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.

Development of polyamide-6/chitosan membranes for desalination

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A. EL-Gendi

2014-06-01

Full Text Available This article deals with “developing novel polyamide-6/chitosan membranes for water desalting using wet phase inversion technique”, in which novel polyamide-6/chitosan membranes were prepared using an appropriate polymer concerning the national circumferences, along with the definition of different controlling parameters of the preparing processes and their effects on the characteristics of the produced membranes. Further, evaluation process of the fabricated sheets was undertaken. Preparation process was followed by assessment of the membrane structural characteristics; then the desalting performance of each prepared membrane was evaluated under different operating conditions in order to find the structure–property relationship. The results show that the membrane flux increases with the increase of operating pressure. The salt rejection and permeation flux have been enhanced this indicates that the chitosan (CS addition to the polyamide-6 (PA-6 membrane increases the membrane hydrophilic property. Hydraulic permeability coefficient is not stable and varies considerably with the operating pressure.

Layer-by-Layer Alginate and Fungal Chitosan Based Edible Coatings Applied to Fruit Bars.

Science.gov (United States)

Bilbao-Sainz, Cristina; Chiou, Bor-Sen; Punotai, Kaylin; Olson, Donald; Williams, Tina; Wood, Delilah; Rodov, Victor; Poverenov, Elena; McHugh, Tara

2018-05-30

Food waste is currently being generated at an increasing rate. One proposed solution would be to convert it to biopolymers for industrial applications. We recovered chitin from mushroom waste and converted it to chitosan to produce edible coatings. We then used layer-by-layer (LbL) electrostatic deposition of the polycation chitosan and the polyanion alginate to coat fruit bars enriched with ascorbic acid. The performance of the LbL coatings was compared with those containing single layers of fungal chitosan, animal origin chitosan and alginate. Bars containing alginate-chitosan LbL coatings showed increased ascorbic acid content, antioxidant capacity, firmness and fungal growth prevention during storage. Also, the origin of the chitosan did not affect the properties of the coatings. Mushroom stalk bases could be an alternative source for isolating chitosan with similar properties to animal-based chitosan. Also, layer-by-layer assembly is a cheap, simple method that can improve the quality and safety of fruit bars. © 2018 Institute of Food Technologists®.

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.

Integrating nanohybrid membranes of reduced graphene oxide: chitosan: silica sol gel with fiber optic SPR for caffeine detection

Science.gov (United States)

Kant, Ravi; Tabassum, Rana; Gupta, Banshi D.

2017-05-01

Caffeine is the most popular psychoactive drug consumed in the world for improving alertness and enhancing wakefulness. However, caffeine consumption beyond limits can result in lot of physiological complications in human beings. In this work, we report a novel detection scheme for caffeine integrating nanohybrid membranes of reduced graphene oxide (rGO) in chitosan modified silica sol gel (rGO: chitosan: silica sol gel) with fiber optic surface plasmon resonance. The chemically synthesized nanohybrid membrane forming the sensing route has been dip coated over silver coated unclad central portion of an optical fiber. The sensor works on the mechanism of modification of dielectric function of sensing layer on exposure to analyte solution which is manifested in terms of red shift in resonance wavelength. The concentration of rGO in polymer network of chitosan and silica sol gel and dipping time of the silver coated probe in the solution of nanohybrid membrane have been optimized to extricate the supreme performance of the sensor. The optimized sensing probe possesses a reasonably good sensitivity and follows an exponentially declining trend within the entire investigating range of caffeine concentration. The sensor boasts of an unparalleled limit of detection value of 1.994 nM and works well in concentration range of 0-500 nM with a response time of 16 s. The impeccable sensor methodology adopted in this work combining fiber optic SPR with nanotechnology furnishes a novel perspective for caffeine determination in commercial foodstuffs and biological fluids.

Coating effect of chitosan irradiation on performance of strawberries (Fragaria x ananassa Duchesne)

International Nuclear Information System (INIS)

Gatot Trimulyadi Rekso; Adjat Sudradjat

2016-01-01

Strawberry is a horticultural product which has high economic value, however, strawberries are easily damaged. Therefore, required proper post harvest handling for keep up the appearances of strawberries, one of them is the edible coating technique using chitosan. The purpose of this research was to maintaining the appearance of strawberry. Chitosan is irradiated at a dose of 0 kGy, 5 kGy, and 10 kGy, and then characterized. Observations were carried on for five days at room temperature including: the testing of the performance of the fruit that was observed visually and analysis of fruit weight loss. The results showed that the performance of strawberries is coating with irradiated chitosan of 10 kGy is still good. The percentage of weight loss strawberries coated with irradiated chitosan smaller than the strawberries without coating with chitosan (control). Strawberries coated with irradiated chitosan has a shelf life and weight loss better than control. (author)

Preparation of thermal-responsive chitosan-graft-N-isopropylacrylamide membranes via γ-ray irradiation

International Nuclear Information System (INIS)

Mu Qing; Fang Yue'e

2006-01-01

Poly(N-isopropylacrylamide) (PNIPAAm) has been attracting increasing attention because of its thermosensitivity. Many authors have studied the reaction of chitosan with NIPAAm, with most of the interest being focused on hydrogels. Few research programs, however, were about chitosan membranes grafted with NIPAAm monomer. In this study, a novel thermo-sensitive switching membrane was prepared by radiation-induced simultaneous grafting of NIPAAm onto chitosan membrane. Fourier transform infrared spectroscopy (FT-IR) was used to identify structure of the grafted membranes. Compared to FT-IR spectra of pristine chitosan, the new band at 1535 cm-1 in the grafted membrane was attributed to amide II of PNIPAAm. This indicated that NIPAAm was introduced onto the chitosan membrane. Surface morphology of the grafted membrane was different from the pristine chitosan membrane. The SEM images revealed cypress leaf-like structures adhered tightly to the grafted membrane surface, in comparison to smooth surface of the pristine chitosan membrane. Pure water flux measurements showed that the grafted membrane decreased with the increasing temperature, while water flux of pristine chitosan membrane was constant. It was found that the grafted membrane was sensitive to temperature. The effects of dose, dose rate and the concentration of NIPAAm on the grafting percentage were discussed. The graft yield increased with the monomer concentration and the absorbed dose. (authors)

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-12-15

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

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

International Nuclear Information System (INIS)

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

2011-01-01

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

Beeswax–chitosan emulsion coated paper with enhanced water vapor barrier efficiency

International Nuclear Information System (INIS)

Zhang, Weiwei; Xiao, Huining; Qian, Liying

2014-01-01

Graphical abstract: - Highlights: • The water vapor barrier efficiency of paper was enhanced via green-based emulsion coating. • Extremely high lipid content in the emulsion coating layer was firstly utilized to reduce WVTR in emulsion-based film. • A controlled WVTR of beeswax–chitosan emulsion coating could be obtained by dying at specific temperature. - Abstract: For lipid–hydrocolloid emulsion based film, the increase of lipid amount would improve its water vapor barrier property, but also reduce the mechanical strength of the film in the meantime thus leading to a compromised lipid content in the film. However, when the emulsion is coated on paper surface, more lipid could be used for emulsion preparation to enhance the moisture resistance without considering the weakened strength of the film induced by lipid, because the mechanical properties of emulsion coated paper is mainly governed by the strength of base paper instead of the coating layer. In this study, beeswax–chitosan emulsion was first prepared and then coated on paper surface to improve paper's water vapor barrier and water resistance properties. The range and variance analysis of orthogonal test design showed that the order of priorities of the factors accordingly was beeswax solid content, drying temperature and chitosan concentration. The effect of drying temperature on water vapor transmission rate (WVTR) and water contact angle of coated paper was further investigated using 1.2 wt% chitosan and 96% beeswax solid content in the coating layer. The results indicated that water vapor barrier property was in accordance with the density of the coating layer. Atomic force microscope (AFM) was also used to characterize the surface morphology and explain the hydrophobicity of beeswax–chitosan coated paper. It was found that surface beeswax particles melted to wrinkle at high drying temperatures, while roughness values maintained at micro-scale over the temperature range investigated

Biological evaluation of silver nanoparticles incorporated into chitosan-based membranes

NARCIS (Netherlands)

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

2017-01-01

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

Polymer Brush-Functionalized Chitosan Hydrogels as Antifouling Implant Coatings.

Science.gov (United States)

Buzzacchera, Irene; Vorobii, Mariia; Kostina, Nina Yu; de Los Santos Pereira, Andres; Riedel, Tomáš; Bruns, Michael; Ogieglo, Wojciech; Möller, Martin; Wilson, Christopher J; Rodriguez-Emmenegger, Cesar

2017-06-12

Implantable sensor devices require coatings that efficiently interface with the tissue environment to mediate biochemical analysis. In this regard, bioinspired polymer hydrogels offer an attractive and abundant source of coating materials. However, upon implantation these materials generally elicit inflammation and the foreign body reaction as a consequence of protein fouling on their surface and concomitant poor hemocompatibility. In this report we investigate a strategy to endow chitosan hydrogel coatings with antifouling properties by the grafting of polymer brushes in a "grafting-from" approach. Chitosan coatings were functionalized with polymer brushes of oligo(ethylene glycol) methyl ether methacrylate and 2-hydroxyethyl methacrylate using photoinduced single electron transfer living radical polymerization and the surfaces were thoroughly characterized by XPS, AFM, water contact angle goniometry, and in situ ellipsometry. The antifouling properties of these new bioinspired hydrogel-brush coatings were investigated by surface plasmon resonance. The influence of the modifications to the chitosan on hemocompatibility was assessed by contacting the surfaces with platelets and leukocytes. The coatings were hydrophilic and reached a thickness of up to 180 nm within 30 min of polymerization. The functionalization of the surface with polymer brushes significantly reduced the protein fouling and eliminated platelet activation and leukocyte adhesion. This methodology offers a facile route to functionalizing implantable sensor systems with antifouling coatings that improve hemocompatibility and pave the way for enhanced device integration in tissue.

Chitosan coating as an antibacterial surface for biomedical applications.

Directory of Open Access Journals (Sweden)

Mélanie D'Almeida

Full Text Available A current public health issue is preventing post-surgical complications by designing antibacterial implants. To achieve this goal, in this study we evaluated the antibacterial activity of an animal-free chitosan grafted onto a titanium alloy.Animal-free chitosan binding on the substrate was performed by covalent link via a two-step process using TriEthoxySilylPropyl Succinic Anhydride (TESPSA as the coupling agent. All grafting steps were studied and validated by means of X-ray Photoelectron Spectroscopy (XPS, Time-of-Flight secondary ion mass spectrometry (ToF-SIMS analyses and Dynamic-mode Secondary Ion Mass Spectrometry (DSIMS. The antibacterial activity against Escherichia coli and Staphylococcus aureus strains of the developed coating was assessed using the number of colony forming units (CFU.XPS showed a significant increase in the C and N atomic percentages assigned to the presence of chitosan. A thick layer of polymer deposit was detected by ToF-SIMS and the results obtained by DSIMS measurements are in agreement with ToF-SIMS and XPS analyses and confirms that the coating synthesis was a success. The developed coating was active against both gram negative and gram positive tested bacteria.The success of the chitosan immobilization was proven using the surface characterization techniques applied in this study. The coating was found to be effective against Escherichia coli and Staphylococcus aureus strains.

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

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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.

One-Step Method for Preparation of Magnetic Nanoparticles Coated with Chitosan

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Karla M. Gregorio-Jauregui

2012-01-01

Full Text Available Preparation of magnetic nanoparticles coated with chitosan in one step by the coprecipitation method in the presence of different chitosan concentrations is reported here. Obtaining of magnetic superparamagnetic nanoparticles was confirmed by X-ray diffraction and magnetic measurements. Scanning transmission electron microscopy allowed to identify spheroidal nanoparticles with around 10-11 nm in average diameter. Characterization of the products by Fourier transform infrared spectroscopy demonstrated that composite chitosan-magnetic nanoparticles were obtained. Chitosan content in obtained nanocomposites was estimated by thermogravimetric analysis. The nanocomposites were tested in Pb2+ removal from a PbCl2 aqueous solution, showing a removal efficacy up to 53.6%. This work provides a simple method for chitosan-coated nanoparticles obtaining, which could be useful for heavy metal ions removal from water.

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

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Zhang J

2017-12-01

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

Chitosan-Based Coating with Antimicrobial Agents: Preparation, Property, Mechanism, and Application Effectiveness on Fruits and Vegetables

Directory of Open Access Journals (Sweden)

Yage Xing

2016-01-01

Full Text Available Chitosan coating is beneficial to maintaining the storage quality and prolonging the shelf life of postharvest fruits and vegetables, which is always used as the carrier film for the antimicrobial agents. This review focuses on the preparation, property, mechanism, and application effectiveness on the fruits and vegetables of chitosan-based coating with antimicrobial agents. Chitosan, derived by deacetylation of chitin, is a modified and natural biopolymer as the coating material. In this article, the safety and biocompatible and antimicrobial properties of chitosan were introduced because these attributes are very important for its application. The methods to prepare the chitosan-based coating with antimicrobial agents, such as essential oils, acid, and nanoparticles, were developed by other researchers. Meanwhile, the application of chitosan-based coating is mainly due to its antimicrobial activity and other functional properties, which were investigated, introduced, and analyzed in this review. Furthermore, the surface and mechanical properties were also investigated by researchers and concluded in this article. Finally, the effects of chitosan-based coating on the storage quality, microbial safety, and shelf life of fruits and vegetables were introduced. Their results indicated that chitosan-based coating with different antimicrobial agents would probably have wide prospect in the preservation of fruits and vegetables in the future.

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

Science.gov (United States)

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

2011-12-01

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

Chitosan-coated nickel-ferrite nanoparticles as contrast agents in magnetic resonance imaging

International Nuclear Information System (INIS)

Ahmad, Tanveer; Bae, Hongsub; Iqbal, Yousaf; Rhee, Ilsu; Hong, Sungwook; Chang, Yongmin; Lee, Jaejun; Sohn, Derac

2015-01-01

We report evidence for the possible application of chitosan-coated nickel-ferrite (NiFe 2 O 4 ) nanoparticles as both T 1 and T 2 contrast agents in magnetic resonance imaging (MRI). The coating of nickel-ferrite nanoparticles with chitosan was performed simultaneously with the synthesis of the nickel-ferrite nanoparticles by a chemical co-precipitation method. The coated nanoparticles were cylindrical in shape with an average length of 17 nm and an average width of 4.4 nm. The bonding of chitosan onto the ferrite nanoparticles was confirmed by Fourier transform infrared spectroscopy. The T 1 and T 2 relaxivities were 0.858±0.04 and 1.71±0.03 mM −1 s −1 , respectively. In animal experimentation, both a 25% signal enhancement in the T 1 -weighted mage and a 71% signal loss in the T 2 -weighted image were observed. This demonstrated that chitosan-coated nickel-ferrite nanoparticles are suitable as both T 1 and T 2 contrast agents in MRI. We note that the applicability of our nanoparticles as both T 1 and T 2 contrast agents is due to their cylindrical shape, which gives rise to both inner and outer sphere processes of nanoparticles. - Highlights: • Chitosan-coated nickel-ferrite (Ni-Fe 2 O 4 ) nanoparticles were synthesized in an aqueous system by chemical co-precipitation. • The characterization of bare and chitosan-coated nanoparticles were performed using various analytical tools, such as TEM, FTIR, XRD, and VMS. • We evaluated the coated particles as potential T 1 and T 2 contrast agents for MRI by measuring T 1 and T 2 relaxation times as a function of iron concentration. • Both T 1 and T 2 effects were also observed in animal experimentation

Edible Coating Using a Chitosan-Based Colloid Incorporating Grapefruit Seed Extract for Cherry Tomato Safety and Preservation.

Science.gov (United States)

Won, Jin Sung; Lee, Seung Jo; Park, Hyeon Hwa; Song, Kyung Bin; Min, Sea C

2018-01-01

Grapefruit seed extract (GSE)-containing chitosan-based coating was developed and applied to cherry tomatoes to protect them from Salmonella invasion and improve their storability. The coating colloids were produced by mixing a chitosan colloid (1% [w/w] chitosan) with GSE at various concentrations (0.5%, 0.7%, 1.0%, and 1.2% [w/w]) using high-shear mixing (10000 rpm, 2 min). Coatings with chitosan colloids containing GSE at 0.0%, 0.5%, 0.7%, and 1.0% (w/w) inactivated Salmonella on cherry tomatoes by 1.0 ± 0.3, 1.2 ± 0.3, 1.6 ± 0.1, and 2.0 ± 0.3 log CFU/cherry tomato, respectively. Coatings both with and without GSE (1.0%) effectively inhibited the growth of Salmonella and total mesophilic aerobes, reduced CO 2 generation, and retarded titratable acidity decrease during storage at 10 and 25 °C. The advantage of incorporating GSE in the formulation was demonstrated by delayed microorganism growth and reduced weight loss at 25 °C. The chitosan-GSE coating did not affect lycopene concentration, color, and sensory properties (P > 0.05). Chitosan-GSE coating shows potential for improving the microbiological safety and storability of cherry tomatoes, with stronger efficacy at 25 °C than that of chitosan coating without GSE. A novel chitosan coating containing grape fruit seed extract (GSE) improved the microbiological safety against Salmonella and storability of cherry tomatoes without altering their flavor, demonstrating its strong potential as an effective postharvest technology. Chitosan coating containing GSE might be preferable over chitosan coating without GSE for application to tomatoes that are stored at room temperature in that it more effectively inhibits microbial growth and weight loss than the coating without GSE at 25 °C. © 2017 Institute of Food Technologists®.

Effect of gallic acid/chitosan coating on fresh pork quality in modified atmosphere packaging.

Science.gov (United States)

Fang, Zhongxiang; Lin, Daniel; Warner, Robyn Dorothy; Ha, Minh

2018-09-15

Fresh meat safety and quality is a major concern of consumers in the current food market. The objective of this research was to investigate a newly developed gallic acid/chitosan edible coating on the preservation of fresh pork quality in modified atmosphere package (MAP) stored at 4 °C. The pork loins were coated with 2% chitosan (CHI), 0.2% gallic acid in 2% chitosan (CHI/0.2G), or 0.4% gallic acid in 2% chitosan (CHI/0.4G). Results showed that the antimicrobial activity of the chitosan coating was increased with the incorporation of gallic acid. The CHI/0.2G and CHI/0.4G pork loins also had lower lipid oxidation and myoglobin oxidation. However, the CHI/0.4G sample exhibited a pro-protein oxidation effect, suggesting an optimal concentration of gallic acid should be incorporated. This research provides a practical method in application of gallic acid/chitosan coatings on preservation of fresh pork to improve the safety and quality in MAP environment. Copyright © 2018 Elsevier Ltd. All rights reserved.

Analysis of mechanical traction in biofilms chitosan and clay aiming fruits coating

Directory of Open Access Journals (Sweden)

Suliene Dantas do Nascimento

2014-12-01

Full Text Available A new concept of food packaging has been studied and developed in order to meet the application needs of the market. The application of such biofilms coating is directly related to its characteristics and possible interactions of these with the product and the environment. There is evidence that chitosan is a viable alternative to be applied in the coating for fruit characteristics antifungal, antibacterial and its direct action as a barrier to water vapor, which is the latest aging fruit. The clay, besides increasing permeability to water vapor, enables a greater adhesion of the film on the fruit surface. This paper presents the results that were obtained from the development of chitosan films aimed at applying the coating of fruit. It were made tensile test with films using different chitosan and clay concentrations. The tests followed the standards of ASTM D882/02. The best results were obtained for the coating of chitosan in 2% acetic acid, which showed a plastic strain of 4.4% and a maximum stress at rupture of 50.2 MPa. The results were lower for the films with the addition of clay; the best result was observed for this coating with chitosan to 2% clay plus 2% acetic acid, with plastic deformation of 2.9% and maximum stress at rupture 18.9 MPa.

Sulfonated chitosan and dopamine based coatings for metallic implants in contact with blood.

Science.gov (United States)

Campelo, Clayton S; Chevallier, Pascale; Vaz, Juliana M; Vieira, Rodrigo S; Mantovani, Diego

2017-03-01

Thrombosis and calcification constitute the main clinical problems when blood-interacting devices are implanted in the body. Coatings with thin polymer layers represent an acknowledged strategy to modulate interactions between the material surface and the blood environment. To ensure the implant success, at short-term the coating should limit platelets adhesion and delay the clot formation, and at long-term it should delay the calcification process. Sulfonated chitosan, if compared to native chitosan, shows the unique ability to reduce proteins adsorption, decrease thrombogenic properties and limit calcification. In this work, stainless steel surfaces, commonly used for cardiovascular applications, were coated with sulfonated chitosan, by using dopamine and PEG as anchors, and the effect of these grafted surfaces on platelet adhesion, clot formation as well as on calcification were investigated. Surface characterization techniques evidenced that the coating formation was successful, and the sulfonated chitosan grafted sample exhibited a higher roughness and hydrophilicity, if compared to native chitosan one. Moreover, sulfonated surface limited platelet activation and the process of clot formation, thus confirming its high biological performances in blood. Calcium deposits were also lower on the sulfonated chitosan sample compared to the chitosan one, thus showing that calcification was minimal in presence of sulfonate groups. In conclusion, this sulfonated-modified surface has potential to be as blood-interacting material. Copyright © 2016. Published by Elsevier B.V.

Preparation of Citric Acid Crosslinked Chitosan/Poly(Vinyl Alcohol Blend Membranes for Creatinine Transport

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Retno Ariadi Lusiana

2016-08-01

Full Text Available Preparation of membrane using crosslinking reaction between chitosan and citric acid showed that functional group modification increased the number of active carrier groups which lead to better transport capacity of the membrane. In addition, the substitution of the carboxyl group increased creatinine permeation of chitosan membrane. The transport capacity of citric acid crosslinked chitosan membrane for creatinine was found to be 6.3 mg/L. The presence of cyanocobalamin slightly hindered the transport of creatinine although compounds did not able to pass through citric acid crosslinked chitosan/poly(vinyl alcohol blend membrane, as compounds no found in the acceptor phase.

Effect of chitosan and thiolated chitosan coating on the inhibition behaviour of PIBCA nanoparticles against intestinal metallopeptidases

Energy Technology Data Exchange (ETDEWEB)

Bravo-Osuna, Irene; Vauthier, Christine; Farabollini, Alessandra; Millotti, Gioconda; Ponchel, Gilles, E-mail: gilles.ponchel@u-psud.f [UMR CNRS 8612, Universite Paris Sud, Laboratoire de Physicochimie, Faculte de Pharmacie, Pharmacotechnie et Biopharmacie (France)

2008-12-15

Surface modified nanoparticles composed of poly(isobutylcyanoacrylate) (PIBCA) cores surrounded by a chitosan and thiolated chitosan gel layer were prepared and characterized in previous works. The presence of such biopolymers on the nanoparticle surface conferred those nanosystems interesting characteristics that might partially overcome the gastrointestinal enzymatic barrier, improving the oral administration of pharmacologically active peptides. In the present work, the antiprotease behaviour of this family of core-shell nanoparticles was in vitro tested against two model metallopeptidases present in the gastrointestinal tract (GIT): Carboxypeptidase A -CP A- (luminal protease) and Leucine Aminopeptidase M -LAP M- (membrane protease). As previous step, the zinc-binding capacity of these nanoparticles was evaluated. Interestingly, an improvement of both the zinc-binding capacity and the antiprotease effect of chitosan was observed when the biopolymers (chitosan and thiolated chitosan) were used as coating component of the core-shell nanoparticles, in comparison with their behaviour in solution, thanks to the different biopolymer chains rearrangement. The presence of amino, hydroxyl and thiol groups on the nanoparticle surface promoted zinc binding and hence the inhibition of the metallopeptidases analysed. On the contrary, the occurrence of a cross-linked structure in the gel layer surrounding the PIBCA cores of thiolated formulations, due to the formation of interchain and intrachain disulphide bonds, partially limited the inhibition of the proteases. The low accessibility of cations to the active groups of the cross-linked polymeric shell was postulated as a possible explanation of this behaviour. Results obtained in this work make this family of surface-modified nanocarriers promising candidates for the successfull administration of pharmacologically active peptides and proteins by the oral route.

Chitosan-based coatings in the prevention of intravascular catheter-associated infections.

Science.gov (United States)

Mendoza, Gracia; Regiel-Futyra, Anna; Tamayo, Alejandra; Monzon, Marta; Irusta, Silvia; de Gregorio, Miguel Angel; Kyzioł, Agnieszka; Arruebo, Manuel

2018-01-01

Central venous access devices play an important role in patients with prolonged intravenous administration requirements. In the last years, the coating of these devices with bactericidal compounds has emerged as a potential tool to prevent bacterial colonization. Our study describes the modification of 3D-printed reservoirs and silicone-based catheters, mimicking central venous access devices, through different approaches including their coating with the well known biocompatible and bactericidal polymer chitosan, with the anionic polysaccharide alginate; also, plasma treated surfaces were included in the study to promote polymer adhesion. The evaluation of the antimicrobial action of those surface modifications compared to that exerted by a model antibiotic (ciprofloxacin) adsorbed on the surface of the devices was carried out. Surface characterization was developed by different methodologies and the bactericidal effects of the different coatings were assayed in an in vitro model of Staphylococcus aureus infection. Our results showed a significant reduction in the reservoir roughness (≤73%) after coating though no changes were observed for coated catheters which was also confirmed by scanning electron microscopy, pointing to the importance of the surface device topography for the successful attachment of the coating and for the subsequent development of bactericidal effects. Furthermore, the single presence of chitosan on the reservoirs was enough to fully inhibit bacterial growth exerting the same efficiency as that showed by the model antibiotic. Importantly, chitosan coating showed low cytotoxicity against human keratinocytes, human lung adenocarcinoma epithelial cells, and murine colon carcinoma cells displaying viability percentages in the range of the control samples (>95%). Chitosan-based coatings are proposed as an effective and promising solution in the prevention of microbial infections associated to medical devices.

Fish gelatin combined with chitosan coating inhibits myofibril degradation of golden pomfret (Trachinotus blochii) fillet during cold storage.

Science.gov (United States)

Feng, Xiao; Bansal, Nidhi; Yang, Hongshun

2016-06-01

Coating of gelatin and chitosan can improve fish fillet's quality, but the mechanism is not clear. Chitosan/gelatin coatings significantly prevented deterioration of golden pomfret fillet at 4 °C. Chitosan with 7.2% gelatin group showed the best effect on preserving the length of myofibril, which remained greater than 15 μm at day 17 of storage, while for control, chitosan and chitosan combined with 3.6% gelatin group, it was 5.03, 10.04 and 9.02 μm, respectively. The MALDI-TOF MS result revealed that the coatings slowed down the protein deterioration of fillet. On days 13 and 17, the myosin light chain and myoglobin in control group degraded, while the two proteins still existed in chitosan/gelatin coated groups. Overall, the chitosan with 7.2% gelatin coating had the best effect on preserving fillet's quality during storage. The coating may exert its protective effect via inhibiting myofibril degradation within fillet. Copyright © 2016 Elsevier Ltd. All rights reserved.

Formation of complexes between functionalized chitosan membranes and copper: A study by angle resolved XPS

Energy Technology Data Exchange (ETDEWEB)

Jurado-López, Belén [Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga (Spain); Vieira, Rodrigo Silveira [Chemical Engineering Department, Universidade Federal do Ceará, UFC, 60455-760 Fortaleza, CE (Brazil); Rabelo, Rodrigo Balloni; Beppu, Marisa Masumi [School of Chemical Engineering, University of Campinas, UNICAMP, P.O. Box 6066, 13081-970 Campinas, SP (Brazil); Casado, Juan [Departamento de Química-Física, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga (Spain); Rodríguez-Castellón, Enrique, E-mail: castellon@uma.es [Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga (Spain)

2017-01-01

Chitosan is a biopolymer with potential applications in various fields. Recently, it has been used for heavy metals removal like copper, due to the presence of amino and hydroxyl groups in its structure. Chitosan membranes were crosslinked with epichlorohydrin and bisoxirano and functionalized with chelating agents, such as iminodiacetic acid, aspartic acid and tris-(2-amino-ethyl) polyamine. These membranes were used for copper adsorption and the formed complexes were characterized. Thermal and crystalline properties of chitosan membranes were studied by TG-DCS and X-ray diffraction. Raman, XPS and FT-IR data confirmed that copper is linked to the modified chitosan membranes by the amino groups. The oxidation state of copper-chitosan membranes were also studied by angle resolved XPS, and by UV–Vis diffuse reflectance spectroscopy. - Highlights: • Chitosan membranes were crosslinked with epichlorohydrin and bisoxirano and functionalized with chelating agents. • The chelating agent were iminodiacetic acid, aspartic acid and tris-(2-amino-ethyl) polyamine. • The functionalized membranes were used for copper adsorption and studied by ARXPS, Raman, TG-DCS, FT-IR and XRD. • Spectroscopic data confirmed that copper is linked to the modified chitosan membranes by the amino groups.

Chitosan-coated nickel-ferrite nanoparticles as contrast agents in magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Ahmad, Tanveer [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Department of Physics, Abdul Wali Khan University, Mardan (Pakistan); Bae, Hongsub; Iqbal, Yousaf [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Rhee, Ilsu, E-mail: ilrhee@knu.ac.kr [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Hong, Sungwook [Division of Science Education, Daegu University, Gyeongsan 712-714 (Korea, Republic of); Chang, Yongmin; Lee, Jaejun [Department of Diagnostic Radiology, College of Medicine, Kyungpook National University and Hospital, Daegu 700-721 (Korea, Republic of); Sohn, Derac [Department of Physics, Hannam University, Daejon (Korea, Republic of)

2015-05-01

We report evidence for the possible application of chitosan-coated nickel-ferrite (NiFe{sub 2}O{sub 4}) nanoparticles as both T{sub 1} and T{sub 2} contrast agents in magnetic resonance imaging (MRI). The coating of nickel-ferrite nanoparticles with chitosan was performed simultaneously with the synthesis of the nickel-ferrite nanoparticles by a chemical co-precipitation method. The coated nanoparticles were cylindrical in shape with an average length of 17 nm and an average width of 4.4 nm. The bonding of chitosan onto the ferrite nanoparticles was confirmed by Fourier transform infrared spectroscopy. The T{sub 1} and T{sub 2} relaxivities were 0.858±0.04 and 1.71±0.03 mM{sup −1} s{sup −1}, respectively. In animal experimentation, both a 25% signal enhancement in the T{sub 1}-weighted mage and a 71% signal loss in the T{sub 2}-weighted image were observed. This demonstrated that chitosan-coated nickel-ferrite nanoparticles are suitable as both T{sub 1} and T{sub 2} contrast agents in MRI. We note that the applicability of our nanoparticles as both T{sub 1} and T{sub 2} contrast agents is due to their cylindrical shape, which gives rise to both inner and outer sphere processes of nanoparticles. - Highlights: • Chitosan-coated nickel-ferrite (Ni-Fe{sub 2}O{sub 4}) nanoparticles were synthesized in an aqueous system by chemical co-precipitation. • The characterization of bare and chitosan-coated nanoparticles were performed using various analytical tools, such as TEM, FTIR, XRD, and VMS. • We evaluated the coated particles as potential T{sub 1} and T{sub 2} contrast agents for MRI by measuring T{sub 1} and T{sub 2} relaxation times as a function of iron concentration. • Both T{sub 1} and T{sub 2} effects were also observed in animal experimentation.

Bacterial Growth on Chitosan-Coated Polypropylene Textile

Science.gov (United States)

Erben, D.; Hola, V.; Jaros, J.; Rahel, J.

2012-01-01

Biofouling is a problem common in all systems where microorganisms and aqueous environment meet. Prevention of biofouling is therefore important in many industrial processes. The aim of this study was to develop a method to evaluate the ability of material coating to inhibit biofilm formation. Chitosan-coated polypropylene nonwoven textile was prepared using dielectric barrier discharge plasma activation. Resistance of the textile to biofouling was then tested. First, the textile was submerged into a growth medium inoculated with green fluorescein protein labelled Pseudomonas aeruginosa. After overnight incubation at 33°C, the textile was observed using confocal laser scanning microscopy for bacterial enumeration and biofilm structure characterisation. In the second stage, the textile was used as a filter medium for prefiltered river water, and the pressure development on the in-flow side was measured to quantify the overall level of biofouling. In both cases, nontreated textile samples were used as a control. The results indicate that the chitosan coating exhibits antibacterial properties. The developed method is applicable for the evaluation of the ability to inhibit biofilm formation. PMID:23724330

Biocompatibility behavior of β–tricalcium phosphate-chitosan coatings obtained on 316L stainless steel

International Nuclear Information System (INIS)

Mina, A.; Caicedo, H.H.; Uquillas, J.A.; Aperador, W.; Gutiérrez, O.; Caicedo, J.C.

2016-01-01

Biological interfaces involve the interaction of complex macromolecular systems and other biomolecules or biomaterials. Researchers have used a combination of cell, material sciences and engineering approaches to create functional biointerfaces to help improve biological functions. Materials such as hydroxyapatite (HA), β-tricalcium phosphate (β-TCP) and chitosan are important biomaterials to be used in biomedical applications such as bone-prosthesis interfaces. In this work, it was evaluated the effect of different concentrations of chitosan on the structural, electrochemical and biocompatible properties of β-tricalcium phosphate-chitosan ((β-Ca 3 (PO 4 ) 2 )-(C 6 H 11 NO 4 )n) hybrid coatings. β–tricalcium phosphate-chitosan coatings were deposited on 316L stainless steel substrates applying 260 mA AC, an agitation velocity of 250 rpm, and temperature deposition of 60 °C. It was possible to obtain coatings of 600 μm of thickness. Structure and surface properties were analyzed by X-ray diffraction (XRD) and dispersive X-ray analysis (EDX). It was found that the arrangement of the β-TCP crystal lattice changed with increasing chitosan weight concentration, showing that the orthorhombic structure of β-TCP is under tensile stress. The electrochemical properties of β–tricalcium phosphate/chitosan (β-TCP–Ch) coatings were analyzed by electrochemical impedance spectroscopy (EIS). Cellular biocompatibility was determined by lactate dehydrogenase (LDH) cytotoxicity assay using primary chinese hamster ovary (CHO) cells. β-TCP–Ch coatings with chitosan concentrations up to 25% caused cytotoxic effects to only 5–10% of CHO cells. Obtained results showed the influence of chitosan in the structural, electrochemical, and biocompatible properties of AISI 316L Stainless Steel. Consequently, the electrochemical and cytotoxic behavior of β-TCP–Ch on 316L Stainless Steel indicated that the coatings might be a promising material in biomedical applications

Physical and Oxidative Stability of Uncoated and Chitosan-Coated Liposomes Containing Grape Seed Extract

Directory of Open Access Journals (Sweden)

Jochen Weiss

2013-08-01

Full Text Available Polyphenol-rich grape seed extract (0.1 w/w% was incorporated in liposomes (1 w/w% soy lecithin by high pressure homogenization (22,500 psi and coated with chitosan (0.1 w/w%. Primary liposomes and chitosan-coated secondary liposomes containing grape seed extract showed good physical stability during 98 days of storage. Most of the polyphenols were incorporated in the shell of the liposomes (85.4%, whereas only 7.6% of the polyphenols of grape seed extract were located in the interior of the liposomes. Coating with chitosan did not change the polyphenol content in the liposomes (86.6%. The uncoated liposomes without grape seed extract were highly prone to lipid oxidation. The cationic chitosan coating, however, improved the oxidative stability to some extent, due to its ability to repel pro-oxidant metals. Encapsulated grape seed extract showed high antioxidant activity in both primary and secondary liposomes, which may be attributed to its polyphenol content. In conclusion, the best chemical stability of liposomes can be achieved using a combination of grape seed extract and chitosan.

Surface characterization of the chitosan membrane after oxygen plasma treatment and its aging effect

International Nuclear Information System (INIS)

Wang Yingjun; Yin Shiheng; Ren Li; Zhao Lianna

2009-01-01

Chitosan has received considerable attention for biomedical applications in recent years because of its biocompatibility and biodegradability. In this paper, angle-resolved x-ray photoelectron spectroscopy (ARXPS) was carried out to investigate the chemical groups' spatial orientation on the chitosan membrane surface. Oxygen plasma treatment was also employed to improve the surface hydrophilicity of the chitosan membrane. The results of ARXPS revealed the distribution of surface polar groups, such as-OH and O=CNH 2 toward the membrane bulk, which was the origin of the chitosan membrane surface hydrophobicity. The contact angle measurements and XPS results indicated that oxygen plasma treatment can markedly improve the surface hydrophilicity and surface energy of the chitosan membrane by incorporating oxygen-containing polar groups. With the existence of the aging process, the influence of plasma treatment was not permanent, it faded with storage time. The ARXPS result discovered that the reorientation of polar functional groups generated by plasma treatment toward the membrane bulk was primarily responsible for the aging effect.

Effects of chitosan-essential oil coatings on safety and quality of fresh blueberries.

Science.gov (United States)

Sun, Xiuxiu; Narciso, Jan; Wang, Zhe; Ference, Christopher; Bai, Jinhe; Zhou, Kequan

2014-05-01

Chitosan coating plus different essential oils was developed and applied to fresh blueberries in order to find more natural treatments to preserve fresh fruit quality and safety during postharvest storage. Studies were 1st performed in vitro where wild-type Escherichia coli and Penicillium digitatum were grown in suitable media, and then subjected to 6 essential oils. Three compounds, carvacrol (CAR), cinnamaldehyde (CIN), and trans-cinnamaldehyde (ECIN) had high antimicrobial capacity and were selected for an in vivo study for postharvest storage of blueberries. The selected essential oils, 0.5% each, were added into a chitosan solution and coated on fresh blueberries. After storage at 5, 10, and 20 °C for various days, fruit firmness and microbial populations were evaluated. The chitosan coating substantially decreased bacteria and yeasts/molds on the fruit, and all 3 essential oils added to the antimicrobial activities. Further dosage experiments showed that the antimicrobial activity remained even when lowering CAR concentration to 0.1% and ECIN to 0.2%. Chitosan, CAR, and ECIN also maintained fruit firmness. Our results suggest that chitosan coatings containing essential oils are effective in extending the shelf life of fresh blueberries. Blueberries are high-value fruit with strong antioxidant capacity and other health-promoting benefits. However, microbial food safety is an increasing concern, and decay and softening limits their storability. A combination of ≥ 0.1% CAR or ≥ 0.2% ECIN with a chitosan coating effectively reduced softening of fresh berries and decay by inhibiting microbial growth. © 2014 Institute of Food Technologists®

Electrodeposition to construct free-standing chitosan/layered double hydroxides hydro-membrane for electrically triggered protein release.

Science.gov (United States)

Zhao, Pengkun; Zhao, Yanan; Xiao, Ling; Deng, Hongbing; Du, Yumin; Chen, Yun; Shi, Xiaowen

2017-10-01

In this study, we report the electrodeposition of a chitosan/layered double hydroxides (LDHs) hydro-membrane for protein release triggered by an electrical signal. The electrodeposition was performed in a chitosan and insulin loaded LDHs suspension in the absence of salt. A free-standing chitosan/LDHs hydro-membrane was generated on the electrode with improved mechanical properties, which is dramatically different from the weak hydrogel deposited in the presence of salt. The amount of LDHs in the hydro-membrane affects the optical transmittance and multilayered structure of the hybrid membrane. Compared to the weak chitosan/LDHs hydrogel, the hydro-membrane has a higher insulin loading capacity and the release of insulin is relatively slow. By biasing electrical potentials to the hydro-membrane, the release behavior of insulin can be adjusted accordingly. In addition, the chitosan/LDHs hydro-membrane showed no toxicity to cells. Our results provide a facile method to construct a chitosan/LDHs hybrid multilayered hydro-membrane and suggest the great potential of the hydro-membrane in controlled protein release. Copyright © 2017 Elsevier B.V. All rights reserved.

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

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

International Nuclear Information System (INIS)

Almeida, Tiago Luiz de

2009-03-01

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

Biocompatibility behavior of β–tricalcium phosphate-chitosan coatings obtained on 316L stainless steel

Energy Technology Data Exchange (ETDEWEB)

Mina, A. [Tribology, Powder Metallurgy and Processing of Solid Recycled Research Group, Universidad del Valle, Cali (Colombia); Caicedo, H.H. [Department of Anatomy and Cell Biology, University of Illinois at Chicago, IL, 60612 (United States); National Biotechnology & Pharmaceutical Association, Chicago, IL, 60606 (United States); Uquillas, J.A. [Universidad San Francisco de Quito USFQ, Colegio de Ciencias de la Salud COCSA, Escuela de Medicina, Hospital de los Valles, Edificio de Especialidades Médicas, Av. Interoceánica km 12 1/2 Cumbayá, Quito (Ecuador); Biomaterials Innovation Research Center, Department of Medicine, Brigham and Women' s Hospital, Harvard Medical School, Boston, MA, 02139 (United States); Aperador, W. [Departament of Engineering, Universidad Militar Nueva Granada, Bogotá (Colombia); Gutiérrez, O. [Departament of Pharmacology Universidad del Valle, Cali (Colombia); Caicedo, J.C., E-mail: julio.cesar.caicedo@correounivalle.edu.co [Tribology, Powder Metallurgy and Processing of Solid Recycled Research Group, Universidad del Valle, Cali (Colombia)

2016-06-01

Biological interfaces involve the interaction of complex macromolecular systems and other biomolecules or biomaterials. Researchers have used a combination of cell, material sciences and engineering approaches to create functional biointerfaces to help improve biological functions. Materials such as hydroxyapatite (HA), β-tricalcium phosphate (β-TCP) and chitosan are important biomaterials to be used in biomedical applications such as bone-prosthesis interfaces. In this work, it was evaluated the effect of different concentrations of chitosan on the structural, electrochemical and biocompatible properties of β-tricalcium phosphate-chitosan ((β-Ca{sub 3}(PO{sub 4}){sub 2})-(C{sub 6}H{sub 11}NO{sub 4})n) hybrid coatings. β–tricalcium phosphate-chitosan coatings were deposited on 316L stainless steel substrates applying 260 mA AC, an agitation velocity of 250 rpm, and temperature deposition of 60 °C. It was possible to obtain coatings of 600 μm of thickness. Structure and surface properties were analyzed by X-ray diffraction (XRD) and dispersive X-ray analysis (EDX). It was found that the arrangement of the β-TCP crystal lattice changed with increasing chitosan weight concentration, showing that the orthorhombic structure of β-TCP is under tensile stress. The electrochemical properties of β–tricalcium phosphate/chitosan (β-TCP–Ch) coatings were analyzed by electrochemical impedance spectroscopy (EIS). Cellular biocompatibility was determined by lactate dehydrogenase (LDH) cytotoxicity assay using primary chinese hamster ovary (CHO) cells. β-TCP–Ch coatings with chitosan concentrations up to 25% caused cytotoxic effects to only 5–10% of CHO cells. Obtained results showed the influence of chitosan in the structural, electrochemical, and biocompatible properties of AISI 316L Stainless Steel. Consequently, the electrochemical and cytotoxic behavior of β-TCP–Ch on 316L Stainless Steel indicated that the coatings might be a promising material in

Antimicrobial activity of chitosan coatings and films against Listeria monocytogenes on black radish.

Science.gov (United States)

Jovanović, Gordana D; Klaus, Anita S; Nikšić, Miomir P

2016-01-01

The antibacterial activity of chitosan coatings prepared with acetic or lactic acid, as well as of composite chitosan-gelatin films prepared with essential oils, was evaluated in fresh shredded black radish samples inoculated with Listeria monocytogenes ATCC 19115 and L. monocytogenes ATCC 19112 during seven days of storage at 4°C. The chitosan coating prepared with acetic acid showed the most effective antibacterial activity. All tested formulations of chitosan films exhibited strong antimicrobial activity on the growth of L. monocytogenes on black radish, although a higher inhibition of pathogens was achieved at higher concentrations of chitosan. The antimicrobial effect of chitosan films was even more pronounced with the addition of essential oils. Chitosan-gelatin films with thyme essential oils showed the most effective antimicrobial activity. A reduction of 2.4log10CFU/g for L. monocytogenes ATCC 19115 and 2.1log10CFU/g for L. monocytogenes ATCC 19112 was achieved in the presence of 1% chitosan film containing 0.2% of thyme essential oil after 24h of storage. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Diatomite reinforced chitosan composite membrane as potential scaffold for guided bone regeneration.

Science.gov (United States)

Tamburaci, Sedef; Tihminlioglu, Funda

2017-11-01

In this study, natural silica source, diatomite, incorporated novel chitosan based composite membranes were fabricated and characterized for bone tissue engineering applications as possible bone regeneration membrane. The effect of diatomite loading on the mechanical, morphological, chemical, thermal and surface properties, wettability and in vitro cytotoxicity and cell proliferation on of composite membranes were investigated and observed by tensile test, atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), protein adsorption assay, air/water contact angle analysis and WST-1 respectively. Swelling studies were also performed by water absorption capacity determination. Results showed that incorporation of diatomite to the chitosan matrix increased the surface roughness, swelling capacity and tensile modulus of membranes. An increase of about 52% in Young's modulus was achieved for 10wt% diatomite composite membranes compared with chitosan membranes. High cell viability results were obtained with indirect extraction method. Besides, in vitro cell proliferation and ALP activity results showed that diatom incorporation significantly increased the ALP activity of Saos-2 cells cultured on chitosan membranes. The novel composite membranes prepared in the present study with tunable properties can be considered as a potential candidate as a scaffold in view of its enhanced physical & chemical properties as well as biological activities for bone tissue engineering applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Chitosan-58S bioactive glass nanocomposite coatings on TiO2 nanotube: Structural and biological properties

Science.gov (United States)

Mokhtari, H.; Ghasemi, Z.; Kharaziha, M.; Karimzadeh, F.; Alihosseini, F.

2018-05-01

Bacterial infection and insignificant osseointegration have been recognized as the main reasons of the failures of titanium based implants. The aim of this study was to apply titanium oxide nanotube (TNT) array on titanium using electrochemical anodization process as a more appropriate substrate for chitosan and chitosan-58S bioactive glass (BG) (58S-BG-Chitosan) nanocomposite coatings covered TNTs (TNT/Chiosan, TNT/58S-BG-Chitosan, respectively) through a conventional dip-coating process. Results showed that a TNT layer with average inner diameter of 82 ± 19 nm and wall's thickness of 23 ± 9 nm was developed on titanium surface using electrochemical anodization process. Roughness and contact angle measurement showed that TNT with Ra = 449 nm had highest roughness and hydrophilicity which then reduced to 86 nm and 143 nm for TNT/Chitosan and TNT/58S-BG-Chitosan, respectively. In vitro bioactivity evaluation in simulated buffer fluid (SBF) solution and antibacterial activity assay predicted that TNT/58S-BG-Chitosan was superior in bone like apatite formation and antibacterial activity against both gram-positive and gram-negative bacteria compared to Ti, TNT and TNT/Chitosan samples, respectively. Results revealed the noticeable MG63 cell attachment and proliferation on TNT/58S-BG-Chitosan coating compared to those of uncoated TNTs. These results confirmed the positive effect of using TNT substrate for natural polymer coating on improved bioactivity of implant.

Surface characterization and corrosion behavior of micro-arc oxidized Ti surface modified with hydrothermal treatment and chitosan coating

International Nuclear Information System (INIS)

Neupane, Madhav Prasad; Park, Il Song; Lee, Min Ho

2014-01-01

In the present work, we describe the surface modification of commercially pure titanium (CP-Ti) by a composite/multilayer coating approach for biomedical applications. CP-Ti samples were treated by micro-arc oxidation (MAO) and subsequently some of the samples were coated with chitosan (Chi) by dip coating method, while others were subjected to hydrothermal treatment (HT) followed by chitosan coating. The MAO, MAO/Chi, and MAO/HT/Chi coated Ti were characterized and their characteristics were compared with CP-Ti. X-ray diffraction and scanning electron microscopy were used to assess the structural and morphological characteristics. The average surface roughness was determined using a surface profilometer. The corrosion resistance of untreated and surface modified Ti in commercial saline at 298 K was evaluated by potentiodynamic polarization test. The results indicated that the chitosan coating is very well integrated with the MAO and MAO/HT coating by physically interlocking itself with the coated layer and almost sealed all the pores. The surface roughness of hydrothermally treated and chitosan coated MAO film was superior evidently to that with other sample groups. The corrosion studies demonstrated that the MAO, hydrothermally treated and chitosan coated sample enhanced the corrosion resistance of titanium. The result indicates that fabrication of hydrothermally treated MAO surface coatings with chitosan is a significant approach to protect the titanium from corrosion, hence enhancing the potential use of titanium as bio-implants. - Highlights: • Micro-arc oxidized (MAO) and hydrothermally treated (HT) Ti surfaces are coated with chitosan (Chi). • The MAO/HT/Chi surface exhibits pores sealing and enhanced the surface roughness. • The MAO/HT/Chi surface significantly increase the corrosion resistance. • The MAO/HT/Chi can be a potential surface of titanium for bio-implants

Mechanochemistry of Chitosan-Coated Zinc Sulfide (ZnS) Nanocrystals for Bio-imaging Applications

Science.gov (United States)

Bujňáková, Zdenka; Dutková, Erika; Kello, Martin; Mojžiš, Ján; Baláž, Matej; Baláž, Peter; Shpotyuk, Oleh

2017-05-01

The ZnS nanocrystals were prepared in chitosan solution (0.1 wt.%) using a wet ultra-fine milling. The obtained suspension was stable and reached high value of zeta potential (+57 mV). The changes in FTIR spectrum confirmed the successful surface coating of ZnS nanoparticles by chitosan. The prepared ZnS nanocrystals possessed interesting optical properties verified in vitro. Four cancer cells were selected (CaCo-2, HCT116, HeLa, and MCF-7), and after their treatment with the nanosuspension, the distribution of ZnS in the cells was studied using a fluorescence microscope. The particles were clearly seen; they passed through the cell membrane and accumulated in cytosol. The biological activity of the cells was not influenced by nanoparticles, they did not cause cell death, and only the granularity of cells was increased as a consequence of cellular uptake. These results confirm the potential of ZnS nanocrystals using in bio-imaging applications.

Effects of Edible Chitosan Coating on Quality and Increasing Storage Life of Cucumber cv.

Directory of Open Access Journals (Sweden)

M. Ghasemi Tavallaiy

2015-06-01

Full Text Available Chitosan, is non-toxic, biodegradable and biocompatible material, which can be used as edible coatings to maintain quality and enhance postharvest life of fruits and vegetables. In this study, the effect of chitosan at 0, 0.5, 1 and 2% concentrations on storage life of cucumber cv. "Zomorod" was investigated. After treatment and keeping in an incubator at 12 °C and 90% relative humidity, the fruits were assessed in 5-days intervals to determine parameters such as firmness, weight loss, vitamin C, titratable acidity, soluble solids and chlorophyll content. Experiment was performed as a split-plot design in time in a completely randomized design with three replications. The results of the experiment showed that chitosan coating, had a significant effect on all traits except titrable acidity. The lowest weight loss and the highest firmness were recorded with 1% chitosan treatment which significantly differed from the control. It is appeared that chitosan coatings could be used to increase the storage life of cucumber fruit and to maintain its quality for a longer period.

