Preparation Of Chitosan Research Articles

Chitosan Nanoparticles as a Novel Drug Delivery System: A Review Article.

Natural polymers, particularly polysaccharide, have been used as drug delivery systems for a variety of therapeutic agents such as peptides, proteins, vaccines, DNA, and drugs for parenteral and non-parenteral administration. Chitosan, the second most abundant naturally occurring polysaccharide after cellulose, is a biocompatible and biodegradable mucoadhesive polymer that is extensively used in the preparation of nanoparticles (NPs). Chitosan NPs loaded with drugs were found to be stable, permeable and bioactive. In this review, the importance of chitosan and its derivatives in drug delivery is illustrated, different methods of preparation of chitosan and chitosan derivatives NPs and their physio- chemical properties are addressed. Moreover, the desirable characteristics of successful NPs based drug delivery systems, as well as the pharmaceutical applications of these NPs are also clearly explored.

Facile preparation of chitosan coated silver nanoparticles embedded cotton fabric for point-of-use water disinfection

In this study, chitosan (CS) coated Ag nanoparticles (Ag NPs) embedded cotton fabric (Ag NPs-C/CS) was prepared by in-situ thermal reduction of AgNO3 followed by a subsequent coating of porous CS membrane. The introduction of the CS membrane could prevent the excessive release of Ag into the treated water and allow more substantial Ag NPs loading, thereby significantly improving the bactericidal efficiency and stability. With 1.5 wt% of CS, the bactericidal efficiency against Bacillus subtilis and Escherichia coli of the functional material achieved 3.0 and 4.0 log reduction, respectively. Additionally, Ag NPs-C/CS was successfully applied for natural water disinfection, with silver content under 50 µg/L in the processed water.

Development of sustainable magnetic chitosan biosorbent beads for kinetic remediation of arsenic contaminated water

We report the preparation of both control chitosan and magnetic chitosan beads as biosorbents using chitosan as matrix and magnetite (Fe3O4) nanoparticles as reinforcement followed by detailed advanced characterization. The batch trials were performed to study the adsorption kinetics of biosorbents by removing As(III) and As(V) species from water systems. The experimental data was inserted into Langmuir and Freundlich's isotherms to undertake the mechanism and adsorption capacity of the test biosorbents. Under Langmuir's isotherm, maximum monolayer adsorption capacity (qmax) of the biosorbent was observed to be 73.69 and 79.49 mg/g for As(III) and As(V) species, respectively, under specified conditions. The optimum doses of 1.5 and 2 g/L of MCBB at pH 6.7 showed 99.5 and 99% removal of As(V) and As(III), respectively. The analysis demonstrated that the biosorption process obeyed pseudo 2nd order kinetics with linear regression coefficient (R2) of >0.999. The regeneration and reusability of biosorbents were also assessed.

Preparation and characterization of porous chitosan–based membrane with enhanced copper ion adsorption performance

Since compactness is a disadvantageous characteristic of chitosan-based membranes, two different methods were used to increase the porosity of the chitosan/poly(vinyl alcohol)/polyethyleneimine (CS/PVA/PEI) membrane, and its effect on copper ion adsorption was studied. In the first method, selective dissolution of poly(vinyl pyrrolidone) (PVP) induced porosity and for the second method, a mixed solvent system, which consists of a volatile solvent (acetone), was used to improve the porosity of the membrane. Different percentages of PVP showed inadequate performance, but acetone improved the operation efficiency of adsorption. The membranes were characterized by the analysis of FT-IR, SEM, BET, swelling degree, and porosity. Adding acetone to the membrane mixture solution increased the adsorption capacity by about 50%. The experimental results at different temperatures (25, 35, 45 and 55 °C) showed that the Cu2+ uptake was decreased with an increase in the temperature. Furthermore, pH had an important effect on the adsorption capacity of the copper ions. Nonlinear regression was applied to fit the isothermal and kinetic models. Reusability test with 0.05 M Na2EDTA showed less than 8% reduction in adsorption capacity of the modified membrane after four cycles of adsorption–regeneration.

