Mixture Of Chitosan Research Articles

Controlled release behaviour and antibacterial effects of antibiotic-loaded titania nanotubes

Bacterial infections have been identified as the main cause of orthopaedic implant failure. Owing to their high antibiotic delivery efficiency, titania nanotubes loaded with antibiotics constitute one of the most promising strategies for suppressing bacterial infections. However, it is difficult to control the drug-release behaviour of such nanotubes. Although sealing the nanotubes with a polymer solution provides sustained release effects to a certain extent, it inevitably influences their initial antibacterial activity. This study reports on the controlled release of gentamicin sulphate (GS) from titania nanotube surfaces whereby their initial antibacterial activity remains unaffected. Titania nanotubes were fabricated via electrochemical anodization and loaded with GS through physical adsorption. Experimental results showed that this loading method is feasible and efficient. The GS-loaded titania nanotubes were further covered by a thin film comprising a mixture of GS and chitosan (GSCH). The release kinetics confirmed that the drug release could be controlled by this thin film. Moreover, such a film was shown to not only inhibit initial bacterial adherence owing to its strong antibacterial properties but also enhance cell viability. Thus, GS-loaded titania nanotubes coated with GSCH have considerable potential as biomaterials for preventing initial release and peri-implant infection in the field of orthopaedics.

Physicochemical characteristics of chitosan/Beetosan hydrogels modified with Aloe vera

Event Abstract Back to Event Physicochemical characteristics of chitosan/Beetosan hydrogels modified with Aloe vera Bożena Tyliszczak1, Katarzyna Bialik-Wąs1, Dorota Walczyk1, Sonia Kudłacik1, Anna Drabczyk1 and Agnieszka Sobczak-Kupiec2 1 Department of Chemistry and Technology of Polymers, Cracow University of Technology, Poland 2 Institute of Inorganic Chemistry and Technology, Cracow University of Technology, Poland Chitin is the second most abundant polysaccharide, next to cellulose. Currently, chitin is isolated mainly from main source marine invertebrates like crab, krill, shrimp, lobster and fungi. Alternatively, chitosan can be extracted from naturally died honeybees after wintering. Innovativeness of performed synthesis of active hydrogel matrices was application of beetosan derived from multistage purification of naturally died honeybees. Structure of extracted beetosan was evaluated by means of FT-IR (see Figure 1) and XRD diffractometry (Figure 2). Figure 1. FT-IR spectra of Beetosan and commercial chitosan. Fig. 2 XRD diffractograms of Beetosan and commercial chitosan. Synthesis of chitosan based hydrogels was performed applying UV light, PEGDA (700) as cross linking agent and 2-hydroxy-2-methylpropiophenone as photoinitiator. Prior to exposure to UV light, the mixtures of chitosan and beetosan were modified with addition of Aloe vera juice (5-35% wt), which allowed to receive hydrogel materials with enhanced therapeutic activity. Interestingly, Aloe vera juice is commonly determined as "natural therapeutics" and possesses wide spectrum of biomedical applications. Due to the presence of variable active substances with significant pharmacological activity, Aloe vera juice possesses valuable antibacterial, antioxidant, antifungal, antiseptic, antiviral and immunological properties. Moreover, due to antibacterial and antiseptic activity and ability to simulate growth of fibroblasts, Aloe vera juice constitutes an promising component of hydrogel matrices that can be applied to form active wound dressings[1]-[3]. The received hydrogel matrices that contain the Aloe vera juice were physicochemically analyzed by means of FT-IR. The influence of added Aloe vera juice on the three dimensional structure and surface morphology of received hydrogels was evaluated applying SEM. In addition, the swelling degree in water and solutions of salts with variable pH and the incubation studies in both distilled water and simulated body fluids were evaluated. In addition, the release of active substances form hydrogel matrix was performed in phosphate buffer saline at pH equal 7.4 and 4.0. The authors would like to thank the The National Centre for Research and Development (Grant no: LIDER/033/697/L-5/13/NCBR/2014) for providing financial support to this project

A resettable and reprogrammable biomolecular keypad lock with dual outputs based on glucose oxidase-Au nanoclusters-Prussian blue nanocomposite films on an electrode surface.

