Chitosan Carboxymethyl Cellulose Research Articles

Evaluation of the Effect of Nanocoating on Mechanical and Biofilm Formation in Thermoplastic Polyurethane Aligner Sheets.

The objective of this research is to determine whether the thermoplastic polyurethane (TPU) coated with carboxymethylcellulose chitosan has better mechanical and antibacterial action (anti-Streptococcus mutans) when utilized in intraoral simulations with synthetic saliva. The TPU sheets (n = 45) were divided into three groups. Control (n = 15) consists of as-received TPU sheets. Test 1 consists of TPU sheets coated with carboxymethyl cellulose (CMC) chitosan (CHI) (n = 15). Test 2 consists of thermoformed nano-coated TPU (n = 15). For the polyurethane sheets, CHI-CMC sheets, and thermoformed CHI-CMC sheets, scanning electron microscopy (SEM) and three-point flexural tests were conducted and assessed. The materials testing software was used to calculate the elastic modulus and tensile strength. To study the bacterial accumulation, the cut circles of the TPU aligner were placed in centrifuge tubes with 2.5 mL of bacterial suspension at a concentration of 104 or 105 CFU/mL. SEM was done to assess the presence of cell growth in all three groups. According to SEM analyses of bacterial buildup, the coated TPU had minimal biofilms compared to the bare TPUs numerous biofilms. The effect of aging on coating thickness reveals that the thickness of thermoformed coated TPU films dramatically decreased over time, while the thickness of coated TPU films was maintained. When TPU is coated with CMC/CHI, the elastic modulus and tensile strength were observed to improve. The development of a super-hydrophilic coating by the CHI CMC coating on TPU sheets improved the coating's biocompatibility while also changing the shape of the multilayer film to prevent bacterial adhesion. The effect on the improvement in the mechanical properties diminished after the material underwent a thermoforming process. It is therefore suggested that the nanofilm be used in therapeutic applications following the thermoforming process.

Control of postharvest fungal decay in papaya fruits by chitosan-carboxymethyl cellulose coating incorporated with essential oils and potassium sorbate

Control of postharvest fungal decay in papaya fruits by chitosan-carboxymethyl cellulose coating incorporated with essential oils and potassium sorbate

Preparation, characterization, and evaluation of multi–biofunctional properties of a novel chitosan–carboxymethylcellulose–Pluronic P123 hydrogel membranes loaded with tetracycline hydrochloride

Herein, we report a multifunctional hydrogel membrane with good mechanical properties, excellent antioxidant efficiency, and broad-spectrum antimicrobial activity. For this purpose, a series of chitosan–carboxymethyl cellulose–Pluronic P123 (CHT–CMC–P123) hydrogel membranes were prepared by blending various tetracycline hydrochloride (TCH) contents. The physicochemical and biological properties of CHT–CMC–P123 membranes were comprehensively investigated. With the increase of TCH content from 5 % to 20 %, hydrogel membranes presented a decreased water contact angle from 18.96° to 11.24°, and a decreased water vapor transmission rate from 171.8 to 156.1 g/m2 h. Besides, with the increase of TCH content (5–20 %), the tensile strength (0.31–0.11 MPa) and elongation at break (10.57–4.82 %) of hydrogel membranes decreased while their thickness increased (113.5–324.3 μm). The data show that the release of TCH reached equilibrium after 26 days, with a cumulative percentage of approximately 28 %–87 %. Moreover, the hydrogel membranes exhibited a high antioxidant capacity of ~92 % for DPPH radical. Importantly, the incorporation of TCH significantly (~2.3 fold) enhanced the antimicrobial activity of the hydrogel membranes against Gram-positive, and Gram-negative bacteria and yeast. Based on our findings, these hydrogel membranes with superior properties may serve as effective food packaging and wound healing materials.

