Nanoscience and nanotechnology are currently revolutionizing sectors such as medicine, information technologies, environmental or materials sciences, and creating new opportunities for our societies. In this context, magnetic nanoparticles (MNP) are key components to the development of novel nano- and biotechnologies. Magnetosomes are unique hybrid magnetic MNP produced by magnetotactic bacteria (MB). They are employed in applications ranging from extraction of DNA to the development of immunoassays and uses in spintronics are envisaged. However, only a very limited amount of MNP (few mg per day) can be formed by MB, and the formation principles remain to be tackled. Biomimetics, i.e. combining biological principles with chemistry, will pave the way to understand biomineralization of tailored MNP and to find out high-value high-yield synthetic routes to solve scientific and technological challenges. Specifically, we aspire at bridging the gap between different fields of science. For the first time, we will blend biological and genetic approaches with chemical and physical knowledge to understand the key parameters controlling the size, shape, composition and assembly of hybrid MNP in vivo and in vitro. We will combine nanoscience and nanotechnology to modify these properties and develop an ensemble of magnetic nanomaterials of higher values. This approach will lead to original contributions of innovative nature based on the combined skills of the partners to manufacture and characterize the biological, chemical, structural and magnetic properties of the MNP. The industrial partner will have key importance in managing and assessing the applicability of the MNP in Magnetic Resonance Imaging (MRI). Finally, our cell biologist partner will test the biocompatibility of the designed systems. In 3 years, we aim at being able to synthesize hybrid MNP with tailored magnetic and size properties by low-cost high-yield synthesis for applications in MRI.