scholarly journals Stepwise construction of dynamic microscale concentration gradients around hydrogel-encapsulated cells in a microfluidic perfusion culture device

2020 ◽  
Vol 7 (7) ◽  
pp. 200027
Author(s):  
Shinya Yamahira ◽  
Taku Satoh ◽  
Fumiki Yanagawa ◽  
Masato Tamura ◽  
Toshiyuki Takagi ◽  
...  
Keyword(s):  
Culture Medium ◽  
Perfusion Culture ◽  
Biological Processes ◽  
Concentration Gradients ◽  
Encapsulated Cells ◽  
Microfluidic Perfusion ◽  
Research Environments ◽  
Novel Method ◽  
Dynamic Concentration ◽  
Living Organisms

Inside living organisms, concentration gradients dynamically change over time as biological processes progress. Therefore, methods to construct dynamic microscale concentration gradients in a spatially controlled manner are needed to provide more realistic research environments. Here, we report a novel method for the construction of dynamic microscale concentration gradients in a stepwise manner around cells in micropatterned hydrogel. In our method, cells are encapsulated in a photodegradable hydrogel formed inside a microfluidic perfusion culture device, and perfusion microchannels are then fabricated in the hydrogel by micropatterned photodegradation. The cells in the micropatterned hydrogel can then be cultured by perfusing culture medium through the fabricated microchannels. By using this method, we demonstrate the simultaneous construction of two dynamic concentration gradients, which allowed us to expose the cells encapsulated in the hydrogel to a dynamic microenvironment.

Environmental significance of atrazine in aqueous systems and its removal by biological processes: an overview

2013 ◽  
Vol 8 (2) ◽  
pp. 159-178 ◽  
Keyword(s):  
Drinking Water ◽  
Ground Water ◽  
Water Environment ◽  
Biological Processes ◽  
Biological Degradation ◽  
Environmental Significance ◽  
Carbon And Nitrogen ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio ◽  
Living Organisms

Atrazine, a chlorinated s-triazine group of herbicide is one of the most widely used pesticides in the World. Due to its extensive use, long half-life and various toxic properties, it has very high environmental significance. Up to 22 mg l-1 of atrazine was found in ground water whereas permissible limit of atrazine is in ppb level in drinking water. As per Indian standard there should not be any pesticide present in drinking water. Among many other treatment processes available, Incineration, adsorption, chemical treatment, phytoremediation and biodegradation are the most commonly used ones. Biological degradation of atrazine depends upon various factors like the operating environment, external carbon and nitrogen sources, carbon/ nitrogen ratio (C/N), water content and the bacterial strain. Although, general atrazine degradation pathways are available, the specific pathways in specific conditions are not yet clearly defined. In this paper extensive review has been made on the occurrence of atrazine in surface and ground water bodies, probable sources and causes of its occurrence in water environment, the toxicity of atrazine on various living organisms and its removal by biological processes.

Influence of sterilization conditions on sulfate-functionalized polyGGE

2021 ◽  
pp. 1-12
Author(s):  
Shuo Zhou ◽  
Xun Xu ◽  
Nan Ma ◽  
Friedrich Jung ◽  
Andreas Lendlein
Keyword(s):  
Microbial Contamination ◽  
Gamma Ray ◽  
Glycidyl Ether ◽  
Biological Processes ◽  
Chain Mobility ◽  
Functionalized Materials ◽  
Polymeric Implants ◽  
Gamma Ray Irradiation ◽  
Group Density ◽  
Living Organisms

Sulfated biomolecules are known to influence numerous biological processes in all living organisms. Particularly, they contribute to prevent and inhibit the hypercoagulation condition. The failure of polymeric implants and blood contacting devices is often related to hypercoagulation and microbial contamination. Here, bioactive sulfated biomacromolecules are mimicked by sulfation of poly(glycerol glycidyl ether) (polyGGE) films. Autoclaving, gamma-ray irradiation and ethylene oxide (EtO) gas sterilization techniques were applied to functionalized materials. The sulfate group density and hydrophilicity of sulfated polymers were decreased while chain mobility and thermal degradation were enhanced post autoclaving when compared to those after EtO sterilization. These results suggest that a quality control after sterilization is mandatory to ensure the amount and functionality of functionalized groups are retained.

scholarly journals Acanthamoeba-Campylobacter Coculture as a Novel Method for Enrichment of Campylobacter Species

