scholarly journals Characterization of intestinal mucus barrier properties upon exposure to salt

2018 ◽  
Author(s):  
Wang
Keyword(s):  
Barrier Properties ◽  
Intestinal Mucus ◽  
Mucus Barrier

scholarly journals Vibrio cholerae motility in aquatic and mucus-mimicking environments

2021 ◽  
Author(s):  
Marianne Grognot ◽  
Anisha Mittal ◽  
Mattia Amyra Mah'moud ◽  
Katja M Taute
Keyword(s):  
Vibrio Cholerae ◽  
Effective Diffusivity ◽  
Statistical Characterization ◽  
Host Environment ◽  
Severe Diarrhea ◽  
Intestinal Mucus ◽  
Mucus Barrier ◽  
Viscous Solutions ◽  
Speed Fluctuations

Cholera disease is caused by Vibrio cholerae infecting the lining of the small intestine and results in severe diarrhea. V. cholerae's swimming motility is known to play a crucial role in pathogenicity and may aid the bacteria in crossing the intestinal mucus barrier to reach sites of infection, but the exact mechanisms are unknown. The cell can be either pushed or pulled by its single polar flagellum, but there is no consensus on the resulting repertoire of motility behaviors. We use high-throughput 3D bacterial tracking to observe V. cholerae swimming in buffer, in viscous solutions of the synthetic polymer PVP, and in mucin solutions that may mimic the host environment. We perform a statistical characterization of its motility behavior on the basis of large 3D trajectory datasets. We find that V. cholerae performs asymmetric run-reverse-flick motility, consisting of a sequence of a forward run, reversal, and a shorter backward run, followed by a turn by approximately 90°, called a flick, preceding the next forward run. Unlike many run-reverse-flick swimmers, V. cholerae's backward runs are much shorter than its forward runs, resulting in an increased effective diffusivity. We also find that the swimming speed is not constant, but subject to frequent decreases. The turning frequency in mucin matches that observed in buffer. Run-reverse-flick motility and speed fluctuations are present in all environments studied, suggesting that these behaviors may also occur in natural aquatic habitats as well as the host environment.

10 THE ROLE OF DIETARY L-SERINE IN THE REGULATION OF INTESTINAL MUCUS BARRIER DURING INFLAMMATION

2020 ◽  
Vol 26 (Supplement_1) ◽  
pp. S42-S42
Author(s):  
Kohei Sugihara ◽  
Nobuhiko Kamada
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Gut Microbiota ◽  
Control Diet ◽  
Bacterial Strains ◽  
Germ Free ◽  
Intestinal Mucus ◽  
Gnotobiotic Mice ◽  
Mucus Barrier

Abstract Background Recent accumulating evidence suggests that amino acids have crucial roles in the maintenance of intestinal homeostasis. In inflammatory bowel disease (IBD), amino acid metabolism is changed in both host and the gut microbiota. Among amino acids, L-serine plays a central role in several metabolic processes that are essential for the growth and survival of both mammalian and bacterial cells. However, the role of L-serine in intestinal homeostasis and IBD remains incompletely understood. In this study, we investigated the effect of dietary L-serine on intestinal inflammation in a murine model of colitis. Methods Specific pathogen-free (SPF) mice were fed either a control diet (amino acid-based diet) or an L-serine-deficient diet (SDD). Colitis was induced by the treatment of dextran sodium sulfate (DSS). The gut microbiome was analyzed by 16S rRNA sequencing. We also evaluate the effect of dietary L-serine in germ-free mice and gnotobiotic mice that were colonized by a consortium of non-mucolytic bacterial strains or the consortium plus mucolytic bacterial strains. Results We found that the SDD exacerbated experimental colitis in SPF mice. However, the severity of colitis in SDD-fed mice was comparable to control diet-fed mice in germ-free condition, suggesting that the gut microbiota is required for exacerbation of colitis caused by the restriction of dietary L-serine. The gut microbiome analysis revealed that dietary L-serine restriction fosters the blooms of a mucus-degrading bacterium Akkermansia muciniphila and adherent-invasive Escherichia coli in the inflamed gut. Consistent with the expansion of mucolytic bacteria, SDD-fed mice showed a loss of the intestinal mucus layer. Dysfunction of the mucus barrier resulted in increased intestinal permeability, thereby leading to bacterial translocation to the intestinal mucosa, which subsequently increased the severity of colitis. The increased intestinal permeability and subsequent bacterial translocation were observed in SDD-fed gnotobiotic mice that colonized by mucolytic bacteria. In contrast, dietary L-serine restriction did not alter intestinal barrier integrity in gnotobiotic mice that colonized only by non-mucolytic bacteria. Conclusion Our results suggest that dietary L-serine regulates the integrity of the intestinal mucus barrier during inflammation by limiting the expansion of mucus degrading bacteria.

