Different Molecular Weights Of Chitosan Research Articles

Influence of chitosanon on the ability of LPS to interact with cells of the immune system

Complexes of lipopolysaccharide (LPS) from the bacterium Escherichia coli and chitosan (CN) with a molecular weight of 5 kDa were obtained and their supramolecular organization was studied. Using atomic force microscopy, it was shown that during the formation of complexes there is a transition from the micellar structure of the original LPS to linear network structures uniformly distributed over the surface of mica. The stability of LPS-CN complexes of various stoichiometries in biological media in the presence of serum proteins was investigated. It was shown that complexes with an LPS:CN ratio of 1:1 in the presence of serum proteins lost their surface charge and tended to aggregate; while complexes with maximum saturation of CN (1:5) did not aggregate under these conditions and maintained their surface charge. The effect of CNs of different molecular weights on the ability of LPS to interact with neutrophils in human whole blood was studied. It was observed that LPS-CN complexes were capable of binding to neutrophils and entering the cell, and this ability was enhanced in the presence of serum proteins. Chitosan exhibited the ability to suppress the synthesis of the proinflammatory cytokine TNF-α, induced by LPS, not only as part of the complex but also when cells were pretreated with a polycation.

Preparation and Characterization of Hydrogels Fabricated From Chitosan and Poly(vinyl alcohol) for Tissue Engineering Applications.

In this study, we report on the preparation, characterization, and cytocompatibility of hydrogels for biomedical applications made from two different molecular weights of chitosan (CS) blended with poly(vinyl alcohol) (PVA) and chemically cross-linked with tetraethyl orthosilicate (TEOS) followed by freeze-drying. A series of CS-PVA hydrogels were synthesized with different amounts of chitosan (1%, 2%, and 3% by weight). The structure of these CS-PVA hydrogels was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The hydrogel samples were also characterized for tensile strength, contact angle, swelling behavior, and degradation at physiological body temperature. Their physicochemical properties, biocompatibility, and cell viability when cultured with human dermal fibroblasts were assessed using alamarBlue and live/dead assays and compared to optimize their functionality. SEM analysis showed that the concentration and molecular weight of the chitosan component affected the pore size. Furthermore, the contact angle decreased with increasing chitosan content, indicating that chitosan increased its hydrophilic properties. The in vitro degradation study revealed a nonlinear time-dependent relationship between chitosan concentration or molecular weight, and the rate of degradation was affected by the pore size of the hydrogel. All of the CS-PVA hydrogels exhibited good cell proliferation, particularly with the high molecular weight chitosan samples.

BINARY CHITOSAN/QUATERNIZED CHITOSAN VIA ELECTROSPINNING. MORPHOLOGY AND ANTIMICROBIAL ACTIVITY

The paper reports about binary chitosan/quaternized chitosan nanofibers obtained by direct electrospinning of their solution, without using co-spinning polymers. Both quaternary salts, N,N,N-trimethyl chitosan chloride and N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride, were used in the electrospinning process and provided nanofibers with a mean diameter lower than 100 nm. A morphological evaluation of the nanofibers prepared with quaternized chitosan and chitosan of different molecular weights indicated that chitosan of lower molecular weight yielded fibers of higher diameter, due to the necessity to increase the concentration of the electrospinning solution in order to reach chain entanglement. Polarized light microscopy suggested that the fibers were semicrystalline in nature, in line with the ability of the macromolecular chains to align in an electrical field. Furthermore, the investigation of the antimicrobial and antifungal activities against relevant gram-positive and gram-negative bacteria, as well as yeast strains, revealed the strong effects of the nanofibers, improved by the presence of quaternary chitosan and the lower diameter of the fibers.

