attempted for the first time to synthesize derivatives with various degree of substitution. A multistep carboxymethylation was performed under heterogeneous reaction conditions, in isopropyl alcohol/water slurry medium, with aqueous sodium hydroxide solution for activation, and monochloroacetic acid for etherification. The derivatives obtained had average degree of substitutions from 1.20 to 1.92 as determined by potentiometric back-titration. Chemical and structural characterization were accomplished by Gel Permeation Chromatography, Elemental analysis, FT-IR Spectroscopy, 1 H N and 13 C NMR Spectroscopy. The relative reactivity of the hydroxyl groups in κ-carrageenan dimer unit proceeded in the order O-C2 G4S > O-C6 G4S >O-C2 AG at a ratio of 1:0.6:O.4. (author)

Composite polymer electrolytes based on MG49 and carboxymethyl cellulose from kenaf

Energy Technology Data Exchange (ETDEWEB)

Jafirin, Serawati; Ahmad, Ishak; Ahmad, Azizan [Polymer Research Centre (PORCE), School of Chemical Science and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor Darul Ehsan (Malaysia)

2013-11-27

The development of 49% poly(methyl methacrylate)-grafted natural rubber (MG49) and carboxymethyl cellulose as a composite polymer electrolyte film incorporating LiCF{sub 3}SO{sub 3} were explored. Carboxymethyl cellulose was synthesized from kenaf bast fibres via carboxymethylation process by alkali catalyzed reaction of cellulose with sodium chloroacetate. Reflection fourier transform infrared (ATR-FTIR) spectroscopy showed the presence of carboxyl peak after modification of cellulose with sodium chloroacetate. X-ray diffraction (XRD) analysis revealed that the crystallinity of cellulose was decrease after synthesis. High performance composite polymer electrolytes were prepared with various composition of carboxymethyl cellulose (2–10 wt%) via solution-casting method. The conductivity was increased with carboxymethyl cellulose loading. The highest conductivity value achieved was 3.3 × 10{sup −7} Scm{sup −1} upon addition of 6% wt carboxymethyl cellulose. 6% wt carboxymethyl cellulose composition showed the highest tensile strength value of 7.9 MPa and 273 MPa of modulus value which demonstrated high mechanical performance with accepatable level of ionic conductivity.

Preparation and adsorption behavior for metal ions and humic acid of chitosan derivatives crosslinked by irradiation

International Nuclear Information System (INIS)

Zhao Long; Wasikiewicz, J.M.; Mitomo, H.; Nagasawa, N.; Yoshii, F.

2007-01-01

This article deals with the determination of the adsorption properties of metal ions and humic acid in wa- ter on crosslinked chitosan derivatives (carboxymethylchitosan) which were formed using the irradiation technique without any additives. The solubility test of these crosslinked materials were investigated in acidic, alkaline media, distilled water, and certain organic solvents. Scanning electron microscopic (SEM) images showed that the crosslinked chitosan derivatives possessed a porous morphological structure. Charged characteristic analyses demonstrated typically pH-dependent properties of the crosslinked materials. The adsorption studies were carded out by the batch method at room temperature. Adsorption of heavy metal ions (such as Cu 2+ , Cd 2+ ) and humic acid onto crosslinked samples was found to be strongly pH-dependent. Adsorption kinetic studies indicated the rapid removal of metal ions, and humic acid from the aqueous solutions. Moreover, isothermal adsorption data revealed that Cu 2+ , Cd 2+ , and humic acid were removed by these crosslinked materials with high efficiency. Adsorption isothermal data were interpreted well by the Langmuir equation. These crosslinked carboxymethylated chitosan derivatives indicate favorable adsorption of metal ions and humic acid. (authors)

Terbinafine hydrochloride nanovesicular gel: In vitro characterization, ex vivo permeation and clinical investigation.

Science.gov (United States)

AbdelSamie, Sara M; Kamel, Amany O; Sammour, Omaima A; Ibrahim, Shady M

2016-06-10

In this work, nanovesicular chitosan gels were prepared for dermal delivery of terbinafine hydrochloride (TBN HCl). Ethosomes and vesicles containing different types of penetration enhancers (PEs) viz. Terpenes (cineole and limonene), labrasol and transcutol were developed. The prepared vesicles were evaluated for physical characteristics as well as skin interaction. The selected vesicles were incorporated into chitosan gel. An in vivo animal study was done on rat induced superficial Candida infection model. Moreover, randomized double blind clinical study was done on patients to compare the effect of the selected nanovesicular gel against the market product. Results showed the formation of nearly spherical, mostly deformable vesicular systems with size range of 95.5-530nm, zeta potential range of -0.1 to 15mV and entrapment efficiency range of 20-96.7%. Penetration enhancer vesicles (PEVs) prepared with 4% limonene (ELI4) showed the highest percent of drug deposition in the skin (53%) and the highest local accumulation efficiency value (35.3). In vivo animal study showed that the lowest fungal burden produced with ELI4 chitosan gel. Clinical studies showed cure rate of 86% within 7days treatment in case of limonene nanovesicular gel compared to 20% for market product (Lamisil® cream). Copyright © 2016 Elsevier B.V. All rights reserved.

Role of chitosan on controlling the characteristics and antifungal activity of bioadhesive fluconazole vaginal tablets

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Rawan A. Fitaihi

2018-02-01

Full Text Available Vaginal fluconazole (FLZ prolonged release tablets containing chitosan in physical blends with other bioadhesive polymers were designed. Chitosan was mixed with hydroxypropyl methylcellulose (HPMC, guar gum or sodium carboxymethyl cellulose (NaCMC at different ratios and directly compressed into tablets. In-vitro release profiles of FLZ were monitored at pH 4.8. Compressing chitosan with HPMC at different ratios slowed FLZ release, however, time for 80% drug release (T80 did not exceed 4.3 h for the slowest formulation (F11. Adding of chitosan to guar gum at 1:2 ratio (F3 showed delayed release with T80 17.4 h while, in presence of PVP at 1:2:1 ratio (F5, T80 was 8.8 h. A blend of chitosan and NaCMC at 1:2 ratio (F15 showed prolonged drug release with T80 11.16 h. Formulations F5 and F15 showed fair physical characteristics for the powder and tablets and were subjected to further studies. Fast swelling was observed for F15 that reached 1160.53 ± 13.02% in 4 h with 2 h bioadhesion time to mouse peritoneum membrane compared with 458.83 ± 7.09% swelling with bioadhesion time exceeding 24 h for F5. Extensive swelling of F15 could indicate possible dehydration effect on vaginal mucosa. Meanwhile, antifungal activity against C. albicans was significantly high for F5.

The influence of stachydrine hydrochloride on the reperfusion model of mice with repetitive cerebral ischemia

Directory of Open Access Journals (Sweden)

Mingsan Miao

2017-03-01

Full Text Available To study the influence of stachydrine hydrochloride on the inflammatory cytokines and tissue morphology of the re-perfusion model of mice with repetitive cerebral ischemia and probe into the protection mechanism of stachydrine hydrochloride for cerebral ischemia reperfusion impairment. Build a repetitive cerebral ischemia reperfusion model by first blocking the common carotid artery on both sides for 10 min, then resuming perfusion for 10 min and then blocking the common carotid artery on both sides again for 10 min. Before the operation, all the mice in the Nimodipine group, and the big, medium and small stachydrine hydrochloride dose groups were given corresponding gastric perfusion, the mice in the sham operation group and the modeled groups were at the same time given 0.5% sodium carboxymethyl cellulose for gastric perfusion of the same volume. The medicine was fed daily for 7 consecutive days. The model was built 1 h after the last feed and the perfusion continued for 24 h after the operation. Then the death rate of the mice was calculated. The mouse brains were taken out to test the ICAM-1 level and the TNF-α level, and the serum was taken out to test the NSE level and the MPO level. The tissue morphology changes were also observed. All the repetitive cerebral ischemia reperfusion models were successfully duplicated. The stachydrine hydrochloride in all the dose groups significantly reduced the death rates of big and small mice, reduced the level of ICAM-1 and the level of TNF-α in the brain tissues and the NSE level and the MPO level in the serum, significantly alleviating the pathological impairment in the hippocampus. Stachydrine hydrochloride can significantly reduce the death rate of mice, improve the pathological changes in the hippocampus, inhibit inflammatory reactions after ischemia, thus reducing the re-perfusion impairment after cerebral ischemia.

Comblike poly(ethylene oxide)/hydrophobic C6 branched chitosan surfactant polymers as anti-infection surface modifying agents.

Science.gov (United States)

Mai-ngam, Katanchalee

2006-05-01

A series of structurally well-defined poly(ethylene oxide)/hydrophobic C6 branched chitosan surfactant polymers that undergo surface induced self assembly on hydrophobic biomaterial surfaces were synthesized and characterized. The surfactant polymers consist of low molecular weight (Mw) chitosan backbone with hydrophilic poly(ethylene oxide) (PEO) and hydrophobic hexyl pendant groups. Chitosan was depolymerized by nitrous acid deaminative cleavage. Hexanal and aldehyde-terminated PEO chains were simultaneously attached to low Mw chitosan hydrochloride via reductive amination. The surfactant polymers were prepared with various ratios of the two side chains. The molecular composition of the surfactant polymers was determined by FT-IR and 1H NMR. Surface active properties at the air-water interface were determined by Langmuir film balance measurements. The surfactant polymers with PEO/hexyl ratios of 1:3.0 and 1:14.4 were used as surface modifying agents to investigate their anti-infection properties. E. coli adhesion on Silastic surface was decreased significantly by the surfactant polymer with PEO/hexyl 1:3.0. Surface growth of adherent E. coli was effectively suppressed by both tested surfactant polymers.

Preparation and characterization of chitosan/genipin/poly(N-vinyl-2-pyrrolidone) films for controlled release drugs

Energy Technology Data Exchange (ETDEWEB)

Aldana, Ana Agustina, E-mail: aaldana@fcq.unc.edu.ar [Departamento de Quimica Organica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba (UNC), Edificio de Ciencias II, Medina Allende y Haya de la Torre, Ciudad Universitaria, Cordoba 5000 (Argentina); Gonzalez, Agustin, E-mail: agustingonzalez@fcq.unc.edu.ar [Departamento de Quimica Organica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba (UNC), Edificio de Ciencias II, Medina Allende y Haya de la Torre, Ciudad Universitaria, Cordoba 5000 (Argentina); Strumia, Miriam C., E-mail: mcs@fcq.unc.edu.ar [Departamento de Quimica Organica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba (UNC), Edificio de Ciencias II, Medina Allende y Haya de la Torre, Ciudad Universitaria, Cordoba 5000 (Argentina); Martinelli, Marisa, E-mail: mmartinelli@fcq.unc.edu.ar [Departamento de Quimica Organica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba (UNC), Edificio de Ciencias II, Medina Allende y Haya de la Torre, Ciudad Universitaria, Cordoba 5000 (Argentina)

2012-05-15

Highlights: Black-Right-Pointing-Pointer Cross-linked chitosan films using genipin and/or PVP. Black-Right-Pointing-Pointer Propranolol hydrochloride was used like a model drug to release studies. Black-Right-Pointing-Pointer Incorporating PVP improves mechanical and diffusion properties. Black-Right-Pointing-Pointer Ch-Gen 0.10% and Ch-Gen 0.10%-PVP have optimal behavior. - Abstract: The study of the physicochemical and functional properties of chitosan films cross-linked with genipin and poly(N-vinyl-2-pyrrolidone) (PVP) was performed in this work. Cross-linked films were prepared by casting method from acetic acid solutions. The structure and physical properties of the films were analyzed by infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy ({sup 13}C NMR), differential scanning calorimetry (DSC) and mechanical testings. Propranolol hydrochloride was used like a model drug to determine the behavior of drug release from films. The drug release capacity was measured and compared with the degree of cross-linking, mechanical properties and swelling index. There was an appropriate balance of hydrophilicity, mechanical properties and diffusion by the incorporation of PVP into the networks cross-linked with genipin. The combination of both cross-linkers allows obtaining a soft and tough material potentially applicable as a controlled release. This research represents the first report where both cross-linkers, chemical and ionic agents, are used for obtaining films. These studies suggest that the chitosan films prepared here are promising drug delivery systems for buccal application, with thermal stability and acceptable mechanical properties. Buccal films may be preferred in terms of flexibility and comfort.

Preparation and characterization of chitosan/genipin/poly(N-vinyl-2-pyrrolidone) films for controlled release drugs

International Nuclear Information System (INIS)

Aldana, Ana Agustina; González, Agustín; Strumia, Miriam C.; Martinelli, Marisa

2012-01-01

Highlights: ► Cross-linked chitosan films using genipin and/or PVP. ► Propranolol hydrochloride was used like a model drug to release studies. ► Incorporating PVP improves mechanical and diffusion properties. ► Ch–Gen 0.10% and Ch–Gen 0.10%–PVP have optimal behavior. - Abstract: The study of the physicochemical and functional properties of chitosan films cross-linked with genipin and poly(N-vinyl-2-pyrrolidone) (PVP) was performed in this work. Cross-linked films were prepared by casting method from acetic acid solutions. The structure and physical properties of the films were analyzed by infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy ( 13 C NMR), differential scanning calorimetry (DSC) and mechanical testings. Propranolol hydrochloride was used like a model drug to determine the behavior of drug release from films. The drug release capacity was measured and compared with the degree of cross-linking, mechanical properties and swelling index. There was an appropriate balance of hydrophilicity, mechanical properties and diffusion by the incorporation of PVP into the networks cross-linked with genipin. The combination of both cross-linkers allows obtaining a soft and tough material potentially applicable as a controlled release. This research represents the first report where both cross-linkers, chemical and ionic agents, are used for obtaining films. These studies suggest that the chitosan films prepared here are promising drug delivery systems for buccal application, with thermal stability and acceptable mechanical properties. Buccal films may be preferred in terms of flexibility and comfort.

Radiation synthesis of gelatin/CM-chitosan/{beta}-tricalcium phosphate composite scaffold for bone tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Zhou Ying [College of Engineering, Peking University, Beijing 100871 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Xu Ling, E-mail: lingxu@pku.edu.cn [College of Engineering, Peking University, Beijing 100871 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zhang Xiangmei; Zhao Yinghui [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Wei Shicheng, E-mail: sc-wei@pku.edu.cn [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Peking University, Beijing 100081 (China); Zhai Maolin [Beijing National Laboratory for Molecular Sciences, Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)

2012-05-01

A series of biodegradable composite scaffolds was fabricated from an aqueous solution of gelatin, carboxymethyl chitosan (CM-chitosan) and {beta}-tricalcium phosphate ({beta}-TCP) by radiation-induced crosslinking at ambient temperature. Ultrasonic treatment on the polymer solutions significantly influenced the distribution of {beta}-TCP particles. An ultrasonic time of 20 min, followed by 30 kGy irradiation induced a crosslinked scaffold with homogeneous distribution of {beta}-TCP particles, interconnected porous structure, sound swelling capacity and mechanical strength. Fourier Transform Infrared Spectroscopy and X-ray Diffraction analysis indicated that {beta}-TCP successfully incorporated with the network of gelatin and CM-chitosan. In vivo implantation of the scaffold into the mandible of beagle dog revealed that the scaffolds had excellent biocompatibility and the presence of {beta}-TCP can accelerate bone regeneration. The comprehensive results of this study paved way for the application of gelatin/CM-chitosan/{beta}-TCP composite scaffolds as candidate of bone tissue engineering material. - Highlights: Black-Right-Pointing-Pointer Radiation induced a crosslinked scaffold with interconnected porous structure. Black-Right-Pointing-Pointer Ultrasonic time of 20 min led to homogenerously distribution of {beta}-TCP. Black-Right-Pointing-Pointer Increasing amount of {beta}-TCP would restrict the swelling properties. Black-Right-Pointing-Pointer Proper fraction of {beta}-TCP will promote the mechanical properties of the scaffolds. Black-Right-Pointing-Pointer Hybrid of {beta}-TCP promoted the bone regeneration of the mandibles of beagle dogs.

Different chemical groups modification on the surface of chitosan nonwoven dressing and the hemostatic properties.

Science.gov (United States)

Yan, Dong; Hu, Shihao; Zhou, Zhongzheng; Zeenat, Shah; Cheng, Feng; Li, Yang; Feng, Chao; Cheng, Xiaojie; Chen, Xiguang

2018-02-01

The hemostatic properties of surface modified chitosan nonwoven had been investigated. The succinyl groups, carboxymethyl groups and quaternary ammonium groups were introduced into the surface of chitosan nonwoven (obtained NSCS, CMCS and TMCS nonwoven, respectively). For blood clotting, absorbance value (0.105±0.03) of NSCS1 nonwoven was the smallest (CS 0.307±0.002, NSCS2 0.148±0.002, CMCS1 0.195±0.02, CMCS2 0.233±0.001, TMCS1 0.191±0.002, TMCS2 0.345±0.002), which indicated the stronger hemostatic potential. For platelet aggregation, adenosine diphosphate agonist was added to induce the nonwoven to adhered platelets. The aggregation of platelet with TMCS2 nonwoven was highest (10.97±0.16%). Further research of blood coagulation mechanism was discussed, which indicated NSCS and CMCS nonwoven could activate the intrinsic pathway of coagulation to accelerate blood coagulation. NSCS1 nonwoven showed the shortest hemostatic time (147±3.7s) and the lowest blood loss (0.23±0.05g) in a rabbit ear artery injury model. These results demonstrated that these surface modified chitosan nonwoven dressings could use as a promising hemostatic intervention, especially NSCS nonwoven dressing. Copyright © 2017 Elsevier B.V. All rights reserved.

Multilayer sodium alginate beads with porous core containing chitosan based nanoparticles for oral delivery of anticancer drug.

Science.gov (United States)

Li, Jing; Jiang, Changqing; Lang, Xuqian; Kong, Ming; Cheng, Xiaojie; Liu, Ya; Feng, Chao; Chen, Xiguang

2016-04-01

To develop efficient and safe anticancer drug doxorubicin hydrochloride (DOX) delivery system for oral chemotherapy, chitosan based nanoparticles (CS/CMCS-NPs) composed of chitosan (CS) and o-carboxymeymethy chitosan (CMCS) were immobilized in multilayer sodium alginate beads (NPs-M-Beads). Two kinds of NPs-M-Beads, with or without porous core, were respectively prepared by internal or external ionic gelation method. In the small intestine, the intact CS/CMCS-NPs were able to escape from porous-beads and sustained release the loading DOX. In vivo results showed that the DOX could be efficiently absorbed by small intestine of SD rat and the higher concentration of the DOX in major organs of rats were found after oral administration of Porous-Beads, which were about 2-4 folds higher than that of non-porous-beads. These results suggested that the NPs-M-Beads with porous core to be exciting and promising for oral delivery of DOX. Copyright © 2015 Elsevier B.V. All rights reserved.

Carboxymethyl cellulase and cellobiase production by Clostridium acetobutylicum in an industrial fermentation medium.

OpenAIRE

Allcock, E R; Woods, D R

1981-01-01

The production of a carboxymethyl cellulase and a cellobiase by Clostridium acetobutylicum was demonstrated. In liquid medium the carboxymethyl cellulase was induced by molasses, and it was not repressed by glucose. Optimum carboxymethyl cellulase activity occurred at pH 4.6 and 37 degrees C.

21 CFR 522.2470 - Tiletamine hydrochloride and zolazepam hydrochloride for injection.

Science.gov (United States)

2010-04-01

... hydrochloride for injection. 522.2470 Section 522.2470 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT... injection. (a) Specifications. Tiletamine hydrochloride and zolazepam hydrochloride for injection when... pound of body weight. The maximum total safe dose is 13.6 milligrams per pound of body weight. (ii) In...

Design of amphoteric chitosan flocculants for phosphate and turbidity removal in wastewater.

Science.gov (United States)

Agbovi, Henry K; Wilson, Lee D

2018-06-01

An amphoteric flocculant (CMC-CTA) was synthesized by grafting 3-chloro-2-hydroxypropyl trimethylammonium chloride onto carboxymethyl chitosan (CMC). The turbidity and orthophosphate (P i ) removal properties of chitosan (CHI), CMC, and CMC-CTA were compared in the presence (and absence) of FeCl 3 coagulant. At a fixed FeCl 3 dosage, the effects of flocculant dosage, pH and settling time were evaluated. Turbidity removal (%) and optimal dosage (FeCl 3 ; mg/L) was determined: CMC-CTA (95.8%;5), CHI (88.8%;7.0) and CMC (68.8%;9.0). The corresponding P i removal (%) and dosage (mg/L) are listed: (93.4%;10), (90.6%;10), and (67.4%;5). Optimal turbidity and P i removal occurred at pH 4, where CMC-CTA had greater efficiency over CMC and CHI. The turbidity removal kinetics was described by the pseudo-second-order model, while P i removal followed the pseudo-first-order model. The removal process involves cooperative Coulombic interactions between the biopolymer/Fe(III)/P i and/or kaolinite colloids, along with polymer bridging effects. Copyright © 2018 Elsevier Ltd. All rights reserved.

Stability Indicating HPLC Method for Simultaneous Quantification of Trihexyphenidyl Hydrochloride, Trifluoperazine Hydrochloride and Chlorpromazine Hydrochloride from Tablet Formulation

Directory of Open Access Journals (Sweden)

P. Shetti

2010-01-01

Full Text Available A new, simple, precise, rapid, selective and stability indicating reversed-phase high performance liquid chromatographic (HPLC method has been developed and validated for simultaneous quantification of trihexyphenidyl hydrochloride, trifluoperazine hydrochloride and chlorpromazine hydrochloride from combined tablet formulation. The method is based on reverse-phase using C-18 (250×4.6 mm, 5 μm particle size column. The separation is achieved using isocratic elution by methanol and ammonium acetate buffer (1% w/v, pH 6.5 in the ratio of 85:15 v/v, pumped at flow rate 1.0 mL/min and UV detection at 215 nm. The column is maintained at 30 °C through out the analysis. This method gives baseline resolution. The total run time is 15 min. Stability indicating capability is established buy forced degradation experiment. The method is validated for specificity, accuracy, precision and linearity as per International conference of harmonisation (ICH. The method is accurate and linear for quantification of trihexyphenidyl hydrochloride, trifluoperazine hydrochloride and Chlorpromazine hydrochloride between 5 - 15 μg/mL, 12.5- 37.5 μg/mL and 62.5 - 187.5 μg/mL respectively.

Mussel-inspired chitosan-polyurethane coatings for improving the antifouling and antibacterial properties of polyethersulfone membranes.

Science.gov (United States)

Wang, Rui; Song, Xin; Xiang, Tao; Liu, Qiang; Su, Baihai; Zhao, Weifeng; Zhao, Changsheng

2017-07-15

A straightforward mussel-inspired approach was proposed to construct chitosan-polyurethane coatings and load Ag nanoparticles (AgNPs) to endow polyethersulfone (PES) membranes with dual-antibacterial and antifouling properties. The macromolecule O-carboxymethyl chitosan (CMC) was directly reacted with catechol in the absence of carbodiimide chemistry to form the coating and load AgNPs via in situ reduction; while lysine (Lys) was used as a representative small molecule for comparison. Then, PEG-based polyurethane (PU) was used for constructing Lys-Ag-PU and CMC-Ag-PU composite coatings, which substantially improved the protein antifouling property of the membranes. Furthermore, the CMC-Ag-PU coating exhibited superior broad-spectrum antibacterial property towards E. coli and S. aureus than Lys-Ag-PU coating. Meanwhile, the CMC-Ag-PU coating showed sustained antifouling property against bacteria and could reload AgNPs to be regenerated as antibacterial and antifouling coating. This approach is believed to have potential to fabricate reusable antifouling and antibacterial coatings on materials surfaces for aquatic industries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Prevenção de aderências pericárdicas pós-operatórias com uso de carboximetilquitosana termoestéril Prevention of postoperative pericardial adhesions using thermal sterile carboxymethyl chitosan

Directory of Open Access Journals (Sweden)

Luiz Renato Dias Daroz

2008-12-01

Full Text Available OBJETIVO: Este trabalho tem como objetivo avaliar alterações físico-químicas da carboximetilquitosana após termoesterilização e sua eficácia na prevenção de aderências pericárdicas pós-esternotomia. MÉTODOS: Após ser submetida a termoesterilização em autoclave, a carboximetilquitosana termoestéril (CMQte foi submetida a análises físico-químicas. Doze animais foram divididos em dois grupos e submetidos à pericardiotomia e a protocolo de indução de aderências. A seguir, foi aplicada de forma tópica a CMQte ou solução salina. Após 8 semanas, foi realizada esternotomia e avaliação macroscópica do grau de aderências, tempo de dissecção e quantidade do uso de dissecção cruenta e avaliação microscópica. RESULTADOS: As análises físico-químicas não mostraram diferença entre a CMQ e CMQte. A avaliação macroscópica mostrou que a intensidade das aderências foi significantemente menor no grupo CMQte (P=0,007. O tempo de dissecção e o uso de dissecção cruenta também apresentaram reduções significativas (P=0,007, P=0,008; respectivamente. CONCLUSÃO: O método de esterilização empregado não alterou as propriedades físico-químicas da carboximetilquitosana. O uso de biopolímeros de barreira como a CMQte pode reduzir a intensidade das aderências pós-cirúrgicas no pericárdio, diminuindo as complicações da esternotomia em reoperações cardiovasculares.OBJECTIVE: The aim of this study is to evaluate CMC physical-chemical alterations after thermal sterilization and its efficacy in preventing poststernotomy pericardial adhesions. METHODS: After autoclaving thermal sterilization, thermal sterile Carboxymethyl Chitosan (CMCts was submitted to physical-chemical analysis. Twelve animals were divided into two groups and underwent pericardiotomy and adhesion induction protocol. Afterward, topic CMCts or saline solution was administered. After 8 weeks, a sternotomy was performed for adhesion score

Cartap Hydrochloride Poisoning.

Science.gov (United States)

Kalyaniwala, Kimmin; Abhilash, Kpp; Victor, Peter John

2016-08-01

Cartap hydrochloride is a moderately hazardous nereistoxin insecticide that is increasingly used for deliberate self-harm in India. It can cause neuromuscular weakness resulting in respiratory failure. We report a patient with 4% Cartap hydrochloride poisoning who required mechanical ventilation for 36-hours. He recovered without any neurological deficits. We also review literature on Cartap hydrochloride poisoning. © Journal of the Association of Physicians of India 2011.

In situ green synthesis of antimicrobial carboxymethyl chitosan–nanosilver hybrids with controlled silver release

Science.gov (United States)

Huang, Siqi; Yu, Zhiming; Zhang, Yang; Qi, Chusheng; Zhang, Shifeng

2017-01-01

In order to fabricate antimicrobial carboxymethyl chitosan–nanosilver (CMC-Ag) hybrids with controlled silver release, this study demonstrated comparable formation via three synthetic protocols: 1) carboxymethyl chitosan (CMC) and glucose (adding glucose after AgNO3), 2) CMC and glucose (adding glucose before AgNO3), and 3) CMC only. Under principles of green chemistry, the synthesis was conducted in an aqueous medium exposed to microwave irradiation for 10 minutes with nontoxic chemicals. The structure and formation mechanisms of the three CMC-Ag hybrids were explored using X-ray diffraction, ultraviolet-visible spectroscopy, transmission electron microscopy, and Fourier-transform infrared analyses. Additionally, antimicrobial activity and in vitro silver release of the three synthesized hybrids were investigated in detail. The results revealed that a large number of stable, uniform, and small silver nanoparticles (AgNPs) were synthesized in situ on CMC chains via protocol 1. AgNPs were well dispersed with narrow size distribution in the range of 6–20 nm, with mean diameter only 12.22±2.57 nm. The addition of glucose resulted in greater AgNP synthesis. The order of addition of glucose and AgNO3 significantly affected particle size and size distribution of AgNPs. Compared to CMC alone and commercially available AgNPs, the antimicrobial activities of three hybrids were significantly improved. Of the three hybrids, CMC-Ag1 synthesized via protocol 1 exhibited better antimicrobial activity than CMC-Ag2 and CMC-Ag3, and showed more effective inhibition of Staphylococcus aureus than Escherichia coli. Due to strong coordination and electrostatic interactions between CMC and silver and good steric protection provided by CMC, CMC-Ag1 displayed stable and continuous silver release and better performance in retaining silver for prolonged periods than CMC-Ag2 and CMC-Ag3. PMID:28458539

Self-association of analgesics in aqueous solution: micellar properties of dextropropoxyphene hydrochloride and methadone hydrochloride.

Science.gov (United States)

Attwood, D; Tolley, J A

1980-08-01

The solution properties of several analgesics including dextropropoxyphene hydrochloride, methadone hydrochloride, dextromoramide acid tartrate and dipipanone hydrochloride have been examined using light scattering, conductivity, vapour pressure osmometry and surface tension techniques. A micellar pattern of association was established for dextropropoxyphene hydrochloride and methadone hydrochloride and critical micelle concentrations and aggregation numbers are reported. The hydrophobic contribution to the free energy of micellization of dextropropoxyphene was determined from measurement of the critical micelle concentration in the presence of added electrolyte.

Design, characterization and in vitro evaluation of a novel thiolated polymer: preactivated carboxymethyl cellulose.

