M. Swathi; Pratik Roy; M. V. Deepthi; Sailaja RRN
Abstract
In this study chitosan (CTS) has been grafted with itaconic acid (IA) by following microwave assisted grafting method. Three different types of nanomaterials namely nanoclay, cloisite 30B and multiwalled carbon nanotubes (MWCNT) have also been incorporated during the grafting reaction. The synthesized ...
Read More
In this study chitosan (CTS) has been grafted with itaconic acid (IA) by following microwave assisted grafting method. Three different types of nanomaterials namely nanoclay, cloisite 30B and multiwalled carbon nanotubes (MWCNT) have also been incorporated during the grafting reaction. The synthesized nanocomposites were used for the removal of napthol green, reactive black and congo red dyes from aqueous solutions. Results showed enhanced dye adsorption capacity after addition of nanomaterials. The adsorption isotherm fitted well with Langmuir model. It was observed that CTS grafted IA composite with cloisite 30B exhibited highest napthol green adsorption rate compared to others. CTS grafted IA composite with MWCNT showed better congo red and reactive black adsorption rate as compared to CTS nanocomposite modified with nanoclay and cloisite 30B. The swelling kinetics in acidic, basic and neutral medium was found to follow pseudo second order kinetic model. Fourier transform infrared spectroscopy (FTIR) analysis showed successful grafting of IA on CTS. X-ray diffraction (XRD) and morphological characteristics suggested enhanced dispersion of nanomaterials in CTS matrix.
Evi Yulianti; Indra Hartono; Sudaryanto .; Deswita .; Mashadi .
Abstract
Solid Polymer Electrolyte (SPE) has great potential in replacing liquid electrolytes. The SPE has many advantages such as high thermal stability, good flexibility, and non-flammable. One of the polymers that can be used is chitosan biopolymer from shrimp skin extraction. Generally, polymers are isolators ...
Read More
Solid Polymer Electrolyte (SPE) has great potential in replacing liquid electrolytes. The SPE has many advantages such as high thermal stability, good flexibility, and non-flammable. One of the polymers that can be used is chitosan biopolymer from shrimp skin extraction. Generally, polymers are isolators and have low ionic conductivity, so that modification to the structure of chitosan is needed to increase the ionic conductivity. One way to modify the chitosan structure is by plasticizer addition. In this study the addition of sorbitol plasticizer was carried out with a variation between 0, 20, 40, 60 and 80 (in weight percent) which is called as CA for pure chitosan, CA1, CA2, CA3, CA4 and CA5 respectively. The synthesis of chitosan electrolyte film was prepared by casting method. Then qualitative and quantitative analysis was carried out by using X-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS), and mechanical properties. Optimal composition was obtained by 40% (in weight percent) sorbitol addition with a conductivity of 3.74 ´ 10 -5 S.cm -1 . XRD measurement shows more amorphous polymers with more sorbitol addition. The sorbitol addition also increases the tensile strength, elongation and Young modulus of film flexibility become 52.3%, and 158.3MPa and 19.8MPa, respectively.
Bhavani P. Nenavathu; Geetanjali
Abstract
An efficient theragnostic which offers diagnosis and therapy of cancer is developed using a polymer based nanocarrier embedded with fluorescent quantum dots by the ionotropic gelation method. The FTIR spectra provide direct evidence of formation of polymer based nanocarrier comprising chitosan-alginate ...
Read More
An efficient theragnostic which offers diagnosis and therapy of cancer is developed using a polymer based nanocarrier embedded with fluorescent quantum dots by the ionotropic gelation method. The FTIR spectra provide direct evidence of formation of polymer based nanocarrier comprising chitosan-alginate micro beads (CS-ALG beads). Notably, the SEM images showed highly porous structure of polymeric beads without Ag NPs and CdS QDs. The morphology of CS-ALG beads loaded with Ag NPs and CdS QDs showed smooth surface, glossy, homogenous shape under scanning electron microscopy and it could be due to high loading of fluorescent and silver NPs. The EDX analysis of as synthesised nanoparticle embedded polymeric beads showed X-ray peaks of Cd, S corresponds to CdS NPs. And the X- Ray peaks of C, O corresponds to the polymer beads. Characterization of nanocarrier for the presence of polymers has been confirmed by studies carried out using thermogravimetric analysis (TGA) showed complete degradation of Chitosan at about 450 °C while calcium alginate exhibits three-step decomposition. Further, the swelling studies of dried CS-ALG beads were carried out at room temperature and about 97% of swelling is being observed at pH 5 in 45 min. and 44% swelling is observed at pH 2. Copyright © VBRI Press.
