| 1. |
- Gerlach, Inga
(författare)
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Operator Training Simulators towards Industrial Biotechnology
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Biotechnological processes are carried out by applying advanced and demanding process strategies. Thus, fundamental understanding and knowledge about the applied microorganism is required to achieve high productivity and profitability. Therefore, computer-based simulation has been integrated into training methodologies for supplementing and expanding academic education and industrial operator training, in order to provide more effective as well as cost- and time-efficient training.Operator training simulators (OTS) are computer-based training tools that represent the real laboratory or plant within an interactive, virtual environment. Trainees can learn about cause-and-effect relationships during the virtual process to improve process understanding. Also, trainees and operators get the opportunity to develop, maintain and improve their operational skills. The virtual environment allows delayed operational actions and operational faults, as they are not interfering with the real process. Acceleration of the simulation speed makes training more effective. For instance, different procedures such as start-up and shut-down can be trained in a limited period of training time. Incident and trouble-shooting training can be realized in a safe, virtual environment without exposing the operator to potential risks. So far, OTS are mainly used in military, aviation, medicine and chemical industries. However, there are only a few examples where OTS are applied in biotechnological process applications.The aim of this thesis is to expose the benefits of using OTS for biotechnological process applications in academic education and industrial operator training. For this purpose, the feasibility of developing and applying OTS was investigated and discussed. Three OTS for the production of bio-ethanol and recombinant protein production were developed in order to investigate the benefits and their requirements as well as to assess the training effectiveness of these. To visualize the technical system including equipment and distributed control system (DCS), graphical user interfaces (GUIs) were designed, allowing the user to interact with the simulator. Mathematical models were developed and implemented in the OTS to ensure dynamic simulation of the process, where cause-and-effect relationships are realistically described. The essential part of an OTS for biotechnological process applications is the embedded sub-model which describes the biological production system. It is important that the cell growth behaviour within a bioreactor can be simulated with sufficient accuracy in order to ensure high training effectiveness.In the assessment of the training effectiveness in academic education, it was observed that the students’ capability of understanding and controlling complex biotechnological processes improved after OTS training. Students showed better performance in laboratory experiments after participating in OTS pre-training. Moreover, the development of an OTS for an industrial, large-scale bio-ethanol plant illuminates the needs of OTS in biotechnological process industries. It was shown how the conceptual design methodology can be applied in designing an OTS, based on training needs from the industrial user perspective. Also, construction of the OTS including the formulation of mathematical models, the model structure which is embedded in the OTS and the design of the GUIs is covered in this thesis. Whether the use of the OTS will become cost-effective and assure maximum transfer of training depends on long term evaluation. However, application and evaluation of the developed OTS reveal the benefits and training effectiveness of these systems. The findings of the thesis might considerably facilitate the introduction of OTS into academic education and industrial operator training for biotechnological process applications.
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| 2. |
- Gustavsson, Robert, 1987-
(författare)
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Development of soft sensors for monitoring and control of bioprocesses
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the manufacture of bio-therapeutics the importance of a well-known process is key for a high product titer and low batch to batch variations. Soft sensors are based on the concept that online sensor signals can be used as inputs to mathematical models to derive new valuable process information. This information could then be used for better monitoring and control of the bioprocess.The aim of the present thesis has been to develop soft sensor solutions for upstream bioprocessing and demonstrate their usefulness in improving robustness and increase the batch-to-batch reproducibility in bioprocesses. The thesis reviews the potential and possibilities with soft sensors for use in production of bio-therapeutics to realize FDA´s process analytical technology (PAT) initiative. Modelling and hardware sensor alternatives which could be used in a soft sensor setup are described and critically analyzed. Different soft sensor approaches to control glucose feeding in fed-batch cultures of Escherichia coli are described. Measurements of metabolic fluxes and specific carbon dioxide production was used as control parameters to increase product yield and decrease the variability of produced recombinant proteins. Metabolic heat signals were used in uninduced cultures to estimate and control the specific growth rate at a desired level and thereby also estimate the biomass concentration online. The introduction of sequential filtering of the signal enabled this method to be used in a down-scaled system. The risk and high impact of contaminations in cell cultures are also described. An in situ microscope (ISM) was used as an online tool to estimate cell concentration and also to determine cell diameter size which enabled the detection of contaminant cells at an early stage.The work presented in this thesis supports the idea that soft sensors can be a useful tool in the strive towards robust and reliable bioprocesses, to ensure high product quality and increased economic profit.
