Dr Margarita Staykova
(email at email@example.com)
PhD position with a starting date October 2014!
I look for motivated students with interests in biophysics and soft matter, readiness to work on multidisciplinary projects, and a high quality degree in physics, chemistry, biology or a relevant discipline.
Description of the research activity in the group is given below. Please contact me directly for more information.
I finished my undergraduate studies in Biophysics at the University of Sofia, Bulgaria. Shortly after, I went to Germany on a DAAD fellowship to do my PhD with Prof. J. Gimsa at the University of Rostock, where I graduated in 2006. During that time I studied theoretically the interaction of high frequency electromagnetic fields with cellular media, and in particular with lipid membranes. As a postdoc in the group of Dr. R. Dimova at the Max Planck Institute of Colloids and Interfaces (Germany) I switched to an experimental project on the electro-manipulation of lipid vesicles. In 2009, I moved to Princeton University to the Complex Fluid Group of Prof. Howard A. Stone, where I laid the foundation of my current research on the biophysics of biological membranes. Since October 2013 I am working as a lecturer in the departments of Physics and Chemistry at Durham University.
- Biological membranes
- Functional interfaces
- Mechanical and electric manipulation of lipid membranes
This is a newly formed group in soft matter, whose objectives are to understand the functional principles of biological membranes and capture them in artificially designed smart interfaces. We use engineering approaches and optical tools for quantitative measurements. We are part of the Biophysical Sciences Institute and the Durham Center for Soft Matter.
Currently our efforts are focused on elucidating the mechano-sensitive architecture and composition of the cell interface.
Cell interface- the crosstalk between structures
The cell interface is a multilayered ensemble, with the plasma membrane in the middle, the contractile actin cortex on the inner side, and an extracellular matrix or a cell wall, on the outer side. In this project we study how the coupling between these structurally and mechanically different layers shape the surface functionality of cells. For example, we were recently able to demonstrate that a lipid membrane coupled to an elastic substrate expels or absorbs reversibly lipid protrusions in response to changes in the substrate area, providing us with mechanical insights on how cells regulate their surface area (see Staykova et al., PRL13 and PNAS11- see picture on the right). Our goal is to build a realistic model of the cell interface, which explains the wrinkling, buckling, budding, tubulation and other vital forms of membrane deformation.
Molecular principles of membrane mechano-transductuion
It becomes apparent that the surface tension of biological membranes is a key regulator of numerous physiological processes in cells, like membrane traffic, cell motility, surface area regulation, etc. Tension arises from physical stresses both internal (from the cytoskeleton) and external acting on the membrane, and also from biochemically induced stresses from the binding of proteins or the insertion of small molecules into the membranes.
To understand the mechano-sensitivity of biological membranes we engineer devices that would allow us to apply well-defined mechanical stresses to model membranes of particular composition. Our goal is to relate the large-scale membrane deformations to changes on the molecular level, i.e. lipid packing, polysaccharide conformation, molecular adhesion and insertion.
Lipid bilayers flow
Lipid bilayers are expected to behave as two-dimeniosnla fluids, given their negligible thickness and in-plane shear viscosity. Indeed, it has been shown that vesicles or cells connected by lipid tethers exchange membrane material by lipid flow when under different tension. In this project we study the flow of membranes under external forces. We have visualized a pronounced flow on lipid vesicles subject to nonhomogeneous AC electric fields (image- Staykova et al.,Soft matter 08). We explore how the flow pattern and velocity depend on the geometries of the lipid membrane (spherical vs planar) and the external force field.
- Centre for Materials Physics
- Condensed Matter Physics
Journal papers: academic
- Staykova, M. , Arroyo, M. Rahimi, M. & Stone, H.A. (2013). Confined bilayers passively regulate shape and stress . Physical Review Letters 110(2): 028101.
- Staykova, M. , Holmes, D.P. Read, C. & Stone, H.A. (2011). Mechanics of surface area regulation in cells examined with confined lipid membranes. Proceedings of the National Academy of Sciences 108(22): 9084–9088.
- Knorr, R.L. Staykova, M. , Gracija, R.S. & Dimova, R. (2010). Wrinkling and electroporation of giant vesicles in the gel phase. Soft Matter 6(9): 1990-1996.
- Dimova R., Bezlyepkina, N. Jordö, M. Knorr, R. Riske, K. Staykova, M., Vlahovska, P., Yamamoto, T., Yang, P. & Lipowsky, R. (2009). Vesicles in electric fields: Some novel aspects of membrane behavior. Soft Matter 5(17): 3201-3212.
- Staykova M., Lipowsky R. & Dimova R. (2008). Membrane flow patterns in multicomponent giant vesicles induced by alternating electric fields. Soft Matter 4(11): 2168.
- Simeonova, M. & Gimsa, J. (2006). The influence of the molecular structure of lipid membranes on the electric field distribution and energy absorption. Bioelectromagnetics 27(8): 652.
- Simeonova, M. & Gimsa, J. (2005). Dielectric anisotropy, volume potential anomalies and the persistent Maxwellian equivalent body. Journal of Physics: Condensed Matter 17(50): 7817.
- Simeonova, M., Wachner, D. & Gimsa, J. (2002). Cellular absorption of electric field energy: influence of molecular properties of the cytoplasm. Bioelectrochemistry 56(1-2): 215.
- Wachner, D., Simeonova, M. & Gimsa, J. (2002). Estimating the subcellular absorption of electric field energy: equations for an ellipsoidal single shell model. Bioelectrochemistry 56(1-2): 211.