Role Of Chitosan Research Articles

Biocomposite scaffolds for bone regeneration: Role of chitosan and hydroxyapatite within poly-3-hydroxybutyrate-co-3-hydroxyvalerate on mechanical properties and in vitro evaluation

Bio-engineered scaffolds for bone tissue regeneration is an exploding area of research mainly because they can satisfy the essential demands and current challenges in bone replacement therapies, by imitating the extracellular matrix (ECM) of the native bone. We fabricated bio-composite nanofibrous scaffolds with a blend of poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV), chitosan (CTS) and hydroxyapatite (HA) during this study. Morphological evaluation confirmed the fiber diameters of PHBV, PHBV/CTS (90:10), PHBV/CTS/HA4 (85.5:9.5:5) and PHBV/CTS/HA8 (81:9:10) as 405±74nm, 334±82nm, 316±103nm and 256±110nm, respectively. The PHBV/CTS/HA4 and PHBV/CTS/HA8 scaffolds were capable of enduring the long term culture of human fetal osteoblasts (hFOB) with ultimate tensile strength of 3.55±0.22MPa and 4.19±0.19MPa, respectively. The proliferation of osteoblasts on PHBV/CTS/HA8 scaffold was found 34.10% higher than that on PHBV scaffold on day 20. Cell maturation identified by alkaline phosphatase activity on day 20 was significantly higher on PHBV/CTS/HA8 scaffold than that on PHBV scaffold. The cells on PHBV/CTS/HA8 scaffold also acquired higher mineral deposition (25.79%) than the mineral deposition on PHBV scaffold by day 20, confirmed by EDX analysis. Based on the results, we concluded that the electrospun PHBV/CTS/HA8 scaffolds hold great potential to promote the regeneration of bone tissue due to the synergistic effect of chitosan and HA, whereby chitosan provided cell recognition sites while HA acted as a chelating agent for organizing the apatite-like mineralization.

The Role of Chitosan in Treatment Interstitial Cystitis

The Role of Chitosan in Treatment Interstitial Cystitis

A Short Review on Chitosan Membrane for Biomolecules Immobilization

Chitosan is an important natural polymer that occurs in the world. Chitosan is soluble in acidic aqueous media and it can be obtained in various forms. It is widely used for many applications. Hence, we briefly describe the role of chitosan in membrane form, an important area of research in which a variety of synthetic methods has been proposed and their significance is explained. Thus, this review emphasizes the papers on the high value-added applications of these chitosan membranes in diverse fields such as medicine, biological, cosmetics and nanotechnology.

Role of Chitosan on Some Physical Properties and the Urea Controlled Release of the Silk Fibroin/Gelatin Hydrogel

Natural polymers are widely used as biodegradable matrices for the controlled release technology because they can improve the performance of the materials and make them environmentally friendly. In this work, the silk fibroin (SF)/gelatin hydrogel with chitosan (CS) was prepared by solvent casting aiming to reduce the rate of urea release from the hydrogels. Results from the Fourier transform infrared confirmed that no intermolecular interactions had taken place after the addition of CS into the SF/gelatin. Furthermore, the increase of CS content in the SF/gelatin blended hydrogels caused the decrease in their porosity that affected the increase in their crystallinity, degree of swelling, water solubility, and surface hydrophobicity. The rate of urea release from the hydrogels also depended on the content of CS of which its value of diffusion exponent characteristics (n) determined from the Korsmeyer-Peppas model for SF/gelatin/CS hydrogels were greater than 1.0. This indicated that the urea release from the SF/gelatin hydrogels with CS was a super case II transport type. Moreover, the urea release rate (k) of the SF/gelatin/CS hydrogels was lower than that of the SF/gelatin hydrogel itself indicating an extension of the urea release from the SF/gelatin hydrogels by CS which could be utilized for controlled release applications.

Nutraceuticals in lipid-lowering treatment: a narrative review on the role of chitosan.