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| 3. |
- Andersson, Henrik, et al.
(författare)
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Assaying cardiac biomarkers for toxicity testing using biosensing and cardiomyocytes derived from human embryonic stem cells
- 2010
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Ingår i: JOURNAL OF BIOTECHNOLOGY. - : Elsevier Science B.V., Amsterdam.. - 0168-1656 .- 1873-4863. ; 150:1, s. 175-181
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Tidskriftsartikel (refereegranskat)abstract
- Human embryonic stem cell (hESC) derived cardiomyocytes are in the present study being used for testing drug-induced cardiotoxicity in a biosensor set-up. The design of an in vitro testing alternative provides a novel opportunity to surpass previous methods based on rodent cells or cell lines due to its significantly higher toxicological relevance. In this report we demonstrate how hESC-derived cardiomyocytes release detectable levels of two clinically decisive cardiac biomarkers, cardiac troponin T and fatty acid binding protein 3, when the cardiac cells are exposed to the well-known cardioactive drug compound. doxorubicin. The release is monitored by the immuno-biosensor technique surface plasmon resonance, particularly appropriate due to its capacity for parallel and high-throughput analysis in complex media.
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| 4. |
- Andersson, Henrik, et al.
(författare)
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Monitoring of troponin release from cardiomyocytes during exposure to toxic substances using surface plasmon resonance biosensing
- 2010
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Ingår i: ANALYTICAL AND BIOANALYTICAL CHEMISTRY. - : Springer Science Business Media. - 1618-2642 .- 1618-2650. ; 398:3, s. 1395-1402
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Tidskriftsartikel (refereegranskat)abstract
- Troponin T (TnT) is a useful biomarker for studying drug-induced toxicity effects on cardiac cells. We describe how a surface plasmon resonance (SPR) biosensor was applied to monitor the release of TnT from active HL-1 cardiomyocytes in vitro when exposed to cardiotoxic substances. Two monoclonal human TnT antibodies were compared in the SPR immunosensor to analyse the TnT release. The detection limit of TnT was determined to be 30 ng/ml in a direct assay set-up and to be 10 ng/ml in a sandwich assay format. Exposure of the cardiomyocytes to doxorubicin, troglitazone, quinidine and cobalt chloride for periods of 6 and 24 h gave significant SPR responses, whereas substances with low toxicity showed insignificant effects (ascorbic acid, methotrexate). The SPR results were verified with a validated immunochemiluminescence method which showed a correlation of r(2)=0.790.
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| 5. |
- Aronsson, Christopher, et al.
(författare)
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Dynamic peptide-folding mediated biofunctionalization and modulation of hydrogels for 4D bioprinting
- 2020
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Ingår i: Biofabrication. - : Institute of Physics Publishing (IOPP). - 1758-5082 .- 1758-5090. ; 12:3
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Tidskriftsartikel (refereegranskat)abstract
- Hydrogels are used in a wide range of biomedical applications, including three-dimensional (3D) cell culture, cell therapy and bioprinting. To enable processing using advanced additive fabrication techniques and to mimic the dynamic nature of the extracellular matrix (ECM), the properties of the hydrogels must be possible to tailor and change over time with high precision. The design of hydrogels that are both structurally and functionally dynamic, while providing necessary mechanical support is challenging using conventional synthesis techniques. Here, we show a modular and 3D printable hydrogel system that combines a robust but tunable covalent bioorthogonal cross-linking strategy with specific peptide-folding mediated interactions for dynamic modulation of cross-linking and functionalization. The hyaluronan-based hydrogels were covalently cross-linked by strain-promoted alkyne-azide cycloaddition using multi-arm poly(ethylene glycol). In addition, a de novo designed helix-loop-helix peptide was conjugated to the hyaluronan backbone to enable specific peptide-folding modulation of cross-linking density and kinetics, and hydrogel functionality. An array of complementary peptides with different functionalities was developed and used as a toolbox for supramolecular tuning of cell-hydrogel interactions and for controlling enzyme-mediated biomineralization processes. The modular peptide system enabled dynamic modifications of the properties of 3D printed structures, demonstrating a novel route for design of more sophisticated bioinks for four-dimensional bioprinting. © 2020 The Author(s). Published by IOP Publishing Ltd.