THE EFFECTS OF APPLYING CHITOSAN OF DIFFERENT MOLECULAR WEIGHTS ON THE QUALITY OF KAMCHATKA BERRIES (LONICERA CAERULEA L.): PART 2

We evaluated the effects of chitosan of different molecular weights on the quality of Kamchatka berries after harvest and storage. Chitosan with lower molecular weights (from 3 to 21 kDa) positively influenced the soluble solid content after harvest. However, chitosan had no significant effect on titratable acidity after harvest. Regardless of the chitosan molecular weight, the berries contained from 7.4% to 30% more total polyphenols compared with the control (162 mg per 100 g) after harvest. After storage, the total phenolic content decreased slightly and depended on the storage conditions. The L-ascorbic acid content was the highest after harvest and storage after treatment with the highest molecular weight of chitosan (950k kDa). Chitosan 50 kDa positively influenced the firmness and puncture resistance of the berries after harvest (146% of control) and storage (135% of control).

Integrating omics and network pharmacology reveals the anti-constipation role of chitosan with different molecular weights in constipated mice

This study aimed to reveal the constipation-relieving role of chitosan (COS) with different molecular weights (1 kDa, 3 kDa and 244 kDa). Compared with COS3K (3 kDa) and COS240K (244 kDa), COS1K (1 kDa) more significantly accelerated gastrointestinal transit and defecation frequency. These differential effects were reflected in the regulation of specific gut microbiota (Desulfovibrio, Bacteroides, Parabacteroides and Anaerovorax) and short-chain fatty acids (propionic acid, butyric acid and valeric acid). RNA-sequencing found that the differential expressed genes (DEGs) caused by different molecular weights of COS were mainly enriched in intestinal immune-related pathways, especially cell adhesion molecules. Furthermore, network pharmacology revealed two candidate genes (Clu and Igf2), which can be regarded as the key molecules for the differential anti-constipation effects of COS with different molecular weights. These results were further verified by qPCR. In conclusion, our results provide a novel research strategy to help understand the differences in the anti-constipation effects of chitosan with different molecular weights.

Structure and Properties of Thermomechanically Processed Chitosan-Based Biomimetic Composite Materials: Effect of Chitosan Molecular Weight

While natural biopolymers are promising sustainable resources to develop “green” materials, their unique properties make it challenging to process them as synthetic polymers, limiting their applications. This is mainly due to the intramolecular and intermolecular hydrogen bonds formed by the large number of −OH and other polar groups in natural biopolymers. Thermomechanical processing allows the breakage of the intramolecular and intermolecular hydrogen bonds and thus increases chain mobility. In this work, biomimetic materials based on chitosan and silk peptides were prepared by thermomechanical processing. The effect of different molecular weights of chitosan on the structure and properties of the composites was investigated. A combination of excellent strength (σt = 29.8 MPa) and toughness (εb = 100.5%) was obtained with a certain molecular weight of chitosan, and the toughness (εb = 143.4%) could be further enhanced by rehydration after drying. Consequently, this research demonstrated that the molecular weight of chitosan significantly influences the structure and properties of the composites. The results of the study provide a reference for the processing of natural polymeric materials by hot-melt methods.

THE INFLUENCE OF CHITOSANES ON THE DYNAMICS OF THE CONTENT OF PHENOLIC COMPOUNDS IN TOMATO LEAVES

The aim of this work was to study the influence of chitosans of different molecular weight on the dynamics of the content of phenolic compounds in tomato plants of the 'Zagadka' variety. In the experiment, tomato plants treated with chitosan with a molecular weight of 50-190 kDa and 310-375 kDa were studied. Using the method of high-performance thin-layer chromatography (HPTLC), biochemical profiling of the extracts of the studied plants was performed. Differences in the primary reactions of plants to chitosans of different molecular weights were revealed. Low molecular chitosan caused a significant increase in the content of phenols and, accordingly, increased the antioxidant potential of leaf tissues. The increase in the content of phenols in response to the action of low-molecular-weight chitosan occurs due to the activation of phenylpropanoid synthesis and an increase in the total antioxidant potential, which indicates the mobilization of the plant organism against a potential pathogen. Thus, an hour after the treatment of plants with a solution of low molecular weight chitosan, the content of rutin in the leaves was 3.36 mg/g, and after 18 hours - 5.56 mg/g. The content of chlorogenic and caffeic acids in the leaves increased in 12 hours. In 18 hours, the content of chlorogenic acid was 1.64 mg/g, and caffeic acid was 0.18 mg/g. This may be due to the gradual decomposition of chlorogenic acid into its constituent components under the influence of low molecular weight chitosan, which is accompanied by the release of caffeic acid. A positive correlation was established between the pool of chlorogenic and caffeic acid (r = 0.995; p < 0.06). Therefore, depending on the molecular weight, chitosan causes significant changes in the synthesis of phenylpropanoids and biochemical transformation of complex and simple esters of hydroxycinnamic acids in tomato plants. The high-molecular chitosan solution caused a decrease in the number of compounds with high antioxidant potential in tomato leaves, which indicates the activation of another plant defense system. The content of rutin in leaves treated with high-molecular-weight chitosan after 18 hours was 1.32 mg/g, which is four times less compared to the treatment of plants with low-molecular-weight chitosan. At the same time, in response to treatment with high molecular weight chitosan, the content of caffeic acid in the leaves increased significantly. The decrease in the content of phenols is associated with the isolation of tissues from a potential threat, which is aimed at its neutralization. The result of such a reaction is the oxidation of phenolic compounds, additional lignification and suberinization of cell walls. The activation of various induced immunity reactions in the plant organism already in the first hours after eating low-molecular or high-molecular chitosan indicates the existence of a system of differential recognition of complex bipolymers by plants.

