Chitosan Blend Research Articles

Three-component antibacterial membrane of poly(butylene carbonate), poly(lactic acid) and chitosan prepared by electrospinning

ABSTRACTThe poly(butylene carbonate) (PBC)/poly(lactic acid) (PLA)/chitosan (CS) blend nanofibre membranes have been prepared by electrospinning. Trifluoroacetic acid was found to be the best co-solvent for PBC/PLA/CS blend. The nanofibre microstructure was studied by scanning electron microscopy and showed good fibre diameter distribution when CS content was 0.08%. As the content of CS increases, the diameter of the fibres became finer. Fourier transform infrared spectrometer shows that there was no chemical reaction between the PBC and PLA, and CS was successfully added to the PBC/PLA. Thermogravimetry analysis indicates that the addition of CS can improve the thermal stability of the PBC/PLA membrane. The PBC/PLA/CS membranes exhibit good improvements in mechanical property. The tensile strength of nanofibres increases with the addition of 0.04% CS but reduces with further addition of 0.12% g CS. The PBC/PLA/CS membranes also have an excellent hydrophilic property. As the amount of CS increases, the contact angle gradually decreases. The PBC/PLA/CS membranes showed high antimicrobial activity against Escherichia coli and Staphylococcus aureus in vitro test.

Effect of polyvinyl alcohol/chitosan blend ratios on morphological, optical, andthermal properties of electrospun nanofibers

In this study, the electrospinning method was used to prepare polyvinyl alcohol (PVA)/chitosan (CS) blend nanofibers from their solutions. The effect of blend ratios (PVA/CS: 1%, 3%, 5%, and 7% (w/w)), applied voltage, and flow rate on the morphological, optical, and thermal properties of electrospun nanofibers were investigated by scanning electron microscopy (SEM), fluorescence and UV-Vis spectroscopies, and thermogravimetric analysis (TGA), respectively. Fourier transform infrared spectroscopy analysis indicated the existence of related functional groups of both PVA and CS in the electrospun fibers. During the electrospinning process, the maximum possible ratio of CS was 7% (w/w). SEM images indicated that more flat nanofibers were synthesized at lower flow rates, but the shape of the fibers was more circular at higher flow rates. On the other hand, an increase in CS ratio, flow rate, and applied voltage caused a decrease in the transmittance values of the fibers while samples including higher concentrations of CS showed lower emission intensities. Furthermore, the thermal properties of the electrospun fibers were developed by incorporation of a high amount of CS.

In situ thermo-co-electroresponsive mucogel for controlled release of bioactive agent

The purpose of this work was to develop an in situ thermosensitive electro-responsive mucoadhesive gel loaded with bioactive agent (nanocomposite) meant for nose to brain delivery in a controllable manner when electric stimulation is applied. Nanocomposite was developed using a combinatorial blending of chitosan, hydroxypropylmethylcellulose, pluronic F127 and polyaniline which was then loaded with BCNU-Nano-co-Plex (the bioactive agent). The nanocomposite was a liquid at room temperature but formed an in situ mucogel at a temperature of 27.5 ± 0.5 °C. Furthermore, the nanocomposite possessed a redox element which makes it responsive to electrical stimulation (ES). The stimuli responsiveness enabled the formulation to release the bioactive agent when electrical potential was applied and demonstrated a desired 10.28% release of nanoparticles per application cycle. The results further revealed pore formation within the formulation which accommodated the loaded nanoparticles. The release profile also demonstrated a pulsatile release of the bioactive material when subjected to ES. This formulation may therefore be useful as a nose to brain drug delivery system that can be modulated to deliver bioactive agents to the brain via electro-actuation in an “on-off” drug release kinetics by means of an external ES for a controlled nose-to-brain delivery.