Effects of lactic acid and mixed acid aqueous solutions on the preparation, structure and properties of thermoplastic chitosan

In this paper, a lactic acid (LA) aqueous solution and a mixed acid (MA) aqueous solution, composed of lactic acid and hydrochloric acid (HCl), were used as plasticizers to plasticize thermoplastic chitosan. The plasticizing behavior of chitosan under melt processing with different concentrations of the LA and MA solutions and different ratios of HCl and LA were studied. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) indicated that the acidity and concentration of the acid solution had direct impacts on the chitosan structure. The thermal melting effect of chitosan was improved with increasing lactic acid concentration in the LA solution and HCl concentration in MA solution. The sheet light transmission, hydrophobicity, thermal stability and mechanical properties of thermoplastic chitosan could be adjusted by changing the ratios of hydrochloric acid and lactic acid in the MA solution. This work expanded the theoretical knowledge of acid solution modified thermoplastic chitosan.

Facile preparation of chitosan modified magnetic kaolin by one-pot coprecipitation method for efficient removal of methyl orange

Chitosan modified magnetic kaolin (CS/kaolin/Fe3O4) composite was prepared by a facile one-pot coprecipitation method and used for the removal of methyl orange (MO) from aqueous medium. Under alkaline condition, Fe3O4 nanoparticles were deposited on the kaolin layer by in-situ growth method and chitosan was deposited on the kaolin layer by pH-precipitation method. With the modification of CS, adsorption sites for anionic species were introduced onto the adsorbent. The prepared CS/kaolin/Fe3O4 could remove more than 94 % of MO and showed a high saturated adsorption capacity of 349.7 mg/g. The adsorption process was controlled by film diffusion and well described by Langmuir model. The thermodynamic studies indicated that the adsorption process was exothermic in nature. Furthermore, the adsorbent exhibited satisfactory recycle ability. The results suggested that the modification with CS broadened the application scope of kaolin in anionic species removal and the CS/kaolin/Fe3O4 composite could be a promising adsorbent for wastewater treatment.

Antioxidant, Cytotoxic and Antimicrobial Activity of Chitosan Preparations Extracted from Ganoderma Lucidum Mushroom.

Two chitosan extracts were prepared by chemical and enzymatic treatment of Ganoderma lucidum mushroom, as an alternative source to crustacean shells. The molecular weight of the enzymatic extract was lower than that of the chemical one and of shrimp chitosan, as determined by viscosity measurements. Characteristic signals were identified in the 1 H-NMR spectra and high deacetylation degree indicated good physico-chemical properties for both mushroom chitosan extracts. The scavenging capacity of mushroom chitosan extracts was moderate against the synthetic radicals of 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH), but higher values were observed for the enzymatic extract, compared to the chemical extract and shrimp chitosan. In vitro cytotoxicity was evaluated in L929 mouse fibroblast cell lines and the results of MTT assay showed good cytocompatibility in the tested range of concentrations. The growth of Gram-positive bacteria was inhibited more than Gram-negative bacteria in the presence of mushroom chitosan extracts, in particular by the chemical one, indicating their efficiency as antimicrobial agents. All these results strengthen the evidence of mushroom polysaccharide preparations availability for biomedical applications.

Anticancer and antibacterial activity of chitosan extracted from shrimp shell waste

Abstract Chitosan is a bio-based polysaccharide having promising biological and antitumor properties. The present study aims at the synthesis of chitosan using shrimp shell waste. Chitosan preparation consists of two consecutive steps such as demineralization and deproteinization. The structure, morphology and optical properties of the obtained chitosan were established using various instrumental techniques like XRD, FTIR, UV–Vis, SEM and TEM. Herein, we have shown that Significant bacterial activity was manifested by chitosan against both gram positive (S. aureus and S. mutans) and gram negative (E. coli and P. aeuriginosa) bacteria. The biosynthesized chitosan exerts an inhibitory effect on the proliferation of MCF-7 breast cancer cells in a dose –dependent manner while being non -toxic to fibroblast L929 normal cells.

