Carboxymethylcellulose Group Research Articles

Co-immobilization of lipase and β-galactosidase in gelatin-carboxymethyl cellulose blend films used as an active packaging component

β-Galactosidase and lipase were co-immobilized in polymeric blends of gelatin (GEL) and carboxymethyl cellulose (CMC) synthesized with different ratios of GEL/CMC: A (0GEL:100CMC), B (25GEL:75CMC), C (50GEL:50CMC), D (75GEL:25CMC), E (100GEL:0CMC). The films obtained good electrostatic interaction and a regular and uniform structure. The addition of CMC increased the mechanical resistance of the films, the tensile strength being 35.04 ± 0.10 MPa for A (0GEL:100CMC) films and 19.17 ± 2.44 MPa for E (100GEL:0CMC) films. Thermogravimetry (TG) showed that the addition of the enzyme decreases the thermal stability of the films. Film B (25GEL:75CMC) showed greater affinity with the added enzymes and greater thermal stability, in addition to increasing the crystallinity by up to 5.8 % and forming more transparent films. CMC was the most hydrophilic polymer, with higher moisture content (17.35 ± 1.73 %) and PVA (0.398 ± 0.047 g.mm/h.m2.kPa), higher still after the addition of enzyme (22.91 ± 1.06 % and 1.136 ± 0.087 g.mm/h.m2.kPa). The enzymes showed greater interaction with the bulky groups of CMC and the film with the highest concentration of this polymer was the one that presented the best hydrolysis rate of lactose and triglycerides, enabling the production of films.

Solubilized β-Glucan Supplementation in C57BL/6J Mice Dams Augments Neurodevelopment and Cognition in the Offspring Driven by Gut Microbiome Remodeling.

A maternal diet rich in dietary fiber, such as β-glucan, plays a crucial role in the offspring's acquisition of gut microbiota and the subsequent shaping of its microbiome profile and metabolome. This in turn has been shown to aid in neurodevelopmental processes, including early microglial maturation and immunomodulation via metabolites like short chain fatty acids (SCFAs). This study aimed to investigate the effects of oat β-glucan supplementation, solubilized by citric acid hydrolysis, from gestation to adulthood. Female C57BL/6J mice were orally supplemented with soluble oat β-glucan (ObG) or carboxymethyl cellulose (CMC) via drinking water at 200 mg/kg body weight during breeding while the control group received 50 mg/kg body weight of carboxymethyl cellulose. ObG supplementation increased butyrate production in the guts of both dams and 4-week-old pups, attributing to alterations in the gut microbiota profile. One-week-old pups from the ObG group showed increased neurodevelopmental markers similar to four-week-old pups that also exhibited alterations in serum markers of metabolism and anti-inflammatory cytokines. Notably, at 8 weeks, ObG-supplemented pups exhibited the highest levels of spatial memory and cognition compared to the control and CMC groups. These findings suggest a potential enhancement of neonatal neurodevelopment via shaping of early-life gut microbiome profile, and the subsequent increased later-life cognitive function.

Inulin protects against the harmful effects of dietary emulsifiers on mice gut microbiome.

The prevalence of inflammatory bowel diseases is increasing, especially in developing countries, with adoption of Western-style diet. This study aimed to investigate the effects of two emulsifiers including lecithin and carboxymethyl cellulose (CMC) on the gut microbiota, intestinal inflammation and the potential of inulin as a means to protect against the harmful effects of emulsifiers. In this study, male C57Bl/6 mice were divided into five groups (n:6/group) (control, CMC, lecithin, CMC+inulin, and lecithin+inulin). Lecithin and CMC were diluted in drinking water (1% w/v) and inulin was administered daily at 5 g/kg for 12 weeks. Histological examination of the ileum and colon, serum IL-10, IL-6, and fecal lipocalin-2 levels were analyzed. 16S rRNA gene V3-V4 region amplicon sequencing was performed on stool samples. In the CMC and lecithin groups, shortening of the villus and a decrease in goblet cells were observed in the ileum and colon, whereas inulin reversed this effect. The lipocalin level, which was 9.7 ±3.29 ng in the CMC group, decreased to 4.1 ±2.98 ng with the administration of inulin. Bifidobacteria and Akkermansia were lower in the CMC group than the control, while they were higher in the CMC+inulin group. In conclusion, emulsifiers affect intestinal health negatively by disrupting the epithelial integrity and altering the composition of the microbiota. Inulin is protective on their harmful effects. In addition, it was found that CMC was more detrimental to microbiota composition than lecithin.

