A fundamental limitation with current approaches aiming to bioprint tissues and organs is an inability to generate constructs with truly biomimetic composition and structure, resulting in the development of engineered tissues that cannot execute their specific function in vivo. This is perhaps unsurprising, as many tissues and organs continue to mature postnatally, often taking many years to attain the compositional and structural complexity that is integral to their function. A potential solution to this challenge is to engineer tissues that are more representative of an earlier stage of development, using bioprinting to not only generate such constructs, but to also provide them with guiding structures and biochemical cues that supports their maturation into fully functional tissues or organs within damaged or diseased in vivo environments. It has recently been demonstrated that such developmental processes are better recapitulated in ‘microtissues’ or ‘organoids formed from self-organizing (multi)cellular aggregates, motivating their use as biological building blocks for the engineering of larger scale tissues and organ. The main goal of micro2MACRO (m2M) is to develop a new bioprinting platform capable of spatially patterning numerous cellular aggregates or microtissues into scaled-up, personalised durable load-bearing grafts and guiding their (re)modelling into fully functional tissues in vivo within damaged or diseased environments. This will be achieved using a converged bioprinting approach capable of rapidly depositing cells and microtissues into guiding scaffold structures with high spatial resolution in a rapid, reliable, reproducible and quantifiable manner. These guiding structures will then function to direction the fusion and remodelling of cellular aggregates and microtissues into structurally organised tissues in vitro and in vivo, as well as providing medium-term (3-5 years) mechanical support to the regenerating tissue.

Our project focuses on the regulatory properties of a subset of microbiota-specific TR1-like regulatory T (Treg) cells, for which we have already shown an unprecedented association with the clinical outcome of patients in various inflammatory diseases, for a therapeutic use in inflammatory bowel diseases (IBD). IBD is a disabling chronic inflammatory process that affects young individuals and causes many life-altering symptoms, and represents a risk factor for colon cancer. Existing treatments are complex, with most people requiring lifelong medications as well as dietary and lifestyle modifications, and some requiring surgery. In this context, the development of new therapeutic approaches appears essential and immunotherapy and cell-based therapy are particularly promising strategies for this disease. Teams from Nantes have a strong expertise in the field of human immunology, mucosal immunology and immunotherapeutic strategies applied to various pathological conditions, including gut inflammatory diseases. They recently identified a novel microbiota-induced Treg subset, associated with good prognosis in IBD patients, thus representing a promising candidate for innovative immunotherapeutic approaches. Based on the limitation to develop immunotherapy approach for human diseases by using animal models due to immune system specificities/differences and ethical considerations, we opted for the development of an ex vivo human preclinical model that will reconstitute the physiological complexity of the human gut. Teams from Strasbourg have a strong experience and already set-up models of organoids in different pathological systems, that will perfectly fit to be used as ex vivo preclinical models for this project. This proposal aims thus at providing a pre-clinical package including i) the proof of concept that a cellular immunotherapy using the identified Tregs subset represents a treatment for IBDs and ii) the reglementary pre-clinical in vitro and in vivo toxicity.

Bioprinting in Space is one of the novel promising and perspective research directions in the rapidly emerging field of biofabrication. There are several advantages of bioprinting in Space. First, under the conditions of microgravity, it is possible to bioprint constructs employing more fluidic channels and, thus, more biocompatible bio-inks. Second, microgravity conditions enable 3D bioprinting of tissue and organ constructs of more complex geometries with voids, cavities, and tunnels. Third, a novel scaffold-free, label-free, and nozzle-free technology based on multi-levitation principles can be implemented under the condition of microgravity. The ideal Space bioprinters must be safe, automated, compact, and user friendly. Thus, there are no doubts that systematic exploration of 3D bioprinting in Space will advance biofabrication and bioprinting technology per se. Vice versa 3D bioprinted tissues could be used to study pathophysiological biological phenomena when exposed to microgravity and cosmic radiation that will be useful on Earth to understand ageing conditioning of tissues, and in space for the crew of deep space manned missions. In PULSE, we aim at developing a radical new bioprinting technology based on multiple levitation principles and to use Space as an accelerator of ageing on Earth. As a proof of concept, we will use this newly developed bioprinting technology to create cardiac 3D in vitro models able to better mimic cardiac physiology compared to organoids. We will use such models to study cardiac ageing and test the efficacy of antiinflammatory/ anti-oxidative drugs with anti-ageing potential. In the Hop-On PULSE project, META will be introducing their platelet-derived and placenta-derived hydrogels, which are beneficial to the consortium for 2 key aspects: 1) they will provide more easily a biological environment able to recapitulate the microenvironment needed for cardiac tissue engineering; 2) they will provide a solution for construct storage.