Preliminary Study of Chitosan Coating Silica Derived from Geotermal Solid Waste

Purpose: The purposes of this research are to study preparation of chitosan coating silica aerogel derived from solid geothermal waste as adsorbent of CO2 and CH4 separation and to study CO2 adsorption kinetics on chitosan coating silica aerogel by Pseudo First Order and Second Order methods. Methodology was conducted consisting of several steps. First, geothermal silica was leached with H2SO4 20% 1: 5 w/v. Then, chitosan was added into silica with ratio of 1.3: 10, 1.5: 10, 1.9: 10, 2.2: 10, and 2.4: 10 w/v. Isopropyl alcohol was added to silica sol to form hydrogel and remained in gelation. The addition of n-hexane was carried out to occur the solvent exchange process. The gel was dried by ambient pressure drying method. CO2 in biogas was removed of using 20 g of adsorbent chitosan coating silica aerogel. The experimental adsorption kinetics analyzed by both pseudo first and second order kinetics model. Results showed that impurities in geothermal silica required to be purified and it can be synthesized into silica aerogel. The remaining geothermal can act as adsorbents to silica aerogel coated with chitosan by using packed column. The data obtained was kinetics data from the pseudo first and second order method. The silica from solid geothermal waste has the potential as CO2 adsorbent. Applications/ Originality/ Value: It was confirmed that silica from solid geothermal waste can be used as CO2 adsorbent. Therefore, the improvement of innovation in the future of this research is to prepare chitosan coating silica aerogel as CO2 adsorbent.

Preparation and Characterization of Chitosan Coated PLGA Nanoparticles of Resveratrol: Improved Stability, Antioxidant and Apoptotic Activities in H1299 Lung Cancer Cells

Resveratrol (RES) is a polyphenolic compound which has shown beneficial pharmacological effects such as anti-inflammatory, antioxidant, and anti-cancer effects. However, poor aqueous solubility, bioavailability, and low stability are the major limitations to the clinical application of RES. Therefore, in the present study, chitosan (CS) coated PLGA nanoparticles of RES (CS-RES-PLGA NPs) was developed, characterized and its anticancer activity was evaluated in the H1299 lung carcinoma cell line. The effects of the increase in CS coating and cryoprotectant concentration on particle size, polydispersity index (PDI) and zeta potential (ZP) were determined. The particle size, PDI, ZP and entrapment efficiency of the optimized CS-RES-PLGA NPs were found to be 341.56 ± 7.90 nm, 0.117 ± 0.01, 26.88 ± 2.69 mV and 75.13% ± 1.02% respectively. The average particle size and ZP showed a steady increase with an increase in CS concentration. The increase in positive zeta potential is evident for higher CS concentrations. The effect of trehalose as cryoprotectant on average particle size was decreased significantly (p < 0.05) when it was increased from 1%−5% w/v. TEM and SEM showed uniform particle distribution with a smooth surface and spherical shape. The CS coating provides modulation of in vitro drug release and showed a sustained release pattern. The stability of RES loaded PLGA NPs was improved by CS coating. CS-coated NPs showed greater cytotoxicity and apoptotic activities compared to free RES. The CS coated NPs had a higher antioxidant effect than the free RES. Therefore, CS coated PLGA NPs could be a potential nanocarrier of RES to improve drug solubility, entrapment, sustain release, stability and therapeutic application.

Preparation of cross-linked magnetic chitosan with methionine-glutaraldehyde for removal of heavy metals from aqueous solutions

