Chitosan Polyvinylpyrrolidone Research Articles

Electrically conductive bioplastics based on chitosan, polyvinyl alcohol, polyvinyl pyrrolidone, and plant extract nanoparticles for detecting Rhizopus stolonifer on tomato fruit

AbstractThis work aimed to manufacture bioplastics with mechanical and electrical properties for monitoring the Rhizopus stolonifer growth in tomato fruit packaging. Bioplastics were based on chitosan/polyvinyl alcohol (Ch/PVA), chitosan/polyvinyl pyrrolidone (Ch/PVP), and nanoparticles (NPs) of plant extracts at 10% and 30% of concentrations. Bioplastics were exposed to tomato inoculated with R. stolonifer for 6 d at 25°C. Water vapor permeability (WVP), mechanical properties, FTIR, UV–vis, morphology, electrical resistance of bioplastics, and the NPs size were assessed. In bioplastics added with plant extracts, 1.5 times more WVP than in the control group (18–35 gs−1m−1Pa−1) were quantified. Ch/PVA bioplastic showed 51% more tensile strength, 44% more elongation at break, and 40% more Young's modulus than Ch/PVP, regardless of the plant extract. The electrical resistance in Ch/PVA bioplastics with 30% mushroom extract and 10% radish allowed the differentiation between inoculated (109–1010 Ω) and non‐inoculated tomatoes (1010–1011 Ω). The FTIR assay confirmed the presence of each compound used in the bioplastic, and UV–vis confirmed phenols at 300 nm. The NPs measured less than 50 nm. Only Ch/PVA with 30% mushroom and 10% radish can be useful to monitor fungi in tomatoes based on their electrical behavior.

Coupling solvent extraction with pervaporation for efficient separation of lycopene from tomato waste using chitosan/polyvinylpyrrolidone (CS/PVP) pervaporative membranes and its optimization study

Coupling solvent extraction with pervaporation for efficient separation of lycopene from tomato waste using chitosan/polyvinylpyrrolidone (CS/PVP) pervaporative membranes and its optimization study

Study of the photoluminescence, optical, thermal, and electrical parameters of the Cs/PVP blend/zinc oxide nanorods films for energy storage devices

In this research, well-crystallized zinc oxide nanorods (ZnO NRs) were produced via a solid-state synthesis. Then, employing the casting method, doped chitosan/polyvinyl pyrrolidone (Cs/PVP) blended polymers with different concentrations of ZnO NRs were created. The wurtzite structure of ZnO was determined using XRD. The sample became increasingly amorphous up to a content of 1.5 wt% ZnO NRs, as shown by the XRD examination. TEM measurements of the ZnO nanorods show that their lengths range from 200 to 300 nm and their diameters are between 40 and 80 nm. FTIR analysis has been used to study the relationship between the polymer blend and ZnO NRs. The absorbance, transmittance, and reflectance spectra obtained from the diffused reflectance technique were utilized to study optical characteristics. With the addition of ZnO NRs to the polymer matrix, the optical band-gap narrows while the Urbach energy (tail bandwidth), extinction coefficient, refractive index, and optical conductivity increase. A photoemission peak at about 470 nm was visible in the PL spectra of films made of polymer nanocomposites. At normal temperature, polymer nanocomposites containing 1.5 wt% ZnO NRs had a greater ionic conductivity of 4.2 × 10−5 Scm−1. Studies on electric modulus and dielectric permittivity have also been conducted in order to comprehend the conductivity relaxation and charge storage characteristics. The Cs/PVP-ZnO nanocomposite is more suitable for use in thin-film solar cell applications and energy storage device applications because the decrease in band gap energy and values of the PL were typically accompanied by an increase in the dielectric and conductivity.