2007 ◽  
Vol 73 (21) ◽  
pp. 6864-6869 ◽  
Author(s):  
Diana Axelsson-Olsson ◽  
Patrik Ellstr�m ◽  
Jonas Waldenstr�m ◽  
Paul D. Haemig ◽  
Lars Brudin ◽  
...  
Keyword(s):  
Culture Medium ◽  
Bacterial Species ◽  
Oxygen Quenching ◽  
Free Living ◽  
Promising Tool ◽  
Low Concentrations ◽  
Novel Method ◽  
Selective Antibiotics ◽  
Different Sources ◽  
Bacterial Concentrations

ABSTRACT In this study, we present a novel method to isolate and enrich low concentrations of Campylobacter pathogens. This method, Acanthamoeba-Campylobacter coculture (ACC), is based on the intracellular survival and multiplication of Campylobacter species in the free-living protozoan Acanthamoeba polyphaga. Four of the Campylobacter species relevant to humans and livestock, Campylobacter jejuni, C. coli, C. lari, and C. hyointestinalis, were effectively enriched by the coculture method, with growth rates comparable to those observed in other Campylobacter enrichment media. Studying six strains of C. jejuni isolated from different sources, we found that all of the strains could be enriched from an inoculum of fewer than 10 bacteria. The sensitivity of the ACC method was not negatively affected by the use of Campylobacter-selective antibiotics in the culture medium, but these were effective in suppressing the growth of seven different bacterial species added at a concentration of 104 CFU/ml of each species as deliberate contamination. The ACC method has advantages over other enrichment methods as it is not dependent on a microaerobic milieu and does not require the use of blood or other oxygen-quenching agents. Our study found the ACC method to be a promising tool for the enrichment of Campylobacter species, particularly from water samples with low bacterial concentrations.

Glycan Labeling and Analysis in Cells and In Vivo

2021 ◽  
Vol 14 (1) ◽  
pp. 363-387
Author(s):  
Bo Cheng ◽  
Qi Tang ◽  
Che Zhang ◽  
Xing Chen
Keyword(s):  
Chemical Modification ◽  
Biological Function ◽  
Biological Processes ◽  
Affinity Tags ◽  
Functional Roles ◽  
Antibody Conjugates ◽  
Living Organisms ◽  
In Cells

As one of the major types of biomacromolecules in the cell, glycans play essential functional roles in various biological processes. Compared with proteins and nucleic acids, the analysis of glycans in situ has been more challenging. Herein we review recent advances in the development of methods and strategies for labeling, imaging, and profiling of glycans in cells and in vivo. Cellular glycans can be labeled by affinity-based probes, including lectin and antibody conjugates, direct chemical modification, metabolic glycan labeling, and chemoenzymatic labeling. These methods have been applied to label glycans with fluorophores, which enables the visualization and tracking of glycans in cells, tissues, and living organisms. Alternatively, labeling glycans with affinity tags has enabled the enrichment of glycoproteins for glycoproteomic profiling. Built on the glycan labeling methods, strategies enabling cell-selective and tissue-specific glycan labeling and protein-specific glycan imaging have been developed. With these methods and strategies, researchers are now better poised than ever to dissect the biological function of glycans in physiological or pathological contexts.

scholarly journals Treating Senescence like Cancer: Novel Perspectives in Senotherapy of Chronic Diseases

2020 ◽  
Vol 21 (21) ◽  
pp. 7984
Author(s):  
Alessia Mongelli ◽  
Sandra Atlante ◽  
Veronica Barbi ◽  
Tiziana Bachetti ◽  
Fabio Martelli ◽  
...  
Keyword(s):  
Chronic Diseases ◽  
Cell Senescence ◽  
Biological Processes ◽  
Social Relevance ◽  
Chemical Agents ◽  
Age Related ◽  
Living Organisms ◽  
Specific Pathway

The WHO estimated around 41 million deaths worldwide each year for age-related non-communicable chronic diseases. Hence, developing strategies to control the accumulation of cell senescence in living organisms and the overall aging process is an urgently needed problem of social relevance. During aging, many biological processes are altered, which globally induce the dysfunction of the whole organism. Cell senescence is one of the causes of this modification. Nowadays, several drugs approved for anticancer therapy have been repurposed to treat senescence, and others are under scrutiny in vitro and in vivo to establish their senomorphic or senolytic properties. In some cases, this research led to a significant increase in cell survival or to a prolonged lifespan in animal models, at least. Senomorphics can act to interfere with a specific pathway in order to restore the appropriate cellular function, preserve viability, and to prolong the lifespan. On the other hand, senolytics induce apoptosis in senescent cells allowing the remaining non–senescent population to preserve or restore tissue function. A large number of research articles and reviews recently addressed this topic. Herein, we would like to focus attention on those chemical agents with senomorphic or senolytic properties that perspectively, according to literature, suggest a potential application as senotherapeutics for chronic diseases.

