Mixture Of Chitosan Research Articles

Enkapsulasi Probiotik Lactobacillus sp. Menggunakan Biopolimer Alginat dan Kitosan dengan Metode Satu Tahap

Lactobacillus sp are gram-positive bacteria that cannot survive in acidic conditions, such as stomach acid conditions (pH 1.5- pH 2.5) so that a carrier is needed so that Lactobacillus sp can survive when colonizing the intestine. One way to protect Lactobacillus sp in acidic conditions is by encapsulation. The core material used for Lactobacillus encapsulation uses a mixture of Na-alginate and chitosan. The mixture formed then becomes microcapsules using an electrospinning device. One of the components of the electrospinning device is a syringe that provides pressure to form droplets that fall into a solution of CaCl2 and chitosan with a concentration of 1.2%; 1.6% and 2%. Lactobacillus sp. The encapsulated viability was tested for viability in simulated gastric acid (0.2% NaCl pH 1.2 and pH 3) for 1 minute, 60 minutes, and 120 minutes using the Total Plate Count (TPC) method. After the viability test was carried out, it was found that Lactobacillus sp. encapsulation results with a 2% chitosan matrix with the number of colonies in the simulated gastric acid pH 3 for 1 minute is 4x109 cfu / g, for 60 minutes 3x109 cfu / g and for 120 minutes is 1x9 cfu /g.

Valorization of Chicken Feather Waste: Fabrication of Keratin‐Chitosan Biofilms

AbstractAccording to scientists, keratin is one of the most abundant fibrous materials in nature after cellulose and chitin in the world. Several nature fibrous materials have a wide range of application starting from biomedical application to the construction sector, and especially the textile sector. The uses of natural fibers in these sectors are economical for increasing their specific properties, such as antibacterial properties, flexibility, tensile strength, shear strength, toughness, etc. This paper presented a new type of keratin‐chitosan biofilms with the separation of keratin from waste chicken feathers. The laboratory‐scale keratin extraction process was designed. The keratin extraction percentage of different lixiviants (NaOH; NaOH+Na2S; Na2S) were studied and compared each other to understand the reaction process. The chosen reaction parameters were lixiviant concentration, reaction time, and temperature in an attempt to figure out their effects on the extraction of keratin. The highest extraction value was achieved at 60 °C and 400 rpm for 6 h, and 0.5 M Na2S per 5 g of chicken feather powder. After obtaining keratin powder from the chicken feather powder, the keratin and chitosan powders were mixed in a certain ratio. Afterwards the polyvinyl alcohol was added into the mixture of keratin and chitosan at 100 °C until forming the biofilms. The properties and structure of the biofilms were characterized and antibacterial properties of films were examined. Owing to its enormous extraction performance using common and cheap chemicals and simple equipment at ambient conditions, the pile processing method has great promise for the keratin bio‐waste's industrially.

Electrospun PCL scaffold modified with chitosan nanoparticles for enhanced bone regeneration

The encapsulation of ascorbic acid within chitosan nanoparticles (CHNs), embedded in a fibrous structure of a dexamethasone (Dex)-loaded PCL scaffold, provides a new plan for osteogenic differentiation of mesenchymal stem cells. This electrospun PCL fibrous scaffold can release Dex, as bone differentiation initiator, and ascorbic acid, as bone differentiation enhancer, in an approximately sustained release pattern for about 2weeks. Ascorbic acid-loaded CHNs were prepared by electrospraying a mixture of chitosan and ascorbic acid, and Dex-containing PCL fibers were prepared by electrospinning a mixture of PCL and Dex. The final PCL/chitosan bilayer scaffolds were obtained by the sequential employment of electrospinning and electrospraying methods. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) confirmed that the CHNs were successfully incorporated into the fibrous PCL matrix. The improved proliferation of hMSCs cultured on the PCL/chitosan scaffolds was also verified. Osteogenic assays showed an increase in alkaline phosphatase activity and mineral deposits. The expression of bone-specific genes also confirmed the osteogenic differentiation of cells cultured on these PCL/chitosan bilayer scaffolds. Dual-drug-loaded PCL/chitosan scaffold enhanced the osteoblast differentiation of hMSC cells and can be served as a potential scaffold for bone tissue engineering.

