Chitosan Biguanidine Hydrochloride Research Articles

Chitosan Biguanidine/PVP Antibacterial Coatings for Perishable Fruits

World hunger is on the rise, yet one-third of food is wasted. It is necessary to develop an effective food preservation method to reduce food waste. This article reports a composite film based on chitosan biguanidine hydrochloride(CBg) and poly (N-vinyl-2-pyrrolidone)(PVP) that can be used as a conformal coating for fresh produce. Due to the strong positive charge of CBg, the film has excellent antibacterial properties. Owing to the hydrogen bonds between CBg and PVP, the film has good flexibility and mechanical properties. In addition, the coating is washable, transparent, and can reduce the evaporation of water. The above characteristics mean the film has broad application prospects in the field of food preservation.

Synergistic effect of Chitosan biguanidine hydrochloride salt as a green inhibitor for stainless steel alloy corrosion in a 0.5 M H2SO4 solution

The inhibition efficiency (IE) of the hydrochloride salt of chitosan biguanidine (CBG-HCl, a green organic compound) on stainless steel alloy (SS) corrosion in 0.5 M H2SO4 solution was documented in this work. Data reported for electrochemical impedance spectroscopy (EIS) and potentiodynamic analysis confirmed increasing of the corrosion resistance of stainless steel in 0.5 M H2SO4 solution in the presence of CBG-HCl with a synergistic effect of KI. Potentiodynamic experiments also indicate that the blend of CBG-HCl-KI works as a mixed-type inhibitor for stainless steel alloy corrosion. The best information gathered agreed with the Langmuir isotherm model. The corresponding normal Gibbs inhibitor adsorption free energy implied that the processes are random and involved two forms of interactions, chemisorption and physisorption. The highest inhibition efficiency (88 %) in this work was reported for 400 ppm of CBG-HCl blended with 800 ppm KI. In fact, with a long immersion time, the efficiency of CBG-HCl inhibition remains effectively high, demonstrating its good stability in the 0.5 M H2SO4 medium.

Optimized carboxymethyl cellulose and guanidinylated chitosan enriched with titanium oxide nanoparticles of improved UV-barrier properties for the active packaging of green bell pepper

Edible films based on chitosan biguanidine hydrochloride and CMC were optimized for the minimum water vapor permeability (WVP) using the 3-level factorial design. Titanium oxide nanoparticles (nTiO2) were incorporated in different contents into the optimized film (Owvp). FTIR and 1H NMR confirmed the successful preparation of films. FE-SEM showed that nTiO2 was homogeneously distributed, with a size of about 25.78 nm for the film containing 5 wt% of nTiO2. XRD was used to study the film's crystallinity, and calculate the crystallite size of nTiO2 using Debye–Scherrer Equation. Thermal stability, by TGA, was improved while the water vapor permeability was reduced upon increasing the nTiO2 content. Color measurements showed that the nTiO2 incorporation didn't significantly affect the transparency. Elongation at break was decreased upon nTiO2 incorporation while tensile strength and Young's modulus were increased with increasing nTiO2 up to 3 wt% then begin to decrease. The nanocomposites exhibited significant UV-barrier properties and enhanced antimicrobial activity especially at high contents of nTiO2. Shelf-life studies on green bell pepper coated with the nanocomposite films showed excellent resistance to mass loss and spoilage during storage. The obtained data confirm the efficiency of the prepared nTiO2 nanocomposite films to extend the shelf-life of food.

Development of antibacterial carboxymethyl cellulose/chitosan biguanidine hydrochloride edible films activated with frankincense essential oil

This study aims to prepare binary edible films made from carboxymethyl cellulose (CMC) and chitosan biguanidine hydrochloride (CBg) activated with frankincense oil (FO). The interactions between CMC, CBg and FO were confirmed by FTIR. XRD showed that the addition of FO led to decreasing the crystallinity of CMC/CBg films. The water vapour permeability was reduced upon increasing the FO content. The presence of FO made the films brighter and didn't change their transparency as detected from the color measurements. The films exhibited better mechanical properties in the presence of FO as detected from the improved values of both tensile strength and elongation at break. The prepared films exhibited excellent antibacterial activity especially at high content of FO (5%). CMC/CBg/FO films might be used potentially in the production of edible films due to their excellent physical and antibacterial properties.

