Weight Ratio Of Chitosan Research Articles

Chitosan-coated poly(lactic-co-glycolic acid) perfluorooctyl bromide nanoparticles for cell labeling in 19F magnetic resonance imaging

Noninvasive therapeutic cell tracking methods in living animals are important for understanding cell function and fate in connection with cell therapy. Here we report a new particle system based on chitosan-coated poly(lactic-co-glycolic acid) perfluorooctyl bromide (PLGA PFOB) nanoparticles designed for 19F magnetic resonance imaging (MRI) cell tracking. Chitosan was adsorbed onto the PLGA PFOB nanoparticles through electric interactions, which led to an increase in the hydrodynamic size and a surface charge proportional to the coating weight ratio. Confocal laser scanning microscopy, flow cytometry analysis and 19F-MRI showed that to achieve the highest labeling efficiency in vitro, the optimal weight ratio of chitosan to the PLGA PFOB nanoparticles was 1:10 for human mesenchymal stem cells (hMSCs) and 1:100 for Raw 264.7 macrophages. In vivo19F-MRI showed that 19F labeled hMSCs remained at the injected site 24h after injection. Thus, this study validates that chitosan-coated PLGA PFOB nanoparticles have the potential to track cell migration in vivo.

Development and characterization of chitosan/hyaluronan film for transdermal delivery of thiocolchicoside

The objective of this study was the development of chitosan/hyaluronan transdermal films to improve bioavailability of thiocolchicoside. This approach offers the possibility to elude the first-pass metabolism and at the same time it is able to provide a predictable and extended duration of activity. Films were prepared by casting and drying of aqueous solutions containing different weight ratios of chitosan and hyaluronan and characterized for their physico-chemical and functional properties. In accordance with polymeric composition of films and, therefore, with the amount of the net charge after the complexation, films containing the same weight ratio of chitosan and hyaluronan showed lower water uptake ability with respect to films containing only one polymeric species or an excess of chitosan or hyaluronan. Moreover, the lower the hydration of the polymeric network, the lower is the drug diffusion through the films and its permeation through the skin. This study clearly confirmed that the selection of a suitable polymeric weight ratio and appropriate preparative conditions allows the modulation of film functional properties, suggesting that these formulations could be used as a novel technological platform for transdermal drug delivery.

Slow-release of famotidine from tablets consisting of chitosan/sulfobutyl ether β-cyclodextrin composites

An intermolecular complex formed from a 1:1 weight ratio of chitosan (CS, molecular weight 30kDa) and sulfobutyl ether β-cyclodextrin (SBE-β-CyD, degree of substitution 7) was less soluble than either of the original components. The release of famotidine from tablets composed of a simple mixture of CS and SBE-β-CyD is slower in media at pH 1.2 than at 6.8. Macroscopic observation of tablets and a kinetic analysis of release profiles suggested that, at pH 1.2, the drug was slowly released from the less-soluble CS/SBE-β-CyD complex formed on the surface of the tablet immediately after exposure to water, accompanied by the dissolution of the interpolymer complex and, ultimately, the erosion and disintegration of the tablet. In the case of the medium at pH 6.8, the formation of a gel by CS was the cause of the slow release, especially for CS/SBE-β-CyD tablets which were significantly gelated and both the diameter and thickness of the tablet had expanded. The in vitro slow releasing characteristic of the CS/SBE-β-CyD tablet was reflected in the in vivo absorption of the drug after oral administration to rats. These results suggest that a simple mixing of CS and SBE-β-CyD is potentially useful for the controlled release of a drug.

