Mixture Of Carboxymethyl Cellulose Research Articles

Antimicrobial and degradable all-cellulose composite for functional and sustainable food packaging

The investigation of environmentally friendly and sustainable replacement materials is consistently prompted by the mounting environmental concern over plastics derived from petrochemicals. Compared with fossil oil derived chemicals and materials, cellulose is more readily available, less expensive, and biodegradable. Herein, all-cellulose composite films with excellent biodegradability and antimicrobial activities were prepared for sustainable food package. The all-cellulose films were prepared by a simple solution cast method of amino cellulose and carboxymethyl cellulose mixture. Rheological studies suggest typical non-Newtonian and shear thinning behavior of the all-cellulose solution associated with strong intermolecular electrostatic interactions. Such composite results in package films with amorphous structure, and uniform, dense and smooth morphology. Properties explorations indicated that the all-cellulose composites films exhibited better mechanical properties, water vapor and oxygen barrier properties than conventional synthetic plastic packages. Besides, the all-cellulose films showed excellent antimicrobial activity, and biodegradability. When applied as shrimp package, the all-cellulose composite films effectively extended shelf-life of shrimp by inhibition of microbial and oxidative deterioration of shrimp meat. This study provides a feasible approach to syntheze biodegradable and antimicrobial functional food package from cellulose in replacing of traditional synthetic plastic films.

Synthesis of Linoleic Acid of Conjugated Isomers from Sesame (Sesamum Indicum) Seed Oil: Its Use and Effect in a Microstructured Product Type Oil-in-Water Emulsion

The development of functional foods is an area of great interest and innovation in the food industry. The use of conjugated linoleic acid (CLA) in food formulations has been growing in recent years due to its multiple health benefits. In this study, conjugated linoleic acid was obtained from sesame oil, and its use in the formulation of oil-in-water food emulsions was evaluated. Conjugated linoleic acid (CLA) was synthesized from the linoleic acid present in sesame oil using the alkaline isomerization method using proplyeneglycol as a solvent. The effect of alkali concentration (NaOH) and reaction time on the conversion of linoleic acid to CLA was evaluated. A 96.6% conversion of CLA was obtained with a NaOH concentration of 7% and a reaction time of 2 h. Emulsions were prepared using CLA as oil phase and soy lecithin, tween 80, carboxymethylcellulose as emulsifying agents. Emulsions with mixtures of carboxymethylcellulose and tween 80 were stable, presenting a non-Newtonian fluid behavior of pseudoplastic type (n<1). The Ostwald-de-Waele model shows an optimal fit to the experimental data of apparent viscosity (R2>0.99 ), and its microstructural characterization shows a homogeneous particle distribution. These results show that the alkaline isomerization process using propylene glycol as a solvent is an excellent alternative for the synthesis of CLA from vegetable oils such as sesame oil and its application in the development of microstructured products such as functional emulsions, and their subsequent application in the development of new food products with beneficial health characteristics.

ZIF-8 metal organic framework, carboxymethylcellulose and polyvinyl alcohol bio-nanocomposite controlled-release phosphorus fertilizer: Improved P management and tomato growth

This study is concerned with the synthesis, characterization, and application of bio-nanocomposite films using a mixture of carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA) integrated with zeolitic imidazolate type 8 (ZIF-8) nanoparticles (NPs). The advanced bio-nanocomposites were employed as a coating for triple superphosphate (TSP) fertilizers, and their impact on tomato plant growth was evaluated. The successful integration of ZIF-8 into the composite matrix was determined by distinct changes in Fourier transform infrared (FTIR) spectra, indicating significant structural modifications. Morphological analyses by scanning electron microscopy (SEM) revealed alterations in the surface characteristics of the CMC/PVA films. Furthermore, energy dispersive X-ray (EDX) analysis confirmed the elemental composition of the resulting nanocomposite. The precision-coated TSP fertilizers exhibited a notable enhancement in mechanical strength, as evidenced by their superior resistance to crushing. The coated TSP also exhibited a controlled release of phosphorus over time, prolonging the release of phosphorus for up to 9 days in water and 50 days in soil. In soil, the 0.5 % ZIF-8 NP coating delayed the release of phosphorus, with only 12.29 ± 2.75 % released after five days compared to 96.96 ± 2.03 % for uncoated TSP. The application of coated TSP fertilizers to tomato plants (of the MARIA variety) resulted in a 13.79 % increase in leaf number and a 15.83 % increase in plant height compared to uncoated TSP. This research underscores the pivotal role of advanced coating fertilizers in fostering sustainable and efficient agricultural practices, thereby making a substantial contribution to the advancement of innovative agrochemical solutions.