The shelf life extension of refrigerated grass carp (Ctenopharyngodon idellus) fillets by chitosan coating combined with glycerol monolaurate.

Science.gov (United States)

Yu, Dawei; Jiang, Qixing; Xu, Yanshun; Xia, Wenshui

2017-08-01

A novel chitosan-based coating solution was prepared by combining glycerol monolaurate (GML) for shelf life extension of refrigerated grass carp fillets. The control and coated fillets were analyzed periodically for physicochemical (pH, thiobarbituric acid (TBA) value, total volatile basic nitrogen (TVB-N) value, K value, and shear force), microbiological (total viable counts (TVC), psychrophilic bacteria counts (PTC), Pseudomonads and H 2 S-producing bacteria) and sensorial characteristics. The results showed that chitosan-GML coated samples presented better quality preservation effects than chitosan coating alone. In addition, 2% chitosan enriched with 0.3% GML showed the significant (Pchitosan coating enriched with GML was a promising method to extend the shelf life of refrigerated fillets. Copyright © 2017. Published by Elsevier B.V.

Effect of chitosan-carvacrol coating on the quality of Pacific white shrimp during iced storage as affected by caprylic acid.

Science.gov (United States)

Wang, Qianyun; Lei, Jun; Ma, Junjie; Yuan, Gaofeng; Sun, Haiyan

2018-01-01

This study aimed to investigate the effect of chitosan-carvacrol coating with or without caprylic acid (CAP) on the quality of Pacific white shrimp (Litopenaeus vannamei) during 10days of iced storage. The result showed that chitosan-carvacrol coating significantly inhibited the increase in total aerobic plate count (TPC), pH and total volatile basic nitrogen content (TVB-N) of shrimp in comparison with the control. Chitosan-carvacrol coating also delayed the melanosis formation and changes of ΔE values, and improved the texture and sensory properties of shrimp. Moreover, incorporation of CAP potentiated the efficacy of chitosan-carvacrol coating in retarding the increase of TPC and TVB-N. Incorporation of CAP into chitosan-carvacrol coating also enabled the texture characteristics of shrimp to be retained greater degrees. These results suggested that chitosan-carvacrol coating may be promising to be used as active packaging for extending the shelf life, and incorporation of CAP may enhance the efficacy of the coating. Copyright © 2017 Elsevier B.V. All rights reserved.

Long-term antibiotic delivery by chitosan-based composite coatings with bone regenerative potential

Science.gov (United States)

Ordikhani, F.; Simchi, A.

2014-10-01

Composite coatings with bone-bioactivity and drug-eluting capacity are considered as promising materials for titanium bone implants. In this work, drug-eluting chitosan-bioactive glass coatings were fabricated by a single-step electrophoretic deposition technique. Drug-loading and -releasing capacity of the composite coatings were carried out using the vancomycin antibiotic. Uniform coatings with a thickness of ∼55 μm containing 23.7 wt% bioactive glass particles and various amounts of the antibiotic (380-630 μg/cm2) were produced. The coatings were bioactive in terms of apatite-forming ability in simulated body fluid and showed favorable cell adhesion and growth. In vitro biological tests also indicated that the composite coatings had better cellular affinity than pristine chitosan coatings. The in vitro elution kinetics of the composite coating revealed an initial burst release of around 40% of the drug within the first elution step of 1 h and following by a continuous eluting over 4 weeks, revealing long-term drug-delivering potential. Antibacterial tests using survival assay against Gram-positive Staphylococcus aureus bacteria determined the effect of vancomycin release on reduction of infection risk. Almost no bacteria were survived on the coatings prepared from the EPD suspension containing ≥0.5 g/l vancomycin. The developed chitosan-based composite coatings with bone bioactivity and long-term drug-delivery ability may be potentially useful for metallic implants to reduce infection risk.

Differences between Solution and Membrane Forms of Chitosan on the In Vitro Activity of Fibroblasts

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Bahar Uslu

2015-03-01

Full Text Available Background: Chitosan, a linear polysaccharide, has been recently used in biomedical applications. In vitro studies have demonstrated its effect on cellular growth and its stimulatory action on cellular layer formation. Aims: The present study aims to compare the proliferative effects of chitosan in two forms, membranous and solution forms, on Swiss 3T3 mouse embryonic fibroblasts. Study Design: In vitro study. Methods: Three experimental groups were formed: cells were cultured in a normal medium without chitosan (Control Group; cells were cultured either in a medium containing 2.0% chitosan in membranous form (Membrane Group or chitosan solution at a concentration of 2.0% (Solution Group.Two different methods were used in the experiments: cells cultured on the medium containing chitosan in solution or membranous forms (method 1; and chitosan solution or membranous forms were added into the medium containing previously cultured cells (method 2. Results: Scanning electron microscopic investigations of the experimental groups revealed cells with well-defined cellular projections, intact cellular membranes and tight intercellular junctions. They were especially prominent in the membrane group of method 1 and in the membrane and solution groups of method 2. Mouse monoclonal anti-collagen 1 primary antibody was used to indicate collagen synthesis. Prominent collagen synthesis was detected in the membrane groups on the 10th day of culture for both methods. Bromodeoxyuridine (BrdU and MTT assays were performed in order to assess cellular proliferation and viability, respectively. BrdU labelling tests indicated a higher proliferation index in the membrane group of method 1 on the 5th and 10th days. For the second method, the membranous form on the 10th day and solution form on the 5th day were the most effective groups in terms of cellular proliferation. MTT results reflected a high cellular viability in method 1 on the 5th day of treatment with the

Effects of chitosan-coated fibers as a scaffold for three-dimensional cultures of rabbit fibroblasts for ligament tissue engineering.

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Sarukawa, Junichiro; Takahashi, Masaaki; Abe, Masashi; Suzuki, Daisuke; Tokura, Seiichi; Furuike, Tetsuya; Tamura, Hiroshi

2011-01-01

Material selection in tissue-engineering scaffolds is one of the primary factors defining cellular response and matrix formation. In this study, we fabricated chitosan-coated poly(lactic acid) (PLA) fiber scaffolds to test our hypothesis that PLA fibers coated with chitosan highly promoted cell supporting properties compared to those without chitosan. Both PLA fibers (PLA group) and chitosan-coated PLA fibers (PLA-chitosan group) were fabricated for this study. Anterior cruciate ligament (ACL) fibroblasts were isolated from Japanese white rabbits and cultured on scaffolds consisting of each type of fiber. The effects of cell adhesivity, proliferation, and synthesis of the extracellular matrix (ECM) for each fiber were analyzed by cell counting, hydroxyproline assay, scanning electron microscopy and quantitative RT-PCR. Cell adhesivity, proliferation, hydroxyproline content and the expression of type-I collagen mRNA were significantly higher in the PLA-chitosan group than in the PLA group. Scanning electron microscopic observation showed that fibroblasts proliferated with a high level of ECM synthesis around the cells. Chitosan coating improved ACL fibroblast adhesion and proliferation, and had a positive effect on matrix production. Thus, the advantages of chitosan-coated PLA fibers show them to be a suitable biomaterial for ACL tissue-engineering scaffolds.

Surface-modified Y zeolite-filled chitosan membrane for direct methanol fuel cell

Energy Technology Data Exchange (ETDEWEB)

Wu, Hong; Zheng, Bin; Zheng, Xiaohong; Wang, Jingtao; Yuan, Weikang; Jiang, Zhongyi [Key Laboratory for Green Chemical Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China)

2007-11-15

Hybrid membranes composed of chitosan (CS) as organic matrix and surface-modified Y zeolite as inorganic filler are prepared and their applicability for DMFC is demonstrated by methanol permeability, proton conductivity and swelling property. Y zeolite is modified using silane coupling agents, 3-aminopropyl-triethoxysilane (APTES) and 3-mercaptopropyl-trimethoxysilane (MPTMS), to improve the organic-inorganic interfacial morphology. The mercapto group on MPTMS-modified Y zeolite is further oxidized into sulfonic group. Then, the resultant surface-modified Y zeolites with either aminopropyl groups or sulfonicpropyl groups are mixed with chitosan in acetic acid solution and cast into membranes. The transitional phase generated between chitosan matrix and zeolite filler reduces or even eliminates the nonselective voids commonly exist at the interface. The hybrid membranes exhibit a significant reduction in methanol permeability compared with pure chitosan and Nafion117 membranes, and this reduction extent becomes more pronounced with the increase of methanol concentration. By introducing -SO{sub 3}H groups onto zeolite surface, the conductivity of hybrid membranes is increased up to 2.58 x 10{sup -2} S cm{sup -1}. In terms of the overall selectivity index ({beta} = {sigma}/P), the hybrid membrane is comparable with Nafion117 at low methanol concentration (2 mol L{sup -1}) and much better (three times) at high methanol concentration (12 mol L{sup -1}). (author)

Effects of a Chitosan Coating Layer on the Surface Properties and Barrier Properties of Kraft Paper

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Shanhui Wang

2016-01-01

Full Text Available Biodegradable chitosan can be applied as a coating on the surface of kraft paper in order to improve its barrier properties against water vapor and air. The food packaging industry can benefit from the addition of chitosan to its current packaging, and in turn reduce pollution from plastic packaging plants. This paper discusses the film formation of chitosan, the permeability of paper coated with a chitosan layer, and the influence on the paper’s surface and barrier properties under different process conditions. SEM (scanning electron microscope, AFM (atomic force microscope, ATR-FTIR (Fourier transmission infrared spectroscope with attenuated total reflection, and PDA (penetration dynamics analysis were used to analyze the properties of chitosan’s film formation and permeability. A controlled experiment showed that the chitosan layer was smoother than the surface of the uncoated kraft paper, had better film formation, and that there was no chitosan penetration through the kraft paper. The barrier properties against water vapor were strongest when there was a higher concentration of chitosan solution at the optimum pH, stirring speed, and those with a thicker coating on the kraft paper.

Effect of Chitosan Coating Containing Active Agents on Microbial Growth, Rancidity and Moisture Loss of Meatball During Storage

OpenAIRE

Pranoto, Yudi; Rakshit, Sudip Kumar

2008-01-01

Edible coatings based on chitosan were applied on meatball product in order to preserve quality during storages atambient and refrigeration temperatures. To improve its efficacy, chitosan coatings were incorporated with garlic oil0.2%, potassium sorbate 0.1 % and nisin 51,000 IU. The qualities of meatball assessed were total microbial growth, TBA value and percentage of moisture loss. All chitosan coatings suppressed microbial growth in meatball and strong- ly revealed when stored at refriger...

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

International Nuclear Information System (INIS)

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

2013-01-01

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. - Highlights: • Synthesised N,O-carboxymethyl chitosan (NOCs) coated alginate (ALg) microspheres. • Their effect on intestinal microflora was investigated in simulated gastric juices. • NOCs A coated ALg microspheres improved Bifidobacterium longum survival in SGJ. • The modified chitosan layer improved the pH-response of alginate microspheres. • NOCs A coated microspheres could be used to deliver oral bioactive compounds

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

Energy Technology Data Exchange (ETDEWEB)

Mi, Yu; Su, Ran [Shaanxi R and D Center of Biomaterials and Fermentation Engineering, School of Chemical Engineering, Northwest University (China); Fan, Dai-Di, E-mail: fandaidi@nwu.edu.cn [Shaanxi R and D Center of Biomaterials and Fermentation Engineering, School of Chemical Engineering, Northwest University (China); Zhu, Xiao-Li [Shaanxi R and D Center of Biomaterials and Fermentation Engineering, School of Urban and Environmental Science, Northwest University, Taibai North Road 229, Xi' an, Shaanxi 710069 (China); Zhang, Wen-Ni [Shaanxi R and D Center of Biomaterials and Fermentation Engineering, School of Chemical Engineering, Northwest University (China); Shaanxi Key Laboratory of Degradable Biomedical Materials, School of Chemical Engineering, Northwest University (China)

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. - Highlights: • Synthesised N,O-carboxymethyl chitosan (NOCs) coated alginate (ALg) microspheres. • Their effect on intestinal microflora was investigated in simulated gastric juices. • NOCs A coated ALg microspheres improved Bifidobacterium longum survival in SGJ. • The modified chitosan layer improved the pH-response of alginate microspheres. • NOCs A coated microspheres could be used to deliver oral bioactive compounds.

Preparation and characterization of chitosan-silver/hydroxyapatite composite coatings onTiO{sub 2} nanotube for biomedical applications

Energy Technology Data Exchange (ETDEWEB)

Yan, Yajing [Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China); Zhang, Xuejiao [Medical Informatics, Hebei North University, Zhangjiakou 075000 (China); Li, Caixia [Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China); Huang, Yong [Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China); College of Lab Medicine, Hebei North University, Zhangjiakou 075000 (China); Ding, Qiongqiong [Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China); Pang, Xiaofeng, E-mail: xfpang@aliyun.com [Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China)

2015-03-30

Highlights: • Chitosan/silver-doped hydroxyapatite biocomposite coating was successfully deposited on anodized Ti by electrochemical deposition. • The chemical state of silver in the synthesized coatings was studied by XPS peak deconvolution. • The synthesized coatings have excellent antibacterial activity because of synergistic effect of the Ag and CS. • The CSAgHAp coatings showed good biocompatibility and no adverse effect in cell culture tests. - Abstract: A biocomposite coating containing chitosan, silver, and hydroxyapatite was developed on anodized titanium substrate by electrochemical deposition. Coatings were characterized by field-emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and polarisation studies. Results showed that the prepared coatings had compact and dense morphology with a thickness of 6.2 ± 0.7 μm and that silver was evenly distributed. Testing the prepared coatings with Gram-positive and Gram-negative bacterial strains exhibited antibacterial activity because of the synergistic effect of silver and chitosan. The prepared coatings were also found to be nontoxic to MC3T3-E1 cells. These results suggested that chitosan/silver-hydroxyapatite biocomposite coatings can prevent the bacterial infection of implants.

Carbon-based sputtered coatings for enhanced chitosan-based films properties

Science.gov (United States)

Fernandes, C.; Calderon V., S.; Ballesteros, Lina F.; Cerqueira, Miguel A.; Pastrana, L. M.; Teixeira, José A.; Ferreira, P. J.; Carvalho, S.

2018-03-01

In order to make bio-based packaging materials competitive in comparison to petroleum-based one, some of their properties need to be improved, among which gas permeability is of crucial importance. Thus, in this work, carbon-based coatings were applied on chitosan-based films by radiofrequency reactive magnetron sputtering aiming to improve their barrier properties. Chemical and morphological properties were evaluated in order to determine the effect of the coatings on the chemical structure, surface hydrophobicity and barrier properties of the system. Chemical analysis, performed by electron energy loss spectroscopy and Fourier transform infrared spectroscopy, suggests similar chemical characteristics among all coatings although higher incorporation of hydrogen as the acetylene flux increases was observed. On the other hand, scanning transmission electron microscopy revealed that the porosity of the carbon layer can be tailored by the acetylene flux. More importantly, the chitosan oxygen permeability showed a monotonic reduction as a function of the acetylene flux. This study opens up new opportunities to apply nanostructured coatings on bio-based polymer for enhanced oxygen barrier properties.

Chitosan Cross-linked Reconstituted Amniotic Collagen Membrane ...

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Chitosan Cross-linked Reconstituted Amniotic Collagen Membrane – An Excellent Cell Substratum. The KERATINOCYTE proliferation and Differentiation into multiple layers is due to the presence of type - IV collagen in the amnion. Cultured FIBROBLASTS had good ...

Protein-adsorption and Ca-phosphate formation on chitosan-bioactive glass composite coatings

Science.gov (United States)

Wagener, V.; Boccaccini, A. R.; Virtanen, S.

2017-09-01

In the last years, chitosan-bioactive glass (BG) composites have been developed and investigated as bioactive coatings for orthopedic applications. The increase of bioactivity occurs due to the stimulation of calcium-phosphate/hydroxyapatite formation on the surface while the coating is degrading. In the present work, protein adsorption and its influence on calcium-phosphate precipitation was studied for the first time on such composite coatings. The experiments involved coating of 316L stainless steel substrates with chitosan (Ch) and chitosan-bioactive glass (Ch-BG) and immersion of the coated samples in two different bovine serum albumin (BSA) containing solutions, namely DI H2O (with pH adjusted to about 7.2 with diluted NaOH) and simulated body fluid (SBF). In order to investigate the influence of protein adsorption on calcium-phosphate precipitation, samples were also immersed in DI H2O and in SBF without BSA. Samples were analyzed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Surface analysis revealed that adsorption of BSA takes place on all studied samples and that protein adsorption is influenced by the presence of Ca2+ and PO43- ions. Bioactivity in the form of hydroxyapatite pre-stage formation is significantly increased on Ch-BG composite coating as compared with bare stainless steel surface. However, calcium-phosphate precipitation in SBF is reduced by the presence of BSA.

Effect of concentration of Curcuma longa L. on chitosan-starch based edible coating

Science.gov (United States)

Yusof, N. M.; Jai, J.; Hamzah, F.; Yahya, A.; Pinijsuwan, S.

2017-08-01

The ability of chitosan-starch based coating to extend shelf life of strawberry were studied. The main objectives of this paper is to study the effects of different concentrations (20, 15, 10 and 5 µL) of Curcuma longa L. (CUR) essential oil into chitosan-based edible coating on surface tension in order to increase the effectiveness of the coating. CUR or turmeric is one of the commercially planted herbs in Malaysia for its phytochemical benefits. Application of edible coating using dipping technique has been analysed and evaluated for their effectiveness in extending shelf life of fruits. Surface tension was analysed to investigate the adhesion properties. The best CUR concentration was 15 µL with the optimum surface tension was found to be 31.92 dynes/cm.

Physico-mechanical and structural properties of eggshell membrane gelatin- chitosan blend edible films

DEFF Research Database (Denmark)

Mohammadi, Reza; Mohammadifar, Mohammad Amin; Rouhi, Milad

2018-01-01

This study investigated the physico-mechanical and structural properties of composite edible films based on eggshell membrane gelatin (G) and chitosan (Ch) (75G:25Ch, 50G:50Ch, 25G:75Ch). The results demonstrated that the addition of Ch increased elongation at break significantly (p< 0.05), but r......This study investigated the physico-mechanical and structural properties of composite edible films based on eggshell membrane gelatin (G) and chitosan (Ch) (75G:25Ch, 50G:50Ch, 25G:75Ch). The results demonstrated that the addition of Ch increased elongation at break significantly (p... interactions introduced by the addition of chitosan to eggshell membrane gelatin as new resources could improve the films’ functional properties....

Structure, apatite inducing ability, and corrosion behavior of chitosan/halloysite nanotube coatings prepared by electrophoretic deposition on titanium substrate.

Science.gov (United States)

Molaei, A; Amadeh, A; Yari, M; Reza Afshar, M

2016-02-01

In this study chitosan/halloysite nanotube composite (CS/HNT) coatings were deposited by electrophoretic deposition (EPD) on titanium substrate. Using HNT particles were investigated as new substituents for carbon nanotubes (CNTs) in chitosan matrix coatings. The ability of chitosan as a stabilizing, charging, and blending agent for HNT particles was exploited. Furthermore, the effects of pH, electrophoretic bath, and sonicating duration were studied on the deposition of suspensions containing HNT particles. Microstructure properties of coatings showed uniform distribution of HNT particles in chitosan matrix to form smooth nanocomposite coatings. The zeta potential results revealed that at pH around 3 there is an isoelectric point for HNT and it would have cathodic and anionic states at pH values less and more than 3, respectively. Therefore, CS/HNT composite deposits were produced in the pH range of 2.5 to 3. The apatite inducing ability of chitosan-HNT composite coating assigned that HNT particles were biocompatible because they formed carbonated hydroxyapatite particles on CS/HNT coating in corrected simulated body fluid (C-SBF). Finally, electrochemical corrosion characterizations determined that corrosion resistance in CS/HNT coating has been improved compared to bare titanium substrate. Copyright © 2015 Elsevier B.V. All rights reserved.

Light-Addressed Electrodeposition of Enzyme-Entrapped Chitosan Membranes for Multiplexed Enzyme-Based Bioassays Using a Digital Micromirror Device

Directory of Open Access Journals (Sweden)

Yeu-Long Jiang

2013-08-01

Full Text Available This paper describes a light-addressed electrolytic system used to perform an electrodeposition of enzyme-entrapped chitosan membranes for multiplexed enzyme-based bioassays using a digital micromirror device (DMD. In this system, a patterned light illumination is projected onto a photoconductive substrate serving as a photo-cathode to electrolytically produce hydroxide ions, which leads to an increased pH gradient. The high pH generated at the cathode can cause a local gelation of chitosan through sol-gel transition. By controlling the illumination pattern on the DMD, a light-addressed electrodeposition of chitosan membranes with different shapes and sizes, as well as multiplexed micropatterning, was performed. The effect of the illumination time of the light pattern on the dimensional resolution of chitosan membrane formation was examined experimentally. Moreover, multiplexed enzyme-based bioassay of enzyme-entrapped chitosan membranes was also successfully demonstrated through the electrodeposition of the chitosan membranes with various shapes/sizes and entrapping different enzymes. As a model experiment, glucose and ethanol were simultaneously detected in a single detection chamber without cross-talk using shape-coded chitosan membranes entrapped with glucose oxidase (GOX, peroxidase (POD, and Amplex Red (AmR or alcohol oxidase (AOX, POD, and AmR by using same fluorescence indicator (AmR.

Effect of the addition CNTs on performance of CaP/chitosan/coating deposited on magnesium alloy by electrophoretic deposition

Energy Technology Data Exchange (ETDEWEB)

Zhang, Jie [Department of Neuro Intern, First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China); Pharmaceutical Research Institute in Heilongjiang Province, Jiamusi University, Jiamusi 154007 (China); Wen, Zhaohui, E-mail: wenzhaohui1968@163.com [Department of Neuro Intern, First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China); Zhao, Meng [Department of Neuro Intern, First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China); Li, Guozhong, E-mail: hydlgz1962@163.com [Department of Neuro Intern, First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China); Dai, Changsong, E-mail: changsd@hit.edu.cn [School of Chemistry Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China)

2016-01-01

CaP/chitosan/carbon nanotubes (CNTs) coating on AZ91D magnesium alloy was prepared via electrophoretic deposition (EPD) followed by conversion in a phosphate buffer solution (PBS). The bonding between the layer and the substrate was studied by an automatic scratch instrument. The phase compositions and microstructures of the composite coatings were determined by using X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), Raman spectroscopy and scanning electron microscope (SEM). The element concentration and gentamicin concentration were respectively determined by inductively coupled plasma optical emission spectrometer (ICP-OES) test and ultraviolet spectrophotometer (UV). The cell counting kit (CCK) assay was used to evaluate the cytotoxicity of samples to SaOS-2 cells. The results showed that a few CNTs with their original tubular morphology could be found in the CaP/chitosan coating and they were beneficial for the crystal growth of phosphate and improvement of the coating bonding when the addition amount of CNTs in 500 ml of electrophoretic solution was from 0.05 g to 0.125 g. The loading amount of gentamicin increased and the releasing speed of gentamicin decreased after CNTs was added into the CaP/chitosan coating for immersion loading and EPD loading. The cell viability of Mg based CaP/chitosan/CNTs was higher than that of Mg based CaP/chitosan from 16 days to 90 days. - Highlights: • CaP/chitosan/CNTs coating on AZ91D was prepared. • The addition of CNTs could improve the performance of CaP/chitosan coating. • A new method of loading gentamicin by EPD was proposed.

The Effect of UVC Irradiation on the Mechanical Properties of Chitosan Membrane in Sterilization Process

Science.gov (United States)

Rupiasih, N. N.; Sumadiyasa, M.; Putra, I. K.

2018-04-01

The present study, we report about the effect of UVC irradiation on the mechanical properties of chitosan membrane in the sterilization process. The membrane used was chitosan membrane 2% which prepared by a casting method using chitosan as matrix and acetic acid 1% as a solvent. The UVC source used was germicidal ultraviolet (UVG) which widely used for sterilization purposes. Variation doses were done by the varying time of irradiation, e.g. 5 min, 15 min, 30 min, and 60 min. Those samples are named as S1, S2, S3, and S4, respectively. Chitosan membrane before irradiation namely S0 also used for comparative study. The effect of UVC irradiation on the mechanical properties of membranes has been examined by different techniques including FTIR, DMA, and the water uptake capability. The results showed that ultimate tensile strength (UTS) and moduli of elasticity (E) were increased by increasing the irradiation time. From FTIR analysis obtained that no new molecules were formed in irradiated membranes. The water uptakes capability of the membranes after irradiation was smaller compared with before irradiation, and among the irradiated membranes, the water uptake capabilities were increased by increasing the exposure time. These observations suggested that more care should be taken during the sterilization process and outdoor used of the membrane. The other side, the UVC irradiation can improve the mechanical properties of the membranes.

Effect of functional chitosan coating and gamma irradiation on the shelf-life of chicken meat during refrigerated storage

Science.gov (United States)

Hassanzadeh, Parviz; Tajik, Hossein; Rohani, Seyed Mehdi Razavi; Moradi, Mehran; Hashemi, Mohammad; Aliakbarlu, Javad

2017-12-01

The present study was conducted to evaluate the combined effect of low-dose gamma irradiation (2.5 kGy) and chitosan edible coating (2%) containing grape seed extract (GSE) (0.1%) on the microbial, chemical and sensorial quality of chicken breast meat during 21 days of storage at 4 °C. The samples were periodically analyzed for microbiological (aerobic mesophilic and psychrotrophic counts), chemical (TBA, pH, aw) and sensorial (odor, appearance, and overall acceptability) characteristics. Results indicated that irradiation and the active coating had significant (P ≤ 0.05) effects on reduction of bacterial growth with at least a 14-day extension of shelf life. Results represented the protective effect of chitosan coating containing GSE against induced lipid oxidation by irradiation. All chitosan-coated samples showed lower TBA and pH values than other treatments during storage, and no significant (P > 0.05) difference was observed due to irradiation in TBA values. Results also indicated that the application of chitosan coating significantly improved the sensorial quality of the samples, and none of the evaluated sensorial attributes was significantly affected by irradiation. Based on the results obtained in this study, the application of low-dose gamma irradiation and chitosan coating containing GSE was effective in preserving the quality of fresh chicken meats and is recommended in meat products.

New type of chitosan/2-hydroxypropyl-β-cyclodextrin composite membrane for gallic acid encapsulation and controlled release.

Science.gov (United States)

Paun, Gabriela; Neagu, Elena; Tache, Andreia; Radu, G L

2014-01-01

A new type of chitosan/2-hydroxypropyl-β-cyclodextrin composite membrane have been developed for the encapsulation and controlled release of gallic acid. The morphology of the composite membrane was investigated by infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM), whereas swelling gallic acid and release properties were investigated by UV-visible spectroscopy. The release behavior with pH changes was also explored. The composite membrane based on chitosan/2-hydroxypropyl-β-cyclodextrin with gallic acid included showed improved antioxidant capacities compared to plain chitosan membrane. The information obtained in this study will facilitate the design and preparation of composite membrane based on chitosan and could open a wide range of applications, particularly its use as an antioxidant in food, food packaging, biomedical (biodegradable soft porous scaffolds for enhance the surrounding tissue regeneration), pharmaceutical and cosmetics industries.

Effect of Chitosan Coating with Cinnamon Oil on the Quality and Physiological Attributes of China Jujube Fruits

Science.gov (United States)

Xing, Yage; Lin, Hongbin; Cao, Dong; Xu, Qinglian; Han, Wenfeng; Wang, Ranran; Che, Zhenming; Li, Xihong

2015-01-01

Effects of chitosan coating with cinnamon oil on the physiological attributes and preservation quality of China jujube fruits during storage at 4°C for 60 days were investigated. Results indicated that weight loss and decay of jujube fruits were significantly reduced by chitosan-oil coating during the period of 60-day storage, which also exhibited a quite beneficial effect on maintaining the sensory quality for jujube fruits. Meanwhile, the contents of vitamin C and titratable acid decreased to 3.08 mg·g−1 and 0.342% for the fruits treated by chitosan-oil coating (1.0% + 0.10%), respectively. Polyphenol oxidase, superoxide dismutase, and peroxidase activities were 13.40 U·g−1, 14.53 U·g−1, and 63.6 U·g−1 at the end of storage, respectively. The contents of total soluble phenolics and MDA were 34.51 mg·g−1 and 19.43 μmol·g−1 for the combined coating treated samples and control fruits, respectively. These results suggested that the chitosan-oil coating might be recognized as one efficiency technology on the preservation quality of jujube fruits during the storage time. PMID:26495315

Application of Palm Stearin-Chitosan Edible Coating on Star Fruits (Averrhoa carambola L.)

International Nuclear Information System (INIS)

Nurul Hanani Mohamad Zaki; Halimahton Zahrah Mohamed Som; Zaibunnisa Abdul Haiyee

2012-01-01

An edible coating comprising of hydrophilic (chitosan) and hydrophobic (palm stearin) components which demonstrated gas barrier and moisture barrier properties respectively, was developed to prolong the post harvest life of star fruits (Averrhoa carambola L.). The physicochemical properties of the coated star fruits were evaluated in terms of weight loss, firmness, visual appearance, colour and glossiness, respiratory gases (oxygen and carbon dioxide) concentrations and ethylene concentration during storage at chilled temperature for 40 days. The results obtained showed that coating reduced weight loss, and maintained firmness and appearance of star fruits. Formulation 1:1 (chitosan:stearin) prevented decline in oxygen production, slowed down carbon dioxide production, and maintained firmness of star fruits. Visual appearance of star fruits showed that coating had lengthened the post harvest life of star fruits up to 40 days with no sign of mould growth. (author)

Chitosan-coated magnetite nanoparticles as adsorbent for the removal of molybdenum ions

International Nuclear Information System (INIS)

Sousa, Jose S.; Egute, Nayara S.; Yamaura, Mitiko; Freitas, Antonio A.; Holland, Helber; Lugao, Ademar B.

2011-01-01

Metal ions in wastewater, even at low concentrations, affect a large number of organisms due to their high degree of toxicity. Research has developed some alternative methods for metal removal from the wastewater, as adsorption using a bio sorbent of combined chitosan with magnetic particles. Chitosan is a natural bio polymer, which has a highly reactive active sites in its structure, composed of amino and hydroxyl groups with affinity to bind to metal ions. In this study, magnetic nanoparticles of coated magnetite with chitosan as an adsorbent of molybdenum(Vi) ions in aqueous medium was investigated. The adsorption experiments were performed varying the time contact from 5 to 150 min, the p H from 0.5 to 11 and the molybdenum concentrations in nitric solutions. All molybdenum analyses were carried out by gamma spectroscopy using a Hp Ge detector and 99 Mo as radioactive tracer. Results showed that the chitosan-coated magnetite particles are good adsorbent for Mo ions from aqueous medium in the range of p H from 0.5 to 9 with a removal higher than 99%. Among the studied isotherm models, the Freundlich model fitted best the equilibrium adsorption isotherm of Mo(VI) ions. (author)

An Investigation of Chitosan-Grafted-Poly(vinyl alcohol) as an Electrolyte Membrane

OpenAIRE

Panu Danwanichakul; Pongchayont Sirikhajornnam

2013-01-01

The membrane of chitosan-grafted-poly(vinyl alcohol)/poly(vinyl alcohol) (CS-g-PVA/PVA) was investigated along with chitosan (CS), PVA, CS/PVA, and Nafion 117 membranes for transport properties of water and methanol, mechanical properties, and ionic conductivity. The ionic conductivity, σ, of the crosslinked CS-g-PVA/PVA membrane was about 4.37 mS cm−1 and the methanol permeability, PS, was 1.8×10−7 cm2s−1. These gave the selectivity, σ/PS, of 23.95 mS·s·cm−3 compared with 16.35 mS·s·cm−3 of ...

Biocompatibility assessment of porous chitosan-Nafion and chitosan-PTFE composites in vivo.

Science.gov (United States)

Liu, Bo-Ji; Ma, Li-Nan; Su, Juan; Jing, Wei-Wei; Wei, Min-Jie; Sha, Xian-Zheng

2014-06-01

Chitosan (CS) is widely used as a scaffold material in tissue engineering. The objective of this study was to test whether porous chitosan membrane (PCSM) coating for Nafion used in implantable sensor reduced fibrous capsule (FC) density and promoted superior vascularization compared with PCSM coating for polytetrafluoroethylene (PTFE). PCSM was fabricated with solvent casting/particulate leaching method using silica gel as porogen and characterized in vitro. Then, PCSM-Nafion and PCSM-PTFE composites were assembled with hydrated PCSM and implanted subcutaneously in rats. The histological analysis was performed in comparison with Nafion and PTFE. Implants were explanted 35, 65, and 100 days after the implantation. Histological assessments indicated that both composites achieved presumed effects of porous coatings on decreasing collagen deposition and promoting angiogenesis. PCSM-PTFE exerted higher collagen deposition by area ratio, both within and outside, compared with that of PCSM-Nafion. Angiogenesis within and outside the PCSM-Nafion both increased over time, but that of the PCSM-PTFE within decreased. Copyright © 2013 Wiley Periodicals, Inc.

Post-harvest conservation of organic strawberries coated with cassava starch and chitosan

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Raquel P Campos

2011-10-01

Full Text Available The strawberry is as non-climacteric fruit, but has a high post-harvest respiration rate, which leads to a rapid deterioration at room temperature. This study aimed to evaluate the application of biodegradable coating on postharvest conservation of organic strawberries, cv. Camarosa, packed in plastic hinged boxes and stored at 10ºC. The treatments consisted of: a control; b 2% cassava starch; c 1% chitosan; and d 2% cassava starch + 1% chitosan. Physical and chemical characteristics of fruits were evaluated at 3, 6 and 9 days of storage, and microbiological and sensory analyses were carried out at the end of the storage period. The treatments influenced positively the post-harvest quality of organic strawberries. The coating cassava starch + chitosan provided the best results, with less than 6% of loss in fruit mass, lower counts of yeast and psychrophilic microorganisms and the best appearance according to the sensory analysis.

Effect of MWCNT Filler on Properties and Flux of Chitosan/ PEG based Nanocomposites Membranes

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Khoerunnisa Fitri

2018-01-01

Full Text Available Biopolymer are expected to be environmentally compatible and to have great potential application as membranes material. The chitosan-poly (ethylene glycol/PEG based composite membranes was successfully synthesized via inversed phase method. The effect of multiwalled carbon nanotubes (MWCNT as nanofiller on properties and performances of composite membranes were intensively evaluated. The membrane was prepared by mixing of chitosan and PEG solutions at the same composition ratio while MWCNT amount in the mixture was varied. The synthesized membrane was characterized by means of FTIR spectroscopy, scanning electron microscopy (SEM, contact angle, and tensile strength measurement. The performance of composite membrane on filtration was evaluated in term of flux (permeability and rejection (rejection tests. The results showed that the optimum volume ratio of composite membrane solution was found at 30:10:7.5 for chitosan/ PEG/ MWCNT, respectively, as indicated by the largest flux. Insertion of MWCNT nanofiller notably enhanced hydrophilicity, porosity, and mechanical properties of composites membranes that are confirmed by contact angle, SEM images and elongation forces value, respectively. The MWCNT nanofiller remarkably increased both of flux and rejection of composite membranes up to 60 Lm2h-1 and 96%, respectively. The remarkable enhancement of composite membrane performance is attributed to the effective interaction of MWCNT with polymeric matrix.

Synthesis and characterization of nontoxic chitosan-coated Fe3O4 particles for patulin adsorption in a juice-pH simulation aqueous.

Science.gov (United States)

Luo, Ying; Zhou, Zhengkun; Yue, Tianli

2017-04-15

Chitosan-coated Fe 3 O 4 particles were prepared as a magnetic adsorbent by reverse oil-in-water micro-emulsion system using Triton X-100 as the emulsifier. Coating chitosan onto the magnetic particles was confirmed by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectra and magnetic measurements. Chitosan-coated Fe 3 O 4 adsorbent was shown to be effective for patulin adsorption with a maximum adsorption capacity of 6.67mg/g within 5h by adding 300μg adsorbents into 10mL 200μg/L patulin aqueous. In addition, the recovery rate of chitosan-coated Fe 3 O 4 adsorbent reached to 99.95% within 60min, showed its excellent recoverable performance. Moreover, in vitro cytotoxicity and acute toxicity evaluation were also conducted, the results suggested that the chitosan-coated Fe 3 O 4 adsorbent was non-cytotoxic, and had no toxic response or histopathological changes on mice. The results of this study demonstrated that chitosan-coated Fe 3 O 4 particles are promising adsorbents for patulin removal in fruit juice industry. Copyright © 2016 Elsevier Ltd. All rights reserved.

Chemical, biochemical, and microbiological aspects of chitosan quaternary salt as active coating on sliced apples

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Douglas de Britto

2012-09-01

Full Text Available The biocompatibility of chitosan and chitosan quaternary salt coatings was evaluated for use as edible coatings for sliced apple. Measurement of water loss, color change, and fungal growth appearance were monitored as a function of time. A significant brownish effect was observed on chitosan coated slices, varying greatly from L* = 76.5 and Hue angle = 95.9° (t = 0 to L* = 45.3 and Hue angle = 69.8° (t = 3 days, whilst for TMC coated samples the variation was considerable lower (L* = 74.1; Hue angle = 95.0° to (L* = 67.0; Hue angle = 83.8° within the same period. The hydrosoluble derivative N,N,N-trimethylchitosan demonstrated good antifungal activity against P. expansum although highly dependent on the polymer properties such as degree of quaternization. The most efficient formulation was that prepared from derivative having a degree of quaternization of 45%, high solubility, and high viscosity. This formulation restrained fungus spreading up to 30%, while for the control it reached almost 80% of the total assessed surfaces during 7 days of storage.

Cinnamon Oil and Chitosan Coating on Orthopaedic Implant Surface for Prevention of Staphylococcus Epidermidis Biofilm Formation

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R Magetsari

2014-11-01

Full Text Available S. Epidermidis is among the most frequently isolated microorganisms found in -infection related to implanted devices and the formation of biofilm will be more resistantcompared to the planktonic form. This study was carried out determine the effect of coating on stainless steel orthopaedic implants surfaces with cinnamon oil and chitosan as bioadhesive to prevent biofilms formation of S. Epidermidis.The rod shaped stainless steel 316 L orthopaedic implant with 5 mm diameters was coated 2 times using a mixture of cinnamon oil and chitosan 3% and 2% respectively with serial concentration of cinnamon from 0.125% to 2%. The coated implants were then put into tubes that contained bacterial suspension and incubated. Subsequently, the implants were washed with PBS solution followed by MTT soulution and isopropanol acid solution that related to biofilm formation. The results were expressed in numbers which represents the absorbance level at ELISA readings on 575 nm (A575 wavelength.The stainless steel implant coated with chitosan and cinnamon oil 2% and 1% has lower absorbance level compared with the absorbance level of S.Epidermidis biofilm only. This study showed that mixture of cinnamon oil and chitosan coated on the surface of stainless steel orthopaedic implant has an effect against S.Epidermidis biofilm formation with minimum cinnamon oil concentration of 1%.

Enhanced attachment and growth of periodontal cells on glycine-arginine-glycine-aspartic modified chitosan membranes

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Hsiao-Pei Tu

2016-01-01

Full Text Available Background: Chitosan, a polymeric carbohydrate derived from the exoskeleton of arthropod, has been suggested to be an excellent biomaterial for improving wound healing, especially for bones. To improve the periodontal cell attachment and growth, the cell adhesive peptide glycine-arginine-glycine-aspartic acid (Gly-Arg-Gly-Asp, GRGD grafted chitosan membrane was introduced in this study. Materials and Methods: Two types of commercial chitosan, three types of primary cultured cells, and two established cell lines were used. Human gingival and periodontal fibroblasts (hGF and hPDL, human root derived cell (hRDC, and rat calvaria bone cell (rCalB were cultured on the GRGD-fixed by ultraviolet light photochemical method on the chitosan membrane. With (3-[4,5-dimethylthiazol-2-yl]-5-[3-carboxymethoxyphenyl]-2-[4-sulfophenyl]-2H-tetrazolium assay and propidium iodine (PI staining, the cell adhesion and growth on GRGD-grafted chitosan were examined. Basal mRNA expressions of the receptors for GRGD, integrin αv (ITG αv and ITG β3, in the human gingival fibroblast cell line and mouse osteoblast cell line (MC3T3-E1 were examined with real-time polymerase chain reaction. Results: Because the cell adhesion/growth patterns on two chitosan membranes were similar, the GRGD modification was performed on one membrane (Primex only. For periodontal cells (hGFs, hPDLs, and hRDCs, the number of attached cells were increased on the membrane with the high concentration of GRGD than those on the membrane unmodified or modified with low concentration GRGD. For rCalBs cells, a different pattern was noted: GRGD modification did not enhance the calvaria cells attachment or growth. Moreover, mRNA expressions of ITG αv and β3 in AG09319 cells were significantly higher than those in MC3T3-E1 cells. Conclusions: With the limitation of this study, we suggested that GRGD-modified chitosan, especially at high concentration, could enhance the growth of various periodontal

Chitosan-coated Stainless Steel Screws for Fixation in Contaminated Fractures

OpenAIRE

Greene, Alex H.; Bumgardner, Joel D.; Yang, Yunzhi; Moseley, Jon; Haggard, Warren O.

2008-01-01

Stainless steel screws and other internal fixation devices are used routinely to stabilize bacteria-contaminated bone fractures from multiple injury mechanisms. In this preliminary study, we hypothesize that a chitosan coating either unloaded or loaded with an antibiotic, gentamicin, could lessen or prevent these devices from becoming an initial nidus for infection. The questions investigated for this hypothesis were: (1) how much of the sterilized coating remains on the screw with simulated ...

Multi-membrane chitosan hydrogels as chondrocytic cell bioreactors.

Science.gov (United States)

Ladet, S G; Tahiri, K; Montembault, A S; Domard, A J; Corvol, M-T M

2011-08-01

We investigated the bioactivity of new chitosan-based multi-membrane hydrogel (MMH) architectures towards chondrocyte-like cells. The microstructure of the hydrogels constituting the membranes precludes any living cell penetration, whereas their lower scale architecture allows the protein diffusion. The biological behavior of chondrocytes implanted within the MMH inter-membrane spaces was studied for 45 days in culture. Chondrocytes formed cell aggregates and proliferated without loosing their chondrogenic phenotype as illustrated by collagen II and aggrecan expressions at the mRNA and protein levels. Cells produced neo-formed alcyan blue matrix proteins filling MMH interspaces. The HiF-2α/SOX9 pattern of expression suggested that the elevated chondrocytic phenotype in MMH could be related to a better hypoxic local environment than in classical culture conditions. Pro-inflammatory markers were not expressed during the period of culture. The low level of nitric oxide accumulation within the inter-membrane spaces and in the incubation medium implied that chitosan consumed nitrites produced by entrapped chondrocytes, in relation with the decrease of its molecular weight of 50%. Our data suggest that MMH structures may be considered as complex chondrocytic cell bioreactors; "active decoys of biological media", potentially promising for various biomedical applications like the inter-vertebral disk replacement. Copyright © 2011 Elsevier Ltd. All rights reserved.

Chitosan-coated magnetic nanoparticles prepared in one step by reverse microemulsion precipitation.

Science.gov (United States)

López, Raúl G; Pineda, María G; Hurtado, Gilberto; León, Ramón Díaz de; Fernández, Salvador; Saade, Hened; Bueno, Darío

2013-09-27

Chitosan-coated magnetic nanoparticles (CMNP) were obtained at 70 °C and 80 °C in a one-step method, which comprises precipitation in reverse microemulsion in the presence of low chitosan concentration in the aqueous phase. X-ray diffractometry showed that CMNP obtained at both temperatures contain a mixture of magnetite and maghemite nanoparticles with ≈4.5 nm in average diameter, determined by electron microscopy, which suggests that precipitation temperature does not affect the particle size. The chitosan coating on nanoparticles was inferred from Fourier transform infrared spectrometry measurements; furthermore, the carbon concentration in the nanoparticles allowed an estimation of chitosan content in CMNP of 6%-7%. CMNP exhibit a superparamagnetic behavior with relatively high final magnetization values (≈49-53 emu/g) at 20 kOe and room temperature, probably due to a higher magnetite content in the mixture of magnetic nanoparticles. In addition, a slight direct effect of precipitation temperature on magnetization was identified, which was ascribed to a possible higher degree of nanoparticles crystallinity as temperature at which they are obtained increases. Tested for Pb2+ removal from a Pb(NO3)2 aqueous solution, CMNP showed a recovery efficacy of 100%, which makes them attractive for using in heavy metals ion removal from waste water.

Inhibition of Listeria monocytogenes ATCC 19115 on ham steak by tea bioactive compounds incorporated into chitosan-coated plastic films

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Vodnar Dan C

2012-07-01

Full Text Available Abstract Background The consumer demands for better quality and safety of food products have given rise to the development and implementation of edible films. The use of antimicrobial films can be a promising tool for controlling L. monocytogenes on ready to eat products. The aim of this study was to develop effective antimicrobial films incorporating bioactive compounds from green and black teas into chitosan, for controlling L. monocytogenes ATCC 19115 on vacuum-packaged ham steak. The effectiveness of these antimicrobial films was evaluated at room temperature (20°C for 10 days and at refrigerated temperature (4°C for 8 weeks. Results The HPLC results clearly show that relative concentrations of catechins and caffeine in green tea ranked EGCG>EGC>CAF>ECG>EC>C while in black tea extracts ranked CAF>EGCG>ECG>EGC>EC>C. The chitosan-coated plastic films incorporating green tea and black tea extracts shows specific markers identified by FTIR. Incorporating natural extracts into chitosan showed that the growth of L monocytogenes ATCC 19115 was inhibited. The efficacy of antimicrobial effect of tea extracts incorporated into chitosan-coated plastic film was dose dependent. However, chitosan-coated films without addition of tea extracts did not inhibit the growth of L. monocytogenes ATCC 19115. Chitosan-coated plastic films incorporating 4% Green tea extract was the most effective antimicrobial, reducing the initial counts from 3.2 to 2.65 log CFU/cm2 during room temperature storage and from 3.2 to 1–1.5 log CFU/cm2 during refrigerated storage. Conclusions Incorporation of tea extracts into the chitosan-coated films considerably enhanced their effectiveness against L. monocytogenes ATCC 19115. 4% Green tea incorporated into chitosan-coated plastic film had a better antilisterial effect than 2% green tea or 2% and 4% black tea. Data from this study would provide new formulation options for developing antimicrobial packaging films using tea

Mechanically stable antimicrobial chitosan-PVA-silver nanocomposite coatings deposited on titanium implants.

Science.gov (United States)

Mishra, Sandeep K; Ferreira, J M F; Kannan, S

2015-05-05

Bionanocomposite coatings with antimicrobial activity comprising polyvinyl alcohol (PVA)-capped silver nanoparticles embedded in chitosan (CS) matrix were developed by a green soft chemistry synthesis route. Colloidal sols of PVA-capped silver nanoparticles (AgNPs) were synthesized by microwave irradiating an aqueous solution comprising silver nitrate and PVA. The bionanocomposites were prepared by adding an aqueous solution of chitosan to the synthesized PVA-capped AgNPs sols in appropriate ratios. Uniform bionanocomposite coatings with different contents of PVA-capped AgNPs were deposited onto titanium substrates by "spread casting" followed by solvent evaporation. Nanoindentation and antimicrobial activity tests performed on CS and bionanocomposites revealed that the incorporation of PVA-capped AgNPs enhanced the overall functional properties of the coatings, namely their mechanical stability and bactericidal activity against Escherichia coli and Staphylococcus aureus. The coated specimens maintained their antimicrobial activity for 8h due to the slow sustained release of silver ions. The overall benefits for the relevant functional properties of the coatings were shown increase with increasing contents of PVA-capped AgNPs in the bionanocomposites. Copyright © 2015 Elsevier Ltd. All rights reserved.

Chitosan/CNTs green nanocomposite membrane: Synthesis, swelling and polyaromatic hydrocarbons removal

International Nuclear Information System (INIS)

Bibi, Saira; Yasin, Tariq; Hassan, Safia; Riaz, Muhammad; Nawaz, Mohsan

2015-01-01

Carbon nanotubes (CNTs) were irradiated in air at 100 kGy under gamma radiations. The Raman spectroscopy of γ-treated CNTs showed distinctive changes in the absorption bands. The CNTs were mixed with blend of chitosan (Cs)/poly (vinyl alcohol) (PVA) and crosslinked with silane. The chemical reactions between the components affected the position and intensities of the infrared bands. Scanning electron micrograph of Cs/CNTs nanocomposite membrane showed the homogeneous dispersion of CNTs in the polymer matrix. The addition of CNTs lowered its swelling in water. Naphthalene (NAPH) was selected as a model compound and its removal was studied using HPLC technique. This membrane showed fast uptake of NAPH and 87% was removed from water within 30 min. The NAPH loaded membrane showed strong chemical interactions and cannot be desorbed. The fast uptake of PAHs and the green nature of this membrane made them suitable candidates for clean-up purposes. - Highlights: • Radiation modified CNTs and chitosan gave nanocomposite membranes. • This membrane showed hydrogel properties. • This membrane was used for the removal of naphthalene. • The green nature made them suitable candidates for clean-up purposes of PAH

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

Science.gov (United States)

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

2018-04-01

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

Chitosan-Coated Magnetic Nanoparticles Prepared in One Step by Reverse Microemulsion Precipitation

OpenAIRE

Hened Saade; Salvador Fernández; Ramón Díaz de León; Gilberto Hurtado; María G. Pineda; Raúl G. López; Darío Bueno

2013-01-01

Chitosan-coated magnetic nanoparticles (CMNP) were obtained at 70 ?C and 80 ?C in a one-step method, which comprises precipitation in reverse microemulsion in the presence of low chitosan concentration in the aqueous phase. X-ray diffractometry showed that CMNP obtained at both temperatures contain a mixture of magnetite and maghemite nanoparticles with ?4.5 nm in average diameter, determined by electron microscopy, which suggests that precipitation temperature does not affect the particle si...

