Chitosan Poly Research Articles

Chitosan Poly(vinyl alcohol) Methacrylate Hydrogels for Tissue Engineering Scaffolds.

A major challenge in tissue engineering scaffolds is controlling scaffold degradation rates during healing while maintaining mechanical properties to support tissue formation. Hydrogels are three-dimensional matrices that are widely applied as tissue scaffolds based on their unique properties that can mimic the extracellular matrix. In this study, we develop a hybrid natural/synthetic hydrogel platform to tune the properties for tissue engineering scaffold applications. We modified chitosan and poly(vinyl alcohol) (PVA) with photo-cross-linkable methacrylate functional groups and then synthesized a library of chitosan PVA methacrylate hydrogels (ChiPVAMA) with two different photoinitiators, Irgacure 2959 (I2959) and lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP). ChiPVAMA hydrogels showed tunability in degradation rates and mechanical properties based on both the polymer content and photoinitiator type. This tunability could enable their application in a range of tissue scaffold applications. In a 2D scratch wound healing assay, all hydrogel samples induced faster wound closure compared to a gauze clinical wound dressing control. NIH/3T3 cells encapsulated in hydrogels showed a high viability (∼92%) over 14 days, demonstrating the capacity of this system as a supportive cell scaffold. In addition, hydrogels containing a higher chitosan content demonstrated a high antibacterial capacity. Overall, ChiPVAMA hydrogels provide a potential tissue engineering scaffold that is tunable, degradable, and suitable for cell growth.

Zinc Oxide–Incorporated Chitosan–Poly(methacrylic Acid) Polyelectrolyte Complex as a Wound Healing Material

A novel type of porous films based on the ZnO-incorporated chitosan-poly(methacrylic acid) polyelectrolyte complex was developed as a wound healing material. The structure of porous films was established by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and energy dispersive X-ray (EDX) analysis. Scanning electron microscope (SEM) and porosity studies revealed that the pore size and porosity of the developed films increased with the increase in zinc oxide (ZnO) concentration. The porous films with maximum ZnO content exhibited improved water swelling degree (1400%), controlled biodegradation (12%) for 28 days, a porosity of 64%, and a tensile strength of 0.47 MPa. Moreover, these films presented antibacterial activity toward Staphylococcus aureus and Micrococcus sp. due to the existence of ZnO particles. Cytotoxicity studies demonstrated that the developed films had no cytotoxicity against the mouse mesenchymal stem (C3H10T1/2) cell line. These results reveal that ZnO-incorporated chitosan-poly(methacrylic acid) films could be used as an ideal material for wound healing application.

Chitosan–poly(vinyl alcohol)–ionic liquid-grafted hydrogel for treating wastewater

A chitosan–poly(vinyl alcohol)–ionic liquid-grafted hydrogel for wastewater treatment is described.

Chitosan–poly(acrylamide-co-maleic acid) composite synthesis, characterization, and investigation of protein adsorption behavior

Chitosan–poly(acrylamide-co-maleic acid) composite synthesis, characterization, and investigation of protein adsorption behavior

Effect of Chitosan-Poly(Acrylic Acid) Complexes and Two Nutrient Solutions on the Growth and Yield of Two Habanero Pepper Cultivars

Chitosan (CS) is a natural polymer used in agriculture as a biostimulant that has been evaluated in different plant models. In this study, we evaluated the effect of the foliar application of chitosan–poly(acrylic acid) complexes (CS–PAA) and two nutrient solutions (A and B) on the parameters of growth and yield of two habanero pepper cultivars (Chichen Itza and Jaguar) in a greenhouse. Over the course of the experiment, eight foliar applications were carried out at 15-day intervals. Our results showed that foliar applications of CS–PAA complexes have a biostimulant effect on the habanero pepper crop by increasing the total dry biomass of the plant and the number of fruits of the two cultivars. Regarding nutrient solutions, the nutrient solution A increased the yield of the Chichen Itza cultivar; this effect was because it had a better balance of potassium and calcium compared to the nutrient solution B. These results provide advances on the use of CS–PAA complexes as a biostimulant and the management of nutrient solutions in the crop of habanero peppers.

Positively Charged Quaternized Chitosan Poly(Vinylidene Fluoride) Membrane for Selective Separation of Negatively Charged Polysaccharides –Exemplified with Heparin

Positively Charged Quaternized Chitosan Poly(Vinylidene Fluoride) Membrane for Selective Separation of Negatively Charged Polysaccharides –Exemplified with Heparin

Mannose-Modified Chitosan Poly(lactic-co-glycolic acid) Microspheres Act as a Mannose Receptor-Mediated Delivery System Enhancing the Immune Response.

