Fistulas are a major neglected health burden related to Crohn's disease or secondary to surgery, cancer therapy or trauma. Post-surgical digestive fistulas are challenging conditions associated with low remission rates and high refractoriness. There is an urgent need of novel therapeutic approaches for this disease. FisTher investigates an alternative to cell therapy approach, by proposing a minimally-invasive cell-free local therapy based on the regenerative effect of extracellular vesicles (EVs) from mesenchymal stem/stromal cells (MSCs). We consider that MSC EVs represent an eligible alternative for fistula therapy, as they recapitulate the regenerative effect of their mother cells while mitigating risks of uncontrolled replication, differentiation and vascular occlusion, offering “off-the-shelf”, storage and shelf-life gains. The main challenges for rendering EV-based regenerative medicine clinically feasible are large-scale high-yield standardized EV production and EV optimized administration. Concerning EV manufacturing, stringent requirements must be considered such as up-scaled and high-yield production fulfilling uniformity, consistency, purity and reproducibility criteria based on standardized and reliable quality control. The way EVs are administered also represents a main concern considering that systemic administration results in rapid EV clearance and localization in off-target organs. Building on the PI previous work, our strong preliminary results, our intellectual property and complimentary collaborators, FisTher has the ambition to render viable the implementation of EV-based therapy by tackling EV production and administration technical barriers. FisTher proposes large-scale high-yield EV production based on our patented concept of turbulence-vesiculation complying with a standardized production in GMP bioreactors in line with regulatory issues. FisTher set-up relies on the generation of a controlled turbulent flow in which turbulence microvortices will elicit a shear stress on cells triggering EV release. This turbulence-based strategy is (i) time-saving enabling massive EV release in some hours, (ii) integrated as it is based on tuning the own GMP bioreactor stirring system, (iii) straightforward as no further processing is required to eliminate the trigger (turbulence disappearing when stirring is turned off) and (iv) scalable based on turbulence flow parameters. FisTher also proposes a thermo-actuated EV delivery in the fistula tract for eliciting an enhanced therapeutic effect in situ. FisTher strategy is expected to avoid systemic administration clearance and overcome difficulties related to local delivery, such as fistula secretions (washing-out the therapeutic agent) and fistula tract inaccessibility (sometimes irregular large defects of several centimeters). FisTher relies on dual biomaterial/EV component for fistula therapy. The thermoresponsive hydrogel biomaterial component is expected to cope with fistula local delivery difficulties promoting an occlusive effect, retaining EVs in the fistula tract and preventing EV wash-out by fistula secretions, while enabling the filling of the entire fistula tract despite its size and irregular morphology. Biomaterial choice was based on material physical and therapeutic properties and considered a clinical translation perspective. Building on strong preliminary results, we intend to investigate the combination of turbulence EVs with a poloxamer 407 hydrogel. FisTher proposes the off-label use of this hydrogel, which is a vessel occlusive medical device authorized in Europe, as an innovative fistula occlusive EV vehicle. FisTher fully considers key regulatory and manufacturing issues in the project choices to set the basis for implementing the first future clinical trial on MSC EVs for the therapy of post-surgical digestive fistulas.