Carboxymethyl cellulose/sodium alginate/chitosan biguanidine hydrochloride ternary system for edible coatings

Chitosan biguanidine hydrochloride (CBg) was prepared as a novel multifunctional biodegradable polymer with antimicrobial and excellent water-solubility properties, and used as a crosslinker to prepare carboxymethyl cellulose (CMC)/alginate (A)/CBg edible coating. FTIR confirmed the successful preparation of CBg and CMC/A/CBg films. Wide-angle X-ray diffraction showed that the amorphous structure of CMC/A had some degree of order after CBg addition. The film thickness and solubility were decreased after CBg addition due to the formation of a dense crosslinked structure. CBg addition significantly improved the thermal properties of the films as detected from the calculated IPDT values from TGA curves. Water vapor permeability was reduced to 54% of the value of CMC/A when CBg was added by15 wt%. The addition of CBg didn't change the transparency of CMC/A films. The mechanical properties and antibacterial properties were significantly enhanced after the addition of CBg. CMC/A/CBg were coated on tomato fruits, and the shelf-life studies showed that the storage weight loss was significantly reduced, and the spoilage was inhibited after coating. These results suggest that CMC/A/CBg edible coating might be a promising candidate in food preservation industries.

Preparation, characterization and evaluation of chitosan biguanidine hydrochloride as a novel antiscalant during membrane desalination process

Scale deposition is considered as one of the most critical problems leading to permeate flux decline and deterioration of membrane surface in reverse osmosis (RO) desalination plants. This study aims to preparation of novel high effective scale inhibitor, chitosan biguanidine hydrochloride (CG), to inhibit the precipitation of calcium sulfate and carbonate onto the membrane surface. The modification of Chitosan by the guanidine group was to enhance its solubility in water, because chitosan as it is dissolves only in moderately acidic solutions. CG was synthesized and characterized by FTIR, 13C NMR and 1H NMR. The inhibition efficiency of our antiscalant was evaluated against CaSO4 and CaCO3 solutions at both static (induction time) and real application tests (cross-flow unit for 6 h). CG showed a good performance as scale inhibitor for CaSO4 and CaCO3 at about 10 and 15 mg·L−1 with flux decline of 2.6 and 5% in feed water, respectively. In addition, the induction time of precipitation of CaSO4 increased from 3 to 15 min with the addition of CG. SEM analysis at different magnifications for Cs and CG proved that CG strongly affects the morphology of the precipitated calcium sulfate and calcium carbonate leading to distortion of crystals.

Novel biodegradable and antibacterial edible films based on alginate and chitosan biguanidine hydrochloride

Novel bioactive edible films based on sodium alginate (A) and chitosan biguanidine hydrochloride (CG) with different weight percents were successfully prepared. 13C NMR and 1H NMR confirmed the successful guanidylation of chitosan. Fourier transform infrared confirmed the successful reaction between CG and A. The interaction between CG and A was confirmed through the reduction of the crystalline peaks of both CG and A as detected from their wide-angle X-ray diffraction. Thermogravimetric analysis confirmed that CG enhanced the thermal stability of films as detected from the calculated integral procedure decomposition temperature (IPDT) values. CG incorporation improved the mechanical properties of dry and wet samples. A/CG films exhibited a reduced water vapor permeability and good color properties. The antibacterial study proved that the prepared films showed a remarkable antibacterial killing ability. These results revealed that A/CG films could be an alternative candidate to be used as antibacterial edible films in food industries.

Chitooligosaccharide guanidine inhibits high glucose-induced activation of DAG/PKC pathway by regulating expression of GLUT2 in type 2 diabetic nephropathy rats

Previous results from our laboratory showed that chitosan biguanidine hydrochloride (CSGH) and chitooligosaccharide guanidine (COSG) could control glucose uptake by regulating the expression of glucose transporters (GLUTs) in vitro experiments. In this study, we try to delineate changes observed in activation of diacylglycerol (DAG)/protein kinase C-β(PKC-β) pathway and GLUT2 in kidney. STZ-induced diabetic rats were administered COSG via daily intra-gastric gavage for 8 weeks. Obviously, COSG significantly attenuated fasting blood glucose and blood glucose level by modulating the over-expression of GLUT2 and the level of DAG as well. Immunohistological examination revealed that factors such as PKC-β and transforming growth factor-β (TGF-β) diminished to various extents after treatment with COSG, which impinged on the synthesis of extracellular matrix (ECM) components like fibronectin (FN). As a result, high glucose-induced activation of DAG/PKC pathway is inhibited, which is associated with the concentration of glucose controlled by the expression of GLUT2 with the treatment of COSG.