Science.gov (United States)

Laffleur, Flavia; Bacher, Lukas; Netsomboon, Kesinee

2016-01-01

To design a novel preactived carboxymethyl cellulose derivative. First, carboxymethyl cellulose (CMC) was chemically modified by amide bond formation between primary amino group of cysteine (CYS) and carboxylic moiety of CMC mediated by carbodiimide. Second, obtained CMCCYS was preactivated with 2,2'-dithiodinicotinic acid. Designed CMC-S-S-MNA was characterized by FT-IR. Furthermore, cytotoxicity was conducted on Caco-2 cell line. Swelling behavior, erosion and release of novel CMC-S-S-MNA were performed compared with thiolated and unmodified cellulose, respectively. CMC-S-S-MNA showed no harmful effect on cells. CMC-S-S-MNA exhibited 2.13-fold higher stability in comparison to unmodified cellulose. Furthermore, preactivated carboxymethyl cellulose-cysteine revealed 1.9-fold controlled released compared with respective unmodified carboxymethyl cellulose. Novel preactivated carboxymethyl cellulose represents a versatile excipient for drug delivery.

Laccase-Based CLEAs: Chitosan as a Novel Cross-Linking Agent

Directory of Open Access Journals (Sweden)

Alexandre Arsenault

2011-01-01

Full Text Available Laccase from Coriolopsis Polyzona was insolubilized as cross-linked enzyme aggregates (CLEAs for the first time with chitosan as the cross-linking agent. Concentrations between 0.01 and 1.867 g/L of chitosan were used and between 0.05 and 600 mM of 1-ethyl-3-(3-dimethylaminopropylcarbodiimide hydrochloride. The laccase was precipitated using ammonium sulphate and cross-linked simultaneously. Specific activity and thermal stability of these biocatalysts were measured. Activities of up to 737 U/g were obtained when 2,2-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid (ABTS was used as a substrate. Moreover, the stability of these biocatalysts was improved with regards to thermal degradation compared to free laccase when exposed to denaturing conditions of high temperature and low pH. The CLEAs stability against chemical denaturants was also tested but no significant improvement was detected. The total amount of ABTS to be oxidized during thermal degradation by CLEAs and free laccase was calculated and the insolubilized enzymes were reported to oxidize more substrate than free laccase. The formation conditions were analyzed by response surface methodology in order to determine an optimal environment for the production of efficient laccase-based CLEAs using chitosan as the cross-linking agent. After 24 hours of formation at pH 3 and at 4°C without agitation, the CLEAs exhibit the best specific activity.

Glycol chitosan

DEFF Research Database (Denmark)

Danielsen, E Thomas; Danielsen, E Michael

2017-01-01

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

Hyaluronic acid modified chitosan nanoparticles for effective management of glaucoma: development, characterization, and evaluation.

Science.gov (United States)

Wadhwa, Sheetu; Paliwal, Rishi; Paliwal, Shivani R; Vyas, S P

2010-05-01

In clinical practices, solution of dorzolamide hydrochloride (DH) and timolol maléate (TM) is recommended for the treatment of glaucoma. However, low drug-contact time and poor ocular bioavailability of drugs due to drainage of solution, tear turnover and its dilution or lacrimation limits its uses. In addition, systemic absorption of TM may induce undesirable cardiovascular side effects. Chitosan (CS) is a polycationic biodegradable polymer which provides sustained and local delivery of drugs to the ocular sites. Hyaluronic acid (HA) also provides synergistic effect for mucoadhesion in association with chitosan. In the present study, hyaluronic acid modified chitosan nanoparticles (CS-HA-NPs) loaded with TM and DH were developed and characterized. The CS-HA-NPs were evaluated for size, shape, zeta potential, entrapment efficiency, and mucoadhesive strength. The in vitro release study was also performed in PBS pH 7.4. The ocular irritation potential of CS-HA-NPs was estimated using draize test on albino rabbits. A significant reduction in IOP level was obtained using CS-HA-NPs as compared to plain solution of drug and a comparable higher reduction in IOP level was observed as to CS-NPs. These results suggest that HA potentialy enhance the mucoadhesiveness and efficiency of CS-NPs and may be promising carrier for ocular drug delivery.

Carboxymethyl-cellulase from Erwina chrysanthemi. I. Production and regulation of extracellular carboxymethyl-cellulase

Energy Technology Data Exchange (ETDEWEB)

Boyer, M.H.; Chambost, J.P.; Magnan, M.; Cattaneo, J.

1984-01-01

Erwinia chrysanthemi strain 3665 growing aerobically in a mineral salts medium containing various carbon sources constitutively secreted low levels of carboxymethyl-cellulase activity. Increased production of this activity was triggered by conditions which reduced the growth rate. The results obtained with continuous culture suggested that this production was controlled by a mechanism similar to catabolite repression. However, other factors might be implicated in the regulation of cellulase production.

21 CFR 522.1222b - Ketamine hydrochloride with promazine hydrochloride and aminopentamide hydrogen sulfate injection.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ketamine hydrochloride with promazine... RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.1222b Ketamine.... Ketamine hydrochloride, (±),-2-(o-chlorophenyl)-2-(methylamino) cyclohexanone hydrochloride, with promazine...

Okara promoted acrylamide and carboxymethyl-lysine formation in bakery products.

Science.gov (United States)

Palermo, Mariantonella; Fiore, Alberto; Fogliano, Vincenzo

2012-10-10

Soybeans are widely used in bakery products because of their technological advantages and, recently, soybean-containing products have been marketed as functional foods thanks to several health benefits. Okara is a soybean-based ingredient obtained after elimination of the water-soluble component from ground soybeans. In this paper the effect of okara addition to bakery products on the formation of some potentially harmful Maillard reaction products was evaluated. Cookies obtained by replacing 15% of wheat flour with okara showed a visible browning increase and a more intense Maillard reaction development as shown by higher concentrations of 5-hydroxymethyl-2-furaldehyde (HMF) (+100%), acrylamide (+60%), and carboxymethyl-lysine (CML) (+400%) with respect to the control. This phenomenon could be related to the presence in okara of about 50% of insoluble dietary fiber: the fiber reduces water activity during cooking, thus promoting Maillard reaction. To confirm this hypothesis, cookies obtained by replacing 7% of wheat flour with three different types of dietary fiber (cellulose, chitosan, and pea fiber) were prepared: these experimental cookies showed higher Maillard reaction product concentration with respect to the control and, in particular, HMF and CML values were directly related to the fiber water-holding capacity (WHC). To extend the observation to the food market, a sampling of soybean-containing commercial bakery products was analyzed by comparing the concentrations of Maillard reaction products with those of similar bakery products without soy. Soybean-containing samples showed higher concentrations of acrylamide and CML than corresponding controls.

Dataset on the physical characterization of biopolymer coated magnetic nanoparticles

Directory of Open Access Journals (Sweden)

Shazia Bano

2016-12-01

Full Text Available The data presented in this article is related to the research article entitled “Paclitaxel loaded magnetic nanocomposites with folate modified chitosan/carboxymethyl surface; a vehicle for imaging and targeted drug delivery” (S. Bano, M. Afzal, M.M. Waraich, K. Alamgir, S. Nazir, 2016 [1]. It contains the absorbance spectra, band gap energies of pure nickel-ferrite nano cores (NFs, and calibration curve of Paclitaxel. Thermal stability analysis of pure NFs, chitosan (CS and carboxymethyl cellulose (CMC-conjugated NFs samples is also included in the data.

PVA/CM-chitosan/honey hydrogels prepared by using the combined technique of irradiation followed by freeze-thawing

International Nuclear Information System (INIS)

Afshari, M.J.; Sheikh, N.; Afarideh, H.

2015-01-01

Hydrogels with three components, poly(vinyl alcohol) (PVA), carboxymethylate chitosan (CM-chitosan) and honey have been prepared by using radiation method and radiation followed by freeze-thawing cycles technique (combinational method). The solid concentration of the polymer solution is 15 wt% and the ratios of PVA/CM-chitosan/honey are 10/1.5/3.5, 10/2/3, 10/3/2, and 10/3.5/1.5. The applied irradiation doses are 25, 30 and 40 kGy. Various tests have been done to evaluate the hydrogel properties to produce materials to be used as wound dressing. The results show that combinational method improves the mechanical strength of hydrogels while it has no significant effect on the water evaporation rate of gels. The combinational method decreases the swelling of hydrogels significantly, albeit this parameter is still acceptable for wound dressing. Microbiological analyses show that the hydrogel prepared by both methods can protect the wound from Escherichia coli bacterial infection. The wound healing test shows the good performance of the gels in mice. - Highlights: • Hydrogels prepared by the combination of irradiation and freeze-thawing methods. • Hydrogels with improved mechanical strength prepared by the combinational method. • The prepared hydrogels had acceptable transparency and degree of swelling. • The water evaporation rates of these hydrogels were pretty low. • Presences of honey in the formulation of gels led to a higher tissue regeneration

Comparison of chitosan nanoparticles and chitosan hydrogels for vaccine delivery

DEFF Research Database (Denmark)

Gordon, Sarah; Saupe, Anne; McBurney, Warren

2008-01-01

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

Chitosan and chemically modified chitosan beads for acid dyes sorption

Institute of Scientific and Technical Information of China (English)

AZLAN Kamari; WAN SAIME Wan Ngah; LAI KEN Liew

2009-01-01

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

Heavy Metal Removal by Chitosan and Chitosan Composite

International Nuclear Information System (INIS)

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

2005-01-01

Radiation grafting of diethyl aminoethyl methacrylate (DEAEMA) on chitosan to impart ion exchange properties and to be used for the separation of metal ions from waste water, was carried out. The effect of experimental conditions such as monomer concentration and the radiation dose on grafting were studied. On using chitosan, grafted chitosan and some chitosan composites in metal ion removal they show high up-take capacity for Cu 2+ and lower uptake capacities for the other divalent metal ions used (Zn and Co). Competitive study, performed with solutions containing mixture of metal salts, showed high selectivity for Cu 2+ than the other metal ion. Limited grafting of DEAEMA polymer -containing specific functional groups-onto the chitosan backbone improves the sorption performance

Development of Cy5.5-Labeled Hydrophobically Modified Glycol Chitosan Nanoparticles for Protein Delivery

Science.gov (United States)

Chin, Amanda

Therapeutic proteins are often highly susceptible to enzymatic degradation, thus restricting their in vivo stability. To overcome this limitation, delivery systems designed to promote uptake and reduce degradation kinetics have undergone a rapid shift from macro-scale systems to nanomaterial based carriers. Many of these nanomaterials, however, elicit immune responses and may have cytotoxic effects both in vitro and in vivo. The naturally derived polysaccharide chitosan has emerged as a promising biodegradable material and has been utilized for many biomedical applications; nevertheless, its function is often constrained by poor solubility. Glycol chitosan, a derivative of chitosan, can be hydrophobically modified to impart amphiphilic properties that enable the self-assembly into nanoparticles in aqueous media at neutral pH. This nanoparticle system has shown initial success as a therapeutic agent in several model cell culture systems, but little is known about its stability against enzymatic degradation. Therefore, the goal of this research was to investigate the resistance of hydrophobically modified glycol chitosan against enzyme-catalyzed degradation using an in vivo simulated system containing lysozyme. To synthesize the nanoparticles, hydrophobic cholanic acid was first covalently conjugated to glycol chitosan using of N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). Conjugates were purified by dialysis, lyophilized, and ultra-sonicated to form nanoparticles. Fourier transform infrared (FT-IR) spectroscopy confirmed the binding of 5beta-cholanic acid to the glycol chitosan. Particle size and stability over time were determined with dynamic light scattering (DLS), and particle morphology was evaluated by transmission electron microscopy (TEM). The average diameter of the nanoparticles was approximately 200 nm, which remained stable at 4°C for up to 10 days. Additionally, a near infrared fluorescent (NIRF) dye

Cytocompatibility of chitosan and collagen-chitosan scaffolds for tissue engineering

Directory of Open Access Journals (Sweden)

Ligia L. Fernandes

2011-01-01

Full Text Available In this work, chitosan and collagen-chitosan porous scaffolds were produced by the freeze drying method and characterized as potential skin substitutes. Their beneficial effects on soft tissues justify the choice of both collagen and chitosan. Samples were characterized using scanning electron microscope, Fourier Transform InfraRed Spectroscopy (FTIR and thermogravimetry (TG. The in vitro cytocompatibility of chitosan and collagen-chitosan scaffolds was evaluated with three different assays. Phenol and titanium powder were used as positive and negative controls, respectively. Scanning electron microscopy revealed the highly interconnected porous structure of the scaffolds. The addition of collagen to chitosan increased both pore diameter and porosity of the scaffolds. Results of FTIR and TG analysis indicate that the two polymers interact yielding a miscible blend with intermediate thermal degradation properties. The reduction of XTT ((2,3-bis[2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide and the uptake of Neutral Red (NR were not affected by the blend or by the chitosan scaffold extracts, but the blend and the titanium powder presented greater incorporation of Crystal Violet (CV than phenol and chitosan alone. In conclusion, collagen-chitosan scaffolds produced by freeze-drying methods were cytocompatible and presented mixed properties of each component with intermediate thermal degradation properties.

Preparation and characterization of a novel composite containing carboxymethyl cellulose used for bone repair

International Nuclear Information System (INIS)

Jiang Liuyun; Li Yubao; Zhang Li; Wang Xuejiang

2009-01-01

The composite biomaterial made from nano-hydroxyapatite(n-HA) and chitosan(CS) cross-linked with carboxymethyl cellulose(CMC) by a co-solution method has been studied. Fourier transform infrared absorption spectra (IR), X-ray diffraction (XRD), burn-out test, chemical analysis, transmission electron microscope(TEM) and universal material testing machine were used to test the properties of the composite. The experiment of SBF soaking for 8 weeks was used to investigate their degradation and bioactivity in vitro. The results show that the formation of composite is mainly contributed to the ionic cross-linking of CMC with CS, and n-HA particles in the form of nanometer grade short crystals are uniformly distributed in the organic network structure of polyelectrolyte complexes, which endows the composite with high compressive strength and good bioactivity. The compressive strength and degradation rate are concerned with the content of n-HA. It can be stated that the n-HA/CS/CMC composite whose weight ratio is 40/30/30 may be a potential candidate as one of novel bone repair materials because of its high compressive strength and acceptable degradation rate as well as good bioactivity, displaying a promising prospect of the clinical application of CMC-contained composite in the field of bone repair

Preparation and physiological activities of carboxymethylated derivative purified from corn bran

Science.gov (United States)

Zhu, Linghui; Fang, Miaoli; Ma, Jianjun; Mo, Qing

2017-06-01

Two water-soluble polysaccharides extracted from corn bran were chemically modified to obtain their carboxymethylated derivatives (C-CBP1, C-CBP2). Theresults of degree of substitution and FT-IR analysis showed the carboxymethylation of polysaccharides were successful. The average molecular weight (Mw) of C-CBP1 and C-CBP2 were 368 and 263kDa, respectively. The degree of substitution (DS) of C-CBP1 and C-CBP2 were determined to be 0.44 and 0.46. The results showed that derivatives were effective in antioxidant and bile acidbinding activityin a dose dependent way. And C-CBP2 had the higher activity for hydroxyl radical, superoxide anion scavenging activities and bile acid capacity, as lower molecular weight plays a critical role in antioxidant activities and bile acid capacity. The results suggest that the carboxymethylated derivatives are potential natural antioxidant and blood fat reduce agent that can be used as drugs or functional food ingredients.

Compound list: fluoxetine hydrochloride [Open TG-GATEs

Lifescience Database Archive (English)

Full Text Available fluoxetine hydrochloride FLX 00158 ftp://ftp.biosciencedbc.jp/archive/open-tggates/...LATEST/Human/in_vitro/fluoxetine_hydrochloride.Human.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/o...pen-tggates/LATEST/Rat/in_vivo/Liver/Single/fluoxetine_hydrochloride.Rat.in_vivo.Liver.Single.zip ftp://ftp....biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Liver/Repeat/fluoxetine_hydrochloride.Rat.in_vivo.Liver.Repeat.zip ...

Butriptyline Hydrochloride and Imipramine Hydrochloride in the ...

African Journals Online (AJOL)

used tricyclic antidepressants, imipramine hydrochloride, was undertaken in 28 patients suffering from non-psychotic depression in a doubleblind trial. Three criteria-side-effects, depression and anxiety-were observed at each visit. The scoring ...

Review of radiation processing of natural polymer

International Nuclear Information System (INIS)

Khairul Zaman

2007-01-01

In recent years, natural polymers are being investigated with renewed interest because of their abundant quantity and unique characteristics such as inherent biocompatibility, biodegradability and renewable. It is also known as green polymer. Natural polymers such as carrageen, alginate, chitin/chitosan and starch are traditionally used in food-based industry. But now, the applications of natural polymers are being sought in knowledge-driven areas such as healthcare, agro-technology and industry. Radiation degraded alginates, carrangeenan and chitosan as plant growth promoter and protector have been developed. Radiation degraded chitosan, carraneenan and starch have also been used together with synthetic polymers for hydrogel production to be used for wound dressing, skin moisturization and for biodegradable packaging films and foams. Radiation crosslinking of natural polymer derivatives such as carboxymethyl chitosan, carboxymethyl starch have been successfully developed in Japan and used for various applications such as removal of pollutants, removal of waters from liverstock excrete as well as for bedsores protection mat. (author)

A Trojan-Horse Peptide-Carboxymethyl-Cytidine Antibiotic from Bacillus amyloliquefaciens.

Science.gov (United States)

Serebryakova, Marina; Tsibulskaya, Darya; Mokina, Olga; Kulikovsky, Alexey; Nautiyal, Manesh; Van Aerschot, Arthur; Severinov, Konstantin; Dubiley, Svetlana

2016-12-07

Microcin C and related antibiotics are Trojan-horse peptide-adenylates. The peptide part is responsible for facilitated transport inside the sensitive cell, where it gets processed to release a toxic warhead-a nonhydrolyzable aspartyl-adenylate, which inhibits aspartyl-tRNA synthetase. Adenylation of peptide precursors is carried out by MccB THIF-type NAD/FAD adenylyltransferases. Here, we describe a novel microcin C-like compound from Bacillus amyloliquefaciens. The B. amyloliquefaciens MccB demonstrates an unprecedented ability to attach a terminal cytidine monophosphate to cognate precursor peptide in cellular and cell free systems. The cytosine moiety undergoes an additional modification-carboxymethylation-that is carried out by the C-terminal domain of MccB and the MccS enzyme that produces carboxy-SAM, which serves as a donor of the carboxymethyl group. We show that microcin C-like compounds carrying terminal cytosines are biologically active and target aspartyl-tRNA synthetase, and that the carboxymethyl group prevents resistance that can occur due to modification of the warhead. The results expand the repertoire of known enzymatic modifications of peptides that can be used to obtain new biological activities while avoiding or limiting bacterial resistance.

Utilization of cross-linked carboxymethyl κ-carrageenan as adsorbent for hexavalent chromium (Cr+6) ion

International Nuclear Information System (INIS)

Antonio, Princess Joyce R.; Punzalan, Mark Emile H.; Saturno, Rochelle Anne B.; Bayquen, Aristea V.

2009-01-01

The sorption behavior of cross-linked carboxymethyl κ-carrageenan as an alternative adsorbent for hexavalent chromium was studies. The κ-carrageenan had been carboxymethylated three times with 40% NaOH and monochloroacetic acid (MCA) in 80% isopropyl alcohol at 40 0 C. Carboxymethylated κ-carrageenan was crosslinked using Co 60 irradiation facility at PNRI. Batch experiments were conducted using prepared stock solution of Cr 6+ (70 ppm) under different sorption parameters at room temperature. These parameters include effects of pH, initial metal ion concentration, and contact time. Carboxymethylation and cross-linking was successfully achieved under optimum parameters. It was observed that cross-linked carboxymethyl κ-carrageenan best adsorbs chromium (VI) ion at pH 6, removing 41.59% of the metal ions present in the solution. Freundlich isotherm gave the highest correlation, R 2 , which is equal to 0.9880. This suggests the existence of mutilayer adsorption of the hexavalent chromium ions. Maximum adsorption was found to be at contact time of 2.5 hours and the concentration of the solution remains almost constant after 5 hours. The adsorption kinetics could be approximated favorably by the Lagergren pseudo-second-order kinetic model giving a correlation, R 2 , of 0.9985 and adsorption capacity, qmax, equal to 27.88 mg g +1 . (author)

Development and evaluation of controlled-release buccoadhesive verapamil hydrochloride tablets

Directory of Open Access Journals (Sweden)

Emami J.

2008-05-01

Full Text Available Background and purpose of the study: Verapamil hydrochloride is a calcium channel blocker which is used in the control of supraventricular arrhythmia, hypertension and myocardial infraction. There are considerable inter-individual variations in serum concencentration of verpamil due to variation in the extent of hepatic metabolism. In this study controlled-release buccoadhesive tablets of verapamil hydrochloride (VPH were prepared in order to achieve constant plasma concentrations, to improve the bioavailability by the avoidance of hepatic first-pass metabolism, and to prevent frequent administration. Materials and methods: Tablets containing fixed amount of VPH were prepared by direct compression method using polymers like carbomer (CP, hydroxypropylmethyl cellulose (HPMC and sodium carboxymethyl cellulose (NaCMC in various combination and ratios and evaluated for thickness, weight variation, hardness, drug content uniformity, swelling, mucoadhesive strength, drug release and possible interaction between ingredients. Results: All tablets were acceptable with regard to thickness, weight variation, hardness, and drug content. The maximum bioadhesive strength was observed in tablets formulated with a combination of CP-NaCMC followed by CP-HPMC and NaCMC-HPMC.  Decreasing the content of CP in CP-HPMC tablets or NaCMC in CP-NaCMC or NaCMC-HPMC systems resulted in decrease in detachment forces. Lower release rates were observed by lowering the content of CP in CP-HPMC containing formulations or NaCMC in tablets which contained CP-NaCMC or NaCMC-HPMC. The release behavior was non-Fickian controlled by a combination of diffusion and chain relaxation mechanisms and best fitted zero-order kinetics. Conclusion: The buccoadhesive VPH tablets containing 53% CP and 13.3% HPMC showed suitable release kinetics (n = 0.78, K0 zero order release = 4.11 mg/h, MDT = 5.66 h and adhesive properties and did not show any interaction between polymers and drug based on

Simultaneous Estimation of Gemcitabine Hydrochloride and Capecitabine Hydrochloride in Combined Tablet Dosage Form by RP-HPLC Method

Directory of Open Access Journals (Sweden)

V. Rajesh

2011-01-01

Full Text Available A new reverse phase high performance liquid chromatography (RP-HPLC method has been developed for the simultaneous estimation of gemcitabine hydrochloride and capecitabine hydrochloride in combined tablet dosage form. An inertsil ODS-3 C-18 column having dimensions of 250×4.6 mm and particle size of 5 µm, with mobile phase containing a mixture of acetonitrile : water : triethyelamine in the ratio of (70 : 28 : 2v/v was used. The pH of mobile phase was adjusted to 4.0 with ortho-phosphoric acid. The flow rate was 1 mL/min and the column effluents were monitored at 260 nm. The retention time for gemcitabine hydrochloride and capecitabine hydrochloride was found to be 2.76 and 2.3 min respectively. The proposed method was validated in terms of linearity, accuracy, precision, limit of detection, limit of quantitation and robustness. The method was found to be linear in the range of 10-50 µg/mL and 4-24 µg/mL for gemcitabine hydrochloride and capecitabine hydrochloride, with regression coefficient r = 0.999 and r = 0.999, respectively.

Carboxymethylated-, hydroxypropylsulfonated- and quaternized xylan derivative films

Science.gov (United States)

Ivan Simkovic; Ivan Kelnar; Iveta Uhliarikova; Raniero Mdndichi; Anurag Mandalika; Thomas Elder

2014-01-01

Under alkaline/water conditions carboxymethyl, 2-hydroxypropylsulfonate and trimethylammonium-2-hydroxypropyl groups were introduced into xylan in one step with the goal to prepare film specimens. The materials were characterized by NMR, SEC-MALS, TG/DTG/DTA, AFM and mechanical testing. The properties of triple, double and mono-substituted materials were compared. The...

40 CFR 721.10055 - 1-Propanaminium, 3-amino-N-(carboxymethyl)-N,N-dimethyl-, N-soya acyl derivs., inner salts.

Science.gov (United States)

2010-07-01

...-(carboxymethyl)-N,N-dimethyl-, N-soya acyl derivs., inner salts. 721.10055 Section 721.10055 Protection of...-amino-N-(carboxymethyl)-N,N-dimethyl-, N-soya acyl derivs., inner salts. (a) Chemical substance and...-(carboxymethyl)-N,N-dimethyl-, N-soya acyl derivs., inner salts (PMN P-03-46; CAS No. 136504-87-5) is subject to...

Functionalization of Magnetic Chitosan Particles for the Sorption of U(VI, Cu(II and Zn(II—Hydrazide Derivative of Glycine-Grafted Chitosan

Directory of Open Access Journals (Sweden)

Mohammed F. Hamza

2017-05-01

Full Text Available A new magnetic functionalized derivative of chitosan is synthesized and characterized for the sorption of metal ions (environmental applications and metal valorization. The chemical modification of the glycine derivative of chitosan consists of: activation of the magnetic support with epichlorohydrin, followed by reaction with either glycine to produce the reference material (i.e., Gly sorbent or glycine ester hydrochloride, followed by hydrazinolysis to synthesize the hydrazide functionalized sorbent (i.e., HGly sorbent. The materials are characterized by titration, elemental analysis, FTIR analysis (Fourrier-transform infrared spectrometry, TGA analysis (thermogravimetric analysis and with SEM-EDX (scanning electron microscopy coupled to energy dispersive X-ray analysis. The sorption performances for U(VI, Cu(II, and Zn(II are tested in batch systems. The sorption performances are compared for Gly and HGly taking into account the effect of pH, the uptake kinetics (fitted by the pseudo-second order rate equation, and the sorption isotherms (described by the Langmuir and the Sips equations. The sorption capacities of the modified sorbent reach up to 1.14 mmol U g−1, 1.69 mmol Cu g−1, and 0.85 mmol Zn g−1. In multi-metal solutions of equimolar concentration, the chemical modification changes the preferences for given metal ions. Metal ions are desorbed using 0.2 M HCl solutions and the sorbents are re-used for five cycles of sorption/desorption without significant loss in performances.

Synthesis and characterization of PEPO grafted carboxymethyl guar and carboxymethyl tamarind as new thermo-associating polymers.

Science.gov (United States)

Gupta, Nivika R; Torris A T, Arun; Wadgaonkar, Prakash P; Rajamohanan, P R; Ducouret, Guylaine; Hourdet, Dominique; Creton, Costantino; Badiger, Manohar V

2015-03-06

New thermo associating polymers were designed and synthesized by grafting amino terminated poly(ethylene oxide-co-propylene oxide) (PEPO) onto carboxymethyl guar (CMG) and carboxymethyl tamarind (CMT). The grafting was performed by coupling reaction between NH2 groups of PEPO and COOH groups of CMG and CMT using water-soluble EDC/NHS as coupling agents. The grafting efficiency and the temperature of thermo-association, T(assoc) in the copolymer were studied by NMR spectroscopy. The graft copolymers, CMG-g-PEPO and CMT-g-PEPO exhibited interesting thermo-associating behavior which was evidenced by the detailed rheological and fluorescence measurements. The visco-elastic properties (storage modulus, G'; loss modulus, G") of the copolymer solutions were investigated using oscillatory shear experiments. The influence of salt and surfactant on the T(assoc) was also studied by rheology, where the phenomenon of "Salting out" and "Salting in" was observed for salt and surfactant, respectively, which can give an easy access to tunable properties of these copolymers. These thermo-associating polymers with biodegradable nature of CMG and CMT can have potential applications as smart injectables in controlled release technology and as thickeners in cosmetics and pharmaceutical formulations. Copyright © 2014 Elsevier Ltd. All rights reserved.

21 CFR 522.1642 - Oxymorphone hydrochloride injection.

Science.gov (United States)

2010-04-01

... § 522.1642 Oxymorphone hydrochloride injection. (a) Specifications. The drug contains 1 or 1.5 milligrams of oxymorphone hydrochloride per milliliter of aqueous solution containing 0.8 percent sodium... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxymorphone hydrochloride injection. 522.1642...

21 CFR 522.536 - Detomidine hydrochloride injection.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Detomidine hydrochloride injection. 522.536... § 522.536 Detomidine hydrochloride injection. (a) Specification. Each milliliter of sterile aqueous solution contains 10 milligrams of detomidine hydrochloride. (b) Sponsor. See 052483 in § 510.600(c) of...

21 CFR 182.1047 - Glutamic acid hydrochloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Glutamic acid hydrochloride. 182.1047 Section 182.1047 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1047 Glutamic acid hydrochloride. (a) Product. Glutamic acid hydrochloride. (b...