OSDI Score Comparison between Sodium Hyaluronate, Carboxymethylcellulose and Polyvinylpirrolidone for Dry Eye in Medical Student during Online Learning

Abstract
 Introduction & Objectives : Online learning during COVID pandemic increase medical students’ screen time. Prolonged screen time is known as a risk factor for dry eye. Health problems during online learning such as those induced by dry eye could affect students’ academic performance. This study aim to find the best solution for dry eye in medical student during online learning by comparing three artificial tears eye drops, namely sodium hyaluronate, carboxymethylcellulose and polyvinylpirrolidone.
 Methods : This is an experimental study with 48 respondents divided into three treatment groups : sodium hyaluronate (SH), carboxymethylcellulose (CMC) and polyvinylpirrolidone (PVP). Each group consists of 16 respondents. Each respondents use their eyedrops six times daily in both eyes for two weeks. This study use Ocular Surface Disease Index questionnaire to evaluate dry eye. Data were analyzed using SPSS software, with p<0,05 is considered significant.
 Results : In SH group, mean OSDI score before treatment were 37,52 and after treatment 13,84 (p=0,001). In CMC group, mean OSDI score before treatment were 35,28 and after treatment 12,54 (p=0,000). In PVP group mean OSDI score before treatment were 38,17 and after treatment 13,15 (p=0,000). No significant differences of OSDI score was found between groups before treatment and after treatment (p=0,237).
 Conclusion : Sodium hyaluronate, carboxymethylcellulose and polyvinylpirrolidone eye drops could similiary improve dry eye symptoms significantly as measured by OSDI score in medical students during online learning.

Effect of carboxymethyl cellulose, icodextrin and hyaluronic acid solutions on postoperative intraabdominal adhesion formation in rabbits and the role of cytokines in intraabdominal adhesion formation

In this study, the aim was to investigate the effects of 1% CMC, 4% ICO and 0.4% HA solutions in preventing postoperative IAs and their contribution to peritoneal wound healing, as well as the relationship of cytokines with the formation of postoperative IAs in rabbits. The material of the study consisted of 32 healthy rabbits. Rabbits underwent median laparotomy following general anesthesia. Serosal abraded was created at the antimesenteric border of the cecum. Next, a 3 × 2 cm peritoneum was excised on the right abdominal wall and the defect was closed using with a 2/0 silk suture. The rabbits were randomly assigned to either of the following four treatment groups: CNT (0.9% NaCl), ICO (4% icodextrin), HA (0.4% hyaluronic acid) and CMC (1% carboxymethyl cellulose). Both cecum and peritoneal surfaces were treated with 20 ml each of treatment solutions. On the 7th postoperative day, the rabbits were euthanized with a lethal dose of sodium pentobarbital and the degree of adhesion was evaluated. Samples taken from the peritoneal defect were examined histopathologically and tissue hydroxyproline levels were measured. Serum TNF-α, IL-1 and IL-6 levels were measured from blood samples taken before the surgery and at 1, 6, 24 and 48 hours after the surgery. It was observed that the adhesion grade in the HA group (p < 0.05) and CMC group (p < 0.01) was significantly lower than the control group. Although peritoneal tissue hydroxyproline levels were lower in the other groups compared to the control group, they were not statistically significant (p > 0.05). In rabbits with adhesion formation, it was determined that TNF-α levels increased at the 6th postoperative hour (p < 0.05), and IL-6 levels increased at the 6th, 24th and 48th postoperative hours (p < 0.001) compared to preoperative. In this study, treating tissues with 0.4% HA and 1% CMC solutions suppressed peritoneal inflammation, and this resulted in an increase in the levels of proinflammatory cytokines TNF-α and IL-6. It has been determined that the application of these solutions reduces postoperative adhesion formation. It was concluded that TNF-α and especially IL-6, which are proinflammatory cytokines, can be a non-invasive biomarker in determining postoperative IA formation and evaluating the adhesive process.

