1,720,971 research outputs found
sj-pdf-1-tej-10.1177_20417314221103042 – Supplemental material for A gastruloid model of the interaction between embryonic and extra-embryonic cell types
No full textSupplemental material, sj-pdf-1-tej-10.1177_20417314221103042 for A gastruloid model of the interaction between embryonic and extra-embryonic cell types by Noémie MLP Bérenger-Currias, Maria Mircea, Esmée Adegeest, Patrick R van den Berg, Marleen Feliksik, Mazène Hochane, Timon Idema, Sander J Tans and Stefan Semrau in Journal of Tissue Engineering</p
sj-docx-2-tej-10.1177_20417314221103042 – Supplemental material for A gastruloid model of the interaction between embryonic and extra-embryonic cell types
No full textSupplemental material, sj-docx-2-tej-10.1177_20417314221103042 for A gastruloid model of the interaction between embryonic and extra-embryonic cell types by Noémie MLP Bérenger-Currias, Maria Mircea, Esmée Adegeest, Patrick R van den Berg, Marleen Feliksik, Mazène Hochane, Timon Idema, Sander J Tans and Stefan Semrau in Journal of Tissue Engineering</p
Interactions between model inclusions on closed lipid bilayer membranes
Full text linkProtein inclusions in the membranes of living cells interact via the deformations they impose on that membrane. Such membrane-mediated interactions lead to sorting and self-assembly of the inclusions, as well as to membrane remodelling, crucial for many biological processes. For the past decades, theory, numerical calculations and experiments have been using simplified models for proteins to gain quantitative insights into their behaviour. Despite challenges arising from nonlinearities in the equations, the multiple length scales involved and the nonadditive nature of the interactions, recent progress now enables for the first time a direct comparison between theoretical and numerical predictions and experiments. We review the current knowledge on the biologically most relevant case, inclusions on lipid membranes with a closed surface and discuss challenges and opportunities for further progress.Accepted Author ManuscriptBN/Timon Idema La
Mechanics and Relativity
No full textIn Mechanics and Relativity, the reader is taken on a tour through time and space. Starting from the basic axioms formulated by Newton and Einstein, the theory of motion at both the everyday and the highly relativistic level is developed without the need of prior knowledge. The relevant mathematics is provided in an appendix. The text contains various worked examples and a large number of original problems to help the reader develop an intuition for the physics. Applications covered in the book span a wide range of physical phenomena, including rocket motion, spinning tennis rackets and high-energy particle collisions.TU Delft OPEN TextbookBN/Timon Idema La
Printing of Patterned, Engineered E. coli Biofilms with a Low-Cost 3D Printer
No full textBiofilms can grow on virtually any surface available, with impacts ranging from endangering the lives of patients to degrading unwanted water contaminants. Biofilm research is challenging due to the high degree of biofilm heterogeneity. A method for the production of standardized, reproducible, and patterned biofilm-inspired materials could be a boon for biofilm research and allow for completely new engineering applications. Here, we present such a method, combining 3D printing with genetic engineering. We prototyped a low-cost 3D printer that prints bioink, a suspension of bacteria in a solution of alginate that solidifies on a calcium-containing substrate. We 3D-printed Escherichia coli in different shapes and in discrete layers, after which the cells survived in the printing matrix for at least 1 week. When printed bacteria were induced to form curli fibers, the major proteinaceous extracellular component of E. coli biofilms, they remained adherent to the printing substrate and stably spatially patterned even after treatment with a matrix-dissolving agent, indicating that a biofilm-mimicking structure had formed. This work is the first demonstration of patterned, biofilm-inspired living materials that are produced by genetic control over curli formation in combination with spatial control by 3D printing. These materials could be used as living, functional materials in applications such as water filtration, metal ion sequestration, or civil engineering, and potentially as standardizable models for certain curli-containing biofilms.Accepted Author ManuscriptBN/Marie-Eve Aubin-Tam LabBN/Timon Idema LabBN/Anne Meyer La
Membrane area gain and loss during cytokinesis
No full textIn cytokinesis of animal cells, the cell is symmetrically divided into two. Since the cell's volume is conserved, the projected area has to increase to allow for the change of shape. Here we aim to predict how membrane gain and loss adapt during cytokinesis. We work with a kinetic model in which membrane turnover depends on membrane tension and cell shape. We apply this model to a series of calculated vesicle shapes as a proxy for the shape of dividing cells. We find that the ratio of kinetic turnover parameters changes nonmonotonically with cell shape, determined by the dependence of exocytosis and endocytosis on membrane curvature. Our results imply that controlling membrane turnover will be crucial for the successful division of artificial cells.BN/Timon Idema La
More than just a barrier: using physical models to couple membrane shape to cell function
No full textThe correct execution of many cellular processes, such as division and motility, requires the cell to adopt a specific shape. Physically, these shapes are determined by the interplay of the plasma membrane and internal cellular driving factors. While the plasma membrane defines the boundary of the cell, processes inside the cell can result in the generation of forces that deform the membrane. These processes include protein binding, the assembly of protein superstructures, and the growth and contraction of cytoskeletal networks. Due to the complexity of the cell, relating observed membrane deformations back to internal processes is a challenging problem. Here, we review cell shape changes in endocytosis, cell adhesion, cell migration and cell division and discuss how by modeling membrane deformations we can investigate the inner working principles of the cell.BN/Timon Idema La
Mechanics in biology
No full textMechanics plays a key role in life, from simple tasks like providing protective shielding to highly complex ones such as cell division. To understand mechanical properties on the organism level, we need to zoom in to its constituent cells, then zoom back out to see how they collectively build tissues
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