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| 6. |
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| 7. |
- Axelsson, Jan Peter, et al.
(författare)
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Computer Control of Sucrose Concentration in a Fermentor with Continuous Flow
- 1983
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Ingår i: Modelling and Control of Biotechnical Processes : Proceedings of the First IFAC Workshop, Helsinki, Finland, August 17–19, 1982 - Proceedings of the First IFAC Workshop, Helsinki, Finland, August 17–19, 1982. - 9780080299785 ; , s. 273-282
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Bokkapitel (refereegranskat)
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| 8. |
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| 9. |
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| 10. |
- Bachinger, T., et al.
(författare)
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Electronic nose for estimation of product concentration in mammalian cell cultivation
- 2000
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Ingår i: Bioprocess engineering (Berlin. Print). - : Springer Science and Business Media LLC. - 0178-515X .- 1432-0797 .- 1615-7591. ; 23:6, s. 637-642
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Tidskriftsartikel (refereegranskat)abstract
- The off-gas composition from perfusion cultivation of a CHO-cell line producing recombinant human blood coagulation Factor VIII is monitored with an electronic nose. It is shown that the electronic nose in combination with an artificial neural network can be used for on-line estimation of the Factor VIII concentration in production-scale cultivations. The obtained prediction error (1s) for the Factor VIII concentration was 1.1 IU/ml. The potential of the electronic nose for estimation of viable cell count is outlined in laboratory-scale Factor VIII cultivations. The obtained prediction error (1s) for the viable cell count was 0.4 ╫ 106 cells/ml. The results show that this non-invasive method is potentially useful for on-line bioprocess monitoring.
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| 11. |
- Bachinger, T., et al.
(författare)
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Gas sensor arrays for early detection of infection in mammalian cell culture
- 2002
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Ingår i: Biosensors & bioelectronics. - 0956-5663 .- 1873-4235. ; 17:5, s. 395-403
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Tidskriftsartikel (refereegranskat)abstract
- The detection of bacterial infections in a mammalian cell culture process is realised using a gas sensor array. In production-scale and laboratory-scale cultivations of a perfused recombinant CHO-cell culture producing human blood coagulation Factor VIII, we show that the gas sensor array identifies bacterial contamination earlier than conventional methods. The sensitivity of the instrument is verified by inoculation of a blank cell culture medium with defined bacterial cell counts. © 2002 Elsevier Science B.V. All rights reserved.
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| 12. |
- Bachinger, T., et al.