Pd@HKUST-1@Cu(II)/CMC composite bead as an efficient synergistic bimetallic catalyst for Sonogashira cross-coupling reactions

We fabricated an efficient Pd@HKUST-1@Cu(II)/CMC composite bead catalyst through an innovative strategy based on the unique properties of metal-organic frameworks (MOFs) and carboxymethylcellulose (CMC). In this strategy, HKUST-1 MOFs were grown in-situ on the surface of micrometer-sized Cu-based CMC beads (Cu(II)/CMC), then Pd(II) ions were incorporated into the pores of the MOF and further be partially reduced to Pd(0) NPs, which is an active species for oxidative addition with aryl halides in Sonogashira reactions. The micron-sized Cu(II)/CMC beads were formed through inter/intramolecularly crosslinking facilitated by Cu(II) ions, which was achieved by the metathesis of Cu(II) with numerous carboxylic groups of CMC. Such Cu(II)/CMC bead offers many Cu(II) ions as interaction sites for in-situ nucleation and growth of HKUST-1 MOFs. The architecture and composition of the prepared Pd@HKUST-1@Cu(II)/CMC composite were fully verified by various techniques such as FTIR, XRD, TGA, BET, XPS, SEM, TEM, EDX, and elemental mapping analysis. This novel composite bead was applied as an efficient and reusable heterogeneous Pd/Cu bimetallic catalyst for Sonogashira reactions, decarbonylative Sonogashira reaction, and Sonogashira cyclization tandem reactions. The catalyst is readily isolated by simple filtration, and can be reused for five consecutive runs with retaining its activity and structural integrity.

Comparing the efficacy of sodium hyaluronate eye drops and carboxymethylcellulose eye drops in treating mild to moderate dry eye disease.

Aim of this study was to compare the efficacy of sodium hyaluronate (SH) and carboxymethyl cellulose (CMC) eye drops in treating mild to moderate dry eye disease in terms of relief of symptoms, mean change in tear film breakup time, Schirmer's test, and impression cytology of conjunctiva from baseline. An observational study was carried out during a 2-year period in our tertiary referral hospital. The study consisted of 60 patients randomly allotted to two groups to receive SH and CMC eye drops for an 8-week period. Ocular surface disease index, tear film breakup time, and Schirmer's test were performed at baseline visit and 4 and 8 weeks of treatment, and impression cytology of conjunctiva was performed at baseline and 8 weeks. Significant improvement in patient symptoms, tear film breakup time, and Schirmer's test from baseline was seen in both SH and CMC groups at 8 weeks posttreatment, whereas impression cytology of conjunctiva in both groups did not show significant improvement at 8 weeks of treatment. Data analysis using unpaired t-test showed comparable results. Both CMC and SH demonstrated equal efficacy in treating mild to moderate dry eye disease.

One-Step Low Temperature Synthesis of CeO2 Nanoparticles Stabilized by Carboxymethylcellulose.

An elegant method of one-pot reaction at room temperature for the synthesis of nanocomposites consisting of cerium containing nanoparticles stabilized by carboxymethyl cellulose (CMC) macromolecules was introduced. The characterization of the nanocomposites was carried out with a combination of microscopy, XRD, and IR spectroscopy analysis. The type of crystal structure of inorganic nanoparticles corresponding to CeO2 was determined and the mechanism of nanoparticle formation was suggested. It was demonstrated that the size and shape of the nanoparticles in the resulting nanocomposites does not depend on the ratio of the initial reagents. Spherical particles with a mean diameter 2-3 nm of were obtained in different reaction mixtures with a mass fraction of cerium from 6.4 to 14.1%. The scheme of the dual stabilization of CeO2 nanoparticles with carboxylate and hydroxyl groups of CMC was proposed. These findings demonstrate that the suggested easily reproducible technique is promising for the large-scale development of nanoceria-containing materials.

