Chitosan Polyelectrolyte Complex Research Articles

Антимікробна та противірусна активність нанокомпозитів на основі поліелектролітних комплексів з наночастинками срібла

Recently, nanocomposite materials containing nanoparticles of metals such as silver, copper and zinc oxide have attracted most attention due to their pronounced pharmacological properties, such as antimicrobial, antiviral, antiinflammatory, immunomodulatory ability and high stability in extreme conditions. Polyelectrolyte complexes based on polymers of natural origin, namely polysaccharides of chitosan and pectin, which can stabilize nanoparticles of a smaller size than individual polymers have significant potential for creation of silver-containing nanocomposites. The aim of this article is to study the antimicrobial and antiviral activity of silver-containing nanocomposites based on polyelectrolyte complexes. Methods. Peculiarities of the structural organization of silver-containing nanocomposites were investigated by the method of wide-angle scattering on an XRD-7000 diffractometer. The morphology of Ag nanoparticles in polymer matrixes were studied by transmission electron microscopy method (transmission electron microscope JEOL 100 CXII). The antimicrobial activity of silver-containing nanocomposites was determined by agar diffusion assays against opportunistic pathogens Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. Cytotoxicity and antiviral activity were investigated using the MTT method and staining by gentian violet. Results. Analysis of wide-angle X-ray diffractograms of silver-containing nanocomposites based on polyelectrolyte complexes Na-CMC (pectin) – chitosan showed that at reduction of Ag+ ions to metallic silver, there are two low-intensity diffraction maxima at 2θm ~ 380 and 440 in the diffractograms. These maxima correspond to the crystallographic planes of the face-centered cubic lattice of silver, are characterized by indices (111) and (200), respectively, and confirm the presence of metallic silver in the polymer system. Analysis of micrographs of silver-containing nanocomposites based on Na-CMC and chitosan showed that larger nanoparticles are formed with increasing the molecular weight of chitosan. The dependence of the size of silver nanoparticles on the wavelength of ultraviolet radiation at reduction of silver ion in polyelectrolyte-metal complexes Na-CMC–Ag+–chitosan of low molecular weight was also revealed. In particular, smaller particles are formed under irradiation by light with a shorter wavelength (λ =254 nm) than at λ=365 nm. Silver-containing nanocomposites Na-СMC-Ag-chitosan and pectin citrus-Ag-chitosan, obtained by reduction of Ag+ ions under ultraviolet irradiation at a wavelength λ = 365 nm and λ = 254 nm, exhibit high antimicrobial activity against the test cultures of microorganisms S. aureus, E. coli, and P. aeruginosa C. albicans. No significant dependence of antimicrobial activity on the molecular weight of the studied samples was noted: the obtained data were within close limits and had close values. In addition, no dependence of antimicrobial activity on the type of investigated test cultures of microorganisms was observed either. Nanocomposites based on Na-CMC-chitosan (λ = 365 nm) inhibited infection titer HSV-1 by (3.72–5.45) lgTCID50/mL, whereas the decrease in titer during incubation with samples based on citrus pectin-chitosan was within (2.39–2.42) lgTCID50/mL. A dose-dependent relationship between molecular weight of chitosan and reduction of infection titer was observed. It was found that silver-containing nanocomposites formed by reduction of silver ions in polyelectrolyte-metal complexes under ultraviolet radiation of different wavelengths had no cytotoxic effect on cells of MDCK and BHK. Conclusions. The investigated silver-containing nanocomposites based on Na-CMC (pectin)-chitosan polyelectrolyte complexes show antimicrobial activity against test cultures of S. aureus, E. coli P. aeruginosa, and C. albicans along with antiviral activity against herpes simplex virus type 1 and influenza virus. It was established that the obtained nanocomposites did not show a cytotoxic effect on MDCK and BHK cells. The obtained data allow us to assert that investigated silver-containing nanocomposites are promising antimicrobial means for the development of new effective strategies against microorganisms and viruses and improvement of the population health.