Incorporation of mixed-dimensional palygorskite clay into chitosan/polyvinylpyrrolidone nanocomposite films for enhancing hemostatic activity

Clay mineral-based hemostatic materials have attracted much attention in recent years, but it is scarce to report the hemostatic nanocomposite films containing natural mixed-dimensional clay composed of natural one-dimensional and two-dimensional clay minerals. In this study, the high-performance hemostatic nanocomposite films were facilely prepared by incorporating the natural mixed-dimensional palygorskite clay leached by oxalic acid (O-MDPal) into chitosan/polyvinylpyrrolidone (CS/PVP) matrix. By contrast, the obtained nanocomposite films exhibited the higher tensile strength (27.92 MPa), lower water contact angel (75.40°), better degradation, thermal stability and biocompatibility after incorporation of 20 wt% of O-MDPal, suggesting that O-MDPal contributed to enhancing the mechanical performance and water holding capacity of the CS/PVP nanocomposite films. Compared with the medical gauze and CS/PVP matrix groups, the nanocomposite films also indicated excellent hemostatic performance evaluated by blood loss and hemostasis time indexes based on the mouse tail amputation model, which might be ascribed to the enriched hemostatic functional sites, and hydrophilic surface, robust physical barrier role of nanocomposite films. Therefore, the nanocomposite film exhibited a promising practical application in wound healing.

Eco-Friendly Chitosan-Based Biodiesel Heterogeneous Catalyst Support Membrane

A chitosan-polyvinyl pyrrolidone K-30 (Cs-PVP.K30) membrane was prepared as a heterogeneous catalyst supporting membrane in the transesterification process in the production of biodiesel from palm oil and methanol through the blend reaction between chitosan (Cs) and polyvinyl pyrrolidone K-30 polymer (PVP K-30). Several membranes were characterized by their physicochemical and catalytic properties. Based on physicochemical data, it was found that including the carbonyl group from PVP K-30 into the chitosan framework correlated with an increase in porosity, hydrophilicity, water absorption, and the degree of swelling of the membrane. The results of the analysis using Fourier Transmittance Infra-red (FTIR) showed the spectra of carbonyl (-C=O) and hydroxyl (-OH) groups at wavenumbers 1648 cm-1 and 3363 cm-1, which shows that the reaction of chitosan alloy with PVP K-30 has been successfully carried out. The catalytic site of the Cs-PVP K30-NaOH membrane in the biodiesel production process was studied under several conversion conditions. It was found that the conversion of biodiesel reached 93.90% with a reaction time of 90 minutes, a temperature of 65°C, and an oil/methanol mole ratio of 1:7.

From Biowaste to Biomaterials: Buffalo Teeth Derived Hydroxyapatite Based Biocomposites for Bone Tissue Applications

The present study reported the preparation of food industry biowaste buffalo teeth-derived hydroxyapatite (BT-HA)/chitosan-polyvinyl pyrrolidone (CS-PVP)/aloe vera (ALV) natural biopolymer as a biocomposite for improved mechanical, antimicrobial and cytocompatible characteristics. The strengthening of biopolymer has a major role to play in improving the mechanical properties of the biocomposite, while the addition of aloe vera increases antimicrobial and cytocompatibility. Chemical structure, crystalline phase, morphology and mechanical property biocomposite were studied by FTIR, XRD, SEM-EDX and micro-hardness tests, respectively. Additionally, the antimicrobial effectiveness of the biocomposites was evaluated using Gram-positive and Gram-negative bacteria. The cytocompatibility of osteoblast cells to the biocomposites was calculated by the MTT assay examination. The findings demonstrated that the prepared biocomposite has the necessary mechanical, antimicrobial and biocompatible characteristics. Generally, the mixture of mechanical characteristics of CS-PVP, the antimicrobial and cytocompatible property of aloe vera in BT-HA/CS-PVP/ALV, makes the biocomposite a prospective restorative substance for various clinical applications.

Monitoring the infection process of Rhizopus stolonifer on strawberry fruit during storage using films based on chitosan/polyvinyl alcohol/polyvinylpyrrolidone and plant extracts

Different formulations based on nanoparticles of chitosan-plant extracts were evaluated to detect the infection process from the earliest stage of the fungus Rhizopus stolonifer on strawberry fruit during storage. Chitosan/polyvinyl alcohol (Ch/PVA) and chitosan/polyvinylpyrrolidone (Ch/PVP) films enriched with nanoparticles (NPs) of chitosan blended with plant extracts were prepared. They were placed inside a plastic package containing inoculated fruits and stored at 25 °C for 72 h. The thickness values of the films were in the range of 0.10 to 0.25 mm. All samples showed a maximum absorbance peak of about 300–320 nm; however, the Ch/PVP films enriched with NPs of chitosan and 10% of radish extract had an evident decrease in the optical absorbance as the fungal infection progressed. Additionally, as observed by scanning electron microscopy, the cross-section and surface morphology of films were not modified during storage, and the growth of R. stolonifer was evident after 48 h. Therefore, the Ch/PVP films enriched with chitosan NPs blended with 10% radish extract could be a reliable indicator of this fungus's growth.