Aggregation and Growth Mechanism of Ovalbumin and Sodium Carboxymethylcellulose Colloidal Particles under Thermal Induction.

Ovalbumin (OVA)/sodium carboxymethylcellulose (CMC) colloidal particles were prepared with different compactness and morphologies by regulating the interaction between proteins and polysaccharides during heating. Electrostatic interactions between the amine groups of OVA (-NH3+) and carboxyl groups of CMC (-COO-) enhanced complex formation. The protein conformation change benefited the hydrophobic interaction between the particles. Proteins in colloidal particles were unfolded/folded under thermal induction to form aggregates having more β-sheet structures. When the OVA/CMC ratio was 1:2, the initially loosely connected OVA/CMC aggregation changed into a uniform sphere between 25 and 90 °C. The mass ratio of OVA to CMC within the final colloidal particle (90 °C) was about 1:1.4. The OVA/CMC particle stability was maintained with hydrogen bonding, hydrophobicity, and disulfide bond. When OVA levels were predominant, OVA and CMC developed an approximately hollow sphere. Moreover, the final colloidal particle composition showed the OVA-to-CMC ratio as 3:1 (w/w). OVA bound into colloidal particle pores to increase compactness. Moreover, OVA and CMC bound to the colloidal particle while the particle shrank, thereby increasing the compactness of colloidal particles. There was a significant decrease in ABTS•+ scavenging activity of curcumin compared with that of the particles with a ratio of 1:2. Thus, the rational adjustment of the structure of colloidal particles could effectively enhance their functional characteristics, providing a new way for the controlled release of the active ingredients.

Bioengineered Water-Responsive Carboxymethyl Cellulose/Poly(vinyl alcohol) Hydrogel Hybrids for Wound Dressing and Skin Tissue Engineering Applications.

The burden of chronic wounds is growing due to the increasing incidence of trauma, aging, and diabetes, resulting in therapeutic problems and increased medical costs. Thus, this study reports the synthesis and comprehensive characterization of water-responsive hybrid hydrogels based on carboxymethyl cellulose (CMC) and poly(vinyl alcohol) (PVA) using citric acid (CA) as the chemical crosslinking agent, with tunable physicochemical properties suitable to be applied as a wound dressing for soft tissue engineering applications. They were produced through an eco-friendly process under mild conditions. The hydrogels were designed and produced with flexible swelling degree properties through the selection of CMC molecular mass (Mw = 250 and 700 kDa) and degree of functionalization (DS = 0.81), degree of hydrolysis of PVA (DH > 99%, Mw = 84-150 kDa) associated with synthesis parameters, CMC/PVA ratio and extension of chemical crosslinking (CA/CMC:PVA ratio), for building engineered hybrid networks. The results demonstrated that highly absorbent hydrogels were produced with swelling degrees ranging from 100% to 5000%, and gel fraction from 40% to 80%, which significantly depended on the concentration of CA crosslinker and the presence of PVA as the CMC-based network modifier. The characterizations indicated that the crosslinking mechanism was mostly associated with the chemical reaction of CA carboxylic groups with hydroxyl groups of CMC and PVA polymers forming ester bonds, rendering a hybrid polymeric network. These hybrid hydrogels also presented hydrophilicity, permeability, and structural features dependent on the degree of crosslinking and composition. The hydrogels were cytocompatible with in vitro cell viability responses of over 90% towards model cell lines. Hence, it is envisioned that this research provides a simple strategy for producing biocompatible hydrogels with tailored properties as wound dressings for assisting chronic wound healing and skin tissue engineering applications.