Polyphosphate–Chitosan Polyelectrolyte Complexation

The literature on complexation between chitosan and sodium polyphosphates is limited to very short polyphosphates with degrees of polymerization of 2 to 6. Here, for the first time, polyelectrolyte complexation between chitosan and moderately long (Dp = 22) polyphosphates was studied. Using turbidity measurements, optical microscopy, and visual observations the phase diagram of the system was determined and compared to a traditionally deployed tripolyphosphate system. Such diagrams are rare but could be important to anticipate the products of a reaction of specific polyelectrolyte pairs. It was shown that this chitosan-polyphosphate system is not capable of forming coacervates and is therefore more appropriate for developing solid rather than liquid biomaterial precursors.

Additive manufacturing of wet-spun chitosan/hyaluronic acid scaffolds for biomedical applications

Additive manufacturing (AM) holds great potential for processing natural polymer hydrogels into 3D scaffolds exploitable for tissue engineering and in vitro tissue modelling. The aim of this research activity was to assess the suitability of computer-aided wet-spinning (CAWS) for AM of hyaluronic acid (HA)/chitosan (Cs) polyelectrolyte complex (PEC) hydrogels. A post-printing treatment based on HA chemical cross-linking via transesterification with poly(methyl vinyl ether-alt-maleic acid) (PMVEMA) was investigated to enhance the structural stability of the developed scaffolds in physiological conditions. PEC formation and the esterification reaction were investigated by infrared spectroscopy, thermogravimetric analysis, evolved gas analysis-mass spectrometry, and differential scanning calorimetry measurements. In addition, variation of PMVEMA concentration in the cross-linking medium was demonstrated to strongly influence scaffold water uptake and its stability in phosphate buffer saline at 37 °C. The in vitro cytocompatibility of the developed hydrogels was demonstrated by employing the murine embryo fibroblast Balb/3T3 clone A31 cell line, highlighting that PMVEMA cross-linking improved scaffold cell colonization. The results achieved demonstrated that the developed hydrogels represent suitable 3D scaffolds for long term cell culture experiments.

Polyelectrolyte Complexation of Chitosan and WS2 Nanotubes

AbstractThe inclusion of tungsten disulphide nanotubes (WS2 NTs) in chitosan, plasticized with glycerol, facilitates the formation of a polyelectrolyte complex. The glycerol interrupts the intramolecular hydrogen bonding between chitosan chains allowing positively charged protonated amines of chitosan to form a complex with negatively charged oxygen ions chemisorbed to the tungsten atoms in defects. These interactions, with the unique mechanical and chemical properties of WS2 NTs, result in a chitosan film with superior properties relative to unfilled chitosan. Even at low WS2 NT loadings (≤1 wt%), the Young's modulus (E) increases by 59%, tensile strength (σ) by 40% and tensile toughness by 74%, compared to neat chitosan, without sacrificing ductility. Addition of highly dispersed WS2 NTs significantly improves the gas barrier properties of chitosan, with a 50% reduction in oxygen permeability, while the addition of both glycerol and WS2 NTs to chitosan effectively reduces the carbon dioxide permeability by 80% and the water vapor transmission rate by 90%. The intrinsic antimicrobial efficacy of chitosan against both Gram‐positive and Gram‐negative bacteria is enhanced on inclusion of WS2 NTs. Polyelectrolyte complexation of WS2 NTs and glycerol‐plasticized chitosan provides a cost‐effective, sustainable route to biodegradable films with desirable mechanical, gas barrier properties, and antimicrobial efficacy suitable for food packaging applications.