Optimizing Extraction of Cellulose and Synthesizing Pharmaceutical Grade Carboxymethyl Sago Cellulose from Malaysian Sago Pulp

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Anand Kumar Veeramachineni

2016-06-01

Full Text Available Sago biomass is an agro-industrial waste produced in large quantities, mainly in the Asia-Pacific region and in particular South-East Asia. This work focuses on using sago biomass to obtain cellulose as the raw material, through chemical processing using acid hydrolysis, alkaline extraction, chlorination and bleaching, finally converting the material to pharmaceutical grade carboxymethyl sago cellulose (CMSC by carboxymethylation. The cellulose was evaluated using Thermogravimetric Analysis (TGA, Infrared Spectroscopy (FTIR, X-Ray Diffraction (XRD, Differential Scanning Calorimetry (DSC and Field Emission Scanning Electronic Microscopy (FESEM. The extracted cellulose was analyzed for cellulose composition, and subsequently modified to CMSC with a degree of substitution (DS 0.6 by typical carboxymethylation reactions. X-ray diffraction analysis indicated that the crystallinity of the sago cellulose was reduced after carboxymethylation. FTIR and NMR studies indicate that the hydroxyl groups of the cellulose fibers were etherified through carboxymethylation to produce CMSC. Further characterization of the cellulose and CMSC were performed using FESEM and DSC. The purity of CMSC was analyzed according to the American Society for Testing and Materials (ASTM International standards. In this case, acid and alkaline treatments coupled with high-pressure defibrillation were found to be effective in depolymerization and defibrillation of the cellulose fibers. The synthesized CMSC also shows no toxicity in the cell line studies and could be exploited as a pharmaceutical excipient.

Cartap hydrochloride poisoning: A clinical experience

OpenAIRE

Boorugu, Hari K.; Chrispal, Anugrah

2012-01-01

Cartap hydrochloride, a nereistoxin analog, is a commonly used low toxicity insecticide. We describe a patient who presented to the emergency department with alleged history of ingestion of Cartap hydrochloride as an act of deliberate self-harm. The patient was managed conservatively. To our knowledge this is the first case report of Cartap hydrochloride suicidal poisoning. Cartap toxicity has been considered to be minimal, but a number of animal models have shown significant neuromuscular to...

Radiation degradation of chitosan

International Nuclear Information System (INIS)

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

2010-01-01

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

In Vitro Osteogenic and Odontogenic Differentiation of Human Dental Pulp Stem Cells Seeded on Carboxymethyl Cellulose-Hydroxyapatite Hybrid Hydrogel.

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Gabriella eTeti

2015-10-01

Full Text Available Stem cells from human dental pulp have been considered as an alternative source of adult stem cells in tissue engineering because of their potential to differentiate into multiple cell lineages.Recently, polysaccharide based hydrogels have become especially attractive as matrices for the repair and regeneration of a wide variety of tissues and organs. The incorporation of inorganic minerals as hydroxyapatite nanoparticles can modulate the performance of the scaffolds with potential applications in tissue engineering. The aim of this study was to verify the osteogenic and odontogenic differentiation of dental pulp stem cells (DPSCs cultured on a carboxymethyl cellulose—hydroxyapatite hybrid hydrogel. Human DPSCs were seeded on carboxymethyl cellulose—hydroxyapatite hybrid hydrogel and on carboxymethyl cellulose hydrogel for 1, 3, 5, 7, 14 and 21 days. Cell viability assay and ultramorphological analysis were carried out to evaluate biocompatibility and cell adhesion. Real Time PCR was carried out to demonstrate the expression of osteogenic and odontogenic markers. Results showed a good adhesion and viability in cells cultured on carboxymethyl cellulose—hydroxyapatite hybrid hydrogel, while a low adhesion and viability was observed in cells cultured on carboxymethyl cellulose hydrogel. Real Time PCR data demonstrated a temporal up-regulation of osteogenic and odontogenic markers in dental pulp stem cells cultured on carboxymethyl cellulose—hydroxyapatite hybrid hydrogel. In conclusion, our in vitro data confirms the ability of DPSCs to differentiate toward osteogenic and odontogenic lineages in presence of a carboxymethyl cellulose—hydroxyapatite hybrid hydrogel. Taken together, our results provide evidence that DPSCs and carboxymethyl cellulose—hydroxyapatite hybrid hydrogel could be considered promising candidates for dental pulp complex and periodontal tissue engineering.

Adsorption mechanisms of carboxymethyl cellulose on mineral surfaces.

NARCIS (Netherlands)

Hoogendam, C.W.; Keizer, de A.; Cohen Stuart, M.A.; Bijsterbosch, B.H.; Batelaan, J.G.; Horst, van der P.M.

1998-01-01

The adsorption behavior of carboxymethyl cellulose (CMC) on inorganic surfaces (TiO2 and -Fe2O3) in aqueous solution has been studied systematically. The general trends are that the adsorbed amount decreases with increasing pH, whereas increasing the electrolyte (NaCl) concentration causes the

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

Science.gov (United States)

Rahmi; Marlina; Nisfayati

2018-05-01

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

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

International Nuclear Information System (INIS)

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

2017-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-02-28

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

21 CFR 520.1660b - Oxytetracycline hydrochloride capsules.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride capsules. 520.1660b... Oxytetracycline hydrochloride capsules. (a) Specifications. The drug is in capsule form with each capsule containing 125 or 250 milligrams of oxytetracycline hydrochloride. Oxytetracycline is the antibiotic...

Impedance spectroscopy study of dehydrated chitosan and chitosan containing LiClO4

International Nuclear Information System (INIS)

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

2010-01-01

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

21 CFR 522.1662a - Oxytetracycline hydrochloride injection.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride injection. 522.1662a... § 522.1662a Oxytetracycline hydrochloride injection. (a)(1) Specifications. The drug contains 50 milligrams of oxytetracycline hydrochloride in each milliliter of sterile solution. (2) Sponsor. See No...

Immobilisation of impala (Aepyceros melampus with a ketamine hydrochloride / medetomidine hydrochloride combination, and reversal with atipamezole hydrochloride

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M. Bush

2004-06-01

Full Text Available A combination of medetomidine hydrochloride (medetomidine and ketamine hydrochloride (ketamine was evaluated in 16 boma-confined and 19 free-ranging impalas (Aepyceros melampus to develop a non-opiate immobilisation protocol. In free-ranging impala a dose of 220 + 34 mg/kg medetomidine and 4.4 + 0.7 mg/kg ketamine combined with 7500 IU of hyaluronidase induced recumbency within 4.5+1.5 min, with good muscle relaxation, a stable heart rate and blood pH. PaCO2 was maintained within acceptable ranges. The animals were hypoxic with reduced oxygen saturation and low PaO2 in the presence of an elevated respiration rate, therefore methods for respiratory support are indicated. The depth of sedation was adequate for minor manipulations but additional anaesthesia is indicated for painful manipulations. Immobilisation was reversed by 467 + 108 mg/kg atipamezole hydrochloride (atipamezole intramuscularly, but re-sedation was observed several hours later, possibly due to a low atipamezole:medetomidine ratio of 2:1. Therefore, this immobilisation and reversal protocol would subject impalas to possible predation or conspecific aggression following reversal if they were released into the wild. If the protocol is used on free-ranging impala, an atipamezole:medetomidine ratio of 5:1 should probably be used to prevent re-sedation.

[Evaluation of the influence of sterilization method on the stability of carboxymethyl cellulose wound dressing].

Science.gov (United States)

Muselík, Jan; Wojnarová, Lenka; Masteiková, Ruta; Sopuch, Tomáš

2013-04-01

Carboxymethyl cellulose, especially its sodium salt, is a versatile pharmaceutical excipient. From a therapeutic point of view, sodium salt of carboxymethyl cellulose is used in the production of modern wound dressings to allow moist wound healing. Wound dressings must be sterile and stable throughout their shelf life and have to be able to withstand different temperature conditions. At the present time, a number of sterilization methods are available. In the case of polymeric materials, the selected sterilization process must not induce any changes in the polymer structure, such as polymer chains cleavage, changes in cross-linking, etc. This paper evaluates the influence of different sterilization methods (γ-radiation, β-radiation, ethylene oxide) on the stability of carboxymethyl cellulose and the results of long-term and accelerated stability testing. Evaluation of samples was performed using size-exclusion chromatography. The obtained results showed that ethylene oxide sterilization was the least aggressive variant of the sterilization methods tested. When the γ-radiation sterilization was used, the changes in the size of the carboxymethyl cellulose molecule occurred. In the course of accelerated and long term stability studies, no further degradation changes were observed, and thus sterilized samples are suitable for long term storage.

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

Science.gov (United States)

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

2018-04-01

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

Preparation of venlafaxine hydrochloride sustained-release tablets

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GUO Lingling

2013-08-01

Full Text Available To prepare venlafxine hydrochloride sustained-release tablets.Hydroxypropylmethyl cellulose(HPMC and methyl cellulose(MC were used as main materials to prepare sustained-release tablets of velafaxine hydrochloride and the influence of important factors on in vitro release curves of venlafaxine hydrochloride sustained-release tablets was investigated.Results:The optimal prescription included 100 mg HPMC,25 mg MC,and 2.5% glidant in one tablet prepared with 30kN.The tablets were prepared with the method of wet granulation by NO.16 mesh sieve.The tablets exhibited good sustained-release property in phosphate buffered solution (pH=6.8.The as-prepared venlafxine hydrochloride sustained-release tablets have good sustained-release property.

Carboxymethyl-cellulase from Erwinia chrysanthemi. II. Purification and partial characterization of an endo-. beta. -1,4-glucanase

Energy Technology Data Exchange (ETDEWEB)

Boyer, M.H.; Chambost, J.P.; Magnan, M.; Cattaneo, J.

1984-01-01

The extracellular carboxymethyl-cellulase of Erwinia chrysanthemi, strain 3665, had a marked tendency to form aggregates when concentration and/or storage time of culture supernatant were increased. In submitting an unconcentrated glycerol culture supernatant to ion exchange chromatography, one major endo-..beta..-1,4,-glucanase could be isolated with a high degree of purity and partially characterized. The molecular size was 45 kd. The pI was 4.3. The enzyme rapidly decreased the viscosity of carboxymethyl-cellulose with a slow increase in the reducing sugars produced. It displayed its highest activity towards carboxymethyl-cellulose at a pH between 6.2 and 7.5. It had a significant capacity to hydrolyze amorphous cellulose such as phosphoric acid-swollen cellulose. The major products of this degradation were cellobiose and cellotriose. It exhibited a very low activity on microcrystalline cellulose. Glucose and cellobiose did not affect significantly its activity against carboxymethyl-cellulose. 21 references.

Use of 6α- and 6β-carboxymethyl testosterone-bovine serum albumin conjugates in radioimmunoassay for testosterone

International Nuclear Information System (INIS)

Jones, C.D.; Mason, N.R.

1975-01-01

The synthesis of 6α- and 6β-testosterone-bovine serum albumin (BSA) conjugates is described. 6β-Carboxymethyl-4-androstene-3,17-dione was prepared by a route analogous to that described earlier for 6β-carboxymethyl progesterone. Sodium borohydride reduction of the 3 and 17 keto groups and subsequent selective oxidation of the resulting 3β,17β-diol using MnO 2 provided 6β-carboxymethyl testosterone. Further acid catalyzed epimerization of the C-6 center gave the isomeric 6α-carboxymethyl testosterone. The 6α- and 6β-testosterone derivatives were attached to BSA via a mixed anhydride coupling employing tributylamine and i-butylchlorocarbonate. For each molecule of BSA, the 6α- and 6β-conjugates contained an average of 23 and 20 steroid residues, respectively. Antisera to the conjugates exhibited similar high specificities toward various steroids, the only incidence of serious cross-reaction being the expected case of dihydrotestosterone. (U.S.)

Drug Loading and Release Behavior Depending on the Induced Porosity of Chitosan/Cellulose Multilayer Nanofilms.

Science.gov (United States)

Park, Sohyeon; Choi, Daheui; Jeong, Hyejoong; Heo, Jiwoong; Hong, Jinkee

2017-10-02

The ability to control drug loading and release is the most important feature in the development of medical devices. In this research, we prepared a functional nanocoating technology to incorporate a drug-release layer onto a desired substrate. The multilayer films were prepared using chitosan (CHI) and carboxymethyl cellulose (CMC) polysaccharides by the layer-by-layer (LbL) method. By using chemical cross-linking to change the inner structure of the assembled multilayer, we could control the extent of drug loading and release. The cross-linked multilayer film had a porous structure and enhanced water wettability. Interestingly, more of the small-molecule drug was loaded into and released from the non-cross-linked multilayer film, whereas more of the macromolecular drug was loaded into and released from the cross-linked multilayer film. These results indicate that drug loading and release can be easily controlled according to the molecular weight of the desired drug by changing the structure of the film.

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

Science.gov (United States)

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

2017-12-01

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

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

Science.gov (United States)

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

2017-08-01

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

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

Directory of Open Access Journals (Sweden)

Ana V Oliveira

2013-01-01

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

Investigation of Carboxymethyl Cellulose (CMC on Mechanical Properties of Cold Water Fish Gelatin Biodegradable Edible Films

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Mahsa Tabari

2017-05-01

Full Text Available The tendency to use biocompatible packages, such as biodegradable films, is growing since they contain natural materials, are recyclable and do not cause environmental pollution. In this research, cold water fish gelatin and carboxymethyl cellulose were combined for use in edible films. Due to its unique properties, gelatin is widely used in creating gel, and in restructuring, stabilizing, emulsifying, and forming foam and film in food industries. This research for the first time modified and improved the mechanical properties of cold water fish gelatin films in combination with carboxymethyl cellulose. Cold water fish gelatin films along with carboxymethyl cellulose with concentrations of 0%, 5%, 10%, 20% and 50% were prepared using the casting method. The mechanical properties were tested by the American National Standard Method. Studying the absorption isotherm of the resulting composite films specified that the humidity of single-layer water decreased (p < 0.05 and caused a reduction in the equilibrium moisture of these films. In the mechanical testing of the composite films, the tensile strength and Young’s modulus significantly increased and the elongation percent significantly decreased with the increase in the concentration of carboxymethyl cellulose. Considering the biodegradability of the films and the improvement of their mechanical properties by carboxymethyl cellulose, this kind of packaging can be used in different industries, especially the food industry, as an edible coating for packaging food and agricultural crops.

Acute Psychotic Symptoms due to Benzydamine Hydrochloride Abuse with Alcohol

Directory of Open Access Journals (Sweden)

Yahya Ayhan Acar

2014-01-01

Full Text Available Benzydamine hydrochloride is a locally acting nonsteroidal anti-inflammatory drug. Benzydamine hydrochloride overdose can cause stimulation of central nervous system, hallucinations, and psychosis. We presented a young man with psychotic symptoms due to benzydamine hydrochloride abuse. He received a total dose of 1000 mg benzydamine hydrochloride with alcohol for its hallucinative effects. Misuse of benzydamine hydrochloride must be considered in differential diagnosis of first-episode psychosis and physicians should consider possibility of abuse in prescribing.

Synthesis and characterization of carboxymethyl potato starch and its application in reactive dye printing.

Science.gov (United States)

Zhang, Bing; Gong, Honghong; Lü, Shaoyu; Ni, Boli; Liu, Mingzhu; Gao, Chunmei; Huang, Yinjuan; Han, Fei

2012-11-01

Carboxymethyl potato starch (CMPS) was synthesized with a simple dry and multi-step method as a product of the reaction of native potato starch and monochloroacetic acid in the presence of sodium hydroxide. The influence of the molar ratio of sodium hydroxide to anhydroglucose unit, the volume of 95% (v/v) ethanol, the rotation rate of motor driven stirrer and the reaction time for degree of substitution (DS) were evaluated. The product was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffractometry (XRD). FTIR spectrometry showed new bonds at 1618 and 1424 cm⁻¹ when native starch underwent carboxymethylation. SEM pictures showed that the smooth surface of native starch particles was mostly ruptured. XRD revealed that starch crystallinity was reduced after carboxymethylation. The viscosity of the mixture paste of carboxymethyl starch and sodium alginate (SA) was measured using a rotational viscometer. In addition, the applied effect of mixed paste in reactive dye printing was examined by assessing the fabric stiffness, color yield and sharp edge to the printed image in comparison with SA. And the results indicated that the mixed paste could partially replace SA as thickener in reactive dye printing. The study also showed that the method was low cost and eco-friendly and the product would have an extensive application in reactive dye printing. Copyright © 2012 Elsevier B.V. All rights reserved.

Cartap hydrochloride poisoning: A clinical experience.

Science.gov (United States)

Boorugu, Hari K; Chrispal, Anugrah

2012-01-01

Cartap hydrochloride, a nereistoxin analog, is a commonly used low toxicity insecticide. We describe a patient who presented to the emergency department with alleged history of ingestion of Cartap hydrochloride as an act of deliberate self-harm. The patient was managed conservatively. To our knowledge this is the first case report of Cartap hydrochloride suicidal poisoning. Cartap toxicity has been considered to be minimal, but a number of animal models have shown significant neuromuscular toxicity resulting in respiratory failure. It is hypothesized that the primary effect of Cartap hydrochloride is through inhibition of the [(3)H]-ryanodine binding to the Ca(2+) release channel in the sarcoplasmic reticulum in a dose-dependent manner and promotion of extracellular Ca(2+) influx and induction of internal Ca(2+) release. This results in tonic diaphragmatic contraction rather than paralysis. This is the basis of the clinical presentation of acute Cartap poisoning as well as the treatment with chelators namely British Anti Lewisite and sodium dimercaptopropane sulfonate.

Biophysical properties of carboxymethyl derivatives of mannan and dextran.

Science.gov (United States)

Korcová, Jana; Machová, Eva; Filip, Jaroslav; Bystrický, Slavomír

2015-12-10

Mannan from Candida albicans, dextran from Leuconostoc spp. and their carboxymethyl (CM)-derivatives were tested on antioxidant and thrombolytic activities. As antioxidant tests, protection of liposomes against OH radicals and reducing power assay were used. Dextran and mannan protected liposomes in dose-dependent manner. Carboxymethylation significantly increased antioxidant properties of both CM-derivatives up to concentration of 10mg/mL, higher concentrations did not change the protection of liposomes. The reducing power of CM-mannan (DS 0.92) was significantly lower (Pdextran and CM-dextran. All CM-derivatives demonstrated statistically significant increasing activity compared with underivatized polysaccharides. The highest thrombolytic activity was found using CM-mannan (DS 0.92). The clot lysis here amounted to 68.78 ± 6.52% compared with 0.9% NaCl control (18.3 ± 6.3%). Three-dimensional surface profiles of mannan, dextran, and their CM-derivatives were compared by atomic force microscopy. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of Carboxymethylation on the Rheological Properties of Hyaluronan.

Science.gov (United States)

Wendling, Rian J; Christensen, Amanda M; Quast, Arthur D; Atzet, Sarah K; Mann, Brenda K

2016-01-01

Chemical modifications made to hyaluronan to enable covalent crosslinking to form a hydrogel or to attach other molecules may alter the physical properties as well, which have physiological importance. Here we created carboxymethyl hyaluronan (CMHA) with varied degree of modification and investigated the effect on the viscosity of CMHA solutions. Viscosity decreased initially as modification increased, with a minimum viscosity for about 30-40% modification. This was followed by an increase in viscosity around 45-50% modification. The pH of the solution had a variable effect on viscosity, depending on the degree of carboxymethyl modification and buffer. The presence of phosphates in the buffer led to decreased viscosity. We also compared large-scale production lots of CMHA to lab-scale and found that large-scale required extended reaction times to achieve the same degree of modification. Finally, thiolated CMHA was disulfide crosslinked to create hydrogels with increased viscosity and shear-thinning aspects compared to CMHA solutions.

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

International Nuclear Information System (INIS)

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

2015-01-01

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

Preparation of carboxymethyl cellulose produced from purun tikus (Eleocharis dulcis)

Science.gov (United States)

Sunardi, Febriani, Nina Mutia; Junaidi, Ahmad Budi

2017-08-01

Sodium carboxymethyl cellulose (Na-CMC) is one of the important modified cellulose, a water-soluble cellulose, which is widely used in many application of food, pharmaceuticals, detergent, paper coating, dispersing agent, and others. The main raw material of modified cellulose is cellulose from wood and cotton. Recently, much attention has been attracted to the use of various agriculture product and by-product, grass, and residual biomass as cellulose and modified cellulose source for addressing an environmental and economic concern. Eleocharis dulcis, commonly known as purun tikus (in Indonesia), is a native aquatic plant of swamp area (wetland) in Kalimantan, which consists of 30-40% cellulose. It is significantly considered as one of the alternative resources for cellulose. The aims of present study were to isolate cellulose from E. dulcis and then to synthesise Na-CMC from isolated cellulose. Preparation of carboxymethyl cellulose from E. dulcis was carried out by an alkalization and etherification process of isolated cellulose, using various concentration of sodium hydroxide (NaOH) and monochloroacetic acid (MCA). The results indicated that the optimum reaction of alkalization was reached at 20% NaOH and etherification at the mass fraction ratio of MCA to cellulose 1.0. The optimum reaction has the highest solubility and degree of substitution. The carboxymethylation process of cellulose was confirmed by Fourier Transform Infrared spectroscopy (FTIR). In addition, changes in crystallinity of cellulose and Na-CMC were evaluated by X-ray diffraction (XRD).

Gelatin/chitosan biofilm: preparation and characterization

International Nuclear Information System (INIS)

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

2011-01-01

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

Carboxymethyl Cellulose From Kenaf Reinforced Composite Polymer Electrolytes Based 49 % Poly (Methyl Methacrylate)-Grafted Natural Rubber

International Nuclear Information System (INIS)

Serawati Jafirin; Ishak Ahmad; Azizan Ahmad; Ishak Ahmad; Azizan Ahmad

2014-01-01

Composite polymer electrolytes based 49 % poly(methyl methacrylate)-grafted natural rubber (MG49) incorporating lithium triflate (LiCF 3 SO 3 ) were prepared. The study mainly focuses on the ionic conductivity performances and mechanical properties. Prior to that, carboxymethyl cellulose was synthesized from kenaf fiber. The films were characterized by electrochemical impedance (EIS) spectroscopy, linear sweep voltammetry (LSV), universal testing machine and scanning electron microscopy (SEM). The conductivity was found to increase with carboxymethyl cellulose loading. The highest conductivity value achieved was 6.5 x 10 -6 Scm -1 upon addition of 6 wt % carboxymethyl cellulose. LSV graph shows the stability of this film was extended to 2.7 V at room temperature. The composition with 6 wt % carboxymethyl cellulose composition showed the highest tensile strength value of 7.9 MPa and 273 MPa of Young's modulus. The morphology of the electrolytes showed a smooth surface of films after addition of salt and filler indicating amorphous phase in electrolytes system. Excellent mechanical properties and good ionic conductivity are obtained, enlightening that the film is suitable for future applications as thin solid polymer electrolytes in lithium batteries. (author)

Fabrication of chitosan microparticles loaded in chitosan and poly

Indian Academy of Sciences (India)

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

Spectrophotometric determination of procainamide hydrochloride using sodium periodate

Directory of Open Access Journals (Sweden)

S. Al-Tamrah

2015-09-01

Full Text Available A simple spectrophotometric method has been described for the determination of procainamide hydrochloride. The method is based on the oxidation of procainamide hydrochloride by sodium periodate in the presence of sulfuric acid and measurement of the absorbance of the violet color formed at 531 nm. Parameters affecting the reaction were studied and conditions were optimized. Linear calibration graph was obtained from 50 to 700 μg ml−1 of procainamide hydrochloride and the limit of detection was 25 μg ml−1. The method was successfully applied for the determination of procainamide hydrochloride in pharmaceutical preparation.

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

Science.gov (United States)

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

2017-06-01

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

21 CFR 520.1660c - Oxytetracycline hydrochloride tablets/boluses.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride tablets/boluses. 520....1660c Oxytetracycline hydrochloride tablets/boluses. (a) Specifications. Each tablet or bolus contains 250, 500, or 1,000 milligrams of oxytetracycline hydrochloride. (b) Sponsors. For sponsors in § 510...

Encapsulation of testosterone by chitosan nanoparticles.

Science.gov (United States)

Chanphai, P; Tajmir-Riahi, H A

2017-05-01

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

Comparative Efficacy Of 1% Terbinafine Hydrochloride And 1% Butenafine Hydrochloride Cream In The Treatment Of Tinea Cruris

Directory of Open Access Journals (Sweden)

Rathi Sanjay K

2001-01-01

Full Text Available The aim of the study was to evaluate the comparative efficacy of 1% terbinafine hydrochloride and 1% butenafine hydrochloride cream in the treatment of Tinea cruris, was done taking with ten patients in each study group. They were found to be equipotent in one and two weeks treatment respectively.

Thermodynamic studies of drug–α-cyclodextrin interactions in water at 298.15 K: Procaine hydrochloride/lidocaine hydrochloride/tetracaine hydrochloride/ranitidine hydrochloride + α-cyclodextrin + H2O systems

International Nuclear Information System (INIS)

Shaikh, Vasim R.; Terdale, Santosh S.; Hundiwale, Dilip G.; Patil, Kesharsingh J.

2014-01-01

Graphical abstract: The encapsulation of guest tetracaine hydrochloride TC·HCl (C 15 H 24 N 2 O 2 ·HCl), in α-cyclodextrin cavities in aqueous solutions at 298.15 K. -- Highlights: • The osmotic coefficient measurements are reported for PC·HCl/LC·HCl/TC·HCl/RT·HCl + 0.1 m α-CD + water at 298.15 K. • The concentration variation of mean activity coefficients of drug molecules in water–α-CD solutions has been studied. • The transfer Gibbs free energies have been calculated using the activity data. • Pair and triplet interaction parameters and equilibrium constant (log K) values are also estimated. • The results are discussed with emphasis on host–guest interaction concepts. -- Abstract: The osmotic coefficient measurements have been carried out for ternary aqueous solutions containing a fixed concentration of α-cyclodextrin (α-CD) of ∼0.1 mol · kg −1 and varying the concentrations (∼0.012 to ∼0.21 mol · kg −1 ) of drugs Procaine hydrochloride (PC·HCl), Lidocaine hydrochloride (LC·HCl), Tetracaine hydrochloride (TC·HCl) and Ranitidine hydrochloride (RT·HCl) at 298.15 K using vapour pressure osmometry. The water activities for each ternary system were measured and used to obtain the activity coefficients of α-cyclodextrin (α-CD) and drugs following the methodology developed by Robinson and Stokes for isopiestic measurements. The transfer Gibbs free energies of electrolyte (or drug) from water to an aqueous nonelectrolyte (α-CD) solutions (ΔG tr E ) and that of nonelectrolyte (α-CD) from water to an aqueous electrolyte (or drug) solutions (ΔG tr N ) have been calculated using the activity data. These were further used for the estimation of pair and triplet interaction parameters. By applying the method based on the application of the McMillan–Mayer theory of virial coefficients to transfer free energy data, the salting constant (k s ) values have been estimated at 298.15 K. The equilibrium constant (log K) values for the

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

Directory of Open Access Journals (Sweden)

Yolanda Osuna

2012-01-01

Full Text Available Chitosan-coated magnetic nanoparticles (CMNP were obtained at 50°C in a one-step method comprising coprecipitation in the presence of low chitosan content. CMNP showed high magnetization and superparamagnetism. They were composed of a core of 9.5 nm in average diameter and a very thin chitosan layer in accordance with electron microscopy measurements. The results from Fourier transform infrared spectrometry demonstrated that CMNP were obtained and those from thermogravimetric analysis allowed to determine that they were composed of 95 wt% of magnetic nanoparticles and 5 wt% of chitosan. 67% efficacy in the Pb+2 removal test indicated that only 60% of amino groups on CMNP surface bound to Pb, probably due to some degree of nanoparticle flocculation during the redispersion. The very low weight ratio chitosan to magnetic nanoparticles obtained in this study, 0.053, and the high yield of the precipitation reactions (≈97% are noticeable.

Structure and properties of microcrystalline chitosan

International Nuclear Information System (INIS)

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

2016-01-01

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

Structure and properties of microcrystalline chitosan

Energy Technology Data Exchange (ETDEWEB)

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

2016-07-01

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

Pseudo-thermosetting chitosan hydrogels for biomedical application.

Science.gov (United States)

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

2005-01-06

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

Preparation and evaluation of doxycycline hydrochloride and bromhexine hydrochloride dosage forms for pigeons / Marga le Roux

OpenAIRE

Le Roux, Marga

2004-01-01

Objective: To prepare and evaluate three different dosage forms, containing doxycycline hydrochloride (HCI) and bromhexine hydrochloride (HCI) respectively and in combination, for the treatment of respiratory diseases in pigeons. Background: Birds have held a place in man's affection since the ancient Egyptians and Romans kept birds. Europeans have successfully bred birds, especially smaller birds and pigeons, for centuries. Only in recent years, however, have science and me...

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

Science.gov (United States)

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

2015-05-01

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

Green synthesis of palladium nanoparticles with carboxymethyl cellulose for degradation of azo-dyes

Energy Technology Data Exchange (ETDEWEB)

Li, Gang; Li, Yun; Wang, Zhengdong; Liu, Huihong, E-mail: huihongliu@126.com

2017-02-01

Palladium nanoparticles (PdNPs) were synthesized through friendly environmental method using PdCl{sub 2} and carboxymethyl cellulose (CMC) in an aqueous solution (pH 6) at controlled water bath (80 °C) for 30 min. CMC functioned as both reducing and stabilizing agent. The characterization through high resolution-transmission electron microscopic (HRTEM) and X-ray Fluorescence Spectrometry (XRF) inferred that the as-synthesized PdNPs were spherical in shape with a face cubic crystal (FCC) structure. The results from dynamic light scattering (DLS) suggested the PdNPs had the narrow size distribution with an average size of 2.5 nm. The negative zeta potential (−52.6 mV) kept the as-synthesized PdNPs stable more than one year. The PdNPs showed the excellent catalytic activity by reducing degradation of azo-dyes, such as p-Aminoazobenzene, acid red 66, acid orange 7, scarlet 3G and reactive yellow 179, in the present of sodium borohydride. - Highlights: • Green synthesis of palladium nanoparticles using carboxymethyl cellulose. • The synthesis of palladium nanoparticles were performed easily. • Carboxymethyl cellulose acts as both reducing and stabilization agents. • The as-synthesized palladium nanoparticles show excellent catalytic activity.

