Cationic Polysaccharide Research Articles

Legionella pneumophila Attachment to Biofilms of an Acidovorax Isolate from a Drinking Water-Consortium Requires the Lcl-Adhesin Protein.

Human infection by Legionella pneumophila (Lpn) only occurs via contaminated water from man-made sources, and eradication of these bacteria from man-made water systems is complicated by biofilm colonization. Using a continuously fed biofilm reactor model, we grew a biofilm consortium from potable water that was able to prolong recovery of Lpn CFU from biofilms. This effect was recreated using a subset of those species in a simplified consortium composed of eight bacterial isolates from the first biofilm reactor. In the reactor with the eight-species consortium, Lpn biofilm CFU was relatively stable over a 12-day trial. An isolate of Acidovorax from the consortium was, as a single species biofilm, able to promote Lpn surface attachment. Other isolates from the Pelomonas genus grew as equally robust biofilms alone, but did not promote surface attachment of Lpn. This attachment was disrupted by cationic polysaccharides and loss of the Lpn Lcl collagen-like adhesin protein. This work demonstrates that, while Lpn was fairly incompetent at attachment to surfaces to form a biofilm alone, pre-existing biofilms allowed attachment of Lpn as secondary colonizers. In addition, we demonstrate that initial attachment of Lpn to Acidovorax biofilms is likely via the Lcl-adhesin protein.

Hyperbranched cationic polysaccharide derivatives for efficient siRNA delivery and diabetic wound healing enhancement

Gene vectors are important for successful siRNA delivery. Four types of hyperbranched cationic polysaccharide derivatives (HCP) were synthesized by conjuncting 1,2-ethylenediamine (EDA) and diethylenetriamine (DETA) with glycogen or amylopectin respectively and named as G-EDA, G-DETA, A-EDA and A-DETA. The efficiency and safety of these HCPs to deliver siRNA were explored in vitro and in vivo. Our results showed that HCPs could form complexes with siRNA. All HCP/siRNA exhibited negligible cytotoxicity. Compared with A-EDA and A-DETA, G-EDA and G-DETA could carry much more siRNA into cells and then escape from endosomes. The delivery of MMP-9 siRNA (siMMP-9) by G-EDA and G-DETA significantly inhibited MMP-9 in HaCaT cells. Wound models in diabetic rats demonstrated that treatment of G-EDA/siMMP-9 could potently knock down MMP-9 of skin wound tissues and then enhanced wound healing. In summary, this study provided an effective and safe approach for siRNA delivery in vitro and in vivo.

Activity of Chitosan and Its Derivatives against Leishmania major and Leishmania mexicana In Vitro.

There is an urgent need for safe, efficacious, affordable, and field-adapted drugs for the treatment of cutaneous leishmaniasis, which newly affects around 1.5 million people worldwide annually. Chitosan, a biodegradable cationic polysaccharide, has previously been reported to have antimicrobial, antileishmanial, and immunostimulatory activities. We investigated the in vitro activity of chitosan and several of its derivatives and showed that the pH of the culture medium plays a critical role in antileishmanial activity of chitosan against both extracellular promastigotes and intracellular amastigotes of Leishmania major and Leishmania mexicana Chitosan and its derivatives were approximately 7 to 20 times more active at pH 6.5 than at pH 7.5, with high-molecular-weight chitosan being the most potent. High-molecular-weight chitosan stimulated the production of nitric oxide and reactive oxygen species by uninfected and Leishmania-infected macrophages in a time- and dose-dependent manner at pH 6.5. Despite the in vitro activation of bone marrow macrophages by chitosan to produce nitric oxide and reactive oxygen species, we showed that the antileishmanial activity of chitosan was not mediated by these metabolites. Finally, we showed that rhodamine-labeled chitosan is taken up by pinocytosis and accumulates in the parasitophorous vacuole of Leishmania-infected macrophages.

Fabrication and Characterization of Polysaccharide Composite Films from Polyion Complex Particles.