An upgraded and universal strategy to reinforce chitosan/polyvinylpyrrolidone film by incorporating active silica nanorods derived from natural palygorskite

Active silica nanorod (OPal) was prepared from natural palygorskite (RPal) using an updated acid leaching route, and then the effect of RPal and OPal as nano-filler on the network structure, mechanical, thermal and anti-aging properties of chitosan/polyvinylpyrrolidone (CS/PVP) films was studied comparatively. It was revealed that OPal had a better dispersibility than RPal in CS/PVP substrate, and its incorporation improved the mechanical properties and thermal stability of the films significantly. The optimal composite film containing OPal shows the maximum tensile strength of 27.53 MPa (only 14.87 MPa and 22.47 MPa for CS/PVP and CS/PVP/RPal films, respectively), resulting from the more uniform dispersion of OPal in polymer substrate and its stronger interaction with 3D polymer network. By a controllable acid-leaching process, the metal ions in octahedral sheets of RPal were dissolved out continuously, which is favorable to alleviate the adverse effects of variable metal ions on the film under UV light irradiation, and thus improve the aging-resistant ability of films. This study provides new ideas for improving the reinforcing ability of natural clay minerals towards biopolymer-based material, finds a new way to resolve the aging problem of polymer composites caused by incorporation of natural clay minerals.

Development of cost effective metal oxide semiconductor based gas sensor over flexible chitosan/PVP blended polymeric substrate

In the present work, biodegradable and flexible chitosan/polyvinylpyrrolidone (CHP) polymeric substrate was fabricated by solvent casting method. This is a novel demonstration of the combination of natural polymer (chitosan) and synthetic polymer (PVP) for next-generation semiconductor device applications. The ZnO thin films were successfully synthesized on these polymeric substrates by facile drop-casting method for gas sensing applications. The hydrogen gas sensing properties of ZnO deposited on the polymeric substrate and SiO2 substrate show similar performance. The structural, morphological, optical, thermal, and tensile strength of the CHP substrate were studied using X-ray diffraction (XRD), Scanning electron microscopy (SEM), UV-visible spectroscopy, Derivative thermogravimetric analysis (DTG), and Universal testing machine (UTM), respectively. Our study suggests that the biodegradable CH/PVP flexible polymeric substrate provides a new way for the implementation of an eco-friendly green substrate in numerous electronic device applications.

Synthesis and characterization of chitosan–polyvinylpyrrolidone–bovine serum albumin-coated magnetic iron oxide nanoparticles as potential carrier for delivery of tamoxifen

The proposed study examined the preparation of chitosan (CS)–polyvinylpyrrolidone (PVP)–bovine serum albumin (BSA)-coated magnetic iron oxide (Fe3O4) nanoparticles (Fe3O4–CS–PVP–BSA) to use as potential drug delivery carriers for delivery of tamoxifen drug (TAM) . The anticancer drug selected in this study was tamoxifen which can be used for the human breast cancer treatment. These prepared nanoparticles were characterized by FTIR, XRD, SEM, AFM, TEM, CD and VSM techniques. The swelling studies have been measured at different (10, 20, 30, 40, 50%) drug loading. The mean particle size of the tamoxifen-loaded nanoparticles system (Fe3O4–CS–TAM, Fe3O4–CS–TAM–PVP and Fe3O4–CS–TAM–PVP–BSA) as measured by Malvern Zetasizer ranged between 350 ± 2.3 and 601 ± 1.7 nm. As well as these drug-loaded nanoparticles were positively charged. The zeta potential was in the range of 28.9 ± 3.5 and 50.8 ± 3.9 mV. The encapsulation efficiency was between 63.60 ± 2.11 and 96.45 ± 2.12%. Furthermore, in vitro release and drug loading efficiency from the nanoparticles were investigated. The cytotoxicity of prepared nanoparticles was verified by MTT assay. In vitro release studies were executed in 4.0 and 7.4 pH media to simulate the intestinal and gastric conditions and different temperature (37 and 42 °C). Hence, the prepared tamoxifen-loaded nanoparticles system (Fe3O4–CS–TAM, Fe3O4–CS–TAM–PVP and Fe3O4–CS–TAM–PVP–BSA) could be a promising candidate in cancer therapy.