ABSTRACTA new nanobiosorbent based on cross-linked chitosan magnetic beads modified with methionine-glutaraldehyde schiff’s base (MG-Chi/Fe3O4) was synthesised for removing Cu(II), Pb(II) and Cd(II) from wastewater samples. Fourier transform infrared spectra (FTIR), X-ray diffraction (XRD) analysis, and scanning electron microscope (SEM) have been applied to characterise nanobiosorbent. A variety of parameters influencing uptake behaviours of the metal ions, including pH, adsorbent dose, contact time, initial concentration of the metal ions and desorption conditions were examined and optimised. The pH ZPC of MG-Chi/Fe3O4 was found to be 4.0. Freundlich and Langmuir isotherm models were applied to estimate adsorption mode. The equilibrium data were well fitted with the Langmuir isotherm model. The maximum adsorption capacities for Cu(II), Pb(II), and Cd(II) were 172.4, 175.4 and 163.9 mg g−1, respectively. The adsorption kinetics fitted better with the pseudo-second-order model indicating that chemical adsorption is the rate-limiting step in the adsorption process. The adsorbent (MG-Chi/Fe3O4 nanobiosorbent) performance is maintained for at least 4 adsorption-desorption cycles. Finally, MG-Chi/Fe3O4 nanobiosorbent exhibited high potential to remove the metal ions from Iran Khodro’s wastewater.

Preparation and Characterization of Nano-Hydroxyapatite Particles and Chitosan by Sol–Gel Method (in Vitro Study)

Successful osseointegration of dental implants depends on many factors, including implant stability, bone quality, implant surface condition, and implant materials. Implant surface is coated using different techniques to enhance osseointegration. Sol–gel technique is one of the modern and easy techniques in the production of more bioactive hydroxyapatite (HA). In this study, nano-HA and chitosan were used to coat titanium disc via the sol–gel technique. Materials and Method: The nano-HA/chitosan composite was prepared using calcium nitride and phosphorus pentoxide solutions. The solutions were drop wisely mixed on a magnetic stirrer. Then, 3 mg of chitosan was added to the mixture, and the mixture was stirred for 15 h. Titanium samples were dip coated in the mixture of chitosan/HA on the stirrer at slow speed for 90 min to precipitate the coating layer. Afterward, the samples were removed and dried in a hot air oven. They were sintered at 400 °C for 1 h. X-ray diffraction (XRD), light microscopy, scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX), FTIR analysis, and atomic force microscopy (AFM) were used to analyze the surface and thickness. The results of XRD test showed that HA particles had sharp diffraction peaks, indicating high crystallinity of the structure due to the sol–gel preparation. Results of optical light microscopy showed that the coated layer was fairly distributed on titanium samples. SEM results of the coated samples showed different surface features, which present a roughness with the appearance of a crystal pool with irregular accumulation of small, spherical-like granules. EDX analysis showed the presence of ions that comprised HA. AFM analysis of the coated sample indicated peaks and projections with average surface nano-roughness (10.1 nm) and grain size (2022–2057 nm). FTIR analysis showed the presence of a band associated with HA particles and amide groups associated with chitosan. The average of thickness readings was 60 ?m.

Chitin, Chitosan, and Submicron-Sized Chitosan Particles Prepared from Scylla serrata Shells

Extraction of chitin from mud crab (Scylla serrata) shells, involving demineralization and deproteinization, and deacetylation of the extracted chitin to form chitosan were investigated. The mud crab chitin and chitosan were obtained with a good yield (16.8% and 84.7% based on dried weight basis). The physicochemical properties, functional groups, molecular weight, and degree of acetylation of the chitin and chitosan were characterized. The surface morphology, the orientation arrangement of polysaccharide strands, and crystallinity of the chitin and chitosan prepared from the mud crab shells were investigated. SEM, FTIR, and XRD analyses demonstrated that the chitin consists of micron-sized fibrils, belonging to α from with the crystallinity of 60.1%. The chitosan has a viscosity-average molecular weight of 6.83 kDa with the degree of acetylation being 9.6% and the crystallinity of 73.8%. The chitosan was successfully fabricated into submicron-sized particles using top-down ionotropic gelation, microwave, and microemulsion methods, employing sodium tripolyphosphate, potassium persulfate, and glutaraldehyde as reagents, respectively. Overall, the results indicated that the preparation of chitin, chitosan, and submicron-sized chitosan particles from mud crab shells could open the opportunity for the value-added seafood waste to be utilized in a wide range of practical applications.