Hadar Ben-Yoav; Marshall A. Schroeder; Malachi Noked
Abstract
Nanostructured electrodes enable a new generation of electrochemical sensors by increasing their surface area that lead to stronger signals generated by electrochemically-active molecules, such as diagnostic redox-active biomarkers. Yet, the selectivity of these translational sensors is far from being ...
Read More
Nanostructured electrodes enable a new generation of electrochemical sensors by increasing their surface area that lead to stronger signals generated by electrochemically-active molecules, such as diagnostic redox-active biomarkers. Yet, the selectivity of these translational sensors is far from being sufficient for discriminating between individual molecules in multicomponent samples, such as biofluids. Here, we propose an approach to improve the selectivity of nanostructured electrodes using a simple modification with a functional bio-polymer. Specifically, we demonstrate the targeted modification with a bio-polymer chitosan of carbon nanotubes organized in an array on a Au electrode. We describe the fabrication process and we show the characterization of the structural morphology and the electrochemical activity of the fabricated chitosan-modified carbon nanotube arrayed electrode. Electrochemical characterization yielded an increased effective surface area for the optimized carbon nanotube arrayed electrode (0.46 ± 0.03 cm 2 ) that was similar to the area of the unmodified Au electrode (0.48 ± 0.02 cm 2 ). Furthermore, despite decreased electrochemical current characteristics, we demonstrate the feasibility to modify individual carbon nanotubes with chitosan. The modification of the carbon nanostructures with chitosan will enable further functionalization with specific receptors, such as enzymes and antibodies that will provide the required selectivity towards biomarkers in multicomponent biofluids.
Faruq Mohammad; Hamad A. Al-Lohedan; Hafiz N. Al-Haque
Abstract
Hybrid materials based on metals and natural polymers are a promising class of nanocomposites; there is an increasing interest in metal nanoparticles (NPs) due to some fascinating characteristics associated with their nanosizes such as optical, conducting, catalytic, mechanical, sensing and superparamagnetic ...
Read More
Hybrid materials based on metals and natural polymers are a promising class of nanocomposites; there is an increasing interest in metal nanoparticles (NPs) due to some fascinating characteristics associated with their nanosizes such as optical, conducting, catalytic, mechanical, sensing and superparamagnetic properties. Despite these favorable properties, the natural tendency of NPs for aggregation, high reactivity due to surface charges, and high rate of toxicity are limiting their applicability in biomedical sector. Chitosan, a naturally available amino polysaccharide biopolymer obtained from the exoskeleton of crustaceans (crabs and shrimp) and cell walls of fungi, displays unique polycationic, porous, chelating, bioadhesive and film-forming properties. The in-built characteristics of chitosan biopolymer can be utilized to alter the negative shades of metal NPs, thereby enhancing the applications in many different areas. The incorporation of chitosan significantly affects the steric stabilization of metal colloids, creates extra functional groups for biomolecule conjugation, renders the NPs suitable for bio-markers, protects metal ions from further oxidation/reduction by means of polymer coordination and has a control over toxicity. Thus by taking advantage of the additional features offered by the combination of chitosan and metal NPs, this report is designed to provide an overview about the metal NPs type, synthesis and applications in bioengineering and biomedical sector. Starting with the influencing properties due to their combination, we further reviewed the literature related to chitosan and metal NPs applicable for medicine with a specific focus on cancer diagnosis and treatment, advanced drug delivery, tissue engineering and surgical aids, to mention some.
Moises Oviedo Mendoza; Edna M. Valenzuela-Acosta; Evgen Prokhorov; Gabriel Luna-Barcenas; Siva Kumar-Krishnan
Abstract
In this work, we report the relationship between the electrical conductivity and nanoparticle effective surface area with functional properties of polymer-metal and polymer-clay nanocomposites. Conductivity of the nanocomposite strongly depends upon metal/clay nanoparticle size and concentration that ...