Lipid-lowering drugs may cause adverse effects and, although lipid targets may be achieved, a substantial residual cardiovascular (CV) risk remains. Treatment with agents mimicking proteins present in the body, such as incretin-based therapies, provided promising results. However, in order to improve lipids and CV risk, lifestyle measures remain important. Some researchers focused on nutraceuticals that may beneficially affect metabolic parameters and minimize CV risk. Chitosan, a dietary fiber, can regulate lipids with benefit on anthropometric parameters. The beneficial properties of dietary supplements (such as green tea extract, prebiotics, plant sterols, and stanols) on plasma lipids, lipoproteins, blood pressure, glucose, and insulin levels and their anti-inflammatory and anti-oxidant effects are documented. However, larger, prospective clinical trials are required to confirm such benefits. Such treatments may be recommended when lipid-lowering drugs are neither indicated nor tolerated as well as in order to achieve therapeutic targets and/or overcome residual CV risk.

Theranostics: A Way of Modern Medical Diagnostics and the Role of Chitosan

The concept of therapeutic and diagnostic activities is mainly concerned to medical and pharmaceutical sciences. However, the recent trends earmarked the synergistic approaches of science and technology to provide more vibrant and effective medical treatment for the solution of health complications in medical sciences and it’s the genesis of modern medical diagnostic. Hence, medical research is directed towards most promising and challenging fields of therapeutics + diagnostics = theranostics. The feasibility of theranostics nowadays is apprehended in various disease diagnostics and curing processes. The modern medical diagnostic techniques are based on molecular imaging where each technique has its own characteristics, merits and demerits and most of the imaging modalities are complementary to each other. To provide better results of imaging the theranostic agents play very important role. The useful biopolymer research has been assisted towards the evolution of improved imaging agents in the form of quantum dots, nanoparticles and other new regenerative medication. The mini review focuses on theranostic development with special emphasis on quantum dots, and nanoparticles in the light of biopolymer, chitosan for cancer diseases.

Chitosan-induced defence responses in tomato plants against early blight disease caused by Alternaria solani (Ellis and Martin) Sorauer

The in vitro antifungal properties of chitosan and its role in protection of tomato from early blight disease were evaluated. Chitosan inhibited the radial and submerged growth of Alternaria solani at 1 mg/ml, and controls tomato plants from blight pathogen. Chitosan induces the level of chitinase activity and new isoforms of chitinase resulting in the reduction of early blight disease severity in tomato leaves. These results suggested the role of chitosan in activation of defence responses as well as protecting tomato plants from A. solani infection.

The Role of Chitosan in Emulsion Formation and Stabilization

This article reviews the basic principles of emulsion formation and stabilization through the electrosteric function of chitosan. Chitosan, which is a polycationic biopolymer, may act as an emulsifier and emulsion stabilizer through adsorption of the protective layer at oil-water interfaces, viscosity enhancement, and interaction with surface-active agents (e.g., surfactants, proteins, and polysaccharides). The interaction of chitosan at droplet interfaces can be associated with flocculation or electrosteric stabilization, depending on the nature and concentration of the chitosan, emulsifier characteristics, and the pH and ionic strength of solution.

Recovery of Zero-Valent Ruthenium from Acetic Acid Waste Solution by a Combined Process of Biosorption with Bacterial Biosorbent Fibers and Incineration

This study introduces a new process for the recovery of zero-valent ruthenium (Ru) from acetic acid waste solution by a combined process of biosorption with bacterial biosorbent fibers and incineration. As an effective sorbent to bind Ru-acetate complexes, polyethylenimine (PEI)-modified bacterial biosorbent fibers (PBBF) were developed and used for the experiments. The PBBF were prepared by extruding the blended mixture of chitosan-Corynebacterium glutamicum biomass as a fiber, coating the fiber with PEI and cross-linked using glutaraldehyde, consecutively. The role of chitosan in the bacterial biosorbent fiber was binder of the biomass. Batch biosorption studies showed that the maximum Ru uptakes of raw biomass and PBBF were estimated to be 16.0 and 110.5 mg/g, respectively. Kinetic studies showed that PBBF was as fast as powder form of raw biomass. After biosorption, the Ru-acetate complexes ions sorbed biosorbents were incinerated for recover Ru as a metallic form. These biosorbent constituents could be burnt out and at the same time, the sorbed Ru-acetate complexes ions could be reduced to Ru0. X-ray photoelectron spectroscopy (XPS) results indicated that the Ru-acetate complexes ions were able to be reduced into metallic form of zero-valent Ru. X-ray fluorescence spectrometry (XRF) was applied for analysis of impurity metals in the recovered Ru containing ashes. The purity of metallic Ru by means of XRF was 99.79%. The proposed sequential process of biosorption and incineration for recovery of Ru from acetic acid waste solution would contribute to the solution of several problems such as the Ru recovery efficiency, generation of secondary waste, and recover costs and energy.