Preparation and characterization of chitosan grafted poly(lactic acid) films for biomedical composites

AbstractPolymer composites offer a great advantage in biomedical field over the traditional materials used like, metal, ceramics, or polymer alone. Polymer composites provide tailor-made facilities to design required physiological and mechanical properties in biomedical products. Poly(lactic acid) (PLA) is a popular aliphatic polyester used in various biomedical products because they have a renewable source and after resorption they enter well into the Krebs cycle of the human body. However, PLA suffers from hydrolysis and subsequent weight loss in aqueous environment. To improve the hydrolytic properties of hydrophobic PLA and to incorporate the biocompatibility from chitosan (CS) into it, in this study CS has been grafted onto PLA film. CS with 78% of degree of deacetylation and viscosity average molecular weight of about 8,31,760 Da was grafted onto hydrolyzed PLA film surface. Kjeldahl analysis confirmed the attachment of CS onto the PLA films. From thermal stability analysis, it was observed that percentage of weight retention at 600°C of the CS-g-PLA was around 15% higher than that of pure PLA. The mechanical properties of final CS-grafted-PLA composites showed more resistance to hydrolytic degradation than that of pure PLA film.

The physicochemical properties of chitosan prepared by microwave heating.

The aim of this study was to compare the physicochemical properties of chitosan prepared by microwave and water bath heating with an equivalent quantity of heat intake. The structure and physicochemical properties of the chitosan obtained by these two methods were characterized by Fourier transform infrared spectroscopy (FTIR), X‐ray diffractometry (XRD), gel permeation chromatography (GPC), and scanning electron microscopy (SEM). The FTIR and XRD patterns show that there was no significant difference in the structure of chitosan produced by the two heat sources. The results showed that chitosan with 73.86% deacetylation was successfully prepared by microwave heating within 60 min, while a longer time of 180 min was required for the preparation of chitosan with the same deacetylation degree (74.47%) using the conventional heating method under the same heating rate. Even under the same temperature conditions, microwave technology can greatly reduce the reaction time by approximately 1/3, while the chitosan produced by microwaves can obtain relatively low molecular weight and viscosity. These results showed that microwaves may efficiently promote complete chemical reactions by the friction heating mechanism generated by molecular vibration beyond a rapid heating source, turning into a more efficient, energy‐saving, and environmentally friendly method for the further use of rigid shrimp shells and highly crystalline crustacean materials.

Preparation of low molecular weight chitosan by pawpaw protease

Pawpaw protease was used to degrade chitosan, and then obtained low molecular weight chitosan and reducing sugar in this study. According to the orthogonal experiment on the degradation of chitosan by pawpaw protease, the effects of temperature, pH value, reaction time and enzyme dosage on the decomposition efficiency of chitosan were investigated with the concentration of reducing sugar in the degradation solution as the index. The experimental results show that the optimal conditions for the degradation reaction are: the pH value of 4.1 and the reaction temperature of 42 °C, the reaction time of 1.4 h and the amount of enzyme of 30 U/mg, the concentration of reducing sugar in the degradation solution of 1.57 g/L and the yield of 15.7%.

Heterologous expression and characterization of a novel chitin deacetylase, CDA3, from the mushroom Coprinopsis cinerea

The chitin deacetylase CDA3 from C. cinerea deacetylated chitin-oligosaccharides with dp ≥ 2. Since CDA3 firstly removed the intermediate acetyl group of (GlcNAc)4, it was an endo-acting deacetylase. Different from previously reported deacetylation modes, CDA3 deacetylated chitinbiose at either the reducing end or the nonreducing end; CDA3 deacetylated chitintriose at any subsite including the end and the intermediate; CDA3 further removed acetyl groups at any subsite, the intermediate, nonreducing and reducing end of chitintetraose after removal of the first intermediate acetyl group. 3D structural analysis showed that CDA3 has aromatic amino acids distributing at both the +1 and −1 subsites of the catalytic site, which may be responsible for its distinctive deacetylation mode. Furthermore, CDA3 was active on crystalline chitin, its deacetylation activity increased with the DA decreases of chitinous substrates and showed a higher activity towards the cell wall of the basal stipe with the higher molar ratio of GlcN/GlcNAc than that of the apical stipe with the lower molar ratio of GlcN/GlcNAc. CDA3 with distinctive deacetylation mode and activity indicates its function during the maturation of the fruiting bodies of C. cinerea and a potential for preparation of mushroom chitosan for application in the food, cosmetics, and pharmaceutical industries.