Research on the preparation and characterization of chitosan grafted polyvinylpyrrolidone gel membrane with iodine

ABSTRACTThe chitosan grafted polyvinylpyrrolidone gel membrane with iodine (CS‐PVP‐I2‐G‐M) was prepared by chitosan–polyvinylpyrrolidone–iodine complex liquid (CS‐PVP‐I2‐L) mixed with gelatin. The intermediate product CS‐PVP‐I2‐L was prepared by CS grafted PVP in the protection of N2 with dimethyl 2,2′‐azobis (2‐methylpropionate) (AIBME) as initiator, then a certain amounts of iodine in ethanol solution was added. The properties of CS‐PVP‐I2‐G‐M were characterized by IR, UV–Vis, SEM, XRD, DSC, and so forth. The iodine release results coherent with the release kinetic model—Fick diffusion laws, has a burst effect first, and then spread, and the emission of iodine was maintained within a certain range and kept at a stable level permanently, showed a sustained‐release effect of iodine. The inhibition zone diameters of CS‐PVP‐I2‐G‐M against Staphylococcus aureus and Escherichia coli were both greater than 16 mm, it demonstrated significant antibacterial activity. Double effects sustained‐release effect of iodine and the significant antibacterial activity made CS‐PVP‐I2‐G‐M highly potential for applications as a novel natural biomedical sterilization materials. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41797.

Fabrication of porous chitosan-polyvinyl pyrrolidone scaffolds from a quaternary system via phase separation

Three-dimensional porous chitosan-polyvinyl pyrrolidone (PVP) scaffolds were fabricated for tissue engineering applications via liquid–liquid or liquid–solid phase separation. A mixture of an acidic aqueous solution with butanol as a non-solvent and a chitosan-PVP quaternary system were freeze-dried. We then studied the homogenous open pore structure and the minute pore distribution in order to improve the mass transfer and cell seeding efficiency while also obtaining the optimal ratio of PVP to provide high interconnectivity and to improve the open-pore structure. The properties of the porous chitosan-PVP scaffolds – including the microstructure, chemical release, water absorption properties, and cell proliferation tests were studied – and the results were compared against those obtained from conventional scaffolds. chitosan-PVP scaffolds with a porosity of over 70% were obtained, and the pore morphology on the surface and within the porous scaffolds showed the presence of homogenous open pores with excellent interconnectivity. As the PVP content increased, main pores (50–100 μm) and minute pores (4–10 μm) could be clearly observed. Also, the porous scaffold showed an improved efficiency for cell adhesion after the cells were cultured for 4 h. After 72 h, the cultured cells presented an increase in the cell proliferation and on the porous scaffolds. These results strongly suggest that the porous chitosan-PVP scaffolds can be widely used in tissue engineering, including for biopatches and artificial skin applications.

Lotus-leaf-like structured chitosan–polyvinyl pyrrolidone films as an anti-adhesion barrier

For postsurgical anti-adhesion barrier applications, lotus-leaf-like structured chitosan–PVP films were prepared using a solution casting method with dodecyltrichloro-immobilized SiO2 nanoparticles. We evaluated whether the lotus-leaf-like structured chitosan–PVP films (l-chitosan–PVP) could be applied as postsurgical anti-adhesion barriers. A recovery test using a tensile strength testing machine and measurement of crystallinity using X-ray diffraction indicated that films with 75% PVP were the optimal composition of the chitosan–PVP films. Also, dodecyltrichloro-immobilized SiO2 nanoparticles were synthesized and sprayed on the film after pretreatment with the instant bio-glue. Analysis of cell adhesion, proliferation, and anti-thrombus efficiency were performed via a WST assay, field emission scanning electron microscopy, and hemacytometry. The contact angle with the lotus-leaf-like surface was of approximately 150°. Furthermore, the l-chitosan–PVP film yielded a lower cell and platelet adhesion rate (around less than 4%) than that yielded by the untreated film. These results indicate that the lotus-leaf-like structure has a unique property and that this novel l-chitosan–PVP film can be applied as a blood/tissue-compatible, biodegradable material for implantable medical devices that need an anti-adhesion barrier.