Bio-synthesized TiO2 nanoparticles and the aqueous binder-based anode derived thereof for lithium-ion cells.

Titanium dioxide nanoparticles (TiO2-NPs) are a promising anode material for Lithium-ion batteries (LIBs) due to their good rate capability, low cost, non-toxicity, excellent structural stability, extended cycle life, and low volumetric change (∼4%) during the Li+insertion/de-insertion process. In the present paper, anatase TiO2-NPs with an average particle size of ~ 12nm were synthesized via a green synthesis route using Beta vulgaris (Beetroot) extract, and the synthesized TiO2-NPs were evaluated as anode material in LIBs. Furthermore, we employed an aqueous binder (1:1 mixture of carboxy methyl cellulose and styrene butadiene) for electrode processing, making the process cost-effective and environmentally friendly. The results revealed that the Li/TiO2 half-cells delivered an initial discharge capacity of 209.7 mAh g-1 and exhibited superior rate capability (149 mAh g-1 at 20 C) and cycling performances. Even at the 5C rate, the material retained a capacity of 82.2% at the end of 100 cycles. The synthesis route of TiO2-NPs and the aqueous binder-based electrode processing described in the present work are facile, green, and low-cost and are thus practically beneficial for producing low-cost and high-performance anodes for advanced LIBs.

Effect of glycosylation on soy protein isolate–sodium carboxymethyl cellulose conjugates heat-induced gels and their applications as carriers of riboflavin

The objective of this study was to improve the rheological properties and riboflavin delivery ability of soy protein isolate (SPI) gels by incorporating sodium carboxymethyl cellulose (CMC) through glycosylation. The investigation focused on the structural and gel properties of SPI–CMC conjugates at different Maillard reaction times (30, 60, 90, 120, and 150 min). The results showed that the degree of grafting initially increased and then decreased as the Maillard reaction times increased, reaching its peak at 90 min (25.52%). The changes in the structure and conformation of the SPI–CMC conjugates were verified by Fourier transform infrared spectroscopy and surface hydrophobicity. An appropriate Maillard reaction reduced the content of highly ordered α-helix and β-sheet while increasing the content of disordered random coil and β-turn. This secondary structural change led to protein unfolding, exposure of surface hydrophobic groups, and orderly aggregation, forming a dense cross-linked gel network. When the Maillard reaction times increased, especially for 90 min, the gel strength and water-holding capacity of the SPI–CMC conjugate gels were significantly increased, along with a denser microstructure. Compared with the SPI and SPI–CMC mixture, SPI–CMC conjugate gels with 60 and 90 min reaction times exhibited notably increased viscosity and storage modulus (G′), as well as better structural recovery characteristics. The above physicochemical property improvements markedly enhanced the riboflavin encapsulation efficiency and riboflavin delivery ability of SPI–CMC conjugate gels, improving the ability to protect riboflavin from photodegradation and slowly releasing riboflavin in the simulated intestinal environment. Hence, SPI–CMC conjugate gels have significant potential for the delivery of nutrients.

Preparation and investigation of the structural and mechanical properties of biodegradable gelatin- based films

Biodegradable gelatin-based films have been obtained in the presence of carboxymethylcellulose (CMC) additives intended for use as packaging of food products and drug carriers. By methods of scanning electron microscopy and measurement of film roughness, it was found that films obtained from a mixture of CMC and gelatin have the greatest roughness. It is shown that the introduction of CMC into the composition of gelatin films leads to a sharp decrease in the strength and modulus of elasticity of the films, however, the deformation has maximum values at a mass ratio of CMC / gelatin equal to 0.7. This is explained by the formation of associates due to H-bonds and electrostatic interactions between functional groups of gelatin proteins and polysaccharide macromolecules, stabilized by hydrophobic interactions between their nonpolar sites. The barrier properties of films based on CMC and gelatin have been studied. It is shown that CMC-based films have the highest air permeability and the lowest water resistance, which is due to the texture of the film material. Based on IR spectroscopy data, it was found that films obtained from a mixture of CMC and gelatin are the most stable. Glycerin was used to regulate the deformation of the films.