Alginate–Chitosan Polyelectrolyte Complexes As Carriers for Fluorinated Tetraphenylporphyrin in Photosensitizing Systems of Singlet Oxygen Generation

Alginate–Chitosan Polyelectrolyte Complexes As Carriers for Fluorinated Tetraphenylporphyrin in Photosensitizing Systems of Singlet Oxygen Generation

Alginate–Chitosan Polyelectrolyte Complexes As Carriers for Fluorinated Tetraphenylporphyrin in Photosensitizing Systems of Singlet Oxygen Generation

Alginate–Chitosan Polyelectrolyte Complexes As Carriers for Fluorinated Tetraphenylporphyrin in Photosensitizing Systems of Singlet Oxygen Generation

Electrochemical Synthesis of Hybrid Materials Based on Polyelectrolyte Complexes of Chitosan and Their Physicochemical Properties

Electrochemical Synthesis of Hybrid Materials Based on Polyelectrolyte Complexes of Chitosan and Their Physicochemical Properties

ELECTROCHEMICAL SYNTHESIS OF HYBRID MATERIALS BASED ON POLYELECTROLYTE CHITOSAN COMPLEXES AND INVESTIGATION OF THEIR PHYSICAL AND CHEMICAL PROPERTIES

A study of the morphology, structure and elemental composition of hybrid materials on the surface of stainless steel based on polyelectrolyte complexes of chitosan with cobalt and nickel oxides, obtained using an alternating asymmetric current, was carried out. It was established by X-ray phase analysis that the main phase of the obtained hybrid materials is cobalt hydroxyisocyanate. The prospects of using the obtained hybrid materials as electrodes for supercapacitors with alkaline electrolyte are shown, while its specific capacitance at a current density of 1 A∙g-1 reaches 479 F∙g-1. The antibacterial activity of hybrid materials against gram-positive (S.aureus) and gram-negative (E.coli) microorganisms was determined. A study of corrosion-protective properties of the developed hybrid materials in a solution of 3.5 wt. % NaCl was carried out, it is shown that for the hybrid material the corrosion potential is shifted to the region of positive values compared to pure steel.

Green and Scalable Biopolymer‐Based Aqueous Polyelectrolyte Complexes for Zinc‐Ion Charge Storage Devices

AbstractGreen and scalable materials are essential to fulfill the need of electrification for transitioning into a fossil‐fuels free society, and sustainability is a requirement for all new technologies. Rechargeable batteries are one of the most important elements for electrification, enabling the transition to mobile electronics, electrical vehicles and grid storage. We here report synthesis and characterization of polyelectrolyte complexes of alginate and chitosan, both biopolymers deriving from the sea, for transport of zinc ions in hydrogel electrolytes. We have used vibrational spectroscopy, thermal measurements and microscopy, as well as transport measurements with ohmic or blocking contacts. The transference number for zinc ions is close to 1, the conductivity is ≈10 mS/cm, with stability at Zn interfaces seen through 7000 cycles in symmetric zinc//zinc cell.

A novel hybrid electrode materials for supercapacitors based on polyelectrolyte chitosan complex

In this work, hybrid materials based on polyelectrolyte complexes of chitosan with cobalt and nickel oxycompounds on the stainless steel surface were obtained using the non-stationary electrolysis method. Morphology, structure and elemental composition of the hybrid materials were studied. The X-ray phase analysis method allowed us to find that the main phase of the obtained hybrid materials is cobalt hydroxyisocyanate Co(OCN)0.6(OH)1.4(H2O)0.6. The electrochemical characteristics of the hybrid materials obtained were studied by cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) in an alkaline electrolyte. The specific capacitance was 479 F∙g−1 at the current density of 1 A∙g−1. The calculated energy density and power density of the cell was 0.055 W∙h∙kg−1 and 116 W∙kg−1, respectively. The results of long-term cycling allow us to conclude that the hybrid material is characterized by sufficient stability with capacity retention up to 85% after 5000 cycles.