Biomaterials made of natural polysaccharides have attracted much attention due to the fact of their excellent properties, such as high biocompatibility and biodegradability, and their specific biological functions based on their chemical structures. This study demonstrates that polysaccharide composite films can be fabricated from polyion complexes (PICs) with their particles used as building components. Dispersion of PIC particles prepared by mixing, centrifugation, and re-dispersion of dilute solutions of cationic and anionic polysaccharides were cast, dried, and formed into films several micrometers thick. These films were homogenous and water insoluble. It was revealed that the component anionic polysaccharides affected the film’s properties such as the swelling behavior and mechanical characteristics. Adhesion of NIH3T3 cells (integrin: high, CD44: lack or weak) and A549 cells (integrin: high, CD44: high) to the composite films were examined. Both NIH3T3 and A549 cells adhered to heparin/chitosan (HEP/CHI) film because HEP has an affinity for integrin through fibronectin. However, A549 cells adhered to chondroitin sulfate (CS)/CHI and hyaluronic acid (HYA)/CHI films, whereas NIH3T3 cells did not, because both CS and HYA have affinity for CD44. These results indicated that the biological functions of anionic polysaccharides were maintained on the surface of the composite films. It was also possible to fabricate films composed of three kinds of polysaccharides: one cationic polysaccharide and two kinds of anionic polysaccharides. These results show that the properties of films composed of three kinds of polysaccharides may be controllable depending on the anionic polysaccharide composition rates.

Influence of anionic, neutral, and cationic polysaccharides on the in vitro digestibility of raw and gelatinized potato starch.

Polysaccharides have been expected to have a suppressive effect on starch digestibility by blending. The objective of this study was to investigate the effects of anionic (xanthan gum), neutral (guar gum), and cationic (chitosan) polysaccharides on the in vitro digestibility of raw and gelatinized starch using six potato cultivars differing in phosphorus content. By comparing the starch digestibility between potato cultivars, a significant difference was observed for the raw starches, and 'Benimaru', which is a potato cultivar containing a higher proportion of short-chain amylopectin and the lowest phosphorus content in starch, showed a distinctly faster rate of starch hydrolysis. The added polysaccharides decreased the extent of digestion of both raw and gelatinized starches. No significant correlation between phosphorus content and the extent of starch digestion was observed in mixed systems, whereas significant correlations were noted between the extent of starch digestion and Rapid Visco Analyser parameters. The extent of raw and gelatinized starch digestion negatively correlated with pasting temperature, initial viscosity before heating, and peak viscosity (P < 0.01). The added polysaccharides were observed to decrease the starch digestibility, and their suppressive effects were mainly dependent on the increase of viscosity rather than chemical interactions. A combination of potato cultivar and type of polysaccharide was proved to be important for nutritional value of potato starch. © 2020 Society of Chemical Industry.

Clickable modular polysaccharide nanoparticles for selective cell-targeting

A therapeutic nanocarrier capable of cell targeting has the potential to reduce off-target effects of otherwise effective drugs. Nanoparticle surface modification can be tailored for specific cells, however multistep surface modification can prove slow and difficult for a variety of cell types. Here, we designed drug carrying polysaccharide based nanoparticles with a layered structure for clickable surface modification. The center of nanoparticle was composed of cationic macromer (e.g., poly-l-lysine) and anionic polysaccharide (e.g., heparin). Furthermore, a ‘clickable’ polysaccharide was installed on the surface of the nanoparticles to permit a wide range of bioconjugation via norbornene-tetrazine click chemistry. The utilities of these layered nanoparticles were demonstrated via enhanced protein sequestration, selective cell targeting (via PEGylation or altering polysaccharide coating), as well as loading and release of chemotherapeutic. The drug-loaded nanocarriers proved cytotoxic to J774A.1 monocytes and MOLM-14 leukemia cells.

Naturally-occurring bacterial cellulose-hyperbranched cationic polysaccharide derivative/MMP-9 siRNA composite dressing for wound healing enhancement in diabetic rats

