Ammonium Groups Of Chitosan Research Articles

Investigating the effect of chitosan’s degree of deacetylation on size of the nanoparticle

Chitosan (CS) is a naturalcationic polysaccharide obtained by deacetylation of chitin, a biopolymer found mainly in the exoskeleton of crab, shrimp shells, etc. The chitosan degree of deacetylation (DD) is an important factor which determines some of the physiochemical and biological properties of chitosan. The present study focuses on evaluating the effect of chitosan DD on nanoparticle size by using three different DD of chitosan, i.e., 85%, 90% and 93%. Chitosan nanoparticles were prepared by ionic gelation method using sodium tripolyphosphate (TPP) as crosslinker. The particle size and polydispersity index (PDI) was studied using Dynamic Light Scattering (DLS) and was further characterized by Fourier Transform Infrared spectroscopy (FTIR) to confirm the interactions between the ammonium groups of CS and tripolyphosphoric groups of TPP in the prepared nanoparticles. The results demonstrated that nanoparticles prepared using 85% DD chitosan had an average particle size of 100.2 ± 0.5 nm.

Synthesis and Properties of Chitosan- and Pectin-Based Hydrogels

Hydrogels have been prepared by mixing chitosan and pectin solutions, as well as solutions of their modified derivatives, in aqueous media at room temperature. The gels are obtained within a time period from several seconds to half an hour or more, depending on the process conditions. The hydrogels are formed due to both the covalent bonding between functional groups and the formation of interpolyelectrolyte complexes via the interaction between ammonium groups of chitosan and carboxylate groups of pectin. Conditions have been determined for the hydrogel formation throughout the solution volume without liquid phase separation. The swelling of lyophilized hydrogels has been studied as depending on the ionic strength and pH of aqueous media. The feasibility of prolonged drug release from the developed polymer matrix has been shown by the example of cytostatics, namely, mitomycin C and cisplatin.

Characterization of alginate-chitosan membrane as potential edible film

Alginate-chitosan based biopolymer for possible application as edible film coating has been studied. Alginate hydrosol and chitosan hydrosol with mass ratio of 1:1 were mixed to form a thin membrane and then dried. The obtained alginate-chitosan membrane was confirmed using FTIR spectrophotometers. Characterization of the membrane, which includes thickness, tensile strength, water vapor sorption, resistance to pH change and antimicrobials properties, were conducted. It was showed that the interaction of alginate and chitosan in the membrane occurred through the electrostatic interaction of the carboxylic group of alginate and ammonium groups of chitosan. At the same thickness, the alginate-chitosan membrane tensile strength was higher and more resistant to pH changes than both native alginate and chitosan membranes. Furthermore, the alginate-chitosan membrane has good antibacterial potential against gram-positive bacteria (Staphylococcus aureus) and gram-negative bacteria (Escherichia coli). It is expected that the alginate-chitosan membrane has the potential application for safe and efficient fruit coating.

Suitability of chitosan nanoparticles as cryoprotectant on shelf life of restructured fish surimi during chilled storage

The present study investigated chitosan nanoparticle (CS-TPP NPs) preparation by ionic gelation process with chitosan (CS) and tripolyphosphate (TPP). The structural characterization of nanoparticles was studied using Dynamic Light Scattering, Nuclear Magnetic Resonance, Fourier Transform Infrared (FTIR) and X-Ray Diffraction spectroscopies. FTIR spectra confirmed that the tripolyphosphoric groups of TPP linked with ammonium groups of CS in the prepared nanoparticles. CS-TPP NPs exhibited higher antioxidant activity and an interesting antimicrobial potential. In fact, there was no report available in literature on using CS nanoparticles for the surimi preservation. Further, data revealed that nanoparticle incorporation in fish surimi effectively inhibited thiobarbituric acid substances and conjugated dienes formation, and thereby, retarding lipid oxidation. Results showed that CS-TPP NPs were able to hinder fish surimi myoglobin oxidation with a significant improvement in the transformation of Heme iron. In addition, CS nanoparticles exhibited a distinguishable antimicrobial activity in the stored surimi during cold storage of 9 days. Thus, nanoparticles could be used as a natural ingredient to prevent lipid oxidation in surimi based food systems for the development of novel healthy fish products and addresses consumer demands for functional fish products.