A thermosensitive chitosan/corn starch/β-glycerol phosphate hydrogel containing TGF-β1 promotes differentiation of MSCs into chondrocyte-like cells

Our previous study showed that thermosensitive chitosan/corn starch/β-glycerol phosphate (C/S/β-GP) hydrogel was an effective carrier for chondrocytes and their transforming factor, TGF-β1. In the present study, MSCs were grown in C/S/β-GP hydrogels as an effective tool for chondrocyte-like cell differentiation. The MSCs-encapsulated hydrogel was prepared by blending chitosan solution (1.70% w/v in 0.1 M HCl) with pregelatinized corn starch solution (1.70% w/v). The total final concentration of the blended polymers was 1.53% w/v, and the weight ratio of chitosan to corn starch was 4 to 1. The TGF-β1 (final concentration of 25 ng/mL) and 5 × 105 MSCs were added to 500 μL chitosan/starch solution. Finally, β-GP (60% w/v) was added to obtain 6.0% w/v final concentration. The C/S/β-GP hydrogel changed from a liquid at room temperature to a gel at 37 ± 2°C. It converted the fibroblast-like MSCs into spheroid cells. In hydrogels containing TGF-β1, these cells further differentiated into chondrocyte-like cells. This was shown by their expressions of type II collagen and aggrecan mRNA. Type I collagen mRNA was initially expressed but this disappeared by 6 weeks in culture suggesting a complete chondrocyte differentiation by that time. Type II collagen protein production was detected by immunohistochemistry and immunofluorescence, and successively increased after 4–6 weeks in culture. Neither the mRNA nor the collagen expression could be detected in the absence of TGF-β1. The data indicate that MSCs would be an appropriate chondrocyte precursor in conjunction with our hydrogel loading TGF-β1 which is able to sustain chondrocyte function.

Biodegradable chitosan-glycolipid hybrid nanogels: A novel approach to encapsulate fucoxanthin for improved stability and bioavailability

This study aimed to improve the stability and biological availability of carotenoid fucoxanthin (FUCO) encapsulated in chitosan (CS) – sodium tripolyphosphate (TPP) – glycolipid (GL) nanogels, prepared by ionic gelation method. Scanning Electron Microscopic analysis and Dynamic Light Scattering examination revealed smooth and spherical nanogels with size range of 200–550 nm in weight ratios of CS: TPP (2.5:1), CS: GL (1:0.5). The zeta potential values (+30 to +50 mV) indicate that CS-NGs with FUCO + GL were more stable than that of CS-NGs + FUCO with no GL (+15 mV). The Fourier Transform Infrared Spectroscopy (FTIR) showed an extensive hydrogen bonding interaction between the FUCO and CS. X-ray Diffraction revealed FUCO is distributed in a disordered (amorphous) state in CS-NGs. Encapsulation efficiency, loading capacity and the yield of CS-NGs with FUCO + GL were 90%, 47% and 70%, respectively which is, significantly higher, than that of CS-NGs + FUCO without GL. Stability studies illustrated that glycolipid offers enhanced FUCO stability (t1/2, 45 h) with CS-NGs compared to that of with no GL (t1/2, 15 h) and standard FUCO (t1/2, <5 h). The bioavailability of FUCO in vitro from CS-NGs with GL was higher (68%) compared to that of CS-NGs + FUCO without GL (51%), FUCO with GL (35.5%) and control (21.5%). In conclusion, the stability and bioavailability of FUCO was improved by nanoencapsulation of FUCO with CS + GL.

Antimicrobial fibers based on chitosan and polyvinyl-alcohol

A series of antimicrobial fibers with different weight ratio of chitosan (CS) and polyvinyl alcohol (PVA) were fabricated via a primarily industrialized trail of wet-spinning method, and the morphology and structure of the resulting fibers were studied with the aid of scanning electron micrography (SEM), infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The CP60 blend fiber (60 % chitosan content) was confirmed as the best optimal sample among the blend fibers owing to strong intermolecular hydrogen bonds between PVA and chitosan and showed the maximum mechanical, antistatic, moisture absorption/desorption properties. The CP60 also exhibited good antimicrobial effects against Escherichia coli and Staphylococcus aureus as the chitosan fiber and could be recommended as the alternative material for the wound dressing and the food packing.

