Chitosan Base Research Articles

Experimental assessment of efficiency of new domestic local haemostatic means on the basis of chitosan

One of the main reasons for the death of potentially wounded military personnel on the battlefield is ongoing bleeding. In recent years, with the advent of a new group of local hemostatic drugs, the results of prehospital care with external massive bleeding have improved significantly. At the same time, local haemostatic agents based on chitosan showed the greatest effectiveness. The results of the experimental evaluation of the effectiveness of new local haemostatic agents based on chitosan: «Gemohit» (powder, 20 g in the package) and «Hemohit-bandage» (a bandage in the z-fold, 8×150 cm) using the model of external massive arterial bleeding in sheep according to the variant of marginal femoral artery injury. Some of the tests were carried out after 3 years of storage of the preparations (3 samples) and under ambient conditions minus45°C (2 tests). It was found that with external massive arterial bleeding, the use of powder and bandage in the z-fold ensured survival of the animals in 100% of cases, primary and final hemostasis was achieved in 50 and 100% of cases, respectively. Storage for 3 years, as well as use of the drug at low ambient temperature does not reduce its effectiveness. The use of local haemostatic agents «Gemohit» and «Hemohit-bandage» is not accompanied by side effects (local hyperthermal reaction, distal or proximal embolism of blood vessels). Local haemostatic funds «Gemohit» and «Gemohit-bint» showed high efficiency in the experimental model of massive external arterial bleeding. Using the local hemostatic agent «Gemohit» in the form of a bandage is more promising in terms of convenience and effectiveness than the use of powder.

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

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

Simultaneous wastewater treatment and bioelectricity production in microbial fuel cells using cross-linked chitosan-graphene oxide mixed-matrix membranes.

Microbial fuel cells (MFCs) are emerging technology for wastewater treatment by chemical oxygen demand (COD) reduction and simultaneous bioelectricity production. Fabrication of an effective proton exchange membrane (PEM) is a vital component for MFC performance. In this work, green chitosan-based (CS) PEMs were fabricated with graphene oxide (GO) as filler material (CS-GO) and cross-linked with phosphoric acid (CS-GO-P(24)) or sulfuric acid (CS-GO-S(24)) to determine their effect on PEM properties. Interrogation of the physicochemical, thermal, and mechanical properties of the cross-linked CS-GO PEMs demonstrated that ionic cross-linking based on the incorporation of PO43- groups in the CS-GO mixed-matrix composites, when compared with sulfuric acid cross-linking commonly used in proton exchange membrane fuel cell (PEMFC) studies, generated additional density of ionic cluster domains, rendered enhanced sorption properties, and augmented the thermal and mechanical stability of the composite structure. Consequently, bioelectricity performance analysis in MFC application showed that CS-GO-P(24) membrane produced 135% higher power density than the CS-GO-S(24) MFC system. Simultaneously, 89.52% COD removal of primary clarifier municipal wastewater was achieved in the MFC operated with the CS-GO-P(24) membrane.

Experimental evaluation of the effectiveness of wound dressings based on biologically active substances from marine hydrobionts

This article presents the experimental data on the testing of new wound dressings, viz., porous plates, prepared on the basis of chitosan and calcium alginate that contain biologically active substances (BASs) derived from marine hydrobionts. In a burn wound model in guinea pigs, we revealed a positive effect of tested samples of wound dressings on the wound-healing process; the data of planimetric and pathomorphological studies showing the acceleration of the process of regeneration in the wound are discussed. It was noted that the dynamics and patomorphological characteristics of the wound healing process differed depending on the structure of the BAS included into the composition of wound dressings (peptides, sulfated polysaccharides, a complex of amino acids and peptides).

Hemocompatibility of ultrafine systems on the basis of chitosan and its derivatives polymercolloid complexes

Hemocompatibility of ultrafine systems on the basis of chitosan and its derivatives polymercolloid complexes

From crab shells to smart systems: chitosan-alkylethoxy carboxylate complexes.