Despite extensive preclinical in vitro and animal screening tests, >90% of new drugs still fail in clinical trials. Key issues of lack of efficacy (40-60%) and toxicity (30%) in humans are still not sufficiently predicted in cell culture and non-human in vivo tests (animal models are just 50% accurate on average). The issue wastes years of development time and billions of Euros on unsuccessful therapies. The EMA and FDA recognise this problem and welcome novel technologies as alternatives to animal testing with more accurate predictive value to humans. However, a solution that meets industry needs does not currently exist. To meet this need, researchers and the pharmaceutical industry need an in vitro human tissue analogue that is (i) 3D, (ii) compositionally identical to human tissue, and (iii) has accurate physico-mechanical properties (stiffness, elasticity) that can be tuned to represent different tissue environments. Inability to mimic these environments leads to cellular behaviour not seen in vivo. Metatissue has the only biomatrix technology that meets all key user requirements. Derived from sustainable human platelet lysates, our technology ‘hPLMA’ can be used across 3D culture, bioink and organ-on-chip models. hPLMA most closely represents human tissue, through a 3D, human-derived, xeno-free biomatrix that can be tailored to represent any tissue physiology. It eliminates potential immune reactions to animal proteins and residual DNA/disease-causing prions and viruses. Researchers could significantly reduce use of animals in research and save billions in drug development costs with our practical and scalable solution. Our technology is patent protected, funded to TRL6 with the support of the ERC and Horizon 2020. This is a multibillion Euro market, with hPLMA revenues of €32 million forecast within 5 years of market entry. With EIC support we can complete our scale-up and extended user trials, and achieve full market readiness.

Our project focuses on the regulatory properties of a subset of microbiota-specific TR1-like regulatory T (Treg) cells, for which we have already shown an unprecedented association with the clinical outcome of patients in various inflammatory diseases, for a therapeutic use in inflammatory bowel diseases (IBD). IBD is a disabling chronic inflammatory process that affects young individuals and causes many life-altering symptoms, and represents a risk factor for colon cancer. Existing treatments are complex, with most people requiring lifelong medications as well as dietary and lifestyle modifications, and some requiring surgery. In this context, the development of new therapeutic approaches appears essential and immunotherapy and cell-based therapy are particularly promising strategies for this disease. Teams from Nantes have a strong expertise in the field of human immunology, mucosal immunology and immunotherapeutic strategies applied to various pathological conditions, including gut inflammatory diseases. They recently identified a novel microbiota-induced Treg subset, associated with good prognosis in IBD patients, thus representing a promising candidate for innovative immunotherapeutic approaches. Based on the limitation to develop immunotherapy approach for human diseases by using animal models due to immune system specificities/differences and ethical considerations, we opted for the development of an ex vivo human preclinical model that will reconstitute the physiological complexity of the human gut. Teams from Strasbourg have a strong experience and already set-up models of organoids in different pathological systems, that will perfectly fit to be used as ex vivo preclinical models for this project. This proposal aims thus at providing a pre-clinical package including i) the proof of concept that a cellular immunotherapy using the identified Tregs subset represents a treatment for IBDs and ii) the reglementary pre-clinical in vitro and in vivo toxicity.