A Voltammetric Sensor Based on Aluminophosphate Zeolite and a Composite of Betulinic Acid with a Chitosan Polyelectrolyte Complex for the Identification and Determination of Naproxen Enantiomers

A voltammetric sensor was developed based on a glassy carbon electrode with aluminophosphate zeolite finely dispersed on its surface, modified with a polyelectrolyte complex of chitosan with succinyl chitosan and betulinic acid, for the selective detection and determination of naproxen enantiomers. The electrochemical and analytical characteristics of the sensor were studied, and the effective electrode surface area (A = 9.8 ± 0.5 mm2) and charge transfer resistance (Ret = 649.9 ± 0.4 Ω) were calculated. In determining naproxen enantiomers, calibration characteristics are linear in the range from 2.5 × 10–5 to 1 × 10–3 M with limits of detection of 1.1 × 10–7 and 1.5 × 10–7 M and limits of quantification of 3.6 × 10–7 and 4.9 × 10–7 M for R- and S-naproxen, respectively. The sensor is more sensitive to R-naproxen (∆Ep = 60 mV, ipR/ipS = 1.40). The proposed sensor was used to recognize and determine naproxen enantiomers in human urine and plasma samples. Statistical evaluation of the results by the standard addition method showed that there was no systematic error.

A Voltammetric Sensor Based on Aluminophosphate Zeolite and a Composite of Betulinic Acid with a Chitosan Polyelectrolyte Complex for the Identification and Determination of Naproxen Enantiomers

A Voltammetric Sensor Based on Aluminophosphate Zeolite and a Composite of Betulinic Acid with a Chitosan Polyelectrolyte Complex for the Identification and Determination of Naproxen Enantiomers

Nanocomposite thin-film structures based on a polyelectrolyte complex of chitosan and chitosan succinamide with SWCNT

The article is devoted to the study of nanocomposite thin films based on a polyelectrolyte complex of chitosan and chitosan succinamide (PEC). Single-walled carbon nanotubes (SWCNT) were used as fillers. Using the methods of cyclic voltammetry and electrochemical impedance spectroscopy, it was found that nanocomposite films have a larger effective surface area and electron transfer rate compared to polyelectrolyte complex films, which allows them to be further used in the electroanalysis of substances of various nature. The study of the surface of the nanocomposite structure of PEC with SWCNT using SEM showed that there are formations in the form of filaments formed by carbon nanotubes on it. Studying the nature of morphology is extremely important when creating sensory devices. Sensory sensitivity of resistive thin-film nanocomposite structures to air humidity and ammonia vapors was found. Based on these nanocomposite materials, samples of resistive thin-film structures were prepared, the dependences of the flowing current on the relative humidity of the air and the concentration of ammonia vapors were measured.

Application of mathematical modelling to alginate chitosan polyelectrolyte complexes for the prediction of system behavior with Venlafaxine HCl as a model charged drug

PurposeThis work aimed to develop and analyze the performance of chitosan/alginate polyelectrolyte complex (PEC). Multiple regression and Lab fit curve fitting were applied to derive empirical models for the prediction of zeta potential of plain systems as a function of alginate chitosan ratio. Venlafaxine-HCl was loaded as a model charged drug and empirical models for prediction of its release as a function of time were also derived. MethodsCoacervation method was used for the preparation of green PECs. Preliminary studies were conducted to optimize the preparation method. Pre-adjustment of the pH of alginate and chitosan sols enabled the formation of PECs at alginate/chitosan ratios starting from 1:9 to 9:1. On mixing of alginate and chitosan sols, equal volume dilution method produced spherical particles, while direct mixing method gave fibrous particles. Twenty-seven PECs nanoparticle formulae were prepared using nine alginate/chitosan ratios and three levels of total polymer concentrations. ResultsStatistical analysis showed that Zeta potential of the nanoparticle was significantly dependent on alginate/chitosan ratio, while particle size was a function of total polymer concentration. Nine fiber formulae were prepared and evaluated for their appearance and zeta potential. Venlafaxine-HCl release followed anomalous transport mechanism. FT-IR and DSC studies confirmed complexation at the carboxylate and amine site at alginate and chitosan respectively. ConclusionChitosan/alginate PECs were successfully obtained without a cross-linker and empirical equations were obtained to help finding the best composition for loading charged drugs and to predict their release profiles.