Synthesis, characterization and antimicrobial activity of biguanidinylated chitosan-g-poly[(R)-3-hydroxybutyrate

Chitosan biguanidine hydrochloride (ChG) and low molecular weight poly[(R)-3-hydroxybutyrate] (PHB) were successfully prepared to overcome the solubility problem of chitosan and PHB and also to enhance antimicrobial activity of chitosan. The graft copolymers based on ChG and PHB (ChG-grafted PHB) were then prepared via condensation reaction of the carboxylic groups of PHB with the amino groups of ChG. These graft copolymers swell in water. The prepared graft copolymers were characterized by FTIR, 1H NMR, X-ray diffraction (XRD) and thermal analyses (TGA and DSC). TGA and DSC results revealed that the thermal stability and crystallinity of the graft copolymers were found to increase as the content of PHB increased. The antimicrobial activity of both ChG and ChG-grafted PHB, against Streptococcus pneumoniae, Bacillus subtilis, Escherichia coli (as examples of bacteria) and Aspergillus fumigatus, Geotricum candidum and Syncephalastrum recemosum (as examples of fungi), were tested. Among them, ChG and ChG-grafted PHB with the highest grafting percent investigated showed to possess relatively higher antimicrobial activity with low MIC values in the range of 0.49–3.90μgmL−1.

Microwave-assisted synthesis of chitosan biguanidine hydrochloride and its regulation on InsR and GLUT2 in insulin resistant HepG2 cells

CSGH increased glucose consumption of HepG2 cells by accelerating the expression of InsR and inhibiting the high-insulin-induced over-expression of GLUT2.

Synthesis, characterization, and biological activity of cross-linked chitosan biguanidine loaded with silver nanoparticles

Chitosan biguanidine hydrochloride (ChG) and glutaraldehyde cross-linked chitosan biguanidine (CChG) were synthesized and characterized by Fourier transform infrared spectroscopy, 1H NMR and 13C NMR, X-ray diffraction, scanning electron microscopy (SEM) and thermal analyses (TGA and DTA). The results showed that ChG and CChG had a more amorphous structure than that of chitosan, and their thermal stability were slightly lower than that of chitosan. Colloidal silver nanoparticles (AgNPs) were prepared using borohydride reduction method and then investigated as fillers in partially cross-linked chitosan biguanidine. The obtained nanoparticles were uniform and spherical with average size of 9.6 ± 0.5 nm. The prepared CChG/AgNPs composites were characterized for their morphology, thermal properties, cytotoxicity and antimicrobial activity. The SEM images showed that the AgNPs are well imbedded in the CChG matrix. The thermal stability of CChG was improved with incorporation of AgNPs. The CChG and CChG/AgNPs showed less cytotoxicity to breast cancer cells (MCF-7). Compared with chitosan and CChG, the ChG and CChG/AgNPs showed better antimicrobial activity against Streptococcus pneumoniae and Bacillus subtilis as Gram-positive bacteria, Escherichia coli as Gram-negative bacteria and Aspergillus fumigatus, Geotricum candidum and Syncephalastrum recemosum as fungi.

Microwave‐assisted synthesis of chitosan biguanidine hydrochloride and its antioxidant activity in vitro

ABSTRACTChitosan biguanidine hydrochloride (CSGH) was synthesized by guanidinylation of chitosan hydrochloride (CSH) under microwave irradiation and characterized by Fourier transform infrared spectroscopy, gel permeation chromatography, and element analysis. The antioxidant activity of CSGH was evaluated by both chemical and cellular methods. The results showed that CSGH was better than CSH but slightly inferior to ascorbic acid (Vc) for scavenging 2,2‐diphenyl‐1‐picryl‐hydrazyl (DPPH) free radicals, and the DPPH• scavenging ability of CSGH was dose‐dependent. However, cell experiments indicated CSGH had a superior repairing effect on oxidatively damaged cells. The intervention of CSGH could excellently recover the cell morphology, decrease the level of malondialdehyde, and enhance the activity of superoxide dismutase and glutathione peroxidase. CSGH could be a potential antioxidant reagent, and its antioxidant activity was reflected not only in scavenging the free radicals but also in regulating the oxidation/antioxidation balance of damaged cells. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43570.