Assessment of the Antibiofilm Performance of Chitosan-Based Surfaces in Marine Environments

Marine biofouling is a natural process often associated with biofilm formation on submerged surfaces, creating a massive economic and ecological burden. Although several antifouling paints have been used to prevent biofouling, growing ecological concerns emphasize the need to develop new and environmentally friendly antifouling approaches such as bio-based coatings. Chitosan (CS) is a natural polymer that has been widely used due to its outstanding biological properties, including non-toxicity and antimicrobial activity. This work aims to produce and characterize poly (lactic acid) (PLA)-CS surfaces with CS of different molecular weight (Mw) at different concentrations for application in marine paints. Loligo opalescens pens, a waste from the fishery industry, were used as a CS source. The antimicrobial activity of the CS and CS-functionalized surfaces was assessed against Cobetia marina, a model proteobacterium for marine biofouling. Results demonstrate that CS targets the bacterial cell membrane, and PLA-CS surfaces were able to reduce the number of culturable cells up to 68% compared to control, with this activity dependent on CS Mw. The antifouling performance was corroborated by Optical Coherence Tomography since PLA-CS surfaces reduced the biofilm thickness by up to 36%, as well as the percentage and size of biofilm empty spaces. Overall, CS coatings showed to be a promising approach to reducing biofouling in marine environments mimicked in this work, contributing to the valorization of fishing waste and encouraging further research on this topic.

EFFECT OF CHITOSAN-BASED SPRAYING ON THE QUALITY OF HIGHBUSH BLUEBERRIES (SUNRISE CULTIVAR)

The consumption of highbush blueberries has been growing rapidly in recent years due to their taste and health-promoting qualities. Various solutions have been sought to obtain the highest quality fruit after harvest. In the era of eco-friendly products, it is important that the methods used are natural and ecological. For this purpose, chitosan (CH) was sprayed five times on highbush blueberry bushes before harvesting. Different molecular weights of CH (5, 12, 21, 50, 125, and 500 kDa) were used in this study. The physical and biochemical characteristics of the fruit were investigated. The antioxidant activity, microbial contaminants, and mycotoxins in fruit were also analysed. Application of CH affected the quality of highbush blueberries after harvest. The molecular weight of CH had a significant effect on the studied traits. The application of high-molecular-weight CH improved physical characteristics such as the average weight of 100 blueberries, firmness, and puncture. Furthermore, the blueberries had a more intense blue colour; were characterised by a higher content of l-ascorbic acid and polyphenols, especially anthocyanins; and did not contain mycotoxins. Spraying with CH can be recommended in the organic cultivation of highbush blueberries to obtain robust fruit with health-promoting qualities.