The anomalous high expression of matrix metalloproteinase 9 (MMP-9) is one important factor that impedes diabetic wound healing. Therefore, inhibition of MMP-9 expression in a diabetic wound could be a feasible method to promote wound healing. In this study, we studied the possibility of self-therapy using wound dressings that contain bacterial cellulose-hyperbranched cationic polysaccharide (BC-HCP) derivatives that encapsulate siRNA (BC-HCP/siMMP-9) and have controlled release properties. Herein, we used four HCPs (Gly-DMAPA, Gly-D4, Amyp-DMAPA, Amyp-D4) as gene carriers. Our results showed that all HCP derivatives were minimally toxic to cells in vitro, while the cationic properties of HCP could be used as a complexation agent for MMP-9 siRNA (siMMP-9). Upon exposure to bacterial cellulose (BC), the BC slowly released HCP/siMMP-9. The released siMMP-9 effectively reduced the gene expression and protein levels of MMP-9 in a human immortalized epithelial cell line (HaCAT) and in diabetic rat wounds. Inhibition of MMP-9 in the wounds of diabetic rats resulted in a significant enhancement of wound healing, suggesting that the BC-HCP/siMMP-9 composite dressing could be used as a safe and effective dressing to promote wound healing in diabetic rats. STATEMENT OF SIGNIFICANCE: In this work, we evaluated the possibility of using bacterial cellulose-hyperbranched cationic polysaccharide derivatives (BC-HCP) as a self-therapeutic wound dressing with siRNA encapsulated and controlled release properties. Our results showed that the BC-HCP/siMMP-9 composite dressing slowly released HCP/siMMP-9. The released siMMP-9 effectively reduced the gene expression and protein level of MMP-9 in human immortalized epithelial cell line and in the wound of diabetic rats. The BC-HCP/siMMP-9 composite dressing promoted diabetic wound healing by the unique nanostructure of BC and by releasing siMMP-9 for specific MMP-9 inhibition. Therefore, it could be used as a safe and effective dressing to promote wound healing in diabetic rats. This is the first evidence on the study of using BC as a dressing composite by encapsulating HCP/siRNA complexes for efficient RNAi gene silencing for better wound healing in diabetic rats.

Alginate beads impregnated with magnetic Chitosan@Zeolite nanocomposite for cationic methylene blue dye removal from aqueous solution

In this study, magnetic bionanocomposite of sodium alginate (an anionic polysaccharide), chitosan (a cationic polysaccharide), impregnated with natural zeolite, and cross-linked with glutaraldehyde and CaCl2 in order to improve the stability, are prepared and used to methylene blue removal from aqueous solution. The synthesized magnetic Zeolite/Chitosan/Alginate (MZ/CS/AL) bionanocomposite was analyzed and characterized by FeSEM, EDX, XRD, BET surface area analysis, VSM, TGA, and FTIR techniques. The efficiency of the MZ/CS/AL biosorbent was studied by measuring the uptake using the batch and continuous technique experiments. The effect of contact time, pH, initial concentration of dye, and amount of adsorbent on dye adsorption capacity, kinetics, isotherm, thermodynamics, regeneration, and swelling were investigated. The results showed that the adsorption of methylene blue follows the pseudo-second-order kinetic model and Freundlich isotherm model. The thermodynamic results showed that dye adsorption process with synthetic adsorbent is an exothermic spontaneous process.

Formation and characterisation of food protein–polysaccharide thermal complex particles: effects of pH, temperature and polysaccharide type

SummaryThe objective of this study was to prepare and characterise the thermal complex particles (TCPs) based on heating food grade protein–polysaccharide electrostatic complexes. The soybean protein isolate (SPI), cationic polysaccharide (chitosan, CS) and anionic polysaccharide (carboxymethyl cellulose, CMC) were used. Turbidity, particle size, ζ‐potential and morphology of TCPs were measured. The results showed that SPI‐CS and SPI‐CMC soluble complexes were obtained at specific pHs and kept at high electrostatic repulsive force. The particle size and polydispersity index of stable SPI‐CS (pH 4.55/80 °C) and SPI‐CMC (pH 6.15/95 °C) TCPs were 286.6 nm/0.282 and 171.5 nm/0.298, respectively. We inferred that the re‐assembly of SPI after thermal denaturation resulted in the formation of TCPs. The pH and ionic strength sensitivity tests indicated that the TCPs with different properties can be controlled by pH, temperature and polysaccharide type during heating. These TCPs could be used to encapsulate food functional components which were thermal insensitive.

Chitosan and Quercetin: Potential Hand in Hand Encountering Tumors in Oral Delivery System.