Formulation and corneal permeation of ketorolac tromethamine-loaded chitosan nanoparticles

The aim of this work was to formulate chitosan (CS)-based nanoparticles (NPs) loaded with ketorolac tromethamine (KT) intended for topical ocular delivery. NPs were prepared using ionic gelation method incorporating tri-polyphosphate (TPP) as cross-linker. Following the preparation, the composition of the system was optimized in terms of their particle size, zeta potential, entrapment efficiency (EE) and morphology, as well as performing structural characterization studies using Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). The data suggested that the size of the NPs was affected by CS/TPP ratio where the diameter of the NPs ranged from 108.0 ± 2.4 nm to 257.2 ± 18.6 nm. A correlation between drug EE and the corresponding drug concentration added to the formulation was observed, where the EE of the NPs increased with increasing drug concentration, for up to 10 mg/mL. FT-IR and DSC revealed that KT was dispersed within the NPs where the phosphate groups of TPP were associated with the ammonium groups of CS. The in vitro release profile of KT from CS NPs showed significant differences (p < 0.05) compared to KT solution. Furthermore, mucoadhesion studies revealed adhesive properties of the formulated NPs. The KT-loaded NPs were found to be stable when stored at different storage conditions for a period of 3 months. The ex vivo corneal permeation studies performed on excised porcine eye balls confirmed the ability of NPs in retaining the drug on the eye surface for a relatively longer time. These results demonstrate the potential of CS-based NPs for the ocular delivery of KT.

Preparation and in vitro characterization of chitosan nanoparticles containing Mesobuthus eupeus scorpion venom as an antigen delivery system

Hydrophilic nanoparticles have been widely investigated in recent years as delivery systems for therapeutic macromolecules such as antigens. In the present study Mesobuthus eupeus venom-loaded chitosan nanoparticles were prepared via ionic gelation of tripolyphosphate (TPP) and chitosan. The optimum encapsulation efficiency (91.1%) and loading capacity (76.3%) were obtained by a chitosan concentration of 2 mg/mL, chitosan-to-TPP mass ratio of 2 and M. eupeus venom concentration of 500 µg/mL. The average nanoparticle size at optimum conditions was determined by Zetasizer (Malvern Instruments, UK). The nanoparticle size was about 370 nm (polydispersity index: 0.429) while the zeta potential was positive. Transmission electron microscope (TEM) imaging showed a spherical, smooth and almost homogenous structure for nanoparticles. Fourier transform infrared (FTIR) spectroscopy confirmed tripolyphosphoric groups of TPP linked with ammonium groups of chitosan in the nanoparticles. The in vitro release of nanoparticles showed an initial burst release of approximately 60% in the first ten hours, followed by a slow and much reduced additional release for about 60 hours. It is suggested that the chitosan nanoparticles fabricated in our study may provide a suitable alternative to traditional adjuvant systems.

Thermal Treatment Effects on Biopolymer Multilayered Thin Films

Sterilization is very important for the use of biomaterials in the medical field. This work describes the preparation of chitosan/carboxymethylcellulose thin films with the layer-by-layer deposition technique, and the investigation on the effects that thermal treatments have on them during sterilization. The influence of different heating and sterilization methods on the chemical and physical structure of biopolymer thin films composed of chitosan and carboxymethylcellulose was evaluated. Films were heated in an oven at specified temperatures or autoclaved and their characteristics analyzed with contact angle, profilometry, FTIR, anionic dye uptake and UV-Vis measurements. Results show that, depending on the heating conditions, these thin films may undergo the Maillard reaction that turns the films from being transparent to brownish in color. This reaction may lead to a decrease in the free hydroxyl groups of both carboxymethylcellulose and chitosan and free ammonium groups of chitosan - consequently leading to changes in hydrophilicity and wettability of the film. Temperature effects on the characteristics of the synthetic pre-layer coating composed of poly (diallyldimethylammonium chloride) and poly (sodium 4-styrene-sulfonate) - used to provide a high cationic surface for the deposition of the biopolymer films - were also observed. These findings are of practical interest because biopolymer thin films find a great number of applications where sterilization is a must, such as clinical and medical applications and in the areas of materials science and biotechnology.