The mannose receptor (MAN-R)-targeted delivery system is commonly used to deliver antigens to macrophages or immature dendritic cells (DCs) to promote the efficiency of antigen presentation. To maximize the enhancement effects of chitosan (CS) and induce an efficient humoral and cellular immune response against an antigen, we encapsulated ovalbumin (OVA) in poly(lactic-co-glycolic acid) (PLGA) microspheres (MPs) and conjugated it with MAN-modified CS to obtain MAN-R-targeting nano-MPs (MAN-CS-OVA-PLGA-MPs). The physicochemical properties, drug loading rate, and immunomodulation activity of MAN-CS-OVA-PLGA-MPs were evaluated. In vitro, MAN-CS-OVA-PLGA-MPs (80 μg mL−1) could enhance the proliferation of DCs and increase their phagocytic efficiency. In vivo, MAN-CS-OVA-PLGA-MPs significantly increased the ratio of CD3+CD4+/CD3+CD8+ T cells, increased CD80+, CD86+, and MHC II expression in DCs, and improved OVA-specific IgG, IgG1, IgG2a, and IgG2b antibodies. Moreover, MAN-CS-OVA-PLGA-MPs promoted cytokine (IFN-γ, IL-4, and IL-6) production in mice. Taken together, our results show that MAN-CS-OVA-PLGA-MPs may act by activating the T cells to initiate an immune response by promoting the maturation of dendritic cells and improving their antigen presentation efficiency. The current study provides a basis for the use of MAN-CS-OVA-PLGA-MPs as an antigen and adjuvant delivery system targeting the MAN-R on the surface of macrophages and dendritic cells.

Physical-Chemical Crosslinked Electrospun Colocasia esculenta Tuber Protein-Chitosan-Poly(Ethylene Oxide) Nanofibers with Antibacterial Activity and Cytocompatibility.

BackgroundElectrospun nanofibers based on Colocasia esculenta tuber (CET) protein are considered as a promising material for wound dressing applications. However, the use of these nanofibers in aqueous conditions has poor stability. The present study was performed to obtain insights into the crosslinked electrospun CET’s protein–chitosan (CS)–poly(ethylene oxide) (PEO) nanofibers and to evaluate their potential for wound dressing applications.MethodsThe electrospun nanofibers were crosslinked with glutaraldehyde (GA) vapor and heat treatment (HT) to enhance their physicochemical stability. The crosslinked nanofibers were characterized by protein profiles, morphology structures, thermal behavior, mechanical properties, and degradation behavior. Furthermore, the antibacterial properties and cytocompatibility were analyzed by antibacterial assessment and cell proliferation.ResultsThe protein profiles of the electrospun CET’s protein–CS–PEO nanofibers before and after HT crosslinking contained one major bioactive protein with a molecular weight of 14.4 kDa. Scanning electron microscopy images of the crosslinked nanofibers indicated preservation of the structure after immersion in phosphate buffered saline. The crosslinked nanofibers resulted in higher ultimate tensile strength and lower ultimate strain compared to the non-crosslinked nanofibers. GA vapor crosslinking showed higher water stability compared to HT crosslinking. The in vitro antibacterial activity of the crosslinked nanofibers showed a stronger bacteriostatic effect on Staphylococcus aureus than on Escherichia coli. Human skin fibroblast cell proliferation on crosslinked GA vapor and HT nanofibers with 1% (w/v) CS and 2% (w/v) CET’s protein demonstrated the highest among all the other crosslinked nanofibers after seven days of cell culture. Cell proliferation and cell morphology results revealed that introducing higher CET’s protein concentration on crosslinked nanofibers could increase cell proliferation of the crosslinked nanofibers.ConclusionThese results are promising for the potential use of the crosslinked electrospun CET’s protein–CS–PEO nanofibers as bioactive wound dressing materials.

Effect of Technogenic Factors and Biodestructive Agents on the Thermal Behavior of Chitosan and Poly(methyl acrylate) Block Copolymer

Thermal analysis of samples of chitosan–poly(methyl acrylate) block copolymer after exposure to electromagnetic fields, ultraviolet radiation, ultrasound, and biodestructive agents is performed for the first time by means of differential scanning calorimetry in the range of 250–510 K and thermogravimetry in the region of 300–850 K. It is shown that the combined effect of physical factors and biodestructive agents alters certain physicochemical properties: the temperatures of physical transformations, the temperatures of the onset of thermal degradation, and the nature of thermal decomposition.