Chitosan/(polyvinyl alcohol)/zeolite electrospun composite nanofibrous membrane for adsorption of Cr{sup 6+}, Fe{sup 3+} and Ni{sup 2+}

Energy Technology Data Exchange (ETDEWEB)

Habiba, Umma; Afifi, Amalina M.; Salleh, Areisman; Ang, Bee Chin, E-mail: amelynang@um.edu.my

2017-01-15

Highlights: • Chitosan/PVA/zeolite nanofibrous composite membrane was prepared by electrospinning method as a new chitosan based composite membrane. • The notable property of the resulting nanofibrous composite membrane is the rigidity and no weight loss in distilled water, basic and acidic medium. • Heavy metal removal effectiveness reaches to almost 100%, as the initial concentration of heavy metal is 10–20 mg/L. • The kinetic rate of adsorption is very high. • The reusability of the chitosan/PVA/zeolite nanofibrous membrane is an important finding of the current study. - Abstract: In this study, chitosan/polyvinyl alcohol (PVA)/zeolite nanofibrous composite membrane was fabricated via electrospinning. First, crude chitosan was hydrolyzed with NaOH for 24 h. Afterward, hydrolyzed chitosan solution was blended with aqueous PVA solution in different weight ratios. Morphological analysis of chitosan/PVA electrospun nanofiber showed a defect-free nanofiber material with 50:50 weight ratio of chitosan/PVA. Subsequently, 1 wt.% of zeolite was added to this blended solution of 50:50 chitosan/PVA. The resulting nanofiber was characterized with field emission scanning electron microscopy, X-Ray diffraction, Fourier transform infrared spectroscopy, swelling test, and adsorption test. Fine, bead-free nanofiber with homogeneous nanofiber was electrospun. The resulting membrane was stable in distilled water, acidic, and basic media in 20 days. Moreover, the adsorption ability of nanofibrous membrane was studied over Cr (VI), Fe (III), and Ni (II) ions using Langmuir isotherm. Kinetic parameters were estimated using the Lagergren first-order, pseudo-second-order, and intraparticle diffusion kinetic models. Kinetic study showed that adsorption rate was high. However, the resulting nanofiber membrane showed less adsorption capacity at high concentration. The adsorption capacity of nanofiber was unaltered after five recycling runs, which indicated the reusability of

Dielectric and biochemical response of a PLA-PGA-HAp-Chitosan-Collagen coated on Ti6Al4V

International Nuclear Information System (INIS)

Montanez Superlano, Nerly Deyanira; Pena Ballesteros, Dario Yesid; Estupinan Duran, Hugo Armando

2016-01-01

The interaction of a polymeric biomaterial with a culture medium and osteoblast cells, electrodeposited on Ti6Al4V was evaluated. The compound is integrated of polylactic acid-polyglycolic acid-hydroxyapatite, modified with collagen and chitosan. The relative permittivity data embodied in a dielectric impedance spectrum identified the alpha and beta dispersions related to the ion exchange and the polarization of the cell membrane was calculated. Adhesion and cell proliferation was analyzed by epifluorescence microscopy, where it was observed on the third day of the cell culture process represented by mitosis core condensation and separation of the chromosomes. The surface morphology by SEM (Scanning Electron Microscope) and AFM (Atomic Force Microscope) biomaterial was observed and cellular activity was assessed by measuring alkaline phosphatase. Finally the best surface for adhesion and cell growth was found by statistical analysis, which corresponded to the coating with the highest concentration of chitosan and collagen

Synthesis and Characterization of Chitosan Coated Manganese Zinc Ferrite Nanoparticles as MRI Contrast Agents

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M. Zahraei

2015-04-01

Full Text Available Manganese zinc ferrite nanoparticles (MZF NPs were synthesized by using a direct, efficient and environmental friendly hydrothermal method. To improve the colloidal stability of MZF NPs for biomedical applications, NPs were coated with chitosan by ionic gelation technique using sodium tripolyphosphate (TPP as crosslinker. The synthesized NPs were characterized by X ray diffraction (XRD analysis, inductively coupled plasma optical emission spectrometry (ICP-OES, fourier transform infrared (FTIR spectroscopy, transmission electron microscopy (TEM, vibrating sample magnetometer (VSM and the dynamic light scattering (DLS methods. The results confirmed the spinel ferrite phase formation without any calcination process after synthesis. Mean particle size of bare NPs was around 14 nm. Moreover, certain molar ratio of chitosan to TPP was required for encapsulation of NPs in chitosan. Coated NPs showed hydrodynamic size of 300 nm and polydispersity index about 0.3.

Chitosan/bioactive glass nanoparticle composite membranes for periodontal regeneration

NARCIS (Netherlands)

Mota, J.; Yu, N.; Caridade, S.G.; Luz, G.M.; Gomes, M.E.R.; Reis, R.L.; Jansen, J.A.; Walboomers, X.F.; Mano, J.F.

2012-01-01

Barrier membranes are used in periodontal applications with the aim of supporting periodontal regeneration by physically blocking migration of epithelial cells. The present work proposes a combination of chitosan (CHT) with bioactive glass nanoparticles (BG-NPs) in order to produce a novel guided

An Investigation of Chitosan-Grafted-Poly(vinyl alcohol as an Electrolyte Membrane

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Panu Danwanichakul

2013-01-01

Full Text Available The membrane of chitosan-grafted-poly(vinyl alcohol/poly(vinyl alcohol (CS-g-PVA/PVA was investigated along with chitosan (CS, PVA, CS/PVA, and Nafion 117 membranes for transport properties of water and methanol, mechanical properties, and ionic conductivity. The ionic conductivity, σ, of the crosslinked CS-g-PVA/PVA membrane was about 4.37 mS cm−1 and the methanol permeability, PS, was 1.8×10−7 cm2s−1. These gave the selectivity, σ/PS, of 23.95 mS·s·cm−3 compared with 16.35 mS·s·cm−3 of Nafion 117 membrane. The conductivity of the crosslinked CS-g-PVA/PVA membrane was greater than others including Nafion 117 when the membranes were saturated with methanol solution of which concentration was greater than 20%. This fact and that the mechanical properties of the wet crosslinked CS-g-PVA/PVA membrane were comparable to those of other membranes made it a promising material to be used as an electrolyte membrane in a direct methanol fuel cell.

Electrospun chitosan nanofibre membranes for antimicrobial application: role of electrospinning processing parameters

CSIR Research Space (South Africa)

Jacobs, V

2010-01-01

Full Text Available for biomedical applications such as wound dressing. In this paper, the authors report investigation on the effects of governing parameters on the formation of chitosan nanofibre membranes. These membranes were subjected to various cell cultures for antibacterial...

Chitosan-silica complex membranes from sulfonic acid functionalized silica nanoparticles for pervaporation dehydration of ethanol-water solutions.

Science.gov (United States)

Liu, Ying-Ling; Hsu, Chih-Yuan; Su, Yu-Huei; Lai, Juin-Yih

2005-01-01

Nanosized silica particles with sulfonic acid groups (ST-GPE-S) were utilized as a cross-linker for chitosan to form a chitosan-silica complex membranes, which were applied to pervaporation dehydration of ethanol-water solutions. ST-GPE-S was obtained from reacting nanoscale silica particles with glycidyl phenyl ether, and subsequent sulfonation onto the attached phenyl groups. The chemical structure of the functionalized silica was characterized with FTIR, (1)H NMR, and energy-dispersive X-ray. Homogeneous dispersion of the silica particles in chitosan was observed with electronic microscopies, and the membranes obtained were considered as nanocomposites. The silica nanoparticles in the membranes served as spacers for polymer chains to provide extra space for water permeation, so as to bring high permeation rates to the complex membranes. With addition of 5 parts per hundred of functionalized silica into chitosan, the resulting membrane exhibited a separation factor of 919 and permeation flux of 410 g/(m(2) h) in pervaporation dehydration of 90 wt % ethanol aqueous solution at 70 degrees C.

Effect of combination of chitosan coating and irradiation on physicochemical and functional properties of chicken egg during room-temperature storage

International Nuclear Information System (INIS)

Liu Xianxe; Jang, Aera; Kim, Dong Hun; Lee, Bong Duk; Lee, Mooha; Jo, Cheorun

2009-01-01

The effect of combination of chitosan coating and irradiation on quality and storage stability of shell egg was investigated. Salmonella typhimurium inoculated on eggshell was not detected by irradiation of 2.0 kGy at day 0 and/or chitosan coating (1%, pH 5.0) after 3 days of storage. One-day-old fresh chicken egg was chitosan coated and irradiated at 0, 0.5, 1.0, 1.5 and 2.0 kGy by gamma ray. The egg samples were stored at room temperature for 14 days and the effects of the combination treatment on internal physicochemical and functional properties were investigated. The Haugh unit of egg was decreased by irradiation even at 0.5 kGy. Irradiation increased the lipid oxidation in egg yolk at 2 kGy but the egg with chitosan coating reduced the level of lipid oxidation. Irradiation increased the foaming ability of egg white and decreased viscosity of egg yolk and white. Results suggested that combination of irradiation and chitosan coating can improve safety of shell egg but irradiation treatment may reduce the egg quality for direct consumption. However, an improved functional property for further processing and efficient separation of egg white and yolk can be expected for egg processing industry using irradiation.

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

Science.gov (United States)

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.

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)

Tolerance to chitosan by Trichoderma species is associated with low membrane fluidity.

Science.gov (United States)

Zavala-González, Ernesto A; Lopez-Moya, Federico; Aranda-Martinez, Almudena; Cruz-Valerio, Mayra; Lopez-Llorca, Luis Vicente; Ramírez-Lepe, Mario

2016-07-01

The effect of chitosan on growth of Trichoderma spp., a cosmopolitan genus widely exploited for their biocontrol properties was evaluated. Based on genotypic (ITS of 18S rDNA) characters, four isolates of Trichoderma were identified as T. pseudokoningii FLM16, T. citrinoviride FLM17, T. harzianum EZG47, and T. koningiopsis VSL185. Chitosan reduces radial growth of Trichoderma isolates in concentration-wise manner. T. koningiopsis VSL185 was the most chitosan tolerant isolate in all culture media amended with chitosan (0.5-2.0 mg ml(-1) ). Minimal Inhibitory Concentration (MIC) and Minimal Fungicidal Concentration (MFC) were determined showing that T. koningiopsis VSL185 displays higher chitosan tolerance with MIC value >2000 μg ml(-1) while for other Trichoderma isolates MIC values were around 10 μg ml(-1) . Finally, free fatty acid composition reveals that T. koningiopsis VSL185, chitosan tolerant isolate, displays lower linolenic acid (C18:3) content than chitosan sensitive Trichoderma isolates. Our findings suggest that low membrane fluidity is associated with chitosan tolerance in Trichoderma spp. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chitosan coated carbon fiber microelectrode for selective in vivo detection of neurotransmitters in live zebrafish embryos

International Nuclear Information System (INIS)

Ozel, Rifat Emrah; Wallace, Kenneth N.; Andreescu, Silvana

2011-01-01

Graphical abstract: Chitosan coated fiber electrodes are sensitive to serotonin detection while rejecting physiological levels of ascorbic acid interferences. - Abstract: We report the development of a chitosan modified carbon fiber microelectrode for in vivo detection of serotonin. We find that chitosan has the ability to reject physiological levels of ascorbic acid interferences and facilitate selective and sensitive detection of in vivo levels of serotonin, a common catecholamine neurotransmitter. Presence of chitosan on the microelectrode surface was investigated using scanning electron microscopy (SEM) and cyclic voltammetry (CV). The electrode was characterized using differential pulse voltammetry (DPV). A detection limit of 1.6 nM serotonin with a sensitivity of 5.12 nA/μM, a linear range from 2 to 100 nM and a reproducibility of 6.5% for n = 6 electrodes were obtained. Chitosan modified microelectrodes selectively measure serotonin in presence of physiological levels of ascorbic acid. In vivo measurements were performed to measure concentration of serotonin in the live embryonic zebrafish intestine. The sensor quantifies in vivo intestinal levels of serotonin while successfully rejecting ascorbic acid interferences. We demonstrate that chitosan can be used as an effective coating to reject ascorbic acid interferences at carbon fiber microelectrodes, as an alternative to Nafion, and that chitosan modified microelectrodes are reliable tools for in vivo monitoring of changes in neurotransmitter levels.

Chitosan coated carbon fiber microelectrode for selective in vivo detection of neurotransmitters in live zebrafish embryos

Energy Technology Data Exchange (ETDEWEB)

Ozel, Rifat Emrah [Department of Chemistry and Biomolecular Science, 8 Clarkson Ave, Potsdam, NY 136995810 (United States); Wallace, Kenneth N. [Department of Biology, Clarkson University, Potsdam, NY 136995810 (United States); Andreescu, Silvana, E-mail: eandrees@clarkson.edu [Department of Chemistry and Biomolecular Science, 8 Clarkson Ave, Potsdam, NY 136995810 (United States)

2011-06-10

Graphical abstract: Chitosan coated fiber electrodes are sensitive to serotonin detection while rejecting physiological levels of ascorbic acid interferences. - Abstract: We report the development of a chitosan modified carbon fiber microelectrode for in vivo detection of serotonin. We find that chitosan has the ability to reject physiological levels of ascorbic acid interferences and facilitate selective and sensitive detection of in vivo levels of serotonin, a common catecholamine neurotransmitter. Presence of chitosan on the microelectrode surface was investigated using scanning electron microscopy (SEM) and cyclic voltammetry (CV). The electrode was characterized using differential pulse voltammetry (DPV). A detection limit of 1.6 nM serotonin with a sensitivity of 5.12 nA/{mu}M, a linear range from 2 to 100 nM and a reproducibility of 6.5% for n = 6 electrodes were obtained. Chitosan modified microelectrodes selectively measure serotonin in presence of physiological levels of ascorbic acid. In vivo measurements were performed to measure concentration of serotonin in the live embryonic zebrafish intestine. The sensor quantifies in vivo intestinal levels of serotonin while successfully rejecting ascorbic acid interferences. We demonstrate that chitosan can be used as an effective coating to reject ascorbic acid interferences at carbon fiber microelectrodes, as an alternative to Nafion, and that chitosan modified microelectrodes are reliable tools for in vivo monitoring of changes in neurotransmitter levels.

Effect of the addition CNTs on performance of CaP/chitosan/coating deposited on magnesium alloy by electrophoretic deposition.

Science.gov (United States)

Zhang, Jie; Wen, Zhaohui; Zhao, Meng; Li, Guozhong; Dai, Changsong

2016-01-01

CaP/chitosan/carbon nanotubes (CNTs) coating on AZ91D magnesium alloy was prepared via electrophoretic deposition (EPD) followed by conversion in a phosphate buffer solution (PBS). The bonding between the layer and the substrate was studied by an automatic scratch instrument. The phase compositions and microstructures of the composite coatings were determined by using X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), Raman spectroscopy and scanning electron microscope (SEM). The element concentration and gentamicin concentration were respectively determined by inductively coupled plasma optical emission spectrometer (ICP-OES) test and ultraviolet spectrophotometer (UV). The cell counting kit (CCK) assay was used to evaluate the cytotoxicity of samples to SaOS-2 cells. The results showed that a few CNTs with their original tubular morphology could be found in the CaP/chitosan coating and they were beneficial for the crystal growth of phosphate and improvement of the coating bonding when the addition amount of CNTs in 500 ml of electrophoretic solution was from 0.05 g to 0.125 g. The loading amount of gentamicin increased and the releasing speed of gentamicin decreased after CNTs was added into the CaP/chitosan coating for immersion loading and EPD loading. The cell viability of Mg based CaP/chitosan/CNTs was higher than that of Mg based CaP/chitosan from 16 days to 90 days. Copyright © 2015 Elsevier B.V. All rights reserved.

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)

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)

Novel asymmetric chitosan/PVP/nanocellulose wound dressing: In vitro and in vivo evaluation.

Science.gov (United States)

Poonguzhali, R; Khaleel Basha, S; Sugantha Kumari, V

2018-06-01

The present study was to develop a novel chitosan based symmetric and asymmetric bionanocomposite for potential wound dressing application. Chitosan (C)/Poly (vinyl pyrrolidone) (P)/nanocellulose (NC) membrane were fabricated by salt leaching method with the addition of 3% and 5% wt of nanocellulose. To obtain asymmetric material one side of the membrane was coated by stearic acid (S) which could form hydrophobic surface and another side acts as a hydrophilic surface. Nanocellulose of size 2-10nm was synthesized and characterized by TEM analysis. SEM showed the hydrophilic surface of asymmetric bionanocomposite consists of porous structure and hydrophobic surface is smooth and homogeneous. The results revealed that the Chitosan/PVP/Nanocellulose 3%-Stearic acid (CPNC3%-S) had a moderate swelling ratio, porosity, barrier and mechanical properties. Incorporation of nanocellulose into chitosan/PVP matrix could enhance the antibacterial activity. The hydrophobic surface of the CPNC3%-S bionanocomposite shows water repellent and antiadhesion properties towards E. coli bacteria and also the hydrophilic surface exhibit excellent antibacterial property and cytotoxicity towards bacterial pathogens. In vivo wound healing test shows better re-epithelialization and wound contraction compared with control and Chitosan/PVP-stearic acid (CP-S) bionanocomposite. Asymmetric bionanocomposite Chitosan/PVP/Nanocellulose coated with 3%-Stearic acid (CPNC3%-S) exhibited very good invitro cytocompatibility and enabled a faster wound healing than symmetric dressing, hence showing great potential to be applied as wound dressings. Copyright © 2018 Elsevier B.V. All rights reserved.

Blend membrane of succinic acid-crosslinked chitosan grafted with heparin/PVA-PEG (polyvinyl alcohol-polyethylene glycol) and its characterization

Science.gov (United States)

Sangkota, V. D. A.; Lusiana, R. A.; Astuti, Y.

2018-04-01

Crosslinking and grafting reactions are required to modify the functional groups on chitosan to increase the number of its active groups. In this study, crosslinking reaction of succinic acid and grafting reaction of heparin on chitosan were conducted to produce a membrane as a candidate of a hemodialysis membrane. The mole ratio between chitosan and succinate acids was varied to obtain the best composition of modified materials. By blending all the material composition with PVA-PEG, the blend was transformed into a membrane. The resulted membrane was then characterized by various test methods such as tests of thickness, weight, water uptake, pH resistance, tensile strength and membrane hydrophilicity. The results showed that the best composition of the membrane reached in the addition of 0.011 gram of succinic acid proved by its highest mechanical strength compared to the other membranes.

Microwave-induced biomimetic approach for hydroxyapatite coatings of chitosan scaffolds.

Science.gov (United States)

Kaynak Bayrak, Gökçe; Demirtaş, T Tolga; Gümüşderelioğlu, Menemşe

2017-02-10

Simulated body fluid (SBF) can form calcium phosphates on osteoinductive materials, so it is widely used for coating of bone scaffolds to mimic natural extracellular matrix (ECM). However, difficulties of bulk coating in 3D scaffolds and the necessity of long process times are the common problems for coating with SBF. In the present study, a microwave-assisted process was developed for rapid and internal coating of chitosan scaffolds. The scaffolds were fabricated as superporous hydrogel (SPH) by combining microwave irradiation and gas foaming methods. Then, they were immersed into 10x  SBF-like solution and homogenous bone-like hydroxyapatite (HA) coating was achieved by microwave treatment at 600W without the need of any nucleating agent. Cell culture studies with MC3T3-E1 preosteoblasts showed that microwave-assisted biomimetic HA coating process could be evaluated as an efficient and rapid method to obtain composite scaffolds for bone tissue engineering. Copyright © 2016 Elsevier Ltd. All rights reserved.

Anastomotic stoma coated with chitosan film as a betamethasone dipropionate carrier for peripheral nerve regeneration

Directory of Open Access Journals (Sweden)

Ping Yao

2018-01-01

Full Text Available Scar hyperplasia at the suture site is an important reason for hindering the repair effect of peripheral nerve injury anastomosis. To address this issue, two repair methods are often used. Biological agents are used to block nerve sutures and the surrounding tissue to achieve physical anti-adhesion effects. Another agent is glucocorticosteroid, which can prevent scar growth by inhibiting inflammation. However, the overall effect of promoting regeneration of the injured nerve is not satisfactory. In this regard, we envision that these two methods can be combined and lead to shared understanding for achieving improved nerve repair. In this study, the right tibial nerve was transected 1 cm above the knee to establish a rat tibial nerve injury model. The incision was directly sutured after nerve transection. The anastomotic stoma was coated with 0.5 × 0.5 cm2 chitosan sheets with betamethasone dipropionate. At 12 weeks after injury, compared with the control and poly (D, L-lactic acid groups, chitosan-betamethasone dipropionate film slowly degraded with the shape of the membrane still intact. Further, scar hyperplasia and the degree of adhesion at anastomotic stoma were obviously reduced, while the regenerated nerve fiber structure was complete and arranged in a good order in model rats. Electrophysiological study showed enhanced compound muscle action potential. Our results confirm that chitosan-betamethasone dipropionate film can effectively prevent local scar hyperplasia after tibial nerve repair and promote nerve regeneration.

Properties of gelatin-based films incorporated with chitosan-coated microparticles charged with rutin.

Science.gov (United States)

Dammak, Ilyes; Bittante, Ana Mônica Quinta Barbosa; Lourenço, Rodrigo Vinicius; do Amaral Sobral, Paulo José

2017-08-01

The aim of this study was development an active film based on gelatin incorporated with antioxidant, rutin carried into microparticles. The complexation between oppositely charged lecithin and chitosan was applied to prepare the chitosan-coated microparticles. The generated microparticles had an average size of 520±4nm and a span of 0.3 were formulated by a rotor-stator homogenize at the homogenization speed 10,000rpm. Composite films were prepared by incorporating chitosan-coated microparticles, at various concentrations (0.05, 0.1, 0.5, or 1% (based on the weight of the gelatin powder)) in the gelatin-based films. For the prepared films, the results showed that obtained physicochemical, water vapor barrier, and mechanical were compared with native gelatin film with a slight decrease for chitosan concentration higher than 0.5%. The microstructure studies done by scanning electron microscopes, revealed different micropores embedded with oil resulting from the incorporation of the microparticles into the gelatin matrix. Moreover, the calorimetric results were comparable to those of gelatin control film with T g value 45°C and increased crystallinity percentage with increasing incorporation of microparticles. This original concept of composite biodegradable films may thus be a good alternative to incorporate liposoluble active compounds to design an active packaging with good properties. Copyright © 2017 Elsevier B.V. All rights reserved.

Fabrication of novel chitosan/PAN/magnetic ZSM-5 zeolite coated sponges for absorption of oil from water surfaces.

Science.gov (United States)

Samadi, Saman; Yazd, Shabnam Sharif; Abdoli, Hossein; Jafari, Pooya; Aliabadi, Majid

2017-12-01

In the present study, the chitosan (bottom layer)/polyacrylonitrile (top layer, PAN) nanofibers were coated on the sponge surface. The synthesized magnetic Fe 3 O 4 - ZSM-5 nanozeolites have been loaded into the chitosan/PAN nanofibers to increase the performance of nanofibers toward absorption of lubricating oil, motor oil and pump oil from water surfaces. Scanning electron microscope (SEM), Transmission electron microscope (TEM) and X-ray diffraction (XRD) analysis were used to characterize the synthesized nanozeolites. The morphology and wettability of nanofibers were determined using SEM and water contact angle tests. The influence of Fe 3 O 4 - ZSM-5 nanozeolite content and chitosan/PAN/Fe 3 O 4 - ZSM-5 nanofiber thickness was evaluated on the potential of sponges for oils absorption. The maximum capacity of the chitosan/PAN/Fe 3 O 4 - ZSM-5 nanofibers coated sponges for absorption of motor oil, lubricating oil and pump oil was found to be 99.4, 95.3 and 88.1g/g, in Fe 3 O 4 - ZSM-5 2wt.% and nanofiber thickness of 12μm (chitosan layer of 2μm and PAN layer of 10μm). The reusability of nanofibrous sponges showed that the hydrophobic chitosan/PAN/Fe 3 O 4 - ZSM-5 nanofibers coated sponges can be easily reused in water-oil separation for many cycles. Copyright © 2017 Elsevier B.V. All rights reserved.

Flame Retardant Multilayered Coatings on Acrylic Fabrics Prepared by One-Step Deposition of Chitosan/Montmorillonite Complexes

Directory of Open Access Journals (Sweden)

Federico Carosio

2018-06-01

Full Text Available Multilayered coatings deposited using the layer-by-layer (LbL assembly technique have attracted great interest in recent years as a sustainable and efficient solution for conferring flame retardant properties to fabrics. The unique structure and interaction established upon the coating assembly are the key factors for successful flame retardant properties. In this study we aimed at the deposition of multilayered coatings comprising chitosan and montmorillonite with a LbL-like structure and interactions by the simple processing of compacted chitosan/montmorillonite complexes obtained by the direct mixing of an oppositely charged solution/suspension. Upon drying, the prepared complex yielded a continuous coating characterized by a brick-and-mortar multi-layered structure, in which oriented clay nanoplatelets were held together by a continuous chitosan matrix. When deposited on acrylic fabrics these coatings were able to suppress the melt-dripping phenomenon, and at 10 and 20% add-ons achieved self-extinguishing behavior within a few seconds after ignition. Cone calorimetry testing revealed an increase in time to ignition (up to +46% and considerable reductions of the rates at which heat is released (up to −62 and −49% for peak of heat release rate and total heat release, respectively. A reduction in the total smoke release (up to −49% was also observed.

Preparation of stable alginate microcapsules coated with chitosan or polyethyleneimine for extraction of heavy metal ions.

Science.gov (United States)

Outokesh, Mohammad; Mimura, Hitoshi; Niibori, Yuichi; Tanaka, Kouichi

2006-05-01

Stable alginate microcapsules in dried form containing bis(2,4,4-trimethylpentyl) monothiophosphinic acid (HA) were prepared by coating of fresh alginate microcapsules with chitosan or polyethyleneimine (PEI). The thickness of coatings was estimated by electron probe microanalysis (EPMA), along with electron microscopy (SEM), as well as comparison of uptake percentage of coated and uncoated hollow capsules. Characterization of microcapsules was carried out by Ag(+) uptake experiments, destructive chemical analyses and thermogravimetric methods (TG and DTA). Chemical stability tests in HNO(3) and NaNO(3) media indicated that the coating with 4-double layer chitosan or mono-layer PEI led to an appreciable enhancement of impermeability in the range of pH > 1 or [Na(+)] microcapsules nearly completely hold their extractant content. Stable extractive microcapsules have an appreciable potential for the selective removal of heavy metal ions.

Influence of nitrogen ion implantation on filtration of fluoride and cadmium using polysulfone/chitosan blend membranes

Energy Technology Data Exchange (ETDEWEB)

Wanichapichart, P., E-mail: pikul.v@psu.ac.th [Membrane Science and Technology Research Center, Department of Physics, Faculty of Science, Prince of Songkla University, Songkhla 90110 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Bootluck, W. [Membrane Science and Technology Research Center, Department of Physics, Faculty of Science, Prince of Songkla University, Songkhla 90110 (Thailand); Thopan, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D. [Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

2014-05-01

Composite membranes between polysulfone and biopolymer chitosan were produced with variations of the chitosan content and temperature during the phase inversion process. The lower chitosan content led to lower water permeability and smaller membrane cut off. When the temperature of the phase inversion process was reduced from 25 °C to 5 °C, membrane pores were further decreased from somewhat greater than 10 kDa to a value smaller than 2 kDa. After being implanted with N-ions of 50 keV to a fluence of 1 × 10{sup 15} ions/cm{sup 2}, the composite membranes showed an improvement in the rejection by about 15% for fluoride and 10% for cadmium. In addition, a slight increase in permeation flux was observed in the ion implanted membranes. Filtration tests using the N-ion implanted membranes showed that fluoride was rejected from 100 ppm NaF solution by 47% and the rejection was increased to 60% when 2.20 ppm underground water was filtered. In the case of cadmium, the rejection was increased from 80% to 90% as an effect of the N-ion implantation.

Dynamic adsorption of mixtures of Rhodamine B, Pb (II), Cu (II) and Zn(II) ions on composites chitosan-silica-polyethylene glycol membrane

Science.gov (United States)

Mahatmanti, F. W.; Rengga, W. D. P.; Kusumastuti, E.; Nuryono

2018-04-01

The adsorption of a solution mixture of Rhodamine B, Pb (II), Cu (II) and Zn(II) was studied using dynamic methods employing chitosan-silica-polyethylene glycol (Ch/Si/P) composite membrane as an adsorptive membrane. The composite Ch/Si/P membrane was prepared by mixing a chitosan-based membrane with silica isolated from rice husk ash (ASP) and polyethylene glycol (PEG) as a plasticizer. The resultant composite membrane was a stronger and more flexible membrane than the original chitosan-based membrane as indicated by the maximum percentage of elongation (20.5 %) and minimum Young’s Modulus (80.5 MPa). The composite membrane also showed increased mechanical and hydrophilic properties compared to the chitosan membranes. The membrane was used as adsorption membrane for Pb (II), Cu (II), Cd (II) ions and Rhodamine B dyes in a dynamic system where the permeation and selectivity were determined. The permeation of the components was observed to be in the following order: Rhodamine B > Cd (II) > Pb (II) > Cu (II) whereas the selectivity was shown to decrease the order of Cu (II) > Pb (II) > Cd (II) > Rhodamine B.

Calcium phosphate/chitosan composite coating: Effect of different concentrations of Mg2+ in the m-SBF on its bioactivity

International Nuclear Information System (INIS)

Zhang, Jie; Dai, Changsong; Wei, Jie; Wen, Zhaohui; Zhang, Shujuan; Lin, Lemin

2013-01-01

The purpose of this study was to investigate the effect of different concentration of Mg 2+ in a modified simulated body fluid (m-SBF) on the bioactivity of calcium phosphate/chitosan composite coating. Calcium phosphate/chitosan composite coating was prepared on graphite substrate via electrophoretic deposition (EPD) followed by conversion in a phosphate buffer solution (PBS). The obtained samples were soaked in the m-SBF containing different concentration of Mg 2+ for different times. And then, the composite coatings were assessed using X-ray diffractometer (XRD), Fourier-transformed infrared spectroscopy (FTIR), Raman spectra, and scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS). The soaking solution was evaluated by inductively coupled plasma optical emission spectrometer (ICP-OES) test. The analytical results showed that hydroxyapatite (HA) and bone-like apatite (HCA) grew on the surface of calcium phosphate/chitosan composite coating after incubation in different m-SBF. With Mg 2+ concentration in m-SBF increased from 1× Mg to 10× Mg, HA in the composite coating first presented a dissolving process and then a precipitating one slowly, while HCA presented a growing trend, continuously. The increasing of Mg 2+ concentration in the m-SBF inhibited the total growing process of HA and HCA as a whole. The structure of the composite coating changed from spherical into irregular morphology with the concentration of Mg 2+ increasing from 1× Mg to 10× Mg. Over all, with the Mg 2+ concentration increasing, the bioactivity of calcium phosphate/chitosan composite coating tended to decrease.

Calcium phosphate/chitosan composite coating: Effect of different concentrations of Mg2+ in the m-SBF on its bioactivity

Science.gov (United States)

Zhang, Jie; Dai, Changsong; Wei, Jie; Wen, Zhaohui; Zhang, Shujuan; Lin, Lemin

2013-09-01

The purpose of this study was to investigate the effect of different concentration of Mg2+ in a modified simulated body fluid (m-SBF) on the bioactivity of calcium phosphate/chitosan composite coating. Calcium phosphate/chitosan composite coating was prepared on graphite substrate via electrophoretic deposition (EPD) followed by conversion in a phosphate buffer solution (PBS). The obtained samples were soaked in the m-SBF containing different concentration of Mg2+ for different times. And then, the composite coatings were assessed using X-ray diffractometer (XRD), Fourier-transformed infrared spectroscopy (FTIR), Raman spectra, and scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS). The soaking solution was evaluated by inductively coupled plasma optical emission spectrometer (ICP-OES) test. The analytical results showed that hydroxyapatite (HA) and bone-like apatite (HCA) grew on the surface of calcium phosphate/chitosan composite coating after incubation in different m-SBF. With Mg2+ concentration in m-SBF increased from 1× Mg to 10× Mg, HA in the composite coating first presented a dissolving process and then a precipitating one slowly, while HCA presented a growing trend, continuously. The increasing of Mg2+ concentration in the m-SBF inhibited the total growing process of HA and HCA as a whole. The structure of the composite coating changed from spherical into irregular morphology with the concentration of Mg2+ increasing from 1× Mg to 10× Mg. Over all, with the Mg2+ concentration increasing, the bioactivity of calcium phosphate/chitosan composite coating tended to decrease.

H3PO4 imbibed polyacrylamide-graft-chitosan frameworks for high-temperature proton exchange membranes

Science.gov (United States)

Yuan, Shuangshuang; Tang, Qunwei; He, Benlin; Chen, Haiyan; Li, Qinghua; Ma, Chunqing; Jin, Suyue; Liu, Zhichao

2014-03-01

Proton exchange membrane (PEM), transferring protons from anode to cathode, is a key component in a PEM fuel cell. In the current work, a new class of PEMs are synthesized benefiting from the imbibition behavior of three-dimensional (3D) polyacrylamide-graft-chitosan (PAAm-graft-chitosan) frameworks to H3PO4 aqueous solution. Interconnected 3D framework of PAAm-graft-chitosan provides tremendous space for holding proton-conducting H3PO4. The highest anhydrous proton conductivity of 0.13 S cm-1 at 165 °C is obtained. A fuel cell using a thick membrane as a PEM showed a peak power density of 405 mW cm-2 with O2 and H2 as the oxidant and fuel, respectively. Results indicate that the interconnected 3D framework provides superhighway for proton conduction. The valued merits on anhydrous proton conductivity, huge H3PO4 loading, and easy synthesis promise the new membranes to be good alternatives as high-temperature PEMs.

Chitosan Glutamate-Coated Niosomes: A Proposal for Nose-to-Brain Delivery

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Federica Rinaldi

2018-03-01

Full Text Available The aim of this in vitro study is to prepare and characterize drug free and pentamidine loaded chitosan glutamate coated niosomes for intranasal drug delivery to reach the brain through intranasal delivery. Mucoadhesive properties and stability testing in various environments were evaluated to examine the potential of these formulations to be effective drug delivery vehicles for intranasal delivery to the brain. Samples were prepared using thin film hydration method. Changes in size and ζ-potential of coated and uncoated niosomes with and without loading of pentamidine in various conditions were assessed by dynamic light scattering (DLS, while size and morphology were also studied by atomic force microscopy (AFM. Bilayer properties and mucoadhesive behavior were investigated by fluorescence studies and DLS analyses, respectively. Changes in vesicle size and ζ-potential values were shown after addition of chitosan glutamate to niosomes, and when in contact with mucin solution. In particular, interactions with mucin were observed in both drug free and pentamidine loaded niosomes regardless of the presence of the coating. The characteristics of the proposed systems, such as pentamidine entrapment and mucin interaction, show promising results to deliver pentamidine or other possible drugs to the brain via nasal administration.

Releasing growth factors from activated human platelets after chitosan stimulation: a possible bio-material for platelet-rich plasma preparation.

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Shen, E-Chin; Chou, Tz-Chong; Gau, Ching-Hwa; Tu, Hsiao-Pei; Chen, Yen-Teen; Fu, Earl

2006-10-01

Thrombin is commonly used for activating the platelets and releasing the growth factors on the application of platelet-rich plasma (PRP). We have previously reported that chitosan can enhance rabbit platelet aggregation. In this study, the effects of chitosan on the subsequent growth factors release after human platelets activation were examined to evaluate the possibility of chitosan being used as a substitute for thrombin during PRP preparation. Human platelet activation was determined by aggregation, adhesion and alpha-granule membrane glycoprotein expression. Platelet aggregation was measured by the turbidimetric method, the adhesion was directly examined on chitosan-coated glass plates under light microscope and scanning electron microscope (SEM), and the alpha-granule membrane glycoprotein was detected by fluorescent isothiocyanate (FITC)-conjugated anti-CD61 antibody through flow cytometry. The subsequent epidermal growth factor (EGF), platelet-derived growth factor (PDGF)-AB and transforming growth factor (TGF)-beta1 release from platelets were assayed by ELISA after mixing with chitosan. The enhancing effects on the platelet adhesion and the aggregation from chitosan were observed. Under both microscopes, the adhesive platelets on the chitosan-coated plates were not only greater in number but also earlier in activation than those on the control plates. With flow cytometry, increased glycoprotein IIIa expression in platelets was detected after chitosan treatment. Greater concentrations of growth factors were measured from PRP after chitosan treatment than after the solvent treatment. Because of the observations of growth factors releasing from activated human platelets after chitosan stimulation, we suggest that chitosan may be an appropriate substitute for thrombin in PRP preparation.

In vitro evaluation of electrospun chitosan mats crosslinked with genipin as guided tissue regeneration barrier membranes

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Norowski, Peter Andrew, Jr.

Guided tissue regeneration (GTR) is a surgical technique commonly used to exclude bacteria and soft tissues from bone graft sites in oral/maxillofacial bone graft sites by using a barrier membrane to maintain the graft contour and space. Current clinical barrier membrane materials based on expanded polytetrafluoroethylene (ePTFE) and bovine type 1 collagen are non-ideal and experience a number of disadvantages including membrane exposure, bacterial colonization/biofilm formation and premature degradation, all of which result in increased surgical intervention and poor bone regeneration. These materials do not actively participate in tissue regeneration, however bioactive materials, such as chitosan, may provide advantages such as the ability to stimulate wound healing and de novo bone formation. Our hypothesis is that electrospun chitosan GTR membranes will support cell attachment and growth but prevent cell infiltration/penetration of membrane, demonstrate in vitro degradation predictive of 4--6 month in vivo functionality, and will deliver antibiotics locally to prevent/inhibit periopathogenic complications. To test this hypothesis a series of chitosan membranes were electrospun, in the presence or absence of genipin, a natural crosslinking agent, at concentrations of 5 and 10 mM. These membranes were characterized by scanning electron microscopy, tensile testing, suture pullout testing, Fourier transform infrared spectroscopy, X-ray diffraction, and gel permeation chromatography, and in vitro biodegradation for diameter/morphology of fibers, membrane strengths, degree of crosslinking, crystallinity, molecular weight, and degradation kinetics, respectively. Cytocompability of membranes was evaluated in osteoblastic, fibroblastic and monocyte cultures. The activity of minocycline loaded and released from the membranes was determined in zone of inhibition tests using P. gingivalis microbe. The results demonstrated that genipin crosslinking extended the in vitro

Pervaporative dehydration characteristics of an ethanol/water azeotrope through various chitosan membranes.

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Uragami, Tadashi; Saito, Tomoyuki; Miyata, Takashi

2015-04-20

The permeation and separation characteristics of an ethanol/water azeotrope through chitosan membranes of different molecular weights and degrees of deacetylation during pervaporation were investigated. The normalized permeation rate decreased with increasing molecular weight up to 90 kDa, but at over 90 kDa, the rate increased. On the other hand, the water/ethanol selectivity increased with increasing molecular weight up to 90 kDa but decreased at over 90 kDa. With increasing degree of deacetylation, the water/ethanol permselectivity increased significantly, but the normalized permeation rate decreased. The characteristics of chitosan membranes are discussed based on their chemical and physical structures such as the contact angle, density, degree of swelling, and glass transition temperature. Copyright © 2014 Elsevier Ltd. All rights reserved.

Characteristic of ascorbic acid in crosslinked chitosan edible film as drug delivery system membrane

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Kistriyani Lilis

2018-01-01

Full Text Available Chitosan is a polysaccharide compound in the form of a linear polysaccharide consisting of N-acetyl glucosamine (GlcNAc and D-glucosamine (GlcN monomer, which is a derivative of deacetylization of chitin polymer. Chitin is one of common type of polysaccharide on earth after the excess cellulose from inveterbrata skeletons. Chitosan has anti-microbial properties. Based on this properties, chitosan is potentially used to be an edible film as drug delivery system membrane. Edible film was made by dissolving chitosan in 100 mL acetic acid 1%, then the plasticizer and crosslinker was added while heated at 60° C. It was molded and dried in oven at 50°C for 48 hours. Drug loading in the edible film could be controlled by remodeling membrane characteristics in the presence of crosslinker additions. The purpose of this study was to estimate the mass transfer coefficient (kCa of drug loading in various concentrations of ascorbic acid in the edible film. The characteristics of ascorbic acid in chitosan edible film could be seen from the number of drugs that could be loaded through the uv-vis spectrophotometric analysis. The higher concentration of ascorbic acid was added, the drug would be loaded more into edible film.

A healing method of tympanic membrane perforations using three-dimensional porous chitosan scaffolds.

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Kim, Jangho; Kim, Seung Won; Choi, Seong Jun; Lim, Ki Taek; Lee, Jong Bin; Seonwoo, Hoon; Choung, Pill-Hoon; Park, Keehyun; Cho, Chong-Su; Choung, Yun-Hoon; Chung, Jong Hoon

2011-11-01

Both surgical tympanoplasty and paper patch grafts are frequently procedured to heal tympanic membrane (TM) perforation or chronic otitis media, despite their many disadvantages. In this study, we report a new healing method of TM perforation by using three-dimensional (3D) porous chitosan scaffolds (3D chitosan scaffolds) as an alternative method to surgical treatment or paper patch graft. Various 3D chitosan scaffolds were prepared; and the structural characteristics, mechanical property, in vitro biocompatibility, and healing effects of the 3D chitosan scaffolds as an artificial TM in in vivo animal studies were investigated. A 3D chitosan scaffold of 5 wt.% chitosan concentration showed good proliferation of TM cells in an in vitro study, as well as suitable structural characteristics and mechanical property, as compared with either 1% or 3% chitosan. In in vivo animal studies, 3D chitosan scaffold were able to migrate through the pores and surfaces of TM cells, thus leading to more effective TM regeneration than paper patch technique. Histological observations demonstrated that the regenerated TM with the 3D chitosan scaffold consisted of three (epidermal, connective tissue, and mucosal) layers and were thicker than normal TMs. The 3D chitosan scaffold technique may be an optimal healing method used in lieu of surgical tympanoplasty in certain cases to heal perforated TMs.

Study on the bonding strength between calcium phosphate/chitosan composite coatings and a Mg alloy substrate

Energy Technology Data Exchange (ETDEWEB)

Zhang Jie [School of Chemistry Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); Pharmacy College, Jiamusi University, Jiamusi 154007 (China); Dai Changsong, E-mail: changsd@hit.edu.cn [School of Chemistry Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); Wei Jie [School of Chemistry Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); School of Chemistry and Bioengineering, Suzhou Science Technology University, Suzhou 215009 (China); Wen Zhaohui, E-mail: wenzhaohui1968@163.com [Department of Neuro intern, First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China)

2012-11-15

Highlights: Black-Right-Pointing-Pointer Calcium phosphate/chitosan composite coatings on the MAO-AZ91D alloy were prepared. Black-Right-Pointing-Pointer The bonding force between the coating and the magnesium alloy was optimized. Black-Right-Pointing-Pointer The composite coating slowed down the corrosion rate of magnesium alloy in m-SBF. - Abstract: In order to improve the bonding strength between calcium phosphate/chitosan composite coatings and a micro-arc oxidized (MAO)-AZ91D Mg alloy, different influencing parameters were investigated in the process of electrophoretic deposition (EPD) followed by conversion in a phosphate buffer solution (PBS). Surface morphology and phase constituents of the as-prepared materials were investigated by using X-ray diffractometer (XRD), Fourier-transformed infrared spectrophotometer (FTIR), Raman spectrometer, scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS), and a thermo gravimetric and differential thermal analyzer (TG-DTA). Scratch tests were carried out to study the bonding properties between the coatings and the substrates. In vitro immersion tests were conducted to determine the corrosion behaviors of samples with and without deposit layers through electrochemical experiments. In the EPD process, the acetic acid content in the electrophoresis suspension and the electrophoretic voltage played important roles in improving the bonding properties, while the contents of chitosan (CS) and nano-hydroxyapatite (nHA, Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}) in the suspension had less significant influences on the mechanical bonding strength. It was observed that the coatings showed the excellent bonding property when an electrophoretic voltage was in a range of 40-110 V with other reagent amounts as follows: acetic acid: 4.5 vol.%, CS {<=} 0.25 g, nHA {<=} 2.0 g in 200 ml of a CS-acetic acid aqueous solution and nHA {<=} 2.5 g in 300 ml of absolute ethanol. The morphology of the composite coating

Study on the bonding strength between calcium phosphate/chitosan composite coatings and a Mg alloy substrate

International Nuclear Information System (INIS)

Zhang Jie; Dai Changsong; Wei Jie; Wen Zhaohui

2012-01-01

Highlights: ► Calcium phosphate/chitosan composite coatings on the MAO-AZ91D alloy were prepared. ► The bonding force between the coating and the magnesium alloy was optimized. ► The composite coating slowed down the corrosion rate of magnesium alloy in m-SBF. - Abstract: In order to improve the bonding strength between calcium phosphate/chitosan composite coatings and a micro-arc oxidized (MAO)-AZ91D Mg alloy, different influencing parameters were investigated in the process of electrophoretic deposition (EPD) followed by conversion in a phosphate buffer solution (PBS). Surface morphology and phase constituents of the as-prepared materials were investigated by using X-ray diffractometer (XRD), Fourier-transformed infrared spectrophotometer (FTIR), Raman spectrometer, scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS), and a thermo gravimetric and differential thermal analyzer (TG–DTA). Scratch tests were carried out to study the bonding properties between the coatings and the substrates. In vitro immersion tests were conducted to determine the corrosion behaviors of samples with and without deposit layers through electrochemical experiments. In the EPD process, the acetic acid content in the electrophoresis suspension and the electrophoretic voltage played important roles in improving the bonding properties, while the contents of chitosan (CS) and nano-hydroxyapatite (nHA, Ca 10 (PO 4 ) 6 (OH) 2 ) in the suspension had less significant influences on the mechanical bonding strength. It was observed that the coatings showed the excellent bonding property when an electrophoretic voltage was in a range of 40–110 V with other reagent amounts as follows: acetic acid: 4.5 vol.%, CS ≤ 0.25 g, nHA ≤ 2.0 g in 200 ml of a CS–acetic acid aqueous solution and nHA ≤ 2.5 g in 300 ml of absolute ethanol. The morphology of the composite coating obtained under the above optimal condition had a flake-like crystal structure. The EPD in

Procion Green H-4G immobilized poly(hydroxyethylmethacrylate/chitosan) composite membranes for heavy metal removal

International Nuclear Information System (INIS)

Genc, Oe.; Soysal, L.; Bayramoglu, G.; Arica, M.Y.; Bektas, S.

2003-01-01

The effective removal of toxic heavy metals from environmental samples still remains a major topic of present research. Metal-chelating membranes are very promising materials as adsorbents when compared with conventional beads because they are not compressible, and they eliminate internal diffusion limitations. The purpose of this study was to evaluate the performance of a novel adsorbent, Procion Green H-4G immobilized poly(hydroxyethylmethacrylate (HEMA)/chitosan) composite membranes, for the removal of three toxic heavy metal ions, namely, Cd(II), Pb(II) and Hg(II) from aquatic systems. The Procion Green H-4G immobilized poly(hydroxyethylmethacrylate/chitosan) composite membranes were characterized by elemental analysis, scanning electron microscopy and Fourier transform infrared (FTIR) spectroscopy. The immobilized amount of the Procion Green H-4G was calculated as 0.018±0.003 μmol/cm 2 from the nitrogen and sulphur stoichiometry. The adsorption capacity of Procion Green H-4G immobilized poly(hydroxyethylmethacrylate/chitosan) composite membranes for selected heavy metal ions from aqueous media containing different amounts of these ions (30-400 mg/l) and at different pH values (2.0-6.0) was investigated. The amount of Cd(II), Pb(II) and Hg(II) adsorbed onto the membranes measured at equilibrium, increased with time during the first 45 min and then remained unchanged toward the equilibrium adsorption. The maximum amounts of heavy metal ions adsorbed were 43.60±1.74, 68.81±2.75 and 48.22±1.92 mg/g for Cd(II), Pb(II) and Hg(II), respectively. The heavy metal ion adsorption on the pHEMA/chitosan membranes (carrying no dye) were relatively low, 6.31±0.13 mg/g for Cd(II), 18.73±0.37 mg/g for Pb(II) and 18.82±0.38 mg/g for Hg(II). Competitive adsorption of the metal ions was also studied. When the metal ions competed with each other, the adsorbed amounts were 12.74±0.38 mg Cd(II)/g, 28.80±0.86 mg Pb(II)/g and 18.41±0.54 mg Hg(II)/g. Procion Green H-4G

Thermodynamics of the Cu(II) adsorption on thin vanillin-modified chitosan membranes

International Nuclear Information System (INIS)

Cestari, Antonio R.; Vieira, Eunice F.S.; Mattos, Charlene R.S.

2006-01-01

In this work, low-density vanillin-modified thin chitosan membranes were synthesized and characterized. The membranes were utilized as adsorbent for the removal of Cu(II) from aqueous solutions. The experimental data obtained in batch experiments at different temperatures were fitted to the Langmuir and Freundlich isotherms to obtain the characteristic parameters of each model. The adsorption equilibrium data fitted well with the Langmuir model (average R 2 > 0.99). Interactions thermodynamic parameters (Δ int H, Δ int G, and Δ int S), as well as the interaction thermal effects (Q int ) were determined from T = (298 to 333) K. The thermodynamic parameters, the Dubinin-Radushkevick equation and the comparative values of Δ int H for some Cu(II)-adsorbent interactions suggested that the adsorption of Cu(II) ions to vanillin-chitosan membranes show average results for both the diffusional (endothermic) and chemical bonding (exothermic) processes in relation to the temperature range studied

Effect of deacetylation on property of electrospun chitosan/PVA nanofibrous membrane and removal of methyl orange, Fe(III) and Cr(VI) ions.

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Habiba, Umma; Siddique, Tawsif A; Talebian, Sepehr; Lee, Jacky Jia Li; Salleh, Areisman; Ang, Bee Chin; Afifi, Amalina M

2017-12-01

In this study, effect of degree of deacetylation on property and adsorption capacity of chitosan/polyvinyl Alcohol electrospun membrane has been investigated. Resulting nanofibers were characterized by FESEM, FTIR, XRD, TGA, tensile testing, weight loss test and adsorption test. FESEM result shows, finer nanofiber was fabricated from 42h hydrolyzed chitosan and PVA blend solution. FTIR and XRD result showed a strong interaction between chitosan and polyvinyl alcohol. Higher tensile strength was observed for the nanofiber having 42h hydrolyzed chitosan. Blend solution of chitosan/PVA having low DD chitosan had higher viscosity. The nanofibrous membrane was stable in distilled water, acidic and basic medium. The isotherm study shows that the adsorption capacity (q m ) of nanofiber containing higher DD chitosan was higher for Cr(VI). In contrary, the membrane containing chitosan with lower DD showed the higher adsorption capacity for Fe(III) and methyl orange. Moreover, the effect of DD on removal percentage of adsorbate was dependent on the initial concentration of the adsorbate. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fabrication of Electrospun Polyamide-6/Chitosan Nanofibrous Membrane toward Anionic Dyes Removal

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Mozhdeh Ghani

2014-01-01

Full Text Available Nanofibrous filter media of polyamide-6/chitosan were fabricated by electrospinning onto a satin fabric substrate and characterized by scanning electron microscopy (SEM, Fourier transform infrared spectroscopy (FTIR, and water contact angle (WCA. Anionic dye removal capability of the filter was investigated for Solophenyl Red 3BL and Polar Yellow GN, respectively, as acidic and direct dyes were investigated with respect to solution parameters (pH and initial dye concentration and membrane parameters (electrospinning time and chitosan ratio through filtration system. Experiments were designed using response surface methodology (RSM based on five-level central composite design (CCD with four parameters to maximize removal efficiency of the filter media. Moreover, the effect of parameters and their likely interactions on dye removal were investigated by mathematically developed models. The optimum values for solution pH, initial dye concentration, electrospinning time, and chitosan ratio were predicted to be 5, 50 mg/L, 4 hr, 30% and 5, 100 mg/L, 4 hr, 10%, respectively, for achieving 96% and 95% removal of Solophenyl Red 3BL and Polar Yellow GN. Evaluation of the estimation capability of applied models revealed that the models have a good agreement with experimental values. This study demonstrated that polyamide-6/chitosan nanofibrous membrane has an enormous applicable potential in dye removal from aqueous solutions.

