ERC FUNDED PROJECTS

This project will focus on the use of nanoporous metal organic frameworks (Fe, Zn, Ti) for bioapplications. These systems are exciting porous solids, built up from inorganic clusters and polycarboxylates. This results in open-framework solids with different pore shapes and dimensions, and applications such as catalysis, separation and storage of gases. I have recently initiated the synthesis of new trivalent transition metal carboxylates. Among them, the metal carboxylates MIL-100 and MIL-101 (MIL: Materials of Institut Lavoisier) are spectacular solids with giant pores (25-34 Å), accessible metal sites and huge surface areas (3100-5900 m2.g-1). Recently, it was shown that these solids could be used for drug delivery with a loading of 1.4 g of Ibuprofen per gram of MIL-101 solid and a total release in six days. This project will concentrate on the implication of MOFs for drug release and other bioapplications. Whereas research on drug delivery is currently focused either on the use of bio-compatible polymers or mesoporous materials, our method will combine advantages of both routes including a high loading and a slow release of therapeutic molecules. A second application will use solids with accessible metal sites to coordinate NO for its controlled delivery. This would provide exogenous NO for prophylactic and therapeutic processes, anti-thrombogenic medical devices, improved dressings for wounds and ulcers, and the treatment of fungal and bacterial infections. Finally, other applications will be envisaged such as the purification of physiological fluids. The project, which will consist of a systematic study of the relation between these properties and both the composition and structure of the hybrid solids, will be assisted by a strong modelling effort including top of the art computational methods (QSAR and QSPKR). This highly impact project will be realised by assembling experienced researchers in multidisplinary areas including materials science, biology and modelling. It will involve P. Horcajada (Institut Lavoisier), whose background in pharmaceutical science will fit with my experience in inorganic chemistry and G. Maurin (Institut Gerhardt, Montpellier) expert in computational chemistry.

1 250 000 €

Start date: 2008-06-01, End date: 2013-05-31

The goal of COMMOTION is to establish a strategy whereby functional molecular devices (e.g. photo-/electroactive) can communicate with one another in solution and in organized, self-assembled media (biotic and abiotic). Despite intense research, no single strategy has been shown to satisfactorily connect artificial molecular components in networks. This is perhaps the greatest hurdle to overcome if implementation of artificial molecular devices and sophisticated molecule-based arrays are to become a reality. In this project, communication between distant sites / molecules will be based on the use of photoejected ions in solution and organized media (membranes, thin films, nanostructured hosts, micellar nanodomains). Ultimately this will lead to coded information transfer through ion movement, signalled by fluorescent reporter groups and induced by photomodulated receptor groups in small photoactive molecules. Integrated photonic and ionic processes operate efficiently in the biological world for the transfer of information and multiplexing distinct functional systems. Application in small artificial systems, combining “light-in, ion-out” (photoejection of an ion) and “ion-in, light-out” processes (ion-induced fluorescence), has great potential in a bottom-up approach to nanoscopic components and sensors and understanding and implementing logic operations in biological systems. Fast processes of photoejection and migration of ions will be studied in real-time (using time-resolved photophysical techniques) with high spatial resolution (using fluorescence confocal microscopy techniques) allowing evaluation of the versatility of this strategy in the treatment and transfer of information and incorporation into devices. Additionally, an understanding of the fundamental events implicated during the process of photoejection / decomplexion of coordinated ions and ion-exchange processes at membrane surfaces will be obtained.

1 250 000 €

Start date: 2008-09-01, End date: 2013-08-31

The aim of COSIRIS is to isolate the simultaneous fluxes of photosynthesis and respiration of the terrestrial biosphere. With explicit knowledge of the component fluxes, we will: 1) test process based models of photosynthesis and respiration, 2) determine the sensitivity of each flux to environmental conditions, and 3) derive predictions of their responses to climate change. Specifically, COSIRIS aims to build a research facility to integrate a new tracer, carbonyl sulfide (COS) with CO2, water and their stable isotopes in a multi-tracer framework as a tool to separately investigate photosynthesis and respiration. In terrestrial ecosystems, CO2 is often taken up and released at the same time. Similar to CO2, COS is taken up during photosynthesis, but unlike CO2, concurrent COS emissions are small. Parallel COS and CO2 measurements thus promise to provide estimates of gross photosynthetic fluxes – impossible to measure directly at scales larger than a few leaves. The use of COS to derive CO2 fluxes has not been verified yet, but enough is known about their parallel pathways to suggest that COS, CO2 and its isotopes can be combined to yield powerful and unique constraints on gross carbon fluxes. COSIRIS will develop the expertise necessary to achieve this goal by providing: 1. an in-depth analysis of processes involved in COS uptake by vegetation, and of potentially interfering influences such as uptake by soil, 2. a novel process-based multi-tracer modelling framework of COS, CO2, water and their isotopes at the ecosystem scale, 3. extensive datasets on concurrent fluctuations of COS, CO2, water and their isotopes in ecosystems. This innovative approach promises advances in understanding and determining gross carbon fluxes at ecosystem to continental scales, particularly their variations in response to climate anomalies.

1 822 000 €

Start date: 2008-07-01, End date: 2014-10-31

Core formation represents the major chemical differentiation event on the terrestrial planets, involving the separation of a metallic liquid from the silicate matrix that subsequently evolves into the current silicate crust and mantle. The generation of the Earth’s magnetic field is ultimately tied to the segregation and crystallization of the core, and is an important factor in establishing planetary habitability. The processes that control core segregation and the depths and temperatures at which this process took place are poorly understood, however. We propose to study those processes. Specifically, the density of the core is lower than would be expected for pure iron, indicating that a light component (O, Si, S, C, H) must be present. Similarly, the Earth’s mantle is richer in iron-loving (“siderophile”) elements, e.g, V, W, Mo, Ru, Pd, etc., than would be expected based upon low pressure metal-silicate partitioning data. Solutions to these problems are hampered by the pressure range of existing experimental data, < 25 GPa, equivalent to ~700 km in the Earth. We propose to extend the accessible range of pressures and temperatures by developing protocols that link the laser-heated diamond anvil cell with analytical techniques such as (i) the NanoSIMS, (ii) the focused ion beam device (FIB), (iii) and transmission and secondary electron microscopy, allowing us to obtain quantitative data on element partitioning and chemical composition at extreme conditions relevant to the Earth’s lower mantle. The technical motivation follows from the fact that the real limitation on trace element partitioning studies at ultra high-pressure has been the grain size of the phases produced at high P-T, relative to the spatial resolution of the analytical methods available to probe the experiments; we can bridge the gap by combining state-of-the-art laser heating experiments with new nano-scale analytical techniques.

1 509 200 €

Start date: 2008-11-01, End date: 2013-10-31