Two simple amine hydrochlorides from the soft coral Lobophytum strictum

Digital Repository Service at National Institute of Oceanography (India)

Parameswaran, P.S.; Naik; Das, B.; Kamat, S.Y.

Two simple amine hydrochlorides, viz., 1-amino-1, 1-dimethyl-3-oxo-butane hydrochloride (1) (Diacetonamine) and 2, 2, 6, 6-tetramethylpiperidone hydrochloride (2) have been isolated from the fraction of the methanolic extract of the soft coral...

The formation of magnetic carboxymethyl-dextrane-coated iron-oxide nanoparticles using precipitation from an aqueous solution

International Nuclear Information System (INIS)

Makovec, Darko; Gyergyek, Sašo; Primc, Darinka; Plantan, Ivan

2015-01-01

The formation of spinel iron-oxide nanoparticles during the co-precipitation of Fe 3+ /Fe 2+ ions from an aqueous solution in the presence of carboxymethyldextrane (CMD) was studied. To follow the formation of the nanoparticles, a mixture of the Fe ions, CMD and ammonia was heated to different temperatures, while the samples were taken, quenched in liquid nitrogen, freeze-dried and characterized using transmission electron microscopy (TEM), X-ray diffractometry (XRD) and magnetometry. The CMD plays a role in the reactions of the Fe ions' precipitation by partially immobilizing the Fe 3+ ions into a complex. At room temperature, the amorphous material is precipitated. Then, above approximately 30 °C, the spinel nanoparticles form inside the amorphous matrix, and at approximately 40 °C the matrix decomposes into the suspension of carboxymethyl-dextrane-coated iron-oxide nanoparticles. The CMD bonded to the nanoparticles' surfaces hinders the mass transport and thus prevents their growth. - Highlights: • The carboxymethyl-dextrane coated iron-oxide nanoparticles were synthesized. • The carboxymethyl-dextrane significantly modifies formation of the spinel nanoparticles. • The spinel nanoparticles are formed inside the amorphous matrix. • At approximately 40 °C the matrix decomposes into the suspension of carboxymethyl-dextrane-coated iron-oxide nanoparticles

The formation of magnetic carboxymethyl-dextrane-coated iron-oxide nanoparticles using precipitation from an aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Makovec, Darko [Department for Materials Synthesis, Jožef Stefan Institute, Jamova ulica 39, SI-1000 Ljubljana (Slovenia); Gyergyek, Sašo, E-mail: saso.gyergyek@ijs.si [Department for Materials Synthesis, Jožef Stefan Institute, Jamova ulica 39, SI-1000 Ljubljana (Slovenia); Primc, Darinka [Department for Materials Synthesis, Jožef Stefan Institute, Jamova ulica 39, SI-1000 Ljubljana (Slovenia); Plantan, Ivan [Lek Pharmaceuticals d.d., Mengeš (Slovenia)

2015-03-01

The formation of spinel iron-oxide nanoparticles during the co-precipitation of Fe{sup 3+}/Fe{sup 2+} ions from an aqueous solution in the presence of carboxymethyldextrane (CMD) was studied. To follow the formation of the nanoparticles, a mixture of the Fe ions, CMD and ammonia was heated to different temperatures, while the samples were taken, quenched in liquid nitrogen, freeze-dried and characterized using transmission electron microscopy (TEM), X-ray diffractometry (XRD) and magnetometry. The CMD plays a role in the reactions of the Fe ions' precipitation by partially immobilizing the Fe{sup 3+} ions into a complex. At room temperature, the amorphous material is precipitated. Then, above approximately 30 °C, the spinel nanoparticles form inside the amorphous matrix, and at approximately 40 °C the matrix decomposes into the suspension of carboxymethyl-dextrane-coated iron-oxide nanoparticles. The CMD bonded to the nanoparticles' surfaces hinders the mass transport and thus prevents their growth. - Highlights: • The carboxymethyl-dextrane coated iron-oxide nanoparticles were synthesized. • The carboxymethyl-dextrane significantly modifies formation of the spinel nanoparticles. • The spinel nanoparticles are formed inside the amorphous matrix. • At approximately 40 °C the matrix decomposes into the suspension of carboxymethyl-dextrane-coated iron-oxide nanoparticles.

Degree of corneal anaesthesia after topical application of 0.4% oxybuprocaine hydrochloride and 0.5% proparacaine hydrochloride ophthalmic solution in clinically normal cattle.

Science.gov (United States)

Little, W B; Jean, G St; Sithole, F; Little, E; Jean, K Yvorchuk-St

2016-06-01

The use of corneal anaesthesia is necessary for a range of clinical purposes. Therefore, we assessed and compared the efficacy of corneal anaesthesia after application of 0.4% oxybuprocaine hydrochloride and 0.5% proparacaine hydrochloride ophthalmic solution in clinically normal cattle. The 24 clinically normal cows were allocated into two groups. Cows in group 1 (n = 12) received 0.2 mL of 0.4% oxybuprocaine hydrochloride with fluorescein ophthalmic solution in one eye and 0.2 mL of sterile saline (0.9% NaCl) with fluorescein in the contralateral eye (control). Group 2 (n = 12) received 0.2 mL of 0.4% oxybuprocaine hydrochloride with fluorescein ophthalmic solution in one eye and 0.2 mL of 0.5% proparacaine hydrochloride with fluorescein in the contralateral eye (control). In each group, corneal touch threshold was determined by Cochet-Bonnet aesthesiometer for both eyes immediately prior to topical administration of solutions, at 1 min and 5 min after administration of topical solutions and every 5 min thereafter for a total of 75 min. Significant corneal anaesthesia was noted immediately following topical application of both oxybuprocaine and proparacaine as compared with controls, with maximal corneal anaesthesia noted 1 min after administration. Both oxybuprocaine and proparacaine produced significant corneal anaesthesia for the duration of the 75-min study. Neither oxybuprocaine hydrochloride nor proparacaine hydrochloride treatment resulted in visible adverse effects. There are limited data available demonstrating the efficacy and duration of corneal anaesthetic agents in cattle. Both oxybuprocaine hydrochloride and proparacaine hydrochloride should be considered practical options for providing corneal anaesthesia in cattle in a clinical setting. © 2016 Australian Veterinary Association.

21 CFR 524.1662a - Oxytetracycline hydrochloride and hydrocortisone spray.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride and hydrocortisone... NEW ANIMAL DRUGS § 524.1662a Oxytetracycline hydrochloride and hydrocortisone spray. (a) Specifications. Each 3-ounce unit of oxytetracycline hydrochloride and hydrocortisone spray contains 300...

Carboxymethyl starch/montmorillonite composite microparticles: Properties and controlled release of isoproturon.

Science.gov (United States)

Wilpiszewska, Katarzyna; Spychaj, Tadeusz; Paździoch, Waldemar

2016-01-20

Preparation of novel high substituted carboxymethyl starch-based microparticles containing sodium montmorillonite (MMT) by crosslinking with Al(3+) was described. For preparing nanocomposite granules carboxymethyl starch (CMS) from native potato starch as well as CMS from amylopectin has been used. The hydrophilic CMS/MMT composite systems were used for herbicide, i.e. isoproturon encapsulation (ca. 75% encapsulation efficiency). The herbicide release rate from CMS/MMT composites in water was significantly reduced when compared to commercial isoproturon: 95% released after ca. 700 h and ca. 24h, respectively. Leaching in soil from composite systems was relatively slower than release in water. After a series of eight irrigations leached about 10% of isoproturon loaded. The CMS/MMT carriers could reduce the potential leaching of herbicide and beneficially reduce pollution of the environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Accelerometric comparison of the locomotor pattern of horses sedated with xylazine hydrochloride, detomidine hydrochloride, or romifidine hydrochloride.

Science.gov (United States)

López-Sanromán, F Javier; Holmbak-Petersen, Ronald; Varela, Marta; del Alamo, Ana M; Santiago, Isabel

2013-06-01

To evaluate the duration of effects on movement patterns of horses after sedation with equipotent doses of xylazine hydrochloride, detomidine hydrochloride, or romifidine hydrochloride and determine whether accelerometry can be used to quantify differences among drug treatments. 6 healthy horses. Each horse was injected IV with saline (0.9% NaCl) solution (10 mL), xylazine diluted in saline solution (0.5 mg/kg), detomidine diluted in saline solution (0.01 mg/kg), or romifidine diluted in saline solution (0.04 mg/kg) in random order. A triaxial accelerometric device was used for gait assessment 15 minutes before and 5, 15, 30, 45, 60, 75, 90, 105, and 120 minutes after each treatment. Eight variables were calculated, including speed, stride frequency, stride length, regularity, dorsoventral power, propulsive power, mediolateral power, and total power; the force of acceleration and 3 components of power were then calculated. Significant differences were evident in stride frequency and regularity between treatments with saline solution and each α2-adrenoceptor agonist drug; in speed, dorsoventral power, propulsive power, total power, and force values between treatments with saline solution and detomidine or romifidine; and in mediolateral power between treatments with saline solution and detomidine. Stride length did not differ among treatments. Accelerometric evaluation of horses administered α2-adrenoceptor agonist drugs revealed more prolonged sedative effects of romifidine, compared with effects of xylazine or detomidine. Accelerometry could be useful in assessing the effects of other sedatives and analgesics. Accelerometric data may be helpful in drug selection for situations in which a horse's balance and coordination are important.

21 CFR 522.1662b - Oxytetracycline hydrochloride with lidocaine injection.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride with lidocaine... FORM NEW ANIMAL DRUGS § 522.1662b Oxytetracycline hydrochloride with lidocaine injection. (a) Specifications. The drug contains 50 or 100 milligrams of oxytetracycline hydrochloride and 2 percent lidocaine...

Spectrophotometric determination of procainamide hydrochloride using sodium periodate

OpenAIRE

Al-Tamrah, S.; Al-Abbad, S.

2015-01-01

A simple spectrophotometric method has been described for the determination of procainamide hydrochloride. The method is based on the oxidation of procainamide hydrochloride by sodium periodate in the presence of sulfuric acid and measurement of the absorbance of the violet color formed at 531 nm. Parameters affecting the reaction were studied and conditions were optimized. Linear calibration graph was obtained from 50 to 700 μg ml−1 of procainamide hydrochloride and the limit of detection wa...

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

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Nafise Sadat Majidi

2016-09-01

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

Chitosan Modification and Pharmaceutical/Biomedical Applications

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Jiali Zhang

2010-06-01

Full Text Available Chitosan has received much attention as a functional biopolymer for diverse applications, especially in pharmaceutics and medicine. Our recent efforts focused on the chemical and biological modification of chitosan in order to increase its solubility in aqueous solutions and absorbability in the in vivo system, thus for a better use of chitosan. This review summarizes chitosan modification and its pharmaceutical/biomedical applications based on our achievements as well as the domestic and overseas developments: (1 enzymatic preparation of low molecular weight chitosans/chitooligosaccharides with their hypocholesterolemic and immuno-modulating effects; (2 the effects of chitin, chitosan and their derivatives on blood hemostasis; and (3 synthesis of a non-toxic ion ligand—D-Glucosaminic acid from Oxidation of D-Glucosamine for cancer and diabetes therapy.

In situ gelling dorzolamide loaded chitosan nanoparticles for the treatment of glaucoma.

Science.gov (United States)

Katiyar, Shefali; Pandit, Jayamanti; Mondal, Rabi S; Mishra, Anil K; Chuttani, Krishna; Aqil, Mohd; Ali, Asgar; Sultana, Yasmin

2014-02-15

The most important risk associated with glaucoma is the onset and progression of intraocular pressure. The objective of this study was to formulate in situ gel of chitosan nanoparticles to enhance the bioavailability and efficacy of dorzolamide in the glaucoma treatment. Optimized nanoparticles were spherical in shape (particle size: 164 nm) with a loading efficiency of 98.1%. The ex vivo release of the optimized in situ gel nanoparticle formulation showed a sustained drug release as compared to marketed formulation. The gamma scintigraphic study of prepared in situ nanoparticle gel showed good corneal retention compared to marketed formulation. HET-CAM assay of the prepared formulation scored 0.33 in 5 min which indicates the non-irritant property of the formulation. Thus in situ gel of dorzolamide hydrochloride loaded nanoparticles offers a more intensive treatment of glaucoma and a better patient compliance as it requires fewer applications per day compared to conventional eye drops. Copyright © 2013 Elsevier Ltd. All rights reserved.

Development of method of tritium labeling of pharmacological preparate of drotaverine hydrochloride (NOSPA)

International Nuclear Information System (INIS)

Kim, A.A.; Djuraeva, G.T.; Shukurov, B.V.

2004-01-01

Full text: The method for tritium labeling of pharmacological preparate of drotaverine hydrochloride (no spa) was developed. Drotaverine hydrochloride was labeled by thermally activated tritium in apparatus for tritium labeling. The optimum regime of labeling was selected. The system of purification of tritium labeled drotaverine hydrochloride by thin layer chromatography (TLC) has been developed. The TLC system of purification of tritium labeled drotaverine hydrochloride was developed. Tritium labeled preparation of drotaverine hydrochloride was purified by TLC on silicagel in system isopropanol: ammonia: water (8:1:1). We found appearance of additional fractions in tritium labeled preparation of drotaverine hydrochloride that testifies to partial transformation of drotaverine hydrochloride during procedure of labeling. Application of TLC for purification of tritium labeled preparation allows to purify completely drotaverine hydrochloride of by-products. The output of purified tritium labeled preparation of drotaverine hydrochloride was about 25 %. The received preparation had specific radioactivity - 3,2 MBq/mg, radiochemical purity of a preparation was 95 %. TLC purification seems inexpensive, fast and suitable for purification of tritium-labeled drotaverine hydrochloride. Thus developed method allows obtain tritium labeled preparation of drotaverine hydrochloride (no - spa), suitable for medical and biologic researches

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

Science.gov (United States)

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

2017-10-01

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

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

International Nuclear Information System (INIS)

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

2014-01-01

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

Interactions between chitosan and cells measured by AFM

Energy Technology Data Exchange (ETDEWEB)

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

2010-10-01

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

Interactions between chitosan and cells measured by AFM

International Nuclear Information System (INIS)

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

2010-01-01

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

Preparation of collagen peptide functionalized chitosan nanoparticles by ionic gelation method: An effective carrier system for encapsulation and release of doxorubicin for cancer drug delivery

Energy Technology Data Exchange (ETDEWEB)

Anandhakumar, S., E-mail: rsanandhakumar@gmail.com [SRM Research Institute, SRM University, Kattankulathur, Chennai 603203 (India); Krishnamoorthy, G.; Ramkumar, K.M. [SRM Research Institute, SRM University, Kattankulathur, Chennai 603203 (India); Raichur, A.M. [Department of Materials Engineering, Indian Institute of Science, Bangalore 560012 (India)

2017-01-01

In recent years, nanoparticles (NPs) based on biopolymers or peptides are gaining popularity for the encapsulation and release of drug molecules, especially for cancer therapy, due to their ability for targeted and controlled release. The use of collagen peptide (CP) for the preparation of chitosan (CN) NPs is especially interesting as it results in NPs that are stable under physiological conditions. In this work, mono-dispersed pH responsive CPCN NPs of about 100 nm were prepared via ionic gelation method by simple and mild co-precipitation of CN and CP. Investigation of NPs with Fourier transform infra-red (FTIR) spectroscopy and dynamic light scattering (DLS) measurements reveals that hydrogen bonding and electrostatic interactions are believed to be major driving forces for NP formation and drug encapsulation, respectively. Scanning electron microscopic (SEM) investigations show that hard and fine CPCN NPs transform to soft and bigger gel like particles as a function of collagen concentration. The unique “polymeric gel” structure of NPs showed high encapsulation efficiency towards doxorubicin hydrochloride (DOX) as well as pH controlled release. Anti-proliferative and cell viability analysis revealed that DOX loaded NPs showed excellent anti-proliferative characteristics against HeLa cells with favorable biocompatibility against normal cells. Such NPs have high potential for use as smart drug delivery carriers in advanced cancer therapy. - Highlights: • Preparation of collagen peptide functionalized chitosan nanoparticles • Hydrogen bonding plays a key role in particle formation. • Electrostatic interaction plays a key role in drug encapsulation. • Functionalized chitosan particles are more stable than chitosan NPs.

Efficient gene delivery using chitosan-polyethylenimine hybrid systems

Energy Technology Data Exchange (ETDEWEB)

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

2008-06-01

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

Efficient gene delivery using chitosan-polyethylenimine hybrid systems

International Nuclear Information System (INIS)

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

2008-01-01

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

Application of irradiated chitosan for fruit preservation

Energy Technology Data Exchange (ETDEWEB)

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

2000-09-01

Application of irradiated chitosan has been investigated for coating of fruit preservation. Anti-fungal activity of chitosan was induced by {gamma}-ray irradiation in dry condition at 25 kGy. The irradiated chitosan can suppress the growth of Aspergillus. spp. and Fusarium. spp. isolated from Vietnam mango. Fusarium. spp. was sensitive for irradiated chitosan than the other strains. The coating from irradiated chitosan solution at dose 31 kGy has prolonged the storage life of mango from 7 to 15 days. At the 15th day mango keeps good colour, natural ripening, without spoilage, weight loss 10%, whereas the control is spoiled completely and the sample of fruit with unirradiated chitosan coating could not ripe. The effect is due to the anti-fungal activity and change in physico-chemical properties of chitosan by irradiation. Radiation causes the decrease in viscosity affecting the gas permeability of coating film. The irradiated chitosan coating has positive effect on mango that is susceptible to chilling injury at low storage temperature. (author)

Plasticized chitosan/polyolefin films produced by extrusion.

Science.gov (United States)

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

2015-03-06

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

Application of irradiated chitosan for fruit preservation

International Nuclear Information System (INIS)

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

2000-01-01

Application of irradiated chitosan has been investigated for coating of fruit preservation. Anti-fungal activity of chitosan was induced by γ-ray irradiation in dry condition at 25 kGy. The irradiated chitosan can suppress the growth of Aspergillus. spp. and Fusarium. spp. isolated from Vietnam mango. Fusarium. spp. was sensitive for irradiated chitosan than the other strains. The coating from irradiated chitosan solution at dose 31 kGy has prolonged the storage life of mango from 7 to 15 days. At the 15th day mango keeps good colour, natural ripening, without spoilage, weight loss 10%, whereas the control is spoiled completely and the sample of fruit with unirradiated chitosan coating could not ripe. The effect is due to the anti-fungal activity and change in physico-chemical properties of chitosan by irradiation. Radiation causes the decrease in viscosity affecting the gas permeability of coating film. The irradiated chitosan coating has positive effect on mango that is susceptible to chilling injury at low storage temperature. (author)

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

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Fatemeh Roozbahani

2013-01-01

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

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

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Shete Amol S

2012-12-01

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

STIFFNESS MODIFICATION OF COTTON IN CHITOSAN TREATMENT

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CAMPOS Juan

2017-05-01

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

21 CFR 524.1982 - Proparacaine hydrochloride ophthalmic solution.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Proparacaine hydrochloride ophthalmic solution... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.1982 Proparacaine hydrochloride ophthalmic solution. (a) Specifications. The drug is...

Ionically crosslinked alginate–carboxymethyl cellulose beads for the delivery of protein therapeutics

International Nuclear Information System (INIS)

Kim, Min Sup; Park, Sang Jun; Gu, Bon Kang; Kim, Chun-Ho

2012-01-01

Highlights: ► We prepared Fe 3+ crosslinked alginate–carboxymethyl cellulose (AC) beads. ► Different surface and inner morphology of AC beads were observed on volume of CMC. ► AC beads showed minimum swelling degree in acidic condition. ► Protein release from AC beads was to control in gastrointestinal condition. - Abstract: We developed Fe 3+ -crosslinked alginate–carboxymethyl cellulose (AC) beads in various volume ratios by dropping an AC solution into a ferric chloride solution to form protein therapeutic carrier beads. Scanning electron microscopy revealed that the roughness and pore size of the crosslinked beads increased with the volume ratio of the carboxymethyl cellulose. Fourier transform-infrared analysis revealed the formation of a three-dimensional bonding structure between the anionic polymeric chains of AC and the Fe 3+ ions. The degree of swelling and the release profile of albumin from the beads were investigated under simulated gastrointestinal conditions (pH 1.2, 4.5, and 7.4). The Fe 3+ -crosslinked AC beads displayed different degrees of swelling and albumin release for the various AC volume ratios and under various pH conditions. An in vitro release test was used to monitor the controlled release of albumin from the AC beads under simulated gastrointestinal conditions over 24 h. The Fe 3+ -crosslinked AC beads protected and controlled the release of protein, demonstrating that such beads present a promising protein therapeutic carrier for the oral delivery.

Effect of Chitosan Properties on Immunoreactivity

Science.gov (United States)

Ravindranathan, Sruthi; Koppolu, Bhanu prasanth; Smith, Sean G.; Zaharoff, David A.

2016-01-01

Chitosan is a widely investigated biopolymer in drug and gene delivery, tissue engineering and vaccine development. However, the immune response to chitosan is not clearly understood due to contradicting results in literature regarding its immunoreactivity. Thus, in this study, we analyzed effects of various biochemical properties, namely degree of deacetylation (DDA), viscosity/polymer length and endotoxin levels, on immune responses by antigen presenting cells (APCs). Chitosan solutions from various sources were treated with mouse and human APCs (macrophages and/or dendritic cells) and the amount of tumor necrosis factor-α (TNF-α) released by the cells was used as an indicator of immunoreactivity. Our results indicate that only endotoxin content and not DDA or viscosity influenced chitosan-induced immune responses. Our data also indicate that low endotoxin chitosan (chitosan in preclinical studies in order for this valuable biomaterial to achieve widespread clinical application. PMID:27187416

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

Energy Technology Data Exchange (ETDEWEB)

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

2006-05-15

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

Effectiveness of chitosan against wine-related microorganisms.

Science.gov (United States)

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

2015-03-01

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

The Effect of Lithium Iodide to the Properties of Carboxymethyl κ-Carrageenan/Carboxymethyl Cellulose Polymer Electrolyte and Dye-Sensitized Solar Cell Performance

Directory of Open Access Journals (Sweden)

Siti Rudhziah Che Balian

2016-05-01

Full Text Available This study was undertaken to investigate the solid biopolymer electrolytes based on a carboxymethyl κ-carrageenan/carboxymethyl cellulose blend complexed with lithium iodide of various weight ratios. The complexation of the doping salt with the polymer blend was confirmed by Fourier transform infrared spectroscopy. Ionic conductivity of the film was determined by impedance spectroscopy in the frequency range of 10 Hz to 4 MHz and in the temperature range of 303–338 K. The ionic conductivity increased with the increase in lithium iodide concentration as well as temperature. The membrane comprising 30 wt % of lithium iodide was found to give the highest conductivity of 3.89 × 10−3 S·cm−1 at room temperature. The increase in conductivity was associated with the increase in the number as well as the mobility of the charge carries. The conductivity increase with temperature followed the Vogel–Tamman–Fulcher model. The fabricated dye-sensitive solar cell, FTO/TiO2-dye/CMKC/CMCE-LiI (30 wt % +I2/Pt exhibited the highest conversion efficiency of 0.11% at a light intensity of 100 mW·cm−2. This indicated that the biopolymer blend electrolyte system has potential for use in dye-sensitized solar cells.

Alkyl chitosan film-high strength, functional biomaterials.

Science.gov (United States)

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

2017-11-01

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

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

Science.gov (United States)

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

2017-08-09

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

Systematic analysis of trimazolin hydrochloride as adrenergic vasoconstrictor

Directory of Open Access Journals (Sweden)

Nikolić Goran

2008-01-01

Full Text Available Trimazolin-hydrochloride, which is used as a pharmaceutically active component (adrenergic vasoconstrictor for the production of decongestive preparations, was investigated in this paper by performing systematic analysis. In domestic and foreign pharmacopoeias, as well as in scientific and patent literature, there are no data on trimazolin and the methods of its investigation. Systematic analysis involves two investigation phases. A complete physicochemical characterization of the synthesized substance was done by previous investigation. In the second phase, a chemical structure of the synthesized pharmacologically active substance was confirmed to a certain degree of certainty by using the absorption spectroscopic methods (FTIR, UV-VIS, 1H-NMR. The spectroscopic methods used proved to be successful at identifying and investigating the purity of trimazolin hydrochloride. Liquid (RP-HPLC chromatography was used for the analysis of trimazolin hydrochloride in the nasal preparation (Adrianol. The method of titrimetric analysis was developed with the aim of quantitative determination of trimazolin hydrochloride in decongestive preparations.

Chitosan based metallic nanocomposite scaffolds as antimicrobial wound dressings.

Science.gov (United States)

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

2018-09-01

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

21 CFR 520.2345g - Tetracycline hydrochloride and sodium novobiocin tablets.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Tetracycline hydrochloride and sodium novobiocin... § 520.2345g Tetracycline hydrochloride and sodium novobiocin tablets. (a) Specifications. Each tablet contains the equivalent of 60 milligrams of tetracycline hydrochloride and 60 milligrams of novobiocin, or...

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

Science.gov (United States)

Lian, Ziru; Pan, Rong; Wang, Jiangtao

2016-11-01

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

RP-HPLC Estimation of Imipramine Hydrochloride and Diazepam in Tablets.

Science.gov (United States)

Srikantha, D; Raju, R R

2015-01-01

A simple and rapid reversed phase-high performance liquid chromatographic method was developed for simultaneous determination of imipramine hydrochloride and diazepam in pharmaceutical formulations. The elution was done in isocratic mode utilizing a mobile phase consisting of methanol:water:0.1M sodium acetate (30:50:20 v/v/v) on Chromosil C18 column with a flow rate of 1.0 ml/min and with detection at 243 nm. The measured retention time was 3.33±0.02 min for imipramine hydrochloride and 4.64±0.02 min for diazepam. Linearity was measured in the range 25-150 μg/ml for imipramine hydrochloride (r(2)=0.999) and in the range 5-30 μg/ml for diazepam (r(2)=0.9994), respectively. The limits of detection and quantitation were 0.03 and 0.1 μg/ml for imipramine hydrochloride and 0.02 and 0.07 μg/ml for diazepam. Satisfactory validation was also obtained from recovery (100.95-101.52% for imipramine hydrochloride and 99.47-100.33% for diazepam) studies, intraday and interday precision (hydrochloride and diazepam in tablets.

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

DEFF Research Database (Denmark)

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

2014-01-01

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

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

Directory of Open Access Journals (Sweden)

Abu Bakar Mohd Hilmi

2013-01-01

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

Physical Properties and Antibacterial Efficacy of Biodegradable Chitosan Films

OpenAIRE

中島, 照夫

2009-01-01

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

Green synthesis approach: extraction of chitosan from fungus mycelia.

