Rumiana Dimova

Rumiana Dimova
Max Planck Institute of Colloids and Interfaces | MPIKG · Theory & Bio-Systems

PhD

About

286
Publications
50,998
Reads
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9,728
Citations
Citations since 2016
154 Research Items
6640 Citations
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201620172018201920202021202202004006008001,0001,200
201620172018201920202021202202004006008001,0001,200
Additional affiliations
January 2000 - present
Max-Planck-Institut für Kolloid- und Grenzflächenforschung
Position
  • Group Leader
January 1996 - present
Centre de Recherche Paul Pascal
Education
October 2011 - February 2012
Universität Potsdam
Field of study
May 1997 - November 1999

Publications

Publications (286)
Article
Full-text available
Knowledge of the material properties of membranes is crucial to understanding cell viability and physiology. A number of methods have been developed to probe membranes in vitro, utilizing the response of minimal biomimetic membrane models to an external perturbation. In this review, we focus on techniques employing giant unilamellar vesicles (GUVs)...
Preprint
Full-text available
The stiffness of biological membranes determines the work required by cellular machinery to form and dismantle vesicles and other lipidic shapes. Model membrane stiffness can be determined from the equilibrium distribution of giant unilamellar vesicle surface undulations observable by phase contrast microscopy. With two or more components, lateral...
Article
Full-text available
Building functional mimics of cell membranes is an important task toward the development of synthetic cells. So far, lipid and amphiphilic block copolymers are the most widely used amphiphiles with the bilayers by the former lacking stability while membranes by the latter are typically characterized by very slow dynamics. Herein, we introduce a new...
Article
Nicotinic acetylcholine receptors (nAChRs) are involved in a great range of physiological and pathological conditions. Since they are transmembrane proteins, they interact strongly with the lipids surrounding them. Thus, the plasma membrane composition and heterogeneity play an essential role for the correct nAChR function, on the one hand, and the...
Article
Closed lipid bilayers in the form of giant unilamellar vesicles (GUVs) are commonly used membrane models. Various methods have been developed to prepare GUVs, however it is unknown if all approaches yield membranes with the same elastic, electric, and rheological properties. Here, we combine flickering spectroscopy and electrodefomation of GUVs to...
Article
Full-text available
His-tagged molecules can be attached to lipid bilayers via certain anchor lipids, a method that has been widely used for the biofunctionalization of membranes and vesicles. To observe the membrane-bound molecules, it is useful to consider His-tagged molecules that are fluorescent as well. Here, we study two such molecules, green fluorescence protei...
Article
Using fast imaging microscopy, we investigate in detail the expansion of micron-sized pores occurring in individual electroporated giant unilamellar vesicles composed of the phospholipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). To infer pore dynamics on the electrodeformed and electropermeabilized vesicles, we develop a computationa...
Article
Full-text available
Azobenzene-based photochromic lipids are valuable probes for the analysis of ion channel–lipid interactions. Rapid photoisomerization of these molecules enables the analysis of lipid gating kinetics and provides information on lipid sensing. Thermal relaxation of the metastable cis conformation to the trans conformation of azobenzene photolipids is...
Preprint
Cells compartmentalize their components in liquid-like condensates, which can be reconstituted in vitro. Although these condensates interact with membrane-bound organelles, the potential of membrane remodeling and the underlying mechanisms are not well understood. Here, we demonstrate that interactions between protein condensates and membranes can...
Article
Cell membranes are highly asymmetric and their stability against poration is crucial for survival. We investigated the influence of membrane asymmetry on electroporation of giant unilamellar vesicles with membranes doped with GM1, a ganglioside asymmetrically enriched in the outer leaflet of neuronal cell membranes. Compared to symmetric membranes,...
Article
Polycyclic aromatic hydrocarbons (PAH) are ubiquitous persistent organic pollutants forming as byproducts in combustion processes. These compounds can become nitrated in the environment forming even more toxic nitro derivatives. Both PAHs and nitro-PAHs accumulate in the soils which can lead to the pollution of vast areas of arable land. The best m...