Biomimetic fabrication of mineralized composite films of nanosilver loaded native fibrillar collagen and chitosan

Silver nanoparticles loaded fibrillar collagen-chitosan matrix (CC) was prepared by biomimetic approach by blending silver nanoparticles (tAgNPs), collagen fibril and chitosan hydrogel followed by cross-linking and biomineralization. Electron micrograph showed that the surface of the composites exhibited native fibrillar morphology of collagen and their cross-section revealed layer-like arrangement of native fibrillar collagen. The mineralized composites exhibited surface mineralization of calcium phosphates incorporated with magnesium. FT-IR ATR analysis revealed the uniform blending of collagen and chitosan without any chemical interaction between them. XRD analysis showed incorporation of silver nanoparticles and lamellar structure of collagen and chitosan. The mechanical property of the dry composite film showed increase in tensile strength with the addition of chitosan and raised to 4.6 fold in M-CC4 composite. The incorporation of chitosan in M-CC3 led to 2.2 fold increase in mineralization as confirmed by the TGA analysis. Contact angle analysis revealed the hydrophilic nature of the composite. Hemolysis analysis of the composites verified the hemocompatible nature of composites with hemolysis < 5%. MTT assay for the composites was carried by seeding MG-63 cells and indicated cell viability > 80%. Antibacterial activity analysis showed the percent growth inhibition of about 27% and 37% for S. aureus and E. coli respectively. The prepared composite would possess silver nanoparticles loaded collagen fibril in the native state and the formed biomineral will be similar to the bone mineral. Hence the fabricated composite -could be used as a biomaterial for bone tissue engineering applications.

Preparation, characterization and stability evaluation of ionic liquid blended chitosan tripolyphosphate microparticles

Recently, drug delivery systems are facing several shortcomings which demand for the development of new formulations. A new drug–solvent systems may improve the characteristics and sustained release of drugs. Investigations in this domain revealed the significance of Ionic Liquids (ILs) as active pharmaceutical ingredients for pharmaceutical applications. ILs–drug assisted carriers exhibit many unique and attractive properties which are lacking in their conventional counterparts. In this work, Chitosan (CS), a natural polymer was blended with an ammonium based IL, Tetramethylammonium hydroxide (TMAOH), and microparticles (MPs) of CS–TMAOH–TPP were synthesized by cross–linking with sodium tripolyphosphate (TPP) using ionic gelation method. The addition of TMAOH to CS enhanced the stability of MPs without affecting the particle size. FTIR analysis confirmed the structural changes whereas the FE-SEM analysis showed almost similar sizes of freeze–dried MPs as determined by Zetasizer. The morphology of the CS–TMAOH–TPP MPs was mostly similar to CS–TPP MPs. The Thermogravimetric analysis indicated that these MPs exhibit good thermal resistance. Moreover, the DSC and XRD analysis of the prepared MPs were conducted to analyze thermograms and crystallographic structure respectively. Overall, the present synthesized CS–TMAOH–TPP MPs are more stable than CS–TPP MPs, which will be useful for drug delivery applications.

Chitosan Imparts Better Biological Properties for Poly(ε-caprolactone) Electrospun Membranes than Dexamethasone

Poly(e-caprolactone), an aliphatic polyester with biodegradability and cytocompatibility, has been used to create scaffolds for tissue engineering purposes. However, the hydrophobicity and low water absorptivity of poly(e-caprolactone) reduce cell anchorage on their membranes. Here, poly(e-caprolactone)-based scaffolds were prepared by electrospinning of poly(e-caprolactone)-chitosan blend, and poly(e-caprolactone)-dexamethasone solution. Chitosan and dexamethasone play an essential role to increase the scaffolding performance of poly(e-caprolactone)-based electrospun membranes. A poly(e-caprolactone) membrane without chitosan and dexamethasone did not provide satisfactory results to promote cell culture of adipose mesenchymal stem cells (AMSCs). Compared to the poly(e-caprolactone)-dexamethasone surface, poly(e-caprolactone)-chitosan membrane imparts better cytoskeletal reorganization, and cell spreading, increasing the strength of cell attachment. Also, poly(e-caprolactone)-chitosan composite provides strong antimicrobial activity against Pseudomonas aeruginosa (ca. 90% inhibition). Therefore, the poly(e-caprolactone)-chitosan composite is a better alternative to treat skin diseases and promote skin regeneration than conventional approaches based on dexamethasone.