Neuroprotective effect of chitosan nanoparticle gene delivery system grafted with acteoside (ACT) in Parkinson’s disease models

Developing new drugs to treat Parkinson's disease efficiently is challenging. Here we report that chitosan nanoparticles (APPDNs) could serve as novel candidates for the design of anti-PD drugs. In this study, we investigated the effects of chitosan poly ethyleneglycol-poly lactic acid (PEG-PLA) nanoparticles conjugated with nerve growth factor (NGF), acteoside (ACT) and plasmid DNA (pDNA) for PD therapy using in vitro and in vivo models. Using PD cell models, we demonstrated that APPDN had good neuroprotective effects. More significantly, experiments using mouse PD models demonstrated that APPDNs could ameliorate the behavioral disorders of sick mice. Immunohistochemical and western blot (WB) analyses demonstrated that APPDNs could significantly reverse dopaminergic (DA) neuron loss in the substantia nigra and striatum of sick mice. This study opens up a novel avenue to develop anti-PD drugs.

Multichannel hydrogel based on a chitosan–poly(vinyl alcohol) composition for directed growth of animal cells

In this study, a new method for production of hydrogels with oriented multichannel structure based on chitosan–poly(vinyl alcohol) compositions was developed. Microscopic and biological studies of the obtained hydrogels were conducted to determine the optimal composition, which would ensure that structure of the material mimics that of the epineurium and perineurium in a nerve. Structure of the hydrogels was adjusted by variation of the initial concentration of the precipitant, poly(vinyl alcohol), and acid in the chitosan compositions. A single cycle of freezing and thawing of the produced hydrogels resulted in lower structural heterogeneity, which is promising for the production of a scaffold that simulates the structure of the native peripheral nerve. in vitro cytotoxic assays showed biocompatibility of the manufactured hydrogels.

Preparation of Chitosan Poly(methacrylate) Composites for Adsorption of Bromocresol Green.

In the present study, chitosan poly(methacrylate) composites were prepared and applied for adsorption of bromocresol green from aqueous solutions. The synthesized composites were characterized with scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The bromocresol green removal by the developed adsorbent was investigated, and the effects of experimental parameters, including sample pH and adsorption time, were also examined. Furthermore, the adsorption characteristics of the synthesized adsorbent, including kinetics, adsorption isotherms, and thermodynamics, were comprehensively studied. The adsorption isotherm was well described by the Freundlich model, and the maximum adsorption capacity was 39.84 μg mg–1 by shaking for 40 min at pH 2.0. Bromocresol green adsorption kinetics followed a pseudo-second-order kinetic model, indicating that adsorption was the rate-limiting step. Thermodynamic parameters and the negative values of Gibbs free energy change (ΔG°) showed that adsorption was a spontaneous process. The positive values of entropy change (ΔS°) implied that the adsorption of bromocresol green on chitosan poly(methacrylate) composites was an increasing random process. In addition, enthalpy change (ΔH°) values were positive, suggesting that the adsorption of bromocresol green was endothermic. The adsorption percentage of bromocresol green with chitosan poly(methacrylate) composites remained above 97% after three times of recycling test.

Local Dissipative Processes in Chitosan–Poly(vinyl alcohol) Composite System

Internal friction spectra in a chitosan–poly(vinyl alcohol) system have been recorded and analyzed in a wide temperature range using the method of free damped torsional vibrations. A modulus defect characterizing the mechanical parameters of the system has been determined. It has been shown that the composite material in the form of film differing in the ratio of components represents a heterogeneous (disperse) system, with poly(vinyl alcohol) acting as a dispersion medium at the specific ratio of components. The presence of two glass transition peaks on the temperature dependence λ = f(Т) due to dissipative processes of individual components of the mixed film has been demonstrated.

Structural and optical properties of chitosan–poly(amidoamine) dendrimer composite thin film for potential sensing Pb2+ using an optical spectroscopy

Poly(amidoamine) and chitosan have received attention due to their potential for sensing application. Chitosan–poly(amidoamine) dendrimer composite (Cs–PAMAM) thin film have been prepared using a spin coating technique. The functional group of Cs–PAMAM has been investigated using Fourier transform infrared spectroscopy (FTIR). The UV–vis absorption of Cs–PAMAM thin film was high with the optical band gap of 4.09 eV. The studies of potential sensing of the Cs–PAMAM thin film gave positive responses towards Pb2+ ion by using surface plasmon resonance spectroscopy. The surface morphology of the Cs–PAMAM composite thin film was observed using atomic force microscopy (AFM) and confirmed the interaction of Pb2+.