Structural and UV-blocking properties of carboxymethyl cellulose sodium/CuO nanocomposite films

Nanoparticles have made a substantial contribution to the field of skincare products with UV filters in preserving human skin from sun damage. The current study aims to create new polymer nanocomposite filters for the efficient block of UV light that results from the stratospheric ozone layer loss. The casting approach was used to add various mass fractions of copper oxide nanoparticles (CuO-NPs) to a solution of carboxymethyl cellulose (CMC). The amorphous nature of CMC was revealed by XRD analysis, with the intensity of the typical peak of virgin polymer in the nanocomposite spectrum decreasing dramatically as the doping amount was increased. The FTIR spectra revealed the functional groups of CMC and the good interaction between the CMC chain and CuO-NPs. Optical experiments revealed that the optical transmittance of pure CMC was over 80%, whereas it dropped to 1% when CuO-NPs content was increased to 8 wt.%. Surprisingly, the inclusion of CuO-NPs considerably improved the UV blocking property of the films extended from the UV region (both UV-A: 320–400 nm and UV-B: 280–320 nm) to the visible region. Optical band gap of CMC decreased sharply with increasing CuO concentration. The tunable optical characteristics can be utilized in UV- blocking filters and various optoelectronics applications.

Dual Stimuli-Responsive Polysaccharide Hydrogels Manufactured by Radiation Technique

This paper describes the results of the radiation-induced crosslinking of polysaccharides modified with hydroxypropyl and carboxymethyl functional groups, hydroxypropylcellulose (HPC) and carboxymethylcellulose (CMC), respectively, without and with poly(ethylene glycol) diacrylate (PEGDA) as a crosslinking agent, to obtain dual stimuli-responsive hydrogels. The gels were characterized in terms of water uptake and gel fraction, parameters that mainly depend on the HPC–CMC compositions, but also on the macromer crosslinker content and the absorbed dose. The swelling of hydrogels is controlled by both the temperature, due to the amphiphilic character of HPC and pH, due to the anionic functional groups of CMC. In spite of a similar degree of substitution in both cellulose derivatives, 1.4 for HPC and 1.2 for CMC, the pH response of hydrogels with an equal content of both polysaccharides is considerably higher—a reduction in swelling of up to 95% with a decrease in the pH to 2 was recorded—than the response to thermal-stimulus—wherein a reduction in swelling of less than 70% with an increasing in temperature to 55 °C was found. These biopolymers-based hydrogels of specific, stimuli-responsive swelling properties are anticipated in applications where a combination of two stimuli is essential and biodegradation may be required.

A Salt-Resistant Sodium Carboxymethyl Cellulose Modified by the Heterogeneous Process of Oleate Amide Quaternary Ammonium Salt.

In this study, hydrophobic quaternary ammonium intermediate was synthesized by epichlorohydrin (ECH) and oleamide propyl dimethyl tertiary amine (PKO). Sodium carboxymethylcellulose (CMC) was chemically modified by introducing a large number of hydrophobic quaternary ammonium branched chains to improve CMC's salt resistance, thickening ability, and solubility. The quaternary ammonium salt structure can partially offset the compression double-layer effect of linear polymers in a low-price salt ion solution, which makes CMC more stretchable and helps it obtain a higher viscosity and greater drag-reduction performance. The experiment was mainly divided into three parts: Firstly, we performed an epichlorohydrin and oleic acid PKO reaction, generating an oleic acid chain quaternary ammonium chlorine atom intermediate. Secondly, the etherification reaction between intermediate -Cl and -OH groups of CMC was completed. Finally, the modified CMC was characterized by IR, SEM, and XPS, and the viscosity and the drag-reduction rate were evaluated. After CMC and the intermediate were reacted at a mass ratio of 9:1.8 at 80 °C for 5 h, the new CMC with enhanced thickening ability, salt resistance, and drag-reduction performance was obtained. We found that the apparent viscosity increased by 11%, the drag reduction rate increased by 3% on average, and the dissolution rate was also significantly accelerated, which was ascribed to the introduction of quaternary ammonium cation. Moreover, the oleic acid amide chain increased the repulsive force of the CMC chain to low-priced metal cations in solution and intermolecular repulsive force, which is beneficial to increase the viscosity, salt resistance, and drag-reduction performance.