Chitosan is a cationic polysaccharide and multi-potential polymer with the ability to interact with other natural and synthetic polyanionic/polymeric compounds, with or without a cross-linking agent. It has been able to composite nano-microparticles with a variety of features. This compound has the ability to carry quercetin, as an anti-tumor subject, through the various epithelial systems and release in the sustained and controlled state to the target site. This paper reviews published studies on detailed physicochemical properties of chitosan and quercetin in the fight against the tumor. This also focused on how the chitosan polymer interacts with other polymeric and polyanion species in order to improve its efficiency to make a more suitable capsule or matrix for a variety of drugs, especially quercetin, in oral delivery systems.

Synthesis and Characterization of Carbapenem Based Nanohybrids as Antimicrobial Agents for Multidrug Resistant Bacteria

Carbapenem antibiotics resistance is a medical threat in antibacterial therapy as the pathogen resistant strains easily evolve a multi-drug resistance action to other incurable agents. The protective transport of current antibiotic molecules using nano-carriers initiates a huge approach in the antibacterial therapy, allowing the nanohybrids to defeat all these health threat pathogen agents. Chitosan is a linear cationic polysaccharide being often used in medical area as a biocompatible encapsulating agent in antibiotic delivery nanosystems. This work refers to encapsulation of imipenem into biodegradable chitosan nanoparticles in order to destroy antibiotic-resistant bacteria and limit the microbial adhesion and multiplication. Nanoparticles were prepared by ion gelation method using tripolyphosphate as cross linking agent. The obtained hybrid nanocapsules were then characterized and evaluated as a potential nano-device to beat antimicrobial resistance.

Chitosan enhances calcium carbonate precipitation and solidification mediated by bacteria.

Formation of the biominerals in living organisms is mainly associated with organic macromolecules. These organic materials play an important role in the nucleation, growth, and morphology controls of the biominerals. Current study mimics this concept of organic matrix- mediated biomineralization by using microbial induced carbonate precipitation (MICP) method in combination with the cationic polysaccharide chitosan. CaCO3 precipitation was performed by the hydrolysis of urea by the ureolytic bacteria Pararhodobacter sp. SO1 in the presence of CaCl2, with and without chitosan. The crystal polymorphism and morphology of oven-dried samples were analyzed by X-ray diffraction and scanning electron microscopy. The amount of precipitate obtained was higher in the presence of chitosan. The precipitate included both of the CaCO3 and the chitosan hydrogel. Rhombohedral crystals were dominant in the precipitate without chitosan and distorted crystal agglomerations were found with chitosan. Sand solidification experiments were conducted in the presence of chitosan under different experimental conditions. By adding chitosan, more strongly cemented sand specimens could be obtained than those from conventional method. All of these results confirm the positive effect of chitosan for the CaCO3 precipitation and sand solidification.

Formation of highly quaternized N,N,N-trimethylchitosan: a chemoselective methodology in aqueous media

Abstract N,N,N-Trimethylchitosan (TMC) represents a rare example of cationic polysaccharides and numerous studies have shown its potential in biological and biomedical applications. TMC with high degrees of quaternization (DQ) were synthesized from N-methylation of N,N-dimethylchitosan (DMC), which was obtained by reductive alkylation of high molecular weight chitosan in a simple step process and in good yields. The effects of base and solvents were evaluated on the quaternization reaction. The N-methylation of DMC was performed selectively by CH3I and carbonate in water where quaternization was achieved quantitatively with a low degree of O-methylation (17 %). Moreover, the greener procedure allows easy recovery and purification by conventional filtration as a carbonate salt, in which the anion can be exchanged by an acid-base reaction. Quantification of DQ involving 1H NMR integration of methyl peaks must be performed on protonated TMC. High field NMR spectra of TMC showed two specific chemical shifts for anomeric peaks (5.0 and 5.4 ppm) that can also be used for the determination of DQ. This latter method avoids the superimposition problems with other pyranosyl peaks.

