| 1. |
- Campbell, Kate, 1987, et al.
(författare)
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Self-Establishing Communities: A Yeast Model to Study the Physiological Impact of Metabolic Cooperation in Eukaryotic Cells
- 2019
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Ingår i: Methods in Molecular Biology. - New York, NY : Springer New York. - 1940-6029 .- 1064-3745. ; , s. 263-282
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- All biosynthetically active cells are able to export and import metabolites, the small molecule intermediaries of metabolism. In dense cell populations, this hallmark of cells results in the intercellular exchange of a wide spectrum of metabolites. Such metabolite exchange enables metabolic specialization of individual cells, leading to far reaching biological implications, as a consequence of the intrinsic connection between metabolism and cell physiology. In this chapter, we discuss methods on how to study metabolite exchange interactions by using self-establishing metabolically cooperating communities (SeMeCos) in the budding yeast Saccharomyces cerevisiae. SeMeCos exploit the stochastic segregation of episomes to progressively increase the number of essential metabolic interdependencies in a community that grows out from an initially prototrophic cell. By coupling genotype to metabotype, SeMeCos allow for the tracking of cells while they specialize metabolically and hence the opportunity to study their progressive change in physiology.
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| 2. |
- Jesorka, Aldo, 1967, et al.
(författare)
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Microfluidic technology for investigation of protein function in single adherent cells
- 2019
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Ingår i: Methods in Enzymology. - : Elsevier. - 1557-7988 .- 0076-6879.
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Instrumental techniques and associated methods for single cell analysis, designed to investigate and measure a broad range of cellular parameters in search of unique features, address key limitations of conventional cell-based assays with their ensemble average response. While many different single cell techniques exist for suspension cultures, which can process and characterize large numbers of individual cells in rapid succession, the access to surface-immobilized cells in typical 2D and 3D culture environments remains challenging. Open space microfluidics has created new possibilities in this area, allowing for exclusive access to single cells in adherent cultures, even at high confluency. In this chapter, we briefly review new microtechnologies for the investigation of protein function in single adherent cells, and present an overview over related recent applications of the multifunctional pipette (Biopen), a microfluidic multi-solution dispensing system that uses hydrodynamic confinement in open volume environments in order to establish a superfusion zone over selected single cells in adherent cultures.
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| 3. |
- Padma, Arvind M., et al.
(författare)
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Protocols for Rat Uterus Isolation and Decellularization: Applications for Uterus Tissue Engineering and 3D Cell Culturing.
- 2018
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Ingår i: Decellularized Scaffolds and Organogenesis. Kursad Turksen (red.). - New York, NY : Springer. - 1940-6029. - 9781493976553 ; , s. 161-175
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Bokkapitel (refereegranskat)abstract
- Sophisticated culturing conditions are required to grow cells in a three-dimensional (3D) environment. Cells then require a type of scaffold rich in proteins, growth factors, and signaling molecules that simulates their natural environment. Tissues from all species of animals have an organ-specific extracellular matrix (ECM) structure that plays a key role in cell proliferation and migration. Hence, the scaffold composition plays a significant role for any successful 3D cell culturing system. We developed a whole rat uterus ECM scaffold by the perfusion of detergents and ionic solutions through the vascular system of an isolated normal rat uterus in a process termed "decellularization." The generated rat uterus scaffolds consist of a cell-free ECM structure similar to that of the normal rat uterus, and are thus excellent platforms on to which new cells can be added. Rat uterus 3D cell culturing systems based on these scaffolds could become valuable to decidual differentiation- and embryo implantation studies, or for investigating invasion mechanisms of endometrial cancer cells. They could also be used for the creation of tissue engineered uterine tissue, for partial or whole organogenesis developed for transplantation applications to treat absolute uterine infertility. This is a condition affecting about 1 in 500 women, and is only treatable by a uterus transplantation. This article provides valuable troubleshooting notes and describes in detail how to generate rat uterus scaffolds, including the delicate surgery required to isolate the uterus with an intact vascular tree which facilitates vascular perfusion and re-transplantation.
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| 4. |
- Shah, Furqan A., et al.
(författare)
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Bioactive glass and glass-ceramic scaffolds for bone tissue engineering
- 2018
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Ingår i: Bioactive Glasses (Second Edition). - 9780081009369 ; , s. 201-33
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Bioactive glasses and glass-ceramics are a diverse group of materials possessing a unique set of physicochemical properties that make them useful for bone repair. Scaffolds for bone tissue engineering are subject to many requirements including biocompatibility, osteogenesis, biodegradability, and mechanical competence, all of which must be considered in the design features. This chapter addresses various scaffold fabrication techniques for melt-derived and sol-gel-derived compositions, polymer-based organic-inorganic composites, calcium phosphate-based inorganic-inorganic composites, bioactive bone cements, scaffolds based on glass compositions containing specific therapeutic ions, and hybrid materials where the organic and inorganic phases interact at the molecular level. The most important achievements, challenges and potential solutions, as well as the most promising areas of future research involving bioactive glasses and glass-ceramics for bone tissue engineering are presented.