In-situ forming hydrogel based on thiolated chitosan/carboxymethyl cellulose (CMC) containing borate bioactive glass for wound healing

Suitable wound dressings for accelerating wound healing are actively being designed and synthesised. In this study, thiolated chitosan (tCh)/oxidized carboxymethyl cellulose (OCMC) hydrogel containing Cu-doped borate bioglass (BG) was developed as a wound dressing to improve wound healing in a full-thickness skin defect of mouse animal model. Thiolation was used to incorporate thiol groups into chitosan (Ch) to enhance its water solubility and mucoadhesion characteristics. Here, the in situ forming hydrogel was successfully developed using the Schiff-based reaction, and its physio-chemical and antibacterial characteristics were examined. Borate BG was also incorporated in the generated hydrogel to promote angiogenesis and tissue regeneration at the wound site. Investigations of in vitro cytotoxicity assays demonstrated that the synthesised hydrogels showed good biocompatibility and promoted cell growth. These results inspired us to investigate the effectiveness of skin wound healing in a mouse model. On the backs of animals, two full-thickness wounds were created and treated utilising two different treatment conditions: (1) OCMC/tCh hydrogel, (2) OCMC/tCh/borate BG, and (3) control defect. The wound closure ratio, collagen deposition, and angiogenesis activity were measured after 14 days to determine the healing efficacy of the in situ hydrogels used as wound dressings. Overall, the hydrogel containing borate BG was maintained in the defect site, healing efficiency was replicable, and wound healing was apparent. In conclusion, we found consistent angiogenesis, remodelling, and accelerated wound healing, which we propose may have beneficial effects on the repair of skin defects.

Ionic liquid-plasticised composites of chitosan and hybrid 1D and 2D nanofillers

The focus of this research was to study the effect of combining nanofillers with different geometry and surface chemistry on the structure and properties of biopolymers as an alternative to traditional plastics. How the inclusion of 2D graphene oxide (GO) or reduced GO (rGO) combined with 1D sepiolite (SPT) or cellulose nanocrystals (CNCs) affect the structure and properties of chitosan and chitosan/carboxymethyl cellulose (CMC) materials was investigated. A 3D interconnected microstructure formed, composed of GO and SPT due to the strong interactions between these hydrophilic nanofillers. The chitosan/CMC/GO/SPT composite had the highest tensile strength (77.5 ± 1.2 MPa) and Young’s modulus (1925.9 ± 120.7 MPa). For the un-plasticised matrices, hydrophobic rGO nanosheets generally hindered the interaction of SPT or CNCs with the polysaccharides (chitosan and CMC) and consequently, composite properties were mainly determined by the rGO. However, for the chitosan matrix plasticised by 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]), rGO + CNCs or rGO + SPT disrupted polymer chain interactions more effectively than the nanofillers when added alone and resulted in the chitosan being more plasticised, as shown by increased chain mobility, ductility, and surface hydrophilicity. For the [C2mim][OAc]-plasticised chitosan/CMC matrix, the advantages of including hybrid fillers, rGO + CNCs or rGO + SPT, were also obtained, resulting in higher thermal stability and surface hydrophobicity.Graphical

Chemometrics and Signal Processing-Assisted Design of a Textile-Based Colorimetric Sensing Platform for Real-Time Monitoring of Glucose

