The Experts below are selected from a list of 69 Experts worldwide ranked by ideXlab platform
Nancy L. Allbritton - One of the best experts on this subject based on the ideXlab platform.
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Microstrainer array for the capture and culture of colonic stem-cells
2014Co-Authors: Asad Ahmad, Yuli Wang, Christopher E. Sims, Nancy L. AllbrittonAbstract:A microdevice was developed to linearly array colon crypts to assay the impact of Wnt-3a on colonic cells. Crypts were isolated from a transgenic mouse and then cultured in the device under a Wnt-3a gradient. 69 ± 8% of total stem-cell activity as measured by Sox9eGFP + fluorescence was present in colonoid regions nearest the source. Under homogenous Wnt-3a growth conditions, only 46± 8% of total stem-cell activity existed in regions nearest the source. Under a Wnt-3a gradient, colonoids were displayed polarized growth with high stem-cell activity near the source and low stem-cell activity near the sink.
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Capture and 3D culture of colonic crypts and colonoids in a microarray platform
Lab on a chip, 2013Co-Authors: Yuli Wang, Asad Ahmad, Pavak K. Shah, Christopher E. Sims, Scott T. Magness, Nancy L. AllbrittonAbstract:Crypts are the basic structural and functional units of colonic epithelium and can be isolated from the colon and cultured in vitro into multi-cell spheroids termed “colonoids”. Both crypts and colonoids are ideal building blocks for construction of an in vitro tissue model of the colon. Here we proposed and tested a microengineered platform for capture and in vitro 3D culture of colonic crypts and colonoids. An integrated platform was fabricated from polydimethylsiloxane which contained two fluidic layers separated by an array of cylindrical microwells (150 μm diameter, 150 μm depth) with perforated bottoms (30 μm opening, 10 μm depth) termed “Microstrainers”. As fluid moved through the array, crypts or colonoids were retained in the Microstrainers with a >90% array-filling efficiency. Matrigel as an extracellular matrix was then applied to the Microstrainers to generate isolated Matrigel pockets encapsulating the crypts or colonoids. After supplying the essential growth factors, epidermal growth factor, Wnt-3A, R-spondin 2 and noggin, 63 ± 13% of the crypts and 77 ± 8% of the colonoids cultured in the Microstrainers over a 48–72 h period formed viable 3D colonoids. Thus colonoid growth on the array was similar to that under standard culture conditions (78 ± 5%). Additionally the colonoids displayed the same morphology and similar numbers of stem and progenitor cells as those under standard culture conditions. Immunofluorescence staining confirmed that the differentiated cell-types of the colon, goblet cells, enteroendocrine cells and absorptive enterocytes, formed on the array. To demonstrating the utility of the array in tracking the colonoid fate, quantitative fluorescence analysis was performed on the arrayed colonoids exposed to reagents such as Wnt-3A and the γ-secretase inhibitor LY-411575. The successful formation of viable, multi-cell type colonic tissue on the microengineered platform represents a first step in the building of a “colon-on-a-chip” with the goal of producing the physiologic structure and organ-level function of the colon for controlled experiments.
Koenraad Muylaert - One of the best experts on this subject based on the ideXlab platform.
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Influence of culture medium recycling on the performance of Arthrospira platensis cultures
Algal Research - Biomass Biofuels and Bioproducts, 2015Co-Authors: Orily Depraetere, Imogen Foubert, Guillaume Pierre, Wim Noppe, Dries Vandamme, Philippe Michaud, Koenraad MuylaertAbstract:To reduce the water footprint of microalgae biomass production, it is essential to recycle the culture medium. The influence of medium recycling on the performance of the cyanobacterium Arthrospira platensis, the most widely cultivated microalgae, was investigated. Arthrospira was harvested with a 20 μm mesh size microstrainer, which is the benchmark harvesting technology for Arthrospira production. Repeated recycling of the culture medium resulted in a decline in growth rate and the maximum quantum yield of photosynthesis (Fv/Fm) when compared to a control culture in fresh medium. This decline was accompanied by accumulation of organic matter in the culture medium (up to 104 mg C L− 1). This organic matter consists of 70% of sugars, mostly rhamnose-rich polysaccharides with uronic acids. Accumulation of polysaccharides resulted in a decrease in the filtration rate through the microstrainer used for harvesting. Part of the biomass escaped harvesting and was returned to the culture with the recycled medium. This resulted in a change in the Arthrospira population and reduction in the harvesting efficiency, but this change in population had no effect on the growth rate. The growth rate of Arthrospira in the recycled culture medium was primarily influenced by organic matter that accumulated in the medium.
Yuli Wang - One of the best experts on this subject based on the ideXlab platform.
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Microstrainer array for the capture and culture of colonic stem-cells
2014Co-Authors: Asad Ahmad, Yuli Wang, Christopher E. Sims, Nancy L. AllbrittonAbstract:A microdevice was developed to linearly array colon crypts to assay the impact of Wnt-3a on colonic cells. Crypts were isolated from a transgenic mouse and then cultured in the device under a Wnt-3a gradient. 69 ± 8% of total stem-cell activity as measured by Sox9eGFP + fluorescence was present in colonoid regions nearest the source. Under homogenous Wnt-3a growth conditions, only 46± 8% of total stem-cell activity existed in regions nearest the source. Under a Wnt-3a gradient, colonoids were displayed polarized growth with high stem-cell activity near the source and low stem-cell activity near the sink.