Feeding juvenile largemouth bass (Micropterus salmoides) with carboxymethyl cellulose with different viscous: Impacts on nutrient digestibility, growth, and hepatic and gut morphology

A 56-day trial investigated the impact of the dietary inclusion of cellulose with different viscosities on the growth, nutrient digestibility, serum biochemical indices, and the hepatic and gut morphology of largemouth bass juveniles. Four practical diets (42.50% protein and 13.70% lipid) were designed containing 8% microcrystalline cellulose (MC) and carboxymethyl cellulose (CMC) of 2,500, 5,000, and 6,500 mPa s dynamic viscosity [named MC, low-viscosity CMC (Lvs-CMC), medium-viscosity CMC (Mvs-CMC), and high-viscosity CMC (Hvs-CMC) groups, respectively]. Fish of a uniform size (6.0 g) were randomly assigned into 16 cages, with 40 fish per cage. The results showed that the protein and lipid deposition rates, specific growth rate, protein efficiency ratio, and the weight gain rate decreased significantly in the CMC groups compared to the MC group, whereas the feed intake and feed coefficient rate exhibited the opposite trend. Moreover, the intestinal Na+/K+-ATPase, alkaline phosphatase, and lipase activities significantly decreased in the Mvs-CMC and Hvs-CMC groups compared to the MC group, as well as the serum triglyceride, total cholesterol, and high-/low-density lipoprotein contents. The nutrient apparent digestibility significantly decreased in the CMC groups compared to the MC group. The viscerosomatic and intestinal length indices in the CMC groups and the villus height in the Hvs-CMC group were significantly lower than those in the MC group, whereas the number of gut goblet cells and muscular thickness in the Mvs-CMC and Hvs-CMC groups exhibited opposing results. The results also showed that dietary CMC damaged the hepatic and gut morphology and decreased the digestive enzyme activity, nutrient apparent digestibility, and growth of largemouth bass. In summary, viscosity is the main anti-nutritional effect of dietary CMC and soluble non-starch polysaccharides.

Estimation of Platelet Count and Bleeding Time of Mice Treated with Musa paradisiaca var. sapientum (L.) Kuntze Extract.

ObjectiveThe aim of this study was to estimate the platelet count and bleeding time on peripheral blood smear of mice tail wound using Musa paradisiaca var. sapientum (L.) Kuntze (ambonese banana stem extract).DesignRandomized post-test-only control group design.Materials and MethodsTwenty-four male mice (Mus Musculus) were randomly divided into 4 groups. A negative control group was treated with carboxymethyl cellulose (CMC), a positive control group (K+) treated aspirin 100 mg/kg body weight, group P1 treated with aspirin 100 mg/kg body weight and tranexamic acid 50 mg/kg body weight, and group P2 treated with 30% of ambonese banana stem extract (ABSE). The mean and standard deviation data of platelet counts and bleeding time were analyzed by one-way ANOVA statistical software.Results and DiscussionTranexamic acid had no significant effect on platelets count compared to CMC group (p = 0.871), but administration of aspirin resulted in low platelets count significantly (p = 0.003). The platelet counts of ABSE and CMC groups were not significant different (p = 0.937). Aspirin has significantly shown prolonged bleeding time than CMC, tranexamic acid, and ABSE groups. However, there was no difference between the tranexamic acid and ABSE groups (p=0.934). The bleeding time of tranexamic acid and ABSE groups was similar, although the platelet count in the ABSE group was lower than in the CMC group.ConclusionThis study proved that ambonese banana stem extract has a potency to shorten the bleeding time in mice tail wound without interfering to platelet count.