Colorimetric analysis of biomarkers in biological fluids, such as sweat and saliva, using textile- and paper-based platforms promises to be a powerful point-of-care analytical tool. Despite exponential advances in material design, device fabrication and image processing over the past years, the majority of paper/fabric-based analytical strips and devices, thus far, are strictly restricted to controlled laboratory settings. In situ and real time monitoring of biological analytes using familiar garments or accessories are centered around electrochemical sensors. In contrast, colorimetric devices that can theoretically enable the quantification of analyte concentration when coupled with image capture devices (such as a smartphone cameras) are comparatively fewer and less advanced. Here, garment design strategies and various embodiments of wireless communication electronics are applied cooperatively to afford a noninvasive platform for quantitative monitoring of a test-bed biomarker, glucose. The electronics-embedded garments contain two functional parts: a functionalized cotton substrate with enzyme/chromogenic reagent and a near-field communication device. The enzyme/chromogenic reagent mixture is directed into a circular reservoir created on the cotton substrate via the capillary force of the cotton and hydrophobic wax barrier created via a cheap and simple wax-drawing technique. This wax barrier limits the irregular flow of the reagent mixture. The second part is a near-field-communication system that causes no irritation and discomfort to the skin. Once a smartphone is put at a close distance, the electronic system can enable the wireless transmission. A built-in application was developed to automatically detect the sensor spot via a signal processing pipeline and extract the R, G and B channel intensities for database construction and analysis.The chemical properties and geometric structures of the glucose sensor were optimized with the aid of a combinatorial method—materials optimization and mathematical optimization. The former aims to overcome the blurring and the loss of the signal due to enzyme washout from the detection zone under capillary forces exerted during wear. This problem was mitigated by immobilizing the enzyme inside a chitosan-carboxymethyl cellulose hybrid via a precisely controlled layer-by-layer deposition protocol. The sensor was further characterized by field-emission scanning electron microscopy (FESEM) to understand long term storage stability and surface morphology-dependent colorimetric response.A mathematical strategy was utilized for the design and selection of an optimal near-field measurement system. This optimization procedure is particularly important for commercialization. It aims to minimize the number of experiments and reduce the quantity of the chromogenic reagent mixture that needs to be deposited on the cotton substrate. Central composite designs were used to estimate the effect of individual variables (i.e. glucose oxidase concentration, horseradish peroxidase concentration and 3,3’,5,5’-Tetramethylbenzidine concentration) and their interactions on the optimization of the color intensity. The significance of the main and interaction effects and the applicability of the model were inferred from the analysis of variance (ANOVA). The optimum value was verified and validated with experimental results.This textile-based colorimetric sensing platform exhibits simple-to-fabricate, and cost-effective nature which might facilitate the broad commercial usage in health monitoring and clinical diagnosis.

Long-term pre-clinical evaluation of an injectable chitosan nanocellulose hydrogel with encapsulated adipose-derived stem cells in an ovine model for IVD regeneration.

The potential therapeutic benefit of adipose-derived stem cells (ASCs) encapsulated in an injectable hydrogel for stimulating intervertebral disc (IVD) regeneration has been assessed by a number of translational and preclinical studies. However, previous work has been primarily limited to small animal models and short-term outcomes of only a few weeks. Long-term studies in representative large animal models are crucial for translation into clinical success, especially for permanent stabilization of major defects such as disc herniation. An injectable chitosan carboxymethyl cellulose hydrogel scaffold loaded with ASCs was evaluated regarding its intraoperative handling, crosslinking kinetics, cell viability, fully-crosslinked viscoelasticity, and long-term therapeutic effects in an ovine model. Three IVDs per animal were damaged in 10 sheep. Subcutaneous adipose tissue was the source for autologous ASCs. Six weeks after IVD damage, two of the damaged IVDs were treated via ASC-loaded hydrogel injection. After 12months following the implantation, IVD disc height and histological and cellular changes were assessed. This system was reliable and easy to handle intraoperatively. Over 12months, IVD height was stabilized and degeneration progression significantly mitigated compared to untreated, damaged IVDs. Here we show for the first time in a large animal model that an injectable chitosan carboxymethyl cellulose hydrogel system with encapsulated ASCs is able to affect long-term stabilization of an injured IVD and significantly decrease degeneration processes as compared to controls.

Dual loading of Nigella sativa oil-atorvastatin in chitosan–carboxymethyl cellulose nanogel as a transdermal delivery system

Both Nigella sativa oil and atorvastatin possess anti-inflammatory, immunomodulatory, antioxidant, and antibacterial properties that benefit wound healing. In this work, chitosan–carboxymethyl cellulose was loaded on N. sativa oil to synthesize oil nanogel (ONG) which was later used to load with atorvastatin to obtain atorvastatin-oil nanogel (ATONG). Evaluation of the particle size of ONG and ATONG proved the average of 172 and 193 nm, and their surface charges were found to be 32.2 and 34.7 mV, respectively. Transmission electron microscopy of the sample showed that the particles had homogeneous size distributions with spherical structures. Moreover, drug loading efficiency, drug release, and stability of ATONG were investigated, and their results confirmed the appropriate loading and release of atorvastatin. Cytotoxicity evaluation demonstrated that ATONG can safely release atorvastatin intracellularly in fibroblasts. Results from in vitro skin permeation of ONG and ATONG also revealed that the nanogels (NGs) has proper flux through the skin layers. The in vitro wound closure assay for ATONG verified the proliferation and migration capabilities of fibroblasts, confirming the positive effect on wound-healing applications. In scratch model of fibroblasts, the treatment with ATONG resulted in an increase in the expression of the FGF2, TGF-β1, and VEGF genes involved in fibroblast proliferation and migration aimed at wound healing (p < .001). ATONG, also demonstrated bactericidal effects against Staphylococcus, S. aureus, and S. epidermidis species. Based on the results, ONG and ATONG exhibited great potential to be used as a transdermal drug carrier and skin wound healing NG, respectively.