Article
Full-text available
Significance The discovery that amphiphilic polymers, similar to phospholipids, can self-assemble to vesicles has inspired numerous applications. For instance, these polymersomes are employed for drug delivery due to their increased chemical and mechanical stability. These polymers can be also mixed with lipids to form the so-called hybrid membrane...
Article
Full-text available
Back Cover: In article number 2100712 by Ivan Ivanov and co‐workers, a functionalized dimethicone, commercially used as emulsifier in cosmetics, self‐assembles into vesicles and even provides a suitable environment for membrane proteins. Upon vigorous agitation in the presence of physiological concentrations of salt, these vesicles continuously fus...
Preprint
Full-text available
The endosomal sorting complex required for transport (ESCRT) is a multi-protein complex involved in several membrane remodelling processes. Different approaches have been used to dissect the mechanism by which ESCRT proteins produce scission in the membranes. However, the underlying mechanisms generating the membrane deformations remain poorly unde...
Article
The endosomal sorting complex required for transport (ESCRT) machinery mediates membrane fission reactions that exhibit a different topology from that observed in clathrin-coated vesicles. In all of the ESCRT-mediated events, the nascent vesicle buds away from the cytosol. However, ESCRT proteins are able to act upon membranes with different geomet...
Article
Full-text available
The interactions between biomembranes and particles are key to many applications, but the lack of controllable model systems to study them limits the progress in their research. Here, we describe how Janus polystyrene microparticles, half coated with iron, can be partially engulfed by artificial cells, namely giant vesicles, with the goals to contr...
Preprint
Full-text available
His-tagged molecules can be attached to lipid bilayers via certain anchor lipids, a method that has been widely used for the biofunctionalization of membranes and vesicles. To measure the coverage by the membrane-bound molecules, it is useful to study molecules that are fluorescent as well. Here, we use two such molecules, green fluorescence protei...
Article
Full-text available
Viscosity is a key property of cell membranes that controls mobility of embedded proteins and membrane remodeling. Measuring it is challenging because existing approaches involve complex experimental designs and/or models, and the applicability of some is limited to specific systems and membrane compositions. As a result there is scarcity of system...
Article
Full-text available
Platelet adhesion and activation are mediated by integrin αIIbβ3 clustering, which is crucial for the hemostatic function of platelets. In an activated state, integrins provide the connection between the extracellular matrix and the actin cytoskeleton through a variety of cytoplasmic proteins, such as talin. Here, droplet‐based microfluidics is app...
Article
Full-text available
Molecular crowding is an inherent feature of cell interiors. Synthetic cells as provided by giant unilamellar vesicles (GUVs) encapsulating macromolecules (polyethylene-glycol and dextran) represent an excellent mimetic system to study membrane transformations associated with molecular crowding and protein condensation. Similarly to cells, such GUV...
Preprint
Full-text available
Cell membranes are highly asymmetric and their stability against poration is crucial for survival. We investigated the influence of membrane asymmetry on electroporation of giant unilamellar vesicles with membranes doped with GM1, a ganglioside asymmetrically enriched in the outer leaflet of neuronal cell membranes. Compared to symmetric membranes,...
Preprint
Full-text available
The interactions between biomembranes and particles are key to many applications, but the lack of controllable model systems to study them limits the progress in their research. Here, we describe how Janus polystyrene microparticles, half coated with iron, can be partially engulfed by artificial cells, namely giant vesicles, with the goals to contr...
Article
Full-text available
Motivation A reliable characterization of the membrane pore edge tension of single giant unilamellar vesicles (GUVs) requires the measurement of micrometer sized pores in hundreds to thousands of images. When manually performed, this procedure has shown to be extremely time-consuming and to generate inconsistent results among different users and im...