Science.gov (United States)

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

2013-12-01

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

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

Science.gov (United States)

Başak, Esra; Aydemir, Tülin

2013-08-01

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

Degradation of chitosan for rice crops application

International Nuclear Information System (INIS)

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

2013-01-01

A variety of techniques including chemical and enzymatic hydrolysis, and radiation degradation processes can be used to prepare low molecular weight chitosan. Degradation of chitosan by radiation can be carried out in solid state and liquid state. Radiation degraded polysaccharides has been reported to exhibit growth-stimulating activity like phytohormones that induce the promotion in germination, shoot and root elongation in variety of plants. In this study, the chitosan was irradiated in solid state (powder form) by gamma rays within the dose range of 25-75 kGy. And the irradiated chitosan was then irradiated in solution form in the presence of hydrogen peroxide. The effects of irradiation on the molecular weight and viscosity of the chitosan were investigated using Ubbelohde Capillary Viscometer. The molecular weight and viscosity of the chitosan decreased with increment of absorbed doses. In the presence of hydrogen peroxide, the molecular weight of chitosan could be further decreased. The effect of radiation degraded chitosan on the growth promotion of rice was investigated and it was shown during seedling period of 15 days for transplanting whereby the growth is 15%-20% faster than using chemicals growth promoters. (authors)

Up-Scaling Production of Carboxymethyl Starch

International Nuclear Information System (INIS)

Mohd Hafiz Abdul Nasir; Zainon Othman; Kamaruddin Hashim; Siti Khadijah Abu Hadin; Nurul Nadia Shaaban

2015-01-01

Carboxymethyl starch (CMS) is a starch derivative formed by its reaction with sodium monochloroacetate which consist of OH-groups that are partially or completely replaced by ether substitution. Characteristic of CMSS defined by the degree of substitution (DS). DS is defined as the average number of substituents per anhydro glucose unit (AGU), the monomer unit of starch. The upgrading of CMSS production from 10L to 30L requires several experiments with different variable such as amount NaOH, amount of Sago Starch and reaction time. Each will give different DS. Quality control for the product cover moisture, viscosity and paste clarity. Therefore, SOP has been established to control the quality final product. (author)

Minocycline hydrochloride nanoliposomes inhibit the production of TNF-α in LPS-stimulated macrophages

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Liu D

2012-08-01

Full Text Available D Liu, P S YangShandong Provincial Key Laboratory of Oral Biomedicine, College of Stomatology, Shandong University, Shandong Province, People's Republic of ChinaBackground: As an adjunctive treatment of chronic periodontitis, it seems that the application of periocline or the other antimicrobials is effective against periodontopathogens. In this study, nanoliposomes were investigated as carriers of minocycline hydrochloride and the inhibition effects of minocycline hydrochloride nanoliposomes on the proliferation and lipopolysaccharide (LPS-stimulated production of tumor necrosis factor-α (TNF-α of macrophages were elucidated.Methods: After stimulation with 10 µg/mL LPS, murine macrophages (ANA-1 were treated with 10, 20, 40, 50 and 70 µg/mL 2% minocycline hydrochloride nanoliposomes, minocycline hydrochloride solution, and periocline for 6, 12, 24, 48 and 60 hours, respectively. A tetrazolium (MTT assay was used to evaluate macrophages cell proliferation rate and the levels of TNF-α mRNA were measured by SYBR Green Real Time PCR.Results: Ten to 70 µg/mL 2% minocycline hydrochloride nanoliposomes, minocycline hydrochloride solution, and periocline showed dose- and time-dependent inhibition of ANA-1 proliferation. Minocycline hydrochloride nanoliposomes showed dose- and ratio-dependent inhibition of LPS-stimulated TNF-α secretion of ANA-1. The inhibition effect of 10 µg/mL minocycline hydrochloride nanoliposomes was significantly better than that of two positive control groups, and equated to that of 60 or 70 µg/mL periocline. The expression of TNF-α mRNA in experimental group continued to reduce linearly with time.Conclusion: All three preparations of minocycline hydrochloride showed dose- and time-dependent inhibition of proliferation of ANA-1. Minocycline hydrochloride nanoliposomes have stronger and longer inhibition effect on LPS-stimulated TNF-α secretion of macrophages cell than minocycline hydrochloride solution and periocline

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-02-15

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

Developmental rates of immatures of three Chrysomya species (Diptera: Calliphoridae) under the effect of methylphenidate hydrochloride, phenobarbital, and methylphenidate hydrochloride associated with phenobarbital.

Science.gov (United States)

Rezende, Fábio; Alonso, Marcela A; Souza, Carina M; Thyssen, Patrícia J; Linhares, Arício X

2014-05-01

Entomotoxicology is focused on obtaining data on necrophagous entomofauna, for criminal investigations purposes. This study aimed to evaluate the effect of different concentrations of methylphenidate hydrochloride, phenobarbital, and their association on the developmental rate, larval and pupal survivorship, and the interval of emergence of adults of Chrysomya albiceps (Wiedemann), Chrysomya megacephala (Fabricius), and Chrysomya putoria (Wiedemann) (Diptera: Calliphoridae). Considering the therapeutic dose (TD) of methylphenidate hydrochloride (0.29 mg/Kg), the concentrations tested were 10× TD, 50× TD, and 100× TD. For phenobarbital, the concentrations used were 1× TD (=150 mg/Kg), 3.3× TD, and 6.7× TD. For the association of the drugs, the combinations used were 10× TD-methylphenidate hydrochloride plus 1× TD-phenobarbital, 50× TD-methylphenidate hydrochloride plus 3.3× TD-phenobarbital, and 100× TD-methylphenidate hydrochloride plus 6.7× TD-phenobarbital. The control group, without addition of drug, was maintained under the same conditions of temperature (25 ± 1 °C), humidity (70 ± 10%), and photoperiod (12 h). Specimens of each group were weighed every 12 h until pupariation. The developmental rate of the three Chrysomya species immatures was monitored. For C. albiceps the developmental time was delayed in 24 h for methylphenidate hydrochloride group and in 12 h for the phenobarbital and the drugs association groups. The effect was observed only at specific ages for C. megacephala, without altering the developmental time. For C. putoria, the developmental time was delayed in 12 h for methylphenidate hydrochloride group and in 24 h for the phenobarbital and the drugs association groups. The emergence interval was similar among all experimental groups, but larval and pupal viabilities were affected in different ways.

Preparation and characterization of water-absorbing composite ...

African Journals Online (AJOL)

The present work introduces a novel method for the formation of water absorbing composite membrane. The prepared composite is based on chitosan, carboxymethyl cellulose (CMC), and Montmorillonite. Prepared composite membrane exhibits high water absorbing and holding capacity with increasing clay content.

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

... nanoparticles prepared by co-precipitation and hydrothermal methods ... Chemically ordered face-centred tetragonal Fe–Pt nanoparticles embedded SiO2 films .... Synthesis and characterization of carboxymethyl chitosan hydrogel: .... Chemically deposited TiO2/CdS bilayer system for photoelectrochemical properties.

Effect of Chitosan Properties on Immunoreactivity

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Sruthi Ravindranathan

2016-05-01

Full Text Available Chitosan is a widely investigated biopolymer in drug and gene delivery, tissue engineering and vaccine development. However, the immune response to chitosan is not clearly understood due to contradicting results in literature regarding its immunoreactivity. Thus, in this study, we analyzed effects of various biochemical properties, namely degree of deacetylation (DDA, viscosity/polymer length and endotoxin levels, on immune responses by antigen presenting cells (APCs. Chitosan solutions from various sources were treated with mouse and human APCs (macrophages and/or dendritic cells and the amount of tumor necrosis factor-α (TNF-α released by the cells was used as an indicator of immunoreactivity. Our results indicate that only endotoxin content and not DDA or viscosity influenced chitosan-induced immune responses. Our data also indicate that low endotoxin chitosan (<0.01 EU/mg ranging from 20 to 600 cP and 80% to 97% DDA is essentially inert. This study emphasizes the need for more complete characterization and purification of chitosan in preclinical studies in order for this valuable biomaterial to achieve widespread clinical application.

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

Directory of Open Access Journals (Sweden)

Vanessa Tiemi Kimura

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

Effect of donepezil hydrochloride on normal-tension glaucoma

International Nuclear Information System (INIS)

Yoshida, Yukiko; Sugiyama, Tetsuya; Ikeda, Tsunehiko; Utsunomiya, Keita; Ogura, Yasuharu; Narabayashi, Isamu

2007-01-01

Peroral donepezil hydrochloride is claimed to be effective for Alzheimer disease, by elevating concentration of acetylcholine in the brain resulting in improved recognition and intracerebral circulation. It has been reported that some cases of normal-tension glaucoma (NTG) show cerebral circulation similar to patients of Alzheimer disease. The purpose of this study was to evaluate the effect of donepezil hydrochloride on NTG. This study was made on 10 eyes of 5 NTG patients who showed cerebral circulation similar to Alzheimer disease by 123 I-iofetamine (IMP) single photon emission computed tomography (SPECT). The series comprised 3 males and 2 females. Their age ranged from 64 to 79 years, average 69 years. They were given donepezil hydrochloride at the daily dosis of 5 mg for 6 months. Circulation in the optic nervehead was measured by laser speckle flowmetry. Circulation in the brain and optic nervehead significantly increased after 6 months of treatment. MD value by Humphrey tonometer improved in 5 eyes (50%). There was no change in intraocular pressure. Peroral donepezil hydrochloride may improve optic neuropathy in NTG through its neuroprotective action. (author)

Enhancement of antimicrobial activity of chitosan by irradiation

International Nuclear Information System (INIS)

Matsuhashi, S.; Kume, T.

1997-01-01

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

Radiation depolymerization of chitosan to prepare oligomers

International Nuclear Information System (INIS)

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

2003-01-01

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

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

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Nimet Bölgen

2016-08-01

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

21 CFR 524.1662b - Oxytetracycline hydrochloride, polymyxin B sulfate ophthalmic ointment.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride, polymyxin B sulfate... DOSAGE FORM NEW ANIMAL DRUGS § 524.1662b Oxytetracycline hydrochloride, polymyxin B sulfate ophthalmic ointment. (a) Specifications. Each gram of the ointment contains oxytetracycline hydrochloride equivalent...

Aging phenomena of chitosan and chitosan-diclofenac sodium system detected by low-frequency dielectric spectroscopy.

Science.gov (United States)

Bodek, K H; Bak, G W

1999-09-01

The use of natural polymers for design of dosage form has received considerable attention recently, especially from the safety point of view. Among these polymers, chitosan shows very interesting biological, chemical and physical properties which makes it possible to use chitosan for various pharmaceutical applications. Microcrystalline chitosan (MCCh) is a special multifunctional polymeric material existing in the form of either of gelatinous water dispersion or a powder. Thermal aging of chitosan and chitosan-diclofenac sodium mixture have been studied using low-frequency dielectric measurements. The aging was carried out by annealing in ambient atmosphere in the temperature range between 25 degrees C and 100 degrees C. The dielectric losses in the aged samples proved to decrease by about one order of magnitude. The additional measurements of molecular weight distribution and infrared absorption were also carried out for better understanding of nature of the ageing phenomena. Partial evacuation of water, cross-linking and improvement of structural order may be suggested to be a result of thermal aging of the investigated materials.

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

Science.gov (United States)

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

2013-08-14

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

Carboxymethyl starch mucoadhesive microspheres as gastroretentive dosage form.

Science.gov (United States)

Lemieux, Marc; Gosselin, Patrick; Mateescu, Mircea Alexandru

2015-12-30

Carboxymethyl starch microspheres (CMS-MS) were produced from carboxymethyl starch powder (CMS-P) with a degree of substitution (DS) from 0.1 to 1.5 in order to investigate the influence of DS on physicochemical, drug release and mucoadhesion properties as well as interactions with gastrointestinal tract (GIT) epithelial barrier models. Placebo and furosemide loaded CMS-MS were obtained by emulsion-crosslinking with sodium trimetaphosphate (STMP). DS had an impact on increasing equilibrium water uptake and modulating drug release properties of the CMS-MS according to the surrounding pH. The transepithelial electrical resistance (TEER) of NCI-N87 gastric cell monolayers was not influenced in presence of CMS-MS, whereas that of Caco-2 intestinal cell monolayers decreased with increasing DS but recovered initial values at about 15h post-treatment. CMS-MS with increasing DS also enhanced furosemide permeability across both NCI-N87 and Caco-2 monolayers at pH gradients from 3.0 to 7.4. Mucoadhesion of CMS-MS on gastric mucosa (acidic condition) increased with the DS up to 55% for a DS of 1.0 but decreased on neutral intestinal mucosa to less than 10% with DS of 0.1. The drug release, permeability enhancement and mucoadhesive properties of the CMS-MS suggest CMS-MS with DS between 0.6 and 1.0 as suitable excipient for gastroretentive oral delivery dosage forms. Copyright © 2015 Elsevier B.V. All rights reserved.

FORMULATION AND EVALUATION OF ISONIAZID AND ETHAMBUTOL HYDROCHLORIDE COMBINATION TABLETS

OpenAIRE

Margret Chandira R; Jayakar B; Palanisamy P.

2012-01-01

Ethambutol hydrochloride and Isoniazid Drugs are used as Antituberculosis agents. It is mainly used in the initial Treatment of pulmonary tuberculosis. Here in present study compressed tablet of Ethambutol hydrochloride and Isoniazid prepared by using HPMC, HPC, and PVPK -30 as binders. Compressed tablets of Ethambutol hydrochloride and Isoniazid were prepared by wet granulation method. Among different trials of F1 to F9 with wet granulation, the trial F1 showed satisfactory in-vitro drug re...

Electric field-assisted formation of organically modified hydroxyapatite (ormoHAP) spheres in carboxymethylated gelatin gels.

Science.gov (United States)

Heinemann, C; Heinemann, S; Kruppke, B; Worch, H; Thomas, J; Wiesmann, H P; Hanke, T

2016-10-15

A biomimetic strategy was developed in order to prepare organically modified hydroxyapatite (ormoHAP) with spherical shape. The technical approach is based on electric field-assisted migration of calcium ions and phosphate ions into a hydrogel composed of carboxymethylated gelatin. The electric field as well as the carboxymethylation using glucuronic acid (GlcA) significantly accelerates the mineralization process, which makes the process feasible for lab scale production of ormoHAP spheres and probably beyond. A further process was developed for gentle separation of the ormoHAP spheres from the gelatin gel without compromising the morphology of the mineral. The term ormoHAP was chosen since morphological analyses using electron microscopy (SEM, TEM) and element analysis (EDX, FT-IR, XRD) confirmed that carboxymethylated gelatin molecules use to act as organic templates for the formation of nanocrystalline HAP. The hydroxyapatite (HAP) crystals self-organize to form hollow spheres with diameters ranging from 100 to 500nm. The combination of the biocompatible chemical composition and the unique structure of the nanocomposites is considered to be a useful basis for future applications in functionalized degradable biomaterials. A novel bioinspired mineralization process was developed based on electric field-assisted migration of calcium and phosphate ions into biochemically carboxymethylated gelatin acting as organic template. Advantages over conventional hydroxyapatite include particle size distribution and homogeneity as well as achievable mechanical properties of relevant composites. Moreover, specifically developed calcium ion or phosphate ion release during degradation can be useful to adjust the fate of bone cells in order to manipulate remodeling processes. The hollow structure of the spheres can be useful for embedding drugs in the core, encapsulated by the highly mineralized outer shell. In this way, controlled drug release could be achieved, which enables

21 CFR 522.1222 - Ketamine hydrochloride injectable dosage forms.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ketamine hydrochloride injectable dosage forms. 522.1222 Section 522.1222 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... ANIMAL DRUGS § 522.1222 Ketamine hydrochloride injectable dosage forms. ...

Gelatin-carboxymethyl tamarind gum biocomposites: In vitro characterization & anti-inflammatory pharmacodynamics

Energy Technology Data Exchange (ETDEWEB)

Jana, Sougata, E-mail: janapharmacy@rediffmail.com; Banerjee, Abhisek; Sen, Kalyan Kumar; Maiti, Sabyasachi

2016-12-01

In this study, gelatin and carboxymethyl tamarind gum (CTG) were chemically cross-linked to control the delivery of aceclofenac from their interpenetrating network (IPNs). Infrared spectra, thermal and X-ray data supported that drug and polymer was compatible in the composite hydrogels. Irregularly shaped IPN microstructures were seen under field emission scanning electron microscope (FE-SEM). IPN system was capable of entrapping about 96% of the drug fed. CTG in IPN structures suppressed the drug release rate in HCl solution (pH 1.2); however extended the same in phosphate buffer solution (pH 6.8). The drug release was controlled by polymer chain relaxation/swelling and simple diffusion in vitro. The anti-inflammatory activity of drug-loaded biocomposites lasted over 7 h in albino rats, thus suggesting their potential as an anti-inflammatory therapeutics. - Highlights: • Novel gelatin-carboxymethyl tamarind gum biocomposites was synthesized. • FTIR, thermal and X-ray study ensured compatibility between drug and polymers. • FE-SEM image revealed irregular shape of the IPN microstructures. • In vivo anti-inflammatory pharmacodynamics in rat model was encouraging.

Green synthesis of silver nanoparticles using biopolymers, carboxymethylated-curdlan and fucoidan

International Nuclear Information System (INIS)

Leung, Thomas Chun-Yiu; Wong, Chung Kai; Xie Yong

2010-01-01

There is a growing need in developing a reliable and eco-friendly methodology for the synthesis of metallic nanoparticles, which may be applied for many nanotechnological applications. Natural compounds such as biopolymers are one of the resources which could be used for this purpose. The present study involves the development of a simple, ecological and user-friendly method in synthesizing silver nanoparticles by using carboxymethylated-curdlan or fucoidan as reducing and stabilizing agents. Reduction of silver ions by these biopolymers occurred when heating at 100 deg. C, led to the formation of silver nanoparticles in the range of 40-80 nm in dimensions. The silver nanoparticles were formed readily within 10-15 min. Morphological observation and characterization of the silver nanoparticles were performed by using dynamic light scattering (DLS), high-resolution transmission electron microscopy (HRTEM), and UV-vis absorption spectrophotometer. The size of silver nanoparticles can be controlled by using different concentrations of carboxymethylated-curdlan, fucoidan or silver nitrate. This way of silver nanoparticles preparation is easy, fast, user-friendly and suitable for large-scale production.

Human serum paraoxonase-1 (hPON1): in vitro inhibition effects of moxifloxacin hydrochloride, levofloxacin hemihidrate, cefepime hydrochloride, cefotaxime sodium and ceftizoxime sodium.

Science.gov (United States)

Türkeş, Cüneyt; Söyüt, Hakan; Beydemir, Şükrü

2015-01-01

In this study, we investigated the effects of antibacterial drugs (moxifloxacin hydrochloride, levofloxacin hemihidrate, cefepime hydrochloride, cefotaxime sodium and ceftizoxime sodium) on human serum paraoxonase-1 (hPON1) enzyme activity from human serum in vitro conditions. For this purpose, hPON1 enzyme was purified from human serum using simple chromatographic methods. The antibacterial drugs exhibited inhibitory effects on hPON1 at low concentrations. Ki constants were calculated to be 2.641 ± 0.040 mM, 5.525 ± 0.817 mM, 35.092 ± 1.093 mM, 252.762 ± 5.749 mM and 499.244 ± 10.149 mM, respectively. The inhibition mechanism of moxifloxacin hydrochloride was competitive, whereas levofloxacin hemihidrate, cefepime hydrochloride, cefotaxime sodium and ceftizoxime sodium were noncompetitive inhibitors.

Application of irradiated chitosan for fruit preservation

Energy Technology Data Exchange (ETDEWEB)

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

2000-03-01

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

Application of irradiated chitosan for fruit preservation

International Nuclear Information System (INIS)

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

2000-01-01

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

Preparation of alginate coated chitosan microparticles for vaccine delivery

Directory of Open Access Journals (Sweden)

Wei YuQuan

2008-11-01

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

Carboxymethyl guar gum nanoparticles for drug delivery applications: Preparation and preliminary in-vitro investigations

Energy Technology Data Exchange (ETDEWEB)

Dodi, G., E-mail: gianina.dodi@yahoo.co.uk [“Gheorghe Asachi” Technical University of Iasi (Romania); SCIENT — Research Centre for Instrumental Analysis, Bucharest (Romania); Pala, A. [University of Sassari, Sassari (Italy); Barbu, E. [University of Portsmouth, Portsmouth (United Kingdom); Peptanariu, D. [“Petru Poni” Institute of Macromolecular Chemistry, Iasi (Romania); Hritcu, D.; Popa, M.I. [“Gheorghe Asachi” Technical University of Iasi (Romania); Tamba, B.I. [“Gr. T. Popa” University of Medicine and Pharmacy, Iasi (Romania)

2016-06-01

Carboxymethyl guar gum (CMGG) synthesized from commercially available polysaccharide was formulated into nanoparticles via ionic gelation using trisodium trimetaphosphate (STMP) as cross-linking agent. Characterisation using a range of analytical techniques (FTIR, NMR, GPC, TGA and DLS) confirmed the CMGG structure and revealed the effect of the CMGG and STMP concentration on the main characteristics of the obtained nanoformulations. The average nanoparticle diameter was found to be around 208 nm, as determined by dynamic light scattering (DLS) and confirmed by scanning electron microscopy (SEM) and nanoparticle tracking analysis (NTA). Experiments using simulated gastric and intestinal fluids evidenced significant pH-dependent drug release behaviour of the nanoformulations loaded with Rhodamine B (RhB) as a model drug (loading capacity in excess of 83%), as monitored by UV–Vis. While dose-dependent cytotoxicity was observed, the nanoformulations appeared completely non-toxic at concentrations below 0.3 mg/mL. Results obtained so far suggest that carboxymethylated guar gum nanoparticles formulated with STMP warrant further investigations as polysaccharide based biocompatible drug nanocarriers. - Highlights: • Carboxymethyl guar gum nanoparticles preparation by ionic gelation • The optimum synthesis system designed particles around 200 nm • The nanoformulations appeared completely non-toxic at specific concentrations • The loaded formulations evidenced significant pH-dependent drug release behaviour • The results encourage further investigations as polysaccharidic drug nanocarriers.

Carboxymethyl guar gum nanoparticles for drug delivery applications: Preparation and preliminary in-vitro investigations

International Nuclear Information System (INIS)

Dodi, G.; Pala, A.; Barbu, E.; Peptanariu, D.; Hritcu, D.; Popa, M.I.; Tamba, B.I.

2016-01-01

Carboxymethyl guar gum (CMGG) synthesized from commercially available polysaccharide was formulated into nanoparticles via ionic gelation using trisodium trimetaphosphate (STMP) as cross-linking agent. Characterisation using a range of analytical techniques (FTIR, NMR, GPC, TGA and DLS) confirmed the CMGG structure and revealed the effect of the CMGG and STMP concentration on the main characteristics of the obtained nanoformulations. The average nanoparticle diameter was found to be around 208 nm, as determined by dynamic light scattering (DLS) and confirmed by scanning electron microscopy (SEM) and nanoparticle tracking analysis (NTA). Experiments using simulated gastric and intestinal fluids evidenced significant pH-dependent drug release behaviour of the nanoformulations loaded with Rhodamine B (RhB) as a model drug (loading capacity in excess of 83%), as monitored by UV–Vis. While dose-dependent cytotoxicity was observed, the nanoformulations appeared completely non-toxic at concentrations below 0.3 mg/mL. Results obtained so far suggest that carboxymethylated guar gum nanoparticles formulated with STMP warrant further investigations as polysaccharide based biocompatible drug nanocarriers. - Highlights: • Carboxymethyl guar gum nanoparticles preparation by ionic gelation • The optimum synthesis system designed particles around 200 nm • The nanoformulations appeared completely non-toxic at specific concentrations • The loaded formulations evidenced significant pH-dependent drug release behaviour • The results encourage further investigations as polysaccharidic drug nanocarriers

COMPARATIVE STUDIES OF IMMUNOMODULATING PROPERTIES OF C HITOSAN AND ITS DERIVATIVES

Directory of Open Access Journals (Sweden)

L. A. Ivanushko

2007-01-01

Full Text Available Abstract. Comparative study was carried out, aiming to assess immunostimulatory properties of high-molecular chitosan (Ch-HM and its derivatives, i.e., low molecular weight chitosan (Ch-LM, N-3-hydroxymyristoyl (Ch-LM at a low acylation ratio, N-3-hydroxymyristoylchitooligosaccharides (N-acylchito-biose, -triose, -tetraose, N-, O-carboxyalkylchitosans (carboxymethyl, -ethyl, -propyl derivates. It was established, that the chemical modifications of chitosan influenced its biological activity. The derivatives of chitosan were found to have improved physical properties (good solubility in neutral and alkaline solutions, low viscosity in acidic solutions, good absorption from a gastrointestinal compartment, as compared with initial (high molecular weight chitosan formula. They possess immunomodulatory properties and may be regarded as promising substances for preparation of medical drugs and biologically active food additives (BAFA.

Chitosan-nanosilica hybrid materials: Preparation and properties

International Nuclear Information System (INIS)

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

2014-01-01

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

Chitosan-nanosilica hybrid materials: Preparation and properties

Energy Technology Data Exchange (ETDEWEB)

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

2014-11-30

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

DAU HUNG ANH

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science. DAU HUNG ANH. Articles written in Bulletin of Materials Science. Volume 40 Issue 6 October 2017 pp 1189-1196. Facile fabrication of organobentonite–carboxymethyl chitosan hybrid film that absorbs organophosphate insecticides · DAU HUNG ANH KANCHANA DUMRI.

Preparation and characterization of water-absorbing composite ...

African Journals Online (AJOL)

ABCO

2012-08-16

Aug 16, 2012 ... The present work introduces a novel method for the formation of water absorbing composite membrane. The prepared composite is based on chitosan, carboxymethyl cellulose (CMC), and. Montmorillonite. Prepared composite membrane exhibits high water absorbing and holding capacity with increasing ...

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

Science.gov (United States)

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

Fundamentals of ionic conductivity relaxation gained from study of procaine hydrochloride and procainamide hydrochloride at ambient and elevated pressure.

Science.gov (United States)

Wojnarowska, Z; Swiety-Pospiech, A; Grzybowska, K; Hawelek, L; Paluch, M; Ngai, K L

2012-04-28

The pharmaceuticals, procaine hydrochloride and procainamide hydrochloride, are glass-forming as well as ionically conducting materials. We have made dielectric measurements at ambient and elevated pressures to characterize the dynamics of the ion conductivity relaxation in these pharmaceuticals, and calorimetric measurements for the structural relaxation. Perhaps due to their special chemical and physical structures, novel features are found in the ionic conductivity relaxation of these pharmaceuticals. Data of conductivity relaxation in most ionic conductors when represented by the electric loss modulus usually show a single resolved peak in the electric modulus loss M(")(f) spectra. However, in procaine hydrochloride and procainamide hydrochloride we find in addition another resolved loss peak at higher frequencies over a temperature range spanning across T(g). The situation is analogous to many non-ionic glass-formers showing the presence of the structural α-relaxation together with the Johari-Goldstein (JG) β-relaxation. Naturally the analogy leads us to name the slower and faster processes resolved in procaine hydrochloride and procainamide hydrochloride as the primary α-conductivity relaxation and the secondary β-conductivity relaxation, respectively. The analogy of the β-conductivity relaxation in procaine HCl and procainamide HCl with JG β-relaxation in non-ionic glass-formers goes further by the finding that the β-conductivity is strongly related to the α-conductivity relaxation at temperatures above and below T(g). At elevated pressure but compensated by raising temperature to maintain α-conductivity relaxation time constant, the data show invariance of the ratio between the β- and the α-conductivity relaxation times to changes of thermodynamic condition. This property indicates that the β-conductivity relaxation has fundamental importance and is indispensable as the precursor of the α-conductivity relaxation, analogous to the relation found

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

Directory of Open Access Journals (Sweden)

2011-04-01

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

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

Science.gov (United States)

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

2016-12-01

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

Maillard reaction products from chitosan-xylan ionic liquid solution.

Science.gov (United States)

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

2013-10-15

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

Chitosan: A potential biopolymer for wound management.

Science.gov (United States)

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

2017-09-01

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

Molecular interactions in gelatin/chitosan composite films.

Science.gov (United States)

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

2017-11-15

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

Suppression of Zn stress on barley by irradiated chitosan

Energy Technology Data Exchange (ETDEWEB)

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

2001-03-01

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

Chitosan Fibers Modified with HAp/β–TCP Nanoparticles

Directory of Open Access Journals (Sweden)

Dariusz Wawro

2011-10-01

Full Text Available This paper describes a method for preparing chitosan fibers modified with hydroxyapatite (HAp, tricalcium phosphate (β-TCP, and HAp/β-TCP nanoparticles. Fiber-grade chitosan derived from the northern shrimp (Pandalus borealis and nanoparticles of tricalcium phosphate (β-TCP and hydroxyapatite (HAp suspended in a diluted chitosan solution were used in the investigation. Diluted chitosan solution containing nanoparticles of Hap/β-TCP was introduced to a 5.16 wt% solution of chitosan in 3.0 wt% acetic acid. The properties of the spinning solutions were examined. Chitosan fibers modified with nanoparticles of HAp/β-TCP were characterized by a level of tenacity and calcium content one hundred times higher than that of regular chitosan fibers.

Suppression of Zn stress on barley by irradiated chitosan

International Nuclear Information System (INIS)

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

2001-01-01

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

Electrochemical and Thermal Studies of Prepared Conducting Chitosan Biopolymer Film

International Nuclear Information System (INIS)

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

2005-09-01

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

Some features of irradiated chitosan and its biological effect

International Nuclear Information System (INIS)

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

2001-01-01

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

Chitosan dan Aplikasi Klinisnya Sebagai Biomaterial

Directory of Open Access Journals (Sweden)

Bambang Irawan

2015-10-01

Full Text Available The development of new materials with both organic and inorganic structures is of great interest to obtain special material properties. Chitosan [2-amino-2-deoxy-D-glucan] can be obtained by N-deacetylation of chitin. Chitin is the second most abundant biopolymer in nature and the supporting material of crustaceans, insects, fungi etc. Chitosan is unique polysaccharide and has been widely used in various biomedical application due to its biocompatibility, low toxicity, biodegradability, non-immunogenic and non-carcinogenic character. In the past few years, chitosan and some of its modifications have been reported for use in biomedical applications such as artificial skin, wound dressing, anticoagulant, suture, drug delivery, vaccine carrier and dietary fibers. Recently, the use of chitosan and its derivatives has received much attention as temporary scaffolding to promotie mineralization or stimulate endochodral ossification. This article aims to give a broad overview of chitosan and its clinical applications as biomaterial.

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

International Nuclear Information System (INIS)

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

2002-01-01

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

Determination of the Optimum Conditions for Production of Chitosan Nanoparticles

Directory of Open Access Journals (Sweden)

A. Dustgani

2007-12-01

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

Chitosan Based Self-Assembled Nanoparticles in Drug Delivery

Directory of Open Access Journals (Sweden)

Javier Pérez Quiñones

2018-02-01

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

3D Bioprinting of Carboxymethylated-Periodate Oxidized Nanocellulose Constructs for Wound Dressing Applications.