Ionic Conductivity and Structure of Chitosan Films Modified with Lactic Acid-Choline Chloride NADES.

The natural deep eutectic solvent (NADES) based on choline chloride (ChCl) and lactic acid (LA) was used for the preparation of chitosan (CS) films by the solution casting method. The content of NADES in films was from 0 to 82 wt%. The impact of NADES on the morphology and crystalline structure of films was investigated using scanning electron microscopy as well as wide-angle and small-angle X-ray scattering. The experimental results allow to propose CS chains swelling in NADES. FTIR spectroscopy confirms the interactions between CS and NADES components via the formation of hydrogen and ion bonds. The thermal properties of the composite films were studied by simultaneous thermogravimetric and differential thermal analysis. Thermomechanical analysis demonstrated appearance of two transitions at temperatures between −23 and −5 °C and 54–102 °C depending on NADES content. It was found that electrical conductivity of film with 82 wt% of NADES reaches 1.7 mS/cm. The influence of the composition and structure of films on the charge carriers concentration and their mobility is discussed.

Incorporation of chitosan/graphene oxide nanocomposite in to the PMMA bone cement: Physical, mechanical and biological evaluation

One of the most popular types of bone cements is polymethylmethacrylate (PMMA). The properties of this bone cement have attracted many researchers effort to modify its properties. In this study, after preparation of chitosan (Cs) powder and Cs/graphene oxide (GO) nanocomposite powder, they were added homogeneously to the PMMA bone cement with different percentages. The results showed that the addition of 25 wt% of Cs/GO nanocomposite powder to the PMMA bone cement cause to increase the compressive strength by 16.2%, the compressive modulus by 69.1% and the bending strength by 24.0%. The obtained results showed that by adding Cs/GO nanocomposite powder to the PMMA bone cement, setting time and injectability were increased, maximum temperature was decreased and apatite-like deposition was increased after 4 weeks of incubation in SBF solution. The results of MG-63 cell culture confirmed the improvement of cell viability, growth and cell adhesion for 25 wt% PMMA-Cs/GO composite bone cement. Therefore, it can be concluded that 25 wt% PMMA-Cs/GO composite bone cement with improved mechanical, physical and biological properties can be a good replacement for common commercial bone cements in orthopedic applications.

Preparation of chitosan and carboxymethylcellulose‐based polyelectrolyte complex hydrogel via SD‐A‐SGT method and its adsorption of anionic and cationic dye

AbstractThe excellent properties of the polyelectrolyte complex hydrogels (PECHs) prepared with polysaccharides only, including polyampholyte, low toxicity, green, and clean production, have endowed them great application potentials as the adsorbents for dye‐containing wastewater treatments. In the current study, the PECH of chitosan (CTS) and carboxymethylcellulose (CMC) was prepared by semi‐dissolution acidification sol–gel transition (SD‐A‐SGT) method. The hydrogel was formed by the strong electrostatic interaction of cationic NH3+ groups of CTS and the anionic COO− groups of CMC. This simple but efficient means exhibited great potentials in constructing PECHs with uniform composition and controllable sol–gel transitions. Molecular dynamics simulation was first employed to predict the formation process and the microstructure of PECHs prepared by SD‐A‐SGT method. The structure and properties of the CTS‐CMC PECHs were also characterized by Fourier transform infrared spectroscopy, SS 13C‐NMR, scanning electron microscopy, mechanical tests, and rheological measurements, respectively. Taking the advantage of amphoteric polyelectrolyte properties, adsorption properties of anionic and cationic dyes were investigated using sunset yellow FCF and methylene blue as model dyes, respectively. The PECHs prepared in the present work had good adsorption capacity for both cationic and anionic dyes with maximum adsorption capacity of 212.83 mg/g for sunset yellow FCF and 167.35 mg/g for methylene blue. Therefore, this PECH would be a promising environmentally friendly adsorbent for the treatment of functional molecules with different charges.