Genipin-crosslinked chitosan/poly-l-lysine gels promote fibroblast adhesion and proliferation

Chitosan blends have been widely investigated to create biomaterials with desirable physicochemical and biological properties for tissue engineering applications. A recurring difficulty, however, has been to maintain their stability in an aqueous environment. The rationale behind this study was to demonstrate that genipin crosslinking can improve and maintain the stability of chitosan/poly-l-lysine (PLL) blends. Four gel formulations were prepared by varying the weight ratios of chitosan and PLL. Electron microscopy revealed that genipin crosslinking provided a more homogenous gel surface compared to uncrosslinked gels. Moreover, it was discovered that 3h was sufficient to stabilize the gels. In vitro studies using fibroblasts demonstrated that genipin-crosslinked gels enhanced fibroblasts’ attachment as compared to uncrosslinked gels. Moreover, cell viability was significantly improved by 1.6 times on 60:40 gels, and 6.5 times on 50:50 gels after crosslinking. Finally, proliferation was enhanced up to 5 times on 60:40 gels.

Adsorption study of an organo-arsenical with chitosan-based sorbents

In this study, chitosan-based copolymers were prepared at various weight ratios of chitosan (C) to glutaraldehyde (G): 1:1 (CG11), 2:1 (CG21), and 3:1 (CG31). The sorption properties of these copolymers were investigated with roxarsone in simulated aquatic conditions at pH 7 in phosphate buffer, similar to that found in poultry litter leachate. The relative sorption capacity (Qm; mmol/g) of the sorbents are listed in parentheses in descending order: CG11 (1.80)>CG31 (0.945)>CG21 (0.802)>chitosan (0.416). The sorptive properties of the copolymers are comparable to granular activated carbon (GAC), a standard carbonaceous sorbent material, where Qm=2.36mmol/g. The adsorption properties of phenolic adsorbates such as o-nitrophenol, p-nitrophenol, and roxarsone with the CG copolymers and GAC were investigated at various pH and compared with phosphate and carbonate buffer systems.

Optimized synthesis of glycyrrhetinic acid-modified chitosan 5-fluorouracil nanoparticles and their characteristics

The nanoparticle drug delivery system, which uses natural or synthetic polymeric material as a carrier to deliver drugs to targeted tissues, has a broad prospect for clinical application for its targeting, slow-release, and biodegradable properties. Here, we used chitosan (CTS) and hepatoma cell-specific binding molecule glycyrrhetinic acid to synthesize glycyrrhetinic acid-modified chitosan (GA-CTS). The synthetic product was confirmed by infrared (IR) spectra and hydrogen-1 nuclear magnetic resonance. The GA-CTS/5-fluorouracil (5-FU) nanoparticles were synthesized by combining GA-CTS and 5-FU and conjugating 5-FU onto the GA-CTS nanomaterial. The central composite design was performed to optimize the preparation process as CTS:tripolyphosphate sodium (TPP) weight ratio =5:1, 5-FU:CTS weight ratio =1:1, TPP concentration =0.05% (w/v), and cross-link time =50 minutes. GA-CTS/5-FU nanoparticles had a mean particle size of 193.7 nm, a polydispersity index of 0.003, a zeta potential of +27.4 mV, and a drug loading of 1.56%. The GA-CTS/5-FU nanoparticle had a protective effect on the drug against plasma degrading enzyme, and provided a sustained release system comprising three distinct phases of quick, steady, and slow release. Our study showed that the peak time, half-life time, mean residence time and area under the curve of GA-CTS/5-FU were longer or more than those of the 5-FU group, but the maximum concentration (Cmax) was lower. We demonstrated that the nanoparticles accumulated in the liver and have significantly inhibited tumor growth in an orthotropic liver cancer mouse model.