In this work, self-assembly of alkyl ethylene oxide carboxylates and the biopolymer chitosan into supramolecular structures with various shapes is presented. Our investigations were done at pH 4.0, where the chitosan is almost fully charged and the surfactants are partially deprotonated. By changing the alkyl chain length and the number of ethylenoxide units very different water-soluble complexes can be obtained, ranging from globular micelles incorporated in a chitosan network to formation of ordered multiwalled vesicles. The structural characteristics of these complexes can be finely controlled by the mixing ratio of chitosan and surfactant, i.e., simply by the solutions composition. For instance, the vesicle wall thickness can be varied between 5 and 50 nm just by varying the mixing ratio. Accordingly, we expect this system to be an outstanding carrier for hydrophilic compounds with tunable release time option. Moreover, an easy route for preparation of chitosan-based complexes in the solid state with controlled mesoscopic order is presented. This work opens the way to prepare biofriendly materials on the basis of chitosan and mild anionic surfactants which are rather versatile with respect to their structure and properties, allowing for preparation of complexes with highly variable structures in both aqueous and solid phase. Formation of such different structures can be exploited for preparation of carriers, which are able to transport hydrophilic as well as hydrophobic molecules. Furthermore, as chitosan is well known to exhibit antibacterial and anti-inflammatory properties, different applications of these complexes can be indicated, i.e., as drug delivery systems or as coatings for medical implants.

Tetracycline release from chitosan/fish‐scale‐based membranes

ABSTRACTIn this study, we aimed to develop new biocompatible membranes on the basis of chitosan (CHIT) and fish scale powder (ESC) from the species Leporinus elongatus. The possibility of using the uncrosslinked membrane (ESC/CHIT) and membrane crosslinked with sodium tetraborate (ESC/CHIT‐B) for tetracycline release was investigated. The drug‐release kinetics were studied at 30 and 37°C in phosphate buffered saline (pH 7.4). For ESC/CHIT, the drug release was faster, about 6 days, whereas the release time of tetracycline impregnated in ESC/CHIT‐B was about 7 days. The in vitro release behavior of tetracycline from both membranes followed the Peppas and Higuchi kinetic models. The kinetics of drug release from ESC/CHIT were regarded as a coupled diffusion/polymer relaxation mechanism, whereas drug release from ESC/CHIT‐B seemed to be controlled by polymer relaxation. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 39943.

Burn-Healing Effects of a Composition Containing Chitosan Gel and a Blood Serum Bioregulator

We studied the effect of combined preparation on the basis of chitosan containing a bioregulator isolated from cattle serum in a concentration of 10(-10) mg/ml on healing of II-IIIa degree skin burns in mammals in vivo.

Simple, Reversible Emulsion System Switched by pH on the Basis of Chitosan without Any Hydrophobic Modification

Chitosan without hydrophobic modification is not a good emulsifier itself. However, it has a pH-tunable sol-gel transition due to free amino groups along its backbone. In the present work, a simple reversible Pickering emulsion system based on the pH-tunable sol-gel transition of chitosan was developed. At pH > 6.0, as adjusted by NaOH, chitosan was insoluble in water. Chitosan nanoparticles or micrometer-sized floccular precipitates were formed in situ. These chitosan aggregates could adsorb at the interface of oil and water to stabilize the o/w emulsions, so-called Pickering emulsions. At pH < 6.0, as adjusted by HCl, chitosan was soluble in water. Demulsification happened. Four organic solvents (liquid paraffin, n-hexane, toluene, and dichloromethane) were chosen as the oil phase. Reversible emulsions were formed for all four oils. Chitosan-based Pickering emulsions could undergo five cycles of emulsification-demulsification with only a slight increase in the emulsion droplet size. They also had good long-term stability for more than 2 months. Herein, we give an example of chitosan without any hydrophobic modification to act as an effective emulsifier for various oil-water systems. From the results, we have determined that natural polymers with a stimulus-responsive sol-gel transition should be a good particulate emulsifier. The method for in situ formation of pH-responsive Pickering emulsions based on chitosan will open up a new route to the preparation of a wide range of reversible emulsions.