Preparation and Evaluation of Antimicrobial Property and Anti-inflammatory Activity of Fenugreek Gel Against Oral Microbes: An Invitro Study.

Aim Periodontal dressings play a crucial role in periodontal surgery and dental procedures. These dressings have several functions and benefits, similar to surgical wound dressings used in other surgical contexts.Periodontal dressings protect the surgical site and control bleeding in the oral cavity as they exert pressure on tissue and blood vessels. By protecting the wound and stabilizing the tissues, periodontal dressings create an environment that encourages proper and faster healing. Recently, the use of periodontal pack has reported various postoperative discomfort to the patients. This led to the development of an interest in considering fenugreek as an alternative to periodontal dressing as it possesses variousantidiabetic and hypolipidemic effects. Thus, fenugreek can be used as an alternative to periodontal dressing.The study aimed to prepare and evaluate the antimicrobial nature of fenugreek gel in oral microbes and the anti-inflammatory properties of gel with protein coagulation in egg albumin. Materials and methods The fenugreek gel preparation was done by grinding 100 g offenugreek seeds into a powder and adding 100 ml of distilled water to the powder and then heatingthemixture at 70°C for 30 minutes. Five milliliters of the fenugreek concentrate were added to an equal mixture of carboxymethyl cellulose and Carbopol which was mixed thoroughly to form a gel.Theantimicrobial nature of fenugreek has been evaluated in various organisms such asStreptococcus mutans, Lactobacillus, Enterococcus faecalis, and Candida albicanswhereasthe anti-inflammatory property was evaluated by protein coagulation method in egg albumin. Results The results stated that the fenugreek gel at a concentration of 100 µg/ml showed a greater zone of inhibition (5.39 ± 0.05) compared with doxycycline (1.1 ± 0.08) for a high antimicrobial potential against all oral microbes. The anti-inflammatory activity of the gel by protein coagulation method in egg albumin showed greater inhibition (67.15±1.36) at 100 µg/ml of fenugreek extract when compared with aspirin (64.43±2.93).Paired t-test was done for boththe properties and the p-valuewas less than 0.5 stating that the difference between the groups was statistically significant. Conclusion The present study showed that the fenugreek gel possesseshigher antimicrobial and anti-inflammatory propertieswhen compared with doxycycline and aspirin, respectively. Hence, fenugreek gel can be used as analternative periodontal dressing to reduce postoperative inflammation.

Mathematical Modeling of Pseudoplastic Nanofluid Natural Convection in a Cavity with a Heat-Generating Unit and Solid Finned Heat Sink

The power-law nanofluid natural convection in a chamber with a thermally generating unit and a solid ribbed structure has been studied in this work. A mixture of carboxymethylcellulose with water and copper nanoparticles is a working fluid illustrating pseudoplastic properties. The effective properties of the nanoliquid have been described by experimental correlations reflecting the temperature effect. The governing equations have been formulated on the basis of the conservation laws of mass, momentum and energy employing non-primitive parameters such as stream function and vorticity. The defined boundary value problem has been worked out by the finite difference technique using an independently developed calculation system. The Rayleigh number is fixed for analysis (Ra = 105). The paper analyzes the influence of the nanoparticles volume fraction, an increase in which reduces the temperature in the case of the one edge presence. An analysis of the rib height has shown that its growth leads to a weakening of the convective heat transfer, but at the same time, the source temperature also decreases. Increasing the number of fins from 1 to 3 also helps to reduce the average temperature of the heat-generated element by 15%.