Ecofriendly Removal of Aluminum and Cadmium Sulfate Pollution by Adsorption on Hexanoyl-Modified Chitosan

The purity and safety of water as a finite resource is highly important in order to meet current and future human needs. To address this issue, the usage of environmentally friendly and biodegradable adsorbers and flocculants is essential. Chitosan, as a biopolymer, features tremendous properties as an adsorber and flocculant for water treatment. For the application of chitosan as an adsorber under acidic aqueous conditions, such as acid mine drainage, chitosan has been modified with hydrophobic hexanoyl chloride (H-chitosan) to reduce the solubility at a lower pH. In order to investigate the influence of the substitution of the hexanoyl chloride on the adsorption properties of chitosan, two chitosans of different molecular weights and of three different functionalization degrees were analyzed for the adsorption of CdSO4(aq) and Al2(SO4)3(aq). Among biobased adsorbents, H-chitosan derived from the shorter Chitosan exhibited extraordinarily high maximum adsorption capacities of 1.74 mmol/g and 2.06 mmol/g for Cd2+ and sulfate, and 1.76 mmol/g and 2.60 mmol/g for Al3+ and sulfate, respectively.

Effect of Different Molecular Weights of Chitosan on Formulation and Evaluation of Allopurinol-Loaded Nanoparticles for Kidney Targeting and in Management of Hyperuricemic Nephrolithiasis.

Present research study was conducted to formulate kidney-targeted allopurinol (AO)-loaded chitosan nanoparticles (ANPs) for management of hyperuricemic related nephrolithiasis. Different molecular weights of chitosan were used for fabricating ANP formulation by adopting modified ionotropic gelation method. The prepared batches were than evaluated for particle size analysis, entrapment efficiency, transmission electron microscopy, X-ray diffraction, Differential Scanning Calorimetry, in vitro release and in vivo animal study. The in vivo study depicted that post 2 h of administration of different formulations and pure drug; ANPs prepared from low molecular weight chitosan showed maximum concentration of AO in kidney signifying successful kidney targeting of drug (25.92 fold) whereas no or very less amount of AO was seen in other animal groups. Effectiveness (p < 0.01) of formulation in management of hyperuricemia-associated nephrolithiasis was also evaluated via estimation of urine pH and serum and urine uric acid levels of mice. Further histological study was also performed on kidney samples which again affirmed these results. Present investigation demonstrated that ANPs prepared from low MW chitosan depicted maximum kidney-targeting ability that might be due to its specific uptake by the kidneys as well as its higher solubility than other two polymers, which results in enhanced release rate from the formulation and also offers an efficient strategy for the management of hyperuricemic nephrolithiasis.

One-step preparation of hydrogel based on different molecular weights of chitosan with citric acid.

Chitosan-based hydrogels have been prepared previously by a two-step protocol in which chitosan was first dissolved in dilute acetic acid and then crosslinked by glutaraldehyde or genipin. This was a time-consuming method, which had the disadvantages of high costs and biological safety problems. Scanning electron microscopy (SEM) results verified the successful preparation of hydrogels based on high, medium, and low molecular-weight chitosan (HCS, MCS, and LCS), respectively. The hydrogels prepared with HCS, MCS, and LCS were formed through the accumulation of different-sized crystals. The framework density of the hydrogel was enhanced by an increase in the chitosan molecular weight and exhibited a crack pore pattern composed of flake particles. Medium molecular-weight chitosan-based hydrogel exhibited the highest specific surface area and total pore volume, with values of 3.81 m2 g-1 and 0.0109 cm3 g-1 , respectively. The water absorption rate of the chitosan based hydrogels was influenced by its molecular weights at the sequence of LCS > HCS > MCS, while the maximum compression stress was affected at the sequence of HCS > MCS > LCS. The network structure was enhanced with an increase in the chitosan molecular weight and reached maximum stress levels of 4.50, 1.50 and 0.75 MPa for HCS-, MCS-, and LCS-based hydrogels, respectively. Citric acid was shown to be an effective dissolving and crosslinking agent in the preparation of MCS- and HCS-based hydrogels. The physiochemical properties of the hydrogels were enhanced as the molecular weight of the chitosan increased. © 2021 Society of Chemical Industry.