Biomaterials with Potential Use in Bone Tissue Regeneration-Collagen/Chitosan/Silk Fibroin Scaffolds Cross-Linked by EDC/NHS.

Blending of different biopolymers, e.g., collagen, chitosan, silk fibroin and cross-linking modifications of these mixtures can lead to new materials with improved physico-chemical properties, compared to single-component scaffolds. Three-dimensional scaffolds based on three-component mixtures of silk fibroin, collagen and chitosan, chemically cross-linked, were prepared and their physico-chemical and biological properties were evaluated. A mixture of EDC (N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride) and NHS (N-hydroxysuccinimide) was used as a cross-linking agent. FTIR was used to observe the position of the peaks characteristic for collagen, chitosan and silk fibroin. The following properties depending on the scaffold structure were studied: swelling behavior, liquid uptake, moisture content, porosity, density, and mechanical parameters. Scanning Electron Microscopy imaging was performed. Additionally, the biological properties of these materials were assessed, by metabolic activity assay. The results showed that the three-component mixtures, cross-linked by EDC/NHS and prepared by lyophilization method, presented porous structures. They were characterized by a high swelling degree. The composition of scaffolds has an influence on mechanical properties. All of the studied materials were cytocompatible with MG-63 osteoblast-like cells.

Co, N co-doped porous carbons as high-performance oxygen reduction electrocatalysts

Although the Co and N co-doped carbon catalyst (Co-NC) has attracted much attention because of its low cost and the natural abundance of the dopants, it has a low oxygen reduction reaction (ORR) activity and a high selectivity for the two-electron (2e-) reduction of oxygen to H2O2, which affects its use in fuel cells. Co-NC catalysts were prepared by the pyrolysis of a mixture of cobalt chloride and chitosan pretreated with zinc chloride at 650, 750 and 850 oC, followed by washing with nitric acid and annealing at 900 oC. The results indicate that zinc chloride helps the complexing of chitosan with Co2+, which is also a chemical activator that generates pores, and annealing caused the evaporation of the spherical Zn metal nanoparticles formed by the carbothermal reduction of Zn ions, leading to a unique porous structure of the catalysts with spherical pores filled with spherical carbon nanoparticles formed by the growth of nitrogen-doped carbon as a result of the Co catalyst. The degree of graphitization is also improved by the Co catalyst. The Co-NC catalyst obtained at a pyrolysis temperature of 750 oCshows the same four-electron (4e-) reduction of oxygen as a commercial Pt/C catalyst, and a significantly higher ORR catalytic activity, longer-term stability and better methanol tolerance than a commercial Pt/C catalyst. These are due to its large specific surface area, high contents of pyridinic nitrogen and graphitic nitrogen that disperse the Co species and its excellent electrical conductivity.

Spray-dried thyme essential oil microparticles using different polymeric matrices

The aim of this study was to evaluate the physical, physicochemical, rheological, and morphological properties and antioxidant capacity of thyme essential oil encapsulated by spray drying; as well as to verify the effects of the partial replacement of whey protein isolate by maltodextrin and chitosan. The presence of maltodextrin decreased viscosity of the emulsion; decreased moisture, density, and mean volume diameter, and maintained the oil retention percentage and solubility of the microparticles. All treatments showed low hygroscopicity, being chitosan considered an alternative to reduce this parameter. Phenolic monoterpene thymol was characterized as the major constituent in all samples. The carrier agents were efficient in maintaining antioxidant activity when compared to pure thyme essential oil. In general, they showed spherical shapes and smooth surfaces with slight roughness. The mixture of maltodextrin and chitosan, in partial replacement of whey protein isolate, represents a promising opportunity in obtaining thyme essential oil microparticles by spray drying process.

