Copper ions are essential for life but posses a redox-activity which makes them potentially toxic, and their cellular availability is highly regulated by an intricate network of intracellular chaperones, transcription factors and membrane transporters. Copper homeostatic imbalance is connected to several major neurological diseases. The detailed mechanisms of copper movement across membranes remain unknown due to the difficulty to characterize at atomic level the different proteins involved, which are mainly integral membrane systems. In humans, high-affinity copper uptake is modulated by hCTR1, a trimeric membrane transporter which has so far fled from high-resolution x-ray or cryo-EM investigations and is extremely challenging to produce and recover in workable amounts for structural studies. The central objective of the present project is to develop and apply a solid-state Magic-Angle Spinning (MAS) NMR approach to allow complete characterization of the structure and mechanism of lipid-bound hCTR1. Building on a decade of continuous advances of the NMR community, the recent development of very fast (up to 100 kHz) MAS probes has revolutionised this field, with developments that speed up the analysis of proteins of considerable size and open the way to complex biological solids available in limited amounts. We propose to leverage the unique expertise and equipment available in the consortium, and achieve the objectives above through a combination of innovative strategies for isotopic sample preparation, advanced spectroscopic tools to obtain NMR signatures of the structure and dynamics, and new instrumentation capable of even faster MAS rates. The project will provide breakthrough data for understanding structure-activity relationships in a challenging integral membrane protein, and will allow the addition of solid-state NMR to the method portfolio for the characterization of medically relevant targets.

Singlet oxygen, an excited state of molecular oxygen is a highly reactive species, relevant for an array of applications, ranging from sustainable oxidation catalysis to photodynamic therapy (PDT). The development of tailored materials capable of precisely controlling the generation and manipulation of singlet oxygen is paramount for advancing these applications. PDT, in particular, serves as a compelling example highlighting the importance of controlled singlet oxygen management. It relies on the interplay between a photosensitizer (PS), light, and ground state oxygen (3O2), producing highly reactive oxygen species such as the cytotoxic singlet oxygen (1O2) that is used to destroy cancer and microbial pathogens. Currently PDT faces two key limitations: the control of oxygen supply and limited light penetration inside the tissues. MOFSONG project addresses these limitations by proposing innovative materials capable of decoupling the light irradiation and the 1O2 release steps. The proposed approach involves the design and synthesis of porous Metal Organic Frameworks (MOFs) combining two types of organic linkers: arenes and porphyrins in a single porous structure. Porphyrins are excellent PSs capable of generating 1O2, and arenes are aromatic molecules capable of trapping this 1O2 in their structure upon a cycloaddition reaction and endoperoxide (EPO) formation, while porosity favors the concentration and fast diffusion of oxygen species. Thus, MOFs containing EPO can be generated by illumination at the optimum porphyrin excitation wavelength and stored at low temperature until being used to controllably release 1O2 in a desired environment upon heating. The project objectives involve the synthesis of molecular building units, the development of porous materials assisted by the design of experiments and robotic synthesis, comprehensive structural and spectroscopic investigations and the study of 1O2 dynamics. The success of the project is assured through an interdisciplinary consortium of five research partners providing all the necessary expertise and state of the art facilities.

In this project I will develop new spectroscopy approaches that will allow one to obtain unprecedented structural information of drug molecules throughout the whole pharmaceutical process. High resolution structure determination ideally of unmodified drugs (i) in their free form, but also (ii) in complex dosage formulations, as well as (iii) during their delivery and target engagement in cells represents one of today’s major challenges in pharmaceutical industry, key to ensure productive drug uptake and improved efficacy. Current routine characterisation methods (such as detection of drugs in cells) often require sample modification (e.g. tagging with fluorescent labels) which may alter the behaviour of the drug. Here I will make use of the fact that a increasingly growing percentage (currently about 30%) of Active Pharmaceutical Ingredients (API) contain at least one fluorine atom, while hardly any excipients and no endogenous biomolecules in human cells do. By implementing innovative 19F solid state Nuclear Magnetic Resonance (NMR) approaches under fast Magic-Angle Spinning (MAS) and Dynamic Nuclear Polarisation (DNP) techniques, I will develop a new analytical tool with enhanced resolution and sensitivity, which will allow one to overcome the above mentioned challenges and to obtain structural information of unmodified drug molecules in complex and diverse formulation, in vitro and in cellular environments, as well as their interactions with various substrates (excipients, biological targets). The 19F NMR observables will be correlated with those of other nuclei (1H, 13C and 15N at natural abundance), using multidimensional 19F detected methods to distinguish between the drug molecule and excipients or cell background. The methods will be benchmarked on a variety of pharmaceutically relevant molecules and will concern both their pure constituents and their delivery systems.

The coordination-driven self-assembly strategy is remarkably efficient in building discrete polygons and cages, unreachable through usual covalent chemistry. This approach, directed through thermodynamic control, is supported by both the highly predictable directionality of the metal-ligand coordination sphere and the reversible nature of the coordination bonds. In addition to discrete structures, topologically more complex assemblies have appeared in the recent literature, and correspond to interlocked cages (based on interpenetrated systems). A step further was also realized through the formation of their respective oligomeric/polymeric analogues, i.e. polycatenated cages. At this stage, it appears that there is an urgent need to address the scope of this new fascinating family of compounds, both in terms of rational design guiding their synthesis and by exploring their unique characteristics towards new applied scientific frontiers. The proposed PoDACC project aspires to address these issues, through designing a select family of hybrid cages, featuring both electron-donor (D) and -acceptor (A) units. Detailed investigations of such original self-assembled structures will: 1) address the basics for the formation of interlocked coordination cages, and will extend the concept to polycatenated cages; 2) enable an original redox-assisted synthesis of interlocked architectures, through enhanced intermolecular interactions, a key factor to overcome the entropy cost related to the construction of such objects; 3) control the relative organization and stoichiometry of D and A partners in the supramolecular system, leveraging the unique topology of the target interlocked architectures. The synthetic parameters and the resulting structures and photophysical properties of the supramolecular assemblies will be assessed through coupled theoretical and experimental approaches, the latter involving solid-state NMR, spectroelectrochemical measurements, electrocrystallization, FT-ICR mass spectrometry and DFT. Finally, such innovative self-assembled materials will provide unique opportunities to assess this new family of structurally controlled architectures for molecular electronics applications.

Conventional high field liquid state nuclear magnetic resonance (NMR) is a powerful method but experiments need to be performed in a specific environment (inside a highly homogeneous magnetic field), which prevents its use in many applications. Coupling magnetic resonance at zero- to ultralow field (ZULF) [1] with hyperpolarization [2] by dissolution-dynamic nuclear polarization (dDNP) [3–5] allows for sensitive high resolution magnetic resonance with arbitrary molecules in challenging environments like metal containers and porous media with high magnetic susceptibility heterogeneities. This requires a robust experimental setup combining the two techniques. Boosting NMR at zero field with dDNP is challenging because of relaxation induced by paramagnetic agents. We believe that this limitation will be lifted by the use of hyperpolarizing matrices recently introduced by the French co-applicant. We will use the combination of hyperpolarization and ZULF NMR to investigate catalytic hydrogenation of unsaturated compounds, heterogeneous enzymatic processes and oligomerization and polymerization processes. In particular, this will enable the comparison of homogeneous vs. heterogeneous catalytic processes by NMR.