Vapor-induced polyelectrolyte complexation of chitosan/pectin: A promising strategy for the preparation of hydrogels for controlled drug delivery

An innovative vapor-induced polyelectrolyte complexation process mediated by the acetic acid vapor is reported in this study as an alternative to preparing hydrogels of chitosan and pectin. Usually, this kind of hydrogel is prepared by the conventional solution mixture method, which results in materials with limited properties. Beyond demonstrating the efficiency of this process, a deep investigated throw light into the structure-properties relationships of these hydrogels, which could be useful to orientate their further application. The different characterization analyses demonstrated that the hydrogels obtained through the polyelectrolyte complexation of chitosan and pectin using this alternative method possess ordered regions within their structures. This configuration results from the packing of the polysaccharide chains due to the strong electrostatic interactions among the charged functional groups, being a direct result of the slow-rate complexation process driven by the vapor-induction. In terms of application, this structural characteristic of the hydrogels prepared by the vapor-induced method was pivotal to controlling and prolonging the release rate of curcumin, which was previously encapsulated into these hydrogels. Moreover, the experimental data for the release of CUR from these hydrogels was well-fitted by zero-order kinetics, differing from the hydrogels prepared through the conventional mixture of chitosan/pectin solutions. In summary, the molecular and microstructural understanding of the polyelectrolyte complexation of chitosan and pectin driven by this original vapor-mediated method raises as an alternative to prepare hydrogels with specific and tailored properties, which can be beneficial for drug delivery applications.

Self-assembled polyelectrolyte complexes of chitosan and fucoidan for sustained growth factor release from PRP enhance proliferation and collagen deposition in diabetic mice.

Diabetic wound management is a serious health care challenge due to higher rates of relapse, expensive treatment approaches, and poor healing outcomes. Among cell-based therapies, use of platelet-rich plasma (PRP) has been shown to be effective for diabetic wounds, but its poor shelf-life limits its clinical use. Here, we demonstrate a simple but effective polymer system to increase the shelf-life of PRP by developing a polyelectrolyte complex with dropwise addition of chitosan solution containing PRP by simple mixing at room temperature. Thus, prepared chitosan-fucoidan (CF) carrier complex encapsulated more than 95% of the loaded PRP. The resulting CF/PRP colloids were spherical in shape and ensured extended PRP release up to 72h at 37°C. Routine characterization (FT-IR, XRD, SEM) showed the material properties. The biological assays showed that CF complexes were biocompatible while CF/PRP enhanced the proliferation of fibroblasts and keratinocytes via higher Ki67expression and fibroblast migration. Further investigations using a diabetic mouse model demonstrated significantly higher wound contraction and histopathological observations showed increased fibroblast migration, and collagen and cytokeratin deposition in treatment groups. The results are suggestive of the efficacy of CF/PRP as a cost-effective topical formulation for the sustained delivery of growth factors in treating chronic diabetic wounds.

Preparation and characterization of chloridazon-loaded alginate/chitosan nanocapsules.