Calcium phosphate/chitosan composite coating: Effect of different concentrations of Mg{sup 2+} in the m-SBF on its bioactivity

Energy Technology Data Exchange (ETDEWEB)

Zhang, Jie [School of Chemistry Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); Pharmacy College, Jiamusi University, Jiamusi 154007 (China); Dai, Changsong, E-mail: changsd@hit.edu.cn [School of Chemistry Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); Wei, Jie [School of Chemistry Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); School of Chemistry and Bioengineering, Suzhou Science Technology University, Suzhou 215009 (China); Wen, Zhaohui, E-mail: wenzhaohui1968@163.com [Department of neuro intern, First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China); Zhang, Shujuan; Lin, Lemin [Department of neuro intern, First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China)

2013-09-01

The purpose of this study was to investigate the effect of different concentration of Mg{sup 2+} in a modified simulated body fluid (m-SBF) on the bioactivity of calcium phosphate/chitosan composite coating. Calcium phosphate/chitosan composite coating was prepared on graphite substrate via electrophoretic deposition (EPD) followed by conversion in a phosphate buffer solution (PBS). The obtained samples were soaked in the m-SBF containing different concentration of Mg{sup 2+} for different times. And then, the composite coatings were assessed using X-ray diffractometer (XRD), Fourier-transformed infrared spectroscopy (FTIR), Raman spectra, and scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS). The soaking solution was evaluated by inductively coupled plasma optical emission spectrometer (ICP-OES) test. The analytical results showed that hydroxyapatite (HA) and bone-like apatite (HCA) grew on the surface of calcium phosphate/chitosan composite coating after incubation in different m-SBF. With Mg{sup 2+} concentration in m-SBF increased from 1× Mg to 10× Mg, HA in the composite coating first presented a dissolving process and then a precipitating one slowly, while HCA presented a growing trend, continuously. The increasing of Mg{sup 2+} concentration in the m-SBF inhibited the total growing process of HA and HCA as a whole. The structure of the composite coating changed from spherical into irregular morphology with the concentration of Mg{sup 2+} increasing from 1× Mg to 10× Mg. Over all, with the Mg{sup 2+} concentration increasing, the bioactivity of calcium phosphate/chitosan composite coating tended to decrease.

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-02-01

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

ANTIMICROBIAL PROPERTIES OF HYDROXYAPATITE COATINGS CONTAINING OF CHITOSAN AND SILVER ON TITANIUM SUBSTRATES IN RELATION TO MICROORGANISMS E.COLI ATCC 25922

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Sukhodub LB

2013-03-01

Full Text Available In this work it was studied the antibacterial properties of coatings based on HA, with Chitosan and silver ions additions, produced by substrates termodeposition method from aqueous solutions with varying concentrations of Chitosan (0.025 and 0.1 g/l and silver (1 mg/l as the antimicrobial components as well as three-part cover, consisting of a film of Chitosan, HA and silver. Study on antibacterial properties of composite coatings on the pathogen E.coli ATCC 25922 was held by Spectrophotometric measurement and analysis of optical density of suspensions, containing samples. 3 series of measurements data were averaged. The results showed that the concentration of antimicrobial components have indicated a bacteriostatic effect of coatings on the culture of E. coli AS ATCC 25922 in physiological solution at a temperature of 37 °C. The most effective was the three-part cover consisting of a film of chitosan, HA and silver.

Structural coloration of chitosan coated cellulose fabrics by electrostatic self-assembled poly (styrene-methyl methacrylate-acrylic acid) photonic crystals.

Science.gov (United States)

Yavuz, Gönül; Zille, Andrea; Seventekin, Necdet; Souto, Antonio P

2018-08-01

The structural coloration of a chitosan-coated woven cotton fabric obtained by glutaraldehyde-stabilized deposition of electrostatic self-assembled monodisperse and spherically uniform (250 nm) poly (styrene-methyl methacrylate-acrylic acid) photonic crystal nanospheres (P(St-MMA-AA)) was investigated. Bright iridescent coatings displaying different colors in function of the viewing angle were obtained. The SEM, diffuse reflectance spectroscopy, TGA, DSC and FTIR analyses confirm the presence of structural color and the glutaraldehyde and chitosan ability to provide durable chemical bonding between cotton fabric and photonic crystal (PCs) coating with the highest degradation temperature and the lowest enthalpy. The coatings are characterized by a mixture of face-centered cubic and hexagonal close-packed arrays alternating random packing regions. For the first time a cost-efficient structural coloration with high washing and light fastness using self-assembled P(St-MMA-AA) photonic crystals was successfully developed onto woven cotton fabric using chitosan and/or glutaraldehyde as stabilizing agent opening new strategies for the development of dye-free coloration of textiles. Copyright © 2018 Elsevier Ltd. All rights reserved.

Long-term liver-specific functions of hepatocytes in electrospun chitosan nanofiber scaffolds coated with fibronectin.

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Rajendran, Divya; Hussain, Ali; Yip, Derek; Parekh, Amit; Shrirao, Anil; Cho, Cheul H

2017-08-01

In this study, a new 3D liver model was developed using biomimetic nanofiber scaffolds and co-culture system consisting of hepatocytes and fibroblasts for the maintenance of long-term liver functions. The chitosan nanofiber scaffolds were fabricated by the electrospinning technique. To enhance cellular adhesion and spreading, the surfaces of the chitosan scaffolds were coated with fibronectin (FN) by adsorption and evaluated for various cell types. Cellular phenotype, protein expression, and liver-specific functions were extensively characterized by immunofluorescent and histochemical stainings, albumin enzyme-linked immunosorbent assay and Cytochrome p450 detoxification assays, and scanning electron microscopy. The electrospun chitosan scaffolds exhibited a highly porous and randomly oriented nanofibrous structure. The FN coating on the surface of the chitosan nanofibers significantly enhanced cell attachment and spreading, as expected, as surface modification with this cell adhesion molecule on the chitosan surface is important for focal adhesion formation and integrin binding. Comparison of hepatocyte mono-cultures and co-cultures in 3D culture systems indicated that the hepatocytes in co-cultures formed colonies and maintained their morphologies and functions for prolonged periods of time. The 3D liver tissue model developed in this study will provide useful tools toward the development of engineered liver tissues for drug screening and tissue engineering applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2119-2128, 2017. © 2017 Wiley Periodicals, Inc.

Electrophoretic deposition of graphene oxide reinforced chitosan-hydroxyapatite nanocomposite coatings on Ti substrate.

Science.gov (United States)

Shi, Y Y; Li, M; Liu, Q; Jia, Z J; Xu, X C; Cheng, Y; Zheng, Y F

2016-03-01

Electrophoretic deposition (EPD) is a facile and feasible technique to prepare functional nanocomposite coatings for application in orthopedic-related implants. In this work, a ternary graphene oxide-chitosan-hydroxyapatite (GO-CS-HA) composite coating on Ti substrate was successfully fabricated by EPD. Coating microstructure and morphologies were investigated by scanning electron microscopy, contact angle test, Raman spectroscopy, Fourier transform infrared spectroscopy and thermogravimetric analysis. It was found GO-CS surface were uniformly decorated by HA nanoparticles. The potentiodynamic polarization test in simulated body fluid indicated that the GO-CS-HA coatings could provide effective protection of Ti substrate from corrosion. This ternary composite coating also exhibited good biocompatibility during incubation with MG63 cells. In addition, the nanocomposite coatings could decrease the attachment of Staphylococcus aureus.

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

International Nuclear Information System (INIS)

Catalano, E; Di Benedetto, A

2017-01-01

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

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

Science.gov (United States)

Catalano, E.; Di Benedetto, A.

2017-05-01

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

Production of chitosan-based non-woven membranes using the electrospinning process

Science.gov (United States)

Pakravan Lonbani, Mehdi

Chitosan is a modified natural polymer mainly produced from chitin, one of the most abundant organic materials in the world. Highly porous chitosan mats present the specific physicochemical properties of the base material and also benefit from the physical characteristics of nanoporous membranes. Electrospinning is a novel technique developed long time ago and revisited recently that can generate polymeric fibers with nanometric size. The ultimate purpose of this work is to fabricate microporous non-woven chitosan membranes for wound healing dressings and heavy metal ion removal from drinking water. In this dissertation, two approaches have been utilized to prepare chitosan-based nanofibers; blending and co-axial electrospinning of chitosan solution with a readily electrospinnable solution, i.e. an aqueous solution of polyethylene oxide (PEO). Consequently, understanding the phase behavior and miscibility of aqueous acidic solutions of chitosan and PEO and their blends is of crucial importance, as any phase separation occurring during the electrospinning process greatly changes the morphology and physico-mechanical properties of the final products. First we employed the rheological approach on a well-known aqueous PEO solution to develop the experimental protocol. By comparing these critical points with that obtained from other experimental techniques, we showed that rheological measurements can sensitively detect early stages of phase separation. Subsequently the method was applied to 50 wt% aqueous acetic acid solutions of PEO, chitosan and their blends at different ratios. These solutions showed a lower critical solution temperature (LCST) phase diagram that is attributed to the existence of hydrogen bonds between active groups on chitosan and PEO backbone and the solvent. Critical decomposition temperatures for binodal and spinodal points were estimated from isochronal temperature sweep experiments. The obtained binodal temperatures confirmed that chitosan

Effects of Chitosan-Essential Oil Coatings on Safety and Quality of Fresh Blueberries

Science.gov (United States)

Chitosan coating plus different essential oils was developed and applied to fresh blueberries, in order to find environmentally friendly and healthy treatments to preserve fresh fruit quality and safety during postharvest storage. Studies were first performed in vitro where wild-type Escherichia col...

Curcumin drug delivery by vanillin-chitosan coated with calcium ferrite hybrid nanoparticles as carrier.

Science.gov (United States)

Kamaraj, Sriram; Palanisamy, Uma Maheswari; Kadhar Mohamed, Meera Sheriffa Begum; Gangasalam, Arthanareeswaran; Maria, Gover Antoniraj; Kandasamy, Ruckmani

2018-04-30

The aim of the present investigation is the development, optimization and characterization of curcumin-loaded hybrid nanoparticles of vanillin-chitosan coated with super paramagnetic calcium ferrite. The functionally modified vanillin-chitosan was prepared by the Schiff base reaction to enhance the hydrophobic drug encapsulation efficiency. Calcium ferrite (CFNP) nano particles were added to the vanillin modified chitosan to improve the biocompatibility. The vanillin-chitosan-CFNP, hybrid nanoparticle carrier was obtained by ionic gelation method. Characterizations of the hybrid materials were performed by XRD, FTIR, 1 H NMR, TGA, AFM and SEM techniques to ensure the modifications on the chitosan material. Taguchi method was applied to optimize the drug (curcumin) encapsulation efficiency by varying the drug to chitosan-vanillin, CFNP to chitosan-vanillin and TPP (sodium tripolyphospate) to chitosan-vanillin ratios. The maximum encapsulation efficiency was obtained as 98.3% under the conditions of 0.1, 0.75 and 1.0 for the drug to chitosan-vanillin, CFNP to chitosan-vanillin and TPP to chitosan-vanillin ratios, respectively. The curcumin release was performed at various pH, initial drug loading concentrations and magnetic fields. The drug release mechanism was predicted by fitting the experimental kinetic data with various drug release models. The drug release profiles showed the best fit with Higuchi model under the most of conditions. The drug release mechanism followed both non-Fickian diffusion and case II transport mechanism for chitosan, however the non-Fickian diffusion mechanism was followed for the vanillin modified chitosan. The biocompatibility of the hybrid material was tested using L929 fibroblast cells. The cytotoxicity test was performed against MCF-7 breast cancer cell line to check the anticancer property of the hybrid nano carrier with the curcumin drug. Copyright © 2018 Elsevier B.V. All rights reserved.

Development of cesium phosphotungstate salt and chitosan composite membrane for direct methanol fuel cells.

Science.gov (United States)

Xiao, Yanxin; Xiang, Yan; Xiu, Ruijie; Lu, Shanfu

2013-10-15

A novel composite membrane has been developed by doping cesium phosphotungstate salt (CsxH3-xPW12O40 (0≤x≤3), Csx-PTA) into chitosan (CTS/Csx-PTA) for application in direct methanol fuel cells (DMFCs). Uniform distribution of Csx-PTA nanoparticles has been achieved in the chitosan matrix. The proton conductivity of the composite membrane is significantly affected by the Csx-PTA content in the composite membrane as well as the Cs substitution in PTA. The highest proton conductivity for the CTS/Csx-PTA membranes was obtained with x=2 and Cs2-PTA content of 5 wt%. The value is 6×10(-3) S cm(-1) and 1.75×10(-2) S cm(-1) at 298 K and 353 K, respectively. The methanol permeability of CTS/Cs2-PTA membrane is about 5.6×10(-7), 90% lower than that of Nafion-212 membrane. The highest selectivity factor (φ) was obtained on CTS/Cs2-PTA-5 wt% composite membrane, 1.1×10(4)/Scm(-3)s. The present study indicates the promising potential of CTS/Csx-PTA composite membrane as alternative proton exchange membranes in direct methanol fuel cells. Copyright © 2013 Elsevier Ltd. All rights reserved.

Chitosan/polyanion surface modification of styrene–butadiene–styrene block copolymer membrane for wound dressing

Energy Technology Data Exchange (ETDEWEB)

Yang, Jen Ming, E-mail: jmyang@mail.cgu.edu.tw [Department of Chemical and Materials Engineering, Chang Gung University, Kwei-Shan, Tao-Yuan 333, Taiwan (China); Yang, Jhe-Hao [Department of Electronic Engineering, Chang Gung University, Kwei-Shan, Tao-Yuan 333, Taiwan (China); Huang, Huei Tsz [Department of Chemical and Materials Engineering, Chang Gung University, Kwei-Shan, Tao-Yuan 333, Taiwan (China)

2014-01-01

The surface of styrene–butadiene–styrene block copolymer (SBS) membrane is modified with tri-steps in this study. At first, two step modified SBS membrane (MSBS) was prepared with epoxidation and ring opening reaction with maleated ionomer. Then chitosan was used as the polycation electrolyte and sodium alginate, poly(γ-glutamic acid) (PGA) and poly(aspartic acid) (PAsp) were selected as polyanion electrolytes to deposit on the surfaces of MSBS membrane by the layer-by-layer self-assembly (LbL) deposition technique to get three [chitosan/polyanion] LbL modified SBS membranes, ([CS/Alg], [CS/PGA] and [CS/PAsp]). From the quantitative XPS analysis and water contact angle measurement, it is found that the order of wettability and the content of functional group percentages of COO{sup −} and -O=C-N- on the three [CS/polyanion] systems are [CS/Alg] > [CS/PGA] > [CS/PAsp]. Performances of water vapor transmission rates, fibronectin adsorption, antibacterial assessment and 3T3 fibroblast cell growth on [CS/Alg], [CS/PGA] and [CS/PAsp] membranes were also evaluated. With the evaluation of water vapor transmission rate, these [CS/Alg], [CS/PGA] and [CS/PAsp] membranes are sterile semipermeable with water evaporation at about 82 ± 8 g/day · m{sup 2}. It is found that the amount of fibronectin adsorption on the three [CS/polyanion] systems is significantly determined by the sum of the functional group of COO{sup −} and -O=C-N- on the surfaces of [CS/Alg], [CS/PGA] and [CS/PAsp] systems. The results are inverse with the sum of the functional group of COO{sup −} and -O=C-N- on the three [CS/polyanion]. From the cytotoxicity test and cell adhesion and proliferation assay of 3T3 fibroblasts on the three [CS/polyanion] systems, it revealed that the cells not only remained viable but they also proliferated on the surfaces of [CS/Alg], [CS/PGA] and [CS/PAsp]. The bactericidal activity was found on [CS/Alg], [CS/PGA] and [CS/PAsp]. The transport of bacterial through

Electrochemical behavior of polypyrrole/chitosan composite coating on Ti metal for biomedical applications.

Science.gov (United States)

Rikhari, Bhavana; Pugal Mani, S; Rajendran, N

2018-06-01

In the present work, the corrosion resistance performance and biocompatibility of polypyrrole/chitosan (PPy/CHI) composite coated Ti was studied. The deposition of composite coating was carried out by electropolymerization method. The deposited PPy/CHI composite coatings were different in morphology, structural, surface roughness and wettability compared PPy coated Ti. The presence of composite coating was confirmed by solid 13 C NMR. The PPy/CHI composite coating showed enhanced microhardness and adhesion strength compared to the PPy coating. The corrosion protection ability of PPy/CHI composite coatings at various applied potentials was analyzed by dynamic electrochemical impedance spectroscopy (DEIS), exhibited higher impedance in all the potentials compared to uncoated and PPy coated Ti. The lower corrosion current density obtained for PPy/CHI-2 composite coating from polarization studies revealed increased corrosion protection ability in SBF solution. The stability of composite coating was confirmed by immersion studies. PPy/CHI-2 composite coating immersed in SBF solution enhances hydroxyapatite (HAp) formation. Copyright © 2018 Elsevier Ltd. All rights reserved.

Preparation and characterization of antibacterial electrospun chitosan/poly (vinyl alcohol)/graphene oxide composite nanofibrous membrane

Science.gov (United States)

Yang, Shuai; Lei, Peng; Shan, Yujuan; Zhang, Dawei

2018-03-01

In this paper, chitosan (CS)/poly (vinyl alcohol) (PVA)/graphene oxide (GO) composite nanofibrous membranes were prepared via electrospinning. Such nanofibrous membranes have been characterized and investigated for their morphological, structural, thermal stability, hydrophilic and antibacterial properties. SEM images showed that the uniform and defect-free nanofibers were obtained and GO sheets, shaping spindle and spherical, were partially embedded into nanofibers. FTIR, XRD, DSC and TGA indicated the good compatibility between CS and PVA. There were strong intermolecular hydrogen bonds between the chitosan and PVA molecules. Contact angle measurement indicated that while increasing the content of GO, the distance between fibers increased and water drop showed wetting state on the surface of nanofibrous membranes. As a result, the contact angle decreased significantly. Meanwhile, good antibacterial activity of the prepared nanofibrous membranes were exhibited against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus.

One-step fabrication of biocompatible chitosan-coated ZnS and ZnS:Mn2+ quantum dots via a γ-radiation route

Science.gov (United States)

Chang, Shu-Quan; Kang, Bin; Dai, Yao-Dong; Zhang, Hong-Xu; Chen, Da

2011-11-01

Biocompatible chitosan-coated ZnS quantum dots [CS-ZnS QDs] and chitosan-coated ZnS:Mn2+ quantum dots [CS-ZnS:Mn2+ QDs] were successfully fabricated via a convenient one-step γ-radiation route. The as-obtained QDs were around 5 nm in diameter with excellent water-solubility. These QDs emitting strong visible blue or orange light under UV excitation were successfully used as labels for PANC-1 cells. The cell experiments revealed that CS-ZnS and CS-ZnS:Mn2+ QDs showed low cytotoxicity and good biocompatibility, which offered possibilities for further biomedical applications. Moreover, this convenient synthesis strategy could be extended to fabricate other nanoparticles coated with chitosan. PACS: 81.07.Ta; 78.67.Hc; 82.35.Np; 87.85.Rs.

Investigation of cell adhesion in chitosan membranes for peripheral nerve regeneration

Energy Technology Data Exchange (ETDEWEB)

Carvalho, Cristiana R.; López-Cebral, Rita; Silva-Correia, Joana; Silva, Joana M.; Mano, João F.; Silva, Tiago H. [3B' s Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark – Parque de Ciência e Tecnologia, 4805-017, Barco, Guimarães (Portugal); ICVS/3B' s - PT Government Associate Laboratory, Braga, Guimarães (Portugal); Freier, Thomas [MEDOVENT GmbH, Friedrich-Koenig-Str. 3, D-55129 Mainz (Germany); Reis, Rui L. [3B' s Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark – Parque de Ciência e Tecnologia, 4805-017, Barco, Guimarães (Portugal); ICVS/3B' s - PT Government Associate Laboratory, Braga, Guimarães (Portugal); Oliveira, Joaquim M., E-mail: miguel.oliveira@dep.uminho.pt [3B' s Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark – Parque de Ciência e Tecnologia, 4805-017, Barco, Guimarães (Portugal); ICVS/3B' s - PT Government Associate Laboratory, Braga, Guimarães (Portugal)

2017-02-01

Peripheral nerve injuries have produced major concerns in regenerative medicine for several years, as the recovery of normal nerve function continues to be a significant clinical challenge. Chitosan (CHT), because of its good biocompatibility, biodegradability and physicochemical properties, has been widely used as a biomaterial in tissue engineering scaffolding. In this study, CHT membranes were produced with three different Degrees of Acetylation (DA), envisioning its application in peripheral nerve regeneration. The three CHT membranes (DA I: 1%, DA II: 2%, DA III: 5%) were extensively characterized and were found to have a smooth and flat surface, with DA III membrane having slightly higher roughness and surface energy. All the membranes presented suitable mechanical properties and did not show any signs of calcification after SBF test. Biodegradability was similar for all samples, and adequate to physically support neurite outgrowth. The in vitro cell culture results indicate selective cell adhesion. The CHT membranes favoured Schwann cells invasion and proliferation, with a display of appropriate cytoskeletal morphology. At the same time they presented low fibroblast infiltration. This fact may be greatly beneficial for the prevention of fibrotic tissue formation, a common phenomenon impairing peripheral nerve regeneration. The great deal of results obtained during this work permitted to select the formulation with the greatest potential for further biological tests. - Highlights: • Three chitosan membranes were produced with very specific degrees of acetylation (DA I: 1%, DA II: 2%, DA III: 5%). • Physicochemical characterization of the membranes showed their suitability for peripheral nerve regeneration purposes. • In vitro cellular tests confirmed the potential of the membranes as peripheral nerve regeneration systems. • The results indicated that DA III membrane should be the one considered for further peripheral nerve regeneration studies.

Investigation of cell adhesion in chitosan membranes for peripheral nerve regeneration

International Nuclear Information System (INIS)

Carvalho, Cristiana R.; López-Cebral, Rita; Silva-Correia, Joana; Silva, Joana M.; Mano, João F.; Silva, Tiago H.; Freier, Thomas; Reis, Rui L.; Oliveira, Joaquim M.

2017-01-01

Peripheral nerve injuries have produced major concerns in regenerative medicine for several years, as the recovery of normal nerve function continues to be a significant clinical challenge. Chitosan (CHT), because of its good biocompatibility, biodegradability and physicochemical properties, has been widely used as a biomaterial in tissue engineering scaffolding. In this study, CHT membranes were produced with three different Degrees of Acetylation (DA), envisioning its application in peripheral nerve regeneration. The three CHT membranes (DA I: 1%, DA II: 2%, DA III: 5%) were extensively characterized and were found to have a smooth and flat surface, with DA III membrane having slightly higher roughness and surface energy. All the membranes presented suitable mechanical properties and did not show any signs of calcification after SBF test. Biodegradability was similar for all samples, and adequate to physically support neurite outgrowth. The in vitro cell culture results indicate selective cell adhesion. The CHT membranes favoured Schwann cells invasion and proliferation, with a display of appropriate cytoskeletal morphology. At the same time they presented low fibroblast infiltration. This fact may be greatly beneficial for the prevention of fibrotic tissue formation, a common phenomenon impairing peripheral nerve regeneration. The great deal of results obtained during this work permitted to select the formulation with the greatest potential for further biological tests. - Highlights: • Three chitosan membranes were produced with very specific degrees of acetylation (DA I: 1%, DA II: 2%, DA III: 5%). • Physicochemical characterization of the membranes showed their suitability for peripheral nerve regeneration purposes. • In vitro cellular tests confirmed the potential of the membranes as peripheral nerve regeneration systems. • The results indicated that DA III membrane should be the one considered for further peripheral nerve regeneration studies.

Vancomycin–chitosan composite deposited on post porous hydroxyapatite coated Ti6Al4V implant for drug controlled release

Energy Technology Data Exchange (ETDEWEB)

Yang, Chi-Chuan [Department of Materials Science and Engineering, National Chung Hsing, University 250, Kuo-Kuang Road, Taichung 40227, Taiwan (China); Lin, Chien-Chung [Department of Materials Science and Engineering, National Chung Hsing, University 250, Kuo-Kuang Road, Taichung 40227, Taiwan (China); Department of Orthopaedic Surgery, Taichung Armed Force General Hospital, 348, Sec. 2, Jhongshan Road, Taiping City, Taichung 411, Taiwan (China); Liao, Jiunn-Wang [Graduate Institute of Veterinary Pathobiology, National Chung Hsing, University 250, Kuo-Kuang Road, Taichung 40227, Taiwan (China); Yen, Shiow-Kang, E-mail: skyen@dragon.nchu.edu.tw [Department of Materials Science and Engineering, National Chung Hsing, University 250, Kuo-Kuang Road, Taichung 40227, Taiwan (China)

2013-05-01

Through the hydrogen bonds and the deprotonation, the vancomycin–chitosan composite has been originally deposited on Ti4Al4V by electrochemical technology. However, the rapid destruction of the hydrogen bonding between them by polar water molecules during immersion tests revealed 80% drug burst in a few hours. In this study, the post porous hydroxyapatite (HA) coated Ti4Al4V is prepared for the subsequent electrolytic deposition of vancomycin–chitosan composite to control the drug release. As expected, the initial burst is reduced to 55%, followed by a steady release about 20% from day 1 to day 5 and a slower release of the retained 25% after day 6, resulting in bacterial inhibition zone diameter of 30 mm which can last for more than a month in antibacterial tests, compared with the coated specimen without HA gradually loosing inhibition zone after 21 days. Besides, the cell culture indicates that the vancomycin–chitosan/HA composite coated has enhanced the proliferation, the differentiation and the mineralization of the osteoblast-like cell. In general, it is helpful for the osteointegration on permanent implants. Consistently, it effectively provides the prophylaxis and therapy of osteomyelitis according to the results of the rabbit infection animal model. - Highlights: ► The releasing curve of the vancomycin–chitosan/HA composite revealed three periods. ► The drug release sustained one month due to the effect of post porous HA coating. ► The composite coating could treat the osteomyelitis in the rabbit infection model.

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 .

Synthesis and characterization of diethylenetriaminepentaacetic acid-chitosan-coated cobalt ferrite core/shell nanostructures

Energy Technology Data Exchange (ETDEWEB)

Runhua, Qin [Department of Physics, North University of China, Taiyuan 030051 (China); National Special Superfine Powder Engineering Research Center, Nanjing University Science and Technology, Xiaolingwei 200, Nanjing 210094 (China); Li Fengsheng, E-mail: qinrunh@126.com [National Special Superfine Powder Engineering Research Center, Nanjing University Science and Technology, Xiaolingwei 200, Nanjing 210094 (China); Wei, Jiang; Mingyue, Chen [National Special Superfine Powder Engineering Research Center, Nanjing University Science and Technology, Xiaolingwei 200, Nanjing 210094 (China)

2010-08-01

Special diethylenetriaminepentaacetic acid (DTPA)-chitosan-coated cobalt ferrite core/shell nanoparticles have been synthesized via a novel zero-length emulsion crosslinking process and characterized via crosslinking degree, simultaneous thermogravimetric analysis and differential scanning calorimetry, X-ray diffractometry, Fourier transform infrared spectrometer, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and vibration sample magnetometry. The experimental results showed that the CoFe{sub 2}O{sub 4} nanoparticles were really encapsulated with a DTPA-chitosan hybrid layer and the nanocomposites were proved to be nearly superparamagnetic with saturation magnetization of 26.6 emu g{sup -1}.

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

Science.gov (United States)

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

2018-02-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-04-01

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

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

Drug release characteristics of quercetin-loaded TiO2 nanotubes coated with chitosan.

Science.gov (United States)

Mohan, L; Anandan, C; Rajendran, N

2016-12-01

TiO 2 nanotubes formed by anodic oxidation of Ti-6Al-7Nb were loaded with quercetin (TNTQ) and chitosan was coated on the top of the quercetin (TNTQC) to various thicknesses. Field emission scanning electron microscopy (FESEM), 3D and 2D analyses were used to characterize the samples. The drug release studies of TNTQ and TNTQC were studied in Hanks' solution for 192h. The studies showed that the native oxide on the sample is substituted by self assembled nanotube arrays by anodisation. FESEM images of chitosan-loaded TNT samples showed that filling of chitosan takes place in inter-tubular space and pores. Drug release studies revealed that the release of drug into the local environment during that duration was constant. The local concentration of the drug can be controlled and tuned by controlling the thickness of the chitosan (0.6, 1 and 3μm) to fit into an optimal therapeutic window in order to treat postoperative infections, inflammation and for quick healing with better osseointegration of the titanium implants. Copyright © 2016 Elsevier B.V. All rights reserved.

Immune cell impact of three differently coated lipid nanocapsules: pluronic, chitosan and polyethylene glycol.

Science.gov (United States)

Farace, Cristiano; Sánchez-Moreno, Paola; Orecchioni, Marco; Manetti, Roberto; Sgarrella, Francesco; Asara, Yolande; Peula-García, José M; Marchal, Juan A; Madeddu, Roberto; Delogu, Lucia G

2016-01-05

Lipid nanocapsules (NCs) represent promising tools in clinical practice for diagnosis and therapy applications. However, the NC appropriate functionalization is essential to guarantee high biocompatibility and molecule loading ability. In any medical application, the immune system-impact of differently functionalized NCs still remains to be fully understood. A comprehensive study on the action exerted on human peripheral blood mononuclear cells (PBMCs) and major immune subpopulations by three different NC coatings: pluronic, chitosan and polyethylene glycol-polylactic acid (PEG) is reported. After a deep particle characterization, the uptake was assessed by flow-cytometry and confocal microscopy, focusing then on apoptosis, necrosis and proliferation impact in T cells and monocytes. Cell functionality by cell diameter variations, different activation marker analysis and cytokine assays were performed. We demonstrated that the NCs impact on the immune cell response is strongly correlated to their coating. Pluronic-NCs were able to induce immunomodulation of innate immunity inducing monocyte activations. Immunomodulation was observed in monocytes and T lymphocytes treated with Chitosan-NCs. Conversely, PEG-NCs were completely inert. These findings are of particular value towards a pre-selection of specific NC coatings depending on biomedical purposes for pre-clinical investigations; i.e. the immune-specific action of particular NC coating can be excellent for immunotherapy applications.

Chitosan-doped-hybrid/TiO2 nanocomposite based sol-gel coating for the corrosion resistance of aluminum metal in 3.5% NaCl medium.

Science.gov (United States)

J, Balaji; M G, Sethuraman

2017-11-01

The study outlines the role of chitosan, a biopolymer on corrosion behavior of Hy/nano-TiO 2 based sol-gel coating over aluminum metal. In this study organic-inorganic hybrid sols were synthesized through hydrolysis and condensation of 3-glycidoxypropyltrimethoxy silane (GPTMS), tetraethoxysilane (TEOS) and titanium (IV) isopropoxide (TIP) in acidic solution. Chitosan was doped into sol-gel matrix and self-assembled over aluminum substrate. The resultant chitosan-doped-Hy/nano-TiO 2 sol-gel coating was characterized by Fourier Transform Infrared (FT-IR) spectra, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Energy-Dispersive X-ray Spectroscopy (EDX) analyses. The as-tailored aluminum substrate was evaluated for corrosion resistance in neutral medium. The protection ability of these coatings was evaluated by electrochemical impedance studies (EIS) and potentiodynamic polarization (PP) measurements in 3.5% NaCl medium. The EIS and PP results showed that chitosan-doped- Hy/nano-TiO 2 sol-gel coating exhibited better protection from corrosion than the undoped Hy/TiO 2 nanocomposite coating. Copyright © 2017 Elsevier B.V. All rights reserved.

A strong adjuvant based on glycol-chitosan-coated lipid-polymer hybrid nanoparticles potentiates mucosal immune responses against the recombinant Chlamydia trachomatis fusion antigen CTH522

DEFF Research Database (Denmark)

Rose, Fabrice; Erbo Wern, Jeanette; Gavins, Francesca

2018-01-01

with the cationic surfactant dimethyldioctadecylammonium bromide and the immunopotentiator trehalose-6,6'-dibehenate. Here we show that immunization with these lipid-polymer hybrid nanoparticles (LPNs) coated with the mucoadhesive polymer chitosan enhances mucosal immune responses. Glycol chitosan (GC......-specific IgG/IgA antibodies, together with CTH522-specific interferon γ-producing Th1 cells. This study demonstrates that mucosal administration of chitosan-coated LPNs represents a promising strategy to modulate the magnitude of mucosal vaccine responses....

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.

Effect of Graphene and Fullerene Nanofillers on Controlling the Pore Size and Physicochemical Properties of Chitosan Nanocomposite Mesoporous Membranes

Directory of Open Access Journals (Sweden)

Irene S. Fahim

2015-01-01

Full Text Available Chitosan (CS nanocomposite mesoporous membranes were fabricated by mixing CS with graphene (G and fullerene (F nanofillers, and the diffusion properties through CS membranes were studied. In addition, in order to enhance the binding between the internal CS chains, physical cross-linking of CS by sodium tripolyphosphate (TPP was carried out. F and G with different weight percentages (0.1, 0.5, and 1 wt.% were added on physically cross-linked chitosan (CLCS and non-cross-linked chitosan (NCLCS membranes by wet mixing. Permeability and diffusion time of CLCS and NCLCS membranes at different temperatures were investigated. The results revealed that the pore size of all fabricated CS membranes is in the mesoporous range (i.e., 2–50 nm. Moreover, the addition of G and F nanofillers to CLCS and NCLCS solutions aided in controlling the CS membranes’ pore size and was found to enhance the barrier effect of the CS membranes either by blocking the internal pores or decreasing the pore size. These results illustrate the significant possibility of controlling the pore size of CS membranes by cross-linking and more importantly the careful selection of nanofillers and their percentage within the CS membranes. Controlling the pore size of CS membranes is a fundamental factor in packaging applications and membrane technology.

An iodine supplementation of tomato fruits coated with an edible film of the iodide-doped chitosan.

Science.gov (United States)

Limchoowong, Nunticha; Sricharoen, Phitchan; Techawongstien, Suchila; Chanthai, Saksit

2016-06-01

In general, the risk of numerous thyroid cancers inevitably increases among people with iodine deficiencies. An iodide-doped chitosan (CT-I) solution was prepared for dipping tomatoes to coat the fresh surface with an edible film (1.5 μm), thereby providing iodine-rich fruits for daily intake. Characterisation of the thin film was conducted by FTIR and SEM. Stability of the CT-I film was studied via water immersion at various time intervals, and no residual iodide leached out due to intrinsic interactions between the cationic amino group of chitosan and iodide ions. Moreover, the iodide supplement exhibited no effect on the antioxidant activity of tomatoes. The iodine content in the film-coated tomato was determined by ICP-OES. The tomato coating with 1.5% (w/v) CT-I contained approximately 0.4 μg iodide per gram fresh weight. In addition, the freshness and storability of iodine-doped tomatoes were also maintained for shelf-life concerns. Copyright © 2016 Elsevier Ltd. All rights reserved.

CHITOSAN: ANTIBACTERIAL ACTIVITY AND PERSPECTIVES OF THE BIOMEDICAL APPLICATION

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Sukhodub L.B.

2014-10-01

in the Gram-negative bacteria outer membrane are held together by electrostatic interactions with divalent metals. This cations may compete with CS, that also disturb the cell functions. Some authors reported that CS binds to DNA and inhibits RNA synthesis. Significant role in antibacterial activity belongs to the physical and chemical properties of Chitosan, including its cationic structure, molecular weight, degree of the deacetylation, concentration. Owing to the high content of amino and carboxyl groups, Chitosan can form chelate complexes with metals. Silver (Ag ion antimicrobial activity against Gram-negative and Gram-positive bacteria is well known. Complexes Chitosan-Silver are used in medicine for example as part of the protective coatings on metal implants in dentistry and orthopedics in order to reduce the risk of postoperative infection. The antibacterial activity of the Silver-Chitosan-doped hydroxyapatite (HA coating was examined using spectrophotometry by measuring the optical density of the culture medium E.coli АТСС 25922 containing the experimental samples. After 48 hours immersion of the substrate in medium, concentration of microbial cells (C, CFU/ml was decreased from log 7 to log 4,8, what is evidence of the coating antibacterial activity.It was studied the ability of the biomaterials based on HA with Chitosan and Silver content to influence the adhesive properties of E. coli АТСС 25922 and S. aureus АТСС 25923. It was proved that under Ag+ ions action, added to the coating material, the adhesive index for E.coli decreases in relation to formalinized ram erythrocytes on 17 % as compared to control sample (pure HA and the adhesive index for S. aureus – on 13 %. Also was found that chitosan as a component of bioactive coating decreases the adhesive index E. coli on 29 %, and those for S. aureus on 22 %.Thus, from this short overview follows the conclusion that CS can be used in medicine as a very perspective antimicrobial agent. Also

Mucoadhesive properties of low molecular weight chitosan- or glycol chitosan- and corresponding thiomer-coated poly(isobutylcyanoacrylate) core-shell nanoparticles.

Science.gov (United States)

Palazzo, Claudio; Trapani, Giuseppe; Ponchel, Gilles; Trapani, Adriana; Vauthier, Christine

2017-08-01

The aim of the present work was to evaluate the mucoadhesive properties of poly(isobutyl cyanoacrylate) (PIBCA) nanoparticles (NPs) coated with Low Molecular Weight (LMW) chitosan (CS)- and glycol chitosan (GCS)-based thiomers as well as with the corresponding LMW unmodified polysaccharides. For this purpose, all the CS- and GCS-based thiomers were prepared under simple and mild conditions starting from the LMW unmodified polymers CS and GCS. The resulting NPs were of spherical shape with diameters ranging from 400 to 600nm and 187 to 309nm, for CS- and GCS-based NPs, respectively. The mucoadhesive characteristics of these core shell NPs were studied in Ussing chambers measuring the percentage of NPs stuck on the mucosal of fresh intestinal tissue after 2h of incubation. Moreover, incubation of nanoparticle formulations with the intestinal tissue induced changes in transmucosal electrical resistance which were measured to gain information into the opening of tight junctions and to control the integrity of the mucosa. Thus, it was found that PIBCA NPs coated with the GCS-Glutathione conjugate (GCGPIBCA NPs) possessed the most favorable mucoadhesive performances. Moreover, both GCGPIBCA- and GCS-N-acetyl-cysteine (GCNPIBCA)-core-shell NPs might induced an enlargement of the epithelial cell tight junctions. In conclusion, coating of PIBCA NPs with GCS-based thiomers may be useful for improving the mucoadhesive and permeation properties of these nanocarriers. Copyright © 2017 Elsevier B.V. All rights reserved.

Radiation Synthesis of PVA/ Chitosan Membranes Containing Silver Nanoparticles for Biomedical Applications

International Nuclear Information System (INIS)

Elbarbary, A.M.; El-Sawy, N.M.

2015-01-01

Silver Nanoparticles (AgNPs) were synthesized by γ-rays of polyvinyl alcohol/ chitosan (PVA/ CS) membranes containing silver nitrate (AgNO ) with promising antimicrobial and biomedical applications. The synthesized silver nanoparticles characterized by Ultra Violet spectroscopy (UV), Fourier transform infrared (FT-IR), X-ray diffraction (XRD), and transmission electron microscopy (TEM). UV studies showed a strong peak around λmax at 420 nm. A uniform distribution of silver nanoparticles inside PVA/ CS membranes was achieved by TEM investigation. The prepared silver nanoparticles showed good antimicrobial activity. The membranes containing AgNPs showed non-thrombogenicity effect and slightly haemolytic potential. The prepared membranes containing AgNPs had promising use in biomedical applications.

Study on the bonding strength between calcium phosphate/chitosan composite coatings and a Mg alloy substrate

Science.gov (United States)

Zhang, Jie; Dai, Chang-Song; Wei, Jie; Wen, Zhao-Hui

2012-11-01

In order to improve the bonding strength between calcium phosphate/chitosan composite coatings and a micro-arc oxidized (MAO)-AZ91D Mg alloy, different influencing parameters were investigated in the process of electrophoretic deposition (EPD) followed by conversion in a phosphate buffer solution (PBS). Surface morphology and phase constituents of the as-prepared materials were investigated by using X-ray diffractometer (XRD), Fourier-transformed infrared spectrophotometer (FTIR), Raman spectrometer, scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS), and a thermo gravimetric and differential thermal analyzer (TG-DTA). Scratch tests were carried out to study the bonding properties between the coatings and the substrates. In vitro immersion tests were conducted to determine the corrosion behaviors of samples with and without deposit layers through electrochemical experiments. In the EPD process, the acetic acid content in the electrophoresis suspension and the electrophoretic voltage played important roles in improving the bonding properties, while the contents of chitosan (CS) and nano-hydroxyapatite (nHA, Ca10(PO4)6(OH)2) in the suspension had less significant influences on the mechanical bonding strength. It was observed that the coatings showed the excellent bonding property when an electrophoretic voltage was in a range of 40-110 V with other reagent amounts as follows: acetic acid: 4.5 vol.%, CS ≤ 0.25 g, nHA ≤ 2.0 g in 200 ml of a CS-acetic acid aqueous solution and nHA ≤ 2.5 g in 300 ml of absolute ethanol. The morphology of the composite coating obtained under the above optimal condition had a flake-like crystal structure. The EPD in the nHA/CS-acetic acid/ethanol suspension resulted in hydroxyapatite, chitosan, brushite (DCPD, CaHPO4·2H2O) and Ca(OH)2 in the coatings. After the as-prepared coating materials were immersed into PBS, Ca(OH)2 could be converted into HA and DCPD. The results of the electrochemical tests

Laccase-based biocathodes: Comparison of chitosan and Nafion.

Science.gov (United States)

El Ichi-Ribault, S; Zebda, A; Laaroussi, A; Reverdy-Bruas, N; Chaussy, D; Belgacem, M N; Suherman, A L; Cinquin, P; Martin, D K

2016-09-21

Chitosan and Nafion(®) are both reported as interesting polymers to be integrated into the structure of 3D electrodes for biofuel cells. Their advantage is mainly related to their chemical properties, which have a positive impact on the stability of electrodes such as the laccase-based biocathode. For optimal function in implantable applications the biocathode requires coating with a biocompatible semi-permeable membrane that is designed to prevent the loss of enzyme activity and to protect the structure of the biocathode. Since such membranes are integrated into the electrodes ultimately implanted, they must be fully characterized to demonstrate that there is no interference with the performance of the electrode. In the present study, we demonstrate that chitosan provides superior stability compared with Nafion(®) and should be considered as an optimum solution to enhance the biocompatibility and the stability of 3D bioelectrodes. Copyright © 2016 Elsevier B.V. All rights reserved.

The Modification of PVDF Membrane via Crosslinking with Chitosan and Glutaraldehyde as the Crosslinking Agent

OpenAIRE

Silitonga, Romaya Sitha; Widiastuti, Nurul; Jaafar, Juhana; Ismail, Ahmad Fauzi; Abidin, Muhammad Nidzhom Zainol; Azelee, Ihsan Wan; Naidu, Mahesan

2018-01-01

Poly(vinylidene fluoride) (PVDF) has outstanding properties such as high thermal stability, resistance to acid solvents and good mechanical strength. Due to its properties, PVDF is widely used as a membrane matrix. However, PVDF membrane is hydrophobic properties, so as for specific applications, the surface of membrane needs to be modified to become hydrophilic. This research aims to modify PVDF membrane surface with chitosan and glutaraldehyde as a crosslinker agent. The FTIR spectra showed...

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

Science.gov (United States)

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

2016-02-01

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

Development of chitosan-coated gold nanoflowers as SERS-active probes

Science.gov (United States)

Xu, Dan; Gu, Jiangjiang; Wang, Weina; Yu, Xuehai; Xi, Kai; Jia, Xudong

2010-09-01

Surface-enhanced Raman scattering (SERS) has been intensely researched for many years as a potential technique for highly sensitive detection. This work, through the reduction of HAuCl4 with pyrrole in aqueous solutions, investigated a facile one-pot synthesis of flower-like Au nanoparticles with rough surfaces. The formation process of the Au nanoflowers (AuNFs) was carefully studied, and a spontaneous assembly mechanism was proposed based on the time-course experimental results. The key synthesis strategy was to use pyrrole as a weak particle stabilizing and reducing agent to confine crystal growth in the limited ligand protection region. The nanometer-scale surface roughness of AuNFs provided several hot spots on a single particle, which significantly increased SERS enhancement. Good biocompatible stable Raman-active probes were synthesized by coating AuNFs with chitosan. The conservation of the SERS effects in living cells suggested that the chitosan-capped AuNFs could be suitable for highly sensitive detection and have potential for targeting of tumors in vivo.

Enhanced bonding of chitosan to implant quality titanium via four treatment combinations

Energy Technology Data Exchange (ETDEWEB)

Martin, Holly J. [Dave C. Swalm School of Chemical Engineering, James Worth Bagley College of Engineering, Mississippi State University, Box 9595, Mississippi State, Mississippi 39762 (United States)], E-mail: hjp2@msstate.edu; Schulz, Kirk H. [Dave C. Swalm School of Chemical Engineering, James Worth Bagley College of Engineering, Mississippi State University, Box 9595, Mississippi State, Mississippi 39762 (United States); Bumgardner, Joel D. [Department of Biomedical Engineering, Herff College of Engineering, University of Memphis, 330 Engineering Technology Building, Memphis, Tennessee 38152 (United States); Schneider, Judith A. [Department of Mechanical Engineering, James Worth Bagley College of Engineering, Mississippi State University, Box 9552, Mississippi State, Mississippi 39762 (United States)

2008-07-31

Bioactive coatings have been investigated to enhance the integration of orthopaedic and dental-craniofacial implants in the surrounding bone tissue. Chitosan has been shown to possess many properties desirable in implant coatings, such as cell attachment and growth, and encouraging ordered bone tissue formation. Previous studies have produced methods to deposit chitosan onto a titanium surface using both two-step and three-step reaction schemes. In the current study, two different titanium surface treatments were evaluated for determining the strength of chitosan coatings bonded to titanium via two reaction processes. The chitosan coatings produced from the four treatment combinations were examined using X-ray Photoelectron Spectroscopy, which demonstrated that the final coatings were similar in composition to the previously reported coatings. Coatings examined by nano-indentation, exhibited hardness (0.19 {+-} 0.08 GPa) and elastic modulus (4.90 {+-} 1.82 GPa) values similar to the hardness and elastic modulus values previously reported. Scanning Electron Microscopy examination of the nano-indentation marks revealed cracks only at sites of applied stress, demonstrating that the chitosan coatings were able to absorb the applied stress. Bulk adhesion of the chitosan coatings demonstrated significant increases in bond strength (19.50 {+-} 1.63 MPa) over previously reported data (1.5-1.8 MPa), but no significant differences were seen between the four treatment combinations. Contact angle testing demonstrated that the chitosan coatings were more hydrophobic (98.0 {+-} 3.6 deg.) than published values (76.4 {+-} 5.1 deg.). Overall, mechanical testing demonstrated that, while the bulk properties of the chitosan coating were unaffected by the four treatment combinations, the bulk adhesion of the chitosan coating was greatly increased and high quality coatings were produced.

Two-Ply Composite Membranes with Separation Layers from Chitosan and Sulfoethylcellulose on a Microporous Support Based on Poly(diphenylsulfone-N-phenylphthalimide

Directory of Open Access Journals (Sweden)

Svetlana V. Kononova

2017-12-01

Full Text Available Two-ply composite membranes with separation layers from chitosan and sulfoethylcellulose were developed on a microporous support based on poly(diphenylsulfone-N-phenylphthalimide and investigated by use of X-ray diffraction and scanning electron microscopy methods. The pervaporation properties of the membranes were studied for the separation of aqueous alcohol (ethanol, propan-2-ol mixtures of different compositions. When the mixtures to be separated consist of less than 15 wt % water in propan-2-ol, the membranes composed of polyelectrolytes with the same molar fraction of ionogenic groups (-NH3+ for chitosan and -SO3− for sulfoethylcellulose show high permselectivity (the water content in the permeate was 100%. Factors affecting the structure of a non-porous layer of the polyelectrolyte complex formed on the substrate surface and the contribution of that complex to changes in the transport properties of membranes are discussed. The results indicate significant prospects for the use of chitosan and sulfoethylcellulose for the formation of highly selective pervaporation membranes.

Enhanced bonding of chitosan to implant quality titanium via four treatment combinations

International Nuclear Information System (INIS)

Martin, Holly J.; Schulz, Kirk H.; Bumgardner, Joel D.; Schneider, Judith A.

2008-01-01

Bioactive coatings have been investigated to enhance the integration of orthopaedic and dental-craniofacial implants in the surrounding bone tissue. Chitosan has been shown to possess many properties desirable in implant coatings, such as cell attachment and growth, and encouraging ordered bone tissue formation. Previous studies have produced methods to deposit chitosan onto a titanium surface using both two-step and three-step reaction schemes. In the current study, two different titanium surface treatments were evaluated for determining the strength of chitosan coatings bonded to titanium via two reaction processes. The chitosan coatings produced from the four treatment combinations were examined using X-ray Photoelectron Spectroscopy, which demonstrated that the final coatings were similar in composition to the previously reported coatings. Coatings examined by nano-indentation, exhibited hardness (0.19 ± 0.08 GPa) and elastic modulus (4.90 ± 1.82 GPa) values similar to the hardness and elastic modulus values previously reported. Scanning Electron Microscopy examination of the nano-indentation marks revealed cracks only at sites of applied stress, demonstrating that the chitosan coatings were able to absorb the applied stress. Bulk adhesion of the chitosan coatings demonstrated significant increases in bond strength (19.50 ± 1.63 MPa) over previously reported data (1.5-1.8 MPa), but no significant differences were seen between the four treatment combinations. Contact angle testing demonstrated that the chitosan coatings were more hydrophobic (98.0 ± 3.6 deg.) than published values (76.4 ± 5.1 deg.). Overall, mechanical testing demonstrated that, while the bulk properties of the chitosan coating were unaffected by the four treatment combinations, the bulk adhesion of the chitosan coating was greatly increased and high quality coatings were produced

Wound healing properties of PVA/starch/chitosan hydrogel membranes with nano Zinc oxide as antibacterial wound dressing material.