Cooperative Effects of Cellulose Nanocrystals and Sepiolite When Combined on Ionic Liquid Plasticised Chitosan Materials.

Cellulose nanocrystals (CNCs) and/or sepiolite (SPT) were thermomechanically mixed with un-plasticised chitosan and chitosan/carboxymethyl cellulose (CMC) blends plasticised with 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]). Examination of the morphology of these materials indicates that SPT aggregates were reduced when CNCs or [C2mim][OAc] were present. Inclusion of CNCs and/or SPT had a greater effect on material properties when the matrices were un-plasticised. Addition of SPT or CNCs altered the crystalline structure of the un-plasticised chitosan matrix. Moreover, a combination of SPT and CNCs was more effective at suppressing re-crystallisation. Nonetheless, the mechanical properties and surface hydrophobicity were more related to CNC/SPT–biopolymer interactions. The un-plasticised bionanocomposites generally showed increased relaxation temperatures, enhanced tensile strength, and reduced surface wettability. For the [C2mim][OAc] plasticised matrices, the ionic liquid (IL) dominates the interactions with the biopolymers such that the effect of the nanofillers is diminished. However, for the [C2mim][OAc] plasticised chitosan/CMC matrix, CNCs and SPT acted synergistically suppressing re-crystallisation but resulting in increased tensile strength.

Influence of plasticiser type and nanoclay on the properties of chitosan-based materials

Chitosan, a biocompatible polysaccharide having antimicrobial efficacy, is highly useful for biomedical and other applications. How chitosan properties can be tailored continues to attract intense research interest. Herein, chitosan and chitosan/carboxymethyl cellulose (CMC) materials filled with montmorillonite (MMT) were thermomechanically processed resulting in excellent nanoclay dispersion. Inclusion of MMT significantly increased molecular relaxation temperatures, tensile mechanical properties, and film surface hydrophobicity. When plasticisers such as 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) or glycerol were introduced, the effect of MMT on the biopolymer properties largely depends on whether the MMT alters plasticiser–biopolymer interactions. [C2mim][OAc]-plasticised chitosan exhibited a relatively high contact angle (100 ± 7°) similar to the un-plasticised chitosan/MMT material, derived from the strong hydrogen-bonding capability of [C2mim][OAc]. Polyelectrolyte complexation (PEC) allowed the glycerol-plasticised chitosan/CMC material to have a hydrophobic surface (contact angle: 90 ± 6°) similar to that of the un-plasticised chitosan/CMC/MMT material. Specifically, further inclusion of MMT interrupted biopolymer–plasticiser interactions, leading to increased surface wettability. However, while addition of [C2mim][OAc] resulted in reduced hydrophilicity of the chitosan/CMC matrix, addition of MMT counteracted this effect by interacting with the IL. This work shows the plasticisers and MMT influence surface hydrophilicity mainly by determining the availability of free biopolymer polar groups.

Microencapsulation of copigmented anthocyanins using double emulsion followed by complex coacervation: Preparation, characterization and stability