scholarly journals Development and characterization of probiotic mucilage based edible films for the preservation of fruits and vegetables

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Seyed Mohammad Davachi ◽  
Neethu Pottackal ◽  
Hooman Torabi ◽  
Alireza Abbaspourrad
Keyword(s):  
Fruits And Vegetables ◽  
Uv Light ◽  
Barrier Properties ◽  
Edible Films ◽  
Food Preservation ◽  
Elongation At Break ◽  
The Public ◽  
Medical Benefits ◽  
Seed Mucilage

AbstractThere is growing interest among the public and scientific community toward the use of probiotics to potentially restore the composition of the gut microbiome. With the aim of preparing eco-friendly probiotic edible films, we explored the addition of probiotics to the seed mucilage films of quince, flax, and basil. These mucilages are natural and compatible blends of different polysaccharides that have demonstrated medical benefits. All three seed mucilage films exhibited high moisture retention regardless of the presence of probiotics, which is needed to help preserve the moisture/freshness of food. Films from flax and quince mucilage were found to be more thermally stable and mechanically robust with higher elastic moduli and elongation at break than basil mucilage films. These films effectively protected fruits against UV light, maintaining the probiotics viability and inactivation rate during storage. Coated fruits and vegetables retained their freshness longer than uncoated produce, while quince-based probiotic films showed the best mechanical, physical, morphological and bacterial viability. This is the first report of the development, characterization and production of 100% natural mucilage-based probiotic edible coatings with enhanced barrier properties for food preservation applications containing probiotics.

scholarly journals Fabrication and characterization of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) modified with nano-montmorillonite biocomposite

e-Polymers ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 038-046
Author(s):  
Xu Yan ◽  
Wanru Zhou ◽  
Xiaojun Ma ◽  
Binqing Sun
Keyword(s):  
Thermal Stability ◽  
Oxygen Permeability ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
Nucleating Agent ◽  
Vapor Permeability ◽  
Casting Method ◽  
Increasing Trend ◽  
Solution Casting Method

Abstract In this study, a poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) modified with nano-montmorillonite biocomposite (MMT/PHBH) was fabricated by solution-casting method. The results showed that the addition of MMT increased the crystallinity and the number of spherulites, which indicated that MMT was an effective nucleating agent for PHBH. The maximum decomposition peak of the biocomposites moved to a high temperature and residue presented an increasing trend. The biocomposites showed the best thermal stability at 1 wt% MMT. Compared with PHBH, 182.5% and 111.2% improvement in elastic modulus and tensile strength were obtained, respectively. Moreover, the oxygen permeability coefficient and the water vapor permeability of MMT/PHBH biocomposites decreased by 43.9% and 6.9%, respectively. It was also found that the simultaneous enhancements on the crystallizing, thermal stability, mechanical, and barrier properties of biocomposites were mainly caused by the formation of intercalated structure between PHBH and MMT.

Microstructures and Characterization of Zirconia Coatings Formed by Laser Combined Plasma Spraying

1998 ◽  
Author(s):  
Z. Zhou ◽  
N. Eguchi ◽  
H. Shirasawa ◽  
A. Ohmori
Keyword(s):  
Laser Irradiation ◽  
Plasma Spraying ◽  
Barrier Properties ◽  
Thermal Barrier ◽  
Irradiation Treatment ◽  
Hybrid Plasma ◽  
Sprayed Coating ◽  
Steel Substrates ◽  
High Temperature Erosion