Read More
In this work, we report the relationship between the electrical conductivity and nanoparticle effective surface area with functional properties of polymer-metal and polymer-clay nanocomposites. Conductivity of the nanocomposite strongly depends upon metal/clay nanoparticle size and concentration that ultimately dictate where the system percolates. Knowledge of percolation properties allows the design of functional nanocomposites for biomedical and sensors applications. Herein we report the successful production of three functional chitosan-metal/clay nanocomposites: a) chitosan-Ag films with antibacterial properties, b) chitosan-Au potentiometric sensor for detection of Cu ++ and c) chitosan-nanoclay potentiometric sensor for detection of NO3-. For all these applications the best functional performance of nanocomposites has been observed when NPs concentration increases and approaches the percolation threshold. The obtained relationship between electrical percolation threshold and functional properties of polymer nanocomposites is of primary importance in the design of high-performance applications.
Sandra Rivero; Maria A. Garcia; Adriana Pinotti
Abstract
The influence of natural antioxidants incorporated to biodegradable materials has become a focus of attention in the current food packaging research and development. Chitosan is a functional natural polymer extensively used for tailoring systems or matrices for a different active compound delivery. This ...
Read More
The influence of natural antioxidants incorporated to biodegradable materials has become a focus of attention in the current food packaging research and development. Chitosan is a functional natural polymer extensively used for tailoring systems or matrices for a different active compound delivery. This work was focused on studying the changes undergone by the chitosan matrix because of the addition of ferulic acid as an antioxidant. Thus, both microstructure and physical properties such as solubility, thermal stability, mechanical and barrier properties were monitored. The addition of ferulic acid caused a decrease in both the moisture content and water vapor permeability, an increase in resistance and a change at the structural level evidenced by TEM. Through FTIR spectra and their relationship with chitosan-based film properties, it was demonstrated that ferulic acid was effectively incorporated in the polymer matrix. The amount of the bioactive compound released from the chitosan matrix to a liquid medium was determined. The delivery profile suggested that the release of the antioxidant agent was controlled by two parallel mechanisms, one Fickian-type and the other associated to the high swelling of the matrix. The antioxidant and UV-barrier properties induced by the addition of ferulic acid turned the chitosan films into a potentially active material to be applied on high-fat foods.
S. Malathi; M. D. Balakumaran; P. T. Kalaichelvan; S. Balasubramanian
Abstract
Gold nanoparticles (AuNPs) have been synthesized by green method using chitosan as a reducing/capping agent. We designed a biocompatible carrier for controlled release of hydrophobic drugs. The designed carrier was prepared by using single oil-in-water (O/W) emulsion. The resulting AuNPs were characterized ...
Read More
Gold nanoparticles (AuNPs) have been synthesized by green method using chitosan as a reducing/capping agent. We designed a biocompatible carrier for controlled release of hydrophobic drugs. The designed carrier was prepared by using single oil-in-water (O/W) emulsion. The resulting AuNPs were characterized by UV–Vis spectroscopy (UV–Vis) and Fourier transform infrared spectroscopy (FTIR). The transmission electron microscopy (TEM) studies indicate the spherical nature of drug loaded nanoparticles with the size of 50nm while the average particle size of AuNPs is found to be 2-3nm. The chitosan capped AuNPs showed a surface plasmon resonance at 526nm. The FTIR spectra suggest that the amine group is mainly responsible for the reduction of tetrachloroauric acid and capping the AuNPs. The controlled release of rifampicin (RIF) was investigated by in vitro studies using phosphate buffer saline (PBS) at pH=7.4. The loading efficiency of drug molecule was found to be 71%. The encapsulated drugs were released at 37 °C temperature. The results have been fit into various mechanistic models and it is found that the Higuchi model fits in to the release behavior of RIF. Further, the antibacterial activity of RIF loaded nanoparticles was examined by Gram +ve (bacillus subtils) and Gram -ve (Pseudomonas aeruginosa) bacteria. The application of similar drug loaded nanocarrier for treating other diseases like cancer can also be investigated.
Afifa Bathool; Gowda D. Vishakante; Mohammed S. Khan; H.G. Shivakumar
Abstract
The aim of this study is to formulate and characterize atorvastatin loaded chitosan loaded nanoparticles prepared by solvent evaporation method for sustained release. Low oral bioavailability of Atorvastatin calcium (14%) due to an extensive high first-pass effect makes it as prime target for oral sustained ...