Characterization of chitin content extracted from edible insect, Coridius nepalensis (Westwood, 1837) (Hemiptera: Dinidoridae)

Chitin is the second most abundant bio-polymer after cellulose in earth. This carbohydrate polymer is one of the major components of the cell wall of some micro-organisms and exoskeleton of certain invertebrates. Recent studies show the potential application of chitin and its derivatives in chemical, medical, agricultural, food technology, pollutant treatment and textile sectors. The traditional resources of chitin for industrial processing are crustacean shells and fungal mycelia. This work attempts to extract and characterize chitin from the edible insect Coridius nepalensis. The results were compared with the commercial chitin extracted from shrimp (Pandalus borealis). The chitin yield of from C. nepalensis was found to be 43.97% of its dry weight. The degree of acetylation was recorded as 57.67%. FT-IR spectrum showed the extracted chitin as α-allomorph. The peaks of the chitin extracted from C. nepalensis in X-ray diffractogram are less sharp compared to commercial shrimp chitin. Thus, the degree of acetylation, FT-IR spectrum and XRD show mixture of chitin and chitosan in the extracted chitin from C. nepalensis. The crystalline index (CrI110) for C. nepalensis and commercial shrimp chitin was calculated as 86.33% and 71.56% respectively. Scanning electron micrographs indicated granular surface morphology the extracted chitin of C. nepalensis, in contrast to commercial shrimp chitin, which was fibrous and porous. Thus, the present study indicates the possibility to use the adults of C. nepalensis as a new and alternative source of biomaterial.

Effects of chitosan-collagen dressing on wound healing in vitro and in vivo assays.

The present study was designed to fabricate a new chitosan-collagen sponge (CCS) for potential wound dressing applications. CCS was fabricated by a 3.0% chitosan mixture with a 1.0% type I collagen (7:3(w/w)) through freeze-drying. Then the dressing was prepared to evaluate its properties through a series of tests. The new-made dressing demonstrated its safety toward NIH3T3 cells. Furthermore, the CCS showed the significant surround inhibition zone than empty controls inoculated by E. coli and S. aureus. Moreover, the moisture rates of CCS were increased more rapidly than the collagen and blank sponge groups. The results revealed that the CCS had the characteristics of nontoxicity, biocompatibility, good antibacterial activity, and water retention. We used a full-thickness excisional wound healing model to evaluate the in vivo efficacy of the new dressing. The results showed remarkable healing at 14th day post-operation compared with injuries treated with collagen only as a negative control in addition to chitosan only. Our results suggest that the chitosan-collagen wound dressing were identified as a new promising candidate for further wound application.

Soft solution in situ synthesis of chitosan/iron oxide nanocomposites and their magnetic properties.

Chitosan/iron oxide nanocomposites (CS/IO) were synthesized by using soft solution in situ synthesis. An aqueous mixture of iron(ii), iron(iii) and chitosan was added drop by drop to a solution of a sodium tripolyphosphate crosslinker with stirring for 30 min, resulting in in situ ionically crosslinked chitosan, with incorporated Fe2+ and Fe3+ (CS/Fe2+Fe3+). The CS/Fe2+Fe3+ precursors were then treated in alkaline solution by two different methods, i.e. hydrothermal and refluxing, where the Fe2+ and Fe3+ ions reacted to form quasi-spherical magnetite-maghemite nanocrystals in the constrained space of the crosslinked chitosan CS/IO nanocomposites. The pressurized hydrothermal system promoted the growth of iron oxide nanocrystals, leading to slightly larger crystallites (3.9-4.3 nm), compared to 3.9 nm from the refluxing system. The iron oxide crystallites also became smaller with increased crosslinking density of the chitosan matrix. The resultant CS/IO nanocomposites exhibited superparamagnetism with Mmax in the range of 9.6-15 emu g-1 and low coercivity and magnetic remanence. In addition, they showed high cell viability, 82-96%, indicating them as potential candidates for medical applications.

Ni2P/CoP loading on Porous carbon matrix for hydrogen evolution

Due to high specific surface and plentiful of porosity, 3D porous carbon matrix has shown enormous potential for catalyst supporters. Hydrogen was thought as the next-generation clean energy to substitute the fossil fuel. Metal phosphides has been investigated and exhibited a good catalytic performance for hydrogen evolution reaction (HER). In this work, we prepared Ni2P/CoP loading on Porous carbon matrix through a facile method. The mixture of nickel nitrate, cobalt nitrate and chitosan was ball-milled, then was carbonized under N2 atmosphere at 900°C with NH4HPO2. The as-obtained materials were characterized by X-Ray diffraction (XRD), SEM and Raman spectrums. Also the electrochemical performance for HER was test using electrochemical workstation. The result shown that this catalysts presented a low overpotential at 10 mA cm-2, which was 270 mV.