Graphene oxide reinforced chitosan/polyvinylpyrrolidone polymer bio‐nanocomposites

ABSTRACTBio‐nanocomposite films based on chitosan/polyvinylpyrrolidone (CS/PVP) and graphene oxide (GO) were processed using the casting/evaporation technique. It has been found that the three components of bio‐nanocomposites can be easily mixed in controlled conditions enabling the formation of thick films with high quality, smooth surface and good flexibility. Structural and morphological characterizations showed that the GO sheets are well dispersed in the CS/PVP blend forming strong interfacial interactions that provide an enhanced load transfer between polymer chains and GO sheets thus improving their properties. It has been found that the water resistance of the CS/PVP blend is improved, and the hydrolytic degradation is limited by addition of 0.75 and 2 wt % GO. The modulus, strength, elongation and toughness of the bio‐nanocomposites are together increased. Herein, the steps to form new bio‐nanocomposite films have been described, taking the advantage of the combination of CS, PVP and GO to design the aforementioned bio‐nanocomposite films, which allow to have extraordinary properties that would have promising applications as eventual packaging materials. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41042.

Semi-IPN chitosan/polyvinylpyrrolidone microspheres and films: sustained release and property optimisation

A set of chitosan-polyvinylpyrrolidone (CH-PVP) microspheres were prepared as semi-inter penetrating networks (semi-IPN) and loaded with 5-fluorouracil. In vitro release studies showed faster release for semi-IPN microspheres compared to pure CH samples, and the total release was achieved in about 20–30 days, depending on the composition. In vitro cell studies were achieved against human breast adenocarcinoma cell line cells where adsorption of cells on microspheres with a significant decrease in their number was obtained. Meanwhile, the CH-PVP films, which were prepared with the same compositions as in the microspheres, demonstrated an increase in strength from 66 to 118 MPa as the PVP content was decreased. It can be concluded that the prepared CH-PVP semi-IPN microspheres are novel promising carriers compared to pure CH microspheres since it becomes possible to adjust stability and hydrophilicity of the microspheres as well as the release rates of the drugs from the microspheres by changing the ratio of CH/PVP composition.

A Novel Chitosan/Polyvinyl Pyrrolidone (CS/PVP) Three-Dimensional Composite and Its Mechanism of Strength Improvement

Novel biodegradable three-dimensional (3D) composites with good mechanical properties have been prepared by coagulation of a chitosan/polyvinyl pyrrolidone (CS/PVP) solution in NaOH. For example, the strength and modulus of CS/PVP (1/1) were 82.5 MPa and 1.86 GPa, increasing 237% and 644% compared with CS, respectively. Scanning electron microscopy and Fourier transform infrared analysis suggest that the PVP component did not dissolve during the preparation process. The nonsolution of the composites is attributed to the extremely strong hydrogen bonding formed between the CS and PVP macromolecules. It was also found that there are synergistic effects between the formation of hydrogen bonding with PVP and cross-linking with glutaraldehyde (GA) for the improvement in the mechanical properties of CS. The mechanism of strength improvement has been discussed thoroughly from the aspects of free volume.