Adsorbent composites of montmorillonite and chitosan of different molecular weight, obtained by gamma irradiation

This work focuses on the structure and dye adsorption properties of different composition montmorillonite:chitosan (Mt:C) compounds for the remediation of water, using C of different molecular weights, easily obtained by gamma irradiation of C without further need of reagents. Chemical structure was characterized by FTIR, and differences in specific area and morphology were analyzed through BET and SEM. The lower molecular weight C eases the preparation of the compound and provides a higher specific area. Different intercalated - exfoliated behaviors were also observed through XRD, depending on the compositions and the molecular weight of the C samples. Cationic and anionic dyes were chosen as analogic model pollutants to carry out the adsorption experiments, followed through UV-Vis, and were found to fit with a pseudo-second order kinetic model. Adsorptions were also explored under different pH and dye concentrations. Results turned out to be promissory for the anionic dye, with a synergetic effect for the compounds with double proportion of Mt over C.

O-ATRP synthesized poly(β-pinene) blended with chitosan for antimicrobial and antioxidant bio-based films production

Antioxidant and antimicrobial activities are important characteristics of active film packaging designed to extend food preservation. In this study, functional bio-based films were produced using different concentrations of antioxidant poly(β-pinene) bio-oligomer synthesized via organocatalyzed atom transfer radical polymerization (O-ATRP) and blended with chitosan of different molecular weights. The structural, mechanical, thermal, solubility, antioxidant, and antimicrobial properties of the films were investigated. The poly(β-pinene)-chitosan blends presented significant pores and irregularities with the increase of poly(β-pinene) concentration over 30%. Chitosan molecular weight did not show any important influence in the physical properties of the blends. Poly(β-pinene) load decreased the materials' tensile strength and melting temperature, exhibiting a plasticizing effect on chitosan chains. The antioxidant and antimicrobial activities of the films were improved by poly(β-pinene) incorporation and mainly depended on its concentration. Therefore, the incorporation of poly(β-pinene) in chitosan films can be an alternative for active packaging production.

Chitosan/PVA Based Membranes Processed by Gamma Radiation as Scaffolding Materials for Skin Regeneration.

Some of the current strategies for the development of scaffolding materials capable of inducing tissue regeneration have been based on the use of polymeric biomaterials. Chitosan, in particular, due to its recognized biological activity has been used in a number of biomedical applications. Aiming the development of chitosan-based membranes with improved cell adhesion and growth properties to be used as skin scaffolds allowing functional tissue replacement, different formulations with chitosan of different molecular weight, poly (vinyl alcohol) and gelatin, were evaluated. To meet the goal of getting ready-to-use scaffolds assuring membranes’ required properties and sterilization, preparation methodology included a lyophilization procedure followed by a final gamma irradiation step. Two radiation dose values were tested. Samples were characterized by TGA, FTIR, and SEM techniques. Their hydrophilic properties, in vitro stability, and biocompatibility were also evaluated. Results show that all membranes present a sponge-type inner structure. Chitosan of low molecular weight and the introduction of gelatin are more favorable to cellular growth leading to an improvement on cells’ morphology and cytoskeletal organization, giving a good perspective to the use of these membranes as potential skin scaffolds.

Sub-100-micron calcium-alginate microspheres: Preparation by nitrogen flow focusing, dependence of spherical shape on gas streams and a drug carrier using acetaminophen as a model drug

We developed a miniature gas-liquid coaxial flow device using glass capillaries, aiming to produce sub-100-μm Ca-alginate microspheres. Depending on collecting distance and the flow rates of nitrogen gas and alginate solution, however, Ca-alginate microparticles of different shapes were obtained. Spherical, monodisperse microparticles (microspheres) could only be obtained at certain gas flow rates and within a corresponding range of collecting distance. The result suggests that, for particles of this size, the gas flow rate and collecting distance are crucial for the formation of the spherical shape. We evaluated, as an example of its applications, the microsphere as a drug carrier using acetaminophen as a model drug. Large (~150 μm) and small (~70 μm) drug-loaded microspheres were prepared using two respective devices. Specifically, the drug-loaded microspheres were complexed with chitosan of different molecular weights. The dependence of in vitro drug release on the microsphere size and the chitosan molecular weight was examined. Chemical compounds studied in this articleAlginic acid sodium salt (PubChem CID: 5102882); Chitosan (PubChem CID: 71853); Calcium chloride (PubChem CID: 5284359); Sodium chloride (PubChem CID: 5234); Acetaminophen (PubChem CID: 1983); Polydimethylsiloxane (PubChem CID: 24771); n-Octadecyltrimethoxysilane (PubChem CID: 76486).