Preparation of gels of chitosan through a hydrothermal reaction in the presence of malonic acid and cinnamaldehyde: characterization and antibacterial activity

The preparation of composite gels through the hydrothermal reaction of a mixture of chitosan (CH), malonic acid (MLA), urea (UR) and cinnamaldehyde (CA), all of which are sustainable materials, is reported.

Electrochemical glucose sensor based on the glucose oxidase entrapped in chitosan immobilized onto laser-processed Au-Ti electrode

Abstract Glucose is essential to keep the human body in well order. Therefore, the control of its level is of key importance. The study on novel electrode material composed of structured titanium foil with embedded Au nanoparticles and modified with chitosan with entrapped glucose oxidase is presented. In the first step, Ti foil undergoes anodization followed by chemical etching resulting in formation of homogenously distributed inverted caps of diameter of 85 nm. After deposition of thin Au layer, the rapid and well optimized laser dewetting is applied to form Au nanoparticles of size limited by the dimensions of cavities. Finally, the surface is modified using enzyme and chitosan mixture. To confirm the successful immobilization of glucose oxidase FT-IR analysis was performed. The response of electrodes were tested towards glucose in 0.1 M PBS containing most different interference compounds and biological fluids. It is proven that prepared material exhibits excellent performance for glucose detection with a wide linear range of 0.04–15.05 and 15.05–40.00 mM, with sensitivity of 23.47 ± 1.36 and 10.63 ± 1.28 μAcm−2 mM-1, respectively, and very low limit of detection 1.75 ± 0.30 μM. The perfect selectivity and stability promotes the material selection as the main biosensor component.

Development of Chitosan/Starch-Based Forward Osmosis Water Filtration Bags for Emergency Water Supply.

A forward osmosis (FO) membrane was developed from a mixture of chitosan and Dioscorea hispida starch, cross-linked using glutaraldehyde. The cross-linked chitosan/starch membrane was revealed to have high mechanical properties with an asymmetric structure. The prepared membrane’s performance was investigated as an FO filter assembled in a polypropylene water filter bag and aluminum foil plastic. In order to study the FO process, brackish water was used as a feed solution, drawn using three types of solution (fructose, sucrose, and fructose/sucrose mixture, each with 3 M concentration). The maximum water flux (5.75 L/m2 h) was achieved using 3 M sucrose. The cross-linked membrane restrained the ions in the feed with a rejection factor value close to 100%. The water quality parameters were evaluated for the physical, chemical, and biological criteria, such as pH, salinity, conductivity, total dissolved solids (TDS), heavy metals, and Escherichia coli content. The water quality parameters for the FO-processed water met that set by the World Health Organization for drinking water. FO filter bags with cross-linked chitosan/starch membranes can be an option to produce drinking water during an emergency.

Дослідження антимікробної дії хітозану та біологічно активних композицій на його основі

Due to the large number of functional groups in chitosan is provide the possibility of formation bonds with chemical compounds, which allows you to create polymeric complexes with new physicochemical properties and biological activity. Therefore, chitosan is widely used as a biopolymeric carrier of degradable preparation of different orientation, which ensures their effective and prolonged action. Compositions of chitosan with natural biopreservatives, which allow to obtain promising plant protection products and agricultural products, deserve special attention. Recent developments, as well as the need for safe, practical and effective food preservatives have aroused increased interest in substances such as sorbate and its combined use with chitosan. In recent decades, sorbate and chitosan have been tested and widely used in the storage of various foods around the world. The issues of adaptogenic action, antimicrobial activity of chitosan in combination with biologically active components remain little studied in Ukraine. Given the global trend towards a gradual transition to organic production, the study of the mechanisms of action of chitosan and its compounds with organic acids is a promising area of research in the control of pathogenic microorganisms for storage of fruits and vegetables. The aim of the study was to study the effectiveness of the integrated use of chitosan with sorbic acid against phytopathogenic microorganisms. The research used methods generally accepted in microbiology and phytopathology. Specificity of antimicrobial activity and prolongation of action of chitosan, sorbic acid and their mixture with respect to different isolates and strains of phytopathogenic microorganisms has been established. The bacteriostatic effect of a mixture of chitosan and sorbic acid in the variant with bacterial isolates, which was observed during 5 days was investigated. The composition of chitosan and sorbic acid contributed to the inhibition of mycelial growth of isolates of pathogens of the genera Fusarium and Alternaria.