Science.gov (United States)

Baghaie, Shaghayegh; Khorasani, Mohammad T; Zarrabi, Ali; Moshtaghian, Jamal

2017-12-01

In this work, hydrogel membranes were developed based on poly vinyl alcohol (PVA), starch (St), and chitosan (Cs) hydrogels with nano Zinc oxide (nZnO). PVA/St/Cs/nZnO hydrogel membranes were prepared by freezing-thawing cycles, and the aqueous PVA/St solutions were prepared by dissolving PVA in distilled water. After the dissolution of PVA, starch was mixed, and the mixture was stirred. Then, chitosan powder was added into acetic acid, and the mixture was stirred to form a chitosan solution. Subsequently, Cs, St and PVA solutions were blended together to form a homogeneous PVA/St/Cs ternary blend solution. Measurement of Equilibrium Swelling Ratio (ESR), Water Vapor Transmission Test (WVTR), mechanical properties, scanning electron microscopy (SEM), MTT [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide] assay, antibacterial studies, in vivo wound healing effect and histopathology of the hydrogel membranes were then performed. The examination revealed that the hydrogel membranes were more effective as a wound dressing in the early stages of wound healing and that the gel could be used in topic applications requiring a large spectrum of antibacterial activity; namely, as a bandage for wound dressing.

Functionalization of a Hydrophilic Commercial Membrane Using Inorganic-Organic Polymers Coatings for Membrane Distillation

Directory of Open Access Journals (Sweden)

Lies Eykens

2017-06-01

Full Text Available Membrane distillation is a thermal separation technique using a microporous hydrophobic membrane. One of the concerns with respect to the industrialization of the technique is the development of novel membranes. In this paper, a commercially available hydrophilic polyethersulfone membrane with a suitable structure for membrane distillation was modified using available hydrophobic coatings using ORMOCER® technology to obtain a hydrophobic membrane that can be applied in membrane distillation. The surface modification was performed using a selection of different components, concentrations, and application methods. The resulting membranes can have two hydrophobic surfaces or a hydrophobic and hydrophilic surface depending on the application method. An extensive characterization procedure confirmed the suitability of the coating technique and the obtained membranes for membrane distillation. The surface contact angle of water could be increased from 27° up to 110°, and fluxes comparable to membranes commonly used for membrane distillation were achieved under similar process conditions. A 100 h test demonstrated the stability of the coating and the importance of using sufficiently stable base membranes.

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

Directory of Open Access Journals (Sweden)

Pauline Renoud

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

Fabrication and Characterization of Chitosan Nanoparticle-Incorporated Quaternized Poly(Vinyl Alcohol) Composite Membranes as Solid Electrolytes for Direct Methanol Alkaline Fuel Cells

International Nuclear Information System (INIS)

Li, Pin-Chieh; Liao, Guan–Ming; Kumar, S. Rajesh; Shih, Chao-Ming; Yang, Chun-Chen; Wang, Da-Ming; Lue, Shingjiang Jessie

2016-01-01

Highlights: • Preparation of chitosan nanoparticles from bulk to enhance the degree of deacetylation. • The incorporation of chitosan nanoparticles into a QPVA matrix to form a nanocomposite membrane. • The nanocomposite constructed into thin-film membranes using the solution casting method. • To improve permeability, glutaraldehyde was cross-linked with the nanocomposite membranes. • A direct methanol alkaline fuel cell was studied at different temperatures. - Abstract: In this study, we designed a method for the preparation of chitosan nanoparticles incorporated into a quaternized poly(vinyl alcohol) (QPVA) matrix for direct methanol alkaline fuel cells (DMAFCs). The structural and morphological properties of the prepared nanocomposites were studied using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscope (TEM) and dynamic laser-light scattering (DLS). The crystallinity of the nanocomposite solid electrolytes containing 0 and 10% chitosan nanoparticles were investigated using differential scanning calorimetry (DSC). The electrochemical measurement of resulting nanocomposite membranes were analyzed according to the following parameters: methanol permeability, liquid uptakes, ionic conductivity and cell performances. The composite membranes with 10% chitosan nanoparticles in a QPVA matrix (CQPVA) show suppressed methanol permeability and higher ionic conductivity than pristine QPVA. In addition, the glutaraldehyde cross-linked nanocomposite film exhibited improvement on the methanol barrier property at 80 °C. The peak power density of the DMAFCs reached 67 mW cm −2 when fed into 1 M of methanol in 6 M of KOH.

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.

Preparation of silver-chitosan nanocomposites and coating on bandage for antibacterial wound dressing application

Energy Technology Data Exchange (ETDEWEB)

Susilowati, Endang, E-mail: endwati@yahoo.co.id; Ashadi [Chemistry Education Department, Faculty of Teacher Training and Education, Universitas Sebelas Maret Surakarta (Indonesia); Maryani [Medical Doctor Program, Faculty of Medicine, Universitas Sebelas Maret Surakarta, Indonesia Jl. Ir Sutami 36 A Surakarta Indonesia 53126 (Indonesia)

2016-02-08

Bandage is a medical device that is essential for wound dressing. To improve the performance of the bandage, it has been coated by silver-chitosan nanocomposites (Ag/Chit) with pad-dry-cure method. The nanocomposites were performed by chemical reduction method at room temperature using glucose as reducing agent, sodium hydroxide (NaOH) as accelerator reagent, silver nitrate (AgNO{sub 3}) as metal precursor and chitosan as stabilizing agent. Localized surface plasmon resonance (LSPR) absorption band of silver nanoparticles was investigated using UV-Vis spectrophotometer. The bandage coated Ag/Chit nanocomposites (B-Ag/Chit) were characterized by fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM). In addition, antibacterial activity of the bandage toward Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli) were also studied. The formation of silver nanoparticles was confirmed by the appearance of LSPR absorption peak at 412.2 – 423.2 nm. Coating of nanocomposite cause increasing rigidity of bandage and decreasing on crystallinity. The bandages of B-Ag/Chit demonstrated good activity against both Gram positive (S. aureus) and Gram negative (E.Coli). Thus the bandages have a potential to be used for antibacterial wound dressing application.

Tailored freestanding multilayered membranes based on chitosan and alginate.

Science.gov (United States)

Silva, Joana M; Duarte, Ana Rita C; Caridade, Sofia G; Picart, Catherine; Reis, Rui L; Mano, João F

2014-10-13

Engineering metabolically demanding tissues requires the supply of nutrients, oxygen, and removal of metabolic byproducts, as well as adequate mechanical properties. In this work, we propose the development of chitosan (CHIT)/alginate (ALG) freestanding membranes fabricated by layer-by-layer (LbL) assembly. CHIT/ALG membranes were cross-linked with genipin at a concentration of 1 mg·mL(-1) or 5 mg·mL(-1). Mass transport properties of glucose and oxygen were evaluated on the freestanding membranes. The diffusion of glucose and oxygen decreases with increasing cross-linking concentration. Mechanical properties were also evaluated in physiological-simulated conditions. Increasing cross-linking density leads to an increase of storage modulus, Young modulus, and ultimate tensile strength, but to a decrease in the maximum hydrostatic pressure. The in vitro biological performance demonstrates that cross-linked films are more favorable for cell adhesion. This work demonstrates the versatility and feasibility of LbL assembly to generate nanostructured constructs with tunable permeability, mechanical, and biological properties.

Comparative Study of One-Step Cross-Linked Electrospun Chitosan-Based Membranes

Directory of Open Access Journals (Sweden)

Yanet E. Aguirre-Chagala

2017-01-01

Full Text Available Chitosan membranes are widely applied for tissue engineering; however, a major drawback is their low resistance in aqueous phases and therefore the structure collapses impeding their long-term use. Although there is extensive research, because of chitosan’s importance as a biomaterial, studies involving chitosan-based membranes are still needed. Herein, a detailed investigation of diverse chemical routes to cross-link fibers in situ by electrospinning process is described. In case of using genipin as cross-linker, a close relationship with the content and the mean diameter values is reported, suggesting a crucial effect over the design of nanostructures. Also, the physical resistance is enhanced for the combination of two types of methods, such as chemical and physical methods. Cross-linked fibers upon exposure to long wave ultraviolet A (UVA light change their morphology, but not their chemical composition. When they are incubated in aqueous phase for 70 days, they show an extensive improvement of their macrostructural integrity which makes them attractive candidates for tissue engineering application. As a result, the thermal properties of these materials reveal less crystallinity and higher temperature of degradation.

Coating of reverse osmosis membranes with amphiphilic copolymers for biofouling control

KAUST Repository

Bucs, Szilard

2017-05-30

Surface coating of membranes may be a promising option to control biofilm development and biofouling impact on membrane performance of spiral-wound reverse osmosis (RO) systems. The objective of this study was to investigate the impact of an amphiphilic copolymer coating on biofilm formation and biofouling control. The coating was composed of both hydrophilic and hydrophobic monomers hydroxyethyl methacrylate (HEMA) and perfluorodecyl acrylate (PFA), respectively. Commercial RO membranes were coated with HEMA-PFA copolymer film. Long and short term biofouling studies with coated and uncoated membranes and feed spacer were performed using membrane fouling simulators (MFSs) operated in parallel, fed with water containing nutrients. For the long-term studies pressure drop development in time was monitored and after eight days the MFSs were opened and the accumulated biofilm on the membrane and spacer sheets was quantified and characterized. The presence of the membrane coating was determined using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Results showed that the amphiphilic coating (i) delayed biofouling (a lower pressure drop increase by a factor of 3 and a lower accumulated active biomass amount by a factor of 6), (ii) influenced the biofilm composition (23% lower polysaccharides and 132% higher protein content) and (iii) was still completely present on the membrane at the end of the biofouling study, showing that the coating was strongly attached to the membrane surface. Using coated membranes and feed spacers in combination with advanced cleaning strategies may be a suitable way to control biofouling.

Coating of reverse osmosis membranes with amphiphilic copolymers for biofouling control

KAUST Repository

Bucs, Szilard; Valladares Linares, Rodrigo; Siddiqui, Amber; Matin, Asif; Khan, Zafarullah; van Loosdrecht, Mark C.M.; Yang, Rong; Wang, Minghui; Gleason, Karen K.; Kruithof, Joop C.; Vrouwenvelder, Johannes S.

2017-01-01

Surface coating of membranes may be a promising option to control biofilm development and biofouling impact on membrane performance of spiral-wound reverse osmosis (RO) systems. The objective of this study was to investigate the impact of an amphiphilic copolymer coating on biofilm formation and biofouling control. The coating was composed of both hydrophilic and hydrophobic monomers hydroxyethyl methacrylate (HEMA) and perfluorodecyl acrylate (PFA), respectively. Commercial RO membranes were coated with HEMA-PFA copolymer film. Long and short term biofouling studies with coated and uncoated membranes and feed spacer were performed using membrane fouling simulators (MFSs) operated in parallel, fed with water containing nutrients. For the long-term studies pressure drop development in time was monitored and after eight days the MFSs were opened and the accumulated biofilm on the membrane and spacer sheets was quantified and characterized. The presence of the membrane coating was determined using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Results showed that the amphiphilic coating (i) delayed biofouling (a lower pressure drop increase by a factor of 3 and a lower accumulated active biomass amount by a factor of 6), (ii) influenced the biofilm composition (23% lower polysaccharides and 132% higher protein content) and (iii) was still completely present on the membrane at the end of the biofouling study, showing that the coating was strongly attached to the membrane surface. Using coated membranes and feed spacers in combination with advanced cleaning strategies may be a suitable way to control biofouling.

Composite Membrane with Underwater-Oleophobic Surface for Anti-Oil-Fouling Membrane Distillation.

Science.gov (United States)

Wang, Zhangxin; Hou, Deyin; Lin, Shihong

2016-04-05

In this study, we fabricated a composite membrane for membrane distillation (MD) by modifying a commercial hydrophobic polyvinylidene fluoride (PVDF) membrane with a nanocomposite coating comprising silica nanoparticles, chitosan hydrogel and fluoro-polymer. The composite membrane exhibits asymmetric wettability, with the modified surface being in-air hydrophilic and underwater oleophobic, and the unmodified surface remaining hydrophobic. By comparing the performance of the composite membrane and the pristine PVDF membrane in direct contact MD experiments using a saline emulsion with 1000 ppm crude oil (in water), we showed that the fabricated composite membrane was significantly more resistant to oil fouling compared to the pristine hydrophobic PVDF membrane. Force spectroscopy was conducted for the interaction between an oil droplet and the membrane surface using a force tensiometer. The difference between the composite membrane and the pristine PVDF membrane in their interaction with an oil droplet served to explain the difference in the fouling propensities between these two membranes observed in MD experiments. The results from this study suggest that underwater oleophobic coating can effectively mitigate oil fouling in MD operations, and that the fabricated composite membrane with asymmetric wettability can enable MD to desalinate hypersaline wastewater with high concentrations of hydrophobic contaminants.

Chitosan/Carboxymethylcellulose/Ionic Liquid/Ag(0) Nanoparticles Form a Membrane with Antimicrobial Activity

International Nuclear Information System (INIS)

Quadros, C.; Faria, V.W.; Scheeren, C.W.; Klein, M.P.; Hertz, P.F.

2013-01-01

Silver metal nanoparticles were immobilized in chitosan/carboxymethylcellulose/BMI.BF4(1-n-butyl-3-methylimidazolium tetrafluoroborate ionic liquid) (CS/CMC/IL) to form polymeric membrane with 20 μm thickness. The CS/CMC/IL polymeric membrane was prepared using a simple solution blending method. Irregularly shaped Ag(0) nanoparticles with monomodal size distributions of nm Ag(0) were immobilized in the membrane. The presence of small Ag(0) nanoparticles induced an augmentation in the CS/CMC/IL film surface areas. The CS/CMC/IL membrane containing Ag(0) showed increase antimicrobial activity the Ag(0) concentration increased up to saturation at 10 mg. CS/CMC/IL membrane that contains Ag(0) nanoparticles has enhanced durability of the membrane and exhibited stronger antimicrobial activity against Escherichia coli and Staphylococcus aureus.

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.

Preparation and characterization of dutasteride-loaded nanostructured lipid carriers coated with stearic acid-chitosan oligomer for topical delivery.

Science.gov (United States)

Noor, Norhayati Mohamed; Sheikh, Khalid; Somavarapu, Satyanarayana; Taylor, Kevin M G

2017-08-01

Dutasteride, used for treating benign prostate hyperplasia (BPH), promotes hair growth. To enhance delivery to the hair follicles and reduce systemic effects, in this study dutasteride has been formulated for topical application, in a nanostructured lipid carrier (NLC) coated with chitosan oligomer-stearic acid (CSO-SA). CSO-SA has been successfully synthesized, as confirmed using 1 H NMR and FTIR. Formulation of dutasteride-loaded nanostructured lipid carriers (DST-NLCs) was optimized using a 2 3 full factorial design. This formulation was coated with different concentrations of stearic acid-chitosan solution. Coating DST-NLCs with 5% SA-CSO increased mean size from 187.6±7.0nm to 220.1±11.9nm, and modified surface charge, with zeta potentials being -18.3±0.9mV and +25.8±1.1mV for uncoated and coated DST-NLCs respectively. Transmission electron microscopy showed all formulations comprised approximately spherical particles. DST-NLCs, coated and uncoated with CSO-SA, exhibited particle size stability over 60days, when stored at 4-8°C. However, NLCs coated with CSO (without conjugation) showed aggregation when stored at 4-8°C after 30days. The measured particle size for all formulations stored at 25°C suggested aggregation, which was greatest for DST-NLCs coated with 10% CSO-SA and 5% CSO. All nanoparticle formulations exhibited rapid release in an in vitro release study, with uncoated NLCs exhibiting the fastest release rate. Using a Franz diffusion cell, no dutasteride permeated through pig ear skin after 48h, such that it was not detected in the receptor chamber for all samples. The amount of dutasteride in the skin was significantly different (pchitosan conjugate was successfully prepared, and modified the surface charge of DST-NLCs from negative to positive. These stable, less cytotoxic, positively-charged dutasteride-loaded nanostructured lipid carriers, with stearic acid-chitosan oligomer conjugate, are appropriate for topical delivery and have

In vitro evaluation of chitosan coated- and uncoated-calcium alginate beads containing methyl salicylate-lactose physical mixture.

Science.gov (United States)

Tamilvanan, S; Karmegam, S

2012-01-01

Methyl salicylate-lactose physical mixture (1:1 and 1:1.5 ratios) was incorporated into calcium alginate beads by a coacervation method involving an ionotropic gelation/polyelectrolyte complexation approach. This study aims to determine the influence of chitosan coating over the beads on drug entrapment efficiency (DEE) and release characteristics in artificial saliva compared to that of the uncoated beads. Changes in formulation parameters (gelation time, concentrations of Ca(2+) and alginate) resulted in decrease in DEE of chitosan-uncoated beads (p methyl salicylate-lactose physical mixture.

Effects of Aloe Vera and Chitosan Nanoparticle Thin-Film Membranes on Wound Healing in Full Thickness Infected Wounds with Methicillin Resistant Staphylococcus Aureus.

Science.gov (United States)

Ranjbar, Reza; Yousefi, Alireza

2018-01-01

To assess effect of Aleo vera with chitosan nanoparticle biofilm on wound healing in full thickness infected wounds with antibiotic resistant gram positive bacteria. Thirty rats were randomized into five groups of six rats each. Group I: Animals with uninfected wounds treated with 0.9% saline solution. Group II: Animals with infected wounds treated with saline. Group III: Animals with infected wounds were dressed with chitosan nanoparticle thin-film membranes. Group IV: Animals with infected wounds were treated topically with Aloe vera and Group V: Animals with infected wounds were treated topically with Aloe vera and dressed with chitosan nanoparticle thin-film membranes. Wound size was measured on 6, 9, 12, 15, 18 and 21days after surgery. Microbiology, reduction in wound area and hydroxyproline contents indicated that there was significant difference ( p vera with chitosan nanoparticle thin-film membranes had a reproducible wound healing potential and hereby justified its use in practice.

Preparation and Evaluation of Enteric-Coated Chitosan Derivative-Based Microparticles Loaded with Salmon Calcitonin as an Oral Delivery System

Directory of Open Access Journals (Sweden)

Hiraku Onishi

2016-09-01

Full Text Available Background: The production of protein drugs has recently increased due to advances in biotechnology, but their clinical use is generally limited to parenteral administration due to low absorption in non-parenteral administration. Therefore, non-parenteral delivery systems allowing sufficient absorption draw much attention. Methods: Microparticles (MP were prepared using chitosan-4-thio-butylamidine conjugate (Ch-TBA, trimethyl-chitosan (TMC, and chitosan (Ch. Using salmon calcitonin (sCT as a model protein drug, Ch-TBA-, Ch-TBA/TMC (4/1-, and Ch-based MP were produced, and their Eudragit L100 (Eud-coated MP, named Ch-TBA-MP/Eud, Ch-TBA/TMC-MP/Eud, and Ch-MP/Eud, respectively, were prepared as oral delivery systems. These enteric-coated microparticles were examined in vitro and in vivo. Results: All microparticles before and after enteric coating had a submicron size (600–800 nm and micrometer size (1300–1500 nm, respectively. In vitro release patterns were similar among all microparticles; release occurred gradually, and the release rate was slower at pH 1.2 than at pH 6.8. In oral ingestion, Ch-TBA-MP/Eud suppressed plasma Ca levels most effectively among the microparticles tested. The relative effectiveness of Ch-TBA-MP/Eud to the intramuscular injection was 8.6%, while the sCT solution showed no effectiveness. Conclusion: The results suggest that Eud-coated Ch-TBA-based microparticles should have potential as an oral delivery system of protein drugs.

Inactivation of Salmonella in tomato stem scars by organic acid wash and chitosan-allyl isothiocyanate coating

Science.gov (United States)

The objective of this study was to evaluate inactivation of inoculated Salmonella enterica on tomato stem scars exploiting integrated treatment of organic acid wash (AW) followed by chitosan-allyl isothiocyanate (CT-AIT) coating. The treatment effect on microbial loads and fruit quality during 21 d...

Chitosan-limonene coating in combination with modified atmosphere packaging preserve postharvest quality of cucumber during storage

NARCIS (Netherlands)

Maleki, Gisoo; Sedaghat, Naser; Woltering, Ernst J.; Farhoodi, Mehdi; Mohebbi, Mohebbat

2018-01-01

Since cucumbers suffer from a short postharvest life, applying different technologies is increasingly used as effective ways to increase their shelf life and quality. In this study a combination of chitosan-limonene coating and MAP storage has been used as a postharvest treatment to maintain

Collagen-chitosan-glycerol bio-composite as artificial tympanic membrane for ruptured inner ear organ

Science.gov (United States)

Widiyanti, Prihartini; Setya Angtika, Rara; Githanadi, Brillyana; Hanif Kharisma, Ditya; Asyraf, Tarikh Omar; Wardani, Adita

2017-05-01

WHO data in 2012 shows that 5.3% of world population highly suffers from hearing loss and deafness. One of the deafness causes is rupture of tympanic membrane. Tympanic membrane damage which occurs often is perforated tympanic membrane, and it is also commonly known in medical term as tympanic membrane perforation. The causes, for instance, are high frequency of using earphones, traumatic accidents, noise, bacteria, viruses, and infectious microorganism. Tympanoplasty becomes the only treatment that can be widely accepted despite of deficiencies in postoperative complications. Therefore, this research aims to create artificial tympanic membrane made of natural materials such as type I collagen composited with chitosan and made of addition of glycerol to improve its mechanical strength and biodegradability. The method included the process of dissolving acetic acid in distilled water and mixation with chitosan. The solution is next added with glycerol and stirred to be homogeneous. After that, it was minted in petri dish and aerated before characterized. The sample characterization included tensile strength of which tensile test results showed that the value of the elasticity modulus tended to decrease with an increase in collagen concentration. The elasticity modulus values in a row for the variations of 7: 3, 8: 2, and 9: 1 were 35.10 MPa, 54,52MPa, and 47,45MPa respectively. The morphological test with 1000x, 2500x, and 5000x magnification showed their interaction in the formation of pores. Cytotoxicity results, moreover, showed that those samples were non-toxic and safe for the body due to the percentage of living cells. The sound absorption coefficient was between 1000 Hz - 2000 Hz which means that it could use as sound absorbing material. The antibacterial test results showed that all the sample variations were anti-bacterial due to the diameter of the clear zone. In conclusion, collagen and chitosan composite with addition of glycerol could be used for

Freestanding Artificial Synapses Based on Laterally Proton-Coupled Transistors on Chitosan Membranes.

Science.gov (United States)

Liu, Yang Hui; Zhu, Li Qiang; Feng, Ping; Shi, Yi; Wan, Qing

2015-10-07

Freestanding synaptic transistors are fabricated on solution-processed chitosan membranes. A short-term memory to long-term memory transition is observed due to proton-related electrochemical doping under repeated pulse stimulus. Moreover, freestanding artificial synaptic devices with multiple presynaptic inputs are investigated, and spiking logic operation and logic modulation are realized. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Surface modification of an Mg-1Ca alloy to slow down its biocorrosion by chitosan

International Nuclear Information System (INIS)

Gu, X N; Zheng, Y F; Lan, Q X; Cheng, Y; Xi, T F; Zhang, Z X; Zhang, D Y

2009-01-01

The surface morphologies before and after immersion corrosion test of various chitosan-coated Mg-1Ca alloy samples were studied to investigate the effect of chitosan dip coating on the slowdown of biocorrosion. It showed that the corrosion resistance of the Mg-Ca alloy increased after coating with chitosan, and depended on both the chitosan molecular weight and layer numbers of coating. The Mg-Ca alloy coated by chitosan with a molecular weight of 2.7 x 10 5 for six layers has smooth and intact surface morphology, and exhibits the highest corrosion resistance in a simulated body fluid.

Surface modification of an Mg-1Ca alloy to slow down its biocorrosion by chitosan

Energy Technology Data Exchange (ETDEWEB)

Gu, X N; Zheng, Y F; Lan, Q X [State Key Laboratory for Turbulence and Complex System and College of Engineering, Peking University, Beijing 100871 (China); Cheng, Y; Xi, T F [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zhang, Z X [Biomedical Engineering Research Center, Research Institute of Peking University in Shenzhen, Shenzhen 518057 (China); Zhang, D Y, E-mail: gxn139888@pku.edu.c, E-mail: yfzheng@pku.edu.c, E-mail: 8lanqiuxiang@163.co, E-mail: chengyan@pku.edu.c, E-mail: top5460@163.co, E-mail: xitingfei@tom.co, E-mail: zhangdeyuan@lifetechmed.co [Lifetech Scientific (Shenzhen) Co. Ltd, Hi-Tech Park, Shenzhen 518000 (China)

2009-08-15

The surface morphologies before and after immersion corrosion test of various chitosan-coated Mg-1Ca alloy samples were studied to investigate the effect of chitosan dip coating on the slowdown of biocorrosion. It showed that the corrosion resistance of the Mg-Ca alloy increased after coating with chitosan, and depended on both the chitosan molecular weight and layer numbers of coating. The Mg-Ca alloy coated by chitosan with a molecular weight of 2.7 x 10{sup 5} for six layers has smooth and intact surface morphology, and exhibits the highest corrosion resistance in a simulated body fluid.

Surface modification of an Mg-1Ca alloy to slow down its biocorrosion by chitosan.

Science.gov (United States)

Gu, X N; Zheng, Y F; Lan, Q X; Cheng, Y; Zhang, Z X; Xi, T F; Zhang, D Y

2009-08-01

The surface morphologies before and after immersion corrosion test of various chitosan-coated Mg-1Ca alloy samples were studied to investigate the effect of chitosan dip coating on the slowdown of biocorrosion. It showed that the corrosion resistance of the Mg-Ca alloy increased after coating with chitosan, and depended on both the chitosan molecular weight and layer numbers of coating. The Mg-Ca alloy coated by chitosan with a molecular weight of 2.7 x 10(5) for six layers has smooth and intact surface morphology, and exhibits the highest corrosion resistance in a simulated body fluid.

Cinnamon Oil and Chitosan Coating on Orthopaedic Implant Surface for Prevention of Staphylococcus Epidermidis Biofilm Formation

OpenAIRE

R Magetsari; P Dewo; BK Saputro; Z Lanodiyu

2014-01-01

S. Epidermidis is among the most frequently isolated microorganisms found in -infection related to implanted devices and the formation of biofilm will be more resistantcompared to the planktonic form. This study was carried out determine the effect of coating on stainless steel orthopaedic implants surfaces with cinnamon oil and chitosan as bioadhesive to prevent biofilms formation of S. Epidermidis.The rod shaped stainless steel 316 L orthopaedic implant with 5 mm diameters was coated 2 t...

Hyaluronic acid-coated chitosan nanoparticles: molecular weight-dependent effects on morphology and hyaluronic acid presentation.

Science.gov (United States)

Almalik, Abdulaziz; Donno, Roberto; Cadman, Christopher J; Cellesi, Francesco; Day, Philip J; Tirelli, Nicola

2013-12-28

Chitosan nanoparticles are popular carriers for the delivery of macromolecular payloads, e.g. nucleic acids. In this study, nanoparticles were prepared via complexation with triphosphate (TPP) anions and were successively coated with hyaluronic acid (HA). Key variables of the preparative process (e.g. chitosan and HA molecular weight) were optimised in view of the maximisation of loading with DNA, of the Zeta potential and of the dimensional stability, and the resulting particles showed excellent storage stability. We have focused on the influence of chitosan molecular weight on nanoparticle properties. Larger molecular weight increased their porosity (=decreased cross-link density), and this caused also larger dimensional changes in response to variations in osmotic pressure or upon drying. The dependency of nanoparticle porosity on chitosan molecular weight had a profound effect on the adsorption of HA on the nanoparticles; HA was apparently able to penetrate deeply into the more porous high molecular weight (684 kDa) chitosan nanoparticles, while it formed a corona around those composed of more densely cross-linked low molecular weight (25 kDa) chitosan. Atomic Force Microscopy (AFM) allowed not only to highlight the presence of this corona, but also to estimate its apparent thickness to about 20-30 nm (in a dry state). The different morphology has a significant effect on the way HA is presented to biomolecules, and this has specific relevance in relation to interactions with HA receptors (e.g. CD44) that influence kinetics and mechanism of nanoparticle uptake. Finally, it is worth to mention that chitosan molecular weight did not appear to greatly affect the efficiency of nanoparticle loading with DNA, but significantly influenced its chitosanase-triggered release, with high molecular chitosan nanoparticles seemingly more prone to degradation by this enzyme. © 2013.

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.

Antibacterial effects of electrospun chitosan/poly(ethylene oxide) nanofibrous membranes loaded with chlorhexidine and silver

NARCIS (Netherlands)

Song, J.; Remmers, S.J.; Shao, J.; Kolwijck, E.; Walboomers, X.F.; Jansen, J.A.; Leeuwenburgh, S.C.; Yang, F.

2016-01-01

To prevent percutaneous device associated infections (PDAIs), we prepared electrospun chitosan/poly(ethylene oxide) (PEO) nanofibrous membrane containing silver nanoparticles as an implantable delivery vehicle for the dual release of chlorhexidine and silver ions. We observed that the silver

Acquisition of epithelial-mesenchymal transition and cancer stem-like phenotypes within chitosan-hyaluronan membrane-derived 3D tumor spheroids.

Science.gov (United States)

Huang, Yen-Jang; Hsu, Shan-Hui

2014-12-01

Cancer drug development has to go through rigorous testing and evaluation processes during pre-clinical in vitro studies. However, the conventional two-dimensional (2D) in vitro culture is often discounted by the insufficiency to present a more typical tumor microenvironment. The multicellular tumor spheroids have been a valuable model to provide more comprehensive assessment of tumor in response to therapeutic strategies. Here, we applied chitosan-hyaluronan (HA) membranes as a platform to promote three-dimensional (3D) tumor spheroid formation. The biological features of tumor spheroids of human non-small cell lung cancer (NSCLC) cells on chitosan-HA membranes were compared to those of 2D cultured cells in vitro. The cells in tumor spheroids cultured on chitosan-HA membranes showed higher levels of stem-like properties and epithelial-mesenchymal transition (EMT) markers, such as NANOG, SOX2, CD44, CD133, N-cadherin, and vimentin, than 2D cultured cells. Moreover, they exhibited enhanced invasive activities and multidrug resistance by the upregulation of MMP2, MMP9, BCRC5, BCL2, MDR1, and ABCG2 as compared with 2D cultured cells. The grafting densities of HA affected the tumor sphere size and mRNA levels of genes on the substrates. These evidences suggest that chitosan-HA membranes may offer a simple and valuable biomaterial platform for rapid generation of tumor spheroids in vitro as well as for further applications in cancer stem cell research and cancer drug screening. Copyright © 2014 Elsevier Ltd. All rights reserved.

Anti-fouling and high water permeable forward osmosis membrane fabricated via layer by layer assembly of chitosan/graphene oxide

Science.gov (United States)

Salehi, Hasan; Rastgar, Masoud; Shakeri, Alireza

2017-08-01

To date, forward osmosis (FO) has received considerable attention due to its potential application in seawater desalination. FO does not require external hydraulic pressure and consequently is believed to have a low fouling propensity. Despite the numerous privileges of FO process, a major challenge ahead for its development is the lack of high performance membranes. In this study, we fabricated a novel highly-efficient FO membrane using layer-by-layer (LbL) assembly of positive chitosan (CS) and negative graphene oxide (GO) nanosheets via electrostatic interaction on a porous support layer. The support layer was prepared by blending hydrophilic sulfonated polyethersulfone (SPES) into polyethersulfone (PES) matrix using wet phase inversion process. Various characterization techniques were used to confirm successful fabrication of LbL membrane. The number of layers formed on the SPES-PES support layer was easily adjusted by repeating the CS and GO deposition cycles. Thin film composite (TFC) membrane was also prepared by the same SPES-PES support layer and polyamide (PA) active layer to compare membranes performances. The water permeability and salt rejection of the fabricated membranes were obtained by two kinds of draw solutions (including Na2SO4 and sucrose) under two different membrane orientations. The results showed that membrane coated by a CS/GO bilayers had water flux of 2-4 orders of magnitude higher than the TFC one. By increasing the number of CS/GO bilayers, the selectivity of the LbL membrane was improved. The novel fabricated LbL membrane showed better fouling resistance than the TFC one in the feed solution containing 200 ppm of sodium alginate as a foulant model.

Optimization of Chitosan Drying Temperature on The Quality and Quantity of Edible Film

Science.gov (United States)

Sri Wahyuni, Endah; Arifan, Fahmi

2018-02-01

Edible film is a thin layer (biodegradable) used to coat food and can be eaten. In addition edible film serves as a vapor transfer inhibitor, inhibits gas exchange, prevents aroma loss, prevents fat transfer, improves physical characteristics, and as an additive carrier. Edible film made of cassava starch, glycerol and chitosan. Cassava starch is used as raw material because it contains 80% starch. Glycerol serves as a plasticizer and chitosan serves to form films and membranes well. The purpose of this research is to know the characteristic test of edible film by using ANOVA analysis, where the variable of drying of the oven is temperature (70°C, 80°C, 90°C) and time for 3 hours and variables change chitosan (2 gr, 3 gr, 4 gr). The result of this research was obtained the most optimum for water content and water resistance in temperature variable 80 °C and chitosan 4 gr. The best edible films and bubbles on temperature variables are 80 °C and chitosan 4 gr.

Method of producing a carbon coated ceramic membrane and associated product

Science.gov (United States)

Liu, Paul K. T.; Gallaher, George R.; Wu, Jeffrey C. S.

1993-01-01

A method of producing a carbon coated ceramic membrane including passing a selected hydrocarbon vapor through a ceramic membrane and controlling ceramic membrane exposure temperature and ceramic membrane exposure time. The method produces a carbon coated ceramic membrane of reduced pore size and modified surface properties having increased chemical, thermal and hydrothermal stability over an uncoated ceramic membrane.

Chitosan coatings crosslinked with genipin for corrosion protection of AZ31 magnesium alloy sheets.

Science.gov (United States)

de Y Pozzo, Ludmila; da Conceição, Thiago F; Spinelli, Almir; Scharnagl, Nico; Pires, Alfredo T N

2018-02-01

In this study, coatings of chitosan crosslinked with genipin were prepared on sheets of AZ31 magnesium alloy and their corrosion protection properties were characterized by means of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The coatings were also characterized by means of FTIR and XPS. It was observed that the crosslinking process decreases the corrosion current and shifts the corrosion potential of the alloy to less negative values. The EIS analysis demonstrated that the crosslinking process increases the maximum impedance after short and long exposure times. The superior performance of the crosslinked coatings is related to a lower degree of swelling, as observed in the swelling tests carried out on free-standing films. Copyright © 2017 Elsevier Ltd. All rights reserved.

Preparation, characterization, and in vitro and in vivo investigation of chitosan-coated poly (d,l-lactide-co-glycolide) nanoparticles for intestinal delivery of exendin-4

Science.gov (United States)

Wang, Mengshu; Zhang, Yong; Feng, Jiao; Gu, Tiejun; Dong, Qingguang; Yang, Xu; Sun, Yanan; Wu, Yongge; Chen, Yan; Kong, Wei

2013-01-01

Background Exendin-4 is an incretin mimetic agent approved for type 2 diabetes treatment. However, the required frequent injections restrict its clinical application. Here, the potential use of chitosan-coated poly (d,l-lactide-co-glycolide) (CS-PLGA) nanoparticles was investigated for intestinal delivery of exendin-4. Methods and results Nanoparticles were prepared using a modified water–oil–water (w/o/w) emulsion solvent-evaporation method, followed by coating with chitosan. The physical properties, particle size, and cell toxicity of the nanoparticles were examined. The cellular uptake mechanism and transmembrane permeability were performed in Madin-Darby canine kidney-cell monolayers. Furthermore, in vivo intraduodenal administration of exendin-4-loaded nanoparticles was carried out in rats. The PLGA nanoparticle coating with chitosan led to a significant change in zeta potential, from negative to positive, accompanied by an increase in particle size of ~30 nm. Increases in both the molecular weight and degree of deacetylation of chitosan resulted in an observable increase in zeta potential but no apparent change in the particle size of ~300 nm. Both unmodified PLGA and chitosan-coated nanoparticles showed only slight cytotoxicity. Use of different temperatures and energy depletion suggested that the cellular uptake of both types of nanoparticles was energy-dependent. Further investigation revealed that the uptake of PLGA nanoparticles occurred via caveolin-mediated endocytosis and that of CS-PLGA nanoparticles involved both macropinocytosis and clathrin-mediated endocytosis, as evidenced by using endocytic inhibitors. However, under all conditions, CS-PLGA nanoparticles showed a greater potential to be transported into cells, as shown by flow cytometry and confocal microscopy. Transmembrane permeability analysis showed that unmodified and modified PLGA nanoparticles could improve the transport of exendin-4 by up to 8.9- and 16.5-fold, respectively

Application of radiation degraded CM-chitosan for preservation of fresh fruits

International Nuclear Information System (INIS)

Quynh, Tran Minh; Hien, Nuguyen Quoc; Yoshii, Fumio; Nagasawa, Naotsugu; Kume, Tamikazu

2003-01-01

CM-chitosan was irradiated with various doses in powder state and solution using Co 60 gamma source. The changes of viscosity in solution as well as molecular weight were also measured. The molecular weight reduced with increasing of radiation dose. The antimicrobial activity of CM-chitosan and irradiated CM-chitosan in solution against E.coli was investigated. In this studies, the sensitivity of E.coli depended on the concentration of CM-chitosan supplemented into medium and the antimicrobial activity of irradiated CM-chitosan was found to increase with radiation dose and reached to maximum with dose of 100 kGy. The 2% aqueous solutions prepared from CM-chitosan and 100 kGy irradiated CM-chitosan as mentioned above were applied for apple preservation. All coating fruits have significantly reduced the weight loss, spoilage ratio compared with control. Chemical and sensory quality of coated fruits were evaluated and compared, the best results were achieved with fruit coated using irradiated CM-chitosan. (author)

Chitosan/CNTs green nanocomposite membrane: synthesis, swelling and polyaromatic hydrocarbons removal.

Science.gov (United States)

Bibi, Saira; Yasin, Tariq; Hassan, Safia; Riaz, Muhammad; Nawaz, Mohsan

2015-01-01

Carbon nanotubes (CNTs) were irradiated in air at 100 kGy under gamma radiations. The Raman spectroscopy of γ-treated CNTs showed distinctive changes in the absorption bands. The CNTs were mixed with blend of chitosan (Cs)/poly (vinyl alcohol) (PVA) and crosslinked with silane. The chemical reactions between the components affected the position and intensities of the infrared bands. Scanning electron micrograph of Cs/CNTs nanocomposite membrane showed the homogeneous dispersion of CNTs in the polymer matrix. The addition of CNTs lowered its swelling in water. Naphthalene (NAPH) was selected as a model compound and its removal was studied using HPLC technique. This membrane showed fast uptake of NAPH and 87% was removed from water within 30 min. The NAPH loaded membrane showed strong chemical interactions and cannot be desorbed. The fast uptake of PAHs and the green nature of this membrane made them suitable candidates for clean-up purposes. Copyright © 2014 Elsevier B.V. All rights reserved.

The structure of the COPII transport-vesicle coat assembled on membranes.

Science.gov (United States)

Zanetti, Giulia; Prinz, Simone; Daum, Sebastian; Meister, Annette; Schekman, Randy; Bacia, Kirsten; Briggs, John A G

2013-09-17

Coat protein complex II (COPII) mediates formation of the membrane vesicles that export newly synthesised proteins from the endoplasmic reticulum. The inner COPII proteins bind to cargo and membrane, linking them to the outer COPII components that form a cage around the vesicle. Regulated flexibility in coat architecture is essential for transport of a variety of differently sized cargoes, but structural data on the assembled coat has not been available. We have used cryo-electron tomography and subtomogram averaging to determine the structure of the complete, membrane-assembled COPII coat. We describe a novel arrangement of the outer coat and find that the inner coat can assemble into regular lattices. The data reveal how coat subunits interact with one another and with the membrane, suggesting how coordinated assembly of inner and outer coats can mediate and regulate packaging of vesicles ranging from small spheres to large tubular carriers. DOI:http://dx.doi.org/10.7554/eLife.00951.001.

Applying quality by design (QbD) concept for fabrication of chitosan coated nanoliposomes.

Science.gov (United States)

Pandey, Abhijeet P; Karande, Kiran P; Sonawane, Raju O; Deshmukh, Prashant K

2014-03-01

In the present investigation, a quality by design (QbD) strategy was successfully applied to the fabrication of chitosan-coated nanoliposomes (CH-NLPs) encapsulating a hydrophilic drug. The effects of the processing variables on the particle size, encapsulation efficiency (%EE) and coating efficiency (%CE) of CH-NLPs (prepared using a modified ethanol injection method) were investigated. The concentrations of lipid, cholesterol, drug and chitosan; stirring speed, sonication time; organic:aqueous phase ratio; and temperature were identified as the key factors after risk analysis for conducting a screening design study. A separate study was designed to investigate the robustness of the predicted design space. The particle size, %EE and %CE of the optimized CH-NLPs were 111.3 nm, 33.4% and 35.2%, respectively. The observed responses were in accordance with the predicted response, which confirms the suitability and robustness of the design space for CH-NLP formulation. In conclusion, optimization of the selected key variables will help minimize the problems related to size, %EE and %CE that are generally encountered when scaling up processes for NLP formulations. The robustness of the design space will help minimize both intra-batch and inter-batch variations, which are quite common in the pharmaceutical industry.

Chitosan nanoparticle-based neuronal membrane sealing and neuroprotection following acrolein-induced cell injury

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Shi Riyi

2010-01-01

Full Text Available Abstract Background The highly reactive aldehyde acrolein is a very potent endogenous toxin with a long half-life. Acrolein is produced within cells after insult, and is a central player in slow and progressive "secondary injury" cascades. Indeed, acrolein-biomolecule complexes formed by cross-linking with proteins and DNA are associated with a number of pathologies, especially central nervous system (CNS trauma and neurodegenerative diseases. Hydralazine is capable of inhibiting or reducing acrolein-induced damage. However, since hydralazine's principle activity is to reduce blood pressure as a common anti-hypertension drug, the possible problems encountered when applied to hypotensive trauma victims have led us to explore alternative approaches. This study aims to evaluate such an alternative - a chitosan nanoparticle-based therapeutic system. Results Hydralazine-loaded chitosan nanoparticles were prepared using different types of polyanions and characterized for particle size, morphology, zeta potential value, and the efficiency of hydralazine entrapment and release. Hydralazine-loaded chitosan nanoparticles ranged in size from 300 nm to 350 nm in diameter, and with a tunable, or adjustable, surface charge. Conclusions We evaluated the utility of chitosan nanoparticles with an in-vitro model of acrolein-mediated cell injury using PC -12 cells. The particles effectively, and statistically, reduced damage to membrane integrity, secondary oxidative stress, and lipid peroxidation. This study suggests that a chitosan nanoparticle-based therapy to interfere with "secondary" injury may be possible.

Surface and protein analyses of normal human cell attachment on PIII-modified chitosan membranes

International Nuclear Information System (INIS)

Saranwong, N.; Inthanon, K.; Wongkham, W.; Wanichapichart, P.; Suwannakachorn, D.; Yu, L.D.

2012-01-01

Surface of chitosan membrane was modified with argon (Ar) and nitrogen (N) plasma immersion ion implantation (PIII) for human skin fibroblasts F1544 cell attachment. The modified surfaces were characterized by Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM). Cell attachment patterns were evaluated by scanning electron microscopy (SEM). The enzyme-linked immunosorbent assay (ELISA) was used to quantify levels of focal adhesion kinase (FAK). The results showed that Ar PIII had an enhancement effect on the cell attachment while N-PIII had an inhibition effect. Filopodial analysis revealed more microfilament cytoplasmic spreading on the edge of cells attached on the Ar-treated membranes than N-treated membranes. Higher level FAK was found in Ar-treated membranes than that in N-treated membranes.

Chemical and biological assessment of Cd-polluted sediment for land use: The effect of stabilization using chitosan-coated zeolite.

Science.gov (United States)

Wen, Jia; Zeng, Guangming

2018-04-15

Disposal of dredged sediment contaminated with heavy metals on site or in landfills inevitably causes leaching of metals that generate new environmental problems. In this study, we investigated the effectiveness of stabilizing heavy metal Cd in sediment taken from Dongting Lake, China, using a chitosan-coated zeolite, and assessed the feasibility of reusing the stabilized sediment in river bank soil based on chemical and biological analyses. Results showed that the addition of chitosan-coated zeolite significantly reduced acid-exchangeable Cd by 8% in the dredged sediment and 7% in a sediment-soil mixture. Cadmium leachability was greatly reduced in the amended sediment or sediment-soil mixture. Toxicity bioassay using Eisenia fetida showed the mortality rate of worms reduced by 16% in sediment-soil mixture with a Cd concentration of 550 mg/kg and by 17% under a Cd concentration of 250 mg/kg, both with the addition of modified zeolite. Moreover, assimilation of Cd in the earthworms was decreased by a maximum of 36 mg/kg in the sediment-soil mixture with zeolite amendment. These results indicate that the reuse of Cd-contaminated sediment following chitosan-coated zeolite modification is a feasible option for treating the dredged sediment, and could thus benefit both aquatic and terrestrial systems. Copyright © 2018 Elsevier Ltd. All rights reserved.

Cytotoxicity study of novel water-soluble chitosan derivatives applied as membrane material of alginate microcapsules

NARCIS (Netherlands)

Sobol, Marcin; Bartkowiak, Artur; de Haan, Bart; de Vos, Paul

The majority of cell encapsulation systems applied so far are based on polyelectrolyte complexes of alginate and polyvalent metal cations. Although widely used, these systems suffer from the risk of disintegration. This can be partially solved by applying chitosan as additional outer membrane.

Novel chitosan/diclofenac coatings on medical grade stainless steel for hip replacement applications

Science.gov (United States)

Finšgar, Matjaž; Uzunalić, Amra Perva; Stergar, Janja; Gradišnik, Lidija; Maver, Uroš

2016-05-01

Corrosion resistance, biocompatibility, improved osteointegration, as well the prevention of inflammation and pain are the most desired characteristics of hip replacement implants. In this study we introduce a novel multi-layered coating on AISI 316LVM stainless steel that shows promise with regard to all mentioned characteristics. The coating is prepared from alternating layers of the biocompatible polysaccharide chitosan and the non-steroid anti-inflammatory drug (NSAID), diclofenac. Electrochemical methods were employed to characterize the corrosion behavior of coated and uncoated samples in physiological solution. It is shown that these coatings improve corrosion resistance. It was also found that these coatings release the incorporated drug in controlled, multi-mechanism manner. Adding additional layers on top of the as-prepared samples, has potential for further tailoring of the release profile and increasing the drug dose. Biocompatibility was proven on human-derived osteoblasts in several experiments. Only viable cells were found on the sample surface after incubation of the samples with the same cell line. This novel coating could prove important for prolongation of the application potential of steel-based hip replacements, which are these days often replaced by more expensive ceramic or other metal alloys.

Development of Novel ECTFE Coated PP Composite Hollow-Fiber Membranes

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Sergio Santoro

2016-09-01

Full Text Available In this work composite hollow-fibers were prepared by dip-coating of commercial polypropylene (PP with a thin layer of ethylene–chlorotrifluoroethylene copolymer (ECTFE. The employment of N-methyl pyrrolidone (NMP as solvent improved the polymer processability favoring dip-coating at lower temperature (135 °C. Scanning electron microscopy (SEM analyses showed that after dip-coating the PP support maintained its microstructure, whereas a thin coated layer of ECTFE on the external surface of the PP hollow-fiber was clearly distinguishable. Membrane characterization evidenced the effects of the concentration of ECTFE in the dope-solution and the time of dip-coating on the thickness of ECTFE layer and membrane properties (i.e., contact angle and pore size. ECTFE coating decreased the surface roughness reducing, as a consequence, the hydrophobicity of the membrane. Moreover, increasing the ECTFE concentration and dip-coating time enabled the preparation of a thicker layer of ECTFE with low and narrow pore size that negatively affected the water transport. On the basis of the superior chemical resistance of ECTFE, ECTFE/PP composite hollow fibers could be considered as very promising candidates to be employed in membrane processes involving harsh conditions.

Enzymatic degradation behavior and cytocompatibility of silk fibroin-starch-chitosan conjugate membranes

Energy Technology Data Exchange (ETDEWEB)

Baran, Erkan T., E-mail: erkantur@metu.edu.tr; Tuzlakoglu, Kadriye, E-mail: kadriye@dep.uminho.pt; Mano, Joao F., E-mail: jmano@dep.uminho.pt; Reis, Rui L., E-mail: rgreis@dep.uminho.pt

2012-08-01

The objective of this study was to investigate the influence of silk fibroin and oxidized starch conjugation on the enzymatic degradation behavior and the cytocompatability of chitosan based biomaterials. The tensile stress of conjugate membranes, which was at 50 Megapascal (MPa) for the lowest fibroin and starch composition (10 weight percent (wt.%)), was decreased significantly with the increased content of fibroin and starch. The weight loss of conjugates in {alpha}-amylase was more notable when the starch concentration was the highest at 30 wt.%. The conjugates were resistant to the degradation by protease and lysozyme except for the conjugates with the lowest starch concentration. After 10 days of cell culture, the proliferation of osteoblast-like cells (SaOS-2) was stimulated significantly by higher fibroin compositions and the DNA synthesis on the conjugate with the highest fibroin (30 wt.%) was about two times more compared to the native chitosan. The light microscopy and the image analysis results showed that the cell area and the lengths were decreased significantly with higher fibroin/chitosan ratio. The study proved that the conjugation of fibroin and starch with the chitosan based biomaterials by the use of non-toxic reductive alkylation crosslinking significantly improved the cytocompatibility and modulated the biodegradation, respectively. - Highlights: Black-Right-Pointing-Pointer Silk fibroin, starch and chitosan conjugates were prepared by reductive alkylation. Black-Right-Pointing-Pointer The enzymatic biodegradation and the cytocompatibility of conjugates were tested. Black-Right-Pointing-Pointer The conjugate with 30% starch composition was degraded by {alpha}-amylase significantly. Black-Right-Pointing-Pointer Higher starch composition in conjugates prevented protease and lysozyme degradation. Black-Right-Pointing-Pointer Fibroin incorporation effectively increased the cell proliferation of conjugates.