A zwitterionic cellulose-based skin sensor for the real-time monitoring and antibacterial sensing wound dressing

Wound infection can induce inflammation and impede wound healing, being a major challenge in wound care management. A household device that can monitor infection in real time, prevent bacterial, and promote wound healing is highly desired but still rarely investigated. In this work, a novel zwitterionic cellulose-based hydrogel that enables continuously real-time monitoring and pro-healing of infected wound is designed. It is based on interpenetrating polymeric networks, including zwitterionic covalent bond network and physical bond network of carboxymethyl cellulose (CMC) with Ag+via metal-coordination interactions. When used as a sensing dressing, it is developed to exhibit pH-responsive and temperature-responsive properties for assessment of wound infection. Moreover, Ag+ can be released from carboxyl groups of CMC in response to the decrease of pH, killing bacteria and promoting wound healing. This zwitterionic carboxymethyl cellulose-based hydrogel sensor opens new avenues for domestic real-time monitoring and pro-healing of infected wound.

Intestinal flora and immunity response to different viscous diets in juvenile largemouth bass, Micropterus salmoides

An 8-weeks feeding trial was conducted to estimate the effects of different viscous cellulose on the intestinal flora and health in juvenile largemouth bass (Micropterus salmoides). Four isoproteic and isolipidic experimental diets were formulated (crude protein 42.50%, crude lipid 13.70%) to contain 8% cellulose (control group; 5.14 mPa s), 8% low viscous carboxymethyl cellulose (CMC) with 800 mPa s (Lvs-CMC group; 182.15 mPa s), 8% middle viscous CMC with 2000 mPa s (Mvs-CMC group; 320.48 mPa s) and 8% high viscous CMC with 5000 mPa s (Hvs-CMC group; 440.65 mPa s), respectively. The weight gain rate, specific growth rate, protein efficiency ratio, protein and lipid deposition rate in the CMC groups were dramatically lower than those in the control group, while feed conversion rate showed an opposite result. Plasma diamine oxidase activity, endothelin-1 and lipopolysaccharide concentrations in the Mvs-CMC and Hvs-CMC groups were significantly higher than in the control group, accompanied by a significant down-regulation of Occludin, Caludin-1 and Caludin-4. Intestinal glutathione concentration, superoxide dismutase and catalase activities in the CMC groups were significantly lower than in the control group, accompanied by a significant up-regulation of Keap1 and down-regulation of Nrf2. Moreover, CMC diets dramatically down-regulated the expression levels of IL-10 and TGF-β1. Digesta total short chain fatty acid and acetate concentrations in the CMC groups were dramatically higher than in the control group, while butyrate concentration showed an opposite result. The OTU, Sobs, Shannon and Simpson indices of intestinal flora in the CMC groups were dramatically lower than in the control group. Notably, structural analysis showed that dietary CMC dramatically increased the abundance of C. somerae and P. shigelloides, but reduced the abundance of C. colicanis and C. perfringens. In summary, increasing dietary viscosity adversely affects the intestinal flora structure and diversity, increases acetate/butyrate-producing bacterial ratio and the abundance of pathogenic microorganisms, disrupting intestinal flora homeostasis, impairs mucosa barrier function, induces intestinal inflammation and epithelial cell apoptosis in juvenile largemouth bass. Our findings demonstrate that soluble cellulose is more detrimental to intestinal health and growth in juvenile largemouth bass compared to insoluble cellulose, and the adverse effects of soluble cellulose are mainly caused by its viscosity. Importantly, this study demonstrate that viscosity is the main characteristic of non-starch polysaccharides that are detrimental to the intestinal health of fish.