Article
Full-text available
Biological cells are contained by a fluid lipid bilayer (plasma membrane, PM) that allows for large deformations, often exceeding 50% of the apparent initial PM area. Isolated lipids self-organize into membranes, but are prone to rupture at small (<2–4%) area strains, which limits progress for synthetic reconstitution of cellular features. Here, it...
Article
Full-text available
Giant unilamellar vesicles serve as membrane models and primitive mockups of natural cells. With respect to the latter use, amphiphilic polymers can be used to replace phospholipids in order to introduce certain favorable properties, ultimately allowing for the creation of truly synthetic cells. These new properties also enable the employment of ne...
Article
Full-text available
A variety of artificial cells springs from the functionalization of liposomes with proteins. However, these models suffer from low durability without repair and replenishment mechanisms, which can be partly addressed by replacing the lipids with polymers. Yet natural membranes are also dynamically remodeled in multiple cellular processes. Here, we...
Preprint
Full-text available
Molecular crowding is an inherent feature of the cell interior. Synthetic cells as provided by giant unilamellar vesicles (GUVs) encapsulating macromolecules (polyethylene-glycol and dextran) represent an excellent mimetic system to study membrane transformations associated with molecular crowding and protein condensation. Similarly to cells, such...
Article
Membrane fission triggered by the endosomal sorting complex required for transport (ESCRT) is an important process observed in several pathogenic and non-pathogenic cellular events. From synthetic-biology viewpoint, ESCRT proteins represent an interesting machinery for the construction of cell mimetic sub-compartments produced by fission. Since the...
Article
We describe a facile method to simultaneously measure the bending rigidity and capacitance of biomimetic lipid bilayers. Our approach utilizes the ellipsoidal deformation of quasi‐spherical giant unilamellar vesicles induced by a uniform AC electric field. Vesicle shape depends on the electric field frequency and amplitude. Membrane bending rigidit...
Article
Full-text available
Resealing of membrane pores is crucial for cell survival. Membrane surface charge and medium composition are studied as defining regulators of membrane stability. Pores are generated by electric field or detergents. Giant vesicles composed of zwitterionic and negatively charged lipids mixed at varying ratios are subjected to a strong electric pulse...
Article
Full-text available
Infection with Plasmodium falciparum enhances extracellular vesicle (EV) production in parasitized red blood cells (pRBCs), an important mechanism for parasite-to-parasite communication during the asexual intraerythrocytic life cycle. The e ndosomal s orting c omplex r equired for t ransport (ESCRT), and in particular the ESCRT-III sub-complex, par...
Article
Interferon-induced transmembrane protein 3 (IFITM3) potently inhibits entry of diverse enveloped viruses by trapping the viral fusion at a hemifusion stage, but the underlying mechanism remains unclear. Here, we show that recombinant IFITM3 reconstituted into lipid vesicles induces negative membrane curvature and that this effect maps to its small...
Preprint
Full-text available
Viscosity is a key mechanical property of cell membranes that controls time-dependent processes such as membrane deformation and diffusion of embedded inclusions. Despite its importance, membrane viscosity remains poorly characterized because existing methods rely on complex experimental designs and/or analyses. Here, we describe a facile method to...
Article
In general, biomembranes and giant vesicles can respond to cues in their aqueous environment by remodeling their molecular composition, shape, or topology. This themed collection focuses on remodeling of membrane shape which is intimately related to membrane curvature. In this introductory contribution, we clarify the different notions of curvature...
Article
Full-text available
Self-coacervation of animal-derived proteins has been extensively investigated while that of plant proteins remains largely unexplored. Here, we study the process of soy glycinin self-coacervation and transformation into hollow condensates. The protein hexameric structure composed of hydrophilic and hydrophobic polypeptides is crucial for coacervat...
Presentation
Full-text available
Work Contribution: Tripta Bhatia (Presenting author), Simon Christ (Soft Matter Paper), Jan Steinkühler (Nature Communications, Soft Matter papers), Ziliang Zhao (Nature Communications paper), Jaime Agudo-Canalejo (ACS-NANO Paper), Tom Robinson (Microfluidics Project Supervisor), Rumiana Dimova (Projects Supervisor), Reinhard Lipowsky (Projects Sup...