Effectiveness of Postharvest Treatment with Chitosan to Control Citrus Green Mold

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Mohamed El Guilli

2016-03-01

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

Growth of apatite on chitosan-multiwall carbon nanotube composite membranes

Energy Technology Data Exchange (ETDEWEB)

Yang Jun; Yao Zhiwen [State Key Laboratory of Oral Diseases, West China College of Stomatology, Sichuan University, No 14, 3rd Section South People' s Road, Chengdu 610041 (China); Tang Changyu [Department of Polymer Science and Materials, Sichuan University (China); Darvell, B.W. [Dental Materials Science, Faculty of Dentistry, University of Hong Kong (Hong Kong); Zhang Hualin; Pan Lingzhan; Liu Jingsong [State Key Laboratory of Oral Diseases, West China College of Stomatology, Sichuan University, No 14, 3rd Section South People' s Road, Chengdu 610041 (China); Chen Zhiqing, E-mail: yangj0710@gmail.com [State Key Laboratory of Oral Diseases, West China College of Stomatology, Sichuan University, No 14, 3rd Section South People' s Road, Chengdu 610041 (China)

2009-07-30

Bioactive membranes for guided tissue regeneration would be of value for periodontal therapy. Chitosan-multiwall carbon nanotube (CS-MWNT) composites were treated to deposit nanoscopic apatite for MWNT proportions of 0-4 mass%. Fourier-transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis, and X-ray diffraction were used for characterization. Apatite was formed on the CS-MWNT composites at low MWNT concentrations, but the dispersion of the MWNT affects the crystallite size and the Ca/P molar ratio of the composite. The smallest crystallite size was 9 nm at 1 mass% MWNT.

2-Mercaptobenzothiazole doped chitosan/11-alkanethiolate acid composite coating: Dual function for copper protection

International Nuclear Information System (INIS)

Bao Qi; Zhang Dun; Wan Yi

2011-01-01

Chitosan (CS) hydrogel loaded with the well-known corrosion inhibitor 2-mercaptobenzothiazole (MBT) has been introduced into a composite coating to improve copper protection. This composite coating, which has both anticorrosion and antibacterial properties, was fabricated onto the surface of copper by combining a simple self-assembled monolayer technique with a sol-gel method. The anti-corrosion ability of the coating in 3.5 wt.% NaCl solution was investigated by electrochemical methods including potentiodynamic polarization and electrochemical impedance spectroscopy. The protection efficiency of the coating is 97.70%, calculated on the basis of the corrosion current density. The stability and integrity of the composite coating were evaluated by field emission scanning electron microscopy (FESEM) and energy dispersive spectrometry (EDS). The FESEM and EDS results suggest that the composite coating endows the copper substrate with antibacterial properties, as untreated bare copper underwent microbiologically influenced corrosion in the presence of sulphate reducing bacteria (SRB). This antibacterial feature was further confirmed by the SRB culture method. In a 3.5% NaCl solution and highly corrosive SRB culture media, the as-prepared CS based composite coating gave corrosion protection by exhibiting better barrier effects against the attack of aggressive environments.

Effect of chitosan and alginate based coatings enriched with pomegranate peel extract to extend the postharvest quality of guava (Psidium guajava L.).

Science.gov (United States)

Nair, M Sneha; Saxena, Alok; Kaur, Charanjit

2018-02-01

The influence of chitosan (1% w/v) and alginate (2% w/v) coatings in combination with pomegranate peel extract (PPE; 1% w/v) on quality of guavas (cv Allahabad safeda) were studied. Restricted changes were recorded in respiration rate, ripening index, and instrumental colour values in case of the coated samples as compared to the control for 20days at 10°C. Samples coated with chitosan enriched with PPE (CHE) proved to be the most effective treatment in maintaining the overall fruit quality. Ascorbic acid, total phenolics, total flavonoids contents and antioxidant activity were recorded with restricted losses of 29%, 8%, 12%, 12% (DPPH) and 9% (FRAP), respectively for CHE samples at the end of storage. A higher degree of correlation (r>0.918) was established between various phytochemicals and AOA. PPE enriched coatings was proved efficient in maintaining the quality of guavas during 20days of low temperature storage. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effect of layer-by-layer chitosan-hyaluronic acid coating on graft-to-bone healing of a poly(ethylene terephthalate) artificial ligament.

Science.gov (United States)

Li, Hong; Ge, Yunsheng; Zhang, Pengyun; Wu, Lingxiang; Chen, Shiyi

2012-01-01

Surface coating with an organic layer-by-layer self-assembled template of chitosan and hyaluronic acid on a poly(ethylene terephthalate) (PET) artificial ligament was designed for the promotion and enhancement of graft-to-bone healing after artificial ligament implantation in a bone tunnel. The results of in vitro culturing of MC3T3-E1 mouse osteoblastic cells supported the hypothesis that the layer-by-layer coating of chitosan and hyaluronic acid could promote the cell compatibility of grafts and could promote osteoblast proliferation. A rabbit extra-articular tendon-to-bone healing model was used to evaluate the effect of this kind of surface-modified stainless artificial ligament in vivo. The final results proved that this organic compound coating could significantly promote and enhance new bone formation at the graft-bone interface histologically and, correspondingly, the experimental group with coating had significantly higher biomechanical properties compared with controls at 8 weeks (P < 0.05).

Preparation, characterization, and in vitro and in vivo investigation of chitosan-coated poly (d,l-lactide-co-glycolide nanoparticles for intestinal delivery of exendin-4

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Wang M

2013-03-01

Full Text Available Mengshu Wang,1* Yong Zhang,1* Jiao Feng,1 Tiejun Gu,1 Qingguang Dong,1 Xu Yang,2 Yanan Sun,1 Yongge Wu,1 Yan Chen,1 Wei Kong1 1National Engineering Laboratory for AIDS Vaccine, College of Life Science, Jilin University, Changchun, People’s Republic of China; 2BCHT Biopharm Co, Ltd, Changchun, People’s Republic of China*These authors contributed equally to this workBackground: Exendin-4 is an incretin mimetic agent approved for type 2 diabetes treatment. However, the required frequent injections restrict its clinical application. Here, the potential use of chitosan-coated poly (d,l-lactide-co-glycolide (CS-PLGA nanoparticles was investigated for intestinal delivery of exendin-4.Methods and results: Nanoparticles were prepared using a modified water–oil–water (w/o/w emulsion solvent-evaporation method, followed by coating with chitosan. The physical properties, particle size, and cell toxicity of the nanoparticles were examined. The cellular uptake mechanism and transmembrane permeability were performed in Madin-Darby canine kidney-cell monolayers. Furthermore, in vivo intraduodenal administration of exendin-4-loaded nanoparticles was carried out in rats. The PLGA nanoparticle coating with chitosan led to a significant change in zeta potential, from negative to positive, accompanied by an increase in particle size of ~30 nm. Increases in both the molecular weight and degree of deacetylation of chitosan resulted in an observable increase in zeta potential but no apparent change in the particle size of ~300 nm. Both unmodified PLGA and chitosan-coated nanoparticles showed only slight cytotoxicity. Use of different temperatures and energy depletion suggested that the cellular uptake of both types of nanoparticles was energy-dependent. Further investigation revealed that the uptake of PLGA nanoparticles occurred via caveolin-mediated endocytosis and that of CS-PLGA nanoparticles involved both macropinocytosis and clathrin-mediated endocytosis

Silver-loaded chitosan coating as an integrated approach to face titanium implant-associated infections: analytical characterization and biological activity.

Science.gov (United States)

Cometa, Stefania; Bonifacio, Maria A; Baruzzi, Federico; de Candia, Silvia; Giangregorio, Maria M; Giannossa, Lorena C; Dicarlo, Manuela; Mattioli-Belmonte, Monica; Sabbatini, Luigia; De Giglio, Elvira

2017-12-01

The present work focuses on the idea to prevent and/or inhibit the colonization of implant surfaces by microbial pathogens responsible for post-operative infections, adjusting antimicrobial properties of the implant surface prior to its insertion. An antibacterial coating based on chitosan and silver was developed by electrodeposition techniques on poly(acrylic acid)-coated titanium substrates. When a silver salt was added during the chitosan deposition step, a stable and scalable silver incorporation was achieved. The physico-chemical composition of the coating was studied by X-ray photoelectron spectroscopy (XPS), while atomic force microscopy in intermittent contact mode (ICAFM) was used to explore the coating morphology. The amount of silver released from the coating up to 21 days was evaluated by inductively coupled plasma mass spectrometry (ICP-MS). The capability of the proposed coating to interact in vitro with the biological environment in terms of compatibility and antibacterial properties was assessed using MG-63 osteoblast-like cell line and S. aureus and P. aeruginosa strains, respectively. These studies revealed that a coating showing a silver surface atomic percentage equal to 0.3% can be effectively used as antibacterial system, while providing good viability of osteoblast-like cells after 7 days. The antibacterial effectiveness of the prepared coating is mainly driven by a contact killing mechanism, although the low concentration of silver released (below 0.1 ppm up to 21 days) is enough to inhibit bacterial growth, advantaging MG-63 cells in the race for the surface.

Preparation and Characterization of Facilitated Transport Membranes Composed of Chitosan-Styrene and Chitosan-Acrylonitrile Copolymers Modified by Methylimidazolium Based Ionic Liquids for CO2 Separation from CH4 and N2

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Ksenia V. Otvagina

2016-06-01

Full Text Available CO2 separation was found to be facilitated by transport membranes based on novel chitosan (CS–poly(styrene (PS and chitosan (CS–poly(acrylonitrile (PAN copolymer matrices doped with methylimidazolium based ionic liquids: [bmim][BF4], [bmim][PF6], and [bmim][Tf2N] (IL. CS plays the role of biodegradable film former and selectivity promoter. Copolymers were prepared implementing the latest achievements in radical copolymerization with chosen monomers, which enabled the achievement of outstanding mechanical strength values for the CS-based membranes (75–104 MPa for CS-PAN and 69–75 MPa for CS-PS. Ionic liquid (IL doping affected the surface and mechanical properties of the membranes as well as the gas separation properties. The highest CO2 permeability 400 Barrers belongs to CS-b-PS/[bmim][BF4]. The highest selectivity α (CO2/N2 = 15.5 was achieved for CS-b-PAN/[bmim][BF4]. The operational temperature of the membranes is under 220 °C.

Chemical coupling of thiolated chitosan to preformed liposomes improves mucoadhesive properties

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Gradauer K

2012-05-01

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

Determination of physical properties for β-TCP + chitosan biomaterial obtained on metallic 316L substrates

International Nuclear Information System (INIS)

Mina, A.; Castaño, A.; Caicedo, J.C.; Caicedo, H.H.; Aguilar, Y.

2015-01-01

Material surface modification, particularly the deposition of special coatings on the surface of surgical implants, is extensively used in bone tissue engineering applications. β-Tricalcium phosphate/Chitosan (β-TCP/Ch) coatings were deposited on 316L stainless steel (316L SS) substrates by a cathodic electro-deposition technique at different coating compositions. The crystal lattice arrangements were analyzed by X-Ray diffraction (XRD), and the results indicated that the crystallographic structure of β-TCP was affected by the inclusion of the chitosan content. The changes in the surface morphology as a function of increasing chitosan in the coatings via scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed that root-mean square values of the β-TCP/Ch coatings decreased by further increasing chitosan percentage. The elastic–plastic characteristics of the coatings were determined by conducting nanoindentation test, indicating that increase of chitosan percentage is directly related to increase of hardness and elastic modulus of the β-TCP/Ch coatings. Tribological characterization was performed by scratch test and pin-on-disk test to analyze the changes in the surface wear of β-TCP/Ch coatings. Finally, the results indicated an improvement in the mechanical and tribological properties of the β-TCP/Ch coatings as a function of increasing of the chitosan percentage. This new class of coatings, comprising the bioactive components, is expected not only to enhance the bioactivity and biocompatibility, but also to protect the surface of metallic implants against wear and corrosion. - Highlights: • Superficial phenomenon that occurs in tribological surface of β-tricalcium phosphate-chitosan coatings. • Improvement on surface mechanical properties of ceramic-polymeric and response to surface tribological damage. • β-tricalcium phosphate-chitosan coatings that offer highest performance in the biomedical devices

Determination of physical properties for β-TCP + chitosan biomaterial obtained on metallic 316L substrates

Energy Technology Data Exchange (ETDEWEB)

Mina, A. [Tribology, Powder Metallurgy and Processing of Solid Recycled Research Group, Universidad del Valle, Cali (Colombia); Tecno-Academia ASTIN SENA Reginal Valle (Colombia); Castaño, A. [Tribology, Powder Metallurgy and Processing of Solid Recycled Research Group, Universidad del Valle, Cali (Colombia); Caicedo, J.C., E-mail: julio.cesar.caicedo@correo.univalle.edu.co [Tribology, Powder Metallurgy and Processing of Solid Recycled Research Group, Universidad del Valle, Cali (Colombia); Caicedo, H.H. [Biologics Research, Biotechnology Center of Excellence, Janssen R& D, LLC, Pharmaceutical Companies of Johnson & Johnson, Spring House, PA 19477 (United States); National Biotechnology & Pharmaceutical Association, Chicago, IL 60606 (United States); Aguilar, Y. [Tribology, Powder Metallurgy and Processing of Solid Recycled Research Group, Universidad del Valle, Cali (Colombia)

2015-06-15

Material surface modification, particularly the deposition of special coatings on the surface of surgical implants, is extensively used in bone tissue engineering applications. β-Tricalcium phosphate/Chitosan (β-TCP/Ch) coatings were deposited on 316L stainless steel (316L SS) substrates by a cathodic electro-deposition technique at different coating compositions. The crystal lattice arrangements were analyzed by X-Ray diffraction (XRD), and the results indicated that the crystallographic structure of β-TCP was affected by the inclusion of the chitosan content. The changes in the surface morphology as a function of increasing chitosan in the coatings via scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed that root-mean square values of the β-TCP/Ch coatings decreased by further increasing chitosan percentage. The elastic–plastic characteristics of the coatings were determined by conducting nanoindentation test, indicating that increase of chitosan percentage is directly related to increase of hardness and elastic modulus of the β-TCP/Ch coatings. Tribological characterization was performed by scratch test and pin-on-disk test to analyze the changes in the surface wear of β-TCP/Ch coatings. Finally, the results indicated an improvement in the mechanical and tribological properties of the β-TCP/Ch coatings as a function of increasing of the chitosan percentage. This new class of coatings, comprising the bioactive components, is expected not only to enhance the bioactivity and biocompatibility, but also to protect the surface of metallic implants against wear and corrosion. - Highlights: • Superficial phenomenon that occurs in tribological surface of β-tricalcium phosphate-chitosan coatings. • Improvement on surface mechanical properties of ceramic-polymeric and response to surface tribological damage. • β-tricalcium phosphate-chitosan coatings that offer highest performance in the biomedical devices.

Synthesis and characterization of the superparamagnetic iron oxide nanoparticles modified with cationic chitosan and coated with silica shell

Energy Technology Data Exchange (ETDEWEB)

Lewandowska-Łańcucka, Joanna, E-mail: lewandow@chemia.uj.edu.pl [Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow (Poland); Staszewska, Magdalena; Szuwarzyński, Michał; Kępczyński, Mariusz [Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow (Poland); Romek, Marek [Department of Cytology and Histology, Institute of Zoology, Jagiellonian University, Gronostajowa 9, 30-387 Krakow (Poland); Tokarz, Waldemar [Department of Solid State Physics, AGH University of Science and Technology, al. A. Mickiewicza 30, 30-059 Krakow (Poland); Szpak, Agnieszka; Kania, Gabriela; Nowakowska, Maria [Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow (Poland)

2014-02-15

Highlights: • The new, facile methodology for synthesis of silica covered SPIONs is proposed. • The SPIONs was modified with cationic chitosan and coated with silica shell. • Negatively charged, rounded in shape particles of ca. 330 nm were obtained. • The product exhibits the superparamagnetic properties. • The product properties imply its potential applications in biomedicine areas. -- Abstract: Novel method for synthesis of superparamagnetic iron oxide nanoparticles (SPION) modified with a cationic chitosan (CCh) and coated with a silica shell, SPION-CCh-SiO{sub 2} was developed. The process was carried out in two steps. In the first step the chitosan coated SPIONs were obtained by co-precipitation of Fe{sup 2+} and Fe{sup 3+} with ammonium hydroxide in aqueous solution of CCh. In the second one, the silica shell is formed on their surfaces. The formation of SPION-CCh-SiO{sub 2} was achieved by direct decomposition of tetraethoxysilane (TEOS) adsorbed on a surface of SPION-CCh dispersed in aqueous phase under sonication and mechanical stirring at room temperature. The chemical composition and physicochemical properties of the materials were determined using X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Dynamic Light Scattering (DLS) and zeta potential measurements. The morphology of the particles was evaluated by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). Magnetic properties were confirmed using Atomic Force Microscopy/Magnetic Force Microscopy (AFM/MFM) and magnetization measurements. The resulting products are negatively charged, rounded in shape and exhibit the superparamagnetic properties what implies their potential applications in engineering and biomedicine areas.

Synthesis and characterization of the superparamagnetic iron oxide nanoparticles modified with cationic chitosan and coated with silica shell

International Nuclear Information System (INIS)

Lewandowska-Łańcucka, Joanna; Staszewska, Magdalena; Szuwarzyński, Michał; Kępczyński, Mariusz; Romek, Marek; Tokarz, Waldemar; Szpak, Agnieszka; Kania, Gabriela; Nowakowska, Maria

2014-01-01

Highlights: • The new, facile methodology for synthesis of silica covered SPIONs is proposed. • The SPIONs was modified with cationic chitosan and coated with silica shell. • Negatively charged, rounded in shape particles of ca. 330 nm were obtained. • The product exhibits the superparamagnetic properties. • The product properties imply its potential applications in biomedicine areas. -- Abstract: Novel method for synthesis of superparamagnetic iron oxide nanoparticles (SPION) modified with a cationic chitosan (CCh) and coated with a silica shell, SPION-CCh-SiO 2 was developed. The process was carried out in two steps. In the first step the chitosan coated SPIONs were obtained by co-precipitation of Fe 2+ and Fe 3+ with ammonium hydroxide in aqueous solution of CCh. In the second one, the silica shell is formed on their surfaces. The formation of SPION-CCh-SiO 2 was achieved by direct decomposition of tetraethoxysilane (TEOS) adsorbed on a surface of SPION-CCh dispersed in aqueous phase under sonication and mechanical stirring at room temperature. The chemical composition and physicochemical properties of the materials were determined using X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Dynamic Light Scattering (DLS) and zeta potential measurements. The morphology of the particles was evaluated by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). Magnetic properties were confirmed using Atomic Force Microscopy/Magnetic Force Microscopy (AFM/MFM) and magnetization measurements. The resulting products are negatively charged, rounded in shape and exhibit the superparamagnetic properties what implies their potential applications in engineering and biomedicine areas

Effect of chitosan coating and bamboo FSC (fruit storage chamber) to expand banana shelf life

Science.gov (United States)

Pratiwi, Aksarani'Sa; Dwivany, Fenny M.; Larasati, Dwinita; Islamia, Hana Cahya; Martien, Ronny

2015-09-01

Chitosan has been widely used as fruit preserver and proven to extend the shelf life of many fruits, such as banana. However, banana producers and many industries in Indonesia still facing storage problems which may lead to mechanical damage of the fruits and ripening acceleration. Therefore, we have designed food storage chamber (FSC) based on bamboo material. Bamboo was selected because of material abundance in Indonesia, economically effective, and not causing an autocatalytic reaction to the ethylene gas produced by the banana. In this research, Cavendish banana that has reached the maturity level of mature green were coated with 1% chitosan and placed inside the FSC. As control treatments, uncoated banana was also placed inside the FSC as well as uncoated banana that were placed at open space. All of the treatments were placed at 25°C temperature and observed for 9 days. Water produced by respiration was reduced by the addition of charcoal inside a fabric pouch. The result showed that treatment using FSC and chitosan can delay ripening process.

Pore size and LbL chitosan coating influence mesenchymal stem cell in vitro fibrosis and biomineralization in 3D porous poly(epsilon-caprolactone) scaffolds.

Science.gov (United States)

Mehr, Nima Ghavidel; Li, Xian; Chen, Gaoping; Favis, Basil D; Hoemann, Caroline D

2015-07-01

Poly(epsilon-caprolactone) (PCL) is a hydrophobic bioplastic under development for bone tissue engineering applications. Limited information is available on the role of internal geometry and cell-surface attachment on osseous integration potential. We tested the hypothesis that human bone marrow mesenchymal stem cells (MSCs) deposit more mineral inside porous 3D PCL scaffolds with fully interconnected 84 or 141 µm pores, when the surfaces are coated with chitosan via Layer-by-Layer (LbL)-deposited polyelectrolytes. Freshly trypsinized MSCs were seeded on PCL 3D cylinders using a novel static cold seeding method in 2% serum to optimally populate all depths of the scaffold discs, followed by 10 days of culture in proliferation medium and 21 additional days in osteogenic medium. MSCs were observed by SEM and histology to spread faster and to proliferate more on chitosan-coated pore surfaces. Most pores, with or without chitosan, became filled by collagen networks sparsely populated with fibroblast-like cells. After 21 days of culture in osteogenic medium, sporadic matrix mineralization was detected histologically and by micro-CT in highly cellular surface layers that enveloped all scaffolds and in cell aggregates in 141 µm pores near the edges. LbL-chitosan promoted punctate mineral deposition on the surfaces of 84 µm pores (p chitosan coatings are sufficient to promote MSC attachment to PCL but only enhance mineral formation in 84 µm pores, suggesting a potential inhibitory role for MSC-derived fibroblasts in osteoblast terminal differentiation. © 2014 Wiley Periodicals, Inc.

Self-healing Anticorrosion Coatings for Gas Pipelines and Storage Tanks

Energy Technology Data Exchange (ETDEWEB)

Luckachan, G. E.; Mittal, V. [The Petroleum Institute, Abudhabi (United Arab Emirates)

2016-10-15

In the present study, chitosan based self-healing anticorrosion coatings were prepared by layer by layer (lbl) addition of chitosan (Ch) and polyvinyl butyral (PVB) on mild carbon steel substrate. Chitosan coatings exhibited enhanced coating stability and corrosion resistance in aggressive environments by the application of a PVB top layer. Chitosan layer in the lbl coatings have been modified by using glutaraldehyde (Glu) and silica (SiO{sub 2}). Performance of different coatings was tested using electrochemical impedance spectroscopy and immersion test. The best anticorrosion performance was observed in case of 10 % Ch{sub S}iO{sub 2P}VB coatings, which withstand immersion test over 25 days in 0.5 M salt solution without visible corrosion. 10 % Ch{sub S}iO{sub 2} coatings without the PVB top layer didn't last more than 3days. Application of PVB top layer sealed the defects in the chitosan pre-layer and improved its hydrophobic nature as well. Raman spectra and SEM of steel surfaces after corrosion study and removal of PVB{sub C}h/Glu{sub P}VB coatings showed a passive layer of iron oxide, attributing to the self-healing nature of these coatings. Conducting particle like graphene reinforcement of chitosan in the lbl coatings enhanced corrosion resistance of chitosan coatings.

A mechanical impact of coatings on membranes

DEFF Research Database (Denmark)

Hansen, Michael Søren; Reus, Roger De; Eriksen, Gert Friis

2001-01-01

The mechanical impact of coatings containing residual stress on membranes is investigated. Closed-form formulas describing this impact are presented and verified using both finite element modeling and physical experiments. Theory and experiments are in good agreement. Thus, a simple tool for design...... of coated pressure sensors is provided....

Novel Fouling-Reducing Coatings for Ultrafiltration, Nanofiltration, and Reverse Osmosis Membranes

Energy Technology Data Exchange (ETDEWEB)

Benny Freeman

2008-08-31

Polymeric membranes could potentially be the most flexible and viable long-term strategy for treatment of produced water from oil and gas production. However, widespread use of membranes, including reverse osmosis (RO) membranes, for produced water purification is hindered due to fouling caused by the impurities present in the water. Fouling of RO membranes is likely caused by surface properties including roughness, hydrophilicity, and charge, so surface modification is the most widely considered approach to improve the fouling properties of current RO membranes. This project focuses on two main approaches to surface modification: coating and grafting. Hydrophilic coating and grafting materials based on poly(ethylene glycol) (PEG) are applied to commercial RO membranes manufactured by Dow FilmTec and GE. Crossflow filtration experiments are used to determine the fouling resistance of modified membranes, and compare their performance to that of unmodified commercial RO membranes. Grafting and coating are shown to be two alternative methods of producing modified membranes with improved fouling resistance.

Reverse osmosis desalination of chitosan cross-linked graphene oxide/titania hybrid lamellar membranes.

Science.gov (United States)

Deng, Hui; Sun, Penzhan; Zhang, Yingjiu; Zhu, Hongwei

2016-07-08

With excellent mass transport properties, graphene oxide (GO)-based lamellar membranes are believed to have great potential in water desalination. In order to quantify whether GO-based membranes are indeed suitable for reverse osmosis (RO) desalination, three sub-micrometer thick GO-based lamellar membranes: GO-only, reduced GO (RGO)/titania (TO) nanosheets and RGO/TO/chitosan (CTS) are prepared, and their RO desalination performances are evaluated in a home-made RO test apparatus. The photoreduction of GO by TO improves the salt rejection, which increases slowly with the membrane thickness. The RGO/TO/CTS hybrid membranes exhibit higher rejection rates of only about 30% (greater than threefold improvement compared with a GO-only membrane) which is still inferior compared to other commercial RO membranes. The low rejection rates mainly arise from the pressure-induced weakening of the ion-GO interlayer interactions. Despite the advantages of simple, low-cost preparation, high permeability and selectivity of GO-based lamellar membranes, as the current desalination performances are not high enough to afford practical application, there still remains a great challenge to realize high performance separation membranes for water desalination applications.

Synthesis and characterization of ionic liquid (EMImBF{sub 4})/Li{sup +} - chitosan membranes for ion battery

Energy Technology Data Exchange (ETDEWEB)

Pasaribu, Marvin H., E-mail: marvin-shady88@yahoo.com; Arcana, I Made, E-mail: arcana@chem.itb.ac.id; Wahyuningrum, Deana, E-mail: deana@chem.itb.ac.id [Department of Chemistry, Faculty of Mathematics and Natural Sciences, InstitutTeknologi Bandung, Jl. Ganesha No. 10, Bandung 40132 (Indonesia)

2015-09-30

Lithium ion battery has been currently developed and produced because it has a longer life time, high energycapacity, and the efficient use of lithium ion battery that is suitable for storing electrical energy. However, this battery has some drawbacks such as use liquid electrolytes that are prone to leakage and flammability during the battery charging process in high temperature. In this study, an ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF4) containing Li{sup +} ions was synthesized and combined with chitosan polymer host as a polymer electrolyte membrane for lithium-ion batteries to solve this problems. This ionic liquid was obtained from the anion metathesis reaction between EMImBr and LiBF4 salt, while EMImBr was synthesized from the reaction between 1-methylimidazole and ethyl bromide utilizing Microwave Assisted Organic Synthesis (MAOS) method. The ionic liquid obtained was characterized by microstructure analysis with using NMR and FTIR spectroscopy. The polymer electrolyte membrane was characterized by analysis functional groups (FTIR), ionic conductivity (EIS), and surface morphology (SEM). The analysis results of ion conductivity by the EIS method showed the increase the ionic conductivity value of membranes from 1.30 × 10{sup −2} S cm{sup −1} for chitosan to 1.30 × 10{sup −2} S cm{sup −1} for chitosan with EMImBF4/Li{sup +}, and this result was supported by analysis the surface morphology (SEM)

Colour-Value Based Method for Polydopamine Coating-Stability Characterization on Polyethersulfone Membranes.

Science.gov (United States)

Bucher, Thomas; Clodt, Juliana I; Grabowski, Andrej; Hein, Martin; Filiz, Volkan

2017-12-16

Porous polyethersulfone membranes as used in oenology were investigated in order to evaluate temperature-dependent permeances in a temperature range from 10 to 35 °C. A temperature correction factor was determined for this type of membrane to get accurate and comparable results for further developments. Moreover, the membranes were modified with a bio-inspired polydopamine coating in order to reduce fouling. The performance of the membranes could be increased with respect to permeance and flux recovery under cross-flow conditions. In order to test the applicability and stability of the coating layer, they were treated with basic and acidic cleaning agents as used in industry for fouled membranes. The chemical stability of the coating layer was studied under basic and acidic conditions, by systematic observation of the colour change of the coated membranes over treatment time.

Preparation and characterisation of Punica granatum pericarp aqueous extract loaded chitosan-collagen-starch membrane: role in wound healing process.

Science.gov (United States)

Amal, B; Veena, B; Jayachandran, V P; Shilpa, Joy

2015-05-01

Engineered scaffolds made from natural biomaterials are crucial elements in tissue engineering strategies. In this study, biological scaffold like chitosan-collagen-starch membrane (CCSM) loaded with the antibacterial agent, Punica granatum pericarp aqueous extract was explored for enhanced regeneration of epithelial tissue during wound healing. Collagen was extracted from Rachycentron canadum fish skin. Membranous scaffold was prepared by mixing collagen, starch and chitosan in a fixed proportion, loaded with aqueous extract of P. granatum and its anti-pseudomonal activity was studied. Morphological characterization by SEM and mechanical property like tensile strength of the membrane were studied. Excision wound of 2 cm(2) size was induced in Guinea pig and the effect of P. granatum extract loaded CCSM in wound healing was studied. The SEM image showed deep pores in the membrane and also possessed good tensile strength. Wound surface area was reduced prominently in the experimental group with P. granatum extract loaded CCSM when compared to the group with unloaded membrane and the one with no membrane. Punica granatum extract loaded CCSM has antipseudomonal property and supported enhanced epithelial cell proliferation without leaving a scar after wound healing. This has significant therapeutic application in membranous scaffold mediated skin repair and regeneration.

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.

Enhanced performance of PVDF nanocomposite membrane by nanofiber coating: A membrane for sustainable desalination through MD.

Science.gov (United States)

Efome, Johnson E; Rana, Dipak; Matsuura, Takeshi; Lan, Christopher Q

2016-02-01

Membrane distillation (MD) is a promising separation technique capable of being used in the desalination of marine and brackish water. Poly(vinylidene fluoride) (PVDF) flat sheet nano-composite membranes were surface modified by coating with electro-spun PVDF nano-fibres to increase the surface hydrophobicity. For this purpose, the nano-composite membrane containing 7 wt.% superhydrophobic SiO2 nano-particles, which showed the highest flux in our previous work, was first subjected to pore size augmentation by increasing the concentration of the pore forming agent (Di-ionized water). Then, the prepared flat sheet membranes were subjected to nanofibres coating by electro-spinning. The uncoated and coated composite fabricated membranes were characterized using contact angle, liquid entry pressure of water, and scanning electron microscopy. The membranes were further tested for 6 h desalination by direct contact membrane distillation (DCMD) and vacuum membrane distillation (VMD), with a 3.5 wt.% synthetic NaClaq as the feed. In DCMD the feed liquid and permeate side temperature were maintained at 27.5 °C and 15 °C, respectively. For VMD, the feed liquid temperature was 27 °C and a vacuum of 94.8 kPa was applied on the permeate side. The maximum permeate flux achieved was 3.2 kg/m(2).h for VMD and 6.5 kg/m(2).h for DCMD. The salt rejection obtained was higher than 99.98%. The coated membranes showed a more stable flux than the uncoated membranes indicating that the double layered membranes have great potential in solving the pore wetting problem in MD. Copyright © 2015 Elsevier Ltd. All rights reserved.

Novel procedure to enhance PLA surface properties by chitosan irreversible immobilization

Energy Technology Data Exchange (ETDEWEB)

Stoleru, Elena; Dumitriu, Raluca Petronela [Petru Poni Institute of Macromolecular Chemistry, Grigore Ghica Voda Alley, 41A, 700487 Iasi (Romania); Munteanu, Bogdanel Silvestru [“Al. I. Cuza” University, Faculty of Physics, 11 Carol I Blvd., 700506 Iasi (Romania); Zaharescu, Traian [INCDIE ICPE CA, Bucharest (Romania); Tănase, Elisabeta Elena; Mitelut, Amalia [Industrial Biotechnology Department, Faculty of Biotechnology – USAMV Bucharest (Romania); Ailiesei, Gabriela-Liliana [Petru Poni Institute of Macromolecular Chemistry, Grigore Ghica Voda Alley, 41A, 700487 Iasi (Romania); Vasile, Cornelia, E-mail: cvasile@icmpp.ro [Petru Poni Institute of Macromolecular Chemistry, Grigore Ghica Voda Alley, 41A, 700487 Iasi (Romania)

2016-03-30

Graphical abstract: - Highlights: • PLA requires functionalization prior to surface attaching chitosan. • Chitosan with different molecular weights was grafted onto PLA surface. • Antibacterial, antifungal, antioxidant PLA-based materials are obtained. • Nano-fibers coatings obtained by electrospinning of high molecular weight chitosan. - Abstract: A novel two step procedure was applied for poly(lactic acid) (PLA) functionalization consisting in the exposure to cold radiofrequency plasma in nitrogen atmosphere or to gamma irradiation followed by “grafting to” of a chitosan layer using carbodiimide chemistry. The adhesion and stability of the deposited surface layer was assured by plasma/gamma irradiation treatment while the chitosan layer offers antifungal/antibacterial/antioxidant activities. Chitosan with different viscosities/deacetylation degree was deposited by electrospinning or immersion methods. Correlations between rheological behavior of chitosan solutions and chitosan layer deposition conditions are made. The PLA surface properties were investigated by water contact angle measurements, ATR-FTIR spectroscopy, AFM, chemiluminiscence, etc. It has been established that the surface roughness increases direct proportional with cold plasma duration and gamma irradiation dose and further increases by chitosan coating which at its turn depends on chitosan characteristics (viscosity and deacetylation degree) and method of deposition. Nano-fibers with relatively homogeneous and reproducible features are obtained by electrospinning of highly viscous chitosan while with the other two types of chitosan both microparticles and nano-fibers are formed. The chitosan coating obtained by immersion is more homogenous and compact and has a better antibacterial activity than the electrospun layer as fiber meshes.

Impact of edible chitosan-cassava starch coatings enriched with Lippia gracilis Schauer genotype mixtures on the shelf life of guavas (Psidium guajava L.) during storage at room temperature.

Science.gov (United States)

de Aquino, Alana Bezerra; Blank, Arie Fitzgerald; Santana, Luciana Cristina Lins de Aquino

2015-03-15

The effect of edible chitosan-cassava starch (CH-CS) coatings containing a mixture of Lippia gracilis Schauer genotypes (EOM) on the shelf life of guavas during storage at room temperature for 10 days was studied. Sixteen formulations were prepared with a range of chitosan and essential oil mixtures concentrations, and the in vitro antimicrobial activity was tested. Formulations containing 2.0% cassava starch, 2.0% chitosan and 1.0%, 2.0% or 3.0% EOM were most effective in inhibiting the growth of the majority of bacteria. The edible CH-CS coating and CH-CS with 1.0% (CH-CS-EOM1) or 3.0% EOM (CH-CS-EOM3) were added to guavas and the shelf life was evaluated. On the tenth day of storage, total aerobic mesophilic bacteria and mould and yeast counts were statistically lower (p<0.05) in the CH-CS-EOM1- or CH-CS-EOM3-coated fruits than CH-CS-coated fruits. In addition, fruits coated with CH-CS or CH-CS-EOM showed no significant changes of total soluble solids content, while CH-CS-EOM-coated fruits showed lower titratable acidity than CH-CS-coated fruits at the end of storage. CH-CS-EOM3-coated guavas showed lower a(∗) and b(∗) values and higher L(∗) and hue values than those with other coatings. Copyright © 2014 Elsevier Ltd. All rights reserved.

Preparation and Adsorption Ability of Polysulfone Microcapsules Containing Modified Chitosan Gel

Institute of Scientific and Technical Information of China (English)

CHEN Fei; LUO Guangsheng; YANG Weiwei; WANG Yujun

2005-01-01

Chemically modified chitosan beads containing polyethyleneimine (PEI) were prepared to improve the metal ion adsorption capacity of the chitosan beads and their mechanical stability and to limit their biodegradability. The modified beads were encapsulated with the polymer material polysulfone by a novel surface coating method named the emulsion phase inversion method. The adsorption properties of the modified beads and the microstructures of the polysulfone coating layer were then analyzed. The experimental results showed that the PEI was successfully linked onto the chitosan beads. The density of the -NH2 groups in the modified beads was significantly increased, while the water content was reduced. The coating layer thickness was about 200 (m. The modified chitosan gel beads had excellent Cu(II) adsorption capacity, with a maximum Cu(II) adsorption capacity 1.34 times higher than that of the unmodified beads. The results show that even with the polysulfone coating the adsorption kinetics of the modified beads is still better than those of the unmodified beads. The modifications improve the mass transfer performance of the chitosan beads as well as the bead stability.

Dynamic coating of mf/uf membranes for fouling mitigation

KAUST Repository

Tabatabai, S. Assiyeh Alizadeh

2017-01-19

A membrane system including an anti-fouling layer and a method of applying an anti-fouling layer to a membrane surface are provided. In an embodiment, the surface is a microfiltration (MF) or an ultrafiltration (UF) membrane surface. The anti-fouling layer can include a stimuli responsive layer and a dynamic protective layer applied over the stimuli responsive layer that can be a coating on a surface of the membrane. The stimuli responsive polymer layer can act as an adhesive prior to coating with the dynamic protective layer to aid in adhering the dynamic protective layer to the membrane surface. The dynamic protective layer can be formed by suitable nanoparticles that can prevent adhesion of foulants directly to the membrane surface. The stimuli responsive layer can be responsive to physio- chemical stimuli to cause a release of the stimuli responsive layer and the dynamic protective layer including foulants from the membrane.

Drug delivery glucantime in PVP/chitosan membranes

Energy Technology Data Exchange (ETDEWEB)

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

2015-07-01

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

Drug delivery glucantime in PVP/chitosan membranes

International Nuclear Information System (INIS)

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

2015-01-01

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

Liposomes coated with thiolated chitosan enhance oral peptide delivery to rats.

Science.gov (United States)

Gradauer, K; Barthelmes, J; Vonach, C; Almer, G; Mangge, H; Teubl, B; Roblegg, E; Dünnhaupt, S; Fröhlich, E; Bernkop-Schnürch, A; Prassl, R

2013-12-28

The aim of the present study was the in vivo evaluation of thiomer-coated liposomes for an oral application of peptides. For this purpose, salmon calcitonin was chosen as a model drug and encapsulated within liposomes. Subsequently, the drug loaded liposomes were coated with either chitosan-thioglycolic acid (CS-TGA) or an S-protected version of the same polymer (CS-TGA-MNA), leading to an increase in the particle size of about 500 nm and an increase in the zeta potential from approximately -40 mV to a maximum value of about +44 mV, depending on the polymer. Coated liposomes were demonstrated to effectively penetrate the intestinal mucus layer where they came in close contact with the underlying epithelium. To investigate the permeation enhancing properties of the coated liposomes ex vivo, we monitored the transport of fluoresceinisothiocyanate-labeled salmon calcitonin (FITC-sCT) through rat small intestine. Liposomes coated with CS-TGA-MNA showed the highest effect, leading to a 3.8-fold increase in the uptake of FITC-sCT versus the buffer control. In vivo evaluation of the different formulations was carried out by the oral application of 40 μg of sCT per rat, either encapsulated within uncoated liposomes, CS-TGA-coated liposomes or CS-TGA-MNA-coated liposomes, or given as a solution serving as negative control. The blood calcium level was monitored over a time period of 24h. The highest reduction in the blood calcium level, to a minimum of 65% of the initial value after 6h, was achieved for CS-TGA-MNA-coated liposomes. Comparing the areas above curves (AAC) of the blood calcium levels, CS-TGA-MNA-coated liposomes led to an 8.2-fold increase compared to the free sCT solution if applied orally in the same concentration. According to these results, liposomes coated with S-protected thiomers have demonstrated to be highly valuable carriers for enhancing the oral bioavailability of salmon calcitonin. © 2013. Published by Elsevier B.V. All rights reserved.

Trans-membrane electron transfer in red blood cells immobilized in a chitosan film on a glassy carbon electrode

International Nuclear Information System (INIS)

Yu, Chunmei; Wang, Li; Zhu, Zhenkun; Bao, Ning; Gu, Haiying

2014-01-01

We have studied the trans-membrane electron transfer in human red blood cells (RBCs) immobilized in a chitosan film on a glassy carbon electrode (GCE). Electron transfer results from the presence of hemoglobin (Hb) in the RBCs. The electron transfer rate (k s ) of Hb in RBCs is 0.42 s −1 , and <1.13 s −1 for Hb directly immobilized in the chitosan film. Only Hb molecules in RBCs that are closest to the plasma membrane and the surface of the electrode can undergo electron transfer to the electrode. The immobilized RBCs displayed sensitive electrocatalytic response to oxygen and hydrogen peroxide. It is believed that this cellular biosensor is of potential significance in studies on the physiological status of RBCs based on observing their electron transfer on the modified electrode. (author)

Chitosan/polyanion surface modification of styrene-butadiene-styrene block copolymer membrane for wound dressing.

Science.gov (United States)

Yang, Jen Ming; Yang, Jhe-Hao; Huang, Huei Tsz

2014-01-01

The surface of styrene-butadiene-styrene block copolymer (SBS) membrane is modified with tri-steps in this study. At first, two step modified SBS membrane (MSBS) was prepared with epoxidation and ring opening reaction with maleated ionomer. Then chitosan was used as the polycation electrolyte and sodium alginate, poly(γ-glutamic acid) (PGA) and poly(aspartic acid) (PAsp) were selected as polyanion electrolytes to deposit on the surfaces of MSBS membrane by the layer-by-layer self-assembly (LbL) deposition technique to get three [chitosan/polyanion] LbL modified SBS membranes, ([CS/Alg], [CS/PGA] and [CS/PAsp]). From the quantitative XPS analysis and water contact angle measurement, it is found that the order of wettability and the content of functional group percentages of COO(-) and OCN on the three [CS/polyanion] systems are [CS/Alg]>[CS/PGA]>[CS/PAsp]. Performances of water vapor transmission rates, fibronectin adsorption, antibacterial assessment and 3T3 fibroblast cell growth on [CS/Alg], [CS/PGA] and [CS/PAsp] membranes were also evaluated. With the evaluation of water vapor transmission rate, these [CS/Alg], [CS/PGA] and [CS/PAsp] membranes are sterile semipermeable with water evaporation at about 82±8g/day·m(2). It is found that the amount of fibronectin adsorption on the three [CS/polyanion] systems is significantly determined by the sum of the functional group of COO(-) and OCN on the surfaces of [CS/Alg], [CS/PGA] and [CS/PAsp] systems. The results are inverse with the sum of the functional group of COO(-) and OCN on the three [CS/polyanion]. From the cytotoxicity test and cell adhesion and proliferation assay of 3T3 fibroblasts on the three [CS/polyanion] systems, it revealed that the cells not only remained viable but they also proliferated on the surfaces of [CS/Alg], [CS/PGA] and [CS/PAsp]. The bactericidal activity was found on [CS/Alg], [CS/PGA] and [CS/PAsp]. The transport of bacterial through these [CS/polyanion] membranes was also conducted

Preparation of antifouling poly(vinylidene fluoride) membranes via different coating methods using a zwitterionic copolymer

International Nuclear Information System (INIS)

Ma, Wenzhong; Rajabzadeh, Saeid; Matsuyama, Hideto

2015-01-01

Graphical abstract: - Highlights: • We successfully coated the poly(MPC-co-BMA) copolymer on the ultrafiltration membrane. • The hydrophilicity and antifouling were improved by coating poly(MPC-co-BMA). • The flow-through method showed better anti-fouling properties compared with immersion method. • P(MPC-co-BMA) was quite stable on the coated membranes. - Abstract: To reduce the fouling resistance of poly(vinylidene fluoride) membranes, a copolymer of 2-methacryloyloxyethyl phosphorylcholine (MPC) and n-butyl methacrylate (BMA) [poly(MPC-co-BMA)] was coated on a membrane and into its pores from an aqueous solution using two different methods, the immersion and flow-through methods. The effects of poly(MPC-co-BMA) coating on the water flux, surface morphology, and fouling propensity of three types of commercial ultrafiltration membranes with molecular-weight cutoffs ranging from 50 to 250 kDa were investigated. The fouling resistances of modified membranes to bovine serum albumin were compared to those of the unmodified membranes. The evaluation of X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy of the modified membranes confirmed that poly(MPC-co-BMA) was coated on the membrane surfaces. Although both modification methods effectively prevented protein fouling, the flow-through coating method demonstrated a better antifouling propensity. The coated copolymer stability results indicated that the coated copolymer layer on the membrane surface using both coating methods was quite stable even after ultrasonic treatment.

Preparation of antifouling poly(vinylidene fluoride) membranes via different coating methods using a zwitterionic copolymer

Energy Technology Data Exchange (ETDEWEB)

Ma, Wenzhong; Rajabzadeh, Saeid; Matsuyama, Hideto, E-mail: matuyama@kobe-u.ac.jp

2015-12-01

Graphical abstract: - Highlights: • We successfully coated the poly(MPC-co-BMA) copolymer on the ultrafiltration membrane. • The hydrophilicity and antifouling were improved by coating poly(MPC-co-BMA). • The flow-through method showed better anti-fouling properties compared with immersion method. • P(MPC-co-BMA) was quite stable on the coated membranes. - Abstract: To reduce the fouling resistance of poly(vinylidene fluoride) membranes, a copolymer of 2-methacryloyloxyethyl phosphorylcholine (MPC) and n-butyl methacrylate (BMA) [poly(MPC-co-BMA)] was coated on a membrane and into its pores from an aqueous solution using two different methods, the immersion and flow-through methods. The effects of poly(MPC-co-BMA) coating on the water flux, surface morphology, and fouling propensity of three types of commercial ultrafiltration membranes with molecular-weight cutoffs ranging from 50 to 250 kDa were investigated. The fouling resistances of modified membranes to bovine serum albumin were compared to those of the unmodified membranes. The evaluation of X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy of the modified membranes confirmed that poly(MPC-co-BMA) was coated on the membrane surfaces. Although both modification methods effectively prevented protein fouling, the flow-through coating method demonstrated a better antifouling propensity. The coated copolymer stability results indicated that the coated copolymer layer on the membrane surface using both coating methods was quite stable even after ultrasonic treatment.

Cellular processes and pathways that protect Saccharomyces cerevisiae cells against the plasma membrane-perturbing compound chitosan.

NARCIS (Netherlands)

Zakrzewska, A.M.; Boorsma, A.; Delneri, D.; Brul, S.; Oliver, S.G.; Klis, F.M.

2007-01-01

Global fitness analysis makes use of a genomic library of tagged deletion strains. We used this approach to study the effect of chitosan, which causes plasma membrane stress. The data were analyzed using T-profiler, which was based on determining the sensitivities of groups of deletion strains to

Morphology characterization and biocompatibility study of PLLA (Poly-L-Llactid-Acid) coating chitosan as stent for coronary heart disease

Science.gov (United States)

Widiyanti, Prihartini; Paramadini, Adanti W.; Jabbar, Hajria; Fatimah, Inas; Nisak, Fadila N. K.; Puspitasari, Rahma A.

2016-03-01

Cardiovascular disease is a global disease with high urgency. In the severe case of coronary heart disease while a blockage in the coronary arteries reach 75% or more, the patient required stent implantation. Stents are made of metal which has many limitations that can lead to blood clots and stent incompatibility toward the size of the blood vessels. There is a metal stent replacement solution that made from polymer material which is biocompatible. PLLA also has biocompatibility and good mechanical strength. PLLA stent will be coated with chitosan as a candidate for drug-coated stents which is able to work as a drug carrier. The aim of this study is to know the morphology information and biocompability status of PLLA coating chitosan as candidate of heart stent. Morphological results using SEM showed a smooth surface structure which reinforced clinical standard of stent material. Results of cytotoxicity test by MTT Assay method showed that the result of four samples in this experiment living cells is reached 90% which is non toxic and safe to use in the human body. %). The conclusion of this study is PLLA is polymer has potency to be used as stent material.

Development of multifunctional nano/ultrafiltration membrane based on a chitosan thin film on alginate electrospun nanofibres

CSIR Research Space (South Africa)

Mokhena, Teboho C

2017-07-01

Full Text Available of Chemistry, University of the Free State (Qwaqwa Campus), Phuthaditjhaba, South Africa 3 Center for Advanced Materials, Qatar University, Doha, Qatar Abstract The aim of this study was to develop a high flux three-tier composite membrane composed of a... of multifunctional nano/ultrafiltration membrane based on a chitosan thin film on alginate electrospun nanofibres T.C. Mokhena1,2, A.S. Luyt3* 1 CSIR Materials Science and Manufacturing, Polymers and Composites, Port Elizabeth, South Africa. 2 Department...

Chitosan membrane development and design of equipment for the removal of heavy metals from water

International Nuclear Information System (INIS)

Mora Molina, Jesus; Chaves Barquero, Luis; Araya Marchena, Mario; Starbird Perez, Ricardo

2012-01-01

A filtration technique has compared with 1,75% m/v chitosan membranes, crosslinked with glutaraldehyde (0,08% m/v) and without cross link, to quantify the removal capacity of chromium, copper and cadmium ions of model solutions. In addition, a simple and low cost equipment was developed to use with prepared membranes. The main goal has been to use biodegradable materials for removing heavy metals from water, through a low energy consumption, cheap, and applicable to specific problems. Two data sheets were prepared for the membranes and was found that chromium was the metal with the highest removal from water, by using a crosslinked membrane. Metal adsorption was best adjusted to the Freundlich isotherm model, better than Langmuir isotherm model. However, no correlation has been found between pore size of the membranes and crosslinking degree. (author) [es

Chitosan membrane development and design of equipment for the removal of heavy metals from water

International Nuclear Information System (INIS)

Mora Molina, Jesus; Starbird Perez, Ricardo; Chaves Barquero, Luis; Araya Marchena, Mario

2011-01-01

A filtration technique has compared with 1,75% m/v chitosan membranes, crosslinked with glutaraldehyde (0,08% m/v) and without cross link, to quantify the removal capacity of chromium, copper and cadmium ions of model solutions. In addition, a simple and low cost equipment was developed to use with prepared membranes. The main goal has been to use biodegradable materials for removing heavy metals from water, through a low energy consumption, cheap, and applicable to specific problems. Two data sheets were prepared for the membranes and was found that chromium was the metal with the highest removal from water, by using a crosslinked membrane. Metal adsorption was best adjusted to the Freundlich isotherm model, better than Langmuir isotherm model. However, no correlation has been found between pore size of the membranes and crosslinking degree. (author) [es

Adherence of paclitaxel drug in magnetite chitosan nanoparticles

International Nuclear Information System (INIS)

Escobar Zapata, Edna V.; Martínez Pérez, Carlos A.; Rodríguez González, Claudia A.; Castro Carmona, Javier S.; Quevedo Lopez, Manuel A.; García-Casillas, Perla E.