Preparation and Characterization of Thin Conductive Nanocomposite Film from Dispersed Multiwall Carbon Nanotubes Reinforced Chitosan/Polyvinyl Alcohol Blend

In this study, surfactant dispersed MWCNTs were introduced as nanofillers into poly (vinyl) alcohol (PVA) and Chitosan (Cs) blend (ratio 50:50 wt%, optimized) by solution casting method to fabricate PVA/Cs/MWCNTs nanocomposite films. These nanocomposites were subjected to different characterization to study the variation of properties with different amount of MWCNTs loading. Various techniques, such as Optical microscopy (OM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA, DTGA), differential scanning calorimetry (DSC), impedance analyzer (IA), scanning electron microscopy (SEM) and universal testing machine (UTM) were used to study the physicochemical, morphological, electrical and thermo-mechanical properties of the nanocomposite films. The experimental results of FTIR illustrated that strong interaction among MWCNTs, Cs and PVA facilitated the crystallization of PVA and prevented the agglomeration of MWCNTs in the composite film. Tensile strength of the nanocomposite containing 1 wt% MWCNTs increased by 61.51% and elongation at break decreased by 20.07% in comparison to that of pure PVA/Cs blend film. Similarly, the conductivity of the nanocomposite containing 1 wt% MWCNTs was highest at 40V with the value of 1.99 x 103 S/cm.

Investigation of the blends of chitosan and tragacanth as potential drug carriers for the delivery of ibuprofen in the intestine

This study provides a new potential hydrogel for the intestinal delivery of ibuprofen.

Edible Chitosan Films and Their Nanosized Counterparts Exhibit Antimicrobial Activity and Enhanced Mechanical and Barrier Properties.

Chitosan and chitosan-nanoparticles were combined to prepare biobased and unplasticized film blends displaying antimicrobial activity. Nanosized chitosans obtained by sonication for 5, 15, or 30 min were combined with chitosan at 3:7, 1:1, and 7:3 ratios, in order to adjust blend film mechanical properties and permeability. The incorporation of nanosized chitosans led to improvements in the interfacial interaction with chitosan microfibers, positively affecting film mechanical strength and stiffness, evidenced by scanning electron microscopy. Nanosized or blend chitosan film sensitivity to moisture was significantly decreased with the drop in biocomposite molecular masses, evidenced by increased water solubility and decreased water vapor permeability. Nanosized and chitosan interactions gave rise to light biobased films presenting discrete opacity and color changes, since red-green and yellow-blue colorations were affected. All chitosan blend films exhibited antimicrobial activity against both Gram-positive and Gram-negative bacteria. The performance of green unplasticized chitosan blend films displaying diverse morphologies has, thus, been proven as a potential step towards the design of nontoxic food packaging biobased films, protecting against spoilage microorganisms, while also minimizing environmental impacts.

Lignin-chitosan blend for methylene blue removal: Adsorption modeling

In this work, a comprehensive comparative analysis of various approaches for the modeling of the adsorption process was carried out to understand the adsorption isotherm and kinetics. The evaluated isotherm models included Langmuir, Freundlich, Dubinin–Radushkevich, Tempkin, Flory–Huggins, Hill, Redlich–Peterson, Sips, Toth, Koble–Corrigan, Khan, Radke–Prausnitz, Brunauer–Emmett–Teller, Frenkel–Halsey–Hill, MacMillan–Teller, Harkins–Jura, Halsey, Henderson, Fritz–Schluender, Vieth-Sladek, Valenzuela-Myers, Jovanovic, Baudu and Elovich. The evaluated kinetic models included pseudo-first-order, pseudo-second-order, Avrami, Adsorption kinetic and Bangham. For a detailed comparison, the experimentally measured adsorption data of methylene blue from water effluent on a lignin and chitosan blend were used. It was demonstrated that current kinetic models and isotherms provide some correlative method and view to the adsorption data that are useless without prior experimental data. It was revealed that the best results were obtained for Langmuir-1 form isotherm and the worst one was obtained for Harkins–Jura isotherm. In terms of kinetics, the linearized Form 2 of the pseudo-second-order indicated better goodness of fit to the experimental kinetic data.