In this work, electrochromic Prussian blue (PB) films were electrodeposited on the surface of indium tin oxide (ITO) electrodes, and a dispersion mixture of glucose oxidase (GOD), chitosan (CS) and gold nanoclusters (AuNCs) was then cast on the PB surface to form CS-AuNC-GOD/PB nanocomposite film electrodes. The blue PB component in the films could be changed into its colourless reduced form of Prussian white (PW) upon application of -0.2 V. The addition of glucose to the solution would produce H2O2 with the help of GOD in the films and oxygen in the solution, which could oxidize PW back to PB. In the meantime, the fluorescence emission signal of the AuNCs in the films was greatly influenced by the form of PB/PW. Based on these properties, the amperometric current, fluorescence intensity and UV-vis absorbance of the film electrodes demonstrated potential- and glucose-sensitive ON-OFF behaviors. Thus, a 2-input/3-output biomolecular logic gate system with 3 different types of output signals and a 2-to-1 encoder were developed. Furthermore, a resettable and reprogrammable 3-input biomolecular keypad lock was established with fluorescence intensity and UV-vis absorbance as dual outputs, which greatly enhanced the security level of the keypad lock. This work reported for the first time an enzyme-based keypad lock with dual outputs, which might open a new avenue to design more complicated biomolecular keypad lock systems.

Effect of different molecular weight chitosans on the mitigation of acrylamide formation and the functional properties of the resultant Maillard reaction products

Mitigation of acrylamide formation and the functional properties of Maillard reaction products (MRPs) were investigated in a food model system. The system was composed of elements of mixtures and their combination including fructose, asparagine and different molecular weight chitosans. All solutions were heated, and then analyzed for acrylamide content, MRPs absorbance, pH, color, antioxidant capacity, antibacterial activity and kinematic viscosity. The fructose, asparagine and chitosan mixture had more MRPs compared to other mixtures. 1,1-Diphenyl-2-pricrylhydrazy (DPPH) radical scavenging activities, ferrous ion chelating abilities and reducing power results showed that all solutions containing a combination of two or three reactants had antioxidant capacities. Acrylamide content has a positive correlation with absorbance values at OD294 and OD420 but a negative correlation with the CIB L∗ value of a solution (p<0.01). Experimental results evidenced that low molecular weight (50–190kDa) chitosan can be used to mitigate the formation of acrylamide.

Effect of antimicrobial mixtures and modified atmosphere packaging on the quality of Argentine hake (Merluccius hubbsi) burgers

Abstract The combined effect of binary and tertiary antimicrobial mixtures of chitosan, nisin and sodium lactate at pH 5.50, modified atmosphere packaging (MAP) and refrigerated storage on the global quality of Argentine hake burgers was studied. Global quality was evaluated through microbiological (mesophilic, lactic acid and proteolytic bacteria), physicochemical (pH, total volatile basic nitrogen and trimethylamine) and sensory (odor) parameters during 30 days at 4 °C. Burgers free of antimicrobials and packed in air or in MAP were used as controls. A challenge test with Listeria innocua was also performed. Fish burgers stored in air showed a global quality lower than 5 days. MAP was able to extend fish burgers quality, but it was not able to control L. innocua's development. The addition of antimicrobials improved microbiological, chemical and sensory characteristics. Among the different tested combinations, the one containing chitosan, nisin and sodium lactate must be highlighted. This mixture extended microbiological, physicochemical and sensory quality of burgers to 30 days. Furthermore, it controlled the development of L. innocua throughout storage. This study showed that the use of the proposed tertiary mixture of antimicrobials combined with MAP represents a promising technique to extend the shelf-life and safety of refrigerated hake burgers.

