The ERC Starting Grant project ExocyTher focuses on a cell-free therapy for digestive fistulas related to Crohn's disease. The aim is to investigate extracellular vesicles (EVs) released by stromal cells. The project proposes the concepts of (i) turbulence vesiculation for high-yield and large-scale EV production in bioreactors and (ii) thermo-controlled local EV delivery at the fistula.
Digestive fistulas are a major health burden related to Crohn's disease or secondary to surgery, cancer therapy or trauma. Digestive fistulas are an abnormal communication between two digestive organs or a digestive organ and the skin representing challenging conditions associated with low remission rates and high refractoriness. There is an urgent need of novel therapeutic approaches for this disease. Such unmet needs in digestive fistula management motivated the investigation of cell therapy based on the local administration of stromal cells (SCs). These cells display multiple therapeutic effects and one of the main ones is to reduce the inflammation favoring the fistula healing process. Although cell therapy results are encouraging, they are not fully satisfactory in terms of percentage of patients that achieve log-term disease remission, leaving place for a second generation therapy. SCs are known to release pro-survival and anti-inflammatory signals by means of extracellular vesicles (EVs) pointing out EV role in regenerative medicine. The ExocyTher project investigates an alternative to cell therapy approach, by proposing a minimally-invasive cell-free local therapy based on the regenerative effect of EVs from SCs. Formerly regarded as a “cell dust”, EVs, specially from SCs, are now considered as regenerative agents able to play an important role in the healing process. Previous studies showed the beneficial effect of SC EVs in the therapy of heart, kidney, liver, brain and skin injuries (Figure 1). We consider that SC EVs represent an eligible alternative for fistula therapy, as they recapitulate the regenerative effect of their mother cells while mitigating risks of uncontrolled replication and differentiation while offering “off-the-shelf”, storage and shelf-life gains. Our previous results in a clinically relevant fistula disease model clearly indicated that a therapy based on SC EVs was able to promote post-surgical digestive fistula healing.
Today, 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 and compliance to good manufacturing practices (GMP). 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.
The ExocyTher project has the ambition to render viable the implementation of EV-based therapy by tackling EV production and administration technical barriers.
ExocyTher 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. ExocyTher 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 (Figure 2). Our approach is bio-inspired based on EV release by the turbulent flow in bloodstream. 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 physical laws.
ExocyTher also proposes a thermo-actuated EV delivery in the fistula tract (Figure 3) for eliciting an enhanced therapeutic effect in situ. ExocyTher 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). ExocyTher 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. ExocyTher proposes the off-label use of this hydrogel, which was a vessel occlusive medical device authorized in Europe, as an innovative fistula occlusive EV vehicle. This mechanical occlusive effect has an interest by itself in the therapy of digestive fistulas. Healing process is favored by decreasing the flow of secretions from the digestive system to the skin. Therefore, ExocyTher relies on a potential synergic effect of SC EVs and the thermoresponsive gel association.
ExocyTher fully considers key regulatory and manufacturing issues in the project choices to set the basis for implementing the first future clinical trial on SC EVs in a biomaterial for the therapy of digestive fistulas. Noteworthy, ExocyTher approaches may be extended to a multitude of EV parent cell types, or therapy indication. Therefore, the advances to be achieved in this project may also be relevant for unmet needs related to other diseases. We hope that the ExocyTher project may contribute in the future to democratize EVs as biotherapies for the management of digestive fistulas and other diseases with high morbidity or mortality. In a long-term perspective, by facilitating patient access to last generation therapies, ExocyTher technologies may improve the quality of life of refractory patients, tackling medical and societal challenges.
Amanda K. A. Silva (Brun) obtained a Pharmacy degree in 2005, a PhD on Pharmaceutical Technology in 2008 and a second PhD in Cellular and Molecular Biology in 2010. In 2013, Amanda obtained a tenured CNRS researcher position. She works on extracellular vesicles and stimulus-responsive nanomaterials for regenerative medicine and antitumor therapy. Amanda has authored 55 papers and 8 patents.