2012-01-01

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

STUDI MEMBRAN KITOSAN DARI KULIT LOBSTER BAMBU SEBAGAI MEMBRAN FILTRASI

Directory of Open Access Journals (Sweden)

Ni Nyoman Putri Windari

2016-02-01

Full Text Available The study of the extraction and characterization of chitosan from skin waste of Bamboo Lobster (Panulirus versicolor has been done. Chitosan is extracted using conventional method, namely the initial process: cleaning and drying (pretreatment, demineralization, deproteination, and deacetylation. The chitosan obtained has been used to prepare chitosan membrane 2% with acetic acid 1% as solvent. The membrane prepared by phase inversion method withprecipitation through solvent evaporation. The prepared membranes were characterized by FTIR spectrophotometer, Nova 1200e by BJH method and filtration method. The results obtained that degree of deacetylation (DD of chitosan is 70.016%. The thickness of the membrane is 0.361 mm. The FTIR spectra show that functional groups obtained are -NH, -CH, C=O, C-O and -CN. From BJH method obtained that the pore radius is 1.69 nm and pore density is 8.95 x 105pores/m3. From the filtration method obtained that at each pressure, 80-85 kPa and 90-100 kPa, the PWF values are 381.232 and 454.545 L/m2.h, respectively.

Synthesis and characterization of magnesium gluconate contained poly(lactic-co-glycolic acid)/chitosan microspheres

Energy Technology Data Exchange (ETDEWEB)

Rahman, Shekh M. [Department of Chemical, Biological and Bioengineering, North Carolina A& T State University, 1601 East Market Street, Greensboro, NC 27411 (United States); NSF Engineering Research Center for Revolutionizing Metallic Biomaterials, North Carolina A& T State University, Greensboro, NC 27411 (United States); Mahoney, Christopher [Department of Bioengineering, University of Pittsburgh, 4200 Fifth Avenue, Pittsburgh, PA 15250 (United States); Sankar, Jagannathan [NSF Engineering Research Center for Revolutionizing Metallic Biomaterials, North Carolina A& T State University, Greensboro, NC 27411 (United States); Department of Mechanical Engineering, North Carolina A& T State University, 1601 East Market Street, Greensboro, NC 27411 (United States); Marra, Kacey G. [NSF Engineering Research Center for Revolutionizing Metallic Biomaterials, North Carolina A& T State University, Greensboro, NC 27411 (United States); Department of Bioengineering, University of Pittsburgh, 4200 Fifth Avenue, Pittsburgh, PA 15250 (United States); Department of Plastic Surgery, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15250 (United States); McGowan Institute for Regenerative Medicine, University of Pittsburgh, 450 Technology Drive, Pittsburgh, PA 15250 (United States); Bhattarai, Narayan, E-mail: nbhattar@ncat.edu [Department of Chemical, Biological and Bioengineering, North Carolina A& T State University, 1601 East Market Street, Greensboro, NC 27411 (United States); NSF Engineering Research Center for Revolutionizing Metallic Biomaterials, North Carolina A& T State University, Greensboro, NC 27411 (United States)

2016-01-15

Graphical abstract: - Highlights: • Magnesium gluconate contained PLGA/chitosan microspheres were fabricated. • In vitro release of magnesium ions was performed using Xylidyl Blue assay. • Chitosan coated PLGA can significantly control the release of magnesium ions. • Cellular compatibility was tested using adipose-derived stem cells and PC12 cells. • The cells encounter acceptably low levels of damage in contact with microspheres. - Abstract: The goal of this study was to fabricate and investigate the chitosan coated poly(lactic-co-glycolic acid) (PLGA) microspheres for the development of controlled release magnesium delivery system. PLGA based microspheres are ideal vehicles for many controlled release drug delivery applications. Chitosan is a naturally occurring biodegradable and biocompatible polysaccharide, which can coat the surface of PLGA to alter the release of drugs. Magnesium gluconate (MgG) was encapsulated in the PLGA and PLGA/chitosan microspheres by utilizing the double emulsion solvent evaporation technique for controlled release study. The microspheres were tested with respect to several physicochemical and biological properties, including morphology, chemical structure, chitosan adsorption efficiency, magnesium encapsulation efficiency, in vitro release of magnesium ions, and cellular compatibility using both human adipose-derived stem cells (ASCs) and PC12 cells. Chitosan coated PLGA microspheres can significantly control the release of magnesium ions compared to uncoated PLGA microspheres. Both coated and uncoated microspheres showed good cellular compatibility.

Surface modification of orthodontic implants by nanocomposite coatings based on chitosan and metals

Directory of Open Access Journals (Sweden)

Suetenkov D.Ye.

2013-09-01

Full Text Available Purpose: to study the properties of nanostructured coatings in orthodontic implants. Material and methods. Low and average molecular mass chitosan, 3-amynopropil-3-methoxysylan and suspensions of 5 nm and 10 nm gold nano-spheres stabilized with natrium citrate were used for nanocomposed surfaces. 2mg/ml polyethylenamin water solution was used for making the underlayer before putting polyion coverage using «POLYION-1M». The polyion covering dynamics was studied by polyquartz weighing method. Morphology of created layers was studied with atomic microscopy, elements were studied by secondary ion mass-spectrometry. Results. The best transmission among structures of chito-san/metals was showed by low molecular mass of chitosan and 8-1 Onm nanoparticles of metals. Analysis of roughness of surface shows that nanoparticles of gold make the most solid surface on 3-amynopropil-3-methoxysylan underlayer. Conclusion. The development of biocomparative materials in maxillofacial surgery is considered to be effective method of decreasing the risk of post-operative inflammatory complications by local antibacterial effect.

Chitosan-coated magnetic nanoparticles prepared in one-step by precipitation in a high-aqueous phase content reverse microemulsion.

Science.gov (United States)

Pineda, María Guadalupe; Torres, Silvia; López, Luis Valencia; Enríquez-Medrano, Francisco Javier; de León, Ramón Díaz; Fernández, Salvador; Saade, Hened; López, Raúl Guillermo

2014-07-02

Chitosan-coated magnetic nanoparticles (CMNP) were prepared in one-step by precipitation in a high-aqueous phase content reverse microemulsion in the presence of chitosan. The high-aqueous phase concentration led to productivities close to 0.49 g CMNP/100 g microemulsion; much higher than those characteristic of precipitation in reverse microemulsions for preparing magnetic nanoparticles. The obtained nanoparticles present a narrow particle size distribution with an average diameter of 4.5 nm; appearing to be formed of a single crystallite; furthermore they present superparamagnetism and high magnetization values; close to 49 emu/g. Characterization of CMNP suggests that chitosan is present as a non-homogeneous very thin layer; which explains the slight reduction in the magnetization value of CMNP in comparison with that of uncoated magnetic nanoparticles. The prepared nanoparticles show high heavy ion removal capability; as demonstrated by their use in the treatment of Pb2+ aqueous solutions; from which lead ions were completely removed within 10 min.

Chitosan-Coated Magnetic Nanoparticles Prepared in One-Step by Precipitation in a High-Aqueous Phase Content Reverse Microemulsion

Directory of Open Access Journals (Sweden)

María Guadalupe Pineda

2014-07-01

Full Text Available Chitosan-coated magnetic nanoparticles (CMNP were prepared in one-step by precipitation in a high-aqueous phase content reverse microemulsion in the presence of chitosan. The high-aqueous phase concentration led to productivities close to 0.49 g CMNP/100 g microemulsion; much higher than those characteristic of precipitation in reverse microemulsions for preparing magnetic nanoparticles. The obtained nanoparticles present a narrow particle size distribution with an average diameter of 4.5 nm; appearing to be formed of a single crystallite; furthermore they present superparamagnetism and high magnetization values; close to 49 emu/g. Characterization of CMNP suggests that chitosan is present as a non-homogeneous very thin layer; which explains the slight reduction in the magnetization value of CMNP in comparison with that of uncoated magnetic nanoparticles. The prepared nanoparticles show high heavy ion removal capability; as demonstrated by their use in the treatment of Pb2+ aqueous solutions; from which lead ions were completely removed within 10 min.

Effects of Polysaccharide-Based Edible Coatings on Quality and Antioxidant Enzyme System of Strawberry during Cold Storage

Directory of Open Access Journals (Sweden)

Li Li

2017-01-01

Full Text Available Strawberry is a nutritious, but highly perishable fruit. Three polysaccharide-based edible coatings (alginate, chitosan, and pullulan were applied to postharvest strawberry fruit during cold storage (4°C, and their effects on fruit quality and antioxidant enzyme system were investigated in the present study. The results showed that polysaccharide coatings showed a significant delay in fruit softening and rot and reduced changes in total soluble solid and titratable acidity content during 16 d storage. Polysaccharide coatings also maintained higher ascorbic acid and total phenolic contents than control from day 2 and significantly inhibited fruit decay and respiration after 12 d storage (p<0.05. Polysaccharide treatments enhanced the activities of antioxidant enzymes (peroxidase, catalase, superoxide dismutase, and ascorbate peroxidase so as to prevent lipid peroxidation and reduce membrane damage. Additionally, chitosan coating had the most positive effects on fruit quality amongst three polysaccharide-based edible coatings and presented the highest relative activities of antioxidant enzymes. These results indicated that polysaccharide-based edible coatings were helpful in postharvest quality maintenance of strawberry fruit.

Bovine Serum Albumin and Chitosan Coated Silver Nanoparticles and Its Antimicrobial Activity against Oral and Nonoral Bacteria

Directory of Open Access Journals (Sweden)

León Francisco Espinosa-Cristóbal

2015-01-01

Full Text Available Antimicrobial agents have been developed for drug-resistance infections, which have been rapidly increasing; however, the control of involved microorganisms is still a challenge. In this work, SNP with bovine serum albumin (BSA and chitosan (CS coatings were prepared with an aqueous reduction method, characterized using dispersion light scattering, transmission electron microscopy, and thermal analysis. Antibacterial activity was tested on seven oral and nonoral bacteria by microdilution test and scanning electron microscopy. Six different sizes and shapes of coated SNP were prepared and used. Characterization revealed narrow size and good distribution of particles, spherical and pseudospherical shapes, and the presence of coatings on the SNP surfaces. All samples showed antimicrobial activity, although smaller sizes and CS samples had the best inhibition effects. The highest microbial resistance was shown by Gram-positive bacteria. Although coated SNP action depends on particular bacterium, BSA and CS coated SNP could be used for drug-resistance infections.

Sacrificial Protective Coating Materials that can be Regenerated In-Situ to Enable High Performance Membranes

Energy Technology Data Exchange (ETDEWEB)

Malati, Peter; Ganguli, Rahul; Mehrotra, Vivek

2018-03-20

In the pulp and paper industry, weak black liquor concentration is carried out using energy intensive evaporators. Briefly, after wood digestion, water is evaporated to concentrate weak black liquor to the point where the black liquor can be burned in a recovery boiler, which ultimately leads to the recovery of digestion chemicals. Because it is less energy intensive than heat-driven separation, pressure-driven separation of water from black liquor using membranes could reduce the energy usage by 55 trillion Btu yr-1 and carbon dioxide emissions by more than 11 million metric tons CO2 per year if the first two evaporators are replaced. However, weak black liquor is a hot, corrosive, and highly fouling feed with organic molecules, colloids, and ions that clog membranes within hours of operation. We have shown that membrane-based concentration of weak black liquor is feasible, but only with our antifouling and anti-clogging technology that is based on a sacrificial Bio-inspired Living Skin concept. This concept is based on a conformal coating that is formed at the membrane surface and within the pores. Weak foulant adhesion dramatically decreases membrane fouling while the superhydrophilicity of the coating increases the water permeability. Moreover, the coating can be completely removed during backflushing, which removes foulants that may irreversibly adhere to the coating over long periods of time. The skin shedding completely regenerates the membrane surface and pores, restoring the original flux. This is followed by in-situ recoating, using the existing membrane plumbing and pumps, which essentially creates a brand new membrane surface. Our coatings resist fouling under hot weak black liquor concentration conditions and can be regenerated in-situ on demand. Weak black liquor permeate flux as well as Fourier-transform infrared spectroscopy results suggest that black liquor foulants adhere very weakly to coated membrane surfaces. We modified the coating process to

[Development of a novel absorbable nanofiber chitosan-collagen membrane by electrospinning and the preliminary study on guided bone regeneration].

Science.gov (United States)

Gao, B; Li, X J; Lin, M; Li, Y Y; Dong, Y

2018-02-09

Objective: To evaluate the application effect of nanofiber chitosan-collagen membrane (NCM) on guided bone regeneration (GBR). Methods: The mixture of collagen, chitosan, polyethylene oxide was used to make up the NCM by electrospinning, then the NCM was crosslinked by glutaraldehyde vapor. The physical property of the NCM was measured by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). MC3T3-E1 osteoblasts were cultured on NCM to characterize the biocompatibility. The effectiveness of four groups [contrast group, Bio-gide membrane (BGM), compressed chitosan-collagen menbrane (CCM), NCM/CCM] on bone regeneration were evaluated in critical-sized defects (diameter = 5 mm) in SD rats. Results: When the mixed solution consists of 4.0% collagen, 1.0% chitosan and 3.5% polyethylene oxide, the NCM could be validly fabricated by electrospinning. After cross-linking by glutaraldehyde vapor, the tensile strength and the stability of NCM in damp was enhanced. No cytotoxicity of the NCM was detected on MC3T3-E1 osteoblasts. In vivo study showed that the new bone regeneration ratio of NCM/CCM group was [(43.10±1.49)%], and this was similar to that of the group of BGM [(41.36±2.60)%] ( P> 0.05), but higher than that of the CCM group [(33.10±1.41)%] and the contrast group [(7.22±2.46)%] ( P< 0.05). Conclusions: The NCM can promote new bone regeneration effectively in GBR procedure.

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.

Surface modification of polyamide thin film composite membrane by coating of titanium dioxide nanoparticles

Directory of Open Access Journals (Sweden)

Thu Hong Anh Ngo

2016-12-01

Full Text Available In this paper, the coating of TiO2 nanoparticles onto the surface of a polyamide thin film composite nanofiltration membrane has been studied. Changes in the properties and separation performance of the modified membranes were systematically characterized. The experimental results indicated that the membrane surface hydrophilicity was significantly improved by the presence of the coated TiO2 nanoparticles with subsequent UV irradiation. The separation performance of the UV-irradiated TiO2-coated membranes was improved with a great enhancement of flux and a very high retention for removal of residual dye in an aqueous feed solution. The antifouling property of the UV-irradiated TiO2-coated membranes was enhanced with higher maintained flux ratios and lower irreversible fouling factors compared with an uncoated membrane.

Production of Galactooligosaccharides Using β-Galactosidase Immobilized on Chitosan-Coated Magnetic Nanoparticles with Tris(hydroxymethylphosphine as an Optional Coupling Agent

Directory of Open Access Journals (Sweden)

Su-Ching Chen

2015-06-01

Full Text Available β-Galactosidase was immobilized on chitosan-coated magnetic Fe3O4 nanoparticles and was used to produce galactooligosaccharides (GOS from lactose. Immobilized enzyme was prepared with or without the coupling agent, tris(hydroxymethylphosphine (THP. The two immobilized systems and the free enzyme achieved their maximum activity at pH 6.0 with an optimal temperature of 50 °C. The immobilized enzymes showed higher activities at a wider range of temperatures and pH. Furthermore, the immobilized enzyme coupled with THP showed higher thermal stability than that without THP. However, activity retention of batchwise reactions was similar for both immobilized systems. All the three enzyme systems produced GOS compound with similar concentration profiles, with a maximum GOS yield of 50.5% from 36% (w·v−1 lactose on a dry weight basis. The chitosan-coated magnetic Fe3O4 nanoparticles can be regenerated using a desorption/re-adsorption process described in this study.

Tri-bore PVDF hollow fibers with a super-hydrophobic coating for membrane distillation

KAUST Repository

Lu, Kang-Jia; Zuo, Jian; Chung, Tai-Shung

2016-01-01

Membranes with good mechanical strength, high vapor flux and outstanding anti-wetting properties are essential for membrane distillation (MD) applications. In this work, porous polyvinylidene fluoride (PVDF) tri-bore hollow fiber membranes with super-hydrophobicity are developed to achieve these desired properties. The tri-bore hollow fiber offers better mechanical strength than the conventional single-bore fiber. To improve its anti-wetting properties, Teflon® AF 2400 is coated on the membrane surface. The effects of coating on membrane morphology, performance and anti-wetting properties have been thoroughly investigated. With an optimal coating condition (0.025 wt% of Teflon® AF 2400, 30 s), a super-hydrophobic surface with a contact angle of 151o is achieved. The resultant membrane shows an increase of 109% in liquid entry pressure (LEP) with a slight sacrifice of 21% in flux. Long term direct contact MD tests have confirmed that the Teflon® AF 2400 coated membrane has enhanced stability with an average flux of 21 kg m-2 h-1 and rejection of 99.99% at 60 °° C for desalination application.

Tri-bore PVDF hollow fibers with a super-hydrophobic coating for membrane distillation

KAUST Repository

Lu, Kang-Jia

2016-04-26

Membranes with good mechanical strength, high vapor flux and outstanding anti-wetting properties are essential for membrane distillation (MD) applications. In this work, porous polyvinylidene fluoride (PVDF) tri-bore hollow fiber membranes with super-hydrophobicity are developed to achieve these desired properties. The tri-bore hollow fiber offers better mechanical strength than the conventional single-bore fiber. To improve its anti-wetting properties, Teflon® AF 2400 is coated on the membrane surface. The effects of coating on membrane morphology, performance and anti-wetting properties have been thoroughly investigated. With an optimal coating condition (0.025 wt% of Teflon® AF 2400, 30 s), a super-hydrophobic surface with a contact angle of 151o is achieved. The resultant membrane shows an increase of 109% in liquid entry pressure (LEP) with a slight sacrifice of 21% in flux. Long term direct contact MD tests have confirmed that the Teflon® AF 2400 coated membrane has enhanced stability with an average flux of 21 kg m-2 h-1 and rejection of 99.99% at 60 °° C for desalination application.

Adherence of paclitaxel drug in magnetite chitosan nanoparticles

Energy Technology Data Exchange (ETDEWEB)

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

2012-09-25

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

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

Science.gov (United States)

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

2014-07-15

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

Uncertainties of Gaseous Oxidized Mercury Measurements Using KCl-Coated Denuders, Cation-Exchange Membranes, and Nylon Membranes: Humidity Influences.

Science.gov (United States)

Huang, Jiaoyan; Gustin, Mae Sexauer

2015-05-19

Quantifying the concentration of gaseous oxidized mercury (GOM) and identifying the chemical compounds in the atmosphere are important for developing accurate local, regional, and global biogeochemical cycles. The major hypothesis driving this work was that relative humidity affects collection of GOM on KCl-coated denuders and nylon membranes, both currently being applied to measure GOM. Using a laboratory manifold system and ambient air, GOM capture efficiency on 3 different collection surfaces, including KCl-coated denuders, nylon membranes, and cation-exchange membranes, was investigated at relative humidity ranging from 25 to 75%. Recovery of permeated HgBr2 on KCl-coated denuders declined by 4-60% during spikes of relative humidity (25 to 75%). When spikes were turned off GOM recoveries returned to 60 ± 19% of permeated levels. In some cases, KCl-coated denuders were gradually passivated over time after additional humidity was applied. In this study, GOM recovery on nylon membranes decreased with high humidity and ozone concentrations. However, additional humidity enhanced GOM recovery on cation-exchange membranes. In addition, reduction and oxidation of elemental mercury during experiments was observed. The findings in this study can help to explain field observations in previous studies.

Heparin free coating on PLA membranes for enhanced hemocompatibility via iCVD

Science.gov (United States)

Wang, Hui; Shi, Xiao; Gao, Ailin; Lin, Haibo; Chen, Yongliang; Ye, Yumin; He, Jidong; Liu, Fu; Deng, Gang

2018-03-01

In the present work, we report one-step immobilization of nano-heparin coating on PLA membranes via initiated chemical vapor deposition (iCVD) for enhanced hemocompatibility. The nano-coating introduced onto the membrane surface via the crosslinking of P(MAA-EGDA) was confirmed by the FTIR, SEM and weight measurement respectively. The negative carboxyl groups could form the hydration interaction with the protein and platelets and electrostatic interaction with amide groups of thrombin by the mediation of antithrombin, which is similar but different with heparin. The P(MAA-EGDA) coated membranes showed suppressed platelet adhesion and prolonged clotting time (APTTs increased to 59 s, PTs increased to 20.4 s, TTs increased to 17.5 s, and the FIBs declined by 30 mg/dL). Moreover, the complement activation tests demonstrated the formation of C3a and C5a was inhibited. All results demonstrated that the nano-coating of P(MAA-EGDA) via iCVD significantly enhanced the hemocompatibility of PLA membranes, which is also applicable for various membranes.

Towards bio-silicon interfaces: Formation of an ultra-thin self-hydrated artificial membrane composed of dipalmitoylphosphatidylcholine (DPPC) and chitosan deposited in high vacuum from the gas-phase

Science.gov (United States)

Retamal, María J.; Cisternas, Marcelo A.; Gutierrez-Maldonado, Sebastian E.; Perez-Acle, Tomas; Seifert, Birger; Busch, Mark; Huber, Patrick; Volkmann, Ulrich G.

2014-09-01

The recent combination of nanoscale developments with biological molecules for biotechnological research has opened a wide field related to the area of biosensors. In the last years, device manufacturing for medical applications adapted the so-called bottom-up approach, from nanostructures to larger devices. Preparation and characterization of artificial biological membranes is a necessary step for the formation of nano-devices or sensors. In this paper, we describe the formation and characterization of a phospholipid bilayer (dipalmitoylphosphatidylcholine, DPPC) on a mattress of a polysaccharide (Chitosan) that keeps the membrane hydrated. The deposition of Chitosan (˜25 Å) and DPPC (˜60 Å) was performed from the gas phase in high vacuum onto a substrate of Si(100) covered with its native oxide layer. The layer thickness was controlled in situ using Very High Resolution Ellipsometry (VHRE). Raman spectroscopy studies show that neither Chitosan nor DPPC molecules decompose during evaporation. With VHRE and Atomic Force Microscopy we have been able to detect phase transitions in the membrane. The presence of the Chitosan interlayer as a water reservoir is essential for both DPPC bilayer formation and stability, favoring the appearance of phase transitions. Our experiments show that the proposed sample preparation from the gas phase is reproducible and provides a natural environment for the DPPC bilayer. In future work, different Chitosan thicknesses should be studied to achieve a complete and homogeneous interlayer.

Towards bio-silicon interfaces: Formation of an ultra-thin self-hydrated artificial membrane composed of dipalmitoylphosphatidylcholine (DPPC) and chitosan deposited in high vacuum from the gas-phase

International Nuclear Information System (INIS)

Retamal, María J.; Cisternas, Marcelo A.; Seifert, Birger; Volkmann, Ulrich G.; Gutierrez-Maldonado, Sebastian E.; Perez-Acle, Tomas; Busch, Mark; Huber, Patrick

2014-01-01

The recent combination of nanoscale developments with biological molecules for biotechnological research has opened a wide field related to the area of biosensors. In the last years, device manufacturing for medical applications adapted the so-called bottom-up approach, from nanostructures to larger devices. Preparation and characterization of artificial biological membranes is a necessary step for the formation of nano-devices or sensors. In this paper, we describe the formation and characterization of a phospholipid bilayer (dipalmitoylphosphatidylcholine, DPPC) on a mattress of a polysaccharide (Chitosan) that keeps the membrane hydrated. The deposition of Chitosan (∼25 Å) and DPPC (∼60 Å) was performed from the gas phase in high vacuum onto a substrate of Si(100) covered with its native oxide layer. The layer thickness was controlled in situ using Very High Resolution Ellipsometry (VHRE). Raman spectroscopy studies show that neither Chitosan nor DPPC molecules decompose during evaporation. With VHRE and Atomic Force Microscopy we have been able to detect phase transitions in the membrane. The presence of the Chitosan interlayer as a water reservoir is essential for both DPPC bilayer formation and stability, favoring the appearance of phase transitions. Our experiments show that the proposed sample preparation from the gas phase is reproducible and provides a natural environment for the DPPC bilayer. In future work, different Chitosan thicknesses should be studied to achieve a complete and homogeneous interlayer

Towards bio-silicon interfaces: Formation of an ultra-thin self-hydrated artificial membrane composed of dipalmitoylphosphatidylcholine (DPPC) and chitosan deposited in high vacuum from the gas-phase

Energy Technology Data Exchange (ETDEWEB)

Retamal, María J., E-mail: moretama@uc.cl; Cisternas, Marcelo A.; Seifert, Birger; Volkmann, Ulrich G. [Instituto de Física, Pontificia Universidad Católica de Chile, Avda. Vicuña Mackenna 4860, 7820436 Santiago (Chile); Centro de Investigación en Nanotecnología y Materiales Avanzados (CIEN-UC), Pontificia Universidad Católica de Chile, Avda. Vicuña Mackenna 4860, 7820436 Santiago (Chile); Gutierrez-Maldonado, Sebastian E.; Perez-Acle, Tomas [Computational Biology Lab (DLab), Fundación Ciencia y Vida, Av. Zañartu 1482, Santiago (Chile); Centro Interdisciplinario de Neurociencias de Valparaiso (CINV), Universidad de Valparaiso, Pasaje Harrington 287, Valparaiso (Chile); Busch, Mark; Huber, Patrick [Institute of Materials Physics and Technology, Hamburg University of Technology (TUHH), D-21073 Hamburg-Harburg (Germany)

2014-09-14

The recent combination of nanoscale developments with biological molecules for biotechnological research has opened a wide field related to the area of biosensors. In the last years, device manufacturing for medical applications adapted the so-called bottom-up approach, from nanostructures to larger devices. Preparation and characterization of artificial biological membranes is a necessary step for the formation of nano-devices or sensors. In this paper, we describe the formation and characterization of a phospholipid bilayer (dipalmitoylphosphatidylcholine, DPPC) on a mattress of a polysaccharide (Chitosan) that keeps the membrane hydrated. The deposition of Chitosan (∼25 Å) and DPPC (∼60 Å) was performed from the gas phase in high vacuum onto a substrate of Si(100) covered with its native oxide layer. The layer thickness was controlled in situ using Very High Resolution Ellipsometry (VHRE). Raman spectroscopy studies show that neither Chitosan nor DPPC molecules decompose during evaporation. With VHRE and Atomic Force Microscopy we have been able to detect phase transitions in the membrane. The presence of the Chitosan interlayer as a water reservoir is essential for both DPPC bilayer formation and stability, favoring the appearance of phase transitions. Our experiments show that the proposed sample preparation from the gas phase is reproducible and provides a natural environment for the DPPC bilayer. In future work, different Chitosan thicknesses should be studied to achieve a complete and homogeneous interlayer.

Reinforced nanohydroxyapatite/polyamide66 scaffolds by chitosan coating for bone tissue engineering.

Science.gov (United States)

Huang, Di; Zuo, Yi; Zou, Qin; Wang, Yanying; Gao, Shibo; Wang, Xiaoyan; Liu, Haohuai; Li, Yubao

2012-01-01

High porosity of scaffold is always accompanied by poor mechanical property; the aim of this study was to enhance the strength and modulus of the highly porous scaffold of nanohydroxyapatite/polyamide66 (n-HA/PA66) by coating chitosan (CS) and to investigate the effect of CS content on the scaffold physical properties and cytological properties. The results show that CS coating can reinforce the scaffold effectively. The compress modulus and strength of the CS coated n-HA/PA66 scaffolds are improved to 32.71 and 2.38 MPa, respectively, being about six times and five times of those of the uncoated scaffolds. Meanwhile, the scaffolds still exhibit a highly interconnected porous structure and the porosity is approximate about 78%, slightly lower than the value (84%) of uncoated scaffold. The cytological properties of scaffolds were also studied in vitro by cocultured with osteoblast-like MG63 cells. The cytological experiments demonstrate that the reinforced scaffolds display favorable cytocompatibility and have no significant difference with the uncoated n-HA/PA66 scaffolds. The CS reinforced n-HA/PA66 scaffolds can meet the basic mechanical requirement of bone tissue engineering scaffold, presenting a potential for biomedical application in bone reconstruction and repair. Copyright © 2011 Wiley Periodicals, Inc.

Characterization of antimicrobial properties on the growth of S. aureus of novel renewable blends of gliadins and chitosan of interest in food packaging and coating applications.

Science.gov (United States)

Fernandez-Saiz, P; Lagaron, J M; Hernandez-Muñoz, P; Ocio, M J

2008-05-10

The biocide properties of chitosan-based materials have been known for many years. However, typical antimicrobial formulations of chitosan, mostly chitosonium salts, are known to be very water sensitive materials which may impair their use in many application fields such as food packaging or food coating applications. This first work reports on the development and characterization of the antimicrobial properties of novel fully renewable blends of chitosan with more water-resistant gliadin proteins isolated from wheat gluten. Chitosan release to the nutrient broth from a wide range of blends was studied making use of the ninhydrin method. The results indicated that both pure chitosan and its blends with gliadins presented significant antimicrobial activity, which increased with increasing the amount of chitosan in the composite formulation as expected. The gliadins-chitosan blends showed good transparency and film-forming properties and better water resistance than pure chitosan. The release tests revealed that dissolution of the biocide glucosamine groups, i.e. the chitosan water soluble fractions, also increased with the amount of chitosan present in the formulation. The release of these groups was for the first time directly correlated with the antimicrobial properties exhibited by the blends. Thus, incorporation of chitosan into an insoluble biopolymer matrix was revealed as a very feasible strategy to generate novel chitosan-based antimicrobial materials with potential advantages, for instance active food packaging applications.

In-vitro bioactivity, biocorrosion and antibacterial activity of silicon integrated hydroxyapatite/chitosan composite coating on 316 L stainless steel implants

Energy Technology Data Exchange (ETDEWEB)

Sutha, S.; Kavitha, K.; Karunakaran, G.; Rajendran, V., E-mail: veerajendran@gmail.com

2013-10-15

A simple and effective ultrasonication method was applied for the preparation of 0, 0.4, 0.8, 1.0 and 1.6 wt% silicon substituted hydroxyapatite (HAp) (SH). The Ca/P ratio of the synthesised SH nanoparticles were in the range of 1.58–1.70. Morphological changes were noticed in HAp with respect to the amount of Si from 0 to 1.6 wt%. The morphology of the particles changed from spherical shape to rod-like morphology with respect to the amount of Si which was confirmed using transmission electron microscopy. X-ray diffraction studies confirm the formation of phase pure SH nanoparticles without any secondary phase. Chitosan (CTS) blended SH nanocomposites coating on surgical grade 316 L stainless steel (316 L SS) implant was made by spin coating technique. The surface of the coated implant was characterised using scanning electron microscopy which confirms the uniform coating without cracks and pores. The increased corrosion resistance of the 1.6 wt% of SH/CTS-coated SS implant in the simulated body fluid (SBF) indicates the long-term biostability of SH composite-coated ceramics in vitro than the 0 wt% SH/CTS. The testing of SH/CTS nanocomposites with gram-positive and gram-negative bacterial strains confirms that the antibacterial ability improves with the higher substitution of Si. In addition, formation of bone-like apatite layer on the SH/CTS-coated implant in SBF was studied through SEM analysis and it confirms the ability to increase the HAp formation on the surface of 1.0 wt% SH/CTS-coated 316 L SS implant. Highlights: • Hydroxyapatite particles are prepared with various silicon concentration • Prepared composites are blended with chitosan and coated on the implant • Corrosion resistance in simulated body fluid improves its stability • Increase in silicon concentration improves the antibacterial activity • Coated plate exhibit high in-vitro bioactivity in simulated body fluid.

In-vitro bioactivity, biocorrosion and antibacterial activity of silicon integrated hydroxyapatite/chitosan composite coating on 316 L stainless steel implants

International Nuclear Information System (INIS)

Sutha, S.; Kavitha, K.; Karunakaran, G.; Rajendran, V.

2013-01-01

A simple and effective ultrasonication method was applied for the preparation of 0, 0.4, 0.8, 1.0 and 1.6 wt% silicon substituted hydroxyapatite (HAp) (SH). The Ca/P ratio of the synthesised SH nanoparticles were in the range of 1.58–1.70. Morphological changes were noticed in HAp with respect to the amount of Si from 0 to 1.6 wt%. The morphology of the particles changed from spherical shape to rod-like morphology with respect to the amount of Si which was confirmed using transmission electron microscopy. X-ray diffraction studies confirm the formation of phase pure SH nanoparticles without any secondary phase. Chitosan (CTS) blended SH nanocomposites coating on surgical grade 316 L stainless steel (316 L SS) implant was made by spin coating technique. The surface of the coated implant was characterised using scanning electron microscopy which confirms the uniform coating without cracks and pores. The increased corrosion resistance of the 1.6 wt% of SH/CTS-coated SS implant in the simulated body fluid (SBF) indicates the long-term biostability of SH composite-coated ceramics in vitro than the 0 wt% SH/CTS. The testing of SH/CTS nanocomposites with gram-positive and gram-negative bacterial strains confirms that the antibacterial ability improves with the higher substitution of Si. In addition, formation of bone-like apatite layer on the SH/CTS-coated implant in SBF was studied through SEM analysis and it confirms the ability to increase the HAp formation on the surface of 1.0 wt% SH/CTS-coated 316 L SS implant. Highlights: • Hydroxyapatite particles are prepared with various silicon concentration • Prepared composites are blended with chitosan and coated on the implant • Corrosion resistance in simulated body fluid improves its stability • Increase in silicon concentration improves the antibacterial activity • Coated plate exhibit high in-vitro bioactivity in simulated body fluid

Influence of Sulfonated-Kaolin On Cationic Exchange Capacity Swelling Degree and Morphology of Chitosan/Kaolin Composites

Directory of Open Access Journals (Sweden)

Ozi Adi Saputra

2016-06-01

Full Text Available Preparation of sulfonated-kaolin (sKao has been conducted and used as filler on chitosan matrix via solution casting method, namely chitosan/sKao (Cs/sKao. Swelling degree, cationic exchange capacity and thermal stability were evaluated to determine chitosan/sKao membranes performance as proton exchange membrane in fuel cell. Functional group analysis of chitosan, sKao and synthesized products were studied using Fourier Transform Infra-Red (FTIR spectroscopy. In this study, swelling degree and swelling area of Cs/sKao are also studied to determine of membrane ability to swelling which compare to unmodified chitosan/kaolin (Cs/Kao. The presence of sKao in chitosan matrix was able to improve cationic exchange capacity (CEC which proved by morphological study of membrane surface after CEC test. Moreover, Thermal stability of Cs/sKao showed the membrane has meet requirement for PEM application.

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.

Preparation and characterization of blends containing silk fibroin and chitosan

International Nuclear Information System (INIS)

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

2009-01-01

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

Long-term Efficacy and Biocompatibility of Encapsulated Islet Transplantation With Chitosan-Coated Alginate Capsules in Mice and Canine Models of Diabetes.

Science.gov (United States)

Yang, Hae Kyung; Ham, Dong-Sik; Park, Heon-Seok; Rhee, Marie; You, Young Hye; Kim, Min Jung; Shin, Juyoung; Kim, On-You; Khang, Gilson; Hong, Tae Ho; Kim, Ji-Won; Lee, Seung-Hwan; Cho, Jae-Hyoung; Yoon, Kun-Ho

2016-02-01

Clinical application of encapsulated islet transplantation is hindered by low biocompatibility of capsules leading to pericapsular fibrosis and decreased islet viability. To improve biocompatibility, we designed a novel chitosan-coated alginate capsules and compared them to uncoated alginate capsules. Alginate capsules were formed by crosslinking with BaCl2, then they were suspended in chitosan solution for 10 minutes at pH 4.5. Xenogeneic islet transplantation, using encapsulated porcine islets in 1,3-galactosyltransferase knockout mice, and allogeneic islet transplantation, using encapsulated canine islets in beagles, were performed without immunosuppressants. The chitosan-alginate capsules showed similar pore size, islet viability, and insulin secretory function compared to alginate capsules, in vitro. Xenogeneic transplantation of chitosan-alginate capsules demonstrated a trend toward superior graft survival (P = 0.07) with significantly less pericapsular fibrosis (cell adhesion score: 3.77 ± 0.41 vs 8.08 ± 0.05; P transplantation. Allogeneic transplantation of chitosan-alginate capsules normalized the blood glucose level up to 1 year with little evidence of pericapsular fibrotic overgrowth on graft explantation. The efficacy and biocompatibility of chitosan-alginate capsules were demonstrated in xenogeneic and allogeneic islet transplantations using small and large animal models of diabetes. This capsule might be a potential candidate applicable in the treatment of type 1 diabetes mellitus patients, and further studies in nonhuman primates are required.

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)

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

Science.gov (United States)

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

2017-01-01

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

Characterizations of Chitosan-Based Polymer Electrolyte Photovoltaic Cells

International Nuclear Information System (INIS)

Buraidah, M.H.; Teo, L.P.; Majid, S.R.; Yahya, R.; Taha, R.M.; Arof, A.K.

2010-01-01

The membranes 55 wt.% chitosan-45 wt.% NH4I, 33 wt.% chitosan-27 wt.% NH4I-40 wt.% EC, and 27.5 wt.% chitosan-22.5 wt.%?NH4I-50 wt.% buthyl-methyl-imidazolium-iodide (BMII) exhibit conductivity of 3.73 x 10-7, 7.34x10-6, and 3.43x10-5 S cm -1 , respectively, at room temperature. These membranes have been used in the fabrication of solid-state solar cells with configuration ITO/TiO 2 /polymer electrolyte membrane/ITO. It is observed that the short-circuit current density increases with conductivity of the electrolyte. The use of anthocyanin pigment obtained by solvent extraction from black rice and betalain from the callus of Celosia plumosa also helps to increase the short-circuit current.

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.

Preparation and characterization of underwater superoleophobic chitosan/poly(vinyl alcohol) coatings for self-cleaning and oil/water separation

International Nuclear Information System (INIS)

Wang, Qian; Fu, Youjia; Yan, Xiaoxia; Chang, Yanjiao; Ren, Lili; Zhou, Jiang

2017-01-01

Highlights: • Underwater superoleophobic CS/PVA coatings were prepared using a facile method. • Immersion in NaOH solution was crucial to enhance roughness of the coating surface. • Effects of coating composition on wettability of coating surface were investigated. • The CS/PVA coatings possess self-cleaning property. • The CS/PVA coatings can be used for oil/water separation with high efficiency. - Abstract: In this paper, chitosan (CS)/poly(vinyl alcohol) (PVA) coatings cross-linked with glutaraldehyde (GA) were prepared. Effects of the coating composition and NaOH solution treatment on surface morphology and topography were investigated by scanning electron microscope and atomic force microscope. It was found that the process of immersing the CS/PVA coatings into NaOH solution was crucial to enhance rough structure on the coating surface. The rough surface structure and the hydrophilic groups of CS and PVA made the CS/PVA coatings possess underwater superoleophobicity and low adhesion to oil. Oil contact angle of the prepared CS/PVA coatings was up to 161° and slide angle was only 3°. Moreover, the CS/PVA coatings showed stable superoleophobicity in high salt, strong acidic, and alkaline environments as well as underwater self-cleaning property and excellent transparency. The CS/PVA coatings could be used for gravity driven oil/water separation with high efficiency.

Preparation and characterization of underwater superoleophobic chitosan/poly(vinyl alcohol) coatings for self-cleaning and oil/water separation

Energy Technology Data Exchange (ETDEWEB)

Wang, Qian; Fu, Youjia; Yan, Xiaoxia; Chang, Yanjiao; Ren, Lili; Zhou, Jiang

2017-08-01

Highlights: • Underwater superoleophobic CS/PVA coatings were prepared using a facile method. • Immersion in NaOH solution was crucial to enhance roughness of the coating surface. • Effects of coating composition on wettability of coating surface were investigated. • The CS/PVA coatings possess self-cleaning property. • The CS/PVA coatings can be used for oil/water separation with high efficiency. - Abstract: In this paper, chitosan (CS)/poly(vinyl alcohol) (PVA) coatings cross-linked with glutaraldehyde (GA) were prepared. Effects of the coating composition and NaOH solution treatment on surface morphology and topography were investigated by scanning electron microscope and atomic force microscope. It was found that the process of immersing the CS/PVA coatings into NaOH solution was crucial to enhance rough structure on the coating surface. The rough surface structure and the hydrophilic groups of CS and PVA made the CS/PVA coatings possess underwater superoleophobicity and low adhesion to oil. Oil contact angle of the prepared CS/PVA coatings was up to 161° and slide angle was only 3°. Moreover, the CS/PVA coatings showed stable superoleophobicity in high salt, strong acidic, and alkaline environments as well as underwater self-cleaning property and excellent transparency. The CS/PVA coatings could be used for gravity driven oil/water separation with high efficiency.

Improvement of interaction between PVA and chitosan via magnetite nanoparticles for drug delivery application.

Science.gov (United States)

Shagholani, Hamidreza; Ghoreishi, Sayed Mehdi; Mousazadeh, Mohammad

2015-01-01

Magnetite nanoparticles were synthesized by coprecipitation under ultrasonication followed by coating with chitosan. Polyvinyl alcohol (PVA) is then combined with the chitosan that coated the magnetite nanoparticles. The combination occurs by hydrogen binding and ionic cross-linking of the amino and hydroxyl groups of chitosan and PVA respectively. The magnetite nanoparticles have an average size of 10.62 nm that was confirmed by TEM. The VSM measurements showed that nanoparticles were superparamagnetic. The coatings on the core nanoparticles were estimated by AAS and the attachments of coating to the nanoparticles were confirmed by FT-IR analysis. Physicochemical properties of nanoparticles were measured by DLS and zeta potential. Naked magnetite, chitosan and PVA coating have zeta potential of +36.4, +48.1 and -12.5 mV respectively. The unspecific adsorption and interaction between nanoparticles and bovine serum albumin (BSA) were investigated systematically by UV-vis spectroscopy method. The nanoparticles that were modified by PVA present low protein adsorption, which makes them a practical choice for preventing opsonization in clinical application and drug delivery. Copyright © 2015. Published by Elsevier B.V.

Impact of feed spacer and membrane modification by hydrophilic, bactericidal and biocidal coating on biofouling control

KAUST Repository

Araújo, Paula A.

2012-06-01

The influence of polydopamine- and polydopamine-. graft-poly(ethylene glycol)-coated feed spacers and membranes, copper-coated feed spacers, and commercially-available biostatic feed spacers on biofouling has been studied in membrane fouling simulators. Feed spacers and membranes applied in practical membrane filtration systems were used; biofouling development was monitored by feed channel pressure drop increase and biomass accumulation. Polydopamine and polydopamine-. g-PEG are hydrophilic surface modification agents expected to resist protein and bacterial adhesion, while copper feed spacer coatings and biocides infused in feed spacers are expected to restrict biological growth. Our studies showed that polydopamine and polydopamine-. g-PEG coatings on feed spacers and membranes, copper coatings on feed spacers, and a commercial biostatic feed spacer did not have a significant impact on feed channel pressure drop increase and biofilm accumulation as measured by ATP and TOC content. The studied spacer and membrane modifications were not effective for biofouling control; it is doubtful that feed spacer and membrane modification, in general, may be effective for biofouling control regardless of the type of applied coating. © 2012 Elsevier B.V.

Dehydration of an ethanol/water azeotrope by novel organic-inorganic hybrid membranes based on quaternized chitosan and tetraethoxysilane.

Science.gov (United States)

Uragami, Tadashi; Katayama, Takuya; Miyata, Takashi; Tamura, Hiroshi; Shiraiwa, Tadashi; Higuchi, Akon

2004-01-01

To control swelling of quaternized chitosan (q-Chito) membranes, mixtures of q-Chito as an organic component and tetraethoxysilane (TEOS) as an inorganic component were prepared using the sol-gel reaction, and novel q-Chito/TEOS hybrid membranes were formed. In the separation of an ethanol/water azeotrope by pervaporation, the effect of TEOS content on the water/ethanol selectivity of q-Chito/TEOS hybrid membranes was investigated. Hybrid membranes containing up to 45 mol % TEOS exhibited higher water/ethanol selectivity than the q-Chito membrane. This resulted from depressed swelling of the membranes by formation of a cross-linked structure. However, introduction of excess TEOS led to greater swelling of the hybrid membranes. Therefore, the water/ethanol selectivity of the hybrid membranes containing more than 45 mol % TEOS was lower than that of the q-Chito membrane. The relationship between the structure of q-Chito/TEOS hybrid membranes and their permeation and separation characteristics during pervaporation of an ethanol/water azeotrope is discussed in detail.

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

Science.gov (United States)

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-NLCcoated NLCs penetrated through the whole corneal epithelium barrier (about 40μm), while CMCS failed to significantly enhance the intraocular drug penetration as expected, displayed a negligible fluorescence at 30μm deep. In addition, penetration through the intact cornea was achieved and the penetration levels through the ocular tissues were increased thoroughly for the COS and CS-NAC coating ones compared with CMCS-NLC (P<0.05), and successfully reduced the conjunctival-to-corneal permeability ratio (ratio (C - S/C) ) thus resulted in a higher bioavailability, which was confirmed by ex vivo fluorescence imaging on ocular tissues. In summary, CS-NAC-NLC and COS-NLC are promising ocular drug delivery systems to achieve prolonged precorneal retention, higher corneal permeability and enhanced ocular bioavailability. And comparatively speaking, CS-NAC-NLC possesses the highest potential for ocular drug delivery. Copyright © 2017. Published by Elsevier B.V.

A strong adjuvant based on glycol-chitosan-coated lipid-polymer hybrid nanoparticles potentiates mucosal immune responses against the recombinant Chlamydia trachomatis fusion antigen CTH522.

Science.gov (United States)

Rose, Fabrice; Wern, Jeanette Erbo; Gavins, Francesca; Andersen, Peter; Follmann, Frank; Foged, Camilla

2018-02-10

Induction of mucosal immunity with vaccines is attractive for the immunological protection against pathogen entry directly at the site of infection. An example is infection with Chlamydia trachomatis (Ct), which is the most common sexually transmitted infection in the world, and there is an unmet medical need for an effective vaccine. A vaccine against Ct should elicit protective humoral and cell-mediated immune (CMI) responses in the genital tract mucosa. We previously designed an antibody- and CMI-inducing adjuvant based on poly(dl-lactic-co-glycolic acid) (PLGA) nanoparticles modified with the cationic surfactant dimethyldioctadecylammonium bromide and the immunopotentiator trehalose-6,6'-dibehenate. Here we show that immunization with these lipid-polymer hybrid nanoparticles (LPNs) coated with the mucoadhesive polymer chitosan enhances mucosal immune responses. Glycol chitosan (GC)-modified LPNs were engineered using an oil-in-water single emulsion solvent evaporation method. The nanoparticle design was optimized in a highly systematic way by using a quality-by-design approach to define the optimal operating space and to gain maximal mechanistic information about the GC coating of the LPNs. Cryo-transmission electron microscopy revealed a PLGA core coated with one or several concentric lipid bilayers. The GC coating of the surface was identified as a saturable, GC concentration-dependent increase in particle size and a reduction of the zeta-potential, and the coating layer could be compressed upon addition of salt. Increased antigen-specific mucosal immune responses were induced in the lungs and the genital tract with the optimized GC-coated LPN adjuvant upon nasal immunization of mice with the recombinant Ct fusion antigen CTH522. The mucosal responses were characterized by CTH522-specific IgG/IgA antibodies, together with CTH522-specific interferon γ-producing Th1 cells. This study demonstrates that mucosal administration of CTH522 adjuvanted with chitosan-coated

Chitosan-coated doxorubicin nano-particles drug delivery system inhibits cell growth of liver cancer via p53/PRC1 pathway.

Science.gov (United States)

Ye, Bai-Liang; Zheng, Ru; Ruan, Xiao-Jiao; Zheng, Zhi-Hai; Cai, Hua-Jie

2018-01-01

Nano-particles have been widely used in target-specific drug delivery system and showed advantages in cancers treatment. This study aims to evaluate the effect of chitosan coated doxorubicin nano-particles drug delivery system in liver cancer. The chitosan nano-particles were prepared by using the ionic gelation method. The characterizations of the nano-particles were determined by transmission electron microscopy. The cytotoxicity was detected by MTT assay, and the endocytosis, cell apoptosis and cell cycle were examined by flow cytometry. The protein level was analyzed with western blot. The dual luciferase reporter assay was performed to assess the interaction between p53 and the promoter of PRC1, and chromatin immune-precipitation was used to verify the binding between them. The FA-CS-DOX nano-particles were irregular and spherical particles around 30-40 nm, with uniform size and no adhesion. No significant difference was noted in doxorubicin release rate between CS-DOX and FA-CS-DOX. FA-CS-DOX nano-particles showed stronger cytotoxicity than CS-DOX. FA-CS-DOX nano-particles promoted the apoptosis and arrested cell cycle at G2/M phase, and they up-regulated p53. FA-CS-DOX nano-particles inhibited cell survival through p53/PRC1 pathway. Chitosan-coated doxorubicin nano-particles drug delivery system inhibits cell growth of liver cancer by promoting apoptosis and arresting cell cycle at G2/M phase through p53/PRC1 pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

Microarc oxidized TiO2 based ceramic coatings combined with cefazolin sodium/chitosan composited drug film on porous titanium for biomedical applications.

Science.gov (United States)

Wei, Daqing; Zhou, Rui; cheng, Su; Feng, Wei; Li, Baoqiang; Wang, Yaming; Jia, Dechang; Zhou, Yu; Guo, Haifeng

2013-10-01

Porous titanium was prepared by pressureless sintering of titanium beads with diameters of 100, 200, 400 and 600 μm. The results indicated that the mechanical properties of porous titanium changed significantly with different bead diameters. Plastic deformations such as necking phenomenon and dimple structure were observed on the fracture surface of porous titanium sintered by beads with diameter of 100 μm. However, it was difficult to find this phenomenon on the porous titanium with a titanium bead diameter of 600 μm. The microarc oxidized coatings were deposited on its surface to improve the bioactivity of porous titanium. Furthermore, the cefazolin sodium/chitosan composited films were fabricated on the microarc oxidized coatings for overcoming the inflammation due to implantation, showing good slow-release ability by addition of chitosan. And the release kinetic process of cefazolin sodium in composited films could be possibly fitted by a polynomial model. Copyright © 2013 Elsevier B.V. All rights reserved.

Chitosan/banana peel powder nanocomposites for wound dressing application: Preparation and characterization

International Nuclear Information System (INIS)

Kamel, Nagwa A.; Abd El-messieh, Salwa L.; Saleh, Neveen M.