Designing novel macroporous composite hydrogels based on methacrylic acid copolymers and chitosan and in vitro assessment of lysozyme controlled delivery

Designing structure and morphology of macroporous hydrogels is crucial for their applications in controlled release systems of macromolecular drugs. Macroporous hydrogels, consisting of methacrylic acid (MAA) and either acryl amide (AAm) or 2-hydroxyethyl methacrylate (HEMA) (1st network), were prepared for this purpose by cryogelation (single network cryogels, SNCs). Macroporous interpenetrating polymer network (IPN) hydrogel composites were then prepared by a sequential strategy, the 2nd network consisting of chitosan (CS) cross-linked with poly(ethyleneglycol) diglycidyl ether (PEGDGE) being generated by the sorption of a CS and PEGDGE mixture in the 1st network followed by cross-linking. A strong difference in the behavior of SNCs and IPN hydrogel composites was found during the loading and release of lysozyme (LYS) used as macromolecular drug model. Thus, while the amount of LYS loaded on SNCs was higher than that loaded on the IPNs, the release of LYS from SNCs occurred at pH 2, when the ratio between MAA and AAm was 50:50, and only at pH 1 when the ratio between MAA and AAm was 70:30. The 2nd network led to the decrease of the pore size of the IPNs, mainly when the initial concentration of monomers was 10wt/v%, but the presence of CS facilitates the LYS release from IPNs, mainly at a concentration of monomer of 5wt/v%, and when HEMA was used as nonionic comonomer.

Complex film of chitosan and carboxymethyl cellulose nanofibers

A polymer film composed of a mixture of chitosan (Ch) and carboxymethyl cellulose sodium salt (CMC) nanofibers was deposited on a glass surface. The thin film of the Ch–CMC mixture obtained was stable, and fibroblast adhesion to the film was lowest when the weight ratio of Ch to CMC was 4:6. The ζ-potential and contact angle of the mixture film indicated that a polyion complex of Ch and CMC was formed. The mechanical strength of the film composed of Ch–CMC nanofiber complexes was much higher than that of the film composed of Ch–water-soluble CMC complexes (non-nanofiber), likely because the entanglement of nanofibers was enhanced by electrostatic attractions. These results indicate that the charge-neutralized nanofiber film was highly effective in suppressing cell adhesion and therefore is a promising material for biomedical applications.

Tweaking the mechanical and structural properties of colloidal chitosans by sonication

Compared to the oil-derived plastics typically used in food packaging, biofilms of pure chitosan present serious moisture issues. The physical degradation of the polysaccharide with ultrasound effectively reduces the water vapor permeability in these films but, unfortunately, they also turn more brittle. Blending chitosans of different morphology and molecular mass (M) is an unexplored strategy that could bring balance without the need of incorporating toxic or non-biodegradable plasticizers. To this end, we prepared and characterized the mixtures of a high-M chitosan with the products of its own ultrasonic fragmentation. Biopolymer degradation was followed by dynamic light scattering (DLS) and the mechanical and structural characteristics of the mixtures were evaluated from different rheological methods and atomic force microscopy (AFM). The results indicate that, through the control of the sonication time and mixture ratio, it is possible to adjust the viscoelasticity and morphological aspect of the mixtures at intermediate levels relative to their individual components. In a more general sense, it is emphasized the importance of design and materials processing for the development of a novel generation of additive-free sustainable but functional bioplastics.

Iron casein succinylate-chitosan coacervate for the liquid oral delivery of iron with bioavailability and stability enhancement.

Iron casein succinylate (ICS) liquid oral preparation as iron supplement has uncomfortable taste after a long period of storage because of its stability, and poor bioavailability of iron compared to any other iron preparations. To improve the chemical stability of ICS and enhance the bioavailability of iron, chitosan-ICS nanoparticles (NPs) were prepared by complex coacervation method and stabilized with polyethylene glycol (PEG) 400. NPs were spherical (mean diameter of 830-1070nm) with positive charge (+30-60mV) depending on the composition of NPs. Addition of PEG400 (2 w/v %) increased the zeta potential (26-50%) and physical stability of chitosan-ICS NPs suspension. Also, NPs decreased iron release compared to ICS after 7-weeks of storage at 4°C. NPs markedly increased the permeability of iron in Caco-2 cell up to 32-38-fold compared to ICS, while physical mixture of chitosan and ICS increased the iron permeability only 2.5-fold. In summary, NPs improved the physicochemical stability and enhanced the transport of iron compared to other iron preparations in Caco-2 cell model. Thus, chitosan-ICS coacervate might be a promising candidate as a liquid oral iron delivery system for iron deficiency patients with stability and bioavailability enhancement.