Electrospun chitosan–gelatin–polyvinyl alcohol hybrid nanofibrous mats: Production and characterization

To avoid using toxic organic solvents and surfactants, production of chitosan-based nanofibers usually requires a concentrated acetic acid solution as solvent. In this study, chitosan–gelatin–polyvinyl alcohol (PVA) hybrid nanofibrous mats were successfully fabricated using only a mild concentration (20wt%) of acetic acid by electrospinning. The optimum weight ratio of chitosan:gelatin:PVA was 2:2:4 which produced fiber diameters of around 150nm. The chitosan–gelatin–PVA hybrid nanofibrous mats were further reinforced by crosslinking using glutaraldehyde vapor for 12h. The crosslinked mats exhibited better stability and tensile strength (229.6±39.1N/g). The DSC thermograms indicated that good homogeneity of the nanofibrous mats was achieved. The cytocompatibility test revealed better proliferation of mesenchymal stem cells on the nanofibrous mats than on the sponges. Due to enhanced strength, stability and cytocompatibility of the mats, and a mild acid solution required, the electrospun chitosan–gelatin–PVA hybrid nanofibrous mats show excellent potential for tissue engineering-related applications.

Guided Bone Regeneration Using Chitosan-Collagen Membranes in Dog Dehiscence-Type Defect Model

The purpose of the present study was to compare a newly developed chitosan-collagen membrane (CCM) with a standard collagen membrane (SCM) regarding their effects on guided bone regeneration. The right mandibular premolars and first molar were extracted from 12 beagle dogs. Four months later, acute buccal dehiscence-type defects (4 × 3 mm in height and width) were surgically created after implant site preparation. The defects were randomly assigned to 4 different groups: CCM-1 (weight ratio of chitosan to collagen of 40:1), CCM-2 (weight ratio of chitosan to collagen of 20:1), SCM, and vehicle control. The dogs were sacrificed after 4, 8, and 12 weeks of healing for radiographic examination, histologic observation, and histometric analysis. The membrane-treated sites showed more bone formation than the control sites, although no statistically significant differences were found between the membrane-treated sites and the control sites for new bone-to-implant contact and new bone-filled area at any point. At 8 weeks, the new bone height for the membrane-treated sites was significantly greater statistically than that of the untreated group (P < .05). At 12 weeks, the CCM-1 group showed significantly greater new bone height (1.91 ± 0.25 mm) than the untreated group (1.20 ± 0.34 mm; P < .05). However, the CCMs did not show any statistically significant differences compared with the SCMs for any assessed parameter. The results of the present study have shown that the developed CCMs can enhance bone regeneration and could be a candidate for use in guided bone regeneration.

Preparation of microcapsules by complex coacervation of gum Arabic and chitosan

Gum Arabic–chitosan microcapsules containing a commercially available blend of triglycerides (Miglyol 812 N) as core phase were synthesized by complex coacervation. This study was conducted to clarify the influence of different parameters on the encapsulation process, i.e. during the emulsion formation steps and during the shell formation, using conductometry, zeta potential, surface and interface tension measurement and Fourier-transform infrared spectroscopy. By carefully analyzing the influencing factors including phase volume ratio, stirring rate and time, pH, reaction time, biopolymer ratio and crosslinking effect, the optimum synthetic conditions were found out. For the emulsion step, the optimum phase volume ratio chosen was 0.10 and an emulsion time of 15min at 11,000rpm was selected. The results also indicated that the optimum formation of these complexes appears at a pH value of 3.6 and a weight ratio of chitosan to gum Arabic mixtures of 0.25.

Physicochemical, Microstructural, and Antibacterial Properties of β‐Chitosan and Kudzu Starch Composite Films

This study investigated physicochemical, microstructural, and antibacterial properties of β-chitosan-kudzu starch composite films with addition of 0%, 20%, 60%, or 100% kudzu starch (w starch/w chitosan) in 1% chitosan solution. Molecular interactions between chitosan and kudzu starch and the crystal structure of the films were also determined. Adding 60% kudzu starch reduced water vapor permeability and solubility of pure β-chitosan film by about 15% and 20%, respectively, whereas mechanical strength and flexibility of the film were increased about 50% and 25%, respectively. Micrograph showed that β-chitosan film was totally amorphous, and the composite films generally became rougher with more starch added. Fourier transform infrared and X-ray diffraction spectra showed that the 2 film-forming components were compatible with each other. Pure β-chitosan film resulted in 9.5 and 11.5 log CFU/mL reduction in Escherichia coli and Listeria innocua based on plate count method, respectively. Addition of kudzu starch reduced the antibacterial activity of film, but still achieved 8.3 and 10.3 log CFU/mL reduction in E. coli and L. innocua, respectively when kudzu starch to chitosan weight ratio was 1:1. Reduced antibacterial activity might attribute to the interaction of amino groups in β-chitosan with the hydroxyl groups in kudzu starch. This study demonstrated that kudzu starch effectively improved water barrier of β-chitosan film, and the composite films retained strong antibacterial ability. One percent of β-chitosan containing 60% kudzu starch (w/w chitosan) composite films possessed better mechanical and water barrier properties than pure β-chitosan films, and showed strong antibacterial activity against both Gram-positive and Gram-negative bacteria. The films may be used as wraps or coatings to prolong the shelf life of different foods or other similar applications.