A facile strategy to fabricate high-barrier, water- and oil-repellent paper with carboxymethyl cellulose/collagen fiber/modified polyvinyl alcohol

Due to the increasingly serious environmental and human health hazards brought by traditional food packaging materials, paper-based packaging materials have become increasingly popular among consumers in recent years. Currently, the fabrication of fluorine-free degradable water- and oil-repellent paper using low-cost bio-based polymers by a simple method is a hot subject in the field of food packaging. In this work, we used carboxymethyl cellulose (CMC), collagen fiber (CF), and modified polyvinyl alcohol (MPVA) to create coatings that were impervious to water and oil. The homogeneous mixture of CMC and CF generated electrostatic adsorption to impart excellent oil repellency to the paper. PVA was chemically modified by sodium tetraborate decahydrate, and the MPVA coating imparted excellent water-repellent properties to the paper. Finally, the water- and oil-proof paper showed excellent water repellency (Cobb value: 1.12 g/m2), oil repellency (kit rating: 12/12), low air permeability (0.3 μm/Pa·s), and stronger mechanical properties (4.19 kN/m). This non-fluorinated degradable water- and oil-repellent paper with high barrier properties prepared by a convenient method is expected to be in widespread use in the food packaging field.

Polymer‐Lipid Matrices based on Carboxymethyl Cellulose/Solagum and Liposomes for Controlled Release of Folic Acid

AbstractLiposome‐encapsulated folic acid is incorporated into the films made from sodium carboxymethyl cellulose (CMC) (2 mas%) and a mixture of CMC and solagum (9:1 w/w) using the film‐forming cast solution method. Histidine is used to increase solubility for folic acid in liposomes (1–5 mg mL−1), and propylene glycol is used as a film plasticizer (2.6 mas%). The obtained films (50–60 µm tick) containing 3.12–20.19 mg of folic acid per gram of film are envisaged to be used as patches for transdermal delivery of folic acid. Therefore, some physical, mechanical, release and structural attributes of the films are scrutinized. Folic acid gives yellow color to the films and contributes to stronger chemical bonds which result in improved strength of the film. Liposomes prolong the release of folic acid from films to 24 h without adverse effects on mechanical properties of the films, but degrade homogeneity of the films, which can be ascribed to its agglomeration within the film matrix as revealed by atomic force microscopy. According to the release at pH 5.5, the film formulation based on a blend of CMC and solagum containing 3 mg mL−1 liposome‐encapsulated folic acid is recommended.Practical Application: Folic acid is effective in reducing oxidative stress levels in the skin and neutralizing the harmful free radicals and is also essential for various metabolic reactions in the body. However, the limited solubility of folic acid linked with its poor absorption in an organism, low storage stability, short half‐life upon oral consumption, specific food preferences of some people, extensive liver metabolism, and pregnancy‐induced vomiting point to a large potential in transdermal usage of folic acid. This has motivated us to design new multicomponent polymer‐lipid systems as an alternative solution to overcome some of these drawbacks. The results obtained for these multicomponent films pointed to their potential for prolonged release of folic acid to 24 h, which can also be useful for scientists interested in encapsulating similar poorly soluble compounds in CMC patches. The finding can be also valuable information for pharmaceutical manufacturers and scientists worldwide.

Effect of sonication to the stability properties of carboxymethyl cellulose/uncaria gambir extract water-based lubricant

This study examined the effect of sonication on FTIR and stability at various temperatures in water-based lubricants with a mixture of Carboxymethyl Cellulose (1wt%) and Uncaria Gambir extract (1wt% and 2wt%). The sample was prepared by mixing the two materials into distilled water using a magnetic stirrer and sonicator with time variations of 5 and 10 minutes. Before mixing, the Uncaria Gambir extract solution with water is first centrifuged to remove the dregs in the Uncaria Gambir extract powder. Stability was carried out in an open room (28oC), drying oven (50oC), and refrigerator (5oC). The stability test results showed that the mixture of Carboxymethyl Cellulose and Uncaria Gambir had good stability at all temperatures after sonication for a short duration. The longer sonication duration could fuse the fibrils of Carboxymethyl Cellulose, leading to increasing particle size. FTIR results also show that there is no chemical reaction that occurs. After adding the gambier, there was a new peak at wave 800-1300 cm-1, corresponding to the gambier. The results of this study indicate that the Carboxymethyl Cellulose and Uncaria Gambir solution can be a potential lubricant additive. The Carboxymethyl Cellulose can be a viscosity modifier, while Uncaria Gambir extract for corrosion inhibitor.