Read More
The aim of this study is to formulate and characterize atorvastatin loaded chitosan loaded nanoparticles prepared by solvent evaporation method for sustained release. Low oral bioavailability of Atorvastatin calcium (14%) due to an extensive high first-pass effect makes it as prime target for oral sustained drug delivery. Weighed amount of drug and polymer were dissolved in suitable organic solvent DMSO and 2% acetic acid as an organic phase. This solution is added drop wise to aqueous solution of Lutrol F68 and homogenized at 25000rpm followed by magnetic stirring for 4hrs. Nanoparticles were evaluated for its particle size, scanning electron microscopy (SEM), Fourier-Transform infrared spectroscopy (FTIR), percentage yield, drug entrapment and for in vitro release kinetics. Among the four different ratios, 1:4 ratio showed high drug loading and encapsulation efficiency. SEM studies shows that prepared nanoparticles were spherical in shape with a smooth surface. Particle size of prepared nanoparticles was found to be in range between 142 nm to 221 nm. FTIR and DSC shows drug to polymer compatibility ruling out any interactions. In vitro release study showed that the drug release was sustained up to 7 days. Hence, prepared nanoparticles proved to be promising dosage form for sustained drug delivery of atorvastatin reducing dosing frequency, thus increasing the patient compliance.
A. Santhana Krishna Kumar; S. Kalidhasan; Vidya Rajesh; N. Rajesh
Abstract
The microwave assisted preparation and characterization of chitosan-surfactant modified NaMMT clay composite material is discussed, followed by its interesting application to detoxify heavy metal chromium. Cr(VI) could be effectively adsorbed in a weakly acidic medium (pH 5) from a large sample volume. ...
Read More
The microwave assisted preparation and characterization of chitosan-surfactant modified NaMMT clay composite material is discussed, followed by its interesting application to detoxify heavy metal chromium. Cr(VI) could be effectively adsorbed in a weakly acidic medium (pH 5) from a large sample volume. The composite material before and after the adsorption of chromium was scrupulously characterized using FT-IR, SEM, XRD and EDX techniques. The XRD study revealed the crystalline nature of the composite material with sharp and symmetric peaks. The bichromate ion forms an ion-pair with the protonated amine group in chitosan and this is reflected in the appearance of a Cr=O peak at 916 cm -1 in IR study. The surface hydroxyl groups in clay can be protonated and this could also serve as a source of electrostatic interaction with the bichromate oxyanion. The material exhibited a superior adsorption capacity of 133 mg g -1 and the adsorption data fitted well with Langmuir and Freundlich isotherm models. The composite adsorbent material exhibits a pore size of 3.5 nm at a maximum pore volume of 0.16 cm 3 g -1 . The BET surface area of the material obtained from N2 adsorption was found to be 52 m 2 g -1 . The experimental data also showed a good correspondence to the pseudo-second-order kinetics and the sorption thermodynamics correlated to the endothermic nature of the adsorption. The adsorbent could be regenerated using ascorbic acid or sodium sulfite which is indicative of the greener aspect in the methodology.
Vivek Singh Chauhan; M. Yunus; Nalini Sankararamakrishnan
Abstract
A novel iron doped chitosan coated activated alumna (IDCA) derivative was prepared and spectroscopic studies including FTIR, Elemental analysis (EA), XRD, and SEM were used for its characterization. Thermodynamic behavior of the adsorbent was evaluated by Thermogravimetric Analysis (TGA) and Differential ...
Read More
A novel iron doped chitosan coated activated alumna (IDCA) derivative was prepared and spectroscopic studies including FTIR, Elemental analysis (EA), XRD, and SEM were used for its characterization. Thermodynamic behavior of the adsorbent was evaluated by Thermogravimetric Analysis (TGA) and Differential Scanning calorimetry (DSC) analysis. The pore size distribution and nitrogen adsorption isotherm revealed the existence of micro porous structure. The applicability of the adsorbent towards the removal of arsenite and arsenate has been demonstrated.
Ajit Kumar Sharma;Ajay Kumar Mishra
Abstract
In this study, we have synthesized chitosan-grafted-styrene (Ch-g-sty) without any radical initiator or catalyst using microwave (MW) irradiation. Ch-g-sty was synthesized with 187% grafting using 80 % MW power in 40 second at (styrene) 0.13 M, (Chitosan) 0.1 g/25 mL. On the other hand, under similar ...
