The activity of the team was originally focused on the interaction of light with different classes of chromophores of biological and / or biomedical interest. Some of these chromophores exhibit a high triplet state quantum yields that enable reactive oxygen species (ROS) production. Such agents are defined as photosensitizer. We have already shown that it became possible to use these molecules to disturb the membrane models in a fine and controlled way. Our main goal today is to achieve greater levels of membrane complexity, to further explore the involved mechanisms, but also to strengthen their relevance to the biological point of view. Our aim is not only to change the composition of the model membranes on which we work, but mainly to better understand the relationship between membrane composition, its morphology and one specific biological activity. In this view, biomimetic membrane models such as proteo-liposome is used.

We are particularly interested in mitochondrial membranes. In eukaryote cells, mitochondria are key organelles for energy production and apoptosis that constantly fuse and divide. Two membranes constitute their envelope, with different levels of permeability. A hallmark of the inner mitochondrial membranes (IMM) is the presence of dynamic invaginations called “cristae”. These nanostructures (20-50 nm), rich in a specific mitochondrial phospholipid, the cardiolipin (CL), can change their shape and their density depending on energy demand. Their relative integrity is usually considered as a relevant indicator of the functional state of mitochondria, since cristae contain the OXPHOS complexes responsible for ATP production and they sequester Cytochrome C which release is involved in apoptotic signaling. Specific alterations of cristae morphology induce mitochondrion dysfunctions (in the Barth syndrome for example), and in many pathological situations, such alterations are also observed. Thus, our goal is to understand the role, the dynamic and the impact of cristae on mitochondrial function.