The role of chitosan as nanofiller of graphite oxide for the removal of toxic mercury ions

The present study focuses on the role of chitosan (CS) as nanofiller of graphite oxide (GO) in order to prepare composite materials with improved Hg(II) adsorption properties. The removal of Hg(II) from aqueous solutions was studied using adsorbents as graphite oxide (GO), graphite oxide nanofilled with chitosan (GO/CS) and magnetic chitosan (GO/mCS). Many possible interactions between materials and Hg(II) were observed after adsorption and explained via characterization with various techniques (SEM/EDAX, FTIR, XRD, DTG). The adsorption evaluation was done studying various parameters as the effect of pH (both in adsorption and desorption), contact time (pseudo-second order fitting), temperature (isotherms at 25, 45, 65°C), in line with a brief thermodynamic analysis (ΔG0, ΔH0, ΔS0). The maximum adsorption capacity (fitting with Langmuir model) of GO at 25°C was Qmax=187mg/g, while after the CS nanofilling (formation of the composite GO/CS), Qmax was increased to 381mg/g with a further enhancement for GO/mCS (Qmax=397mg/g).

Theoretical Study of Hydrogen Bond Formation in Chitosan and Pentagonal Dodecahedron Methane Hydrate Cage Structure

Density functional theory based calculations have been performed to study hydrogen bond formation between pentagonal dodecahedron methane hydrate cage and chitosan. The role of chitosan as a potential methane hydrate inhibitor is elucidated, based on electronic structure property correlations. Geometry optimization, frontier orbitals and natural bond orbital (NBO) analysis of methane hydrate pentagonal dodecahedron cage with and without the presence of chitosan molecule using B3LYP DFT-D/6-31++G(d,p) have been performed. Calculated interaction energies, geometrical parameters and NBO analysis reveal that chitosan has strong potential to hinder the formation of pentagonal dodecahedron methane hydrate cage.

Antibacterial activity of two chitosan solutions and their effect on rice bacterial leaf blight and leaf streak

Bacterial leaf blight and leaf streak are the two most damaging bacterial diseases of rice. However, few bactericidal chemicals are available for controlling both diseases. The antibacterial properties of two kinds of chitosan with different molecular weights and degrees of N-deacetylation and their effect on rice bacterial leaf blight and leaf streak were evaluated. Results showed that the two kinds of chitosan solution possess a strong antibacterial activity against both rice bacterial pathogens and significantly reduced disease incidence and severity by comparison with the control under greenhouse conditions. However, the interaction between chitosan and rice pathogens was affected by the type and concentration of chitosan, the bacterial species and the contact time between chitosan and bacteria. The direct antibacterial activity of chitosan may be attributed to both membrane lysis and the destruction of biofilm. In addition, both chitosan solutions significantly increased the activities of phenylalanine ammonia lyase, peroxidase and polyphenol oxidase in rice seedlings following inoculation of two rice pathogens by comparison with the control. The role of chitosan in protection of rice against bacterial pathogens has been shown to involve direct antibacterial activity and indirect induced resistance.

The role of chitosan as a mucoadhesive agent in mucosal drug delivery

Mucoadhesive properties of chitosan are supported by an exceedingly high number of papers and have been studied using a number of different methods. Also, the myriad of chitosan derivatives that have been synthesized and proposed for pharmaceutical use have been studied for mucoadhesion, looking at the changes in mucoadhesivity induced by structure modifications. The review will briefly recall the possible mechanisms involved in chitosan mucoadhesivity, among which ionic interactions with mucin chains and hydration state are the prevailing ones. Furthermore, adhesion mechanism inevitably depends on the environmental conditions as well as on the type of physical and pharmaceutical form considered. Therefore, the testing methods used for mucoadhesivity should be carefully chosen. The present review will report on the experience acquired by the authors in the field. The focus will be on some examples of liquid, semisolid, solid and nanoparticulate formulations based on either chitosan or chitosan derivatives and on how it is possible to choose the most suitable testing method depending on the envisaged mucoadhesion mechanism and on the physical/pharmaceutical form under examination.

