Could you introduce yourself?

I obtained my PhD degree in chemistry in 2003 from Kyiv National University and worked as post-doctoral fellow in the University of Strasbourg and Catholic University of Leuven. Then, I joined CNRS in 2006. I am CNRS Research Director at the Laboratory of Biophonics and Pathologies (University of Strasbourg, UMR CNRS 7021). My scientific background is chemistry, but I have been working for years at the interface of chemistry, biology and photonics.

Currently, I lead the research team “Photoactive Materials and Bioimaging”, and I am the co-founder of two startups: BrightSens Diagnostics and AstraNICE.

You have recently been awarded the CNRS Silver Medal. Could you tell us more about your research and its main focus?

Our research interests include two major research directions:

• The first direction is fluorescent molecular probes, which are functional organic molecules capable to image and sense biological systems. Here, we work on (a) probes for non-covalent and covalent targeting of specific cell compartments (plasma membranes, ER, Glogi, mitochondria, etc); (b) probes for advanced microscopy, aimed to improve its resolution (switchable probes for PAINT imaging) and the information content (ratiometric environment-sensitive probes) (c) probes for molecular recognition, which are able to detect and image specific biomolecular targets such as lipids, membrane receptors and RNA.
• The second research direction is photoactive nanoscale biomaterials for sensing, clinical diagnostics as well as photo-modulation and phototherapy. It includes new concepts of assembly of bright fluorescent nanoparticles (NPs) and nano-biosensors for point-of-care diagnostics (created start-up BrightSens Diagnostics). Recently, we starting working on artificial receptors for small molecules (neurotransmitters), which will enable their sensing, capture and photo-release in biological fluids, cells and tissues (supported by ERC Advanced grant CaptuRel since 2025). At the larger scale, we work on photoactive nano/micro-materials for image-guided surgery (created startup AstraNICE) and for sensing small molecules (O2, pH, reactive oxygen/nitrogen species, metabolites) and monitoring of wound healing.

Could you explain the fluorescent probes you develop for bioimaging? What makes them innovative?

Primary, we work on fluorescent biological membranes and organelles, where we image and sense their local biophysical properties. The innovation of our probes stems from the environment-sensitivity of our dyes. They are able to change their color or light up in response to local properties of biomembranes and biomolecules or to biomolecular interactions, such as ligand-receptor binding. Moreover, we proposed innovative strategies to target specifically the cell plasma membranes, which yielded families of membrane probes (e.g. MemBright and polarity probes), which were commercialized and used worldwide.

On the other hand, we develop fluorescent nanoparticles featuring high brightness for amplified sensing of biological markers of diseases, RNA in particular, and artificial nanoscale receptors for small molecules (neurotransmitters), important in diagnostics of neural disorders and neurobiology research.

Which microscopy systems are these probes designed to be used with?

They are suitable for a large variety of fluorescence microscopy techniques. First, they can be used for conventional cellular imaging using epi-fluorescence and confocal microscopy in wash-free conditions.

Environment-sensitive probes are designed for quantitative microscopy methods, such as ratiometric imaging and fluorescence lifetime imaging.

Finally, we make particular stress on probes for super-resolution imaging, with focus on PAINT imaging, by exploiting the capacity of our probes to light-up on the target binding.

What are the main biological applications of your fluorescent probes?

The primary applications are imaging of biological membranes of cell surface and organelles and monitoring changes in their biophysical properties in response to the external stress (oxidative, mechanical, etc) and physiological processes such as apoptosis. Other probes are particularly suitable for sensing ligand-receptor (GPCR) binding or intracellular RNA (using aptamers). Our nanoparticle probes are suitable for detection of biological markers (RNA and small molecules) of infectious, cancer and neurological diseases as well as for monitoring wound healing.

Are these probes accessible through microscopy facilities?

Yes, we are part of France Bioimaging (FBI) community, where we distribute the probes. We also distribute all new probes through direct contacts and many of our probes are already commercialized.

What are the next directions for your research?

In the field of molecular probes, we are particularly interested in (a) covalent probes for cell membranes based on our recently reported MemGraft probe family, (b) probes for sensing and imaging cell organelles, and (c) probes for super-resolution PAINT imaging. In the nanoscale probes, we recently started working on artificial receptors for small molecules. It will enable their direct detection in biological fluids, cells and in tissues, which is something very difficult to do with existing methods.

Moreover, we would like to combine sensing, capture and photo-release functions within these receptors, which will yield a new class of materials, like artificial neurons, able to “communicate” with living cells (supported by ERC Advanced Grant CaptuRel).

What message would you like to share with the bioimaging community and potential users of these probes?

Please, do not hesitate to try new tools developed by chemists. I think a lot of breakthroughs in answering biological questions and developing new bioimaging methods comes from the interaction of chemists and biologists who dare to speak to each other.