(författare)
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Monitoring cellular state transitions in a production-scale CHO-cell process using an electronic nose
- 2000
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Ingår i: Journal of Biotechnology. - 0168-1656 .- 1873-4863. ; 76:1, s. 61-71
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Tidskriftsartikel (refereegranskat)abstract
- An electronic nose is used to monitor the bioreactor off-gas composition in perfused cultivations of a CHO-cell line producing recombinant human blood coagulation factor VIII. The applicability of the electronic nose for monitoring cellular state transitions and process control is explained. It is shown that the instrument can reveal characteristic process states related to product and lactate formation, and detect microbial infections in a very early stage of the infection. The visualization of ideal process conditions is realized by using principal component analysis (PCA) and the on-line applicability of this method is outlined. The results illustrate the potential of the electronic nose as on-line sensor for ensuring product and process quality in production-scale bioprocesses. Copyright (C) 2000 Elsevier Science B.V.An electronic nose is used to monitor the bioreactor off-gas composition in perfused cultivations of a CHO-cell line producing recombinant human blood coagulation factor VIII. The applicability of the electronic nose for monitoring cellular state transitions and process control is explained. It is shown that the instrument can reveal characteristic process states related to product and lactate formation, and detect microbial infections in a very early stage of the infection. The visualization of ideal process conditions is realized by using principal component analysis (PCA) and the on-line applicability of this method is outlined. The results illustrate the potential of the electronic nose as on-line sensor for ensuring product and process quality in production-scale bioprocesses.
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| 13. |
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| 14. |
- Bachinger, T., et al.
(författare)
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Physiologically motivated monitoring of fermentation processes by means of an electronic nose
- 2001
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Ingår i: Chemical Engineering & Technology. - 0930-7516 .- 1521-4125. ; 24:7, s. 33-42
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Tidskriftsartikel (refereegranskat)abstract
- An on-line approach of non-invasive monitoring of the physiological changes in fermentation processes is presented. In yeast batch and bacterial fed-batch fermentations it is shown that metabolic state changes can be revealed using an electronic nose. The transient responses of the gas sensors to the changes in the composition of the volatiles emitted from the cell cultures during fermentation are used to retrieve a semi-quantitative representation of the physiological state of the cultures. With the sensor responses of the electronic nose it is shown that physiological variables such as rates of growth, substrate uptake and product formation can be depicted. The non-invasive method thus seems as a pertinent alternative to conventional bioreactor monitoring methods.
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| 15. |
- Bachinger, Th, et al.
(författare)
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Searching for process information in the aroma of cell cultures
- 2000
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Ingår i: Trends in Biotechnology. - 0167-7799 .- 1879-3096. ; 18:12, s. 494-500
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Tidskriftsartikel (refereegranskat)abstract
- Aroma emissions from living cells can provide valuable information about the metabolic and physiological condition of those cells. Electronic noses are chemical gas-sensor arrays that use artificial neural network models to evaluate aromas. They can interpret the complex aroma information emitted from cultures of bacteria, yeast cells and animal cells. Potential applications for electronic noses range from medical diagnosis to industrial bioprocessing. Copyright (C) 2000 Elsevier Science Ltd.
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| 16. |
- Bengtsson, Katarina, 1985-, et al.
(författare)
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A clip-on electroosmotic pump for oscillating flow in microfluidic cell culture devices
- 2018
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Ingår i: Microfluidics and Nanofluidics. - : Springer Berlin/Heidelberg. - 1613-4982 .- 1613-4990. ; 22:3
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Tidskriftsartikel (refereegranskat)abstract
- Recent advances in microfluidic devices put a high demand on small, robust and reliable pumps suitable for high-throughput applications. Here we demonstrate a compact, low-cost, directly attachable (clip-on) electroosmotic pump that couples with standard Luer connectors on a microfluidic device. The pump is easy to make and consists of a porous polycarbonate membrane and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) electrodes. The soft electrode and membrane materials make it possible to incorporate the pump into a standard syringe filter holder, which in turn can be attached to commercial chips. The pump is less than half the size of the microscope slide used for many commercial lab-on-a-chip devices, meaning that these pumps can be used to control fluid flow in individual reactors in highly parallelized chemistry and biology experiments. Flow rates at various electric current and device dimensions are reported. We demonstrate the feasibility and safety of the pump for biological experiments by exposing endothelial cells to oscillating shear stress (up to 5 dyn/cm2) and by controlling the movement of both micro- and macroparticles, generating steady or oscillatory flow rates up to ± 400 μL/min.
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| 17. |
- Bergström, Gunnar, et al.