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Capture and 3D culture of colonic crypts and colonoids in a microarray platform
Lab on a chip, 2013Co-Authors: Yuli Wang, Asad Ahmad, Pavak K. Shah, Christopher E. Sims, Scott T. Magness, Nancy L. AllbrittonAbstract:Crypts are the basic structural and functional units of colonic epithelium and can be isolated from the colon and cultured in vitro into multi-cell spheroids termed “colonoids”. Both crypts and colonoids are ideal building blocks for construction of an in vitro tissue model of the colon. Here we proposed and tested a microengineered platform for capture and in vitro 3D culture of colonic crypts and colonoids. An integrated platform was fabricated from polydimethylsiloxane which contained two fluidic layers separated by an array of cylindrical microwells (150 μm diameter, 150 μm depth) with perforated bottoms (30 μm opening, 10 μm depth) termed “Microstrainers”. As fluid moved through the array, crypts or colonoids were retained in the Microstrainers with a >90% array-filling efficiency. Matrigel as an extracellular matrix was then applied to the Microstrainers to generate isolated Matrigel pockets encapsulating the crypts or colonoids. After supplying the essential growth factors, epidermal growth factor, Wnt-3A, R-spondin 2 and noggin, 63 ± 13% of the crypts and 77 ± 8% of the colonoids cultured in the Microstrainers over a 48–72 h period formed viable 3D colonoids. Thus colonoid growth on the array was similar to that under standard culture conditions (78 ± 5%). Additionally the colonoids displayed the same morphology and similar numbers of stem and progenitor cells as those under standard culture conditions. Immunofluorescence staining confirmed that the differentiated cell-types of the colon, goblet cells, enteroendocrine cells and absorptive enterocytes, formed on the array. To demonstrating the utility of the array in tracking the colonoid fate, quantitative fluorescence analysis was performed on the arrayed colonoids exposed to reagents such as Wnt-3A and the γ-secretase inhibitor LY-411575. The successful formation of viable, multi-cell type colonic tissue on the microengineered platform represents a first step in the building of a “colon-on-a-chip” with the goal of producing the physiologic structure and organ-level function of the colon for controlled experiments.
M. Piontek - One of the best experts on this subject based on the ideXlab platform.
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The Efficiency of Microstrainers Filtration in the Process of Removing Phytoplankton with Special Consideration of Cyanobacteria.
Toxins, 2019Co-Authors: Wanda Czyżewska, M. PiontekAbstract:The research presented in this manuscript concerns the evaluation of the effectiveness of Microstrainers, which are designed to reduce the amount of plankton in treated surface water. The efficiency of microstrainer filtration analysis is very important for the proper course of the water-treatment process not only in the Water-Treatment Plant (WTP) in Zielona Gora (central western Poland) but also in other WTPs around the world. The qualitative and quantitative monitoring of the abundance of plankton including cyanobacteria during the particle-filtration process allows not only for the assessment of the potential cyanotoxic risk in surface water providing a source of drinking water, but also allows the evaluation of the action and the prevention of adverse impacts of Microstrainers. Over four years of research, it was observed that the largest amount of cyanobacteria before microstrainer filtration took place in May. The dominant species was Limnothrix redeckei. The microstrainer removal of plankton and cyanobacteria was statistically significant. The quantity of removed plankton increased with its increasing content in raw water. The particle-filtration process, by reducing the amount of cyanobacteria, contributes to a decrease in intracellular microcystins.
Orily Depraetere - One of the best experts on this subject based on the ideXlab platform.
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Influence of culture medium recycling on the performance of Arthrospira platensis cultures
Algal Research - Biomass Biofuels and Bioproducts, 2015Co-Authors: Orily Depraetere, Imogen Foubert, Guillaume Pierre, Wim Noppe, Dries Vandamme, Philippe Michaud, Koenraad MuylaertAbstract:To reduce the water footprint of microalgae biomass production, it is essential to recycle the culture medium. The influence of medium recycling on the performance of the cyanobacterium Arthrospira platensis, the most widely cultivated microalgae, was investigated. Arthrospira was harvested with a 20 μm mesh size microstrainer, which is the benchmark harvesting technology for Arthrospira production. Repeated recycling of the culture medium resulted in a decline in growth rate and the maximum quantum yield of photosynthesis (Fv/Fm) when compared to a control culture in fresh medium. This decline was accompanied by accumulation of organic matter in the culture medium (up to 104 mg C L− 1). This organic matter consists of 70% of sugars, mostly rhamnose-rich polysaccharides with uronic acids. Accumulation of polysaccharides resulted in a decrease in the filtration rate through the microstrainer used for harvesting. Part of the biomass escaped harvesting and was returned to the culture with the recycled medium. This resulted in a change in the Arthrospira population and reduction in the harvesting efficiency, but this change in population had no effect on the growth rate. The growth rate of Arthrospira in the recycled culture medium was primarily influenced by organic matter that accumulated in the medium.