Effect of Mesoporous Silica Nanoparticles on Glycerol-Plasticized Anionic and Cationic Polysaccharide Edible Films

This study describes the production of reinforced polysaccharide (PS)-based films, by adding mesoporous silica nanoparticles (MSNs), to either pectin (PEC) or chitosan (CH) film forming solutions, either containing glycerol (GLY) as a plasticizer, or not. Film characterization demonstrated that MSNs and GLY were able to significantly increase the plasticity of both PS-based biomaterials and that the interactions between PSs and nanoparticles were mainly due to hydrogen bonds. Moreover, MSN-containing films were less transparent, compared to controls prepared with either PEC or CH, in the absence of GLY, while all films containing MSNs, but obtained with the plasticizer, were as transparent as the films prepared with PEC or CH alone. MSN addition did not influence the thickness of the PEC-based films, but increased that of CH-based ones, prepared both in the absence and presence of GLY. MSN-containing PEC-based films possessed a more compact and homogeneous morphology, with respect to both control films, prepared, with or without GLY, and to the CH-based films, containing MSNs, the structure of which showed numerous agglomerations. Finally, moisture content and uptake were reduced, in all films prepared in the presence of MSNs. The suggested addition of MSNs might have given rise to novel biomaterials for food or pharmaceutical applications.

Effects of dietary chitosan supplementation on farmed fish; a review

AbstractChitosan is a cationic polysaccharide that is primarily derived from chitin, a natural polymer of N‐acetyl glucosamine mainly found in crustacean, insect exoskeletons and fungal cell walls, by exhaustive alkaline deacetylation to varying degrees. Chitosan has been found to have many favourable biological properties including biosafety, biodegradability and biocompatibility. These advantages make it a very promising material for diverse applications. For terrestrial animals, chitosan has been widely used as a feed additive because of its low side effects, enhancing the growth performance, improving immune functions, inhibition intestinal microbial pathogens and lowering cholesterol. Recently, it has been used as a feed additive in fish diets. Moreover, chitosan has gained an attention as an effective agent in aquaculture water treatment. A number of studies have been conducted on the effectiveness of the use of chitosan in aquaculture. Thus, the present review explored the current state of knowledge on the effects of dietary chitosan on farmed aquatic animals including antimicrobial, growth promoting, antioxidant activity and immunostimulation effects, with a particular emphasis on the optimal dose of chitosan. As well as, this review pointed out the possibility of using chitosan in aquaculture water treatment. According to the studies that were discussed in this review, chitosan is considered as a promising material with a massive potential of applications in aquaculture.

Creation of Straight-Chain Cationic Polysaccharide-Based Bile Salt Sequestrants Made from Euglenoid β-1,3-Glucan as Potential Antidiabetic Agents.

Straight-chain polysaccharides have a greater potential of selectively adsorbing hydrophobic bile salts than resin-based bile salt sequesters because of ionic and hydrophobic interactions; hence, they may possess antidiabetic activity. The feasibility of using cationic polysaccharides made from euglenoid β-1,3-glucan (referred to as paramylon) as potential antidiabetic agents was examined by using in vitro and animal experiments. Cationic straight-chain polysaccharides were synthesized from euglenoid polysaccharide and glycidyltrimethylammonium chloride. The effects of administration of the synthetic polysaccharide on metabolic syndrome-related indicators were examined in high-fat diet-induced obesity mice. The degree of adsorption of bile salts by the polysaccharides was evaluated using spectroscopic analysis. Administration of the cationic paramylon derivatives significantly reduced body and mesenteric fat weight in high-fat diet-induced obesity mice. A noteworthy effect was that glucagon-like peptide-1 (GLP-1) secretion was approximately three times higher in diet-induced obesity mice receiving cationic paramylon derivatives than in those receiving cellulose as a control. Our results indicate that these cationic paramylon derivatives are potential GLP-1 secretagogues suitable for further study.

PH Variation as a Simple and Selective Pathway for Obtaining Nanoparticle or Nanocapsule Polysaccharides.

The fabrication of polysaccharides to be nanoparticles or nanocapsules is quite specific due to various parameters and factors. The present work demonstrates a simple pathway to selectively prepare the ionic polysaccharide flakes to be nanoparticles or nanocapsules. The systematic studies on the model cases of cationic polysaccharide (i.e., chitosan) and anionic polysaccharide (i.e., alginate) confirm that p Ka is the key point to tune the polysaccharides to be nanoparticles or nanocapsules. When the ionic polysaccharides were in an oil/water emulsion system, the pH close to p Ka leads to the densely packed polysaccharide chains under the hydrogen bond networks, and as a result the cross-link occurs all through the chains to be nanoparticles. On the other hand, when pH was adjusted to the lower or higher than p Ka depending on the types of ionic polysaccharide, the polysaccharide chains are under charge-charge repulsive force, resulting in the alignment of polysaccharide chains to be hollow nanospheres, and at that time the cross-link initiates the formation of nanocapsules. The present work, for the first time, clarifies that pH variation is the key to selectively prepare nanoparticles or nanocapsules, and this is important for delivery systems, coatings, sensors, and so forth.