Stability Study of Chitosan-g-AM Inverse Emulsion

Graft copolymerization of chitosan and vinyl monomer (such as acryamide and acrylic acid) and application study of the copolymer used as papermaking additive were paid more and more attention in papermaking chemical industry. Chitosan and acrylamide(AM) monomer were graft copolymerizing in inverse emulsion. Several factors such as oil-water proportion, mass ratio of chitosan and AM, emulsifier types and ratio, and initiator concentration that affect the stability of inverse emulsion were elementarily studied. Stable latex can be gained when reaction condition was that the volume ratio of oil phase and water phase was 1:1, the weight ratio of chitosan and AM was 1:8, the initiator concentration was 0.8mmol/L, the dosage of emulsification agent was 8% of the oil phase weight and the weight ratio of 1227 and OP-10 was 1:1.

Stability Study of Chitosan-g-AM Inverse Emulsion

Graft copolymerization of chitosan and vinyl monomer (such as acryamide and acrylic acid) and application study of the copolymer used as papermaking additive were paid more and more attention in papermaking chemical industry. Chitosan and acrylamide(AM) monomer were graft copolymerizing in inverse emulsion. Several factors such as oil-water proportion, mass ratio of chitosan and AM, emulsifier types and ratio, and initiator concentration that affect the stability of inverse emulsion were elementarily studied. Stable latex can be gained when reaction condition was that the volume ratio of oil phase and water phase was 1:1, the weight ratio of chitosan and AM was 1:8, the initiator concentration was 0.8mmol/L, the dosage of emulsification agent was 8% of the oil phase weight and the weight ratio of 1227 and OP-10 was 1:1.

Synthesis and characterization of nanofiber webs of chitosan/poly(vinyl alcohol) blends incorporated with silver nanoparticles

Nanofiber webs of chitosan (CS)/poly(vinyl alcohol) (PVA) blends incorporated with silver nanoparticles (AgNs) were fabricated by two different methods: a refluxing method and an annealing method. We found that the characterization and antibacterial activity of AgNs depended on not only the fabrication methods but also the weight ratio of CS and PVA in the CS/PVA blend. The change in the size and number of AgNs due to the interaction between AgNs and CS, in turn, affected the antibacterial property of the non-woven webs. Non-woven webs of CS/PVA nanofibers containing AgNs that were fabricated by the refluxing method showed higher antibacterial ability against Escherichia coli than did the other types of non-woven webs. The morphology of the electrospun non-woven webs was observed by field emission scanning electron microscopy. The characterization of AgN formation on the surface of electrospun fibers was examined by transmission electron microscopy, attenuated total reflectance-Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy.

Chitosan/Fucoidan pH Sensitive Nanoparticles for Oral Delivery System

AbstractA rationally designed oral delivery carrier must overcome various significant barriers in the gastrointestinal (GI) tract prior to delivery to the bloodstream. One of these barriers is the low pH of the gastric medium in the stomach. The aim of this study is to create pH‐sensitive nanoparticles for oral drug delivery to protect drugs from deterioration. The nanoparticles were prepared by the positively charged chitosan (CS) and negatively charged fucoidan (F) through the ionic‐gelation method. The structures of CS/F nanoparticles were characterized by Fourier transform infrared spectroscopy, particle size analyzer and transmission electron microscopy. Results indicated that the CS/F nanoparticles were ionized to a diameter of 200‐300 nm at a pH of 1.2. The CS/F nanoparticles became larger and unstable as the pH increased. Curcumin (Cur), an antitumor drug, is encapsulated in CS/F NPs for in vitro release study. The encapsulated Cur was sustained released as the pH increased, especially when the weight ratio of chitosan to fucoidan was 1:1. According to the results mentioned above, CS/F nanoparticles are effective pH‐sensitive carriers, and they have a great potential application in an oral delivery system.