Application of polyethylene glycol, cetrimide, chitosan and their mixtures on cotton muslin fabric to improve rot resistance, antimicrobial property and its salt-free reactive dyeing

In the present work, cotton muslin fabric is treated with eco-friendly antimicrobial agents in order to observe the effect of those chemicals on the rot resistance properties, physical appearance, important textile-related mechanical properties and dyeability with reactive dyes. The cotton fabric has been treated with polyethylene glycol (PEG 200), cetrimide and chitosan individually and their blends, in the presence of citric acid and sodium hydrogen phosphate as mixed catalyst to investigate the effect of such treatment on fabric properties of treated cotton mentioned above. Amongst all individual and combined applications of above said chemicals, it is observed that treatment with a mixture of chitosan and PEG is showing good result in terms of improvement in rot resistance performance and an optimum balance in other textile-related mechanical and appearance properties indicating lowest degradation against microbial attack. A series of experiments were undertaken with varying percentage of both the chemicals to arrive at the optimum ratio of mixture of PEG and chitosan and compared with such effect for treatment with conventional quaternary ammonium compound EPTAC. This treatment shows much balance results and also creates a newer provision of salt-free reactive dyeing of such treated/cationized cotton muslin fabric by unconventional reactive dyeing in acid bath after such chemical treatment/modifications.

Impact of pectin or chitosan on bulk, interfacial and antioxidant properties of (+)-catechin and β-lactoglobulin ternary mixtures

The interactions effect between (+)-catechin, β-lactoglobulin and two types of polysaccharides (pectin and chitosan) were studied at pH 4.Dynamic light scattering (DLS) revealed that pectin formed smaller complexes in the presence of (+)-catechin and β-lg, while chitosan presented a reduced number of populations with higher particle size. Dynamic interfacial data (obtained by a drop tensiometer) revealed that the complexes formed between pectin (+)-catechin and β-lg slowed down the β-lg migration to the oil/water interface; contrarily to the chitosan mixtures where protein migrated faster. The surface dilatational modulus of β-lg was ∼45 mN/m and increased to ∼60 mN/m when mixing with pectin and (+)-catechin, while the values of the surface dilatational modulus for the chitosan mixed interfacial films decreased to ∼35 mN/m. The free (+)-catechin content decreased 12% and 10% when interacting with pectin and chitosan, respectively, as compared to pure (+)-catechin. However, the (+)-catechin antioxidant activity were not affected by the interactions. Complexes formed between polyphenols, proteins and polysaccharides could be used as a good alternative to understand and consequently improve the phytochemicals stability in food matrices.

Accumulation of copper in gill, liver, spleen, kidney and muscle tissues of Clarias gariepinus exposed to the metal singly and with mixture of chitosan

Accumulation of copper in gill, liver, spleen, kidney and muscle tissues of Clarias gariepinus exposed to the metal singly and with mixture of chitosan

Optimization and Evaluation of a Chitosan/Hydroxypropyl Methylcellulose Hydrogel Containing Toluidine Blue O for Antimicrobial Photodynamic Inactivation.

Photodynamic inactivation (PDI) combined with chitosan has been shown as a promising antimicrobial approach. The purpose of this study was to develop a chitosan hydrogel containing hydroxypropyl methylcellulose (HPMC), chitosan and toluidine blue O (TBO) to improve the bactericidal efficacy for topical application in clinics. The PDI efficacy of hydrogel was examined in vitro against the biofilms of Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa). Confocal scanning laser microscopy (CSLM) was performed to investigate the penetration level of TBO into viable S. aureus biofilms. Incorporation of HMPC could increase the physicochemical properties of chitosan hydrogel including the hardness, viscosity as well as bioadhesion; however, higher HMPC concentration also resulted in reduced antimicrobial effect. CSLM analysis further demonstrated that higher HPMC concentration constrained TBO diffusion into the biofilm. The incubation of biofilm and hydrogel was further performed at an angle of 90 degrees. After light irradiation, compared to the mixture of TBO and chitosan, the hydrogel treated sample showed increased PDI efficacy indicated that incorporation of HPMC did improve antimicrobial effect. Finally, the bactericidal efficacy could be significantly augmented by prolonged retention of hydrogel in the biofilm as well as in the animal model of rat skin burn wounds after light irradiation.