In addition to the detrimental environmental effects of herbicides, including the pollution of soil, atmosphere, groundwater aquifers and run-off water, the lack of caution and direct or indirect exposure to these products can cause short-term and long-term human health effects. However, nanotechnology, with its many applications, can be very helpful in improving agriculture and reducing the side effects of chemicals used in agriculture. Nano-encapsulation of chemicals used in agriculture is one of the strategies to improve precision agriculture. Nano-encapsulated herbicides are controlled membrane systems in which the active ingredient is coated with semi-permeable membranes, which may be organic or inorganic polymers. In our study, chloridazon herbicide was selected as the active ingredient for Nano-encapsulation. Like many other agricultural herbicides, the major problem with this herbicide is environmental pollution and its adverse health effects. The ionic gelation method was used to synthesize nanocapsules consisting of alginate and chitosan for chloridazon encapsulation. Alginate-chitosan nanoparticles were prepared in a two-step process involving the ionotropic pre-gelation of an alginate core and then the formation of a chitosan polyelectrolyte complex. The alginate-chitosan nanocapsules containing chloridazon were synthesized at a size of 253 nm with a polydispersity index (PDI) of 0.266 and a zeta potential of -1.43 mV. The loading capacity and entrapment efficiency of these nanocapsules were 14% and 57%, respectively. The study of chloridazon release from formulated alginate-chitosan nanocapsules was performed using dialysis tube testing and UV spectroscopy. The results of our study showed controlled release of chloridazon from loaded alginate-chitosan nanocapsules. In general, alginate-chitosan nanocapsules as a Nano-carrier, have the potential to become a commercial formulation for chloridazon encapsulation. On the other hand, controlled release and increasing the duration of action of chloridazon, along with reducing the required dose, is promising in reducing the adverse health and environmental effects caused by chloridazon and improving precision agriculture.

Dynamic behavior of tough polyelectrolyte complex hydrogels from chitosan and sodium hyaluronate

In this work, we investigated the dynamics of hydrogels from the polyelectrolyte complexation of sodium hyaluronate (HA) and chitosan under various temperature and salt concentration. Raising temperature and adding salt remarkably reduce the mechanical behavior of hydrogels. The stress relaxation of semi-flexible chain segments is accelerated at high temperature and salt concentration, which is controlled by thermally activated bond disassociation process. The flow activation energy determined from temperature-dependent dynamic light scattering decorrelation and rheological relaxation are in very good agreement. Our results suggest that the chain aggregations are physical crosslinked by surrounded semi-flexible chains, and their diffusion is highly hindered by the topological entanglements and ionic associations. The synergistic effect of aggregations diffusion and chain dynamics causes the slow macroscopic stress relaxation behavior of hydrogels before yield, independent of applied strain. Above yield, the amplitude of strain accelerates the stress relaxation, resulting in chain disentanglements and slipping.

Anti-Bacterial Activity of Chitosan-Alginate-Poly (Vinyl Alcohol) Hydrogel Containing Entrapped Peppermint Essential Oil

Polyelectrolyte complexes (PEC) of chitosan (CS) and sodium alginate (SA) containing various contents of peppermint essential oil (PEO), as a volatile bioactive agent, were prepared in order to investigate the effect of the oil on the anti-bacterial activity of the CS-SA hydrogels. The gelation of the PEC was performed in the presence of poly (vinyl alcohol) (PVA). Optical microscopic images exhibited uniform dispersion and entrapment of the oil within the PEC matrix. In-vitro evaluation tests of the hydrogels demonstrated the anti-bacterial activity of the PEO, revealing its potential for biomedical applications.

Fabrication of chitosan–alginate nanospheres for controlled release of cartap hydrochloride

Insecticide cartap hydrochloride (C) was fabricated as nanospheres by a two-step method of ionic gelification and polyelectrolyte complexation of alginate (ALG) and chitosan (CS) to undermine its adverse effects on environment. Nanospheres were characterized by field emission scanning electron microscope, Fourier transform infrared spectra and x-ray diffraction. The size of cartap hydrochloride entrapped chitosan alginate nanospheres (C-CS-ALG nps) was in range of 107.58–173.07 nm. Cartap hydrochloride nanospheres showed encapsulation efficiency of 76.19% and were stable for 30 d at ambient temperature. Release of cartap from nanospheres fitted best with first order linear kinetics followed by Hixson and Higuchi model suggesting super case II transport release. With the application of such control release nanoformulations, it is possible to reduce the frequency of field application of insecticide due to its slow release to the target organism, which is economical as well as environmentally safe.