Engineering synthetic materials that mimic the remarkable complexity of living organisms is a fundamental challenge in science and technology. We studied the spatiotemporal patterns that emerge when an active nematic More info
film of microtubules and molecular motors is encapsulated within a shape-changing lipid vesicle. Unlike in equilibrium systems, where defects are largely static structures, in active nematics defects move spontaneously and can be described as self-propelled particles. The combination of activity, topological constraints, and vesicle deformability produces a myriad of dynamical states. We highlight two dynamical modes: a tunable periodic state that oscillates between two defect configurations, and shape-changing vesicles with streaming filopodia-like protrusions. These results demonstrate how biomimetic materials can be obtained when topological constraints are used to control the non-equilibrium dynamics of active matter.
Keber FC, Loiseau E, Sanchez T, DeCamp SJ, Giomi L, Bowick MJ, Marchetti MC, Dogic Z, Bausch AR. Science (2014) 345:1135-9.
QUBIC, the QU Bolometric Interferometer for Cosmology
Jean-Christophe Hamilton from APC Paris will be visiting next week for a colloquium about QUBIC. This may be of interest to the astronomy community and Dorothea Samtleben has scheduled the More info
talk for the 17th of September in room 414 at 11:30
Publ. 17-09-2014 11:30
What is Quantum mechanics?
Carlo Beenakker will give a layman's talk on what quantum theory implies and what developments are taking place. More info Read more Publ. 15-09-2014 07:35
Designing Synthetic Virus Particles for Gene Therapy
Researchers from Wageningen UR, together with colleagues from the University of Leiden, Eindhoven University of Technology and Radboud University Nijmegen, have successfully developed an artificial virus. This virus can be More info
used for the delivery of future generations of pharmaceuticals by 'packaging' them and delivering them to diseased cells. Dr. Daniela Kraft of Leiden University and prof. dr. ir. Paul van der Schoot (TU/e) were responsible for the theoretical underpinning that led to the design of the synthetic protein. The scientists present their findings in an article published in Nature Nanotechnology on August 24th 2014.
Bringing large biomolecules such as DNA or RNA to a desired location poses a great challenge for new generations of pharmaceuticals. DNA for example cannot by itself enter cells, and is quickly degraded by enzymes.
Natural viruses are highly effective in transferring DNA or RNA into cells. They do this by encapsulating and protecting their genetic material (RNA or DNA) with proteins. Natural viruses therefore bear great potential for therapies, but a health risk remains, and scientists are therefore looking for harmless alternatives.
The inspiration for the research published in Nature Nanotechnology came from a theoretical model that describes the assembly of a natural virus, tobacco mosaic virus. Dr. Daniela Kraft of Leiden University and prof. dr. ir. Paul van der Schoot of TU Eindhoven recently developed this model together with prof. dr. Willem Kegel of Utrecht University. They investigated, how the natural virus achieves full protection of its genetic material. The crucial element for successful encapsulation is cooperativity, which ensures that the proteins help each other to bind to the genetic material.
The design of the novel synthetic protein, which the scientists now presented, incorporates a similar cooperative domain based on silk. The synthetic protein consists of natural proteins such as collagen and spontaneously encapsulates DNA to form artificial viruses. Despite its simplicity, the synthetic virus resembles in many ways its natural counterpart. For example, its assembly dynamics can be described with the theoretical model that inspired the design, and the protein coat efficiently protects the DNA and transfers it to cells.
The synthetic virus particles may be employed to bring new generations of medications such as DNA into diseased cells in a safe way, and thus be particularly useful for gene therapy.
Design and self-assembly of simple coat proteins for artificial viruses,
Hernandez-Garcia et al., Nature Nanotechnology, doi:10.1038/nnano.2014.169
(published online 24 August 2014)
Sachse R, Dondapati SK, Fenz SF, Schmidt T & Kubick S. (2014) Membrane protein synthesis in cell-free systems: From bio-mimetic systems to bio-membranes., FEBS Lett., 588, 2774-81. [Abstract][DOI][pdf]
Armando Hernandez-Garcia, Daniela J. Kraft, Anne F.J. Janssen, Paul H. H. Bomans, Nico A.J.M. Sommerdijk, Dominique M.E. Thies-Weesie, Marco E. Favretto, Roland Brock, Frits A. de Wolf, Marc W. T. Werten, Paul van der Schoot, Martien Cohen Stuart & Renko de Vries (2014) Design and self-assembly of simple coat proteins for artificial viruses, Nature Nanotechnology, 8, 9, 698–702. [DOI]
28 Oct, 14:00:00, C.J. Gorterzaal
Instituuts Raad (IR)
31 Oct, 16:00:00,
Van der Waals Colloquium Cancelled:
6 Nov, 10:00:00, 106 HL
Free Introduction Course Learn to work with COMSOL Multiphysics This course provides an introduction to multiphysics modeling and analyses using COMSOL Multiphysics. It is intended for people at the Leiden University only who would like to start working with the Details & Registration