The Preparation and Characteristics on Chitosan Nano-Carrier with Different Concentration of TPP

In this Study, the Tripolyphosphate-Chitosan (TPP-CS) Nano-Carrier was Prepared by Polyelectrolyte Complexation. TPP and CKGM are Polyanion, and can Interact with Cationic Chitosan by Electrostatic Forces. the Nanoparticles Size was Analyzed by the Transmission Electron Micrographs (TEM) and Scattering Electron Micrographs (SEM). FTIR Confirmed Tripolyphosphoric Groups of TPP and CKGM Linked with Ammonium Groups of Chitosan in the Nanoparticles. the CS Nps were Loaded with the Anticancer Drug, Berberine, by Different Concentration of Cross-Linking Agent. the Zeta Potentials of CKGM and CS were Shown as a Function of Ph. it was Observed that CS has Strong Interaction with CKGM about Ph 5.5. the CKGM-CS Nanoparticles were Formed by Mixed Different Weight Ratio of CS and CKGM. the Morphology of CKGM-CS was Characterized by FESEM. the Size of CKGM-CS Particles was Smaller than 150 Nm. the Zeta Potential of CKGM-CS Particles was Proved that the Polymer Ratio can Control the Charge Density.

Designing a Highly Efficient Chemical Chaperone System Using Chitosan-Coated Alginate

In the present work we prepared chitosan-coated alginate beads, to use as a chemical chaperone based on the electrostatic interaction between the carboxylate groups of alginate and the ammonium groups of chitosan. This procedure was an attempt for designing a highly efficient chemical chaperone to improve protein stability and refolding. Based on enzyme recovered activity, turbidity, far-UV CD and fluorescence data, alkaline phosphatase can be stabilized and refolded to a higher degree in the presence of alginate capsules compared with unassisted form and was further improved by including chitosan. Finally the maximum yield was obtained when the refolding process was achieved under a well worked out temperature program: incubation of the captured-enzyme for 20 min at 4 degrees C followed by overnight incubation at 22 degrees C, which showed that aggregation is a major limitation to refolding.

Biobased Nanocomposites from Layer-by-Layer Assembly of Cellulose Nanowhiskers with Chitosan

A new biodegradable nanocomposite was obtained from layer-by-layer (LBL) technique using highly deacetylated chitosan and eucalyptus wood cellulose nanowhiskers (CNWs). Hydrogen bonds and electrostatic interactions between the negatively charged sulfate groups on the whisker surface and the ammonium groups of chitosan were the driving forces for the growth of the multilayered films. The film growth was followed by UV-vis spectroscopy through the maximum value of the absorption band at 194 nm and showed the deposition of 14.7 mg.m(-2) of chitosan polymer in each cycle. Scanning electron microscopy showed high density and homogeneous distribution of CNWs adsorbed on each chitosan layer. Cross-section characterization of the assembled films indicates an average of approximately 7 nm of thickness per bilayer. The results presented in this work indicate that the methodology used can be extended to different biopolymers for the design of new biobased nanocomposites in a wide range of applications such as biomedical and food packaging.

Low water swelling and high methanol resistant proton exchange membrane fabricated by cross-linking of multilayered polyelectrolyte complexes

Multilayered polyelectrolyte complexes (PECs) modified proton exchange membranes are successfully prepared from alternating deposition of oppositely charged polyelectrolyte chitosan (CS) and sulfonated poly (aryl ether ketone) bearing carboxyl groups (SPAEK-C) on the surface of Nafion ®117 via the layer-by-layer (LBL) method. The cross-linked PEC-coated Nafion ® membranes (c-PEC-coated Nafion ® membranes) are prepared from heat-induced cross-linking between CS and SPAEK-C via formation of amide bonds. Fourier transform infrared spectroscopy (FT-IR) verifies that cross-linking between ammonium groups of CS and carboxyl groups of SPAEK-C occurs by the formation of amide bonds. The morphology of the membranes is studied in detail by SEM. The c-PEC-coated Nafion ® membranes exhibit low water uptake (23.5%, 80 °C), water swelling (14.0%, 80 °C) and methanol permeability (2.7 × 10 −7 cm 2 s −1). Proton conductivity of the c-PEC-coated Nafion ® membranes increase at elevated temperature, reaching the value of 0.131 S cm −1 at 80 °C. These results show that cross-linking of layered CS/SPAEK-C films can effectively reduce water uptake, water swelling and methanol permeability while improve the dimensional stability and maintain high proton conductivity.

