Publications de Orly Bagunu Tarun

Membrane Potential Fluctuations and Water Asymmetry on Plasma Cell and Model Lipid Membranes: Origins, Implications and Properties

Arianna Marchioro, Bryan Zhi Li, Sylvie Roke, Orly Bagunu Tarun, Iwona Swiderska, Maksim Eremchev, David Roesel, Seonwoo Lee, Mischa Samuel Flór

Membrane potential fluctuations have previously been detected using second harmonic (SH) water imaging on neuronal cells and model lipid bilayer membranes. We report that such fluctuations are also visible when membrane potential-sensitive fluorophores are ...

ROYAL SOC CHEMISTRY2025

Solvent Redistribution Method To Determine Solubility and Aggregation: High Throughput, Accuracy, and Sustainability

Sylvie Roke, Nathan Dupertuis, Orly Bagunu Tarun

American Chemical Society (ACS)2025

Three-Dimensional Confinement of Water: H2O Exhibits Long-Range (> 50 nm) Structure while D2O Does Not

Sylvie Roke, Nathan Dupertuis, Cornelis Ulrich Lütgebaucks, Orly Bagunu Tarun

Water is the liquid of life thanks to its three-dimensional adaptive hydrogen (H)-bond network. Confinement of this network may lead to dramatic structural changes influencing chemical and physical transformations. Although confinement effects occur on a < ...

AMER CHEMICAL SOC2022

Transient domains of ordered water induced by divalent ions lead to lipid membrane curvature fluctuations

Sylvie Roke, Orly Bagunu Tarun, Halil Ibrahim Okur

Cations influence the electrostatic, chemical and mechanical properties of lipid bilayers. Here, label-free second harmonic microscopy shows that cation-induced transient ordering of water also plays a role in driving membrane curvature fluctuations, linki ...

NATURE PUBLISHING GROUP2020

Spatiotemporal Imaging of Water in Operating Voltage-Gated Ion Channels Reveals the Slow Motion of Interfacial Ions

Aleksandra Radenovic, Sylvie Roke, Orly Bagunu Tarun, Maksim Eremchev

Ion channels are responsible for numerous physiological functions ranging from transport to chemical and electrical signaling. Although static ion channel structure has been studied following a structural biology approach, spatiotemporal investigation of t ...

American Chemical Society (ACS)2019

Chemistry of Lipid Membranes from Models to Living Systems: A Perspective of Hydration, Surface Potential, Curvature, Confinement and Heterogeneity

Sylvie Roke, Orly Bagunu Tarun, Halil Ibrahim Okur

Lipid membranes provide diverse and essential functions in our cells relating to transport, energy harvesting and signaling. This variety of functions is controlled by the molecular architecture, such as the presence of hydrating water, specific chemical c ...

2019

Dynamic Imaging of Lipid Membranes by Means of Water

Orly Bagunu Tarun

Lipid membranes are self-assembled structures whose composition determines the properties of membranes of cells and organelles. The molecular level understanding of lipid membranes is based on spectroscopy and MD simulations of lipid monolayer systems. As ...

EPFL2019

Label-free and charge-sensitive dynamic imaging of lipid membrane hydration on millisecond time scales

Sylvie Roke, Orly Bagunu Tarun

Biological membranes are highly dynamic and complex lipid bilayers, responsible for the fate of living cells. To achieve this function, the hydrating environment is crucial. However, membrane imaging typically neglects water, focusing on the insertion of p ...

2018

Membrane water for probing neuronal membrane potentials and ionic fluxes at the single cell level

Pierre Magistretti, Pascal Jourdain, Sylvie Roke, Marie Eve Pascale Didier, Orly Bagunu Tarun

Neurons communicate through electrochemical signaling within a complex network. These signals are composed of changes in membrane potentials and are traditionally measured with the aid of (toxic) fluorescent labels or invasive electrical probes. Here, we d ...

Nature Publishing Group2018

Interaction of Oil and Lipids in Freestanding Lipid Bilayer Membranes Studied with Label-Free High-Throughput Wide-Field Second-Harmonic Microscopy

Sylvie Roke, Orly Bagunu Tarun, Maksim Eremchev

The interaction of oils and lipids is relevant for membrane biochemistry since the cell uses bilayer membranes, lipid droplets, and oily substances in its metabolic cycle. In addition, a variety of model lipid membrane systems, such as freestanding horizon ...

2018

Label-free dynamic imaging of free standing lipid membranes and their hydration

Sylvie Roke, Orly Bagunu Tarun

AMER CHEMICAL SOC2018

Low photodamage label-free imaging of single cell activity aimed at mapping neuronal activity

Sylvie Roke, Marie Eve Pascale Didier, Orly Bagunu Tarun

AMER CHEMICAL SOC2018

High throughput second harmonic imaging for label-free biological applications

Pierre Marquet, Pierre Magistretti, Pascal Jourdain, Aleksandra Radenovic, Sylvie Roke, Carlos Alberto Macias Romero, Marie Eve Pascale Didier, Vitalijs Zubkovs, Orly Bagunu Tarun

Second harmonic generation (SHG) is inherently sensitive to the absence of spatial centrosymmetry, which can render it intrinsically sensitive to interfacial processes, chemical changes and electrochemical responses. Here, we seek to improve the imaging th ...

Optical Society of America2014