Abstract Hybrid plasma spraying combined with YAG laser irradiation was studied in order to obtain the optimum zirconia coatings for thermal barrier use. Zirconia coatings of approximately 150 ;Um in thickness were formed on the NiCrAlY under coated steel substrates both by means of conventional plasma spraying and hybrid plasma spraying under a variety of conditions. Post-laser irradiation was also conducted on the plasma as-sprayed coating for comparison. The microstructure of each coating was studied in detail and, for some representative coatings, thermal barrier properties were evaluated by hot erosion and a hot oxidation test. With hybrid spraying, performed under optimum conditions, it was found that a microstructure with appropriate partial densification and without connected porosities was formed and that cracks, which are generally produced in the post-laser irradiation treatment, were completely inhibited. In addition, hybrid spraying formed a smooth coating surface. These microstructural changes resulted in improved coating properties with regard to hardness, high temperature erosion resistance and oxidation resistance.

scholarly journals Frontline defenders: goblet cell mediators dictate host-microbe interactions in the intestinal tract during health and disease

2018 ◽  
Vol 314 (3) ◽  
pp. G360-G377 ◽  
Author(s):  
Joannie M. Allaire ◽  
Vijay Morampudi ◽  
Shauna M. Crowley ◽  
Martin Stahl ◽  
Hongbing Yu ◽  
...  
Keyword(s):  
Host Defense ◽  
Current Evidence ◽  
Gi Tract ◽  
Intestinal Mucus ◽  
Mucin 2 ◽  
Microbe Interactions ◽  
Noxious Stimuli ◽  
Sense And Respond ◽  
Mucus Barrier ◽  
Host Microbe Interactions

Goblet cells (GCs) are the predominant secretory epithelial cells lining the luminal surface of the mammalian gastrointestinal (GI) tract. Best known for their apical release of mucin 2 (Muc2), which is critical for the formation of the intestinal mucus barrier, GCs have often been overlooked for their active contributions to intestinal protection and host defense. In part, this oversight reflects the limited tools available to study their function but also because GCs have long been viewed as relatively passive players in promoting intestinal homeostasis and host defense. In light of recent studies, this perspective has shifted, as current evidence suggests that Muc2 as well as other GC mediators are actively released into the lumen to defend the host when the GI tract is challenged by noxious stimuli. The ability of GCs to sense and respond to danger signals, such as bacterial pathogens, has recently been linked to inflammasome signaling, potentially intrinsic to the GCs themselves. Moreover, further work suggests that GCs release Muc2, as well as other mediators, to modulate the composition of the gut microbiome, leading to both the expansion as well as the depletion of specific gut microbes. This review will focus on the mechanisms by which GCs actively defend the host from noxious stimuli, as well as describe advanced technologies and new approaches by which their responses can be addressed. Taken together, we will highlight current insights into this understudied, yet critical, aspect of intestinal mucosal protection and its role in promoting gut defense and homeostasis.

Design and characterization of a biocompatible packaging concept for implantable electronic devices

2011 ◽  
Vol 2011 (1) ◽  
pp. 000152-000160 ◽  
Author(s):  
Maaike Op de Beeck ◽  
Karen Qian ◽  
Paolo Fiorini ◽  
Karl Malachowski ◽  
Chris Van Hoof
Keyword(s):  
Diffusion Barrier ◽  
Barrier Properties ◽  
The Body ◽  
Second Phase ◽  
Electronic Systems ◽  
Wafer Level ◽  
Packaging Process ◽  
Directional Diffusion ◽  
Chip Sealing

A biocompatible packaging process for implantable electronic systems is described, combining biocompatibility and hermeticity with extreme miniaturization. In a first phase of the total packaging sequence, all chips are encapsulated in order to realize a bi-directional diffusion barrier preventing body fluids to leach into the package causing corrosion, and preventing IC materials such as Cu to diffuse into the body, causing various adverse effects. For cost effectiveness, this hermetic chip sealing is performed as post-processing at wafer level, using modifications of standard clean room (CR) fabrication techniques. Well known conductive and insulating CR materials are investigated with respect to their biocompatibility, diffusion barrier properties and sensitivity to corrosion. In a second phase of the packaging process, all chips of the final device should be electrically connected, applying a biocompatible metallization scheme using eg. gold or platinum. For electrodes being in direct contact with the tissue after implantation, IrOx metallization is proposed. Device assembly is the final packaging step, during which all system components such as electronics, passives, a battery,… will be interconnected. To provide sufficient mechanical support, all these components are embedded using a biocompatible elastomer such as PDMS.

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