Characterization of muco- and bioadhesive properties of chitosan, PVP, and chitosan/PVP blends and release of amoxicillin from alginate beads coated with chitosan/PVP

Purpose: To investigate the muco/bioadhesive properties of chitosan, polyvinylpyrrolidone (PVP), and chitosan/PVP blends and the release of amoxicillin (AMX) contained in AMX-alginate beads coated with these materials. Method: Chitosan, PVP, and chitosan/PVP blends at various volume ratios were coated onto calcium alginate beads containing AMX. The muco/bioadhesive properties of all materials and the AMX-alginate beads coated with these materials were characterized. Results: Measurements of their viscosity, texture, and adhesion to HT29 cells demonstrated that chitosan/PVP at a volume ratio of 5/5 had the best muco/bioadhesive properties when compared with chitosan, PVP, and blends of other ratios. Wash-off tests indicated that the mucoadhesive property of the coated AMX-alginate beads was significantly higher than that of the uncoated beads. Diffuse reflectance infrared Fourier transform spectroscopy showed that there were interactions between chitosan–PVP, chitosan–mucin, PVP–mucin, and chitosan/PVP blend–mucin. Scanning electron microscopy revealed that the surfaces of the coated beads were smoother than those of the uncoated beads. All coated AMX-alginate beads were able to provide a controlled release of AMX with Super Case II transport properties, at a pH of 4. This was probably a result of the rapid and extensive swelling of the alginate beads. The more rapid release of AMX at pH 1 was probably because of the rapid dissolution of the drug at this pH. Conclusions: From the controlled drug release and muco/bioahesive properties of these coated AMX-alginate beads, we suggest that the alginate-coated beads might be a promising drug delivery system to assist with the eradication of Helicobacter pylori infections.

γ-irradiated chitosan-polyvinyl pyrrolidone hydrogels as pH-sensitive protein delivery system

The effects of pH of the buffer solution and the composition of the hydrogel system on the bovine serum albumin (BSA) adsorption capacity of chitosan (CS)–polyvinyl pyrrolidone (PVP) (CSPVP) hydrogels and release of BSA were investigated. Poly-electrolyte CSPVP hydrogels with different compositions were prepared by irradiating CS/PVP/water mixtures with γ-rays at ambient temperature. The adsorption capacity of hydrogels was found to increase from 0 to 350 mg BSA/g dry gel, by changing external stimuli and hydrogel composition. The adsorption of BSA within CSPVP hydrogels increased with increase in CS content in the hydrogels. When the irradiation doses of hydrogel increased, the adsorption of BSA decreased. The maximum adsorption of BSA was observed at pH 5. A significant amount of the adsorbed BSA (up to 95%) was eluted in the phosphate medium containing 0.1 M NaCl at pH 7.4.

Dielectric and interaction behavior of chitosan/polyvinyl alcohol and chitosan/polyvinyl pyrrolidone blends with some antimicrobial activities

The blends of chitosan, polyvinyl alcohol and chitosan polyvinyl pyrrolidone in dilute acetic acid were found to be compatible by viscosity measurements. The dielectric behavior of the investigated blends were studied using frequency response analyzer covering a frequency range from 10 2 to 10 6 Hz and in a wide range of temperature. The permittivity ε′ was found to decrease by increasing the frequency showing an anomalous dispersion. The dielectric loss ε″ data on the frequency domain were found to be broad indicating that more than one relaxation mechanism is present. The data for the whole investigated systems were fitted using Fröhlich and/or Havriliak–Negami functions in addition to the conductivity term. The function detected below T g could be ascribed to an orientation movement related to the side chain. A second function in the lower frequency range could be ascribed as a Maxwell Wagner effect which arises from the interfacial polarization caused by the multi-constituents of the investigated systems. The biological activity of such investigated systems was tested against a representative number of pathogenic organisms by determining the minimum inhibitory concentration (MIC). The activity was found to increase by increasing the amount of CS in the blend.

Radiation synthesis and characterization of stimuli-sensitive chitosan–polyvinyl pyrrolidone hydrogels

Novel cationic hydrogels were synthesized by γ-irradiation copolymerization of chitosan and polyvinyl pyrrolidone (PVP). The synthesis regularities and the swelling behaviour of hydrogels have been studied. It was shown that increasing of PVP concentration in feed composition also as radiation dose accompanied of increase of yield of gel fraction and decrease of swelling degree. At dose more than 3.5 kGy increasing of swelling degree and decreasing of gel fraction yield have been observed. It was shown that the hydrogels exhibit pH-sensitive behaviour in aqueous solution. In solutions of sodium dodecyl sulfate (SDS) the hydrogels are collapsed due to complexation, however, at concentration of SDS solution equal to critical micelle concentration the gels contracted and then swollen again.