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| 5. |
- Pless, Christian J., et al.
(författare)
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Emerging strategies in 3D printed tissue models for in vitro biomedical research
- 2022
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Ingår i: Bioprinting : From Multidisciplinary Design to Emerging Opportunities - From Multidisciplinary Design to Emerging Opportunities. - 9780323854313 - 9780323854306 ; , s. 207-246
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Bokkapitel (refereegranskat)abstract
- 3D bioprinting has the potential to provide a unified framework for the manufacturing of tissue models for biomedical research, including drug discovery, disease modeling, and regenerative medicine. However, it remains challenging to 3D print replicas of human tissues that have accurate cell types, cellular densities, extracellular matrix compositions, and that can be assayed in a minimally invasive manner for chronic studies. Here, we review how recent breakthroughs in stem cell biology, tissue engineering, and materials science have led to novel 3D printing strategies that have the potential to solve these challenges.
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| 6. |
- Asa'ad, Farah, 1983, et al.
(författare)
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Genetic and Epigenetic Susceptibility of Peri-Implantitis
- 2022
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Ingår i: Unfolding Peri-implantitis: Diagnosis, Prevention. - Spain : Quintessence. - 9788489873896
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Bokkapitel (refereegranskat)abstract
- Peri-implantitis is a destructive disease of implant-supporting tissues induced by bacterial biofilm, which provokes an inflammatory host response, influenced by environmental, genetic, and epigenetic factors. Genetics is the science that deals with genes, heredity, and the variations that occur in our genes and DNA, while epigenetics refers to alterations in the gene expression that are not encoded in the DNA sequence, which result in the remodeling of the chromatin and activation or inactivation of a gene. There are three major epigenetic mechanisms: DNA methylation, histone modifications, and microRNAs. The relationship between genetics, epigenetics, and peri-implantitis has been the subject of interest in the recent years; therefore, we aim in this chapter to present the state of the art on the role of genetic and epigenetic mechanisms in peri-implantitis.
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| 7. |
- Antoni, Gunnar, et al.
(författare)
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Molecular Imaging of Transporters with Positron Emission Tomography
- 2009
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Ingår i: Transporters as Targets for Drugs. - Berlin : Springer. - 3540879110 - 9783540879121 - 9783540879114 ; , s. 155-186
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Bokkapitel (refereegranskat)abstract
- Positron emission tomography (PET) visualization of brain components in vivo is a rapidly growing field. Molecular imaging with PET is also increasingly used in drug development, especially for the determination of drug receptor interaction for CNS-active drugs. This gives the opportunity to relate clinical efficacy to per cent receptor occupancy of a drug on a certain targeted receptor and to relate drug pharmacokinetics in plasma to interaction with target protein. In the present review we will focus on the study of transporters, such as the monoamine transporters, the P-glycoprotein (Pgp) transporter, the vesicular monoamine transporter type 2, and the glucose transporter using PET radioligands. Neurotransmitter transporters are presynaptically located and in vivo imaging using PET can therefore be used for the determination of the density of afferent neurons. Several promising PET ligands for the noradrenaline transporter (NET) have been labeled and evaluated in vivo including in man, but a really useful PET ligand for NET still remains to be identified. The most promising tracer to date is (S,S)-[18F]FMeNER-D2. The in vivo visualization of the dopamine transporter (DAT) may give clues in the evaluation of conditions related to dopamine, such as Parkinson's disease and drug abuse. The first PET radioligands based on cocaine were not selective, but more recently several selective tracers such as [11C]PE2I have been characterized and shown to be suitable as PET radioligands. Although there are a large number of serotonin transporter inhibitors used today as SSRIs, it was not until very recently, when [11C]McN5652 was synthesized, that this transporter was studied using PET. New candidates as PET radioligands for the SERT have subsequently been developed and [11C]DASB and [11C]MADAM and their analogues are today the most promising ligands. The existing radioligands for Pgp transporters seem to be suitable tools for the study of both peripheral and central drug–Pgp interactions, although [11C]verapamil and [18F]fluoropaclitaxel are probably restricted to use in studies of the blood–brain barrier. The vesicular monoamine transporter 2 (VMAT2) is another interesting target for diagnostic imaging and [11C]DTBZ is a promising tracer. The noninvasive imaging of transporter density as a function of disease progression or availability following interaction with blocking drugs is highlighted, including the impact on both development of new therapies and the process of developing new drugs. Although CNS-related work focusing on psychiatric disorders is the main focus of this review, other applications of PET ligands, such as diagnosis of cancer, diabetes research, and drug interactions with efflux systems, are also discussed. The use of PET especially in terms of tracer development is briefly described. Finally, it can be concluded that there is an urgent need for new, selective radioligands for the study of the transporter systems in the human brain using PET.