Science.gov (United States)

Rees, Adam; Powell, Lydia C; Chinga-Carrasco, Gary; Gethin, David T; Syverud, Kristin; Hill, Katja E; Thomas, David W

2015-01-01

Nanocellulose has a variety of advantages, which make the material most suitable for use in biomedical devices such as wound dressings. The material is strong, allows for production of transparent films, provides a moist wound healing environment, and can form elastic gels with bioresponsive characteristics. In this study, we explore the application of nanocellulose as a bioink for modifying film surfaces by a bioprinting process. Two different nanocelluloses were used, prepared with TEMPO mediated oxidation and a combination of carboxymethylation and periodate oxidation. The combination of carboxymethylation and periodate oxidation produced a homogeneous material with short nanofibrils, having widths material with good rheological properties for use as a bioink. The nanocellulose bioink was thus used for printing 3D porous structures, which is exemplified in this study. We also demonstrated that both nanocelluloses did not support bacterial growth, which is an interesting property of these novel materials.

Some features of irradiated chitosan and its biological effect

Energy Technology Data Exchange (ETDEWEB)

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

2001-03-01

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

Physicochemical characterization and evaluation of buccal adhesive patches containing propranolol hydrochloride.

Science.gov (United States)

Patel, V M; Prajapati, B G; Patel, J K; Patel, M M

2006-07-01

Buccal adhesive patches containing 20 mg of propranolol hydrochloride were prepared using solvent casting method. Chitosan was used as a natural bioadhesive polymer. Patches were prepared at different ratios of PVP K-30 and evaluated for various physicochemical characteristics such as weight variation, drug content uniformity, folding endurance, surface pH, ex-vivo mucoadhesive strength, ex-vivo residence time, in vitro drug release and in vitro buccal permeation study. Patches exhibited sustained release over a period of 7 hours. The mechanism of drug release was found to be Non-Fickian diffusion. Addition of PVP K-30 generally enhanced the releasing rate. The ex-vivo mucoadhesive strength was performed using sheep buccal mucosa on modified physical balance. Optimized patches (batch F4) showed satisfactory bioadhesive strength (9.6 degrees 2.0 gram) and ex vivo residence time (272 degrees 0.25 minutes). Swelling index was proportional to PVP K-30. The surface pH of all batches was within satisfactory limit (7.0+/-1.5) and hence patches would not cause irritation in the buccal cavity. Good correlation was observed between in vitro drug release and in vitro drug permeation with correlation coefficient of 0.9364. Stability of optimized patches was performed in natural human saliva showed that both drug and dosage forms were stable in human saliva.

Degree of Acetylization Chitosan Gonggong Snail Shells

Science.gov (United States)

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

2018-04-01

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

Chitosan pretreatment for cotton dyeing with black tea

Science.gov (United States)

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

2017-10-01

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

Synthesis of novel cellulose- based antibacterial composites of Ag nanoparticles@ metal-organic frameworks@ carboxymethylated fibers.

Science.gov (United States)

Duan, Chao; Meng, Jingru; Wang, Xinqi; Meng, Xin; Sun, Xiaole; Xu, Yongjian; Zhao, Wei; Ni, Yonghao

2018-08-01

A novel cellulose-based antibacterial material, namely silver nanoparticles@ metal-organic frameworks@ carboxymethylated fibers composites (Ag NPs@ HKUST-1@ CFs), was synthesized. The results showed that the metal-organic frameworks (HKUST-1) were uniformly anchored on the fiber's surfaces by virtue of complexation between copper ions in HKUST-1 and carboxyl groups on the carboxymethylated fibers (CFs). The silver nanoparticles (Ag NPs) were immobilized and well-dispersed into the pores and/or onto the surfaces of HKUST-1 via in situ microwave reduction, resulting in the formation of novel Ag NPs@ HKUST-1@ CFs composites. The antibacterial assays showed that the as-prepared composites exhibited a much higher antibacterial activity than Ag NPs@ CFs or HKUST-1@ CFs samples. Copyright © 2018 Elsevier Ltd. All rights reserved.

Targeted quantification of N-1-(carboxymethyl) valine and N-1-(carboxyethyl) valine peptides of ?-hemoglobin for better diagnostics in diabetes

OpenAIRE

Jagadeeshaprasad, Mashanipalya G.; Batkulwar, Kedar B.; Meshram, Nishita N.; Tiwari, Shalbha; Korwar, Arvind M.; Unnikrishnan, Ambika G.; Kulkarni, Mahesh J.

2016-01-01

Background N-1-(Deoxyfructosyl) valine (DFV) ?-hemoglobin (?-Hb), commonly referred as HbA1c, is widely used diagnostic marker in diabetes, believed to provide glycemic status of preceding 90?120?days. However, the turnover of hemoglobin is about 120?days, the DFV-?-Hb, an early and reversible glycation product eventually may undergo irreversible advanced glycation modifications such as carboxymethylation or carboxyethylation. Hence quantification of N-1-(carboxymethyl) valine (CMV) and N-1-(...

Degradation of chitosan-based materials after different sterilization treatments

International Nuclear Information System (INIS)

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

2012-01-01

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

Humidity detection using chitosan film based sensor

Science.gov (United States)

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

2018-02-01

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

Formulation and evaluation of tramadol hydrochloride rectal suppositories

OpenAIRE

Saleem M; Taher M; Sanaullah S; Najmuddin M; Ali Javed; Humaira S; Roshan S

2008-01-01

Rectal suppositories of tramadol hydrochloride were prepared using different bases and polymers like PEG, cocoa butter, agar and the effect of different additives on in vitro release of tramadol hydrochloride was studied. The agar-based suppositories were non-disintegrating/non-dissolving, whereas PEGs were disintegrating/dissolving and cocoa butter were melting suppositories. All the prepared suppositories were evaluated for various physical parameters like weight variation, drug content a...

An Investigation of Chitosan for Sorption of Radionuclides

Science.gov (United States)

2012-06-05

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

Effects of sulfate chitosan derivatives on nonalcoholic fatty liver disease

Science.gov (United States)

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

2014-06-01

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

Effect of chitosan coatings on postharvest green asparagus quality.

Science.gov (United States)

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

2013-02-15

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

Interaction between chitosan and its related enzymes: A review.

Science.gov (United States)

Shinya, Shoko; Fukamizo, Tamo

2017-11-01

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

β-Chitin and chitosan from squid gladius: Biological activities of chitosan and its application as clarifying agent for apple juice.

Science.gov (United States)

Abdelmalek, Baha Eddine; Sila, Assaâd; Haddar, Anissa; Bougatef, Ali; Ayadi, Mohamed Ali

2017-11-01

Chitin is the second most abundant polysaccharide in biomass after cellulose and the term chitosan usually refers to a family of polymers obtained after chitin deacetylation. The aim of this work was the preparation and the characterization of chitin and chitosan from the gladius (pen) of the European squid (Loligo vulgaris). A high level of deproteinization (more than 80%) was recorded using Alcalase ® with an enzyme/protein ratio of 10U/mg. The demineralization of the gladius was completely achieved within 8h at room temperature in HCl. 13 C NMR, FTIR, and XRD diffractograms of prepared chitin and chitosan were taken and then degree of deacetylation of chitosan was calculated using 13 C CP/MAS-NMR Spectroscopic. Further, in vitro antioxidant capacity of chitosan was evaluated on 1,1-diphenyl-2-picrylhydrazyl method (IC 50 =3.2mgmL -1 ) and the β-carotene bleaching assay (IC 50 =3.3mgmL -1 ). Antimicrobial activity was also investigated and assays indicated that prepared chitosan exhibited marked inhibitory activity against all microbial strains tested. Additionally, chitosan was tested such as clarifying agent for apple juice and showed powerful clarification capability, without affecting nutritional value. Furthermore, the results suggested that prepared chitosan could be used as alternative additive in pharmaceutical preparations and food industry. Copyright © 2017 Elsevier B.V. All rights reserved.

Poly(acrylonitrile)chitosan composite membranes for urease immobilization.

Science.gov (United States)

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

2007-05-10

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

Emerging Chitosan-Based Films for Food Packaging Applications.

Science.gov (United States)

Wang, Hongxia; Qian, Jun; Ding, Fuyuan

2018-01-17

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

Lipase entrapment in PVA/Chitosan biodegradable film for reactor coatings

Energy Technology Data Exchange (ETDEWEB)

Batista, Karla A. [Departamento de Bioquímica e Biologia Molecular, Laboratório de Química de Proteínas, Universidade Federal de Goiás, Cx. Postal 131, 74001-970, Goiânia, GO (Brazil); Lopes, Flavio Marques [Departamento de Bioquímica e Biologia Molecular, Laboratório de Química de Proteínas, Universidade Federal de Goiás, Cx. Postal 131, 74001-970, Goiânia, GO (Brazil); Unidade Universitária de Ciências Exatas e Tecnológicas, Universidade Estadual de Goiás, Anápolis, GO (Brazil); Yamashita, Fabio [Departamento de Tecnologia de Alimentos e Medicamentos, Laboratório de Tecnologia, Universidade Estadual de Londrina, Cx. Postal 6001, CEP 86051-990, Londrina, PR (Brazil); Fernandes, Kátia Flávia, E-mail: katia@icb.ufg.br [Departamento de Bioquímica e Biologia Molecular, Laboratório de Química de Proteínas, Universidade Federal de Goiás, Cx. Postal 131, 74001-970, Goiânia, GO (Brazil)

2013-04-01

This study reports the development and characterization of novel biodegradable film, based on chitosan and polyvinyl alcohol containing lipase entrapped. The films showed a thickness of 70.4 and 79 μm to PVA/Chitosan and PVA/Chitosan/Lipase, respectively. The entrapment of lipase in PVA/Chitosan film resulted in increasing of 69.4% tensile strength (TS), and 52.4% of elongation. SEM images showed the formation of a continuous film, without pores or cracks. The lipase entrapment efficiency was estimated in 92% and the films were repeatedly used for 25 hydrolytic cycles, maintaining 62% of initial activity. The PVA/Chitosan/Lipase film was used for olive oil hydrolysis of high performance. These results indicate that PVA/Chitosan/Lipase is a promising material for biotechnology applications such as triacylglycerol hydrolysis and biodiesel production. - Highlights: ► Development and characterization of PVA/Chitosan biodegradable film ► Lipase immobilization onto PVA/Chitosan film ► PVA/Chitosan/Lipase film for reactor coating ► Olive oil hydrolysis using PVA/Chitosan/Lipase film.

Lipase entrapment in PVA/Chitosan biodegradable film for reactor coatings

International Nuclear Information System (INIS)

Batista, Karla A.; Lopes, Flavio Marques; Yamashita, Fabio; Fernandes, Kátia Flávia

2013-01-01

This study reports the development and characterization of novel biodegradable film, based on chitosan and polyvinyl alcohol containing lipase entrapped. The films showed a thickness of 70.4 and 79 μm to PVA/Chitosan and PVA/Chitosan/Lipase, respectively. The entrapment of lipase in PVA/Chitosan film resulted in increasing of 69.4% tensile strength (TS), and 52.4% of elongation. SEM images showed the formation of a continuous film, without pores or cracks. The lipase entrapment efficiency was estimated in 92% and the films were repeatedly used for 25 hydrolytic cycles, maintaining 62% of initial activity. The PVA/Chitosan/Lipase film was used for olive oil hydrolysis of high performance. These results indicate that PVA/Chitosan/Lipase is a promising material for biotechnology applications such as triacylglycerol hydrolysis and biodiesel production. - Highlights: ► Development and characterization of PVA/Chitosan biodegradable film ► Lipase immobilization onto PVA/Chitosan film ► PVA/Chitosan/Lipase film for reactor coating ► Olive oil hydrolysis using PVA/Chitosan/Lipase film

Grape Preservation Using Chitosan Combined with β-Cyclodextrin

Directory of Open Access Journals (Sweden)

Yu Youwei

2013-01-01

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

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

NARCIS (Netherlands)

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

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

Effect of degree of deacetylation of chitosan on adsorption capacity and reusability of chitosan/polyvinyl alcohol/TiO2 nano composite.

Science.gov (United States)

Habiba, Umma; Joo, Tan Chin; Siddique, Tawsif A; Salleh, Areisman; Ang, Bee Chin; Afifi, Amalina M

2017-11-01

The chitosan/polyvinyl alcohol/TiO 2 composite was synthesized. Two different degrees of deacetylation of chitosan were prepared by hydrolysis to compare the effectiveness of them. The composite was analyzed via field emission scanning electron microscopy, Fourier transform infrared, X-ray diffraction, thermal gravimetric analysis, weight loss test and adsorption study. The FTIR and XRD results proved the interaction among chitosan, PVA and TiO 2 without any chemical reaction. It was found that, chitosan with higher degree of deacetylation has better stability. Furthermore, it also showed that higher DD of chitosan required less time to reach equilibrium for methyl orange. The adsorption followed the pseudo-second-order kinetic model. The Langmuir and Freundlich isotherm models were fitted well for isotherm study. Adsorption capacity was higher for the composite containing chitosan with higher DD. The dye removal rate was independent of the dye's initial concentration. The adsorption capacity was increased with temperature and it was found from reusability test that the composite containing chitosan with higher DD is more reusable. It was notable that adsorption capacity was even after 15 runs. Therefore, chitosan/PVA/TiO 2 composite can be a very useful material for dye removal. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization of a single-isomer carboxymethyl-beta-cyclodextrin in chiral capillary electrophoresis.

Science.gov (United States)

Fejős, Ida; Varga, Erzsébet; Benkovics, Gábor; Malanga, Milo; Sohajda, Tamás; Szemán, Julianna; Béni, Szabolcs

2017-08-01

In this work, the synthesis, characterization, and chiral capillary electrophoretic study of heptakis-(2,3-di-O-methyl-6-O-carboxymethyl)-β-CD (HDMCM), a single-isomer carboxymethylated CD, are presented. The pH-dependent and selector concentration-dependent enantiorecognition properties of HDMCM were investigated and discussed herein. The enantioseparation was assessed applying a structurally diverse set of noncharged, basic, and zwitterionic racemates. The increase in the selector concentration and gross negative charge of HDMCM improved the enantioseparation that could be observed in the majority of the cases. HDMCM was also successfully applied as BGE additive in NACE using a methanol-based system in order to prove the separation selectivity features and to highlight the broad applicability of HDMCM. Over 25 racemates showed partial or baseline separation with HDMCM under the conditions investigated, among which optimal enantiomer migration order was found for the four stereoisomers of tadalafil, tapentadol, and dapoxetine, offering the possibility of a chiral CE method development for chiral purity profiling of these drugs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis and characterization of carboxymethyl cellulose from office waste paper: A greener approach towards waste management

International Nuclear Information System (INIS)

Joshi, Gyanesh; Naithani, Sanjay; Varshney, V.K.; Bisht, Surendra S.; Rana, Vikas; Gupta, P.K.

2015-01-01

Highlights: • Carboxymethyl cellulose (CMC) was successfully prepared from waste paper. • CMC had maximum degree of substitution (DS) 1.07. • Rheological studies of CMC (DS, 1.07) showed non-Newtonian pseudoplastic behavior. • Characterization of CMC was done by FT-IR and NMR techniques. • Morphology of prepared CMC was studied by SEM. - Abstract: In the present study, functionalization of mixed office waste (MOW) paper has been carried out to synthesize carboxymethyl cellulose, a most widely used product for various applications. MOW was pulped and deinked prior to carboxymethylation. The deinked pulp yield was 80.62 ± 2.0% with 72.30 ± 1.50% deinkability factor. The deinked pulp was converted to CMC by alkalization followed by etherification using NaOH and ClCH 2 COONa respectively, in an alcoholic medium. Maximum degree of substitution (DS) (1.07) of prepared CMC was achieved at 50 °C with 0.094 M and 0.108 M concentrations of NaOH and ClCH 2 COONa respectively for 3 h reaction time. The rheological characteristics of 1–3% aqueous solution of optimized CMC product showed the non-Newtonian pseudoplastic behavior. Fourier transform infra red (FTIR), nuclear magnetic resonance (NMR) and scanning electron microscope (SEM) study were used to characterize the CMC product

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

International Nuclear Information System (INIS)

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

1997-01-01

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

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

International Nuclear Information System (INIS)

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

2014-01-01

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

nanocomposites chitosan /clay for electrochemical sensors

International Nuclear Information System (INIS)

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

2009-01-01

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

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

Science.gov (United States)

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

2017-07-24

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

Use of the montmorillonite as crosslink agents for chitosan

International Nuclear Information System (INIS)

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

2009-01-01

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

Enhancement of Antibacterial activity of Chitosan by gamma irradiation

International Nuclear Information System (INIS)

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

2006-01-01

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

Thiolated chitosans: useful excipients for oral drug delivery.

Science.gov (United States)

Werle, Martin; Bernkop-Schnürch, Andreas

2008-03-01

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

Effect of carboxymethyl cellulose and ionic strength on stability of mineral suspensions in potash ore flotation systems.

Science.gov (United States)

Pawlik, M; Laskowski, J S; Ansari, A

2003-04-15

The adsorption of sodium carboxymethyl cellulose from aqueous solutions varying in ionic strength from that of distilled water to 50% NaCl/KCl brine (about 3.5 mol/dm(3)) onto illite and dolomite has been studied. The purpose of this work was to investigate the solvency effects in the phenomena underlying the potash flotation process that is carried out in saturated brine. Based on viscosity measurements, the adsorption results were analyzed in terms of a simple model of polymer macromolecules in solution. Suspension stability measurements carried out concomitantly with adsorption tests showed the ranges of carboxymethyl cellulose concentration over which the tested suspensions either were aggregated or were restabilized.

Synthesize and Characterization of Hydroxypropyl-N-octanealkyl Chitosan Ramification

Science.gov (United States)

Tan, Fu-neng

2018-03-01

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

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

Science.gov (United States)

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

2011-01-10

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

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

Science.gov (United States)

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

2016-11-01

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

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

Science.gov (United States)

Jarmila, Vinsová; Vavríková, Eva

2011-01-01

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

Phytase-mediated enzymatic mineralization of chitosan-enriched hydrogels

DEFF Research Database (Denmark)

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

2018-01-01

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

S-Adenosyl-S-carboxymethyl-l-homocysteine: a novel cofactor found in the putative tRNA-modifying enzyme CmoA

International Nuclear Information System (INIS)

Byrne, Robert T.; Whelan, Fiona; Aller, Pierre; Bird, Louise E.; Dowle, Adam; Lobley, Carina M. C.; Reddivari, Yamini; Nettleship, Joanne E.; Owens, Raymond J.; Antson, Alfred A.; Waterman, David G.

2013-01-01

The putative methyltransferase CmoA is involved in the nucleoside modification of transfer RNA. X-ray crystallography and mass spectrometry are used to show that it contains a novel SAM derivative, S-adenosyl-S-carboxymethyl-l-homocysteine, in which the donor methyl group is replaced by a carboxymethyl group. Uridine at position 34 of bacterial transfer RNAs is commonly modified to uridine-5-oxyacetic acid (cmo 5 U) to increase the decoding capacity. The protein CmoA is involved in the formation of cmo 5 U and was annotated as an S-adenosyl-l-methionine-dependent (SAM-dependent) methyltransferase on the basis of its sequence homology to other SAM-containing enzymes. However, both the crystal structure of Escherichia coli CmoA at 1.73 Å resolution and mass spectrometry demonstrate that it contains a novel cofactor, S-adenosyl-S-carboxymethyl-l-homocysteine (SCM-SAH), in which the donor methyl group is substituted by a carboxymethyl group. The carboxyl moiety forms a salt-bridge interaction with Arg199 that is conserved in a large group of CmoA-related proteins but is not conserved in other SAM-containing enzymes. This raises the possibility that a number of enzymes that have previously been annotated as SAM-dependent are in fact SCM-SAH-dependent. Indeed, inspection of electron density for one such enzyme with known X-ray structure, PDB entry http://scripts.iucr.org/cgi-bin/cr.cgi?rm, suggests that the active site contains SCM-SAH and not SAM

Floating Microparticulate Oral Diltiazem Hydrochloride Delivery ...

African Journals Online (AJOL)

Delivery System for Improved Delivery to Heart ... Conclusion: Microparticulate floating (gastroretentive) oral drug delivery system of diltiazem prepared ..... treatment of cardiac disease. ... hydrochloride-loaded mucoadhesive microspheres.

Preparation and characterization of magnetic chitosan particles for hyperthermia application

International Nuclear Information System (INIS)

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

2005-01-01

The size and shape of magnetic chitosan particles were found to be dependent on both the barium ferrite/chitosan (BF/C) ratio and viscosity of a chitosan solution. The saturation magnetization of magnetic chitosan particles varied directly with the BF/C ratio, while coercivity remained almost constant. Notably, incorporated chitosan was shown to exert substantial activity with regard to low cytotoxicity and high heating rate

Rheological study of chitosan in solution

International Nuclear Information System (INIS)

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

2009-01-01

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

Chitosan in Mucoadhesive Drug Delivery: Focus on Local Vaginal Therapy

Directory of Open Access Journals (Sweden)

Toril Andersen

2015-01-01

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

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

Science.gov (United States)

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

2008-07-01

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

Omics for Investigating Chitosan as an Antifungal and Gene Modulator

Directory of Open Access Journals (Sweden)

Federico Lopez-Moya

2016-03-01

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

Persistence length of carboxymethyl cellulose as evaluated from size exclusion chromatography and potentiometric titrations.

NARCIS (Netherlands)

Hoogendam, C.W.; Keizer, de A.; Cohen Stuart, M.A.; Bijsterbosch, B.H.; Smit, J.A.M.; Dijk, van J.A.P.P.; Horst, van der P.M.; Batelaan, J.G.

1998-01-01

The intrinsic persistence length of carboxymethyl cellulose (CMC) is determined by size exclusion chromatography in combination with multiangle laser light scattering (SEC-MALLS) as well as from potentiometric titrations. Samples with degree of substitution (ds) ranging from 0.75 to 1.25 were

Microencapsulation of tramadol hydrochloride and physicochemical evaluation of formulations

International Nuclear Information System (INIS)

Murtaza, G.; Ahmad, M.

2009-01-01

The present project involves the microencapsulation of tramadol hydrochloride with ethocel using a non-solvent addition coacervation technique. The concentration of ethocel was varied to get a prolonged release profile. Then microparticles were compressed into tablets to study the variation of drug release between the microparticles and tablets. The microparticles were off white, aggregated and irregular in morphology having good percentage entrapment efficiency and percentage production yield. Dissolution study was made using USP XXIV apparatus I and II respectively, in 900 ml double distilled water at 50 rpm maintained at 37 degree C. An Initial burst effect was noted in the drug release behavior. Polyisobutylene concentration affected inversely the rate of drug release from microparticles. Dissolution media and stirring speed affected insignificantly (p>.05) the release pattern. Tramadol hydrochloride tablets showed good stability and reproducibility. UV and FTIR spectroscopy and X-Ray diffractometry proved that tramadol hydrochloride was completely and uniformly distributed in ethocel with out any strong interaction. The mechanism of drug release was anomalous diffusion that was best fit to Higuchi's equation. It can be concluded that multi-unit, slow-release tramadol hydrochloride microparticles can be formulated efficiently with non-solvent addition coacervation technique using ethocel. (author)

Probing cellular behaviors through nanopatterned chitosan membranes

International Nuclear Information System (INIS)

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

2013-01-01

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

Properties of Chitosan-Laminated Collagen Film

Directory of Open Access Journals (Sweden)

Vera Lazić

2012-01-01

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

Photocrosslinkable chitosan as a biological adhesive.

Science.gov (United States)

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

2000-02-01

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

Vitamin D-fortified chitosan films from mushroom waste

Science.gov (United States)

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

High Performace Liquid Chromtographic Determination of Nicardipine Hydrochloride in Human Plasma

Directory of Open Access Journals (Sweden)

Y. S. R. Krishnaiah

2004-01-01

Full Text Available A sensitive high-performance liquid chromatographic method was developed for the estimation of nicardipine hydrochloride in human plasma. Varying amount of nicardipine hydrochloride (2.5 to 150 ng/0.5 mL and fixed quantity (100 ng/0.5 mL of nifedipine (internal standard was added to blank human plasma, and a single step extraction was carried out with ethyl acetate. The mixture was centrifuged, ethyl acetate layer separated, dried and reconstituted with 100 μL of acetonitrile. Twenty microliters of this solution was injected into a reverse phase C-18 column using a mobile phase consisting of acetonitrile: 0.02 M potassium dihydrogen phosphate (pH 4.0 in the ratio of 60:40 v/v and the eluents were monitored at 239 nm. The method was validated for its linearity, precision and accuracy. The calibration curve was linear in the range of 5-150 ng/0.5 mL of plasma and the lower detection limit was 2.5 ng/0.5 mL of plasma. The intra- and inter-day variation was found to be less than 2.5% indicating that the method is highly precise. The mean recovery of nicardipine hydrochloride from plasma samples was 89.6±2.60%. The proposed HPLC method was applied for the estimation of nicardipine hydrochloride in human plasma after oral administration of an immediate release nicardipine hydrochloride capsule (dose 30 mg to 6 adult male volunteers. There was no interference of either the drug metabolites or other plasma components with the proposed HPLC method for the estimation of nicardipine hydrochloride in human plasma. Due to its simplicity, sensitivity, high precision and accuracy, the proposed HPLC method may be used for biopharmaceutical and pharmacokinetic evaluation of nicardipine hydrochloride and its formulations in humans

Controlling chitosan-based encapsulation for protein and vaccine delivery

Science.gov (United States)

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

2014-01-01

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

Surface modification of protein enhances encapsulation in chitosan nanoparticles

Science.gov (United States)

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

2018-04-01

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

Chitosan: collagen sponges. In vitro mineralization

International Nuclear Information System (INIS)

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

2011-01-01

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

SOLID-STATE FERMENTATIVE PRODUCTION AND BIOACTIVITY OF FUNGAL CHITOSAN

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Barry Aigbodion Omogbai

2013-10-01

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

Chitosan-based nanocarriers for antimalarials

Science.gov (United States)

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

2012-02-01

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

Electrophoretic deposition of composite hydroxyapatite-chitosan coatings

International Nuclear Information System (INIS)

Pang Xin; Zhitomirsky, Igor

2007-01-01

Cathodic electrophoretic deposition has been utilized for the fabrication of composite hydroxyapatite-chitosan coatings on 316L stainless steel substrates. The addition of chitosan to the hydroxyapatite suspensions promoted the electrophoretic deposition of the hydroxyapatite nanoparticles and resulted in the formation of composite coatings. The obtained coatings were investigated by X-ray diffraction, thermogravimetric and differential thermal analysis, scanning and transmission electron microscopy, potentiodynamic polarization measurements, and electrochemical impedance spectroscopy. It was shown that the deposit composition can be changed by a variation of the chitosan or hydroxyapatite concentration in the solutions. Experimental conditions were developed for the fabrication of hydroxyapatite-chitosan nanocomposites containing 40.9-89.8 wt.% hydroxyapatite. The method enabled the formation of adherent and uniform coatings of thicknesses up to 60 μm. X-ray studies revealed that the preferred orientation of the hydroxyapatite nanoparticles in the chitosan matrix increases with decreasing hydroxyapatite content in the composite coatings. The obtained coatings provided the corrosion protection for the 316L stainless steel substrates

Chitosan magnetic nanoparticles for drug delivery systems.

Science.gov (United States)

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

2017-06-01

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

Chitosan/bentonite bionanocomposites: morphology and mechanical behavior

International Nuclear Information System (INIS)

Braga, C.R.C.; Melo, F.M.A. de; Vitorino, I.F.; Fook, M.V.L.; Silva, S.M.L.

2010-01-01

This study chitosan/bentonite bionanocomposite films were prepared by solution intercalation process, seeking to investigate the effect of the chitosan/bentonite ratio (5/1 e 10/1) on the morphology and mechanical behavior of the bionanocomposites. It was used as nanophase, Argel sodium bentonite (AN), was provided by Bentonit Uniao Nordeste-BUN (Campina Grande, Brazil) and as biopolymer matrix the chitosan of low molecular weight and degree of deacetylation of 86,7% was supplied by Polymar (Fortaleza, Brazil). The bionanocomposites was investigated by X-ray diffraction and tensile properties. According to the results, the morphology and the mechanical behavior of the bionanocomposite was affected by the ratio of chitosan/bentonite. The chitosan/bentonite ratio (5/1 and 10/1) indicated the formation of an intercalated nanostructure and of the predominantly exfoliated nanostructure, respectively. And the considerable increases in the resistance to the traction were observed mainly for the bionanocomposite with predominantly exfoliated morphology. (author)

Systems of pyridine, piperidine, piperazine, morpholine hydrochlorides-terbium (dysprosium) chloride-water

International Nuclear Information System (INIS)

Gajfutdinova, R.K.; Sharafutdinova, A.A.; Murinov, Yu.I.

1988-01-01

The isothermal cross section method at 25 and 50 deg C is applied to study pyridine hydrochloride-terbium chloride-water (1) piperidine hydrochloride-dysprosium chloride-water (2), piperazine dihydrochloride-dysprosium chloride-water (3) and morpholine hydrochloride-terbium chloride (4) systems. Solubility isotherma prove the formation of incongruently soluble compound of the TbCl 3 x6C 5 H 5 NxHCl composition systems (1). The individuality of the new solid phase is proved by the chemical and DTA methods. Systems (2-4) are of a simple eutonic type

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

International Nuclear Information System (INIS)

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

2010-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2012-04-25

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

Production and physicochemical properties of carboxymethyl cellulose films enriched with spent coffee grounds polysaccharides

DEFF Research Database (Denmark)

Ballesteros, Lina F.; Cerqueira, Miguel A.; Teixeira, Jose A.