Scaffolds Based Bone Tissue Engineering: The Role of Chitosan

As life expectancy increases, malfunction or loss of tissue caused by injury or disease leads to reduced quality of life in many patients at significant socioeconomic cost. Even though major progress has been made in the field of bone tissue engineering, present therapies, such as bone grafts, still have limitations. Current research on biodegradable polymers is emerging, combining these structures with osteogenic cells, as an alternative to autologous bone grafts. Different types of biodegradable materials have been proposed for the preparation of three-dimensional porous scaffolds for bone tissue engineering. Among them, natural polymers are one of the most attractive options, mainly due to their similarities with extracellular matrix, chemical versatility, good biological performance, and inherent cellular interactions. In this review, special attention is given to chitosan as a biomaterial for bone tissue engineering applications. An extensive literature survey was performed on the preparation of chitosan scaffolds and their in vitro biological performance as well as their potential to facilitate in vivo bone regeneration. The present review also aims to offer the reader a general overview of all components needed to engineer new bone tissue. It gives a brief background on bone biology, followed by an explanation of all components in bone tissue engineering, as well as describing different tissue engineering strategies. Moreover, also discussed are the typical models used to evaluate in vitro functionality of a tissue-engineered construct and in vivo models to assess the potential to regenerate bone tissue are discussed.

Preparation and evaluation of zinc–pectin–chitosan composite particles for drug delivery to the colon: Role of chitosan in modifying in vitro and in vivo drug release

Zinc–pectin–chitosan composite microparticles were designed and developed as colon-specific carrier. Resveratrol was used as model drug due to its potential activity on colon diseases. Formulations were produced by varying different formulation parameters (cross-linking pH, chitosan concentration, cross-linking time, molecular weight of chitosan, and drug concentration). Single-step formulation technique was compared with multi-step technique. Effect of these parameters was investigated on shape, size, weight, weight loss (WL), moisture content (MC), encapsulation efficiency (EE), drug loading (L), and drug release pattern of the microparticles. The formulation conditions were optimized from the drug release study. In vivo pharmacokinetics of the zinc-pectinate particles was compared with the zinc–pectin–chitosan composite particles in rats. Formulations were spherical with 920.48–1107.56 μm size, 21.19–24.27 mg weight of 50 particles, 89.83–94.34% WL, 8.31–13.25% MC, 96.95–98.85% EE, and 17.82–48.31% L. Formulation parameters showed significant influence on drug release pattern from the formulations. Formulation prepared at pH 1.5, 1% chitosan, 120 min cross-linking time, and pectin:drug at 3:1 ratio demonstrated colon-specific drug release. Microparticles were stable at 4 °C and room temperature. Pharmacokinetic study indicated in vivo colon-specific drug release from the zinc–pectin–chitosan composite particles only.

Lipid multilayered particles: the role of chitosan on structure and morphology

Multilayered nanovectors made up from a controlled binary lipid mixture (POPC and DMPS) and trimethyl chitosan (TMC) have been prepared and characterized by light- and small angle neutron scattering. The morphology and the multilayer structure of the particle outer shell has been described in detail. By varying the amount of TMC in the starting solution it is possible to tune the overall surface particle charge as well as its multilamellarity. In this way the drug loading/release properties of the particles can be controlled. Therefore the use of controlled POPC/DMPS mixtures can be a valid alternative to commercial lecithin to obtain nanovectors with specific release properties.

Flexibility and drug release features of lipid/saccharide nanoparticles

The effect of lipophilic additives (excipients and drugs) on the behavior of lipid/saccharide nanoparticles has been investigated by incoherent elastic neutron scattering. Temperature scans from 20 K to 350 K have been performed on lecithin/chitosan particles loaded with isopropyl myristate and cetyl-stearyl alcohol, two lipophilic molecules with different melting temperatures which are commonly added to improve drug loading efficiency. In a similar way the effect of tamoxifen citrate, a lipophilic drug frequently used in breast cancer therapy, has also been studied. The different melting points of the two excipients affect mostly the low-temperature behavior of the nanoparticles. At physiological temperatures they both improve the particle flexibility. On the other hand addition of tamoxifen leads to stiffer structures and to lower amounts of released drug. The macroscopic features of the drug release appear to be correlated to the microscopic flexibility determined by neutron scattering. The data confirm also the role of chitosan as a stiffening and stabilizing agent of the lipid particles.