Effect of a Composition Containing Chitosan Gel and a Bioregulator from Blood Serum on Healing of Purulent Wounds in Mice

We studied the effect of combined preparation on the basis of chitosan containing a bioregulator isolated from cattle serum in a concentration of 10(-10) mg/ml on healing of purulent wounds in mammals in vivo.

Production of composite biomaterials for medical application on the basis of chitosan from Blakeslea trispora industrial waste

Production of composite biomaterials for medical application on the basis of chitosan from Blakeslea trispora industrial waste

Facile synthesis of Ag and Au nanoparticles utilizing chitosan as a mediator agent

We present here a facile route for the synthesis of crystal Ag and Au nanoparticles on the basis of chitosan as a mediator agent under quiescent conditions. The resulting Ag nanoparticles displayed controllable structural and optical properties depending on the experimental parameters. Fourier transform infrared (FTIR) study combined with zeta potential measurement disclosed that the amino groups were bound to the particles, which was accountable for the stability of nanoparticles. The Ag and Au nanoparticles prepared in our present method is a promising candidate for applications in catalysis, antimicrobial and surface-enhanced Raman scattering.

Chitosan and its derivatives in extensional and shear flows

Allylchitosan and propylchitosan with different degrees of substitution were prepared on the basis of chitosan from shrimp chitin. The dynamics of semidilute electrolytic polymer solutions of chitosan derivatives in acetic acid was studied by measuring birefringence in extensional and shear flows and by means of viscometry. The optical shear coefficient and critical velocity gradients corresponding to the loss of stability of the macromolecular coil in extensional flow were found. The chain relaxation times depending on the polyelectrolyte concentration and ionic strength of solution were determined.

Removal of heavy metal from industrial wastewater using chitosan coated oil palm shell charcoal

This research focuses on understanding biosorption process and developing a cost effective technology for treatment of heavy metals-contaminated industrial wastewater. A new composite biosorbent has been prepared by coating chitosan onto acid treated oil palm shell charcoal (AOPSC). Chitosan loading on the AOPSC support is about 21% by weight. The shape of the adsorbent is nearly spherical with particle diameter ranging 100~150 µm. The adsorption capacity of the composite biosorbent was evaluated by measuring the extent of adsorption of chromium metal ions from water under equilibrium conditions at 25oC. Using Langmuir isotherm model, the equilibrium data yielded the following ultimate capacity values for the coated biosorbent on a per gram basis of chitosan: 154 mg Cr/g. Bioconversion of Cr (VI) to Cr (III) by chitosan was also observed and had been shown previously in other studies using plant tissues and mineral surfaces. After the biosorbent was saturated with the metal ions, the adsorbent was regenerated with 0.1 M sodium hydroxide. Maximum desorption of the metal takes place within 5 bed volumes while complete desorption occurs within 10 bed volumes. Details of preparation of the biosorbent, characterization, and adsorption studies are presented. Dominant sorption mechanisms are ionic interactions and complexation.

Adsorption of Chromium(VI) on Chitosan‐Coated Perlite

Chitosan‐coated perlite beads were prepared by drop‐wise addition of a liquid slurry containing chitosan and perlite to an alkaline bath. The beads were characterized by SEM and EDS x‐ray microanalysis. The chitosan content of the beads was 23%, as determined by a pyrolysis method. Adsorption of hexavalent chromium from aqueous solutions on chitosan‐coated perlite beads was studied under both equilibrium and dynamic conditions. The effect of pH on adsorption was also investigated. The data were fitted to the Langmuir adsorption isotherm. The adsorption capacity of chitosan‐coated perlite was found to be 104 mg/g of adsorbent from a solution containing 5000 ppm of Cr(VI). On the basis of chitosan, the capacity was 452 mg/g of chitosan. The capacity was considerably higher than that of chitosan in its natural and modified forms, which was in the range of 11.3 to 78 mg/g of chitosan. The beads loaded with chromium were regenerated with sodium hydroxide solution of different concentrations. A limited number of adsorption‐desorption cycles indicated that the chitosan‐coated beads could be regenerated and reused to remove Cr(VI) from waste streams.