Antifungal effect of chitosan of different molecular weight against Colletotrichum alatae under in vitro conditions

Antifungal effect of chitosan of different molecular weight against Colletotrichum alatae under in vitro conditions

Evaluation of Chitosan Nanomaterials in the Treatment of Helicobacter pylori Mediated Gastric Diseases

We assessed the effect of chitosan on Helicobacter pylori (HPY) in vitro to provide an experimental basis for the clinical application of chitosan in the treatment of gastric diseases. Here, the method of hole drilling was used to detect the bacteriostatic effect of different concentrations and pH values of chitosan on the standard bacterial strain Sydney strain I (SSI) and two strains of HPY isolated from patients. The bacteriostatic test was used to explore the effect of different molecular weights of chitosan and metal ions on the antibacterial effect of chitosan. The effect of chitosan showed no significant difference among three HPY strains (p < 0.05); moreover, in the range of pH 5.5-8.5, the antibacterial effect of chitosan increased with decrease in pH value (p < 0.01). A significant difference in the antibacterial effect of chitosan was observed at different concentrations (p < 0.01), reaching a peak at 40 g/mL. The molecular weight of chitosan was within 400 kb. With increasing molecular weight, the antibacterial activity of chitosan increased initially and then decreased. The molecular weight of 0.200 kb demonstrated the strongest anti-HPY effect, with the antibacterial effect observed for up to 134 h. Metal ions such as NaCl and MgCl₂ affected the anti-HPY effect of chitosan; with increasing concentration, the antibacterial percentage decreased.

Antioxidant and Moisturizing Properties of Carboxymethyl Chitosan with Different Molecular Weights.

This research aimed to synthesize carboxymethyl chitosan (CMCH) from different molecular weights of chitosan including low MW (L, 50–190 kDa), medium MW (M, 210–300 kDa) and high MW (H, 310–375 kDa) on the antioxidant and moisturizing properties. The L-CMCH, M-CMCH and H-CMCH improved the water solubility by about 96%, 90% and 89%, respectively when compared to native chitosan. Higher MW resulted in more viscous of CMCH. For antioxidant properties, IC50 values of DPPH and ABTS radical scavenging activity for L-CMCH were 1.70 and 1.37 mg/mL, respectively. The L-CMCH had higher antioxidant properties by DPPH and ABTS radical scavenging assay and FRAP. The moisturizing properties on pig skin using a Corneometer® showed that 0.5% H-CMCH significantly presented (p ≤ 0.05) greater moisturizing effect than that of untreated-skin, distilled water, propylene glycol and pure chitosan from three molecular weights.

Characterization of insect chitosan films from Tenebrio molitor and Brachystola magna and its comparison with commercial chitosan of different molecular weights

Insects are considered as alternative sources of chitosan; however, studies about the functional film-forming properties of insect chitosan are scarce. Insect chitosan films were made from Tenebrio molitor and Brachystola magna and were compared with commercial chitosan of different molecular weights (Mw). Mechanical properties (tensile strength, TS; elastic modulus, EM; elongation at break, %E), water vapor permeability (WVP) and physicochemical properties were characterized. The film properties of both commercial and insect chitosan were affected by Mw. Commercial chitosan films showed that at lower Mw, the TS (from 59 to 48 MPa) and EM (from 1471 to 1286 MPa) decreased; whereas WVP (from 2.9 × 10−11 to 3.4 × 10−11 g m−1s−1Pa−1), % E (from 38 to 41%) and solubility (from 30 to 33%) increased. Chitosan insect films showed lower TS and EM, and higher WPV, %E and solubility than commercial films. SEM revealed that chitosan insect films had lower porosity than commercial films. FTIR and X-ray diffraction showed not difference between insect and commercial chitosan films. These results showed that T. molitor and B. magna chitosan films could be used as a packaging material in several food products.