MetaDyn

Animal models are used for disease modeling, but beyond ethical concerns and costs, their relevance is limited due to differences between the main model species and humans. Therefore, the development of in vitro 3D human models that mimic the complex architecture and function of tissues is crucial for the development of new therapies. MetaDyn aims to develop a model of perfused tissue to study fibrotic muscular pathologies. For the first time, the detrimental effects of fibrosis, such as high stiffness and impaired perfusion, will be taken into account and compared to changes in cellular behavior. The cellular response to fibrosis will be analyzed in real time using live, unlabeled samples via state-of-the art dynamic optical coherence tomography (D OCT). The unique sensitivity of this technique will allow for the analysis of the cell cycle, metabolism, and extracellular matrix remodeling. The project’s originality and strength rely on the consortium’s expertise in collagen 3D printing, biomicrofluidics and optics. On this basis, we will design matrices with the physical properties and porosity of healthy and fibrotic muscular extracellular matrix, which has never been achieved so far. To design fibrotic matrices, the porosity of the healthy matrix will be reduced to settle hypoxia, and stiffness will be increased by cross-linking. Then, macroporosity dedicated to cell colonization will be generated using a sacrificial matrix to allow a large number of myoblasts to colonize. First C2C12 mouse myoblasts will be used to improve the protocol of cellularization. Then, cell colonization will be performed with cell lines of human myoblasts from patients affected by Duchenne Muscular Dystrophy. Finally, the perfusion of healthy and fibrotic muscle models will be implemented using a microfluidic chip to mimic the physiological conditions. The impact of impaired perfusion and matrix stiffness on cellular behavior will be studied. This ambitious project addresses key biological questions, such as the relationship between matrix properties and hypoxic stress or the impact of stiffness on cellular behavior, allowing for a better understanding of muscular dystrophies and the identification of suitable therapeutic targets.