(författare)
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Capacitive biosensor for detection of toxicity biomarkers
- 2015
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Microfluidic devices are rapidly gaining importance for in vitro toxicity testing. Biomarker detection in microfluidic assays are however challenging due to small sample sizes and low analyte concentration. Capacitive electrochemical biosensors have been reported to have high sensitivity and properties that are amenable for implementation into microfluidic devices.In this work a biosensor application for troponin T (TnT) is presented. The sensor showed linear response to analyte over five orders of magnitude with the lowest detectable signal at 10-13 M. The sensor proved to be able to detect TnT spiked in cell culture media at concentrations relevant for cell cultures.
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| 18. |
- Bergström, Gunnar
(författare)
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Exploring the SPR methodology for monitoring of critical attributes in toxicity testing and bioproduction
- 2012
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Analysis of biological components is central in bioprocess monitoring, process control, product quality control and cell based toxicity assaying. One of these themes that is pursued in this thesis is the use of biosensors for monitoring of molecular markers, exploiting the natural selectivity of biomolecules. Another is the use of glycoconjugates to monitor the activity of biomolecules in a flu vaccine process is studied and were the sensor is based on the concept of weak affinity giving fast response time for the sensor.A third theme is monitoring of cell cultures used for toxicity testing different protein markers is of interest.When developing biosensor surfaces for new antigens commercial preparations of antibodies are often used. In this work we have chosen to look at lactate dehydrogenase (LDH) and describe the preparation and characterisation of antibody used in biosensor surface development.The design of a sensor surface is important for the characteristics of a sensor. By binding antibodies in an oriented manner to the surface a better control of the properties of the antibodies is achieved. The demonstrated method also has the advantage of in situ purification and provides a flexible platform for antibody evaluation and sensor development.In one sentence this thesis explores the possibility of utilizing recognition elements of a biosensor surface. In particular, surface plasmon resonance (SPR) is used as the primary biosensing tool, however most findings in are relevant for other biosensors.Moreover, the thesis approaches existing bioanalytical impediments, such as purity and accessibility of the recognition elements on the sensor surface and preparation strategies to achieve this.
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| 19. |
- Bergström, Gunnar, et al.
(författare)
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Initial development towards in vitro toxicity assay for lactate dehydrogenase using surface plasmon resonance
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Work with initial development towards in vitro toxicity assay for lactate dehydrogenase (LDH) using surface plasmon resonance is described. LDH is one of the important versatile biomarkers in in vitro hepatotoxicity. In this report LDH is detected by surface plasmon resonance using antibodies directly immobilized to the sensor surface. The assay is further extended with protein G immobilized to the surface to capture the antibody ligand. This has the advantage of simultaneously and on site purify and orient antibody ligand.
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| 20. |
- Bergström, Gunnar, et al.
(författare)
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Macroporous microcarriers for introducing cells into a microfluidic chip
- 2014
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Ingår i: Lab on a Chip. - : Royal Society of Chemistry. - 1473-0197 .- 1473-0189. ; 14:18, s. 3502-3504
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Tidskriftsartikel (refereegranskat)abstract
- Macroporous gelatin beads (CultiSpher™ microcarriers) provide a convenient method for rapidly and reliably introducing cells cultured ex situ into a microfluidic device, where the spheres create a 3D environment for continued cell proliferation. We demonstrate the usefulness of this technique with a proof-of-concept viability analysis of cardiac cells after treatment with doxorubicin. © 2014 the Partner Organisations.