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| 8. |
- Arnqvist, Anna
(författare)
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Roles of the BabA and the SabA adhesins in gastroduodenal diseases
- 2016
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Ingår i: Helicobacter pylori research. - Tokyo : Springer. - 9784431559368 - 9784431559344 ; , s. 143-164
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Bokkapitel (refereegranskat)abstract
- Adhesion is an important prerequisite for colonization and it is the initial step in infections with pathogenic bacteria. Adherence to host epithelial surfaces is the result of bacterial surface proteins, called adhesins, and their specific interaction with cognate protein- or glycoconjugate receptors on the host cells. Often, the bacteria have a set of complementary adhesins that are specific for different host receptors. Alternative mechanism has been suggested to mediate H. pylori adhesion, and this chapter will focus on the two well-characterized adhesins BabA and SabA. In the healthy gastric mucosa, the Lewis b antigen (Leb) is present in the gastric epithelial lining of blood group O (H-antigen), B, and A individuals. H. pylori binding to ABO/Leb is mediated by the blood group antigen-binding BabA adhesin. As the inflammation develops, Leb is downregulated and the levels of sialylated antigens increase. Sialyl-Lewis x/a antigens (sLex/a) are specifically recognized by the H. pylori sialic acid-binding adhesin SabA. Even though bacterial adherence per se cannot cause disease, adherence is considered as a crucial step in pathogenesis since it is needed for bacterial delivery of effector molecules into the host cell. The presence of receptors and host-immune responses are two factors that differently affect adhesion. To achieve long-term colonization, H. pylori must regulate the expression of a cognate adhesin to fit the available receptors. Adhesion to the gastric epithelial cells promotes gain of nutrients, but too tight adhesion may be intimidating because of the risk of clearance by the bacteria for life-threatening immune responses. Thus, expression levels of the adhesins must be fine-tuned in accord to host receptor expression levels. This chapter will also discuss H. pylori adhesion in relation to severe gastric diseases.
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| 9. |
- Axner, Ove, 1957-, et al.
(författare)
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Assessing bacterial adhesion on an individual adhesin and single pili level using optical tweezers
- 2011
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Ingår i: Bacterial adhesion. - Berlin : Springer Berlin/Heidelberg. ; , s. 301-313
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Bokkapitel (refereegranskat)abstract
- Optical tweezers (OT) are a technique that, by focused laser light, can both manipulate micrometer sized objects and measure minute forces (in the pN range) in biological systems. The technique is therefore suitable for assessment of bacterial adhesion on an individual adhesin-receptor and single attachment organelle (pili) level. This chapter summarizes the use of OT for assessment of adhesion mechanisms of both non-piliated and piliated bacteria. The latter include the important helix-like pili expressed by uropathogenic Escherichia coli (UPEC), which have shown to have unique and intricate biomechanical properties. It is conjectured that the large flexibility of this type of pili allows for a redistribution of an external shear force among several pili, thereby extending the adhesion lifetime of bacteria. Systems with helix-like adhesion organelles may therefore act as dynamic biomechanical machineries, enhancing the ability of bacteria to withstand high shear forces originating from rinsing flows such as in the urinary tract. This implies that pili constitute an important virulence factor and a possible target for future anti-microbial drugs.
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| 10. |
- Bergman, Alexandra Linda, 1985, et al.
(författare)
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Metabolic Engineering Strategies to Convert Carbohydrates to Aviation Range Hydrocarbons
- 2016
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Ingår i: Biofuels for Aviation: Feedstocks, Technology and Implementation. - 9780128045688 ; , s. 151-190
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Numerous hydrocarbon molecules with properties similar to aviation fuels can be found in nature, but are often only produced at low quantities in their native hosts. This chapter summarizes recent progress in the engineering of microbial cell factories for the production of the two major molecule classes: fatty acid-derived alkanes/alkanes and isoprenoids. It starts with a brief introduction to metabolic engineering. For each of the two molecule classes, it provides information on biosynthetic pathways as well as engineering strategies to enhance their formation in the microbial hosts. While most of these endeavours are still at the proof-of concept stage, the first commercial examples are beginning to emerge.
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