Preparation and Hydrogelling Performances of a New Drilling Fluid Filtrate Reducer from Plant Press Slag.

Plant press slag (PPS) containing abundant cellulose and starch is a byproduct in the deep processing of fruits, cereals, and tuberous crops products. PPS can be modified by using caustic soda and chloroacetic acid to obtain an inexpensive and environmentally friendly filtrate reducer of drilling fluids. The optimum mass ratio of mNaOH:mMCA:mPPS is 1:1:2, the optimum etherification temperature is 75 °C, and the obtained product is a natural mixture of carboxymethyl cellulose and carboxymethyl starch (CMCS). PPS and CMCS are characterized by using X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric, X-ray photoelectron spectroscopy, and elemental analysis. The filtration loss performance of CMCS is stable before and after hot-rolling aging at 120 °C in 4.00% NaCl and saturated NaCl brine base slurry. The minimum filtration loss value of CMCS is 5.28 mL/30 min at the dosage of 1.50%. Compared with the commercial filtrate reducers with a single component, i.e., carboxymethyl starch (CMS) and low viscosity sodium carboxymethyl cellulose (LV-CMC), CMCS have a better tolerance to high temperature of 120 °C and high concentration of NaCl. The filtration loss performance of low-cost CMCS can reach the standards of LV-CMC and CMS of the specification of water-based drilling fluid materials in petroleum industry.

Simultaneous production of cellulase and amylase by Aspergillus fumigatus IB-A1

Utilization of agricultural wastes for production of useful metabolites requires hydrolysis using both cellulase and amylase enzymes. We isolated Aspergillus fumigatus IB-A1 and evaluated its ability to simultaneously produce both cellulase and amylase. Although the isolate could produce both cellulase and amylase from either soluble starch or carboxymethyl cellulose, amylase activity was higher with soluble starch while cellulase activity was higher when carboxymethyl cellulose was used as the sole carbon source. With a mixture of carboxymethyl cellulose and soluble starch, both the amylase and cellulase activities increased with increase in the ratio of soluble starch. The optima ratio of carboxymethyl cellulose to soluble starch for cellulase and amylase activities were 0.7:0.3, and 0.4 to 0.6 respectively. For practical application, the optimum ratio of carboxymethyl cellulose to soluble starch in the production medium depends on the relative composition of cellulose and starch in the substrate to be hydrolyzed. The isolate was also able to efficiently produce both amylase and cellulase from cassava peel. With 10 g/L cassava peel, the cellulase and amylase activities were 6.122± 0.320 U/ml/min and 4.342± 0.210 U/ml/min respectively. When the cells were immobilized on loofa sponge and subjected to alternating air phase- liquid phase culture, cellulase and amylase production from cassava peel increased to 8.106± 0.620 U/ml/min and 5.206± 1.24 U/ml/min respectively. The optimum ratio of the air phase to the liquid phase was 3 hours of air phase to 21 hours of liquid phase.

Physical Modification of Hybrid Hydrogels to Fabricate Full-Scale Construct Using Three-Dimensional Bio-Printing Process.

Bioprinting for regenerative medicine has been gaining a lot of popularity in today's world. Despite being one of the rigorously studied fields, there are still several challenges yet to be solved. Geometric fidelity and mechanical complexities stand as roadblocks when it comes to the printability of the customized constructs. Exploring the rheological properties of the compositions helps us understand the physical and mechanical properties of the biomaterials which are closely tied to the printability of the filament and eventually, geometric fidelity of the constructs. To ensure the structural integrity of the constructs, viscosity enhancers such as carboxymethyl cellulose (CMC) and crosslinkers like CaCl2 and CaSO4 were used. These crosslinkers can be used before (precrosslinking) and after (postcrosslinking) the extrusion of considered compositions to investigate and compare the outcome. To do this, mixtures of CMC (viscosity enhancer), Alginate, and CaCl2 and CaSO4 (crosslinkers) were prepared at various concentrations maintaining minimum solid content (≤8%). Each composition was subjected to a set of rheological tests like flow curve for shear thinning behavior, three points thixotropic for recovery rate, and amplitude test for gelation point. Various geometric fidelity identification tests were conducted and correlated with their physical properties. Some compositions were used to fabricate large-scale constructs (in cm-scale) to demonstrate their capability. This research is a thorough investigation of compositions when they are introduced to crosslinkers and viscosity enhancers which can be crucial for the 3D printing world.