Biosynthesis and Potential Applications of Silver and Gold Nanoparticles and Their Chitosan-Based Nanocomposites in Nanomedicine

Biosynthesized or biogenic metallic nanoparticles, particularly silver and gold nanoparticles (AgNPs and AuNPs, respectively), have been increasingly used because of their advantages, including high stability and loading capacity; moreover, these nanoparticles are synthesized using a green and cost-effective method. Previous studies have investigated reducing and/or stabilizing agents from various biological sources, including plants, microorganisms, and marine-derived products, using either a one-pot or a multistep process at different conditions. In addition, extensive studies have been performed to determine the biological or pharmacological effects of these nanoparticles, such as antimicrobial, antitumor, anti-inflammatory, and antioxidant effects. In the recent years, chitosan, a natural cationic polysaccharide, has been increasingly investigated as a reducing and/or stabilizing agent in the synthesis of biogenic metallic nanoparticles with potential applications in nanomedicine. Here, we have reviewed the mechanism of biosynthesis and potential applications of AgNPs and AuNPs and their chitosan-mediated nanocomposites in nanomedicine.

Investigation of charge ratio variation in mRNA – DEAE-dextran polyplex delivery systems

mRNA pharmaceuticals represent a new class of therapeutics, with applications, in cancer vaccination, tumour therapy and protein substitution. Formulations are required to deliver messenger RNA (mRNA) to the target sites where induction of genetic transfection following receptor mediated cell uptake & translation is required.In the current study, the cationic polysaccharide diethylaminoethylen (DEAE) – Dextran was selected as a model system carrier for the investigation of polyplex nanoparticle formation together with mRNA as a function of the molar ratio of the components. The structure of the mRNA/Dextran colloids was investigated as a function of the polymer-to-mRNA ratio and correlated with the biological activity determined by cellular transfection with luciferase coding mRNA. Dynamic light scattering (DLS), small angle x-ray scattering (SAXS), and small angle neutron scattering (SANS) with deuterium contrast variation were used to achieve structural insight into the systems. Similarly to previously investigated lipid based systems, colloidally stable particles with confined size were obtained with either excess of positive or negative charge. Highest activity was obtained with positive charge excess. From the scattering experiments information on the internal organization inside the polymer/mRNA systems was derived. Indication for the presence of structural elements in the length scale of ten to 20 nm were found in the excess of dextran, which could be due to either excess or particulate polymer. Information on the molecular organization of the mRNA nanoparticle products may provide a valuable basis for defining critical quality attributes of drug products for pharmaceutical application.

Cationic polysaccharide spermine-pullulan drives tumor associated macrophage towards M1 phenotype to inhibit tumor progression

Macrophages are predominant immune cells in the tumor microenvironment where they display an immunosuppressive M2 phenotype to support tumor growth. Reprogramming M2-like tumor-associated macrophages (TAMs) to antitumor M1 phenotype represents as a promising strategy in cancer immunotherapy. In this work we reported that one cationic polysaccharide spermine modified pullulan (PS) could act as an effective immunological stimulator to modulating either naïve (M0) or M2 macrophages towards M1 phenotype. We showed that PS upregulated the expression of TLR1/3/4 and promoted the phosphorylation of Akt, Erk, JNK, following the activation of NF-κB, which led to the polarization towards M1. In a murine breast cancer model of tumor cell 4T1 inoculation, subcutaneous injection of PS induced effective antitumor effect through reprogramming M2 macrophages in the tumor microenvironment to M1, increased CD4+ and CD8+ T cells, and decreased the expression of CD31 in the tumor mass, which together inhibited the tumor progression and the metastasis in lung and liver, leading to the prolong of the mice survival. In conclusion, PS could effectively stimulate the immunological function of macrophages. Therefore, PS may provide a novel immunological stimulator to cancer immune therapies.