Orally targeted galactosylated chitosan poly(lactic-co-glycolic acid) nanoparticles loaded with TNF-ɑ siRNA provide a novel strategy for the experimental treatment of ulcerative colitis

The current treatments used in inflammatory bowel disease (IBD) therapy have significant side effects. Thus, it is very necessary to position and release TNF-α siRNA in inflamed tissues. Here, we demonstrate that poly(lactic-co-glycolic acid) can pack TNF-α siRNA efficiently into nanoparticles (NPs), and galactosylated chitosan (GC) can be grafted onto the NP surface, improving the RAW 264.7 macrophage-targeting kinetics of the NPs in vitro. Next, we orally administered GC-modified NPs loaded with TNF-α siRNA to C57BL/6 mice treated with 3% dextran sodium sulfate (DSS) to investigate their use in the treatment of colitis. When TNF-α siRNA loaded NPs were released into the colitis tissues of mice, GC-modified NPs (GPNs) alleviated the inflammation more efficiently than unmodified PGLA NPs (PNs). A series of colitis parameters (e.g., weight loss, myeloperoxidase (MPO) activity) demonstrated that GPNs have better anti-inflammatory effects than PNs. As indicated by flow cytometry, grafting GC onto NPs increased the macrophage uptake capacity and improved the kinetics of endocytosis. Collectively, our findings indicate that GC- modified TNF-α siRNA loaded NPs are powerful and efficient nanoscale materials for the delivery of therapeutic molecules to colitis tissues.

Chemotherapeutic Efficacy of Implantable Antineoplastic-Treatment Protocols in an Optimal Mouse Model for Human Ovarian Carcinoma Cell Targeting.

The present study aimed to design and develop a nanocomposite drug delivery system employing an antineoplastic-loaded antibody functionalized nanomicelle encapsulated within a Chitosan–Poly(vinylpyrrolidone)–Poly(N-isopropylacrylamide) (C–P–N) hydrogel to form an in situ forming implant (ISFI), responsive to temperature and pH for cancer cell-targeting following intraperitoneal implantation. The optimum nanomicelle formulation was surface-functionalized with anti-MUC 16 (antibody) for the targeted delivery of methotrexate to human ovarian carcinoma (NIH:OVCAR-5) cells in Athymic nude mice that expressed MUC16, as a preferential form of intraperitoneal ovarian cancer (OC) chemotherapy. The cross-linked interpenetrating C–P–N hydrogel was synthesized for the preparation of an in situ-forming implant (ISFI). Subsequently, the ISFI was fabricated by encapsulating a nanocomposite comprising of anti-MUC16 (antibody) functionalized methotrexate (MTX)-loaded poly(N-isopropylacrylamide)-b-poly(aspartic acid) (PNIPAAm-b-PASP) nanomicelles (AF(MTX)NM’s) within the cross-linked C–P–N hydrogel. This strategy enabled specificity and increased the residence time of the nanomicelles at tumor sites over a period exceeding one month, enhancing uptake of drugs and preventing recurrence and chemo-resistance. Chemotherapeutic efficacy was tested on the optimal ovarian tumor-bearing Athymic nude mouse model and the results demonstrated tumor regression including reduction in mouse weight and tumor size, as well as a significant (p < 0.05) reduction in mucin 16 levels in plasma and ascitic fluid, and improved survival of mice after treatment with the experimental anti-MUC16/CA125 antibody-bound nanotherapeutic implant drug delivery system (ISFI) (p < 0.05). The study also concluded that ISFI could potentially be considered an important immuno-chemotherapeutic agent that could be employed in human clinical trials of advanced, and/or recurring, metastatic epithelial ovarian cancer (EOC). The development of this ISFI may circumvent the treatment flaws experienced with conventional systemic therapies, effectively manage recurrent disease and ultimately prolong disease-free intervals in ovarian cancer patients.

Poly (ɛ-caprolactone)-chitosan-poly (vinyl alcohol) nanofibrous scaffolds for skin excisional and burn wounds in a canine model.