Preparation and characterization of novel eggshell membrane-chitosan blend films for potential wound-care dressing: From waste to medicinal products

A series of different eggshell membrane (ESM) and chitosan (CS) blend films (ESM/CS) were prepared for wound-care dressing. The appearance, transparency and microstructure of the films were characterized. Several wound care-related properties such as the film integrity in solution, pH, protein (BSA) and wound fluid absorption capacity as well as the antibacterial property of ESM/CS films were evaluated. The blend films were more stable than CS film after 95 h of incubation in solution. The integrity of the blend films improved significantly at the cost of a small insignificant decrease in wound fluid absorption capacity. Besides, the blend films provided an acidic environment (pH = 5.86) for wound healing. The swelling properties of ESM contributed significantly to the increase of BSA absorption capacity of the blend films (from 46.57 mg/g of CS film to 61.07 mg/g of blend film) and helped absorb more nutrients to promote the proliferation and migration of fibroblasts. Addition of CS to ESM also enhanced the antibacterial activity of the films significantly. The results indicated that the EMS/CS blend films with 0.01 g ESM/mL CS solution showed the highest high potential to be used as a wound-care dressing for humans as well as animals.

Plasticized and plasticizer free lithium acetate doped polyvinyl alcohol–chitosan blend solid polymer electrolytes: Comparative studies

In this work, two systems (plasticized and plasticizer free) of polyvinyl alcohol (PVA)–chitosan blend based solid polymer electrolytes containing lithium acetate (LiOAc) are successfully prepared through solution casting method. In Fourier transform infrared (FTIR) spectroscopy studies, the changes in peak position of amine and hydroxyl band signify the saltpolymer and plasticizer-salt-polymer interactions. The room temperature conductivity of each electrolyte is investigated by impedance analysis in the frequency range of 50 Hz – 1 MHz. Upon addition of 30 wt.% LiOAc, a conductivity of (6.46 ± 1.80) × 10−5 S cm−1 is achieved. The conductivity increases to (1.15 ± 0.19) × 10−3 S cm−1 with the addition 70 wt.% ethylene carbonate (EC). The temperature dependence of conductivity is found to follow Vogel-Tammann-Fulcher (VTF) rule. From the VTF plot, the glass transition temperature (Tg) was analyzed and the highest conducting electrolyte is found to possess the lowest Tg value.

A Facile Approach towards Fabrication of Electrospun Nanofibrous Mats based Multicompartment Wound Dressing Fabric

We have designed an efficient wound dressing fabric consisting of physically attached multicompartment (three layers) electrospun nanofibrous mats. Electrospining technique enables abundant porosity and large surface area into the fabric, ensuring enhanced water absorption and cell respiration purposes. Blend of water insoluble, biocompatible, antifungal, bactericidal, and glutinous chitosan with flexible polyethylene oxide (PEO) and herbomettalic mica has been used as the inner layer. Oxygen permeable, tissue compatible, and flexible thermoplastic polyurethane (TPU) has been used as the outer layer. Using some facile chemical approaches, blends of natural polysaccharide pullulan/polyvinyl alcohol (PVA), and in situ polymerized poly (acrylic acid-co-acrylamide)/PVA have been synthesized to fabricate the superabsorbent polymeric materials (SPM) based middle layers of the No. 1 and No. 2 dressings, respectively. The blend ratio, solution viscosity, and electrospinning conditions (i.e., voltage, injection rate, tip-to-collector distance, etc.) have been optimized to prepare each layers of the desired fabrics. Scanning electron microscope (SEM) images, water uptake measurements, and mechanical and thermal properties have been considered to characterize the fabric properties. Because of the more polar functional groups (i.e., -COOH, -CONH2, and -OH) and more crosslinking within the middle layer by glutaraldehyde, No. 2 fabric shows excellent mechanical property (i.e., tensile strength of > 11 MPa), faster (110 seconds) and higher (95%) fluid absorption efficacy, and better reusability (only 16% of water retention after drying for 7 days at room temperature) than No. 1 fabric. No. 1 fabric, in contrast, mainly consisting of H-bonding among the polymers having only -OH functional group, shows < 10 MPa of tensile strength, 75% fluid absorption within 150 seconds and poor reusability (27% of water retention).

Synthesis and Characterization of Poly(Vinyl Alcohol)-Chitosan-Hydroxyapatite Scaffolds: A Promising Alternative for Bone Tissue Regeneration.