Gelation and micellization behaviors of pluronic® F127 hydrogel containing poly(isobutylcyanoacrylate) nanoparticles specifically designed for mucosal application

The aim of this investigation is to combine the advantages of pluronic® F127 hydrogels and nanoparticles composed of poly(isobutylcyanoacrylate) (PIBCA) core coated with a mixture of chitosan and thiolated chitosan to design novel multifunctional formulation for mucosal application. Nanoparticles offer the advantage of being mucoadhesive while pluronic® F127 hydrogel allowed prolonged contact time onto mucosal surfaces. This work highlights an unprecedented comprehensive study on the effect of nanoparticles on gelation and micellization behaviors of pluronic® F127 using rheology and micro-calorimetry experiments. Results showed that presence of nanoparticles induced (i) smaller crystal peak of F127, (ii) a decrease of the enthalpy of F127 micellization and (iii) a non-reversibility of micelle formation (during heating ramp) and micelle melting (during cooling ramp). Together, these findings suggest that a part of F127 was not able to associate into micelles and the formation of mixed micelles containing F127 unimers and PIBCA/(chitosan/thiolated chitosan) copolymer and/or PIBCA homopolymer was suspected. The interaction of F127 unimers with nanoparticles resulted from their physical de-structuration as revealed by nanoparticle size measurement. In addition, we found that short polymerization duration of one hour induced more pronounced nanoparticle de-structuration. Twenty-four hour-polymerization of isobutylcyanoacrylate in the presence of chitosan and thiolated chitosan led to more stable nanoparticles when mixed with pluronic® F127.

RHEOLOGICAL STUDY OF GELS BASED ON CHITOSAN AND CARBON NANOTUBES

Chitosan/carbon nanotubes associations have applications in tissue regeneration. This study reports on the rheological characterization of gels prepared by the mixture of chitosan and single-walled carbon nanotubes (SWCN). Rheological characterization was used to understand the internal structure of gels. Frequency tests of chitosan/SWCN showed that gels have elastic behavior, and also an increment in SWCN concentration increases G´ modulus. Gels had an increase in viscosity values of more than 10 times as a function of SWCN concentration. The addition of carbon nanotubes modified the behavior of gels as observed by temperature results. For all gels prepared with SWCN, G´ is higher than G´´ in the temperature range studied. SWCN changes the tridimensional network of chitosan and a new chain arrangement is obtained.

Characterization of Silk Fibroin/Chitosan 3D Porous Scaffold and In Vitro Cytology.

Bone tissue engineering is a powerful tool to treat bone defects caused by trauma, infection, tumors and other factors. Both silk fibroin (SF) and chitosan (CS) are non-toxic and have good biocompatibility, but are poor biological scaffolds when used alone. In this study, the microscopic structure and related properties of SF/CS composite scaffolds with different component ratios were examined. The scaffold material most suitable for osteoblast growth was determined, and these results offer an experimental basis for the future reconstruction of bone defects. First, via freeze-drying and chemical crosslinking methods, SF/CS composites with different component ratios were prepared and their structure was characterized. Changes in the internal structure of the SF and CS mixture were observed, confirming that the mutual modification between the two components was complete and stable. The internal structure of the composite material was porous and three-dimensional with a porosity above 90%. We next studied the pore size, swelling ratio, water absorption ratio, degradation and in vitro cell proliferation. For the 40% SF-60% CS group, the pore size of the scaffold was suitable for the growth of osteoblasts, and the rate of degradation was steady. This favors the early adhesion, growth and proliferation of MG-63 cells. In addition to good biocompatibility and satisfactory cell affinity, this material promotes the secretion of extracellular matrix materials by osteoblasts. Thus, 40% SF-60% CS is a good material for bone tissue engineering.