Poly (ɛ-caprolactone)-chitosan-poly (vinyl alcohol) (PCL: Cs: PVA) nanofibrous blend scaffolds were known as useful materials for skin wound healing and would help the healing process about 50% faster at the final time point. From the previous studies by the authors, PCL: Cs: PVA (in 2: 1: 1.5 mass ratio) nanofibres showed high efficacy in healing on rat models. In this study, the scaffolds were examined in burn and excision wounds healing on dogs as bigger models. The scaffolds were applied on dorsum skin wounds (n = 5) then macroscopic and microscopic investigations were carried out to measure the wounds areas and to track healing rate, respectively. Macroscopic results showed good aspect healing effect of scaffolds compared with control wounds especially after 21 days post-operating for both cutting and burn wounds. Pathological studies showed that the healing rates of the wounds covered with PCL: Cs: PVA nanofibrous scaffolds were much rapid compared to untreated wounds in control group. The immunogenicity of the scaffolds in canine model was also investigated. The findings showed that nanofibrous blend scaffolds was not immunogenic in humoural immune responses. All these results indicated that PCL: Cs: PVA nanofibrous web could be considered as promising materials for wounds healings.

Preparation and characterization of chitosan–poly(vinyl alcohol)–neomycin sulfate films

The aim of our study was obtaining chitosan–poly(vinyl alcohol)–neomycin sulfate films (Cs–PVA–Ne) by using solvent casting technique and the characterization of the products. The films were analyzed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, thermogravimetry (TG and DTG), differential scanning calorimetry (DSC), contact angle (CA) measurements, mechanical, and antibacterial activity tests. FTIR and DSC analysis demonstrated that interaction between Cs, PVA, and Ne took place. Static water CA measurements showed an improvement in the hydrophilicity of the Cs–PVA–Ne films. Also, the drug-loaded films proved to have fairly good mechanical strength and significant effects against Staphylococcus aureus and Escherichia coli. The unloaded films show minimum bacterial inhibition (~ 10.00 mm) compared to drug-loaded films (~ 30.00 mm). The bacterial inhibition was higher in all the cases of S. aureus than E. coli. Furthermore, PVA was found to improve the films properties. Due to their physical–chemical and mechanical features and the excellent antibacterial properties, the obtained Cs–PVA–Ne films are suitable for their use as wound-dressing materials.

Electrospinning of flux‐enhanced chitosan–poly(lactic acid) nanofiber mats as a versatile platform for oil–water separation

ABSTRACTEnvironmentally friendly chitosan (CS)–poly(lactic acid) (PLA) nanofiber mats were designed and constructed by an electrospinning strategy. Studies on the wettability of the CS–PLA nanofiber mats showed that they possessed excellent hydrophobic and oleophilic properties in the pH range 1–12. A layered oil–water mixture was separated by CS–PLA nanofiber mats, and the oil flux of the mats collected by #10 stainless steel wire mesh (sample P‐10) was up to 511.36 L m−2 h−1, which was approximately 25 times higher than that of the mats collected by #0 stainless steel wire meshes (sample P‐N). The superior properties of the CS–PLA nanofiber mats may have been due to their tunable porous structure and fine flexibility. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45830.

Bis(2-chloroethyl) ether-1,3-bis[3-(Dimethylamino)propyl]urea copolymer -Chitosan–Poly(acrylamide-co-diallyldimethylammonium chloride) blends as membranes For Alkaline Anion-exchange Membranes

Solid, thin, and flexible energy storage devices are required to power flexible and wearable technologies which are rapidly growing in importance. One of the key components for solid-state energy storage is a polymer electrolyte which eliminates liquid electrolyte leakage and minimizes bulky packaging. An ideal polymer electrolyte for supercapacitors should exhibit the following properties: (a) high ionic conductivity; (b) a wide electrochemical stability window for maximum cell voltage; and (c) high environmental and temperature stability for device safety and long service life[1-3]. In this paper, the novel, low-cost alkaline anion-exchange membranes (CS/PDDA), made from Chitosan and poly(diallyldimethylammonium chloride) blends, are successfully synthesized by a combined thermal and chemical cross-linking technique. The hydroxide conductivity (OH-), water uptake, ion exchange capacity (IEC), thermal stability, oxidative stability and alkaline stability of CS/PDDA membranes are measured to evaluate their applicability in electrochemical capacitors. The effects of membrane composition on OH- conductivity are studied using AC impedance technique. It is found that by cross-linking modifications, the membranes exhibit high OH- conductivity of 0.0162S cm-1 is achieved at m (CS) : m (PDDA)=1:0.5. The CS/PDDA membranes as electrode materials for supercapacitor demonstrated a wide voltage window (1.5 V), and exhibit high specific capacitance of 27.6 mF cm-2 at 100 mV s-1.