Scaffolds can be considered as one of the most promising treatments for bone tissue regeneration. Herein, blends of chitosan, poly(vinyl alcohol), and hydroxyapatite in different ratios were used to synthesize scaffolds via freeze-drying. Mechanical tests, FTIR, swelling and solubility degree, DSC, morphology, and cell viability were used as characterization techniques. Statistical significance of the experiments was determined using a two-way analysis of variance (ANOVA) with p < 0.05. Crosslinked and plasticized scaffolds absorbed five times more water than non-crosslinked and plasticized ones, which is an indicator of better hydrophilic features, as well as adequate resistance to water without detriment of the swelling potential. Indeed, the tested mechanical properties were notably higher for samples which were undergone to crosslinking and plasticized process. The presence of chitosan is determinant in pore formation and distribution which is an imperative for cell communication. Uniform pore size with diameters ranging from 142 to 519 µm were obtained, a range that has been described as optimal for bone tissue regeneration. Moreover, cytotoxicity was considered as negligible in the tested conditions, and viability indicates that the material might have potential as a bone regeneration system.

Use of collagen/chitosan sponges mineralized with hydroxyapatite for the repair of cranial defects in rats

In traumatology, we encounter several clinical challenges that involve extensive bone loss primarily related to trauma, conditions that can be treated with autologous grafts. A good alternative is the use of synthetic biomaterials as substitutes. These polymers provide a suitable environment for the growth of new bone and vascular tissue, which are essential for repair. Collagen/hydroxyapatite composites have proven to be biocompatible and to behave mechanically. Furthermore, the addition of chitosan contributes to the formation of a three-dimensional structure that permits cell adhesion and proliferation, thus improving osteogenesis. The aim of this study was to evaluate bone formation during the repair of bone defects experimentally induced in the skull of rats and grafted with a polymer blend consisting of bovine tendon collagen and chitosan combined with hydroxyapatite. Thirty animals were used for the creation of a defect in the left parietal bone and were divided into three groups of 10 animals each: a control group without biomaterial implantation, a group receiving the blend of collagen and chitosan, and a group receiving this blend combined with hydroxyapatite. Each group was subdivided and the animals were sacrificed 3 or 8 weeks after surgery. After sacrifice, the skulls were removed for macroscopic photodocumentation and radiographic examination. The samples were processed for histological evaluation of new bone formation at the surgical site. Macroscopic and radiographic analysis demonstrated the biocompatibility of the blends. Histologically, the formation of new bone occurred in continuity with the edges of the defect, with the observation of higher volumes in the grafted groups compared to control. Mineralization of sponges did not stimulate bone neoformation, with bone repair being incomplete over the experimental period. In conclusion, mineralization by the addition of hydroxyapatite should be better studied. However, the collagen/chitosan sponges used in this study are suitable to stimulate osteogenesis in cranial defects, although this process is slow and not sufficient to achieve complete bone regeneration over a short period of time.

Quantum chemical calculations and molecular modeling for methylene blue removal from water by a lignin-chitosan blend

A comprehensive analysis of the molecular dynamics and quantum chemical calculation methods for methylene blue removal by adsorption were carried out. The experimentally measured adsorption data of methylene blue from water effluent on a novel lignin and chitosan blend were used to validate the modeling results. The method and required steps for application of quantum chemical calculations and molecular modeling techniques as the state of the art approach for predictive modeling and investigation of adsorption were provided, and the model findings were validated by comparing with the experimental data; close agreement between the results was observed. The conductor-like screening model (COSMO) approach was used for calculation of equilibrium concentration of solute at the adsorbent-solute interface. The results revealed that the approach is highly recommended as it provides an alternative assessment for feasibility analysis before any experiments to be undertaken, resulting in time and cost saving.

Biocompatible Porous Scaffolds of Chitosan/Poly(EG-ran-PG) Blends with Tailored Pore Size and Nontoxic to Mesenchymal Stem Cells: Preparation by Controlled Evaporation from Aqueous Acetic Acid Solution.

The preparation of porous films (average size variation from 1 to 32 μm) of a 1:1 blend of chitosan with poly(EG-ran-PG) by the controlled evaporation of water from a 2 wt % aqueous acetic acid solution is reported. Interestingly, the blend exhibited porosity that could be tailored from 1 to 32 μm with the temperature of preparation of the blend film. The powder X-ray diffraction, Fourier transform infrared, and differential scanning calorimetry analyses of the films suggested the formation of partially miscible blends. Temperature-induced phase separation of the blend appears to be the mechanism of pore formation. The tensile strength, cytotoxicity, and biocompatibility of the blend films for the growth of mesenchymal stem cells were assessed vis-a-vis chitosan. The 1:1 blend film was observed to lack cytotoxicity and was also viable for the growth of mesenchymal stem cells. The tensile properties of the 1:1 blend were superior to those of the chitosan film. The simple preparation of porous, nontoxic, and biocompatible films could find use as a scaffold in the growth of tissue, and especially bone tissue, in wound dressing, and in filtration if a better control over pore size is achieved.

