Diffusion in confined environment

1.   Particle-based theranostic agents (TA) are small spheres filled with either gas or liquid. Injected into the blood, they significantly improve the quality of ultrasound or MRI images. Under precise experimental conditions, the TA can also carry molecules that fight various diseases. The number of molecules transported is then much lower than that of conventional drugs ingested. This effect reduces their toxicity for the patients. Some TA acts as “anti-disease missiles ” delivering active drugs to the exact point where the disease can be most effectively fought. We are building such TA and studying their interactions with ultrasounds experimentally (in vitro and in vivo) as well as in “silico” by modeling the interaction of ultrasonic waves with our TA. (With   Nicolas Taulier)

2.Efflux pumps:

Some bacteria possess a remarkable system of “pumps” for expelling through their membranes undesirable molecules such as antibiotics, heavy metals, etc..  We are exploring how these pumps self-assemble and operate. The problem is approached by molecular genetic and physical techniques including FRPP, microcalorimetry, X-ray and neutron scattering techniques…

3.Protein flexibility, assembly, and hydration. (With P. Fuchs and Nicolas Taulier)

New drugs for the therapy of diseases are identified with the help of high-throughput screening procedures that often ignore the role played, on molecular level, by bind water.

This approach impede the development of new drugs and make the binding assays the limiting factor and the most costly step in the screening of drug candidate molecules. Yet is known that water molecules play an important role in mediating protein-ligand interactions: when a ligand binds to a protein, water molecules are expelled from the hydration shell of the binding site and transferred to bulk water.

Once the structure of the binding pocked is known our goal is to correctly take into account hydration changes during the in this early stages of (in silico) binding.

We use ultrasonic spectroscopy that is very sensitive to any change in hydration but give only a macroscopic insight of the drug-binding event

In silico:

Details of the binding events will be provided by molecular dynamics of the system under study.

People related :