2018-01-01

Extracts rich in polysaccharides were obtained by alkali pretreatment (PA) or autohydrolysis (PB) of spent coffee grounds, and incorporated into a carboxymethyl cellulose (CMC)-based film aiming at the development of bio-based films with new functionalities. Different concentrations of PA or PB (up...

Aerogels from Chitosan Solutions in Ionic Liquids

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Gonzalo Santos-López

2017-12-01

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

Metal Complexation with Chitosan and its Grafted Copolymer

International Nuclear Information System (INIS)

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

2005-01-01

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

Characterization of blend hydrogels based on plasticized starch/cellulose acetate/carboxymethyl cellulose synthesized by electron beam irradiation

Energy Technology Data Exchange (ETDEWEB)

Senna, Magdy M., E-mail: magdysenna@hotmail.com [Radiation Chemistry Department, National Center for Radiation Research and Technology, Atomic Energy Authority, Cairo (Egypt); Mostafa, Abo El-Khair B. [Chemistry Department, College for Girls, Ain Shams University, Cairo (Egypt); Mahdy, Sanna R.; El-Naggar, Abdel Wahab M. [Radiation Chemistry Department, National Center for Radiation Research and Technology, Atomic Energy Authority, Cairo (Egypt)

2016-11-01

Highlights: • Semi-interpenetrating (IPN) blend hydrogels were synthesized by EB irradiation. • The hydrogels were based on starch/cellulose acetate/carboxymethyl cellulose blends. • The gelation, swelling, thermal and mechanical properties of hydrogels were studied. • The thermal stability was studied by determining kinetic energy by different methods. - Abstract: Blend hydrogels based on aqueous solutions of plasticized starch and different ratios of cellulose acetate (CA) and carboxymethyl cellulose (CMC) were prepared by electron beam irradiation (EB). The blends before and after EB irradiation were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The physico-chemical properties of blend hydrogels prepared by electron beam irradiation were improved compared to unirradiated blends.

Characterization of blend hydrogels based on plasticized starch/cellulose acetate/carboxymethyl cellulose synthesized by electron beam irradiation

International Nuclear Information System (INIS)

Senna, Magdy M.; Mostafa, Abo El-Khair B.; Mahdy, Sanna R.; El-Naggar, Abdel Wahab M.

2016-01-01

Highlights: • Semi-interpenetrating (IPN) blend hydrogels were synthesized by EB irradiation. • The hydrogels were based on starch/cellulose acetate/carboxymethyl cellulose blends. • The gelation, swelling, thermal and mechanical properties of hydrogels were studied. • The thermal stability was studied by determining kinetic energy by different methods. - Abstract: Blend hydrogels based on aqueous solutions of plasticized starch and different ratios of cellulose acetate (CA) and carboxymethyl cellulose (CMC) were prepared by electron beam irradiation (EB). The blends before and after EB irradiation were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The physico-chemical properties of blend hydrogels prepared by electron beam irradiation were improved compared to unirradiated blends.

Colestipol hydrochloride prophylaxis of diarrhea during pelvic radiotherapy

International Nuclear Information System (INIS)

Stryker, J.A.; Chung, C.K.; Layser, J.D.

1983-01-01

Thirty-three patients were randomized prior to pelvic radiotherapy to receive the bile acid-sequestering resin colestipol hydrochloride, 5 grams qid, during the entire time of their therapy or diphenoxylate hydrochloride and atropine sulfate 2.5-20 mg per day (control) if they experienced diarrhea. The colestipol patients also took diphenoxylate if they had diarrhea. The patients in the colestipol group often experienced nausea, vomiting, and abdominal cramps and 8 were forced to discontinue the drug. There was no difference in the weekly stool frequency between the colestipol and the control patients but the colestipol patients who took at least 50% of the prescribed dose required fewer diphenoxylate tablets than the controls. The data suggest that colestipol hydrochloride is not of value in preventing radiation-induced diarrhea because of the side effects associated with the drug, but the theory on which the use of bile acid-sequestering agents is based may be correct

Effect of chitosan coating on the characteristics of DPPC liposomes

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Mohsen M. Mady

2010-07-01

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

An enantioselective synthesis of S-γ-[(4-trifluoromethyl)phenoxy]benzenepropanamine-[3-14C] hydrochloride, an important metabolite of fluoxetine hydrochloride

International Nuclear Information System (INIS)

Wheeler, W.J.

1992-01-01

The S-enantiomer of γ-[(4-trifluoromethyl)phenoxy]benzenepropanamine-[3- 14 C] hydrochloride has been prepared in eight steps from acetophenone-[carbonyl- 14 C]. The key step in the synthesis involved the enantioselective reduction of R-2-chloroacetophenone-[1- 14 C]with (-)-diisopinocampheyl-chloroborane in an 86.5% yield. The chlorohydrin was converted to R-phenyloxirane-[1- 14 C], which was subsequently converted to the corresponding R-cyanohydrin by reaction with TMS-CN/CaO. Borane reduction and arylation, followed by salt formation yielded S-γ-[(4-trifluoromethyl)phenoxy]benzenepropanamine-[3- 14 C] hydrochloride. (author)

Hydrophobization and antimicrobial activity of chitosan and paper-based packaging material.

Science.gov (United States)

Bordenave, Nicolas; Grelier, Stephane; Coma, Veronique

2010-01-11

This study reports the elaboration of water-resistant, antimicrobial, chitosan and paper-based materials as environmentally friendly food packaging materials. Two types of papers were coated with chitosan-palmitic acid emulsions or with a blend of chitosan and O,O'-dipalmitoylchitosan (DPCT). Micromorphology studies showed that inclusion of hydrophobic compounds into the chitosan matrix was enhanced by grafting them onto chitosan and that this led to their penetration of the paper's core. Compared to chitosan-coated papers, the coating of chitosan-palmitic emulsion kept vapor-barrier properties unchanged (239 and 170 g.m(-2).d(-1) versus 241 and 161 g.m(-2).d(-1)), while the coating of chitosan-DPCT emulsion dramatically deteriorated them (441 and 442 g.m(-2).d(-1)). However, contact angle measurements (110-120 degrees after 1 min) and penetration dynamics analysis showed that both strategies improved liquid-water resistance of the materials. Kit-test showed that all hydrophobized chitosan-coated papers kept good grease barrier properties (degree of resistance 6-8/12). Finally, all chitosan-coated materials exhibited over 98% inhibition on Salmonella Typhimurium and Listeria monocytogenes .

Chitosan composite hydrogels reinforced with natural clay nanotubes.

Science.gov (United States)

Huang, Biao; Liu, Mingxian; Zhou, Changren

2017-11-01

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

Synthesis and characterization of carboxymethyl cellulose from office waste paper: A greener approach towards waste management

Energy Technology Data Exchange (ETDEWEB)

Joshi, Gyanesh, E-mail: joshig@icfre.org [Cellulose and Paper Division, Forest Research Institute, Dehradun 248006 (India); Naithani, Sanjay [Chemistry of Forest Products Division, Institute of Wood Science & Technology, Bangalore 560003 (India); Varshney, V.K. [Chemistry Division, Forest Research Institute, Dehradun 248006 (India); Bisht, Surendra S. [Chemistry of Forest Products Division, Institute of Wood Science & Technology, Bangalore 560003 (India); Rana, Vikas; Gupta, P.K. [Cellulose and Paper Division, Forest Research Institute, Dehradun 248006 (India)

2015-04-15

Highlights: • Carboxymethyl cellulose (CMC) was successfully prepared from waste paper. • CMC had maximum degree of substitution (DS) 1.07. • Rheological studies of CMC (DS, 1.07) showed non-Newtonian pseudoplastic behavior. • Characterization of CMC was done by FT-IR and NMR techniques. • Morphology of prepared CMC was studied by SEM. - Abstract: In the present study, functionalization of mixed office waste (MOW) paper has been carried out to synthesize carboxymethyl cellulose, a most widely used product for various applications. MOW was pulped and deinked prior to carboxymethylation. The deinked pulp yield was 80.62 ± 2.0% with 72.30 ± 1.50% deinkability factor. The deinked pulp was converted to CMC by alkalization followed by etherification using NaOH and ClCH{sub 2}COONa respectively, in an alcoholic medium. Maximum degree of substitution (DS) (1.07) of prepared CMC was achieved at 50 °C with 0.094 M and 0.108 M concentrations of NaOH and ClCH{sub 2}COONa respectively for 3 h reaction time. The rheological characteristics of 1–3% aqueous solution of optimized CMC product showed the non-Newtonian pseudoplastic behavior. Fourier transform infra red (FTIR), nuclear magnetic resonance (NMR) and scanning electron microscope (SEM) study were used to characterize the CMC product.

Physicochemical Characterization of Biopolymer Chitosan Extracted from Shrimp Shells

Directory of Open Access Journals (Sweden)

Nezamaddin Mengelizadeh

2015-02-01

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

Studies on electrospun nylon-6/chitosan complex nanofiber interactions

International Nuclear Information System (INIS)

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

2009-01-01

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

Synthesis, characterization, mucoadhesion and biocompatibility of thiolated carboxymethyl dextran-cysteine conjugate.

Science.gov (United States)

Shahnaz, G; Perera, G; Sakloetsakun, D; Rahmat, D; Bernkop-Schnürch, A

2010-05-21

This study was aimed at improving the mucoadhesive properties of carboxymethyl dextran by the covalent attachment of cysteine. Mediated by a carbodiimide, l-cysteine was covalently attached to the polymer. The resulting CMD-cysteine conjugate (CMD-(273) conjugate) displayed 273+/-20 micromol thiol groups per gram of polymer (mean+/-S.D.; n=3). Within 2h the viscosity of an aqueous mucus/CMD-(273) conjugate mixture pH 7.4 increased at 37 degrees C by more than 85% compared to a mucus/carboxymethyl dextran mixture indicating enlarged interactions between the mucus and the thiolated polymer. Due to the immobilization of cysteine, the swelling velocity of the polymer was significantly accelerated (ppolymer disintegrated within 15 min, whereas tablets of the CMD-(273) conjugate remained stable for 160 min (means+/-S.D.; n=3). Results from LDH and MTT assays on Caco-2 cells revealed 4.96+/-0.98% cytotoxicity and 94.1+/-0.9% cell viability for the CMD-(273) conjugate, respectively. Controlled release of model compound from CMD-(273) conjugate tablets was observed over 6h. These findings suggest that CMD-(273) conjugate is a promising novel polymer for drug delivery systems providing improved mucoadhesive and cohesive properties, greater stability and biocompatibility. Copyright 2010 Elsevier B.V. All rights reserved.

S-Adenosyl-S-carboxymethyl-l-homocysteine: a novel cofactor found in the putative tRNA-modifying enzyme CmoA

Energy Technology Data Exchange (ETDEWEB)

Byrne, Robert T.; Whelan, Fiona [University of York, Heslington YO10 5DD (United Kingdom); Aller, Pierre [Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom); Bird, Louise E. [OPPF-UK, Research Complex at Harwell, R92 Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0FA (United Kingdom); Oxford University, Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Dowle, Adam [University of York, Heslington YO10 5DD (United Kingdom); Lobley, Carina M. C. [Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom); Reddivari, Yamini; Nettleship, Joanne E.; Owens, Raymond J. [OPPF-UK, Research Complex at Harwell, R92 Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0FA (United Kingdom); Oxford University, Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Antson, Alfred A. [University of York, Heslington YO10 5DD (United Kingdom); Waterman, David G., E-mail: david.waterman@stfc.ac.uk [STFC, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0FA (United Kingdom); University of York, Heslington YO10 5DD (United Kingdom)

2013-06-01

The putative methyltransferase CmoA is involved in the nucleoside modification of transfer RNA. X-ray crystallography and mass spectrometry are used to show that it contains a novel SAM derivative, S-adenosyl-S-carboxymethyl-l-homocysteine, in which the donor methyl group is replaced by a carboxymethyl group. Uridine at position 34 of bacterial transfer RNAs is commonly modified to uridine-5-oxyacetic acid (cmo{sup 5}U) to increase the decoding capacity. The protein CmoA is involved in the formation of cmo{sup 5}U and was annotated as an S-adenosyl-l-methionine-dependent (SAM-dependent) methyltransferase on the basis of its sequence homology to other SAM-containing enzymes. However, both the crystal structure of Escherichia coli CmoA at 1.73 Å resolution and mass spectrometry demonstrate that it contains a novel cofactor, S-adenosyl-S-carboxymethyl-l-homocysteine (SCM-SAH), in which the donor methyl group is substituted by a carboxymethyl group. The carboxyl moiety forms a salt-bridge interaction with Arg199 that is conserved in a large group of CmoA-related proteins but is not conserved in other SAM-containing enzymes. This raises the possibility that a number of enzymes that have previously been annotated as SAM-dependent are in fact SCM-SAH-dependent. Indeed, inspection of electron density for one such enzyme with known X-ray structure, PDB entry http://scripts.iucr.org/cgi-bin/cr.cgi?rm, suggests that the active site contains SCM-SAH and not SAM.

Recent advances in chitosan-based nanoparticulate pulmonary drug delivery

Science.gov (United States)

Islam, Nazrul; Ferro, Vito

2016-07-01

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

Sorption of technetium on composite chitosan-hydroxyapatite from aqueous solutions

International Nuclear Information System (INIS)

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

2013-01-01

Biomaterials such as natural polymers (chitosan) and hydroxyapatite have an important application in material for bone replacement. Most of chitosan/hydroxyapatite composites are prepared by mixing hydroxyapatite particles with chitosan matrices. Another method of preparation of chitosan/hydroxyapatite composite is in-situ generation of nano-hydroxyapatite in chitosan matrix. The most common biomaterial used in the past years in hard tissue regeneration was hydroxyapatite, owing to its properties as biocompatibility, bioactivity, non-toxicity, non-immunogenicity etc. Chitosan is a polyaminosacharide, partially deacetylated product of chitin. Chitosan can be used in combination with other materials to enhance bone growth such as bone filling paste. The aims of this work were: the influence of the contact time on sorption of pertechnate anions on chitosan/hydroxyapatite composites; the effect of pH on sorption of pertechnate anions on chitosan/hydroxyapatite composites; the effect of foreign ions on sorption of pertechnate anions on chitosan/hydroxyapatite composites. The author concluded: the percentage of technetium sorption after 1 hour of contact time was > 97 %. In the initial pH range of 2.9-10.2, the percentage of technetium sorption on chitosan/hydroxyapatite composites CH/HA(A), CH/HA(B), CH/HA 30:70, ZCH was > 98 % and on CH/HA 50:50 was > 94%. The competition effect of Fe 2+ towards TcO 4 :- sorption is stronger than competition effect of other observed cations for all examined composites with the same weight ratio. The percentage of the technetium sorption was the same for all composites with the weight ratio of 30:70. (authors)

Novel procedure to enhance PLA surface properties by chitosan irreversible immobilization

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Stoleru, Elena; Dumitriu, Raluca Petronela [Petru Poni Institute of Macromolecular Chemistry, Grigore Ghica Voda Alley, 41A, 700487 Iasi (Romania); Munteanu, Bogdanel Silvestru [“Al. I. Cuza” University, Faculty of Physics, 11 Carol I Blvd., 700506 Iasi (Romania); Zaharescu, Traian [INCDIE ICPE CA, Bucharest (Romania); Tănase, Elisabeta Elena; Mitelut, Amalia [Industrial Biotechnology Department, Faculty of Biotechnology – USAMV Bucharest (Romania); Ailiesei, Gabriela-Liliana [Petru Poni Institute of Macromolecular Chemistry, Grigore Ghica Voda Alley, 41A, 700487 Iasi (Romania); Vasile, Cornelia, E-mail: cvasile@icmpp.ro [Petru Poni Institute of Macromolecular Chemistry, Grigore Ghica Voda Alley, 41A, 700487 Iasi (Romania)

2016-03-30

Graphical abstract: - Highlights: • PLA requires functionalization prior to surface attaching chitosan. • Chitosan with different molecular weights was grafted onto PLA surface. • Antibacterial, antifungal, antioxidant PLA-based materials are obtained. • Nano-fibers coatings obtained by electrospinning of high molecular weight chitosan. - Abstract: A novel two step procedure was applied for poly(lactic acid) (PLA) functionalization consisting in the exposure to cold radiofrequency plasma in nitrogen atmosphere or to gamma irradiation followed by “grafting to” of a chitosan layer using carbodiimide chemistry. The adhesion and stability of the deposited surface layer was assured by plasma/gamma irradiation treatment while the chitosan layer offers antifungal/antibacterial/antioxidant activities. Chitosan with different viscosities/deacetylation degree was deposited by electrospinning or immersion methods. Correlations between rheological behavior of chitosan solutions and chitosan layer deposition conditions are made. The PLA surface properties were investigated by water contact angle measurements, ATR-FTIR spectroscopy, AFM, chemiluminiscence, etc. It has been established that the surface roughness increases direct proportional with cold plasma duration and gamma irradiation dose and further increases by chitosan coating which at its turn depends on chitosan characteristics (viscosity and deacetylation degree) and method of deposition. Nano-fibers with relatively homogeneous and reproducible features are obtained by electrospinning of highly viscous chitosan while with the other two types of chitosan both microparticles and nano-fibers are formed. The chitosan coating obtained by immersion is more homogenous and compact and has a better antibacterial activity than the electrospun layer as fiber meshes.

In-silico analysis of amotosalen hydrochloride binding to CD-61 of platelets

International Nuclear Information System (INIS)

Chaudhary, H.T.

2016-01-01

To determine the docking of Amotosalen hydrochloride (AH) at CD-61 of platelets, and to suggest the cause of bleeding in AH treated platelets transfusion. Study Design: Descriptive study. Place and Duration of Study: Medical College, Taif University, Taif, Saudi Arabia, from October 2014 to May 2015. Methodology: The study was carried out in-silico. PDB (protein data bank) code of Tirofiban bound to CD-61 was 2vdm. CD-61 was docked with Tirofiban using online docking tools, i.e. Patchdock and Firedock. Then, Amotosalen hydrochloride and CD-61 were also docked. Best docking poses to active sites of 2vdm were found. Ligplot of interactions of ligands and CD-61 were obtained. Then comparison of hydrogen bonds, hydrogen bond lengths, and hydrophobic bonds of 2vdm molecule and best poses of docking results were done. Patchdock and Firedock results of best poses were also analysed using SPSS version 16. Results: More amino acids were involved in hydrogen and hydrophobic bonds in Patchdock and Firedock docking of Amotosalen hydrochloride with CD-61 than Patchdock and Firedock docking of CD-61 with Tirofiban. The binding energy was more in latter than former. Conclusion: Amotosalen hydrochloride binds to the active site of CD-61 with weaker binding force. Haemorrhage seen in Amotosalen hydrochloride-treated platelets might be due to binding of Amotosalen hydrochloride to CD-61. (author)

HPLC method validation for modernization of the tetracycline hydrochloride capsule USP monograph

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Emad M. Hussien

2014-12-01

Full Text Available This paper is a continuation to our previous work aiming at development and validation of a reversed-phase HPLC for modernization of tetracycline-related USP monographs and the USP general chapter . Previous results showed that the method is accurate and precise for the assay of tetracycline hydrochloride and the limit of 4-epianhydrotetracycline impurity in the drug substance and oral suspension monographs. The aim of the current paper is to examine the feasibility of the method for modernization of USP tetracycline hydrochloride capsule monograph. Specificity, linearity, accuracy and precision were examined for tetracycline hydrochloride assay and 4-epianhydrotetracycline limit. The method was linear in the concentration range from 80% to 160% (r>0.9998 of the assay concentration (0.1 mg/mL for tetracycline hydrochloride and from 50% to 150% (r>0.997 of the acceptance criteria specified in tetracycline hydrochloride capsule monograph for 4-epianhydrotetracycline (NMT 3.0%. The recovery at three concentration levels for tetracycline hydrochloride assay was between 99% and 101% and the RSD from six preparations at the concentration 0.1 mg/mL is less than 0.6%. The recovery for 4-epianhydrotetracycline limit procedure over the concentration range from 50% to 150% is between 96% and 102% with RSD less than 5%. The results met the specified acceptance criteria.

Viscometric studies of chitosan radiation degradation

International Nuclear Information System (INIS)

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

2001-01-01

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

Characterization of different substituted carboxymethyl starch microgels and their interactions with lysozyme.

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Bao Zhang

Full Text Available A carboxymethyl starch (CMS microgel system was prepared for the control of uptaking and releasing proteins (lysozyme. The physicochemical properties of microgels in various degrees of substitution (DS were determined by thermal gravimetric analysis (TGA, swelling degree, and rheological analysis. The microgel particle size mostly ranged from 25 µm to 45 µm. The result obtained from the TGA studies indicated that carboxymethylation decreased the thermal stability of starch, but crosslinking increased the thermal stability of CMS. The CMS microgels showed typical pH sensitivity, and the swelling degree of microgel increased with the increasing of DS and pH, because of the large amounts of carboxyl group ionization. The samples (2.25% could behave as viscoelastic solids since the storage modulus was larger than the loss modulus over the entire frequency range. The protein uptake increased with increasing pH and DS at low salt concentration. The optimal pH shifted to lower pH with increasing ionic strength. The saturated protein uptake decreased with increasing ionic strength at each pH. The protein was easily released from the microgel with high pH and high salt concentration.

Chitosan-Based Polymer Blends: Current Status and applications

International Nuclear Information System (INIS)

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

2014-01-01

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

Effect of Gamma irradiation on the antimicrobial activity of selenomorphiline hydrochloride

International Nuclear Information System (INIS)

Bashand, A.S.

2002-01-01

The effect of selenomorphiline hydrochloride on dell growth of two steains of bacteria bacillus subtilis as a gram positive and esherichia coli as a gram negative strain and asperagillus flavus as a fungal strain were investigated in batch broth culture supplemented with different concentrations (50, 100, 150, 200, 300 and 400 mg/ml) of irradiated se (1,2,4 KGY) and its control (non irradiated). The data showed that the antibacterial activity of selenomorphiline hydrochloride is concentration and time depenent. The doses 2 doses 2 and 3 KGY of Gamma-radiation were actually the most effective doses activating selenomorphiline hydrochloride as antibiotic

Humidity Responsive Photonic Sensor based on a Carboxymethyl Cellulose Mechanical Actuator

OpenAIRE

Hartings, Matthew; Douglass, Kevin O.; Neice, Claire; Ahmed, Zeeshan

2017-01-01

We describe an intuitive and simple method for exploiting humidity-driven volume changes in carboxymethyl cellulose (CMC) to fabricate a humidity responsive actuator on a glass fiber substrate. We optimize this platform to generate a photonic-based humidity sensor where CMC coated on a fiber optic containing a fiber Bragg grating (FBG) actuates a mechanical strain in response to humidity changes. The humidity-driven mechanical deformation of the FBG results in a large lin...

Investigation of Galactosylated Low Molecular Weight Chitosan ...

African Journals Online (AJOL)

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

Biowaiver Monographs for Immediate Release Solid Oral Dosage Forms: Proguanil Hydrochloride.

Science.gov (United States)

Plöger, Gerlinde F; Abrahamsson, Bertil; Cristofoletti, Rodrigo; Groot, Dirk W; Langguth, Peter; Mehta, Mehul U; Parr, Alan; Polli, James E; Shah, Vinod P; Tajiri, Tomokazu; Dressman, Jennifer B

2018-07-01

Literature data relevant to the decision to waive in vivo bioequivalence testing for the approval of generic immediate release solid oral dosage forms of proguanil hydrochloride are reviewed. To elucidate the Biopharmaceutics Classification System (BCS) classification, experimental solubility and dissolution studies were also carried out. The antimalarial proguanil hydrochloride, effective via the parent compound proguanil and the metabolite cycloguanil, is not considered to be a narrow therapeutic index drug. Proguanil hydrochloride salt was shown to be highly soluble according to the U.S. Food and Drug Administration, World Health Organization, and European Medicines Agency guidelines, but data for permeability are inconclusive. Therefore, proguanil hydrochloride is conservatively classified as a BCS class 3 substance. In view of this information and the assessment of risks associated with a false positive decision, a BCS-based biowaiver approval procedure can be recommended for orally administered solid immediate release products containing proguanil hydrochloride, provided well-known excipients are used in usual amounts and provided the in vitro dissolution of the test and reference products is very rapid (85% or more are dissolved in 15 min at pH 1.2, 4.5, and 6.8) and is performed according to the current requirements for BCS-based biowaivers. Copyright © 2018 American Pharmacists Association®. All rights reserved.

3D Bioprinting of Carboxymethylated-Periodate Oxidized Nanocellulose Constructs for Wound Dressing Applications

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Adam Rees

2015-01-01

Full Text Available Nanocellulose has a variety of advantages, which make the material most suitable for use in biomedical devices such as wound dressings. The material is strong, allows for production of transparent films, provides a moist wound healing environment, and can form elastic gels with bioresponsive characteristics. In this study, we explore the application of nanocellulose as a bioink for modifying film surfaces by a bioprinting process. Two different nanocelluloses were used, prepared with TEMPO mediated oxidation and a combination of carboxymethylation and periodate oxidation. The combination of carboxymethylation and periodate oxidation produced a homogeneous material with short nanofibrils, having widths <20 nm and lengths <200 nm. The small dimensions of the nanofibrils reduced the viscosity of the nanocellulose, thus yielding a material with good rheological properties for use as a bioink. The nanocellulose bioink was thus used for printing 3D porous structures, which is exemplified in this study. We also demonstrated that both nanocelluloses did not support bacterial growth, which is an interesting property of these novel materials.

Analgesic Effect of Intraperitoneal Bupivacaine Hydrochloride After Laparoscopic Sleeve Gastrectomy: a Randomized Clinical Trial.

Science.gov (United States)

Alamdari, Nasser Malekpour; Bakhtiyari, Mahmood; Gholizadeh, Barmak; Shariati, Catrine

2018-03-01

The indications for sleeve gastrectomy as a primary procedure for the surgical treatment of morbid obesity have increased worldwide. Pain is the most common complaint for patients on the first day after laparoscopic sleeve gastrectomy. There are various methods for decreasing pain after laparoscopic sleeve gastrectomy such as the use of intraperitoneal bupivacaine hydrochloride. This clinical trial was an attempt to discover the effects of intraperitoneal bupivacaine hydrochloride on alleviating postoperative pain after laparoscopic sleeve gastrectomy. In general, 120 patients meeting the inclusion criteria were enrolled. Patients were randomly allocated into two interventions and control groups using a balanced block randomization technique. One group received intraperitoneal bupivacaine hydrochloride (30 cm 3 ), and the other group served as the control one and did not receive bupivacaine hydrochloride. Diclofenac suppository and paracetamol injection were administered to both groups for postoperative pain management. The mean subjective postoperative pain score was significantly decreased in patients who received intraperitoneal bupivacaine hydrochloride within the first 24 h after the surgery; thus, the instillation of bupivacaine hydrochloride was beneficial in managing postoperative pain. The intraoperative peritoneal irrigation of bupivacaine hydrochloride (30 cm 3 , 0.25%) in sleeve gastrectomy patients was safe and effective in reducing postoperative pain, nausea, and vomiting (IRCT2016120329181N4).

In vivo evaluation of thiolated chitosan tablets for oral insulin delivery.

Science.gov (United States)

Millotti, Gioconda; Laffleur, Flavia; Perera, Glen; Vigl, Claudia; Pickl, Karin; Sinner, Frank; Bernkop-Schnürch, Andreas

2014-10-01

Chitosan-6-mercaptonicotinic acid (chitosan-6-MNA) is a thiolated chitosan with strong mucoadhesive properties and a pH-independent reactivity. This study aimed to evaluate the in vivo potential for the oral delivery of insulin. The comparison of the nonconjugated chitosan and chitosan-6-MNA was performed on several studies such as mucoadhesion, release, and in vivo studies. Thiolated chitosan formulations were both about 80-fold more mucoadhesive compared with unmodified ones. The thiolated chitosan tablets showed a sustained release for 5 h for the polymer of 20 kDa and 8 h for the polymer of 400 kDa. Human insulin was quantified in rats' plasma by means of ELISA specific for human insulin with no cross-reactivity with the endogenous insulin. In vivo results showed thiolation having a tremendous impact on the absorption of insulin. The absolute bioavailabilities were 0.73% for chitosan-6-MNA of 20 kDa and 0.62% for chitosan-6-MNA 400 kDa. The areas under the concentration-time curves (AUC) of chitosan-6-MNA formulations compared with unmodified chitosan were 4.8-fold improved for the polymer of 20 kDa and 21.02-fold improved for the polymer of 400 kDa. The improvement in the AUC with regard to the most promising aliphatic thiomer was up to 6.8-fold. Therefore, chitosan-6-MNA represents a promising excipient for the oral delivery of insulin. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

The molecular understanding of interfacial interactions of functionalized graphene and chitosan

International Nuclear Information System (INIS)

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

2016-01-01

Graphical abstract: The type of the functional groups can be used to modulating interactions between graphene sheet and chitosan. - Highlights: • Investigate interfacial interactions between chitosan and functionalized graphene by DFT. • Observe covalent linkages between COOH-modified graphene and chitosan units. • Multi-functionalized graphene regulates the interfacial interactions with chitosan. • It is useful for guiding the preparation of graphene/chitosan composites. - Abstract: Graphene-reinforced chitosan scaffolds have been extensively studied for several years as promising hard tissue replacements. However, the interfacial interactions between graphene and chitosan are strongly related to the solubility, processability, and mechanical properties of graphene-reinforced chitosan (G–C) composites. The functionalization of graphene is regarded as the most effective way to improve the abovementioned properties of the G–C composite. In this study, the interfacial interactions between chitosan and functionalized graphene sheets with carboxylization (COOH-), amination (NH 2 -), and hydroxylation (OH-) groups were systematically studied at the electronic level using the method of ab initio simulations based on quantum mechanics theory and the observations were compared with reported experimental results. The covalent linkages between COOH-modified graphene and the chitosan units were demonstrated and the combination of multi-functionalization on graphene could regulate the interfacial interactions between graphene and the chitosan. The interfacial interactions between chitosan and properly functionalized graphene are critical for the preparation of G–C-based composites for tissue engineering scaffolds and other applications.

