Microfluidics platform for measurement of volume changes in immobilized intestinal enteroids

Intestinal enteroids are ex vivo primary cultured single-layer epithelial cell spheroids of average diameter ∼150 μm with luminal surface facing inward. Measurement of enteroid swelling in response to secretagogues has been applied to genetic testing in cystic fibrosis and evaluation of drug candidates for cystic fibrosis and secretory diarrheas. The current measurement method involves manual addition of drugs and solutions to enteroids embedded in a Matrigel matrix and estimation of volume changes from confocal images of fluorescently stained enteroids. We developed a microfluidics platform for efficient trapping and immobilization of enteroids for quantitative measurement of volume changes. Multiple enteroids are trapped in a “pinball machine-like” array of polydimethylsiloxane posts for measurement of volume changes in unlabeled enteroids by imaging of an extracellular, high-molecular weight fluorescent dye. Measurement accuracy was validated using slowly expanding air bubbles. The method was applied to measure swelling of mouse jejunal enteroids in response to an osmotic challenge and cholera toxin-induced chloride secretion. The microfluidics platform allows for parallel measurement of volume changes on multiple enteroids during continuous superfusion, without an immobilizing matrix, and for quantitative volume determination without chemical labeling or assumptions about enteroid shape changes during swelling.     

Welche bildungswissenschaftlichen Inhalte sind wichtig in der Lehrerbildung?

In reviews of university teacher training, the parts of the curriculum based on educational science are often criticized as missing practical relevance and being non-cumulative. At the same time, uncertainty exists regarding which educational science based content is important for teacher candidates. The objective of the Delphi study presented here was the identification of core educational science content in university training. To this aim, a survey was carried out amongst 49 experts from different subject areas and phases of teacher training in three rounds using a standardized questionnaire. In the first round, 213 topics were specified, which were then assessed by experts regarding their importance for various aspects of the teaching profession. In the second and third rounds, which had the objective of reducing the number of topics, the experts chose a limited number of topics based on their relevance for university teacher training and for the practical success of teaching itself. The results show that the original list was comprehensive and that there is a consensus among most of the experts on their respective importance for teaching training.