2017-01-01

Wound infection is a serious infection has been spread worldwide. In order to provide fast aid treatments for such infection, banana peels have been incorporated within chitosan as wound dressing. Banana was collected from Egyptian markets peeled and the dried peels were grounded to powder, Incorporated as nano fillers within chitosan matrix with different concentrations (0, 2, 5 and 10 wt%). Glycerol was added as plasticizer and crosslinker to the membranes. The banana peel powder (BPP) particle shape and size were determined using Transmission Electron Microscope (TEM), The homogeneity and distribution of BPP in the membranes were investigated through Scanning Electron Microscope (SEM). The interaction between BPP and chitosan was characterized by Fourier Transform Infrared (FTIR). The dielectric properties of chitosan and BPP-chitosan membranes studied via dielectric constant, dielectric loss and conductivity measurements over a frequency range 100 Hz up to 100 kHz. The curves relating ε″ and the applied frequency are broad enough reflecting more than one relaxation process. These processes may be attributed to the relaxation processes of the main chain and its related motions. The higher values of ε″ at low frequency range may be a combination of the losses due to the electrical conductivity and the interfacial polarization process called “Maxwell Wagner Sillers” effect. By increasing BPP content in the sample a pronounced shift towards lower frequency was noticed. This shift may be due to some sort of polymer/filler interaction which causes an increase in the relaxed units and consequently the relaxation time. The addition of BPP decreases the swelling degree of chitosan matrix. The antimicrobial properties of the membranes were done against Gram positive, Gram negative bacteria and yeast. The results showed that chitosan/BPP membranes have a synergistic action with the highest activity at 10 wt%. Moreover, Candida albicans was the most sensitive

Chitosan/banana peel powder nanocomposites for wound dressing application: Preparation and characterization

Energy Technology Data Exchange (ETDEWEB)

Kamel, Nagwa A., E-mail: Na.kamel@nrc.sci.eg [Microwave Physics and Dielectrics Department, National Research Centre, Dokki, Cairo (Egypt); Abd El-messieh, Salwa L. [Microwave Physics and Dielectrics Department, National Research Centre, Dokki, Cairo (Egypt); Saleh, Neveen M. [Microbiology Department, National Organization of Drug Control and Research, Giza (Egypt)

2017-03-01

Wound infection is a serious infection has been spread worldwide. In order to provide fast aid treatments for such infection, banana peels have been incorporated within chitosan as wound dressing. Banana was collected from Egyptian markets peeled and the dried peels were grounded to powder, Incorporated as nano fillers within chitosan matrix with different concentrations (0, 2, 5 and 10 wt%). Glycerol was added as plasticizer and crosslinker to the membranes. The banana peel powder (BPP) particle shape and size were determined using Transmission Electron Microscope (TEM), The homogeneity and distribution of BPP in the membranes were investigated through Scanning Electron Microscope (SEM). The interaction between BPP and chitosan was characterized by Fourier Transform Infrared (FTIR). The dielectric properties of chitosan and BPP-chitosan membranes studied via dielectric constant, dielectric loss and conductivity measurements over a frequency range 100 Hz up to 100 kHz. The curves relating ε″ and the applied frequency are broad enough reflecting more than one relaxation process. These processes may be attributed to the relaxation processes of the main chain and its related motions. The higher values of ε″ at low frequency range may be a combination of the losses due to the electrical conductivity and the interfacial polarization process called “Maxwell Wagner Sillers” effect. By increasing BPP content in the sample a pronounced shift towards lower frequency was noticed. This shift may be due to some sort of polymer/filler interaction which causes an increase in the relaxed units and consequently the relaxation time. The addition of BPP decreases the swelling degree of chitosan matrix. The antimicrobial properties of the membranes were done against Gram positive, Gram negative bacteria and yeast. The results showed that chitosan/BPP membranes have a synergistic action with the highest activity at 10 wt%. Moreover, Candida albicans was the most sensitive

Two-step preparation of nano-scaled magnetic chitosan particles using Triton X-100 reversed-phase water-in-oil microemulsion system

International Nuclear Information System (INIS)

Zhou, Zhengkun; Jiang, Feihong; Lee, Tung-Ching; Yue, Tianli

2013-01-01

Highlights: •A new two-step route for nano-scaled magnetic chitosan particles preparation. •Triton X-100 reversed-phase microemulsion system was used for chitosan coating. •Narrow size distribution of magnetic chitosan nanoparticles was achieved. •Quantitative evaluation of recoverability for the magnetic chitosan nanoparticles. -- Abstract: A new two-step route for the preparation of nano-scaled magnetic chitosan particles has been developed, different from reported one-step in situ preparation and two-step preparation method of reversed-phase suspension, Triton X-100 reversed-phase water-in-oil microemulsion encapsulation method was employed in coating the pre-prepared Fe 3 O 4 nanoparticles with chitosan. The resultant magnetic chitosan particles owned a narrow size distribution ranging from 50 to 92 nm. X-ray diffraction patterns (XRD) indicated that the chitosan coating procedure did not change the spinal structure of Fe 3 O 4 magnetic nanoparticles. The results of Fourier transform infrared (FTIR) analysis and thermogravimetric analysis (TGA) demonstrated that the chitosan was coated on Fe 3 O 4 nanoparticles and its average mass content was ∼50%. The saturated magnetization of the magnetic Fe 3 O 4 /chitosan nanoparticles reached 18.62 emu/g, meanwhile, the nanoparticles showed the characteristics of superparamagnetism. The magnetic chitosan nanoparticles showed a high recoverability of 99.99% in 10 min when pH exceeded 4. The results suggested that the as-prepared magnetic chitosan particles were nano-scaled with a narrow size distribution and a high recoverability

Detection of Cadmium Ion by Evanescent Wave Based Chitosan Coated Optical Fiber Sensor

International Nuclear Information System (INIS)

Yulianti, I; Edy, S S; Saputra, B A; Aji, M P; Susanto; Kurdi, O

2017-01-01

Evanescent wave based-optical fiber sensor to detect cadmium ion is proposed. Chitosan was used by using the dip-coating method. The sensor was fabricated in U-bent shape. U-bent optical sensor at aconcentration of 2ppm and 5ppm had asensitivity of 0.2067 dBm/ppm and -0.7995 dBm/ppm, respectively. At a level of 2ppm - 5ppm, the optical sensor has a linear response with asensitivity of -0.283 dBm/ppm. The sensor takes 9.5 minutes to reach steady stateat aconcentration of 1 ppm. Atalevel of 2ppm - 5ppm, the sensor takes 5 minutes to 10.45 minutes to reach steady state. (paper)

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.

Erythrocyte membrane-coated gold nanocages for targeted photothermal and chemical cancer therapy

Science.gov (United States)

Zhu, Dao-Ming; Xie, Wei; Xiao, Yu-Sha; Suo, Meng; Zan, Ming-Hui; Liao, Qing-Quan; Hu, Xue-Jia; Chen, Li-Ben; Chen, Bei; Wu, Wen-Tao; Ji, Li-Wei; Huang, Hui-Ming; Guo, Shi-Shang; Zhao, Xing-Zhong; Liu, Quan-Yan; Liu, Wei

2018-02-01

Recently, red blood cell (RBC) membrane-coated nanoparticles have attracted much attention because of their excellent immune escapability; meanwhile, gold nanocages (AuNs) have been extensively used for cancer therapy due to their photothermal effect and drug delivery capability. The combination of the RBC membrane coating and AuNs may provide an effective approach for targeted cancer therapy. However, few reports have shown the utilization of combining these two technologies. Here, we design erythrocyte membrane-coated gold nanocages for targeted photothermal and chemical cancer therapy. First, anti-EpCam antibodies were used to modify the RBC membranes to target 4T1 cancer cells. Second, the antitumor drug paclitaxel (PTX) was encapsulated into AuNs. Then, the AuNs were coated with the modified RBC membranes. These new nanoparticles were termed EpCam-RPAuNs. We characterized the capability of the EpCam-RPAuNs for selective tumor targeting via exposure to near-infrared irradiation. The experimental results demonstrate that EpCam-RPAuNs can effectively generate hyperthermia and precisely deliver the antitumor drug PTX to targeted cells. We also validated the biocompatibility of the EpCam-RAuNs in vitro. By combining the molecularly modified targeting RBC membrane and AuNs, our approach provides a new way to design biomimetic nanoparticles to enhance the surface functionality of nanoparticles. We believe that EpCam-RPAuNs can be potentially applied for cancer diagnoses and therapies.

Adhesive coatings based on melanin-like nanoparticles for surgical membranes.

Science.gov (United States)

Scognamiglio, Francesca; Travan, Andrea; Turco, Gianluca; Borgogna, Massimiliano; Marsich, Eleonora; Pasqua, Mattia; Paoletti, Sergio; Donati, Ivan

2017-07-01

Adhesive coatings for implantable biomaterials can be designed to prevent material displacement from the site of implant. In this paper, a strategy based on the use of melanin-like nanoparticles (MNPs) for the development of adhesive coatings for polysaccharidic membranes was devised. MNPs were synthesized in vitro and characterized in terms of dimensions and surface potential, as a function of pH and ionic strength. The in vitro biocompatibility of MNPs was investigated on fibroblast cells, while the antimicrobial properties of MNPs in suspension were evaluated on E. coli and S. aureus cultures. The manufacturing of the adhesive coatings was carried out by spreading MNPs over the surface of polysaccharidic membranes; the adhesive properties of the nano-engineered coating to the target tissue (intestinal serosa) were studied in simulated physiological conditions. Overall, this study opens for novel approaches in the design of naturally inspired nanostructured adhesive systems. Copyright © 2017 Elsevier B.V. All rights reserved.

Development of a chitosan based double layer-coated tablet as a platform for colon-specific drug delivery

Directory of Open Access Journals (Sweden)

Kim MS

2016-12-01

Full Text Available Min Soo Kim,1,* Dong Woo Yeom,1,* Sung Rae Kim,1 Ho Yub Yoon,1 Chang Hyun Kim,1 Ho Yong Son,1 Jin Han Kim,1 Sangkil Lee,2 Young Wook Choi1 1College of Pharmacy, Chung-Ang University, Seoul, 2College of Pharmacy, Keimyung University, Daegu, South Korea *These authors contributed equally to this work Abstract: A double layer-coated colon-specific drug delivery system (DL-CDDS was developed, which consisted of chitosan (CTN based polymeric subcoating of the core tablet containing citric acid for microclimate acidification, followed by an enteric coating. The polymeric composition ratio of Eudragit E100 and ethyl cellulose and amount of subcoating were optimized using a two-level factorial design method. Drug-release characteristics in terms of dissolution efficiency and controlled-release duration were evaluated in various dissolution media, such as simulated colonic fluid in the presence or absence of CTNase. Microflora activation and a stepwise mechanism for drug release were postulated. Consequently, the optimized DL-CDDS showed drug release in a controlled manner by inhibiting drug release in the stomach and intestine, but releasing the drug gradually in the colon (approximately 40% at 10 hours and 92% at 24 hours in CTNase-supplemented simulated colonic fluid, indicating its feasibility as a novel platform for CDD. Keywords: chitosan, colon-specific delivery, acidification, microflora, factorial design, controlled release

Chitosan-based water-propelled micromotors with strong antibacterial activity.

Science.gov (United States)

Delezuk, Jorge A M; Ramírez-Herrera, Doris E; Esteban-Fernández de Ávila, Berta; Wang, Joseph

2017-02-09

A rapid and efficient micromotor-based bacteria killing strategy is described. The new antibacterial approach couples the attractive antibacterial properties of chitosan with the efficient water-powered propulsion of magnesium (Mg) micromotors. These Janus micromotors consist of Mg microparticles coated with the biodegradable and biocompatible polymers poly(lactic-co-glycolic acid) (PLGA), alginate (Alg) and chitosan (Chi), with the latter responsible for the antibacterial properties of the micromotor. The distinct speed and efficiency advantages of the new micromotor-based environmentally friendly antibacterial approach have been demonstrated in various control experiments by treating drinking water contaminated with model Escherichia coli (E. coli) bacteria. The new dynamic antibacterial strategy offers dramatic improvements in the antibacterial efficiency, compared to static chitosan-coated microparticles (e.g., 27-fold enhancement), with a 96% killing efficiency within 10 min. Potential real-life applications of these chitosan-based micromotors for environmental remediation have been demonstrated by the efficient treatment of seawater and fresh water samples contaminated with unknown bacteria. Coupling the efficient water-driven propulsion of such biodegradable and biocompatible micromotors with the antibacterial properties of chitosan holds great considerable promise for advanced antimicrobial water treatment operation.

Properties and in vitro biological evaluation of nano-hydroxyapatite/chitosan membranes for bone guided regeneration

Energy Technology Data Exchange (ETDEWEB)

Cheng Xianmiao [Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, 610064 Chengdu (China); Department of Chemistry, Sichuan University, 610064 Chengdu (China); Li Yubao [Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, 610064 Chengdu (China)], E-mail: nic7504@scu.edu.cn; Zuo Yi; Zhang Li [Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, 610064 Chengdu (China); Li Jidong [Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, 610064 Chengdu (China); Department of Chemistry, Sichuan University, 610064 Chengdu (China); Wang Huanan [Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, 610064 Chengdu (China)

2009-01-01

Nano-hydroxyapatite(n-HA)/chitosan(CS) composite membranes were prepared by solvent casting and evaporation methods for the function of guided bone regeneration (GBR). The effect of n-HA content and solvent evaporation temperature on the properties of the composite membranes was studied. The n-HA/CS membranes were analyzed by scanning electron microscopy, Fourier transformed infrared spectroscopy, X-ray diffraction, swelling measurement, mechanical test, cell culture and MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenylte-2H-tetrazolium bromide) assay. The results show that the surface roughness and micropores of the composite membranes increase with the rise of n-HA content, suitable for adhesion, crawl and growth of cells. The hydroxyapatite holds nano size and distributes uniformly in the composite membranes. Chemical bond interaction exists between Ca ions and -OH groups of n-HA and -NH{sub 2} or -OH groups of CS. The n-HA content and solvent evaporation temperature have obvious influence on the swelling ratio, tensile strength and elongation rate of the composite membranes. Cell culture and MTT assays show that n-HA and its content can affect the proliferation of cells. The n-HA/CS composite membranes have no negative effect on the cell morphology, viability and proliferation and possess good biocompatibility. This study makes the n-HA/CS composite membrane be a prospective biodegradable GBR membrane for future applications.

Properties and in vitro biological evaluation of nano-hydroxyapatite/chitosan membranes for bone guided regeneration

International Nuclear Information System (INIS)

Cheng Xianmiao; Li Yubao; Zuo Yi; Zhang Li; Li Jidong; Wang Huanan

2009-01-01

Nano-hydroxyapatite(n-HA)/chitosan(CS) composite membranes were prepared by solvent casting and evaporation methods for the function of guided bone regeneration (GBR). The effect of n-HA content and solvent evaporation temperature on the properties of the composite membranes was studied. The n-HA/CS membranes were analyzed by scanning electron microscopy, Fourier transformed infrared spectroscopy, X-ray diffraction, swelling measurement, mechanical test, cell culture and MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenylte-2H-tetrazolium bromide) assay. The results show that the surface roughness and micropores of the composite membranes increase with the rise of n-HA content, suitable for adhesion, crawl and growth of cells. The hydroxyapatite holds nano size and distributes uniformly in the composite membranes. Chemical bond interaction exists between Ca ions and -OH groups of n-HA and -NH 2 or -OH groups of CS. The n-HA content and solvent evaporation temperature have obvious influence on the swelling ratio, tensile strength and elongation rate of the composite membranes. Cell culture and MTT assays show that n-HA and its content can affect the proliferation of cells. The n-HA/CS composite membranes have no negative effect on the cell morphology, viability and proliferation and possess good biocompatibility. This study makes the n-HA/CS composite membrane be a prospective biodegradable GBR membrane for future applications

Two-step preparation of nano-scaled magnetic chitosan particles using Triton X-100 reversed-phase water-in-oil microemulsion system

Energy Technology Data Exchange (ETDEWEB)

Zhou, Zhengkun; Jiang, Feihong [College of Food Science and Engineering, Northwest A and F University, Yangling, Shaanxi 712100 (China); Lee, Tung-Ching, E-mail: lee@aesop.rutgers.edu [Department of Food Science, Rutgers, the State University of New Jersey, 65 Dudley Road, New Brunswick, NJ 08901 (United States); Yue, Tianli, E-mail: yuetl305@nwsuaf.edu.cn [College of Food Science and Engineering, Northwest A and F University, Yangling, Shaanxi 712100 (China)

2013-12-25

Highlights: •A new two-step route for nano-scaled magnetic chitosan particles preparation. •Triton X-100 reversed-phase microemulsion system was used for chitosan coating. •Narrow size distribution of magnetic chitosan nanoparticles was achieved. •Quantitative evaluation of recoverability for the magnetic chitosan nanoparticles. -- Abstract: A new two-step route for the preparation of nano-scaled magnetic chitosan particles has been developed, different from reported one-step in situ preparation and two-step preparation method of reversed-phase suspension, Triton X-100 reversed-phase water-in-oil microemulsion encapsulation method was employed in coating the pre-prepared Fe{sub 3}O{sub 4} nanoparticles with chitosan. The resultant magnetic chitosan particles owned a narrow size distribution ranging from 50 to 92 nm. X-ray diffraction patterns (XRD) indicated that the chitosan coating procedure did not change the spinal structure of Fe{sub 3}O{sub 4} magnetic nanoparticles. The results of Fourier transform infrared (FTIR) analysis and thermogravimetric analysis (TGA) demonstrated that the chitosan was coated on Fe{sub 3}O{sub 4} nanoparticles and its average mass content was ∼50%. The saturated magnetization of the magnetic Fe{sub 3}O{sub 4}/chitosan nanoparticles reached 18.62 emu/g, meanwhile, the nanoparticles showed the characteristics of superparamagnetism. The magnetic chitosan nanoparticles showed a high recoverability of 99.99% in 10 min when pH exceeded 4. The results suggested that the as-prepared magnetic chitosan particles were nano-scaled with a narrow size distribution and a high recoverability.

Hydroxypropyltrimethyl Ammonium Chloride Chitosan Functionalized-PLGA Electrospun Fibrous Membranes as Antibacterial Wound Dressing: In Vitro and In Vivo Evaluation

Directory of Open Access Journals (Sweden)

Shengbing Yang

2017-12-01

Full Text Available A novel poly(lactic-co-glycolic acid (PLGA-hydroxypropyltrimethyl ammonium chloride chitosan (HACC composite nanofiber wound dressing was prepared through electrospinning and the entrapment-graft technique as an antibacterial dressing for cutaneous wound healing. HACC with 30% degrees of substitution (DS was immobilized onto the surface of PLGA membranes via the reaction between carboxyl groups in PLGA after alkali treatment and the reactive groups (–NH2 in HACC molecules. The naked PLGA and chitosan graft PLGA (PLGA-CS membranes served as controls. The surface immobilization was characterized by scanning electron microscopy (SEM, atomic force microscopy (AFM, Fourier transform infrared (FTIR, thermogravimetric analysis (TGA and energy dispersive X-ray spectrometry (EDX. The morphology studies showed that the membranes remain uniform after the immobilization process. The effects of the surface modification by HACC and CS on the biological properties of the membranes were also investigated. Compared with PLGA and PLGA-CS, PLGA-HACC exhibited more effective antibacterial activity towards both Gram-positive (S. aureus and Gram-negative (P. aeruginosa bacteria. The newly developed fibrous membranes were evaluated in vitro for their cytotoxicity using human dermal fibroblasts (HDFs and human keratinocytes (HaCaTs and in vivo using a wound healing mice model. It was revealed that PLGA-HACC fibrous membranes exhibited favorable cytocompatibility and significantly stimulated adhesion, spreading and proliferation of HDFs and HaCaTs. PLGA-HACC exhibited excellent wound healing efficacy, which was confirmed using a full thickness excision wound model in S. aureus-infected mice. The experimental results in this work suggest that PLGA-HACC is a strong candidate for use as a therapeutic biomaterial in the treatment of infected wounds.

Basic study of healing of injuries to the myometrium and amniotic membrane using photocrosslinkable chitosan.

Science.gov (United States)

Suzuki, Keitaro; Shinya, Masaru; Kitagawa, Michihiro

2006-04-01

We performed in vivo and in vitro adhesion experiments on the use of photocrosslinkable chitosan (PC) for healing of the myometrium and the amniotic membrane to test its usefulness in the perinatal field. To determine the adhesion conditions of PC in the healing of the myometrium and amniotic membrane, we applied two concentrations (30 and 50 mg/mL) of PC to the postpartum amniotic membrane, and radiated it with ultraviolet (UV) light for 10, 20, 30 or 60 s. Next, we created incisions of three sizes (pinhole, 5 mm and 10 mm), and performed PC adhesion followed by pressure application experiments. Subsequently, we laparotomized 12-day-pregnant rats under anesthesia, created a 5-mm incision, applied PC and closed the abdomen. We removed the uterus at 20 days of pregnancy, and histologically examined the site of PC application. The optimal adhesion conditions of PC were 50 mg/mL, and the optimal time of UV irradiation was 30 s or longer. In pressure application experiments, the bonding strength of PC was so high that even 10-mm incisions withstood a mean pressure of 92 mmH2O. The bonding strength of PC was significantly higher than that of fibrin glue that was tested in parallel. Histological examination of the rat myometrium showed a mild foreign body reaction with no inflammatory findings, confirming the usefulness of PC. PC is a wound-healing drug, an improvement on the naturally occurring polysaccharide chitosan, and is safer and has a higher bonding strength than biological adhesives including fibrin, making it promising for fetal surgical and perinatal applications.

Systems and methods for using a boehmite bond-coat with polyimide membranes for gas separation

Science.gov (United States)

Polishchuk, Kimberly Ann

2013-03-05

The subject matter disclosed herein relates to gas separation membranes and, more specifically, to polyimide gas separation membranes. In an embodiment, a gas separation membrane includes a porous substrate, a substantially continuous polyimide membrane layer, and one or more layers of boehmite nanoparticles disposed between the porous substrate and the polyimide membrane layer to form a bond-coat layer. The bond-coat layer is configured to improve the adhesion of the polyimide membrane layer to the porous substrate, and the polyimide membrane layer has a thickness approximately 100 nm or less.

Structural coloration of chitosan-cationized cotton fabric using photonic crystals

OpenAIRE

Yavuz, Gonul; Zille, Andrea; Seventekin, N.; Souto, A. Pedro

2017-01-01

Abstract. 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 fab...

Smart coating process of proton-exchange membrane for polymer electrolyte fuel cell

International Nuclear Information System (INIS)

Leu, Hoang-Jyh; Chiu, Kuo-Feng; Lin, Chiu-Yue

2013-01-01

Highlights: ► Using oxygen plasma and smart coating technique for membrane modification. ► Oxygen plasma treatment can increase the reaction area of the membrane. ► AFM, SEM, FT-IR, XPS, EIS spectra can prove the surface treatment process. ► Nafion membrane modification can reduce Rct and enhance current density. - Abstract: The interfaces of electrolyte|catalyst|electrode play an important role in the performance of proton-exchange membrane fuel cells (PEMFCs). Increasing the interface effective area and lowering the charge transfer resistance of the interface are significant issues to promote the cell performance. In this study, oxygen plasma treatment was used to increase the surface roughness of Nafion®117 membrane, and then a smart coating process was applied to fabricate the initial Pt/C catalyst layer, which served to reduce the charge transfer resistance of the interface. The morphology and surface characteristics of membranes have been qualified by scanning electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy. These results show that the plasma treatments and smart coating processes were effective in reducing the interface charge transfer resistance. At optimal condition, the interface charge transfer resistance was 0.45 Ω/cm 2 which was 1–2 order less than the untreated ones

Integrated antibacterial and antifouling surfaces via cross-linking chitosan-g-eugenol/zwitterionic copolymer on electrospun membranes.

Science.gov (United States)

Li, Zhenguang; Hu, Wenhong; Zhao, Yunhui; Ren, Lixia; Yuan, Xiaoyan

2018-04-27

Integrated antibacterial and antifouling surfaces in favor of avoiding implant-related infections are necessarily required for biomaterials when they contact with the body fluid. In this work, an antibacterial and antifouling membrane was developed via cross-linking chitosan-g-eugenol and the zwitterionic copolymer poly(sulfobetaine methylacrylate-co-2-aminoethyl methacrylate) on the electrospun polycarbonate urethane substrate using genipin as a cross-linker. Antibacterial assays demonstrated that the prepared membranes had efficient antibacterial activity with 92.8 ± 2.5% and 95.2 ± 1.3% growth inhibition rates against Escherichia coli and Staphylococcus aureus, respectively. The investigations on antifouling activity and hemocompatibility of the membranes showed significant resistances to bacterial attachment, non-specific protein adsorption and platelet adhesion, and presented lower hemolytic activity and good anticoagulant activity as well. Moreover, cell culture assays indicated that the prepared membranes exerted no obvious cytotoxicity with more than 80% of relative L929 fibroblast viability. Therefore, the membranes with integrated antibacterial and antifouling properties could be potentially applied in promising indwelling devices. Copyright © 2018 Elsevier B.V. All rights reserved.

Antibacterial polylactic acid/chitosan nanofibers decorated with bioactive glass

Energy Technology Data Exchange (ETDEWEB)

Goh, Yi-fan; Akram, Muhammad; Alshemary, Ammarz [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Hussain, Rafaqat, E-mail: rafaqat@comsats.edu.pk [Department of Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan)

2016-11-30

Highlights: • PLA/Chitosan nanofibers were coated with functional bioglass. • Polymer/ceramic composite fibers exhibited good in-vitro bioactivity. • Nanofibers coated with Ag doped bioglass exhibited good antibacterial activity. - Abstract: In this study, we have presented the structural and in vitro characterization of electrospun polylactic acid (PLA)/Chitosan nanofibers coated with cerium, copper or silver doped bioactive glasses (CeBG/CuBG/AgBG). Bead-free, smooth surfaced nanofibers were successfully prepared by using electrospinning technique. The nanocomposite fibers were obtained using a facile dip-coating method, their antibacterial activities against E. coliE. coli (ATCC 25922 strains) were measured by the disk diffusion method after 24 h of incubation at 37 °C. CeBG and CuBG decorated PLA/Chitosan nanofibers did not develop an inhibition zone against the bacteria. On the other hand, nanofibers coated with AgBG developed an inhibition zone against the bacteria. The as-prepared nanocomposite fibers were immersed in SBF for 1, 3 and 7 days in Simulated Body Fluid (SBF) for evaluation of in vitro bioactivity. All samples induced the formation of crystallites with roughly ruffled morphology and the pores of fibers were covered with the extensive growth of crystallites. Energy Dispersive X-ray (EDX) composition analysis showed that the crystallites possessed Ca/P ratio close to 1.67, confirming the good in-vitro bioactivity of the fibers.

Preparation and evaluation of PEGylated phospholipid membrane coated layered double hydroxide nanoparticles

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Mina Yan

2016-06-01

Full Text Available The aim of the present study was to develop layered double hydroxide (LDH nanoparticles coated with PEGylated phospholipid membrane. By comparing the size distribution and zeta potential, the weight ratio of LDH to lipid materials which constitute the outside membrane was identified as 2:1. Transmission electron microscopy photographs confirmed the core-shell structure of PEGylated phospholipid membrane coated LDH (PEG-PLDH nanoparticles, and cell cytotoxicity assay showed their good cell viability on Hela and BALB/C-3T3 cells over the concentration range from 0.5 to 50 μg/mL.

Influence of molecular weight and pH on adsorption of chitosan at the surface of large and giant vesicles.

Science.gov (United States)

Quemeneur, Francois; Rinaudo, Marguerite; Pépin-Donat, Brigitte

2008-01-01

This paper describes the mechanisms of adsorption of chitosan, a positively charged polyelectrolyte, on the DOPC lipid membrane of large and giant unilamellar vesicles (respectively, LUVs and GUVs). We observe that the variation of the zeta potential of LUVs as a function of chitosan concentration is independent on the chitosan molecular weight (Mw). This result is interpreted in terms of electrostatic interactions, which induce a flat adsorption of the chitosan on the surface of the membrane. The role of electrostatic interactions is further studied by observing the variation of the zeta potential as a function of the chitosan concentration for two different charge densities tuned by the pH. Results show a stronger chitosan-membrane affinity at pH 6 (lipids are negatively charged, and 40% chitosan amino groups are protonated) than at pH 3.4 (100% of protonated amino groups but zwitterionic lipids are positively charged) which confirms that adsorption is of electrostatic origin. Then, we investigate the stability of decorated LUVs and GUVs in a large range of pH (6.0 pH variation of the zeta potential as a function of the pH (2.0 pH pH pH > 10.0, in the absence of chitosan, the vesicles present complex shapes, contrary to the chitosan-decorated vesicles which remain spherical, confirming thus that chitosan remains adsorbed on vesicles in basic conditions up to pH = 12.0. These results, in addition with our previous data, show that the chitosan-decorated vesicles are stable over a very broad range of pH (2.0 pH < 12.0), which holds promise for their in vivo applications. Finally, the quantification of the chitosan adsorption on a LUV membrane is performed by zeta potential and fluorescence measurements. The fraction of membrane surface covered by chitosan is estimated to be lower than 40 %, which corresponds to the formation of a flat layer of chitosan on the membrane surface on an electrostatic basis.

In-Vitro Enzymatic Degradation of γ-irradiated Porous Chitosan Scaffold: Crystallinity and degree of deacetylation

International Nuclear Information System (INIS)

Ismail Zainol; Azreena Mastor; Suhaida Md Ghani; Ahmad Fuad Yahya; Hazizan Md Akil

2009-01-01

Full text: Enzymatic degradation behavior of porous chitosan membrane was carried out in vitro by using enzymatic hydrolysis of chitosan in lysozyme solution. Chitosan was first modified by reducing its molecular weight by gamma (γ) radiation in the solid state. The chitosan powder was irradiated with gamma Co 60 source with various doses of 10, 25, 50 and 100 kGy. The molecular weight of irradiated chitosan was measured using visco metric method. The modified chitosan was transform into a porous membrane by lyophilization method. Degree of deacetylation (DD) and crystallinity of samples were measured using FTIR and XRD respectively on both gamma irradiated and enzymatic degradation samples. The results suggested that the irradiated chitosan become less crystalline without changes in DD. The enzymatic degradation of chitosan however shows an increment in DD and crystallinity. (author)

Growth and morphogenesis of embryonic mouse organs on non-coated and extracellular matrix-coated Biopore membrane

Science.gov (United States)

Hardman, P.; Klement, B. J.; Spooner, B. S.

1993-01-01

Embryonic mouse salivary glands, pancreata, and kidneys were isolated from embryos of appropriate gestational age by microdissection, and were cultured on Biopore membrane either non-coated or coated with type I collagen or Matrigel. As expected, use of Biopore membrane allowed high quality photomicroscopy of the living organs. In all organs extensive mesenchymal spreading was observed in the presence of type I collagen or Matrigel. However, differences were noted in the effects of extracellular matrix (ECM) coatings on epithelial growth and morphogenesis: salivary glands were minimally affected, pancreas morphogenesis was adversely affected, and kidney growth and branching apparently was enhanced. It is suggested that these differences in behaviour reflect differences in the strength of interactions between the mesenchymal cells and their surrounding endogenous matrix, compared to the exogenous ECM macromolecules. This method will be useful for culture of these and other embryonic organs. In particular, culture of kidney rudiments on ECM-coated Biopore offers a great improvement over previously used methods which do not allow morphogenesis to be followed in vitro.

Action of Chitosan Against Xanthomonas Pathogenic Bacteria Isolated from Euphorbia pulcherrima

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Yanli Wang

2012-06-01

Full Text Available The antibacterial activity and mechanism of two kinds of chitosan were investigated against twelve Xanthomonas strains recovered from Euphorbia pulcherrima. Results indicated that both chitosans markedly inhibited bacterial growth based on OD loss. Furthermore, the release of DNA and RNA from three selected strains was increased by both chitosans. However, the release of intracellular proteins was inhibited by both chitosans at different concentration and incubation times, except chitosan A at 0.1 mg/mL for 0.5 h incubation and 0.2 mg/mL for 2.0 h incubation increased the release of proteins, indicating the complexity of the interaction and cell membranes, which was affected by incubation time, bacterial species, chitosan type and concentration. Transmission electron microscopic observations revealed that chitosan caused changes in protoplast concentration and surface morphology. In some cells, the membranes and walls were badly distorted and disrupted, while other cells were enveloped by a thick and compact ribbon-like layer. The contrary influence on cell morphology may explain the differential effect in the release of material. In addition, scanning electron microscope and biofilm formation test revealed that both chitosans removed biofilm biomass. Overall, this study showed that membrane and biofilm play an important role in the antibacterial mechanism of chitosan.

In vitro osteoclastogenesis on textile chitosan scaffold

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C Heinemann

2010-02-01

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

Chitosan modified poly(lactic-co-glycolic acid nanoparticles interaction with normal, precancerous keratinocytes and dental pulp cells

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Maria Justina Roxana Virlan

2017-03-01

Conclusion: Chitosan-coated PLGAChi NPs proved to be able to cross the cellular membrane of oral keratinocytes, in 2D as well as in 3D cultures. The polymeric NPs used in the present study seem not to be suitable for applications that require NPs uptake by DPCs, as no evidence of uptake in these cells was found in this study. The finding that PLGAChi NPs showed significant internalization by human keratinocytes indicate that they could be used for drug delivery purposes to oral mucosa.

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)

Chitosan/banana peel powder nanocomposites for wound dressing application: Preparation and characterization.

Science.gov (United States)

Kamel, Nagwa A; Abd El-Messieh, Salwa L; Saleh, Neveen M

2017-03-01

Wound infection is a serious infection has been spread worldwide. In order to provide fast aid treatments for such infection, banana peels have been incorporated within chitosan as wound dressing. Banana was collected from Egyptian markets peeled and the dried peels were grounded to powder, Incorporated as nano fillers within chitosan matrix with different concentrations (0, 2, 5 and 10wt%). Glycerol was added as plasticizer and crosslinker to the membranes. The banana peel powder (BPP) particle shape and size were determined using Transmission Electron Microscope (TEM), The homogeneity and distribution of BPP in the membranes were investigated through Scanning Electron Microscope (SEM). The interaction between BPP and chitosan was characterized by Fourier Transform Infrared (FTIR). The dielectric properties of chitosan and BPP-chitosan membranes studied via dielectric constant, dielectric loss and conductivity measurements over a frequency range 100Hz up to 100kHz. The curves relating ε″ and the applied frequency are broad enough reflecting more than one relaxation process. These processes may be attributed to the relaxation processes of the main chain and its related motions. The higher values of ε″ at low frequency range may be a combination of the losses due to the electrical conductivity and the interfacial polarization process called "Maxwell Wagner Sillers" effect. By increasing BPP content in the sample a pronounced shift towards lower frequency was noticed. This shift may be due to some sort of polymer/filler interaction which causes an increase in the relaxed units and consequently the relaxation time. The addition of BPP decreases the swelling degree of chitosan matrix. The antimicrobial properties of the membranes were done against Gram positive, Gram negative bacteria and yeast. The results showed that chitosan/BPP membranes have a synergistic action with the highest activity at 10wt%. Moreover, Candida albicans was the most sensitive strain

Model-Based Control of a Continuous Coating Line for Proton Exchange Membrane Fuel Cell Electrode Assembly

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Vikram Devaraj

2015-01-01

Full Text Available The most expensive component of a fuel cell is the membrane electrode assembly (MEA, which consists of an ionomer membrane coated with catalyst material. Best-performing MEAs are currently fabricated by depositing and drying liquid catalyst ink on the membrane; however, this process is limited to individual preparation by hand due to the membrane’s rapid water absorption that leads to shape deformation and coating defects. A continuous coating line can reduce the cost and time needed to fabricate the MEA, incentivizing the commercialization and widespread adoption of fuel cells. A pilot-scale membrane coating line was designed for such a task and is described in this paper. Accurate process control is necessary to prevent manufacturing defects from occurring in the coating line. A linear-quadratic-Gaussian (LQG controller was developed based on a physics-based model of the coating process to optimally control the temperature and humidity of the drying zones. The process controller was implemented in the pilot-scale coating line proving effective in preventing defects.

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

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

Influence of plasma modification on hygienic properties of textile fabrics with nonporous membrane coating

Science.gov (United States)

Voznesensky, E. F.; Ibragimov, R. G.; Vishnevskaya, O. V.; Sisoev, V. A.; Lutfullina, G. G.; Tihonova, N. V.

2017-11-01

The work investigated the possibility of using plasma modification to improve the hygienic properties of textile materials with nonporous membrane coating to improve vapor-, air-permeability and water-resistant. Determined that, after plasma modification changes degree of supramolecular orderliness of the polymers nonporous membrane coating and the base fabric.

Membrane Distillation of Meat Industry Effluent with Hydrophilic Polyurethane Coated Polytetrafluoroethylene Membranes

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M. G. Mostafa

2017-09-01

Full Text Available Meat rendering operations produce stick water waste which is rich in proteins, fats, and minerals. Membrane distillation (MD may further recover water and valuable solids, but hydrophobic membranes are contaminated by the fats. Here, commercial hydrophobic polytetrafluorethylene (PTFE membranes with a hydrophilic polyurethane surface layer (PU-PTFE are used for the first time for direct contact MD (DCMD on real poultry, fish, and bovine stick waters. Metal membrane microfiltration (MMF was also used to capture fats prior to MD. Although the standard hydrophobic PTFE membranes failed rapidly, PU-PTFE membranes effectively processed all stick water samples to colourless permeate with sodium rejections >99%. Initial clean solution fluxes 5–6 L/m2/h declined to less than half during short 40% water recovery tests for all stick water samples. Fish stick water uniquely showed reduced fouling and up to 78% water recovery. Lost flux was easily restored by rinsing the membrane with clean water. MMF prior to MD removed 92% of fats, facilitating superior MD performance. Differences in fouling between stick waters were attributed to temperature polarisation from higher melt temperature fats and relative proportions to proteins. Hydrophilic coated MD membranes are applicable to stick water processing but further studies should consider membrane cleaning and longer-term stability.

Membrane Distillation of Meat Industry Effluent with Hydrophilic Polyurethane Coated Polytetrafluoroethylene Membranes.

Science.gov (United States)

Mostafa, M G; Zhu, Bo; Cran, Marlene; Dow, Noel; Milne, Nicholas; Desai, Dilip; Duke, Mikel

2017-09-29

Meat rendering operations produce stick water waste which is rich in proteins, fats, and minerals. Membrane distillation (MD) may further recover water and valuable solids, but hydrophobic membranes are contaminated by the fats. Here, commercial hydrophobic polytetrafluorethylene (PTFE) membranes with a hydrophilic polyurethane surface layer (PU-PTFE) are used for the first time for direct contact MD (DCMD) on real poultry, fish, and bovine stick waters. Metal membrane microfiltration (MMF) was also used to capture fats prior to MD. Although the standard hydrophobic PTFE membranes failed rapidly, PU-PTFE membranes effectively processed all stick water samples to colourless permeate with sodium rejections >99%. Initial clean solution fluxes 5-6 L/m²/h declined to less than half during short 40% water recovery tests for all stick water samples. Fish stick water uniquely showed reduced fouling and up to 78% water recovery. Lost flux was easily restored by rinsing the membrane with clean water. MMF prior to MD removed 92% of fats, facilitating superior MD performance. Differences in fouling between stick waters were attributed to temperature polarisation from higher melt temperature fats and relative proportions to proteins. Hydrophilic coated MD membranes are applicable to stick water processing but further studies should consider membrane cleaning and longer-term stability.

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.

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.

Modified n-HA/PA66 scaffolds with chitosan coating for bone tissue engineering: cell stimulation and drug release.

Science.gov (United States)

Zou, Qin; Li, Junfeng; Niu, Lulu; Zuo, Yi; Li, Jidong; Li, Yubao

2017-09-01

The dipping-drying procedure and cross-linking method were used to make drug-loaded chitosan (CS) coating on nano-hydroxyapatite/polyamide66 (nHA/PA66) composite porous scaffold, endowing the scaffold controlled drug release functionality. The prefabricated scaffold was immersed into an aqueous drug/CS solution in a vacuum condition and then crosslinked by vanillin. The structure, porosity, composition, compressive strength, swelling ratio, drug release and cytocompatibility of the pristine and coating scaffolds were investigated. After coating, the scaffold porosity and pore interconnection were slightly decreased. Cytocompatibility performance was observed through an in vitro experiment based on cell attachment and the MTT assay by MG63 cells which revealed positive cell viability and increasing proliferation over the 11-day period in vitro. The drug could effectively release from the coated scaffold in a controlled fashion and the release rate was sustained for a long period and highly dependent on coating swelling, suggesting the possibility of a controlled drug release. Our results demonstrate that the scaffold with drug-loaded crosslinked CS coating can be used as a simple technique to render the surfaces of synthetic scaffolds active, thus enabling them to be a promising high performance biomaterial in bone tissue engineering.

Investigations into the early stages of 'in vitro' calcification on chitosan films

International Nuclear Information System (INIS)

Aimoli, Cassiano G.; Torres, Marco A.; Beppu, Marisa M.

2006-01-01

This work investigated the mechanisms involved in the 'in vitro' calcification of chitosan films. The calcification process on chitosan films is a phenomenon that has not been sufficiently studied, despite its importance in the understanding of many natural processes, such as bone and shell formation. Three different techniques were used in the present investigation: X-ray fluorescence (XRF), atomic force microscopy (AFM) and X-ray diffraction (XRD). Natural and acetylated chitosan films were used as substrates for calcification. The experiments were carried out by immersing chitosan membranes in simulated body fluid (SBF) or in a modified version of SBF, prepared without phosphate ions, during 30 min, 3 or 12 h. Calcium maps obtained by XRF showed that the initial calcium distribution on the chitosan surface was influenced by the acetylation treatment of chitosan films. AFM indicated the distribution pattern of calcium compound deposits at different times, obtained by film surface morphological analysis. The results suggest that the calcification mechanism is nucleation on membranes followed by the crystal growth of calcium compounds. AFM showed that the deposit formation is a function of immersion time: the deposits became more homogeneous and covered the surface more evenly with longer immersion times. XRD showed that the acetylated membranes produced more organized calcium deposits

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

Science.gov (United States)

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

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.

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.

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

OpenAIRE

UMA DEVI,THIRUGANESH, SURESH

2013-01-01

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

Effect of Na2SO3 concentration to drug loading and drug release of ascorbic acid in chitosan edible film as drug delivery system membrane

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Kistriyani Lilis

2018-01-01

Full Text Available Chitosan is a type of carbohydrate compounds produced from waste marine products, in particular the class of shrimp, crabs and clams. Chitosan is often process into edible films and utilized for food packaging also has potential as a membrane for drug delivery system. Drug loading and drug release can be controlled by improve the characteristics of the membrane by adding crosslinker. The purpose of this research is to study the effect of addition of crosslinker to the rate of loading and release of ascorbic acid in the chitosan edible film. Na2SO3 was used as crosslinker. Two grams of chitosan was dissolved into 100 ml of distilled water. Acetic acid and plasticizer were added in the solution then heated at 50°C. Na2SO3 solution with mass various of Na2SO3 dissolved, 01026 0.3; and 0.5 grams were added about 30 mL to make edible film. The analysis include of drug loading, drug release and tensile strength. The result showed that the loading of edible film with crosslinker 0.15 g; 0.3 g; and 0.5 g respectively were 60.98 ppm; 52.53 ppm; and 40.88 ppm, meanwhile for the release with crosslinker 0.15 g; 0.3 g; and 0.5 g respectively were 3.78 ppm; 5.72 ppm; and 5.97 ppm.

Electrophoretic deposition of chitosan/45S5 bioactive glass composite coatings doped with Zn and Sr

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Marta eMiola

2015-10-01

Full Text Available In this research work the original 45S5 bioactive glass (BG was modified by introducing zinc and/or strontium oxide (6% mol in place of calcium oxide. Sr was added for its ability to stimulate bone formation, Zn for its role in bone metabolism, antibacterial properties and anti-inflammatory effect. The glasses were produced by means of melting and quenching process. SEM and XRD analyses evidenced that Zr and Sr introduction did not modify the glass structure and morphology, while compositional analysis (EDS demonstrated the effective addition of these elements inside the glass network. Bioactivity test in simulated body fluid (SBF up to one month evidenced a reduced bioactivity kinetics for Zn-doped glasses. Doped glasses were combined with chitosan to produce organic/inorganic composite coatings on stainless steel AISI 316L by electrophoretic deposition (EPD. Two EPD processes were considered for coating development, namely direct current EPD (DC-EPD and alternating current EPD (AC-EPD. The stability of the suspension was analysed and the deposition parameters were optimized. Tape and bending tests demonstrated a good coating-substrate adhesion for coatings containing 45S5-Sr and 45S5-ZnSr glasses, while the adhesion to the substrate decreased by using 45S5-Zn glass. FTIR analyses demonstrated the composite nature of coatings and SEM observations indicated that glass particles were well integrated in the polymeric matrix, the coatings were fairly homogeneous and free of cracks; moreover the AC-EPD technique provided better results than DC-EPD in terms of coating quality. SEM, XRD analyses and Raman spectroscopy, performed after bioactivity test in SBF solution, confirmed the bioactive behaviour of 45S5-Sr containing coating, while coatings containing Zn exhibited no hydroxyapatite formation.

Towards Acid-Tolerated Ethanol Dehydration: Chitosan-Based Mixed Matrix Membranes Containing Cyano-Bridged Coordination Polymer Nanoparticles.

Science.gov (United States)

Wu, C-W; Kang, Chao-Hsiang; Lin, Yi-Feng; Tung, Kuo-Lun; Deng, Yu-Heng; Ahamad, Tansir; Alshehri, Saad M; Suzuki, Norihiro; Yamauchi, Yusuke

2016-04-01

Prussian blue (PB) nanoparticles, one of many cyano-bridged coordination polymers, are successfully incorporated into chitosan (CS) polymer to prepare PB/CS mixed matrix membranes (MMMs). The PB nanoparticles are uniformly distributed in the MMMs without the collapse of the original PB structure. As-prepared PB/CS MMMs are used for ethanol dehydration at 25 °C in the pervaporation process. The effect of loading PB in CS matrix on pervaporation performance is carefully investigated. The PB/CS membrane with 30 wt% PB loading shows the best performance with a permeate flux of 614 g. m-2 . h-1 and a separation factor of 1472. The pervaporation using our PB/CS membranes exhibits outstanding performance in comparison with the previously reported CS-based membranes and MMMs. Furthermore, the addition of PB allows PB/CS MMMs to be tolerant of acidic environment. The present work demonstrates good pervaporation performance of PB/CS MMMs for the separation of an ethanol/water (90:10 in wt%) solution. Our new system provides an opportunity for dehydration of bioethanol in the future.

Conductive PEDOT:PSS coated polylactide (PLA) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) electrospun membranes: Fabrication and characterization

Energy Technology Data Exchange (ETDEWEB)

Chang, Hui Chung [Faculty of Bioscience and Medical Engineering, Universiti Teknologi Malaysia, 81300, Johor (Malaysia); Sun, Tao [Miniaturized Medical Devices Program, Institute of Microelectronics, Agency for Science, Technology and Research - A*STAR (Singapore); Sultana, Naznin, E-mail: naznin@biomedical.utm.my [Faculty of Bioscience and Medical Engineering, Universiti Teknologi Malaysia, 81300, Johor (Malaysia); Advanced Membrane Technology Research Center, Universiti Teknologi Malaysia, 81300, Johor (Malaysia); Lim, Mim Mim [Faculty of Bioscience and Medical Engineering, Universiti Teknologi Malaysia, 81300, Johor (Malaysia); Khan, Tareef Hayat [KALAM, Faculty of Alam Bina, Universiti Teknologi Malaysia, 81300, Johor (Malaysia); Ismail, Ahmad Fauzi [Advanced Membrane Technology Research Center, Universiti Teknologi Malaysia, 81300, Johor (Malaysia)

2016-04-01

In the current study, electrospinning technique was used to fabricate composite membranes by blending of a synthetic polymer, polylactic acid (PLA) and a natural polymer, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), PHBV. Conductive membranes were prepared by dipping PLA/PHBV electrospun membranes into poly(3,4-ethylenedioxythiophene)–poly(styrenesulfonate) (PEDOT:PSS) solution, which is a biocompatible polymer. The coated and uncoated membranes were evaluated using several techniques. The electrical conductivity of the coated membranes was measured using a digital multimeter. In vitro cell cytotoxicity and cell viability were measured by culturing human skin fibroblast (HSF) cells onto the membranes using MTT assays. It was observed that electrospinning of 20% (w/v) PLA/PHBV with a weight ratio of 50:50 produced the most uniform fibers with no beads. It was observed that the wettability and surface roughness of the PEDOT:PSS coated PLA/PHBV membranes were greatly increased than uncoated membrane. The results of cell viability using MTT assay, cell attachment and cell proliferation showed that the conductive PEDOT:PSS coated PLA/PHBV membrane were more favorable for tissue engineering application than their uncoated counterparts. - Highlights: • Coating with PEDOT:PSS increased the wettability of PLA/PHBV membrane. • PEDOT:PSS rendered the PLA/PHBV membrane conductive. • PEDOT:PSS coated PLA/PHBV had significantly higher cell attachment.

Conductive PEDOT:PSS coated polylactide (PLA) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) electrospun membranes: Fabrication and characterization

International Nuclear Information System (INIS)

Chang, Hui Chung; Sun, Tao; Sultana, Naznin; Lim, Mim Mim; Khan, Tareef Hayat; Ismail, Ahmad Fauzi

2016-01-01

In the current study, electrospinning technique was used to fabricate composite membranes by blending of a synthetic polymer, polylactic acid (PLA) and a natural polymer, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), PHBV. Conductive membranes were prepared by dipping PLA/PHBV electrospun membranes into poly(3,4-ethylenedioxythiophene)–poly(styrenesulfonate) (PEDOT:PSS) solution, which is a biocompatible polymer. The coated and uncoated membranes were evaluated using several techniques. The electrical conductivity of the coated membranes was measured using a digital multimeter. In vitro cell cytotoxicity and cell viability were measured by culturing human skin fibroblast (HSF) cells onto the membranes using MTT assays. It was observed that electrospinning of 20% (w/v) PLA/PHBV with a weight ratio of 50:50 produced the most uniform fibers with no beads. It was observed that the wettability and surface roughness of the PEDOT:PSS coated PLA/PHBV membranes were greatly increased than uncoated membrane. The results of cell viability using MTT assay, cell attachment and cell proliferation showed that the conductive PEDOT:PSS coated PLA/PHBV membrane were more favorable for tissue engineering application than their uncoated counterparts. - Highlights: • Coating with PEDOT:PSS increased the wettability of PLA/PHBV membrane. • PEDOT:PSS rendered the PLA/PHBV membrane conductive. • PEDOT:PSS coated PLA/PHBV had significantly higher cell attachment.