This work focused on anthocyanin-rich black rice extract (ATC) and copigmented anthocyanins (ATC-CTC) microencapsulation using double emulsion and complex coacervation with different hydrophilic emulsifiers (gelatin-acacia gum: GE-AG, chitosan-carboxymethyl cellulose: CS-CMC). Four freeze-dried microcapsule types (GE-AG/ATC, GE-AG/ATC-CTC, CS-CMC/ATC, and CS-CMC/ATC-CTC) were prepared. Morphology, microencapsulation yield, and physical and chemical properties were investigated. Complex coacervated double emulsions prepared with GE-AG and CS-CMC were morphologically representative of multiple and single cores, respectively. GE-AG/ATC-CTC had the most desirable chemical properties with high anthocyanin content (0.76 g/100 g dw) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS•+) scavenging activity (5.8 μg Trolox/100 g dw). Fourier transform infrared spectroscopy confirmed the hydrophilic emulsifier's electrostatic interactions between protonated amines and carboxylate. X-ray diffraction spectra of all microcapsules indicated their amorphous structure. During storage, CS-CMC/ATC-CTC had the highest anthocyanin stability, the lowest reaction rate constant (4.8 × 10−3 day−1), and the highest values for half-life (150 days), decimal reduction time (497 days), thermal resistance temperature (78.1 °C), as well as the lowest activation energy (23.7 kJ/mol). According to the thermodynamic properties, the copigmentation contributed to lower negative entropy (ΔS), and the enthalpy (ΔH), and Gibb's free energy (ΔG) suggested that the microencapsulated anthocyanin degradation reaction was endothermic and spontaneous.

Stabilization of zero-valent Au nanoparticles on carboxymethyl cellulose layer coated on chitosan-CBV 780 zeolite Y sheets: assessment in the reduction of 4-nitrophenol and dyes

Performance of polymer-based Au catalysis depends on the size of Au particles and the structure of polymer host materials. In the current studies, the carboxymethyl cellulose-chitosan (CMC-CH) sheet was synthesized by layering CMC on CH sheet, while CMC-CH-CBV 780 zeolite Y (CMC-CHZY) sheet was synthesized by coating the CMC layer on a sheet of CH-incorporated CBV 780 zeolite Y (ZY). The CMC-CH or CMC-CHZY sheets were individually immersed in Au(III) salt solution, which was converted to Au0 NPs by treating with NaBH4 to synthesize Au/CMC-CH or Au/CMC-CHZY catalysts respectively. Both the synthesized Au catalyst activities were compared against the discoloration of methylene blue (MB) and Congo red (CR) dyes as well as the reduction of 4-nitrophenol (4-NP). It was revealed that Au/CMC-CHZY catalyst showed excellent catalytic performance against all the pollutants. Furthermore, the apparent rate constant kapp (3.3 $$\times$$ 10−1 min−1), of Au/CMC-CHZY catalyst was found higher against MB dye discoloration as compared to CR and 4-NP. It was also observed that MB discoloration followed pseudo-first-order while CR and 4-NP followed the zeroth-order kinetics. The catalyst alters the mechanism of a chemical reaction and so does the order of the reaction, therefore, observed different orders of reaction in the current study.

Ionic Liquid (1-Ethyl-3-methylimidazolium Acetate) Plasticization of Chitosan-Based Bionanocomposites.

The structure and properties of different biopolymer composites based on chitosan and chitosan/carboxymethyl cellulose (CMC) are governed by multiple structure–property relationships associated with different phase interactions. Plasticization of these matrices with ionic liquid 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) played a dominant role, increasing the mobility of biopolymer chains as well as ions and associated dipoles but reducing biopolymer chain interactions, crystallinity, and thermal stability. These structural changes led to higher matrix ionic conductivity, shorter electrical relaxation time, and greater matrix ductility. The inclusion of graphene oxide (GO) and reduced GO (rGO) also influenced the structure and properties of these bionanocomposites by disrupting the biopolymer hydrogen bonding and/or polyelectrolyte complexation (PEC) and interacting with [C2mim][OAc]. The impact of GO/rGO was more evident for 20 wt % [C2mim][OAc], such as increased crystallinity and thermal stability of chitosan. PEC was hindered with excess (40 wt %) [C2mim][OAc] added and further hindered again when rGO was included. This study shows that the structure and properties of bionanocomposites are not just determined by the surface chemistry of GO/rGO but can also be influenced by multiple interactions involving plasticizers such as ILs and additional biopolymers.