Behaviour of cyanidin-3-glucoside, β-lactoglobulin and polysaccharides nanoparticles in bulk and oil-in-water interfaces

Particle size distributions as well the interfacial and rheological properties of the films at the oil/water interface were used to study the effect of the interacting system between β-lactoglobulin, cyanidin-3-glucoside and pectin or chitosan in buffer solutions. The particles obtained were smaller with cy-3-gluc-β-lg-pectin and had reduced polydispersity with cy-3-gluc-β-lg-chitosan. Based on time dependent surface pressure results, β-lg-pectin mixtures showed a slower increase at the beginning of the measurement, while β-lg-chitosan mixtures showed no differences with β-lg alone. Contrarily, dilatational properties increased for ternary chitosan mixtures, but they remained similar to the pure protein in ternary pectin mixtures. Cy-3-gluc interfacial properties were reduced by the presence of pectin and chitosan.The interactions between cy-3-gluc and the biopolymers that have been selected in the present work resulted in a lower content of free polyphenol, reduced antioxidant properties as well as free β-lg. The impact of this effect was more relevant when pectin was used.

Cell line-dependent cytotoxicity of poly(isobutylcyanoacrylate) nanoparticles coated with chitosan and thiolated chitosan: Insights from cultured human epithelial HeLa, Caco2/TC7 and HT-29/MTX cells

Nanoparticles composed of poly(isobutylcyanoacrylate) core coated with a mixture of chitosan and thiolated chitosan have already shown promising results in terms of mucoadhesion and permeation enhancement properties of pharmaceutical active drugs delivered via mucosal routes. In the present work, the cytotoxicity of these nanoparticles was first investigated using direct contact assay on undifferentiated human cervix epithelial HeLa cells. The results showed strong toxicity in HeLa cells for the two investigated concentrations 25 and 50μg/mL. The cytotoxic effect was mainly attributed to the poly(isobutylcyanoacrylate) core since no significant differences in nanoparticle cytotoxicity were reported when nanoparticle shell composition was modified by adding chitosan or thiolated chitosan. In contrast, lower nanoparticle toxicity was reported using human fully-differentiated enterocyte-like Caco-2/TC7, and fully-differentiated mucus-secreting HT-29/MTX cells forming monolayer in culture mimicking an intestinal epithelial barrier. This study demonstrated that the toxicity of poly(isobutylcyanoacrylate) nanoparticles is highly cell line-dependent.

(Hydroxypropyl)methylcellulose Mediated Synthesis of Highly Porous Composite Scaffolds for Trabecular Bone Repair Applications

This article presents an (hydroxypropyl)methylcellulose (HPMC) mediated synthesis of highly porous scaffolds containing nanocrystalline hydroxyapatite (n-HAp) and chitosan (CS) as major inorganic and organic phases, respectively. A mixture of n-HAp, CS, and HPMC is homogenized and freeze-dried to yield n-HAp/CS/HPMC composite scaffolds closely emulating trabecular bone in density (0.02 g cm-3) and porosity (89%). SEM images substantiate the porous structure of the scaffolds (pore size: 100-300 μm). The mechanical analysis reveal excellent compressive strength of the porous n-HAp/CS/HPMC scaffold (9.65 MPa) that is also comparable with human trabecular bone. The in vitro bioactivity and degradability of the porous scaffolds are investigated in tris-HCl-buffered synthetic body fluid (SBF) and phosphate buffer solution (PBS), respectively. The results indicate a rapid increase in scaffold mass due to apatite-like deposition and good resorbability. The SEM images of SBF soaked samples demonstrate apatite-like deposition on the surface of scaffolds with Ca/P ratio of 1.63 after 7 days of soaking in SBF. These results suggest that porous n-HAp/CS/HPMC scaffolds, due to their structural similarity, mechanical and in vitro biological properties, can become useful alternatives for trabecular bone regeneration and repair. © 2015 by American Scientific Publishers.

Influence of molecular weight on structure and rheological properties of microcrystalline chitosan mixtures

In the present work, the atomic force microscopy (AFM) studies and rheological properties of aqueous solutions of microcrystalline chitosan (MCCh), polyacrylamide (PAM) and their mixtures at different weight ratios have been investigated. Flow measurements were carried out using on solutions of native polymers and their mixtures with various weight fractions of components. It has been observed that the polymer solutions and their mixtures exhibited the non-Newtonian behavior with shear-thinning and/or shear-thickening areas. Rheological parameters from power law and activation energy of viscous flow are determined and discussed. The AFM images showed difference in surface properties films for the native polymers and their mixtures. The roughness of the mixtures increases with the increase of MCCh content. This may indicate a strong interaction between the polymeric components.