The global shift towards a greener economic model requires replacing non-renewable chemicals with sustainable ones, whose performance at least matches that of their predecessors while they meet the most up-to-date norms. Rapid standard adaptability is critical in many fields such as cosmetics, oil recovery, construction, food and the automotive industry. In this ever-changing context, methods that speed up chemical synthesis, characterization and optimization are highly desirable. The goal of the CARANGONI proposal is to address this challenge. We propose to investigate how Marangoni flows could be used as the basis for a fast and cheap characterization tool for the solubility of chemical species. Some of us have shown in the past that the size of Marangoni flows induced by the injection of simple water-solube and surface-active species at the surface of a water layer was set by both the flow rate at which molecules were injected and their solubility limit in water before aggregation, also known as the critical micelle concentration. The relation between these three quantities was a simple scaling law. Thus, using a pocket calculator, we can deduce a thermodynamic property of surface-active molecules in solutions from the measurement of the size of a flow with a ruler. Besides, a single measurement is required. This feature must be contrasted with the need of large amounts of material and time necessary to perform measurements of the cmc with classical mehtods (pendent drop, conductometry,...). So far, we have tested simple molecules that are far from the molecular systems used in the industry. In the CARANGONI proposal, we want to generalize Marangoni characterization to complex and closer-to-application molecular systems, such as surfactant-polymer mixtures or surfactants in the presence of salts. We also want to explore extensions of the Marangoni set-up to the removal of impurities in surfactants and to DNA-based nanoparticle synthesis. Finally, we want to benefit from the beauty of the experiment to develop outreach tools around interface science. Our consortium involves four groups from three labs, Matière et Systèmes Complexes, Laboratoire de Physique des Solides and Institut de Physique de Rennes, in Paris and Rennes. The consortium gathers expertise in both experimental and theoretical approaches to interface sciences, hydrodynamics, and self-assembly. Popularization has a significant place in this project, and the proposal includes a specific task dedicated to dissemination. The consortium involves researchers in this field who have developed innovative strategies to popularize other topics of physics such as quantum mechanics. The proposal benefits from the support of the french company TECLIS, based in Lyon, who is a leading manufacturer of interface characterization devices. The members of the consortium have already started developing a prototype device based on the automation of the measurement of Maragoni flows for the fast characterization of the solubility of chemical species. The aim of this device is at the formulation level and in quality control.

Turbulence occurs in most astrophysical and geophysical flows, as well as in many industrial processes. In most situations, turbulence transfers energy from large to small scales. For three-dimensional flows, energy is injected at the forcing scale and nonlinear interactions transfer it to shorter spatial scales where it is efficiently dissipated by viscosity. The small scales of turbulent flows are supposed to be universal and have been studied in great details in various contexts. In contrast less is known for the large scales. The aim of this project is to study the properties of the large scales in turbulence, here defined as the scales larger than the forcing scale. We propose to study experimentally and numerically two canonical systems to determine the behavior of large scale turbulent fluctuations under different circumstances. The first system is three dimensional homogeneous isotropic turbulence (3DT) and the second system is gravity wave turbulence (GWT) on the surface of a fluid. We will develop two large scale experiments in which we will create a flow or an ensemble of waves at small scale compared to the largest scale of the system. The technical barrier is to create intense enough turbulence in a controlled manner to be able to generate larger scales. Our program contains back-up solutions to make sure that these experiments will be successful. These two systems have different large scale properties. In 3D homogeneous turbulence no cascade to the large scales is expected while an inverse cascade of wave action towards the large scales is predicted for surface gravity wave turbulence. The purpose of our project is thus to perform a detailed study of the large scales with the largest possible scale separation in order to better understand the two possible situations: with inverse cascade (GWT) or without inverse cascade (3DT). We want to understand and quantify the relation between the large scales and the fluxes of energy or wave action. Beyond the mean properties we will also focus on dynamical ones. To wit, we plan to perform accurate measurements of the instantaneous injected power and to develop and implement a new optical method to measure the instantaneous dissipation rate using Diffusing Wave Spectroscopy. In the case of 3D turbulence, as there is no mean energy flux towards the larger scales, it is expected that these scales are in statistical equilibrium, i.e. all the modes have the same energy. An expected result is to observe and characterize this regime experimentally. This would provide a new way to model the large scales using the tools of equilibrium statistical mechanics. In particular, our project will give a path to define for a turbulent system the effective temperature of a large scale flow or to predict the properties of rare events or the ones of the fluctuations of injected power. Such concepts are likely to be valid in the 3D turbulent system and we will investigate to what extent they also apply in the system of waves for which an inverse cascade exists. We shall test these concepts in the experiments and compare them with numerical simulations. Despite being limited in the accessible parameter range, the simulations will be useful as they provide access to quantities difficult to measure in the experiments.