Glycerol plasticisation of chitosan/carboxymethyl cellulose composites: Role of interactions in determining structure and properties

Biopolymers such as chitosan and cellulose continue to attract much interest as they have many appealing characteristics such as biodegradability, biocompatibility, chemical versatility and natural functionality; however, many of their properties usually require further tailoring for specific purposes. This study shows that glycerol plasticisation and the addition of graphene oxide (GO) or reduced graphene oxide (rGO) altered the properties of chitosan and a chitosan/carboxymethyl cellulose (CMC) blend. For the chitosan/CMC matrix, GO or rGO was likely to disrupt polyelectrolyte complexation (PEC) between the two biopolymers, leading to weakened mechanical properties and increased surface hydrophilicity. Conversely, glycerol assisted PEC by increasing the biopolymer chain mobility, leading to reduced surface hydrophilicity. Moreover, some synergistic effects from a combination of glycerol and GO/rGO were evident. Specifically, GO/rGO notably increased the toughness of the chitosan film on inclusion of 40 wt% glycerol. Both GO and rGO reduced the relaxation temperatures of the chitosan/CMC film with 20 wt% glycerol added, resulting in increased biopolymer chain mobility. Moreover, the bionanocomposites showed high relative permittivity (54–387). Thus, this work describes how complex interactions in multiphasic biopolymer composite systems influence structure and properties.

Structure and properties of thermomechanically processed chitosan/carboxymethyl cellulose/graphene oxide polyelectrolyte complexed bionanocomposites

Bionanocomposites of chitosan and chitosan/carboxymethyl cellulose (CMC) polyelectrolyte complexed materials with graphene oxide (GO) or reduced graphene oxide (rGO) were prepared by thermomechanical processing with excellent levels of dispersion. While GO has a greater affinity with the chitosan polycation, rGO had a more pronounced effect on properties resulting in increased tensile strength, Shore D hardness, and thermal stability of both matrices. Although GO is more hydrophilic than rGO, the former increased more effectively the surface hydrophobicity of the biocomposites regardless of matrix type. GO and rGO changed the α-transition of the biocomposites in a similar manner. The electrochemical properties of the biocomposites were influenced by both nanofiller type and matrix. This research revealed that inclusion of 2D carbon nanomaterials can alter biopolymer interactions and that the phase structure of the biopolymer blend may play a more important role than nanofiller–matrix interactions in determining the overall properties of these bionanocomposites.

Amylase loading on a commercial nylon bandage intended for the control delivery of drug in treating localized wounds

Layer-by-Layer assembly process has been reported of the ability to construct a hydrolytically degradable drugs depot on a commercially available bandage, which can release the drug directly into a wound bed and dramatically change the gene exposure. In this work, a commercial bandage was coated with amylase via layer-by-layer (LbL) in order to obtain nanoscale layers of amylase for intended control drug delivery in treating localized wounds. Meanwhile, the commercial bandage was initially plasma-cleansed for five (5) minutes before it was mounted on to a dipping machine. LbL assembly using chitosan/carboxymethyl cellulose (CMC) was designed by alternate adsorption unto the commercial bandage. Furthermore, amylase was incorporated into the polymeric network of the film by using electrostatic interactions, hydrogen bonds and hydrophobic interactions. A carpet layer of 10 repeats of LbL was formed on the bandage by alternate coating of chitosan and carboxymethyl cellulose (CMC). On to this base layer, another 20 repeats was performed for loading of the amylase on to the base layer. Two solutions of amylase were used with the same concentration of 2 mg/ml, but different pHs of 4.5 and 5.8 in order to study the effect of pH on the nano-coating. Another 5 LbL repeats of chitosan/CMC was conducted in order to form the network of the self-assembled nano-coating LbL. The nano-coating was characterized by morphological and physico-chemical analyses in order to evaluate the multilayered structure. All the experiments were conducted at room temperature.

Chitosan-Based Layer-by-Layer Assembly: Towards Application on Quality Maintenance of Lemon Fruits

We fabricated a novel chitosan-carboxymethyl cellulose (CMC) layer-by-layer assembly system to facilitate the postharvest quality of the fresh produce. Fourier transform infrared spectroscopy (FTIR), TA-XT2 texture analyzer, water vapor permeability (WVP) analyzer, and scanning electron microscopy (SEM) were applied to compare the properties of chitosan and layer-by-layer assembly. The strategy involved the optimization of water vapor permeability, puncture strength, and elasticity properties of multiplayer polymer coating. Results showed that the lemon (Citrus limon (L.) Burm. f.), coated by chitosan-CMC layer-by-layer assembly, displayed significantly higher lemon firmness and vitamin C content with excellent morphology, as well as inhibited weight loss and flesh browning. This study could provide support for quality maintenance in the fruit and vegetable industry and make a significant contribution to the utilization of the natural polysaccharide as a viable resource.