Chitosan reinforced apatite–wollastonite coating by electrophoretic deposition on titanium implants

A novel bioactive porous apatite-wollastonite/chitosan composite coating was prepared by electrophoretic deposition. The influence of synthesis parameters like pH of suspension and current density was studied and optimized. X-ray diffraction confirmed crystalline phase of apatite-wollastonite in powder as well as composite coating with coat crystallinity of 65%. Scanning electron microscope showed that the porosity had interconnections with good homogeneity between the phases. The addition of chitosan increased the adhesive strength of the composite coating. Young's modulus of the coating was found to be 9.23 GPa. One of our key findings was sheet-like apatite growth unlike ball-like growth found in bioceramics. Role of chitosan was studied in apatite growth mechanism in simulated body fluid. In presence of chitosan, dense negatively charged surface with homogenous nucleation was the primary factor for sheet-like evolution of apatite layer. The results suggest that incorporation of chitosan with apatite-wollastonite in composite coating could provide excellent in vitro bioactivity with enhanced mechanical properties.

Simultaneous enhancement of the strength and elongation of polycaprolactone: The role of chitosan‐graft‐polycaprolactone

AbstractPolycaprolactone (PCL) is a basic substance for biomedical materials and especially for scaffolds in tissue engineering. To improve the performance of PCL‐based materials, we filled a PCL matrix with a biocompatible polysaccharide‐grafted PCL, chitosan‐g‐polycaprolactone (CS‐g‐PCL). The results showed that the strength, elongation, and Young's modulus of the resultant composites were simultaneously enhanced in contrast with those of neat PCL. The structures of the PCL/CS‐g‐PCL blends were investigated with Fourier transform infrared, X‐ray diffraction, differential scanning calorimetry, dynamic mechanical analysis, and scanning electron microscopy, and the effects of the chitosan (CS) content in CS‐g‐PCL and the CS‐g‐PCL content in the blends on the mechanical properties and structures of the blends were examined. The rigidity of CS chains and the increasing crystallinity induced by the nucleation of CS‐g‐PCL contributed to the enhancement of the strength, whereas the cocontinuous interfacial structure and improved miscibility between CS and PCL matrix mediated with grafted PCL chains greatly enhanced the elongation of the composite materials. This work presents a strategy for enhancing the mechanical performance of PCL as a biomaterial. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Influence of Piperine on Transcutaneous Permeation of Repaglinide in Rats and on Tight Junction Proteins in HaCaT Cells: Unveiling the Mechanisms for Enhanced Permeation

The purpose of this study was to evaluate the influence of piperine on permeation of repaglinide (RGE) across rat epidermis. In addition, the role of chitosan (CTN) and its combination with piperine was investigated for exploring the possibility of further enhancing the permeation of RGE. The permeation of RGE across excised rat epidermis was, respectively, ~4-fold, ~5-fold and ~6- fold higher when piperine (0.008% w/v), CTN (1% w/v), or piperine – CTN mixture was used as donor vehicle as compared to propylene glycol: ethanol (PG: EtOH) (7:3) mixture. The merger of T2 and T3 (lipid-specific) and obliteration of T4 (protein-specific) endothermic transitions in the thermograms of excised rat epidermis suggested overwhelming influence of these treatments on skin lipids and proteins. Further, the observed increase in intercellular space, disordering of lipid structure and corneocyte detachment indicated considerable effect on the ultrastructure of rat epidermis. The enhancement in permeation of RGE across rat epidermis excised after various treatments for different periods was correlated with the transepidermal water loss of similarly treated viable rat skin. The treatment of HaCaT cell line with piperine influenced the TJ plaque protein zonula occludens (ZO-1) as evidenced by reduced immunofluorescence of anti-TJP1 (ZO-1) antibody in confocal laser scanning microscopic studies. Treatment of HaCaT cells with CTN decreased the intensity of fluorescence on the cell walls only marginally. However, remarkable decrease in the immunofluorescence of anti-TJP1 (ZO-1) antibody was observed after treatment of HaCaT cells with mixture of piperine and CTN. The systemic delivery of RGE in rats was enhanced by 8-fold and 9.5-fold from transdermal formulations containing, respectively, piperine (0.008 % w/v) or piperine (0.008 % w/v)–CTN (1% w/v) mixture as enhancer. Overall, the observations suggested overwhelming influence of piperine and CTN on ZO-1 protein to be responsible for enhancing the percutaneous permeation of RGE.