Poster
Full-text available
Work Contribution: Tripta Bhatia (Presenting author), Simon Christ (Soft Matter Paper), Jan Steinkühler (Nature Communications, Soft Matter papers), Ziliang Zhao (Nature Communications), Jaime Agudo-Canalejo (ACS-NANO Paper), Tom Robinson (Microfluidics Project Supervisor), Rumiana Dimova (Projects Supervisor), Reinhard Lipowsky (Projects Superviso...
Preprint
Infection with Plasmodium falciparum enhances extracellular vesicles (EVs) production in parasitized red blood cells (pRBC), an important mechanism for parasite-to-parasite communication during the asexual intraerythrocytic life cycle. The e ndosomal s orting c omplex r equired for t ransport (ESCRT), and in particular the ESCRT-III sub-complex, pa...
Article
Full-text available
The phase separation in aqueous solutions of a double-hydrophilic block copolymer (DHBC) at concentrations mimicking the crowded environment in cells and its performance as a potential protein purification system are investigated. Similar to processes of self-coacervation, the coexistence of aqueous polymer-rich and polymer-depleted microscopic pha...
Article
Full-text available
A novel osmotic pressure sensor based on liposomes loaded with FRET dyes is developed, which experience volume changes responding to osmotic pressure due to water outflux through their semipermeable membrane. With FRET microscopy, measurement of osmotic pressures in situ with spatiotemporal resolution is demonstrated, which has not been achieved so...
Article
Full-text available
Osmotic pressures play essential roles in biological processes and numerous technological applications. However, the measurement of osmotic pressures in‐situ with spatiotemporal resolution has not been achieved so far. Here, we introduce a novel kind of osmotic pressure sensors based on liposomes (average hydrodynamic diameter ≈ 1 μm) loaded with h...
Article
Full-text available
A widely used method to measure the bending rigidity of bilayer membranes is fluctuation spectroscopy, which analyses the thermally-driven membrane undulations of giant unilamellar vesicles recorded with either phase-contrast or confocal microscopy. Here, we analyze the fluctuations of the same vesicle using both techniques and obtain consistent va...
Preprint
Full-text available
Resealing of membrane pores is crucial for cell survival. We studied the membrane surface charge and medium composition as defining regulators triggering bursting and collapse of giant unilamellar vesicles upon poration. The pores were generated by either electric field or a detergent. Vesicles composed of mixtures of zwitterionic and negatively ch...
Article
Full-text available
We use a microfluidic method to estimate the water permeability coefficient (p) of membranes. As model lipid membranes we employ giant unilamellar vesicles (GUVs) composed of palmitoyloleoyl phosphatidylcholine and cholesterol (10 mol%). We have developed a microfluidic device with multiple chambers to trap GUVs and allow controlled osmotic exchang...
Preprint
Full-text available
Biological cells are contained by a fluid lipid bilayer (plasma membrane, PM) that allows for large deformations, often exceeding 50% of the initial (or projected) PM area. Biochemically isolated lipids self-organize into membranes, but the extraordinary deformability of the plasma membrane is lost. Pure lipid bilayers are prone to rupture at small...
Article
Full-text available
Front Cover : In article number 2000053 by Rumiana Dimova, Bernhard V. K. J. Schmidt, and co‐workers, the double hydrophilic block copolymer poly(N,N‐dimethylacrylamide)‐b‐pullulan shows a unique aggregation behavior in aqueous solution at concentrations above 20 wt% leading to a polymer rich and a polymer depleted phase. At this concentration cros...
Article
Full-text available
Cytochrome bo 3 ubiquinol oxidase is a transmembrane protein, which oxidizes ubiquinone and reduces oxygen, while pumping protons. Apart from its combination with F1Fo-ATPase to assemble a minimal ATP regeneration module, the utility of the proton pump can be extended to other applications in the context of synthetic cells such as transport, signal...