Efficient stabilization of soil, sand, and clay by a polymer network of biomass-derived chitosan and carboxymethyl cellulose

Biomass-derived polymers are being increasingly utilized as eco-friendly functional materials in fields ranging from medicine and food to agriculture and environmental engineering. In this report, we developed a novel efficient method for improvement of soil materials based on in situ gelation of a polyion complex formed by biomass-derived carboxymethyl cellulose (CMC) and chitosan (CS). Self-organized network of polymer films and microfibers assembled via electrostatic interactions between oppositely-charged polyions interconnects particles of soil material and imparts the resulted composite with a considerable mechanical strength. Treatment of soil even with a high water content (ca. 30%) by a mixture of CMC and CS at m(CMC + CS)/m(soil) ratio of ca. 1% is sufficient to gain up to 150 kPa compression strength that further increases up to ca. 1 MPa after drying. Similar reinforcement effect by CMC-CS complex was observed for sand, and much higher yield strengths were measured for clay. Mechanical properties of soil materials strengthened by CMC-CS complex depended on structure and stability of CMC-CS polyion network and controlled by the polymerization degrees of macromolecules and the charge ratio between them. Being composed entirely of biomass-derived polymers, the proposed soil treatment system is particularly attractive due to environmental friendliness and sustainability and it can be utilized not only for the soil improvement but also for the construction of functional platforms for soil pollution control and remediation.

Biopolymer Hydrogel Scaffolds Containing Doxorubicin as A Localized Drug Delivery System for Inhibiting Lung Cancer Cell Proliferation.

A hydrogel scaffold is a localized drug delivery system that can maintain the therapeutic level of drug concentration at the tumor site. In this study, the biopolymer hydrogel scaffold encapsulating doxorubicin was fabricated from gelatin, sodium carboxymethyl cellulose, and gelatin/sodium carboxymethyl cellulose mixture using a lyophilization technique. The effects of a crosslinker on scaffold morphology and pore size were determined using scanning electron microscopy. The encapsulation efficiency and the release profile of doxorubicin from the hydrogel scaffolds were determined using UV-Vis spectrophotometry. The anti-proliferative effect of the scaffolds against the lung cancer cell line was investigated using an MTT assay. The results showed that scaffolds made from different types of natural polymer had different pore configurations and pore sizes. All scaffolds had high encapsulation efficiency and drug-controlled release profiles. The viability and proliferation of A549 cells, treated with gelatin, gelatin/SCMC, and SCMC scaffolds containing doxorubicin significantly decreased compared with control. These hydrogel scaffolds might provide a promising approach for developing a superior localized drug delivery system to kill lung cancer cells.

Elastase-triggered H2S delivery from polymer hydrogels.

We report an elastase-responsive, H2S-releasing hydrogel prepared by covalently crosslinking a mixture of carboxymethylcellulose and poly(ethylene glycol) with an elastase-degradable peptide functionalized with an H2S-releasing S-aroylthiooxime (SATO) unit. Addition of elastase triggered a gel-to-sol transition, which exposed SATOs, leading to more and longer H2S release compared to untriggered gels.