Preparation of chitosan nanoparticles containing Naja naja oxiana snake venom

Hydrophilic nanoparticles have received much attention for delivery of therapeutic peptides, proteins, and antigens. Chitosan (CS) is a biodegradable and nontoxic polysaccharide, as a carrier for drug delivery. The study purpose was to evaluate the influence of a number of factors on the encapsulation of Naja naja oxiana (Indian or speckled cobra) venom and loading capacity, as well as to investigate the physicochemical structure of nanoparticles. CS nanoparticles were produced based on the ionic gelation process of tripolyphosphate (TPP) and CS. All the preparations were estimated with diameter 120–150 nm and spherical shape using transmission electron microscopy. Fourier transform–infrared spectroscopy confirmed that tripolyphosphoric groups of TPP linked with ammonium groups of CS in the nanoparticles. Our results showed that CS can react with TPP to form stable cationic nanoparticles. Therefore, when chitosan concentration was increased to 1.5 mg/mL the aggregates with large diameter were formed. Optimum loading capacity and encapsulation efficiency of venom at a concentration of 500 μg/mL were achieved for low-molecular-weight (low-MW) CS at a concentration of 2 mg/mL and high-MW CS at a concentration of 3 mg/mL. From the Clinical Editor In this study a hydrophilic nanoparticle chitosan was investigated as a protein delivery system, and optimum conditions were established for future use of this technology.

Development and In Vitro Evaluation of Alginate Gel–Encapsulated, Chitosan-Coated Ceramic Nanocores for Oral Delivery of Enzyme

The successful administration of protein and peptide drugs by oral route maintaining their active conformation remains a key challenge in the field of pharmaceutical technology. In the present study, we propose the use of a nanosize ceramic core-based system for effective oral delivery of acid-labile model enzyme, serratiopeptidase (STP). Ceramic core was prepared by colloidal precipitation and sonication of disodium hydrogen phosphate solution and calcium chloride solution at room temperature. The core was coated with chitosan under constant stirring and Fourier-Transform Infra Red Spectroscopy (FTIR) confirmed phosphoric groups of calcium phosphate linked with ammonium groups of chitosan in the nanoparticles; then the enzyme was adsorbed over the preformed nanocore. Protein-loaded nanocore was further encapsulated into alginate gel for enzyme protection. Prepared system was characterized for size, shape, loading efficiency, and in vitro release profile (pH 1.2 and pH 7.4). The effect of processing variables on the size of the core was evaluated to form small, uniform, and discrete nanocores. Stability and integrity of enzyme during processing steps was assessed by in vitro proteolytic activity. The prepared system was examined to be spherical in shape with diameter 925 ± 6.81 nm using TEM. The in vitro release data followed the Higuchi model, showing a low amount (26% ± 2.4%) of diffusion-controlled drug release (R2 = 0.9429) in acidic buffer up to a period of 2 to 6 hours, signifying the integrity of alginate gel in acid. In the alkaline medium sustained and nearly complete first order release of protein was observed up to a 6 hours. It is inferred that the protein-loaded ceramic core acts as a reservoir of the adsorbed enzyme and alginate gel provides protection to STP for controlled release in intestinal pH when compared to the enzyme solution.

Effect of molecular structure of chitosan on protein delivery properties of chitosan nanoparticles

Chitosan nanoparticles (CS NP) with various formations were produced based on ionic gelation process of tripolyphosphate (TPP) and chitosan. They were examined with diameter 20–200 nm and spherical shape using TEM. FTIR confirmed tripolyphosphoric groups of TPP linked with ammonium groups of chitosan in the nanoparticles. Factors affecting delivery properties of bovine serum albumin (BSA) as model protein have been tested, they included molecular weight (Mw) and deacetylation degree (DD) of chitosan, the concentration of chitosan and initial BSA, and the presence of polyethylene glycol (PEG) in encapsulation medium. Increasing Mws of chitosan from 10 to 210 kDa, BSA encapsulation efficiency was enhanced about two times, BSA total release in PBS (phosphate buffer saline) pH 7.4 in 8 days was reduced from 73.9 to 17.6%. Increasing DD from 75.5 to 92% promoted slightly the encapsulation efficiency and decelerated the release rate. The encapsulation efficiency was highly decreased by increase of initial BSA and chitosan concentration; higher loading capacity of BSA speeded the BSA release from the nanoparticles. Adding PEG hindered the BSA encapsulation and accelerated the release rate.