Regenerative therapy based on the use of mesenchymal stem cells (MSC) is a promising approach for the treatment of stroke. The beneficial effects of MSC appears to be mainly related to the secretion of cellular factors and/or extracellular vesicles (EV). Heparan sulfates present on the surface of producing and recipient cells as well as on EV could play a critical role in the EV-mediated communication. The MAESTROVE project will explore, through the use of innovative approaches and models developed by 4 partners, the ability of combining human MSC-derived EV with a HS mimetic (HSm) agent, i.e. OTR4132, to enhance EV-mediated tissue regeneration and functional recovery following stroke, thus opening a new and rapid perspective for a development more easily industrialized for the treatment of stroke. The research hypothesis of the project lies on the fact that OTR4132 will create/restore a favourable tissue environment in which MSC-derived EV will be satisfactorily trapped and thus exert their beneficial effects in an optimal manner in the damaged brain tissue after stroke. Moreover, in vitro MSC priming with OTR4132 could improve EV biogenesis, cargo composition and regenerative properties. Combining HSm-based matrix therapy and MSC-derived EV therapy has never been studied. Another originality of this project is to test a priming strategy of MSC with this HSm-based matrix therapy to improve EV cargo constitution. This project will also evaluate for the first time a high-yield and scalable turbulence EV production approach for post-ischemic stroke treatment. This therapeutic strategy will be tested in relevant animal models of stroke towards the clinic, including the integration of the main comorbidity factor, i.e. the pre-existence of chronic arterial hypertension and an original non-human primate model. Overall, this project aims to provide an improved EV-based therapy that could represent a new clinically cell-free feasible paradigm for stroke. MAESTROVE gathers 4 partners with complementary expertise, most of them collaborating for a long time together with publications, patents and joint funding including 3 academic laboratories (Partner 1: ISTCT unit, Partner 3: Gly-CRRET unit and Partner 4: MSC unit) and 1 SME (Partner 2: OTR3). This project is subdivided into 5 Work Packages with WP1 for project management; WP2 for EV production by turbulence and characterization; WP3 for in vitro potency studies of EV (derived from MSC primed or not with OTR4132) in association or not with OTR4132 on neuronal, glial and endothelial cells survival submitted to an ischemic-like stress; WP4 for effects of combined therapies (OTR4132/EV) in different stroke models in the rat and marmoset; WP5 for effects of combined therapies (OTR4132/EV) on endogenous GAG modifications induced by stroke and blood markers identification of treatment efficacy. The MAESTROVE project proposes to develop a new therapy concept with the combination of OTR4132 and EV produced by human MSC. The success of the project is strongly supported by the proven effectiveness of OTR4132 and combined OTR4132/MSC in stroke tissues. Partner 2 has exclusive and worldwide rights for the engineering of matrix agents (RGTA®, ReGeneraTing Agents including OTR4132) and its applications in nervous system pathologies. Besides, the development of GMP EV production by turbulence from human MSC is on ingoing for a future clinical via a bioproduction start-up (EverZom) exploiting the patent from Partner 4.

Large assemblies of living or synthetic self-propelled particles make up Active Matter. They operate far from equilibrium without necessarily leading to macroscopic currents, hence a superficial resemblance to their equilibrium counterparts. Our project focuses on the theoretical challenges posed by the emergent local and global order observed in such systems. It builds on the counterintuitive idea, supported by encouraging attempts, that thermodynamics-based ideas will help rationalize and predict the wealth of phase behaviors observed in active systems. Our threefold approach is based on exploring statistical concepts like entropy (without its thermal meaning, understood as a means of counting states), exploring mechanical or chemical concepts like pressure, chemical potential, surface tension (without their free energy interpretation), and connecting local structure to effective interactions, by means of energetics or dynamic approaches (without invoking the Boltzmann measure).