Development of an improved virus plaque assay based on avicel

Avicel is made of a mixture of microcrystalline cellulose (MCC) and carboxymethyl cellulose (CMC), and used for virus plaque assay. The avicel in common use is produced by FMC Biopolymer. Due to the relatively fixed proportion of MCC and CMC, avicel in common use is not suitable for plaque determination experiment of all types of viruses. In this study, we evaluated the effect of avicel made of different proportions of MCC and CMC on virus plaque assay, and developed an improved avicel virus plaque assay featured with simple and convenient operation, good practicability and high stability. To generate avicel overlays with different proportions of MCC and CMC, twelve different 2×avicel solutions were prepared. Their overall viscosity and bottom viscosity were measured to evaluate the ease of operation. The results showed that most of the 2×avicel solutions (except the 4.8% MCC+1.4% CMC and 4.8% MCC+1.0% CMC group) were easy to absorb and prepare nutrient overlap than 2×CMC solution. In order to find the best scheme to detect the titer of porcine epidemic diarrhea virus (PEDV), these avicel overlay solutions with different proportion of MCC and CMC were used as a replacement in the standard plaque assay. By comparing the size, clarity, stability and titer accuracy of virus plaque, we identified that 0.6% MCC and 0.7% CMC was the most preferable composition of avicel overlay for PEDV plaque assay. In conclusion, we developed an improved virus plaque assay based on avicel, which may facilitate the research of virus etiology, antiviral drugs and vaccines.

Inhibition of Gasdermin D-Mediated Pyroptosis Attenuates the Severity of Seizures and Astroglial Damage in Kainic Acid-Induced Epileptic Mice.

Objective: Our study aimed to explore whether gasdermin D (GSDMD)-mediated pyroptosis is involved in the mechanism of kainic acid-induced seizures. Methods: C57BL/6 mice were randomly divided into sham and epilepsy groups. The epilepsy group was intrahippocampally injected with kainic acid to induce status epilepticus (SE), and the sham group was injected with an equal volume of saline. Dimethyl fumarate (DMF) was used as the GSDMD N-terminal fragments (GSDMD-N) inhibitor and suspended in 0.5% sodium carboxymethyl cellulose (CMC) for orally administration. The epilepsy group was divided into SE + CMC and SE + DMF groups. In the SE + DMF group, DMF was orally administered for 1 week before SE induction and was continued until the end of the experiment. An equal volume of CMC was administered to the sham and SE + CMC groups. Recurrent spontaneous seizures (SRSs) were monitored for 21 days after SE. Western blot analysis and immunofluorescent staining was performed. Results: The expression of GSDMD increased at 7–21 days post-SE, and GSDMD-N expression was significantly elevated 7 days after SE in both ipsilateral and contralateral hippocampus. GSDMD-positive cells were co-labeled with astrocytes, but not neurons or microglia. Astroglial damage occurs following status epilepticus (SE). Damaged astrocytes showed typical clasmatodendrosis in the CA1 region containing strong GSDMD expression at 7–21 days post-SE, accompanied by activated microglia. In the SE + DMF group, the expression of GSDMD-N was significantly inhibited compared to that in the SE + CMC group. After administration of DMF, SRSs at 7–21 days after SE were significantly decreased, and the number of clasmatodendritic astrocytes, microglia, and the expression of inflammatory factors such as IL-1β and IL-18 were significantly attenuated. Conclusion: GSDMD-mediated pyroptosis is involved in the mechanism of kainic acid-induced seizures. Our study provides a new potential therapeutic target for seizure control.

Laser sintering of coated polyamide 12: a new way to improve flammability

In this study coatings of kaolin and talc particles were successfully applied on the surface of polyamide 12 powder intended for laser sintering (LS). Microscopic observations revealed that using carboxymethyl cellulose (CMC) as surface modifier for fillers led to a better coverage of polymer grains with a surface coverage between 6 and 16% as a function of filler type and content. Differential scanning calorimetry measurements showed that the addition of talc and kaolin led to an increase in the crystallization temperature of PA12, but at the expense of processability. Process parameters were optimized in order to manufacture LS samples with the different coated powders. Fire behavior assessed by cone calorimetry showed that the use of CMC resulted in a significant decrease in the peak of heat release rate depending on the filler type and content. This behavior can be partially explained by an interaction between CMC, fillers and polymer, with the formation of amide linkage between carboxyl part of CMC and amine end groups of polyamide, resulting in an increase in the complex viscosity of materials.