Read More
In this study, we have synthesized chitosan-grafted-styrene (Ch-g-sty) without any radical initiator or catalyst using microwave (MW) irradiation. Ch-g-sty was synthesized with 187% grafting using 80 % MW power in 40 second at (styrene) 0.13 M, (Chitosan) 0.1 g/25 mL. On the other hand, under similar condition of concentration of styrene and chitosan, 148% grafting was observed with potassium persulphate (K2S2O8)/ascorbic acid as redox initiator and atmospheric oxygen as co-catalyst in 1 h using conventional method at 35 o C. Microwave synthesized Ch-g-sty copolymer was characterized by Fourier transform-Infrared (FTIR) spectroscopy, thermo gravimetric analysis (TGA), X-ray diffraction (XRD) measurement and scanning electron microscopy (SEM). Maximum grafting was optimized by varying the microwave power, exposure time and styrene/chitosan concentration. Ch-g-sty copolymer was found to be more efficient for Cr(VI) removal as compare to conventionally and parent chitosan in aqueous solution. Sorption of Cr(VI) was depending upon pH and concentration, with pH=3 being the optimum value. The equilibrium data followed the Langmuir isotherm model with maximum capacities of 526.3 mg/g, 312.5 mg/g and 166.7 mg/g for Ch-g-sty copolymer, conventional (thermostatic water bath) method and parent chitosan respectively.
Ajit Kumar Sharma;Ajay Kumar Mishra
Abstract
In this study, we have synthesized chitosan-grafted-styrene (Ch-g-sty) without any radical initiator or catalyst using microwave (MW) irradiation. Ch-g-sty was synthesized with 187% grafting using 80 % MW power in 40 second at (styrene) 0.13 M, (Chitosan) 0.1 g/25 mL. On the other hand, under similar ...
Read More
In this study, we have synthesized chitosan-grafted-styrene (Ch-g-sty) without any radical initiator or catalyst using microwave (MW) irradiation. Ch-g-sty was synthesized with 187% grafting using 80 % MW power in 40 second at (styrene) 0.13 M, (Chitosan) 0.1 g/25 mL. On the other hand, under similar condition of concentration of styrene and chitosan, 148% grafting was observed with potassium persulphate (K2S2O8)/ascorbic acid as redox initiator and atmospheric oxygen as co-catalyst in 1 h using conventional method at 35 o C. Microwave synthesized Ch-g-sty copolymer was characterized by Fourier transform-Infrared (FTIR) spectroscopy, thermo gravimetric analysis (TGA), X-ray diffraction (XRD) measurement and scanning electron microscopy (SEM). Maximum grafting was optimized by varying the microwave power, exposure time and styrene/chitosan concentration. Ch-g-sty copolymer was found to be more efficient for Cr(VI) removal as compare to conventionally and parent chitosan in aqueous solution. Sorption of Cr(VI) was depending upon pH and concentration, with pH=3 being the optimum value. The equilibrium data followed the Langmuir isotherm model with maximum capacities of 526.3 mg/g, 312.5 mg/g and 166.7 mg/g for Ch-g-sty copolymer, conventional (thermostatic water bath) method and parent chitosan respectively.
Zi-Ang Yao;Hai-Ge Wu
Abstract
In order to construct a suitable scaffold for corneal cell culture and transplantation in vitro, different chitosan-chondroitin sulfate blended membranes were prepared and the properties of blended membranes were studied. Corneal stroma cells and corneal endothelial cells were seeded onto the blended ...
Read More
In order to construct a suitable scaffold for corneal cell culture and transplantation in vitro, different chitosan-chondroitin sulfate blended membranes were prepared and the properties of blended membranes were studied. Corneal stroma cells and corneal endothelial cells were seeded onto the blended membrane surface and the effects of the blended membranes on corneal cell attachment and metabolism were investigated. The results showed that chitosan and chondroitin sulfate had good compatibility in blended membranes. Chondroitin sulfate improved the homogeneousness, crystallization, transparency, and tensile strength and decreased the water content of the blended membrane. Within the blending ratio of 1:0.1, chondroitin sulfate reduced the damage of chitosan membranes to cells and improved the biocompatibility between cells and membranes. Corneal cells grew and formed a confluent monolayer on chitosan-chondroitin sulfate blended membranes (CH-CS3). All results indicated that the blended membranes of chitosan and chondroitin sulfate could be used as a scaffold for corneal cell culture in vitro and have potential to be used as carriers for corneal endothelial cell transplantation.