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| 21. |
- Bergström, Gunnar
(författare)
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Microfluidic biosensor systems for cardiotoxicity assaying
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Toxicity screening is an important part of pharmaceutical development and early detection of toxic side effects provide the opportunity for early redesign or termination of unfeasible projects. Today toxicity testing is relying on experiments on animals. Ethical concerns, high costs and problems with interspecies variability in animal experiments have introduced incentives for cell-based toxicity assays. The recent development of stem cell technology have raised the hope for toxicity testing with higher predictivity that can reduce the amount of animals sacrificed, increase the patient safety and reduce the costs in pharmaceutical development.Cell development and behavior is to a large extent dependent on the microenvironment. Microfluidic techniques can be used to build small-sized structures that provide the opportunity to introduce a high degree of control of the cell culture environment with features in cell sizes. In this thesis is demonstrated two different methods for infusing cells into microfluidic cell culture devices using either cells clustered in cardiac bodies during differentiation or cells pre-seeded in microporous carriers prior to infusion.Microfluidic cell culture devices are well suited for optical evaluation. Demonstrated in this thesis is fluorescent staining in combination with confocal microscopy as well as automated imaging with evaluation of beating frequency of cardiomyocyte cell clusters can be used to assess toxicity of cells cultured in microfluidic devices.Biosensors use biological recognition elements to measure the presence of a chemical substance, for example low concentrations of biomarkers secreted by cells in a toxicity assay. Especially capacitive biosensors have shown very low limit of detection. In addition, protein G is demonstrated as an affinity ligand to capture IgG antibodies used as recognition element in a biosensor application or used for antibody screening.
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| 22. |
- Bergström, Gunnar, et al.
(författare)
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Orientation and capturing of antibody affinity ligands: Applications to surface plasmon resonance biochips
- 2011
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 158:1, s. 265-270
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Tidskriftsartikel (refereegranskat)abstract
- A surface plasmon resonance (SPR) sensor chip with immobilized protein G was used for simultaneously capturing, purifying and orienting antibody ligands. The ligands were further stabilized by chemical cross-linking. This procedure of designing the sensor chip improved efficient use of the ligands and could prolong the analytical use. less thanbrgreater than less thanbrgreater thanThe procedure was evaluated on standard dextran-coated sensor chips onto which commercial semi-purified antibodies towards human serum albumin and human troponin where captured and used for analysing their antigens. less thanbrgreater than less thanbrgreater thanThe procedure demonstrates a general design approach for presenting the biorecognition element on a biosensor surface which enhances sensitivity, stability and selectivity at the same time as an impure ligand is purified.
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| 23. |
- Bergström, Gunnar, et al.
(författare)
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Stem cell derived in vivo-like human cardiac bodies in a microfluidic device for toxicity testing by beating frequency imaging
- 2015
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Ingår i: Lab on a Chip. - : Royal Society of Chemistry. - 1473-0197 .- 1473-0189. ; 15:15, s. 3242-3249
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Tidskriftsartikel (refereegranskat)abstract
- Beating in vivo-like human cardiac bodies (CBs) were used in a microfluidic device for testing cardiotoxicity. The CBs, cardiomyocyte cell clusters derived from induced pluripotent stem cells, exhibited typical structural and functional properties of the native human myocardium. The CBs were captured in niches along a perfusion channel in the device. Video imaging was utilized for automatic monitoring of the beating frequency of each individual CB. The device allowed assessment of cardiotoxic effects on the 3D clustered cardiomyocytes from the drug substances doxorubicin, verapamil and quinidine. Beating frequency data recorded over a period of 6 hours are presented and compared to literature data. The results indicate that this microfluidic setup with imaging of CB characteristics provides a new opportunity for label-free, non-invasive investigation of toxic effects in a 3D microenvironment.
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| 24. |
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Bioreactors : design, operation and novel applications
- 2016
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Samlingsverk (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- In this expert handbook both the topics and contributors are selected so as to provide an authoritative view of possible applications for this new technology. The result is an up-to-date survey of current challenges and opportunities in the design and operation of bioreactors for high-value products in the biomedical and chemical industries.Combining theory and practice, the authors explain such leading-edge technologies as single-use bioreactors, bioreactor simulators, and soft sensor monitoring, and discuss novel applications, such as stem cell production, process development, and multi-product reactors, using case studies from academia as well as from industry. A final section addresses the latest trends, including culture media design and systems biotechnology, which are expected to have an increasing impact on bioreactor design.With its focus on cutting-edge technologies and discussions of future developments, this handbook will remain an invaluable reference for many years to come.
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| 25. |
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