scholarly journals BCSExplorer: a customized biosynthetic chemical space explorer with multifunctional objective function analysis

2019 ◽  
Author(s):  
Yu Tian ◽  
Ling Wu ◽  
Le Yuan ◽  
Shaozhen Ding ◽  
Fu Chen ◽  
...  
Keyword(s):  
Chemical Space ◽  
Function Analysis ◽  
Supplementary Information ◽  
Bulk Chemicals ◽  
Toxicity Analysis ◽  
Novel Method ◽  
Living Organisms ◽  
Almost All ◽  
New Generation ◽  
Rule Library

Abstract Summary The biosynthetic ability of living organisms has important applications in producing bulk chemicals, biofuels and natural products. Based on the most comprehensive biosynthesis knowledgebase, a computational system, BCSExplorer, is proposed to discover the unexplored chemical space using nature’s biosynthetic potential. BCSExplorer first integrates the most comprehensive biosynthetic reaction database with 280 000 biochemical reactions and 60 000 chemicals biosynthesized globally over the past 130 years. Second, in this study, a biosynthesis tree is computed for a starting chemical molecule based on a comprehensive biotransformation rule library covering almost all biosynthetic possibilities, in which redundant rules are removed using a new algorithm. Moreover, biosynthesis feasibility, drug-likeness and toxicity analysis of a new generation of compounds will be pursued in further studies to meet various needs. BCSExplorer represents a novel method to explore biosynthetically available chemical space. Availability and implementation BCSExplorer is available at: http://www.rxnfinder.org/bcsexplorer/. Supplementary information Supplementary data are available at Bioinformatics online.

scholarly journals Oxidative Stress Applied in Diabetes Mellitus-A New Paradigm

Proceedings ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 7
Author(s):  
Pantea Stoian ◽  
Mitrofan ◽  
Colceag ◽  
Serafinceanu ◽  
Eftimie Totu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Alternative Methods ◽  
Biological Processes ◽  
New Paradigm ◽  
Medical Practitioners ◽  
Complex Systems Theory ◽  
Network Concept ◽  
Living Organisms ◽  
Pathogenic Process

Although obesity and a sedentary lifestyle are well-known risk factors for type 2 diabetes, at molecular level, the oxidative stress is regarded as the primary contributor to the pathogenic process. Our work intends to evidence how the thinking models influence the way that medical practitioners understand the pathogenic mechanisms. Some research groups focused lately on the system’s dynamics and Complex Systems Theory. The living organisms as a complex system could be analyzed applying the network concept. Alternative methods for characterizing biological processes or phenomena based on feedback node structure have been developed [1].

scholarly journals Gold Bioleaching from Printed Circuit Boards of Mobile Phones by Aspergillus niger in a Culture without Agitation and with Glucose as a Carbon Source

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 521 ◽  
Author(s):  
Rosalba Argumedo-Delira ◽  
Mario J. Gómez-Martínez ◽  
Brenda Joan Soto
Keyword(s):  
Aspergillus Niger ◽  
Carbon Source ◽  
Culture Medium ◽  
Printed Circuit Boards ◽  
Biological Processes ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Material Resources ◽  
Low Energy Consumption ◽  
Fungal Consortium

Hydrometallurgical and pyrometallurgical processes to recover gold (Au) from cell-phone printed circuit boards (PCBs) have the disadvantage of generating corrosive residues and consuming a large amount of energy. Therefore, it is necessary to look for biological processes that have low energy consumption and are friendly to the environment. Among the biological alternatives for the recovery of Au from PCB is the use of cyanogenic bacteria and filamentous fungi in cultures with agitation. Considering that it is important to explore the response of microorganisms in cultures without agitation to reduce energy expenditure in the recovery of metals from PCB, the present investigation evaluated the capacity of Aspergillus niger MXPE6 and a fungal consortium to induce Au bioleaching from PCB in a culture medium with glucose as a carbon source and without agitation (pH 4.5). The results indicate that the treatments with PCB inoculated with the fungal consortium showed a considerable decrease in pH (2.8) in comparison with the treatments inoculated with A. niger MXPE6 (4.0). The fungal consortium showed a significantly higher Au bioleaching (56%) than A. niger MXPE6 (17%). Finally, the use of fungal consortia grown without agitation could be an alternative to recover metals from PCB, saving energy and material resources.

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