Green encapsulation of LDH(Zn/Al)-5-Fu with carboxymethyl cellulose biopolymer; new nanovehicle for oral colorectal cancer treatment

Due to the decrease of the drugs side effects in controlled drug delivery systems, today's many research has been focused on designing the new controlled drug delivery systems. The main aim of the present work was the improving of the layered double hydroxide (LDH) properties as a drug delivery system through the encapsulation with carboxymethyl cellulose (CMC). In the first section, 5-fluorouracil (5-Fu) as a colon anticancer drug was loaded in LDH(Zn/Al) (about 87%). The FT-IR, SEM, and XRD analysis were used to probe the successful synthesis of LDH(Zn/Al) and 5-Fu loading in it. In the following, the nanohybrid encapsulated with CMC, through the crosslinking of the LDH(Zn/Al)-5-Fu and CMC mixture with Fe(III) as a physical crosslinker and CMC/LDH(Zn/Al)-5-Fu hydrogel beads were formed. From comparing of the 5-Fu release from the LDH(Zn/Al)-5-Fu and CMC/LDH(Zn/Al)-5-Fu hydrogel beads, it was found that the use of CMC as a capsule induce the controlled and sustained drug release behavior to the system. MTT assay approved the biocompatibility of the CMC/LDH(Zn/Al)-5-Fu hydrogel beads. With considering the swelling, drug loading, drug-releasing, and MTT assay results, the prepared CMC/LDH(Zn/Al)-5-Fu hydrogel beads system could be proposed as a potentially safe oral delivery system for colon cancer therapy.

Rheological and dielectric behavior of milk/sodium carboxymethylcellulose mixtures at various temperatures

Rheological and dielectric behavior of milk/sodium carboxymethylcellulose (Na-CMC) mixtures with 0–10 g/L Na-CMC were investigated from 15 °C to 55 °C. Shear viscosity and viscoelastic behavior of milk/Na-CMC mixtures are mainly controlled by Na-CMC. Raising temperature has an obviously influence on viscoelastic behavior of mixtures. Meaning, the interchain hydrogen bond interaction among Na-CMC chains and the hydrogen bond interaction between Na-CMC chains and water molecules change with temperature. At 55 °C, the viscoelastic behavior of mixture with 2.5 g/L Na-CMC is different from that of the others. That indicates temperature has a larger impact on chain conformation of Na-CMC at the mixtures containing lower Na-CMC concentration. The dielectric spectra show one relaxation caused by loosely bound counterions. With increasing temperature and Na-CMC concentration, the changes of relaxation time τ and dielectric increment ∆ε are critically relevant to the numbers of bound counterions and chain conformation of Na-CMC. The contribution of Na-CMC to the dc conductivity of mixtures notably changes at 45 °C. It reveals the free ion numbers and viscosity of bulk phase obviously changes at 45 °C. The results reveal the stability of mixtures reduce with increasing temperature.

Structural heteropolysaccharides as air-tight sealants of the human pleura.

Pulmonary "air leaks," typically the result of pleural injury caused by lung surgery or chest trauma, result in the accumulation of air in the pleural space (pneumothorax). Air leaks are a major source of morbidity and prolonged hospitalization after pulmonary surgery. Previous work has demonstrated structural heteropolysaccharide (pectin) binding to the mouse pleural glycocalyx. The similar lectin-binding characteristics and ultrastructural features of the human and mouse pleural glycocalyx suggested the potential application of these polymers in humans. To investigate the utility of pectin-based polymers, we developed a simulacrum using freshly obtained human pleura. Pressure-decay leak testing was performed with an inflation maneuver that involved a 3 s ramp to a 3 s plateau pressure; the inflation was completely abrogated after needle perforation of the pleura. Using nonbiologic materials, pressure-decay leak testing demonstrated an exponential decay with a plateau phase in materials with a Young's modulus less than 5. In human pleural testing, the simulacrum was used to test the sealant function of four mixtures of pectin-based polymers. A 50% high-methoxyl pectin and 50% carboxymethylcellulose mixture demonstrated no sealant failures at transpleural pressures of 60 cmH2 O. In contrast, pectin mixtures containing 50% low-methoxyl pectin, 50% amidated low-methoxyl pectins, or 100% carboxymethylcellulose demonstrated frequent sealant failures at transpleural pressures of 40-50 cmH2 O (p < 0.001). Inhibition of sealant adhesion with enzyme treatment, dessication and 4°C cooling suggested an adhesion mechanism dependent upon polysaccharide interpenetration. We conclude that pectin-based heteropolysaccharides are a promising air-tight sealant of human pleural injuries. © 2018 Wiley Periodicals, Inc. J. Biomed. Mater. Res. Part B, 2018. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 799-806, 2019.