Adsorption of Chromium(VI) from Aqueous Solution Using a Novel Chitosan Biguanidine

A novel chitosan-modified adsorbent (glutaraldehyde cross-linked chitosan biguanidine (GCB)) was prepared by the cross-linked reaction of glutaraldehyde with chitosan biguanidine hydrochloride. The adsorbent was characterized by Fourier transform infrared, scanning electron microcopy, and thermogravimetric analysis. The effects of various variables for the adsorption of Cr(VI) on GCB were systematically investigated. The results showed that the equilibrium adsorption behavior of Cr(VI) on GCB had the best agreement with the Langmuir isotherm model and the maximum adsorption capacity was calculated as 202.4 mg · g−1 for Cr(VI) with pH 3.6 at 30°C. The thermodynamic results indicated that the adsorption was an endothermic and spontaneous chemical process. The coexisting for the adsorption of Cr(VI) on GCB had greater inhibitory effect than , Cl−. GCB could effectively remove the Cr(VI) from the aqueous solution and the GCB can be reused.

Effect of microwave curing on antimicrobial activity of chitosan biguanidine hydrochloride treated wool fabrics

An alternative microwave curing system was used for curing chitosan biguanidine hydrochloride treated wool fabric to study its effects on the antimicrobial activity of the fabric. The effects of microwave curing at different irradiation power and treatment time on the physical properties of wool fabrics and the adsorption rate of chitosan biguanidine hydrochloride on wool fabrics has been examined. Comparisons were made between conventionally cured wool fabric and microwave‐cured wool fabric treated with chitosan biguanidine hydrochloride. The influence of microwave curing on the efficiency of crosslinking was studied by using scanning electron microscopy and Fourier transform infrared spectroscopy. Microwave‐cured samples showed a higher degree of crosslinking than conventionally cured samples without high losses in strength properties. Antimicrobial properties and the durability of the finish after repeated laundering results also supported the higher degree of crosslinking that occurred in microwave curing.

Effect of Chitosan Biguanidine Hydrochloride on Textile Properties of Antheraea Pernyi Silk

In order to improve the water-solubility of chitosan, chitosan biguanidine hydrochloride was synthesized by modified chitosan with dicyandiamide in the presence of hydrochloric acid. The guanidinylation chitosan was then applied to Antheraea pernyi (A. pernyi) silk fabric in the presence of 1,2,3,4-butane tetracarboxylic acid with sodium hypophosphite as catalyst. Studies on the effect of chitosan biguanidine hydrochloride treatment on morphology and textile properties of A. pernyi silk fiber and fabric have been conducted. The changes in the morphological structure have been monitored by scanning electron microscope. The changes in some of textile properties including wrinkle recovery angles and bacterial reduction owing to the treatment have also been investigated. It has been found that the surface of A. pernyi silk gets rough. The wrinkle-resistant performance improved, and the antibacterial activity of the treated A. pernyi silk fabric against E. coli was more than 99%.

Preparation of Chitosan Biguanidine Hydrochloride and Application in Antimicrobial Finish of Wool Fabric

Chitosan biguanidine hydrochloride (CGH) has been synthesized by the guanidinylation reaction of chitosan with dicyandiamide. Its synthetic mechanism was discussed. The structures of CGH were characterized by FT-IR and 13CNMR. In this study, we used citric acid (CA) as a crosslinking agent, mixed with CGH to perform a pad-dry-cure treatment on wool fabric to study its antimicrobial effects with the help of scanning electron microscopy (SEM). The result showed that there was no obvious sign that CGH adhered to the wool fabric if the wool fabrics were not oxidized by hydrogen peroxide. The surface crosslinks of the oxidized wool fibers were relatively coarse, which beneficial for the antimicrobial and antiseptic effects of the wool fabrics. Key words: chitosan biguanidine hydrochloride; synthesis; wool; antimicrobial

Synthesis and Characterization of Chitosan Biguanidine Hydrochloride under Microwave Irradiation

Chitosan biguanidine hydrochloride was synthesized by reacting chitosan with dicyandiamide under microwave irradiation. The influence of reaction temperature, reaction solvent and microwave heating time was studied, and optimal conditions were identified. The representative microwave synthesized chitosan biguanidine hydrochloride was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction measurement, taking chitosan as a reference. The solubility pH for the chitosan biguanidine hydrochloride with different substitution degrees was monitored. The antimicrobial activities of chitosan biguanidine hydrochloride were measured by means of the minimal inhibition concentration (MIC). In vitro antimicrobial activity of guanidinylated chitosans with different substitution degrees were evaluated against staphylococcus aureus, bacillus subtilis, escherichia coli and pseudomonas aeruginosa. The results show that the microwave irradiation method can increase the reaction rate by twelve times over the conventional method. Chitosan biguanidine hydrochloride are effective of bacteriostasis, compared with chitosan, guanidinylated chitosan had much better antibacterial activity. The antibacterial activity of chitosan biguanidine hydrochloride derivative enhanced with increasing substitution degrees of guanidinylated chitosan.