Optical and electronic activities of biobased films of chitosan/POTE containing gold nanoparticles: Experimental and theoretical analyses

Biobased films consisting of blends of chitosan with poly(octanoic acid 2-thiophen-3-yl-ethyl ester) (POTE), a conducting polymer, and gold nanoparticles (AuNPs) were prepared, and their thermal, morphological and surface potential properties were studied. POTE was dissolved in THF and mixed with an acidified aqueous solution containing chitosan to obtain chitosan/POTE (CS/POTE) films by solution casting. To produce gold nanoparticles in the CS/POTE films (i.e., CS/POTE/AuNP films), an aqueous solution of KAuCl4 salt at fixed concentration was added to the initial chitosan solution. The fabricated biobased films were characterized by spectroscopic techniques (FT-IR and UV–visible), thermogravimetry, contact angle analysis, polarized light microscopy (PLM), field emission scanning electron microscope (FE-SEM) and scanning Kelvin probe force microscopy (SKPFM). The effects of varying POTE composition and the presence of gold nanoparticles in the films were analyzed. For example, the results indicated the existence of interactions between chitosan and POTE, and LPM studies revealed a predominantly amorphous nature of these biobased films. In addition, the optical and surface potential behaviors of the films were examined by UV–visible and KPFM techniques. From the UV–visible spectra, the optical band gaps were estimated for the samples, and their surface potential maps exhibited differences according to the composition of POTE and the presence of AuNPs. Finally, theoretical electronic calculations provided insight into the contributions of POTE and gold nanoparticles to the electronic activity of the films.

Preparation, characterization, and antimicrobial activity of poly(γ-glutamic acid)/chitosan blends

Biocomposites of poly(γ-glutamic acid) (PGA) were prepared by a two-screw extruder using chitosan (CS) as the block with glycerol and with/without water and acetic acid as additives. The influences of the CS content and various additives on the properties of PGA/CS blends were investigated. The results of mechanical tests demonstrated that the elongation at break of the blends decreased with increasing quality proportion of CS. Fourier transform infrared spectroscopy revealed that there were ionic interactions in the blends. Thermodynamic characterizations and dynamic mechanical analyses indicated that the glass-transition temperature of the blends decreased with increasing CS proportion and was obviously influenced by additives. X-ray diffractograms indicated that selecting a suitable solvent is beneficial to the blending of raw materials. Morphology analysis showed that the two kinds of substrates exhibited different miscibilities under different conditions. In addition, the antibacterial activities of the blends against Escherichia coli were not obvious because of their limited solubility. Therefore, the PGA/CS blends appear to have potential as a new biomaterial.

Physicochemical properties of scaffolds based on mixtures of chitosan, collagen and glycosaminoglycans with nano-hydroxyapatite addition

Scaffolds based on chitosan (CTS), collagen (Coll), and glycosaminoglycans (GAGs) mixtures with nano-hydroxyapatite (HAp) were obtained with the use of the freeze-drying method. They were characterized by different analyses, e.g. SEM images and mechanical testing. Moreover, swelling behavior and biocompatibility tests were carried out.The results showed that the scaffolds based on the blends of chitosan, collagen, and glycosaminoglycans with hydroxyapatite are stable in aqueous environment. SEM images allowed the observation of a porous scaffolds structure with the pores size ~250 μm. The main purpose of the research was to detect the influence of hydroxyapatite addition on the glycosaminoglycans-enriched scaffolds properties. The physicochemical properties as swelling and mechanical parameters were tested. The scaffolds structure was observed by SEM. Moreover, the preliminary assessment of scaffolds suitability for cell growth, human osteosarcoma cell line SaOS-2 was used. The obtained results indicate that the addition of hydroxyapatite improves the mechanical parameters and cells biological response of the studied materials.