Preparation of iron and nitrogen co-doped carbon material Fe/N-CCM-T for oxygen reduction reaction

In this paper, iron and nitrogen co-doped carbon material with nanotube structure (Fe/N-CCM-T) was synthesized by pyrolyzing a mixture of Fe salt, chitosan and melamine and displayed high electrocatalytic performance for oxygen reduction reaction (ORR). The structure of the Fe/N-CCM-T was characterized and their ORR performance in alkaline media was investigated by linear sweep voltammetry, cyclic voltammetry and chronoamperometry. Fe/N-CCM-T displayed better ORR performance than other carbon materials like Fe/N-CC-800. The Fe/N-CCM-800 with a large surface area (302.5 m2/g) especially exhibited the best ORR electrocatalytic performance among the prepared carbon materials, which was also proved by its similar Tafel slope (76 mV decade−1) to Pt/C catalyst (74 mV decade−1). Fe/N-CCM-800 showed similar ORR activity as commercial Pt/C catalyst, but superior tolerance to methanol and stability. Such high ORR performance of the Fe/N-CCM-T can be attributed to its nanotube structure, high specific surface area (SSA), high graphitic-N and pyridinic-N contents.

Aplikasi Label Pintar Edible dari Ekstrak Antosianin Ubi Jalar Ungu (Ipamoea Batatas L.) untuk Monitoring Kesegaran Sayuran Cabai Hijau (Capsicum Annuum L.)

Vegetable products are foods that are popular with many people. One vegetable product such as green chili is a vegetable commodity that cannot be abandoned by society in daily life. This was followed by demands for quality of green chili products. so that an analytical tool is needed that can analyze the freshness of green chili easily and practically. This study aims to develop an edible freshness sensor based on anthocyanin indicators from purple sweet potato extract (Ipomoea batatas L.) with a membrane mixture of cassava starch and chitosan. The edible freshness sensor can be applied as a freshness sensor and know the freshness level of green chili with various parameters. Tests for green chili freshness test included pH test, weight loss, texture value, and sensory evaluation test. The color change of the edible freshness sensor was observed visually and tested using the ImageJ program to determine the mean green value. The results show the color change of the freshness sensor is dark purple when the green chili is fresh, the light purple is still fresh and the light green is no longer fresh or rotten. The mean value of the green sensor for edible freshness increased along with the decline in the quality of green chili in the packaging.
 Keywords: Anthocyanin, tapioca starch, chitosan, green chilli

Facile recovery of gold from e-waste by integrating chlorate leaching and selective adsorption using chitosan-based bioadsorbent

Recovery of gold from electronic wastes, particularly waste printed circuit boards (WPCBs), has received significant attention due to its high gold content and economic value. This study reports a novel method for efficient and selective recovery of gold from WPCBs using an integrated chlorate leaching and chitosan-based bioadsorption. The experimental conditions of the leaching step were optimized, and ∼100 % leaching efficiency of gold could be achieved when 0.5 g of WPCB sample was treated with 12.5 mL (liquid to solid ratio of 25) of a mixture of chlorate (0.2 M) and chitosan (1% w/v) in 2 M HCl at 55 °C for 5 h. The WPCB leachate containing gold and other metal ions (e.g. Cu and Al) was diluted three-fold and then treated with glutaraldehyde-crosslinked chitosan (GCC) beads, achieving selective and complete adsorption of gold at GCC dose of ≥1 g/L. The adsorbed gold on GCC could be fully desorbed by using a thiourea/HCl mixture (each 0.2 M). The high efficiency of gold adsorption-desorption could be maintained up to four successive cycles, signifying long-term reusability of the GCC. As an alternative approach, thermal decomposition of the gold-adsorbed GCC at 650 °C was shown to generate sponge-like gold residue with 97.8 % purity. These results indicated high efficiency of the proposed method for recovering gold from e-waste along with its simple process steps, low chemical usage and low cost.