Novel hyaluronic acid–chitosan nanoparticles as non-viral gene delivery vectors targeting osteoarthritis

Gene therapy is a promising new treatment strategy for common joint-disorders such as osteoarthritis. The development of safe, effective, targeted non-viral gene carriers is important for the clinical success of gene therapy. The present work describes the use of hybrid hyaluronic acid (HA)/chitosan (CS) nanoparticles as novel non-viral gene delivery vectors capable of transferring exogenous genes into primary chondrocytes for the treatment of joint diseases. HA/CS plasmid–DNA nanoparticles were synthesized through the complex coacervation of the cationic polymers with pEGFP. Particle size and zeta potential were related to the weight ratio of CS to HA, where increases in nanoparticle size and decreases in surface charge were observed as HA content increased. The particle size and the zeta potential varied according to pH. Transfection of primary chondrocytes was performed under different conditions to examine variations in the pH of the transfection medium, different N/P ratios, different plasmid concentrations, and different molecular weights of chitosan. Transfection efficiency was maximized for a medium pH of approximately 6.8, an N/P ratio of 5, plasmid concentration of 4 μg/ml, and a chitosan molecular weight of 50 kDa. The transfection efficiency of HA/CS-plasmid nanoparticles was significantly higher than that of CS-plasmid nanoparticles under the same conditions. The average viability of cells transfected with HA/CS-plasmid nanoparticles was over 90%. These results suggest that HA/CS-plasmid nanoparticles could be an effective non-viral vector suitable for gene delivery to chondrocytes.

Study on Preparation under Microwave Radiation and Application of Chitosan Grafted Poly(acrylamide) Inverse Latex

Inverse emulsion graft copolymerization of chitosan and acrylamide monomer under microwave radiation was studied. It was shown that when the microwave radiation power was 300W, the microwave radiation time was 150S, the volume ratio of oil phase and water phase was 1:1, the weight ratio of chitosan and AM was 1:7, the initiator concentration was 0.67mmol/L, the dosage of emulsification agent was 7% of the weight of oil phase and the weight ratio of Span-80 and OP-10 was 6:4, stable inverse latex could be gained. A good dry strengthening effect had been obtained by applying the above mentioned latex in wheat straw pulp as the strengthening agent. The breaking length and tearing index of paper was respectively increased by 23.5% and 15.1% when the dosage of the graft copolymer latex was 0.6%.

Study on Preparation and Application as Organic Particulate Retention Agent of Chitosan-AM-DMDAAC Inverse Latex

Graft copolymerization of acrylamide (AM) and diallyl dimethyl ammonium chloride (DMDAAC) onto chitosan in inverse emulsion was studied. The effect on Zeta potential and average granularity of synthetic inverse latex of the main reaction conditions such as the proportion of cationic monomer in total monomers, concentration of potassium persulfate (KPS) used as initiating agent were investigated in detail. It was shown that when the weight ratio of chitosan, AM and DMDAAC was 1:6:2, KPS concentration was 4.0mmol/L, NaHSO3concentration was 2.0mmol/L, stable inverse latex which had optimal performance could be gained. Good retention effect was obtained when a novel organic microparticle retention system composed of the above-mentioned chitosan-AM-DMDAAC inverse latex and anicnic polyacryamide (APAM) was applied to the deink pulp. First Pass Retention retention percentage of deink pulp was improved from 83.2% to 95.0% with the organic microparticle retention system when the dosage of inverse latex was from 0 to 0.4% of absolute dry pulp.