Highly Response and Sensitivity Chitosan-Polyvinyl alcohol Based Hexanal Sensors

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Abd Wahab Nur Zuraihan

2016-01-01

Full Text Available This work is to study the sensing properties of chitosanpolyvinyl alcohol film sensors upon hexanal gas exposure using vapour sensing technique. The sensor fabrication process was done using electrochemical deposition method by deposit the sensing materials on the gold patterned electrode with chitosan/PVA. The response value of chitosan-PVA film sensors towards hexanal was taken as an output voltage using electrical testing method. In this study, 1.75% of chitosan with 5% of PVA were mixed with the ratio of (95:5 was tested upon exposure to hexanal gas. The concentration of the hexanal was varied as 10 ppm, 20 ppm, 30 ppm. It was found that the chitosan-PVA film sensors showed fast response, stable, good stability, good recovery, repeatable and good sensitivity towards hexanal exposure. The morphology of the pure chitosan and chitosan-PVA was analyzed by scanning electron microscope (SEM and the interaction between chitosan and PVA was examined by Fourier Transform Infrared Spectroscopy (FTIR. The FTIR results indicate the changes in characteristics of the spectral peaks due to the formation of the intermolecular bonds between chitosan and PVA. The SEM morphology of the composites showed flat smooth surface that be a sign of uniform distribution of chitosan and PVA mixture throughout the films.

Fabrication and application of coaxial polyvinyl alcohol/chitosan nanofiber membranes

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Kuo Ting-Yun

2017-12-01

Full Text Available It is difficult to fabricate chitosan-wrapped coaxial nanofibers, because highly viscous chitosan solutions might hinder the manufacturing process. To overcome this difficulty, our newly developed method, which included the addition of a small amount of gum arabic, was utilized to prepare much less viscous chitosan solutions. In this way, coaxial polyvinyl alcohol (PVA/chitosan (as core/shell nanofiber membranes were fabricated successfully by coaxial electrospinning. The core/shell structures were confirmed by TEM, and the existence of PVA and chitosan was also verified using FT-IR and TGA. The tensile strength of the nanofiber membranes was increased from 0.6-0.7 MPa to 0.8-0.9 MPa after being crosslinked with glutaraldehyde. The application potential of the PVA/chitosan nanofiber membranes was tested in drug release experiments by loading the core (PVA with theophylline as a model drug. The use of the coaxial PVA/chitosan nanofiber membranes in drug release extended the release time of theophylline from 5 minutes to 24 hours. Further, the release mechanisms could be described by the Korsmeyer-Peppas model. In summary, by combining the advantages of PVA and chitosan (good mechanical strength and good biocompatibility respectively, the coaxial PVA/chitosan nanofiber membranes are potential biomaterials for various biomedical applications.

Study on growth-promotion of paddy plants treated with oligo chitosan

International Nuclear Information System (INIS)

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

2010-01-01

Chitosan has been degraded to produced oligo chitosan with different molecular weight using gamma ray irradiation from a Co-60 source in solid state (powder form) and liquid state (aqueous solution). Study on growth promotion of paddy plants was done using oligo chitosan and conventional plant growth promoter as a comparison. Oligo chitosan was used with different molecular weight and different concentrations. Smaller molecular weight of oligo chitosan with smaller concentration showed better result than bigger molecular weight of oligo chitosan as a plant growth promoter. This study also showed that conventional growth promoter can be replaced with oligo chitosan as it is more effective as plant growth promoter as well as more environmental friendly. (author)

Chitosan: An Update on Potential Biomedical and Pharmaceutical Applications

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Randy Chi Fai Cheung

2015-08-01

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

Chitosan: An Update on Potential Biomedical and Pharmaceutical Applications

Science.gov (United States)

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

2015-01-01

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

21 CFR 522.1662 - Oxytetracycline hydrochloride implantation or injectable dosage forms.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride implantation or injectable dosage forms. 522.1662 Section 522.1662 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.1662 Oxytetracycline hydrochloride implantation or injectable...

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

Science.gov (United States)

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

2017-12-01

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

The production of fully deacetylated chitosan by compression method

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Xiaofei He

2016-03-01

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

Nuclear imaging evaluation of galactosylation of chitosan

International Nuclear Information System (INIS)

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

2004-01-01

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

Chitosan microspheres in novel drug delivery systems.

Science.gov (United States)

Mitra, Analava; Dey, Baishakhi

2011-07-01

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

Immobilization of swift foxes with ketamine hydrochloride-xylazine hydrochloride

Science.gov (United States)

Telesco, R.L.; Sovada, Marsha A.

2002-01-01

There is an increasing need to develop field immobilization techniques that allow researchers to handle safely swift foxes (Vulpes velox) with minimal risk of stress or injury. We immobilized captive swift foxes to determine the safety and effectiveness of ketamine hydrochloride and xylazine hydrochloride at different dosages. We attempted to determine appropriate dosages to immobilize swift foxes for an adequate field-handling period based on three anesthesia intervals (induction period, immobilization period, and recovery period) and physiologic responses (rectal temperature, respiration rate, and heart rate). Between October 1998–July 1999, we conducted four trials, evaluating three different dosage ratios of ketamine and xylazine (2.27:1.2, 5.68:1.2, and 11.4:1.2 mg/kg ketamine:mg/kg xylazine, respectively), followed by a fourth trial with a higher dosage at the median ratio (11.4 mg/kg ketamine:2.4 mg/kg xylazine). We found little difference in induction and recovery periods among trials 1–3, but immobilization time increased with increasing dosage (Pimmobilization period and recovery period increased in trial 4 compared with trials 1–3 (P≤0.03). There was a high variation in responses of individual foxes across trials, making it difficult to identify an appropriate dosage for field handling. Heart rate and respiration rates were depressed but all physiologic measures remained within normal parameters established for domestic canids. We recommend a dosage ratio of 10 mg/kg ketamine to 1 mg/kg xylazine to immobilize swift foxes for field handling.

Evaluation of dose dependent antimicrobial activity of self-assembled chitosan, nano silver and chitosan-nano silver composite against several pathogens.

Science.gov (United States)

Tareq, Foysal Kabir; Fayzunnesa, Mst; Kabir, Md Shahariar; Nuzat, Musrat

2018-01-01

The aim of this investigation to preparation of silver nanoparticles organized chitosan nano polymer, which effective against microbial and pathogens, when apply to liquid medium and edible food products surface, will rescue the growth of microbes. Self-assembly approach used to synthesis of silver nanoparticles and silver nanoparticles organized chitosan nano polymer. Silver nanoparticles and silver nanoparticles organized chitosan nano polymer and film characterized using Ultra-violate visible spectrometer (UV-vis), X-ray diffraction (X-ray), and Scanning electronic microscope (SEM). The crystalline structured protein capped nano silver successfully synthesized at range of 12 nm-29 nm and organized into chitosan nano polymer. Antimicrobial ingredient in liquid medium and food product surface provide to rescue oxidative change and growth of microorganism to provide higher safety. The silver nanoparticles organized chitosan nano polymer caused the death of microorganism. The materials in nano scale synthesized successfully using self-assembly method, which showed good antimicrobial properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthesis of PVA-Chitosan Hydrogels for Wound Dressing Using Gamma Irradiation. Part II: Antibacterial Activity of PVA/Chitosan Hydrogel Synthesized by Gamma Irradiation

International Nuclear Information System (INIS)

Mahlous, M.; Tahtat, D.; Benamer, S.; Nacer Khodja, A.; Larbi Youcef, S.

2010-01-01

Poly(vinyl alcohol) (PVA) is a synthetic polymer used in a large range of medical, commercial, industrial and food applications, manufacture of paper products, surgical threads, wound care, and food-contact applications. It was recently used as a coating for dietary supplements and pharmaceutical capsules. Cross-linked PVA microspheres are also used for controlled release of oral drugs. Chitin, a polysaccharide from which chitosan is derived, is the second most abundant natural polysaccharide after cellulose. Chitin is obtained from the exoskeletons (crab, shrimps and squid pen) fungi, insects, and some algae. Chitosan, a non toxic and biocompatible cationic polysaccharide, is produced by partial deacetylation of chitin; these properties of chitosan provide high potential for many applications. Chitosan has been widely used in vastly diverse fields, such as in biomedical applications drug delivery in agriculture metal ion sorption. The most important characteristic of chitosan is the deacetylation degree (DD) which influences its physical and chemical behaviors. Evaluation of DD can be carried out by FT-IR spectroscopy potentiometric titration, first derivative UV spectrophotometry, 1 H-NMR and X-ray diffraction. Chitosan extracted from squid pen chitin is inherently purer than crustacean chitosans, it does not contain large amounts of calcium carbonate, and it does contain large amounts of protein. The purity of squid pen chitosan makes it particularly suitable for medical and cosmetic application. Application of radiation for the formation of hydrogels for medical use offers a unique possibility to combine the formation and sterilization of the product in a single technological step. The main aim of this study is to synthesis poly(vinyl alcohol) hydrogels containing different moieties of chitosan by gamma irradiation at a dose of 25 kGy, and investigate the antibacterial effect of chitosan contained in the hydrogel

Development of hydroxyapatite-chitosan gel sunscreen combating clinical multidrug-resistant bacteria

Science.gov (United States)

Morsy, Reda; Ali, Sameh S.; El-Shetehy, Mohamed

2017-09-01

The several harmful effects on infected human skin resulting from exposure to the sun's UV radiation generate an interest in the development of a multifunctional hydroxyapatite-chitosan (HAp-chitosan) gel that works as an antibacterial sunscreen agent for skin care. In this work, HAp-chitosan gel was synthesized via coprecipitation method by dissolving chitosan in phosphoric acid and adding HAp. The characteristics of HAp-chitosan composite were investigated by conventional techniques, such as XRD, FTIR, and SEM techniques, while its sunscreen property was investigated by UV-spectroscopy. In addition to the influence of the gel on bacterial cell morphology, the antibacterial activity of HAp-chitosan gel against clinical multidrug resistant skin pathogens, such as Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa has been studied. The results revealed the formation of HAp-chitosan gel having nanosized particles, which confers protection against UV-radiation. The antibacterial activity records showed that chitosan-HAp gel exhibits a significant effect on the growth and ultrastructure of multi-drug resistant bacterial activities. Therefore, the chitosan-HAp gel is promising for skin health care as an antibacterial sunscreen.

UV Spectrophotometric Method for theEstimation of Itopride Hydrochloride in Pharmaceutical Formulation

OpenAIRE

K. R. Gupta; R. R. Joshi; R. B. Chawla; S. G. Wadodkar

2010-01-01

Three simple, precise and economical UV methods have been developed for the estimation of itopride hydrochloride in pharmaceutical formulations. Itopride hydrochloride in distilled water shows the maximum absorbance at 258.0 nm (Method A) and in first order derivative spectra of the same shows sharp peak at 247.0 nm, when n = 1 (Method B). Method C utilises area under curve (AUC) in the wavelength range from 262.0-254.0 nm for analysis of itopride hydrochloride. The drug was found to obey Bee...

Toxicity tests, antioxidant activity, and antimicrobial activity of chitosan

Science.gov (United States)

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

2018-04-01

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

FTIR studies of chitosan acetate based polymer electrolytes

International Nuclear Information System (INIS)

Osman, Z.; Arof, A.K.

2003-01-01

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

Anti-Inflammatory Effects of Berberine Hydrochloride in an LPS-Induced Murine Model of Mastitis

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Xichun Wang

2018-01-01

Full Text Available Berberine hydrochloride is an isoquinoline type alkaloid extracted from Berberidaceae, Rutaceae, and other plants. Previous reports have shown that berberine hydrochloride has anti-inflammatory properties. However, the underlying molecular mechanisms remain unclear. In this study, a lipopolysaccharide- (LPS- induced murine model of mastitis was established to explore the anti-inflammatory action of berberine hydrochloride. Sixty mice that had been lactating for 5–7 days were randomly divided into six groups, including control, LPS, three berberine hydrochloride treatment groups (5, 10, and 20 mg/kg, and a dexamethasone (DEX (5 mg/kg group. Berberine hydrochloride was administered intraperitoneally 1 h before and 12 h after LPS-induced mastitis, and all mice were sacrificed 24 h after LPS induction. The pathological and histopathological changes of the mammary glands were observed. The concentrations and mRNA expressions of TNF-α, IL-1β, and IL-6 were measured by ELISA and qRT-PCR. The activation of TLR4 and NF-κB signaling pathways was analyzed by Western blot. Results indicated that berberine hydrochloride significantly attenuated neutrophil infiltration and dose-dependently decreased the secretion and mRNA expressions of TNF-α, IL-1β, and IL-6 within a certain range. Furthermore, berberine hydrochloride suppressed LPS-induced TLR4 and NF-κB p65 activation and the phosphorylation of I-κB. Berberine hydrochloride can provide mice robust protection from LPS-induced mastitis, potentially via the TLR4 and NF-κB pathway.

Anti-Inflammatory Effects of Berberine Hydrochloride in an LPS-Induced Murine Model of Mastitis

Science.gov (United States)

Feng, Shibin; Ding, Nana; He, Yanting; Li, Cheng; Li, Manman; Ding, Xuedong; Ding, Hongyan; Li, Jinchun

2018-01-01

Berberine hydrochloride is an isoquinoline type alkaloid extracted from Berberidaceae, Rutaceae, and other plants. Previous reports have shown that berberine hydrochloride has anti-inflammatory properties. However, the underlying molecular mechanisms remain unclear. In this study, a lipopolysaccharide- (LPS-) induced murine model of mastitis was established to explore the anti-inflammatory action of berberine hydrochloride. Sixty mice that had been lactating for 5–7 days were randomly divided into six groups, including control, LPS, three berberine hydrochloride treatment groups (5, 10, and 20 mg/kg), and a dexamethasone (DEX) (5 mg/kg) group. Berberine hydrochloride was administered intraperitoneally 1 h before and 12 h after LPS-induced mastitis, and all mice were sacrificed 24 h after LPS induction. The pathological and histopathological changes of the mammary glands were observed. The concentrations and mRNA expressions of TNF-α, IL-1β, and IL-6 were measured by ELISA and qRT-PCR. The activation of TLR4 and NF-κB signaling pathways was analyzed by Western blot. Results indicated that berberine hydrochloride significantly attenuated neutrophil infiltration and dose-dependently decreased the secretion and mRNA expressions of TNF-α, IL-1β, and IL-6 within a certain range. Furthermore, berberine hydrochloride suppressed LPS-induced TLR4 and NF-κB p65 activation and the phosphorylation of I-κB. Berberine hydrochloride can provide mice robust protection from LPS-induced mastitis, potentially via the TLR4 and NF-κB pathway.

Solid polymer electrolyte from phosphorylated chitosan

Energy Technology Data Exchange (ETDEWEB)

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

2014-03-24

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

PLA/chitosan/keratin composites for biomedical applications

Energy Technology Data Exchange (ETDEWEB)

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

2014-07-01

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

PLA/chitosan/keratin composites for biomedical applications

International Nuclear Information System (INIS)

Tanase, Constantin Edi; Spiridon, Iuliana

2014-01-01

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

21 CFR 524.1662 - Oxytetracycline hydrochloride ophthalmic and topical dosage forms.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride ophthalmic and topical dosage forms. 524.1662 Section 524.1662 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... DOSAGE FORM NEW ANIMAL DRUGS § 524.1662 Oxytetracycline hydrochloride ophthalmic and topical dosage forms. ...

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

African Journals Online (AJOL)

Erah

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

Design, characterization and ex vivo evaluation of chitosan film integrating of insulin nanoparticles composed of thiolated chitosan derivative for buccal delivery of insulin.

Science.gov (United States)

Mortazavian, Elaheh; Dorkoosh, Farid Abedin; Rafiee-Tehrani, Morteza

2014-05-01

The purpose of this study is to optimize and characterize of chitosan buccal film for delivery of insulin nanoparticles that were prepared from thiolated dimethyl ethyl chitosan (DMEC-Cys). Insulin nanoparticles composed of chitosan and dimethyl ethyl chitosan (DMEC) were also prepared as control groups. The release of insulin from nanoparticles was studied in vitro in phosphate buffer solution (PBS) pH 7.4. Optimization of chitosan buccal films has been carried out by central composite design (CCD) response surface methodology. Independent variables were different amounts of chitosan and glycerol as mucoadhesive polymer and plasticizer, respectively. Tensile strength and bioadhesion force were considered as dependent variables. Ex vivo study was performed on excised rabbit buccal mucosa. Optimized insulin nanoparticles were obtained with acceptable physicochemical properties. In vitro release profile of insulin nanoparticles revealed that the highest solubility of nanoparticles in aqueous media is related to DMEC-Cys nanoparticles. CCD showed that optimized buccal film containing 4% chitosan and 10% glycerol has 5.81 kg/mm(2) tensile strength and 2.47 N bioadhesion forces. Results of ex vivo study demonstrated that permeation of insulin nanoparticles through rabbit buccal mucosa is 17.1, 67.89 and 97.18% for chitosan, DMEC and DMEC-Cys nanoparticles, respectively. Thus, this study suggests that DMEC-Cys can act as a potential enhancer for buccal delivery of insulin.

Interaction between lidocaine hydrochloride (with and without adrenaline) and various irrigants: A nuclear magnetic resonance analysis.

Science.gov (United States)

Vidhya, Nirmal; Karthikeyan, Balasubramanian Saravana; Velmurugan, Natanasabapathy; Abarajithan, Mohan; Nithyanandan, Sivasankaran

2014-05-01

Interaction between local anesthetic solution, lidocaine hydrochloride (with and without adrenaline), and root canal irrigants such as sodium hypochlorite (NaOCl), ethylene diamine tetra-acetic acid (EDTA), and chlorhexidine (CHX) has not been studied earlier. Hence, the purpose of this in vitro study was to evaluate the chemical interaction between 2% lidocaine hydrochloride (with and without adrenaline) and commonly used root canal irrigants, NaOCl, EDTA, and CHX. SAMPLES WERE DIVIDED INTO EIGHT EXPERIMENTAL GROUPS: Group I-Lidocaine hydrochloride (with adrenaline)/3% NaOCl, Group II-Lidocaine hydrochloride (with adrenaline)/17% EDTA, Group III- Lidocaine hydrochloride (with adrenaline)/2% CHX, Group IV-Lidocaine hydrochloride (without adrenaline)/3% NaOCl, Group V-Lidocaine hydrochloride (without adrenaline)/17% EDTA, Group VI-Lidocaine hydrochloride (without adrenaline)/2% CHX, and two control groups: Group VII-Lidocaine hydrochloride (with adrenaline)/deionized water and Group VIII-Lidocaine hydrochloride (without adrenaline)/deionized water. The respective solutions of various groups were mixed in equal proportions (1 ml each) and observed for precipitate formation. Chemical composition of the formed precipitate was then analysed by nuclear magnetic resonance spectroscopy (NMR) and confirmed with diazotation test. In groups I and IV, a white precipitate was observed in all the samples on mixing the respective solutions, which showed a color change to reddish brown after 15 minutes. This precipitate was then analysed by NMR spectroscopy and was observed to be 2,6-xylidine, a reported toxic compound. The experimental groups II, III, V, and VI and control groups VII and VIII showed no precipitate formation in any of the respective samples, until 2 hours. Interaction between lidocaine hydrochloride (with and without adrenaline) and NaOCl showed precipitate formation containing 2,6-xylidine, a toxic compound.

Lactic acid demineralization of shrimp shell and chitosan synthesis

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Alewo Opuada AMEH

2015-05-01

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

Measurement and correlation of solubility of cefmenoxime hydrochloride in pure solvents and binary solvent mixtures

International Nuclear Information System (INIS)

Wang, Jinxiu; Xie, Chuang; Yin, Qiuxiang; Tao, Linggang; Lv, Jun; Wang, Yongli; He, Fang; Hao, Hongxun

2016-01-01

Highlights: • Solubility of cefmenoxime hydrochloride in pure and binary solvents was determined. • The experimental solubility data were correlated by thermodynamic models. • A model was employed to calculate the melting temperature of cefmenoxime hydrochloride. • Mixing thermodynamic properties of cefmenoxime hydrochloride were calculated. - Abstract: The solubility of cefmenoxime hydrochloride in pure solvents and binary solvent mixtures was measured at temperatures from (283.15 to 313.15) K by using the UV spectroscopic method. The results reveal that the solubility of cefmenoxime hydrochloride increases with increasing temperature in all solvent selected. The solubility of cefmenoxime hydrochloride reaches its maximum value when the mole fraction of isopropanol is 0.2 in the binary solvent mixtures of (isopropanol + water). The modified Apelblat equation and the NRTL model were successfully used to correlate the experimental solubility in pure solvents while the modified Apelblat equation, the CNIBS/R–K model and the Jouyban–Acree model were applied to correlate the solubility in binary solvent mixtures. In addition, the mixing thermodynamic properties of cefmenoxime hydrochloride in different solvents were also calculated based on the NRTL model and experimental solubility data.

Functionalization of chitosan by click chemistry

Science.gov (United States)

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

2017-12-01

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

Fabrication and Characteristics of Chitosan Sponge as a Tissue Engineering Scaffold

Directory of Open Access Journals (Sweden)

Takeshi Ikeda

2014-01-01

Full Text Available Cells, growth factors, and scaffolds are the three main factors required to create a tissue-engineered construct. After the appearance of bovine spongiform encephalopathy (BSE, considerable attention has therefore been focused on nonbovine materials. In this study, we examined the properties of a chitosan porous scaffold. A porous chitosan sponge was prepared by the controlled freezing and lyophilization of different concentrations of chitosan solutions. The materials were examined by scanning electron microscopy, and the porosity, tensile strength, and basic fibroblast growth factor (bFGF release profiles from chitosan sponge were examined in vitro. The morphology of the chitosan scaffolds presented a typical microporous structure, with the pore size ranging from 50 to 200 μm. The porosity of chitosan scaffolds with different concentrations was approximately 75–85%. A decreasing tendency for porosity was observed as the concentration of the chitosan increased. The relationship between the tensile properties and chitosan concentration indicated that the ultimate tensile strength for the sponge increased with a higher concentration. The in vitro bFGF release study showed that the higher the concentration of chitosan solution became, the longer the releasing time of the bFGF from the chitosan sponge was.

Novel procedure to enhance PLA surface properties by chitosan irreversible immobilization

Science.gov (United States)

Stoleru, Elena; Dumitriu, Raluca Petronela; Munteanu, Bogdanel Silvestru; Zaharescu, Traian; Tănase, Elisabeta Elena; Mitelut, Amalia; Ailiesei, Gabriela-Liliana; Vasile, Cornelia

2016-03-01

A novel two step procedure was applied for poly(lactic acid) (PLA) functionalization consisting in the exposure to cold radiofrequency plasma in nitrogen atmosphere or to gamma irradiation followed by ;grafting to; of a chitosan layer using carbodiimide chemistry. The adhesion and stability of the deposited surface layer was assured by plasma/gamma irradiation treatment while the chitosan layer offers antifungal/antibacterial/antioxidant activities. Chitosan with different viscosities/deacetylation degree was deposited by electrospinning or immersion methods. Correlations between rheological behavior of chitosan solutions and chitosan layer deposition conditions are made. The PLA surface properties were investigated by water contact angle measurements, ATR-FTIR spectroscopy, AFM, chemiluminiscence, etc. It has been established that the surface roughness increases direct proportional with cold plasma duration and gamma irradiation dose and further increases by chitosan coating which at its turn depends on chitosan characteristics (viscosity and deacetylation degree) and method of deposition. Nano-fibers with relatively homogeneous and reproducible features are obtained by electrospinning of highly viscous chitosan while with the other two types of chitosan both microparticles and nano-fibers are formed. The chitosan coating obtained by immersion is more homogenous and compact and has a better antibacterial activity than the electrospun layer as fiber meshes.

Structural coloration of chitosan-cationized cotton fabric using photonic crystals

Science.gov (United States)

Yavuz, G.; Zille, A.; Seventekin, N.; Souto, A. P.

2017-10-01

In this work, poly (styrene-methyl methacrylate-acrylic acid) P(St-MMA-AA) composite nanospheres were deposited onto chitosan-cationized woven cotton fabrics followed by a second layer of chitosan. The deposited photonic crystals (PCs) on the fabrics were evaluated for coating efficiency and resistance, chemical analysis and color variation by optical and SEM microscopy, ATR-FTIR, diffuse reflectance spectroscopy and washing fastness. Chitosan deposition on cotton fabric provided cationic groups on the fiber surface promoting electrostatic interaction with photonic crystals. SEM images of the washed samples indicate that the PCs are firmly coated on the cotton surface only in the chitosan treated sample. The photonic nanospheres show an average diameter of 280 nm and display a face-centered cubic closepacking structure with an average thickness of 10 μm. A further chitosan post-treatment enhances color yield of the samples due to the chitosan transparent covering layer that induce bright reflections where the angles of incidence and reflection are the same. After washing, no photonic crystal can be detected on control fabric surface. However, the sample that received a chitosan post-treatment showed a good washing fastness maintaining a reasonable degree of iridescence. Chitosan fills the spaces between the polymer spheres in the matrix stabilizing the photonic structure. Sizeable variations in lattice spacing will allow color variations using more flexible non-close-packed photonic crystal arrays in chitosan hydrogels matrices.

Spectrophotometric determination of eflornithine hydrochloride ...

African Journals Online (AJOL)

Purpose: To develop and validate a spectrophotometric method for the quantitative determination of eflornithine hydrochloride as a pure compound and in pharmaceutical formulations. Methods: The method involved the reaction of the target compound with vanillin reagent at specific pH 5.6 to produce a green reddish color ...

Spectrophotometric Determination of Eflornithine Hydrochloride ...

African Journals Online (AJOL)

Purpose: To develop and validate a spectrophotometric method for the quantitative determination of eflornithine hydrochloride as a pure compound and in pharmaceutical formulations. Methods: The method involved the reaction of the target compound with vanillin reagent at specific pH. 5.6 to produce a green reddish color ...

Spectrophotometric method of the determination of gold (III) by using imipramine hydrochloride and promethazine hydrochloride

International Nuclear Information System (INIS)

Dembinski, B.; Kurzawa, M.; Szydlowska-Czerniak, A.

2003-01-01

Imipramine hydrochloride (IPM.HCl) and promethazine hydrochloride (PMT-HCl) were used for the spectrophotometric determination of gold (III) in the aqueous solution. The halides complexes of gold (III) created a coloured coupling with the studied drugs which were extractable in chloroform. These new compounds were characterized by IR,UV-VIS spectra and thermal and elemental analysis. Rapid and sensitive spectrophotometric method for the determination of gold (III) in the aqueous solution is described. The absorbance was found to be linear function of the gold (III) concentration in the range from 0.2 to 20 x10/sup -1/ mg. The ratio of complex (AuX/sub 4/) to the organic cation from drug in the obtained compounds was determined as 1:1. The method was satisfactorily applied to the analysis of gold (III). A great advantage of the proposed method is that the trace amounts of gold (III) can also be examined. (author)

Atovaquone and proguanil hydrochloride for treatment of malaria.

Science.gov (United States)

Kremsner, P G; Looareesuwan, S; Chulay, J D

1999-05-01

Safe and effective new drugs are needed for treatment of malaria. Atovaquone and proguanil hydrochloride is a new antimalarial combination that has recently become available in many countries. Data from clinical trials evaluating atovaquone/proguanil for treatment of malaria were reviewed. In 10 open-label clinical trials, treatment of uncomplicated falciparum malaria with 1000 mg atovaquone and 400 mg proguanil hydrochloride (or the equivalent based on body weight in patients proguanil has been used to provide radical cure of asymptomatic Plasmodium falciparum infections prior to initiation of placebo-controlled trials of malaria prophylaxis. Recurrent parasitemia occurred within 28 days in 0 of 99 subjects who subsequently received prophylaxis with atovaquone/proguanil and 1 of 81 subjects who subsequently received placebo. Atovaquone/proguanil is also effective for treatment of malaria caused by the other three Plasmodium species that cause malaria in humans. For treatment of vivax malaria, therapy with primaquine in addition to atovaquone/proguanil is needed to prevent relapse from latent hepatic hypnozoites. Atovaquone and proguanil hydrochloride is a safe and effective combination for treatment of malaria.