Amanda K. A. Silva (Brun)
PhD on Cellular and Molecular Biology - Université d’Evry /Généthon - Partnership with Faculté de
Pharmacie, Université Paris 5, France (awarded with highest honours);
Supervisors: Otto Wilhelm Merten and Daniel Scherman;
Topic: Thermoresponsive hydrogels for actuated cell attachment and detachment;
|PhD on Pharmaceutical Technology - Health Sciences - Universidade Federal do Rio Grande do Norte,
Department of Biosciences, Natal, Brazil;
Supervisors: Artur da Silva Carriço, Socrates Tabosa do Egito;
Topic: Gastro-resistant polymer-coated magnetic systems for oral route administration;
|MSc on Pharmaceutical Technology - Universidade Federal do Rio Grande do Norte, Department of
Biosciences, Natal, Brazil;
Supervisors: Artur da Silva Carriço, Socrates Tabosa do Egito;
Topic: Design and characterization of micro-clusters of superparamagnetic nanoparticles;
|Pharmacy degree - Universidade Federal do Rio Grande do Norte, Department of Pharmacy, Natal, Brazil;
|Invited lecturer - Nanoscale approaches for regenerative medicine / evaluation of MSc student projects: 15 h/year, Biomedical Engineering Master's Degree Program, Université Paris Descartes and Paris Institute of Technology (ParisTech), Paris, France;
|Invited lecturer - Magnetic nanoparticles for MRI for MSc students: 3 h/year, Master 1, UE 23 (Health track), Faculté de Medicine, Université Paris 7, Paris, France;
|Volunteer monitor - Pharmaceutical Technology for undergraduate students: 50 h/year, Faculté de Pharmacie, Université Paris 5, Paris, France;
|Tutor – English for undergraduate students: 80 h/year, Université d’Evry, Evry, France;
|Lecture trainee - Pharmaceutical Technology for undergraduate students: 100 h/year, Universidade Federal do Rio Grande do Norte, Department of Pharmacy, Natal, Brazil;
|Post-doctoral fellow - Laboratoire Hémostase, Bio-ingénierie et Pathologies Cardiovasculaires,
INSERM U698, Université Paris 7, Université Paris 13;
Topic: Nanobiosystems for therapy of cardiovascular pathologies (D. Letourneur’s team);
|2010 – 2012
|Post-doctoral fellow - Laboratoire "Matière et Systèmes Complexes", Physics Department, Université
Paris 7, CNRS, Paris, France;
Topic: Extracellular vesicles for theranosis (C. Wilhelm and F. Gazeau’s team);
|Co-coordinator of the organising committee - EV thematic school, La Grande Motte, France
|Member of the organising committee - Annual Meeting of the French Society for Nanomedicine (SFNano); 400 attendees; Dijon, France;
|Coordinator - French-Brazilian Workshop on Nanomedicine; 30 attendees, Paris
|Member of the local organising committee - 1st Annual Meeting of the French Society of Extracellular Vesicles (FSEV); 200 attendees; France;
|Vice-coordinator of the French-Brazilian Workshop on Nanomedicine; 50 attendees, France;
|Coordinator of the local organising committee - 3rd Annual Meeting of the French Society for Nanomedicine (SFNano); 230 attendees; Paris, France;
|Member of the organising committee - the Biannual MSC lab Scientific Meeting; 80 attendees, Saint-Valery-sur-Somme, France;
|Coordinator - the French-Brazilian Workshop on Nanomedicine; 20 attendees, Natal, Brazil;
|Member of the local organising committee of the "Journées du Groupe Thématique de Recherche sur les Vecteurs – GTRV", 130 attendees; France;
|Editorial board member of Pharmaceutical Nanotechnology; Journal of Nanotechnology in Diagnosis and
Treatment and International Journal of Molecular Sciences;
Invited guest editor of Advanced Drug Delivery Reviews (IF 13.3);
Evaluator, Cancéropôle Nord-Ouest, France; Agence nationale de la recherché, ANR, France; Dutch Technology Foundation funding agency, The Netherlands; Service de Santé des Armées, France;
Reviewer for the Journal of controlled Release, Theranostics, Journal of Visualized Experiments, Colloids and Surfaces B: Biointerfaces, Cytotechnology, Journal of Drug Delivery Science and Technology, Scientific Reports, Carbon, ACS Nano, etc;
|Elected board member of French Society for Nanomedicine (SFNano) (youngest board member)
|Research and Teaching Excellence Award (4-year duration), CNRS
|Co-founder of Evora Biosciences – Scientific advisor
|Co-founder of EverZom – Scientific advisor
ExocyTher project is based at the laboratory Matière et Systèmes Complexes (Université de Paris, CNRS) in close collaboration with Drs. Florence Gazeau, Dr. Nathalie Luciani and Claire Wilhelm. The main partner is Prof. Dr. Gabriel Rahmi, gastro-enterologist (Hôpital Européen Georges Pompidou, PARCC, INSERM U970, Université de Paris). Dr. Sebastien Banzet, Dr. Christophe Martinaud (CTSA) and Dr. Noëlle Mathieu (IRSN) are also important partners.
Prof. Gabriel Rahmi
Dr. Claire Wilhelm
Dr. Florence Gazeau
Dr. Noëlle Mathieu