In Vitro Study for Nano Hydroxyl Apatite and Chitosan Coated Surface after Immersion in Simulated Body Fluid

Multiple attempts are made to develop coating layers on the implant surface to enhance ossiointegration andsupport implant functions. The mixture of chitosan with HA prepared by sol–gel process to make organic–inorganic hybrid composite that has the ability to make network with or without covalent bonds betweencomponents.In this study the immersion of titanium disc coated via sol – gel technique by nano-HA and chitosan insimulated body fluid.Materials and Method: Composite of nano hydroxy apatite/chitosan was prepared by sol – gel techniqueafter preparation of two solutions of calcium nitride and phosphorous pentaoxide, then the magnetic stirrerwas used for mixing of these solutions, then 3 mg of chitosan were added to the mixture and the mixturewas stirrer for 15 hours to complete the mixing. Dip coated of titanium samples, then the samples wereremoved and dried by hot air oven, finally samples were sintered at 4000C for one hour. Coated sampleswere immersed in SBF in closed containers and placed in incubators at temperature 370C for 30 days.Analysis of the surface include thickness measurement, X-ray diffraction (XRD), scanning electronmicroscopy (SEM) and energy-dispersive x-ray spectroscopy (EDX).The results of thickness measurement showed increase in thickness of the coated layer after immersion inSBF compared with thickness before immersion. The results of XRD showed the appearance of new peaksof HA, SEM showed there are additional accumulation of HA granules on the original coating layer. EDXtest showed decreased in the concentration of the main ions component (Ca, Na, P, O and K) when comparedwith coated samples before immersion in SBF.

The role of interlayers in enlarging the flux of GO membranes

A graphene oxide (GO) membrane can be easily made by filtering a GO solution onto a supporting layer, and such a membrane is effective at adsorbing ions. But low flux and a high work pressure become an obstacle for its application in wastewater treatment. In this study, a positively charged mixture of carbon nanotubes and chitosan (CNTS) served as an interlayer to improve the GO membrane’s flux. The three-layer membrane is known as MCG, while one without an interlayer is known as MG. For MCG and MG with the same GO load, the water flux of MCG reaches 2–8 times larger than that of MG. A better water permeability is consistently detected for MCG, with a contact angle descent speed of 3.3°/s, which is significantly faster than that of MG (0.5°/s). The ion rejections of MCG and MG are mostly attributed to GO adsorption, which stay at the same level. The flux varies with GO load, CNTS load and membrane dryness, while the ion rejection is correlated with the GO load. Optimized membrane fabrication conditions are suggested as being a CNTS load of 0.72 g m−2 and a GO load of 0.4 g m−2. A ‘gap’ mechanism is suggested to explain the interlayer effects. The rougher interlayer surface produces gaps between the GO and CNTS layers, which results in the faster water permeation and higher flux of MCG. These results demonstrate that it is possible to fabricate high flux GO membranes by adding a controlled-roughness interlayer.

Study of vitamin E microencapsulation and controlled release from chitosan/sodium lauryl ether sulfate microcapsules

Potential benefit of microencapsulation is its ability to deliver and protect incorporated ingredients such as vitamin E. Microcapsule wall properties can be changed by adding of coss-linking agents that are usually considered toxic for application. The microcapsules were prepared by a spray-drying technique using coacervation method, by depositing the coacervate formed in the mixture of chitosan and sodium lauryl ether sulfate to the oil/water interface. All obtained microcapsules suspensions had slightly lower mean diameter compared to the starting emulsion (6.85 ± 0.213 μm), which shows their good stability during the drying process. The choice and absence of cross-linking agents had influence on kinetics of vitamin E release. Encapsulation efficiency of microcapsules without cross-linking agent was 73.17 ± 0.64 %. This study avoided the use of aldehydes as cross-linking agents and found that chitosan/SLES complex can be used as wall material for the microencapsulation of hydrophobic active molecules in cosmetic industry.