Synthesis, Characterization, Kinetics, and Thermodynamics of EDTA-Modified Chitosan-Carboxymethyl Cellulose as Cu(II) Ion Adsorbent.

A new adsorbent derived from the naturally occurring biopolymers, chitosan (CS) and carboxymethyl cellulose (CMC) was prepared by cross-linking them using EDTA. EDTA having high affinity for metal ions can be used to enhance the chelation properties of the adsorbent enormously. The product obtained (chitosan-EDTA-CMC, CSECM) was characterized by different techniques: FTIR, XRD, SEM/EDAX, TGA, and XPS. The parameters for evaluation of the adsorption properties for removal of Cu(II) ions from the aqueous solution were determined using the batch adsorption method by studying the effect of pH, contact time, initial ion concentration, and temperature on adsorption. Pseudo-first-order, pseudo-second-order, and intraparticle diffusion kinetic models were applied to study the kinetics of the adsorption process, whereas Langmuir, Freundlich, Temkin, and D-R models were applied to evaluate the thermodynamics of the adsorption process. The kinetic adsorption parameters were in best agreement with the pseudo-second-order model, while thermodynamic parameters best fitted to the Langmuir isotherm at different temperatures for adsorption of Cu(II) ions from aqueous solution with a maximum adsorption capacity of 142.95 mg/g at pH 5.5. CSECM showed excellent regeneration capability and recovery of the Cu(II) ion up to five cycles without the loss of the adsorption efficiency, which is the best characteristic to select the appropriate choice of the adsorbent. The adsorbent was also employed in batch experiments to evaluate the adsorption of hardness, producing common metal ions in single and real wastewater solutions.

Development of bioactive composite films from chitosan and carboxymethyl cellulose using glutaraldehyde, cinnamon essential oil and oleic acid

In the present research the effect of incorporating cinnamon essential oil (CEO), oleic acid (OA) and glutaraldehyde (GL) on antimicrobial, antioxidant, mechanical, physical and morphological properties of chitosan-carboxymethyl cellulose composite films were investigated. Cross-linking effect of GL (as determined by FTIR analysis) significantly resulted in higher mechanical strength and lower water vapor permeability (WVP). Cross-linked films incorporated with CEO revealed higher and steady state antioxidant activity as well as in vitro antimicrobial properties against Listeria monocytogenes and Pseudomonas aeruginosa. Thickness, elongation at break (EAB) and WVP increased by including OA; however, water solubility significantly decreased. Color properties and microstructure of composite films were significantly affected by the additives as confirmed by SEM analyses. We showed that the antimicrobial, antioxidant, mechanical and physical properties of chitosan-carboxymethyl cellulose composite films could be improved via incorporating CEO and GL to the film matrix.

In vitro evaluation of alpha-tocopherol loaded carboxymethylcellulose chitosan copolymers as wound dressing materials

ABSTRACTThe hydrogel is a biopolymer exhibiting swelling behaviour involving a significant amount of water due to its insoluble, three-dimensional network structure when exposed to the aqueous medium, and allows its use in wound dressings. In the present study, a hydrogel was synthesized from chitosan and carboxymethylcellulose (CMC) polymers as a result of a chemical reaction at which N,N’-methylenebisacrylamide (MBA) was used as a cross-linker and ammonium persulfate (APS) as initiator-catalyst. Characteristic features of the synthesized hydrogel were determined by FTIR (Fourier Transform Infrared Spectroscopy), BET (Brunauer, Emmet and Teller) analyses. Alpha-Tocopherol release profile from the membrane was determined via ESI-MS using LC/Q-TOF. Cell adhesion and proliferation was observed by 3-[4,5-dimethyl-2-thiazolyl]-diphenyl tetrazolium bromide (MTT) method. The results revealed that hydrogels loaded alpha-Tocopherol is efficient for stimulating the healing process.