EndoSpray – Efficient cell coating of biohybrid lungs by atomization of shear-stress resistant endothelial cells derived from induced pluripotent stem cells

• Applicants: Dr. Ruth Olmer; Privatdozentin Dr. Anja Lena Thiebes
• Subject Area: Medical Physics, Biomedical Technology ; Cell Biology
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 447712946

Chronic lung disease is one of the most frequent causes of mortality in noncommunicable diseases worldwide with chronic obstructive pulmonary disease (COPD) representing the major share. Exacerbations in patients with severe COPD are often associated with acute respiratory failure with carbon dioxide retention requiring mechanical ventilation. If mechanical ventilation support fails, these patients have to be treated with extracorporeal carbon dioxide removal.Complications associated to those extracorporeal lung support systems comprise inflammatory reactions, hemolysis, bleeding and thrombosis. Thus, its application requires continuous intensive care observation. Furthermore, unspecific protein adsorption to the membrane gradually reduces the efficacy of gas exchange. Both aspects are ascribed to the low hemo and biocompatibility of the gas permeable membranes. Despite significant research activities, the core issue of limited hemocompatibility remains unresolved.To overcome these issues, endothelialization of gas exchange membranes is suggested to form a natural non-thrombogenic surface and allow long-term use of such a biohybrid lung to finally enable implantation. A lot of effort has already been taken on endothelialization of gas exchange membranes but without prove of upscaling feasibility, with sparse data on gas transfer and limited long-term success.In this project, we will evaluate endothelial cell production technologies and membrane seeding techniques for biohybrid lung development. An ideal cell source for endothelialization would be autologous or immunological inert and easy to obtain using a non-invasive collection approach. Furthermore, a substantial proliferation capacity is indispensable to enable production of 1 – 2 billion endothelial cells required for seeding of an oxygenator. Here, human induced pluripotent stem cell-derived endothelial cells (hiPSC-ECs) will be used. Differentiation protocols for targeted generation of hiPSC-ECs displaying an arterial phenotype and thereby higher shear resistance will be addressed in this project as well as protocol optimization for the generation of large cell amounts in stirred tank bioreactors.Cell atomization (spraying) is considered an efficient and universal method to apply cells to various substrates. For seeding of endothelial cells, atomization is proposed to produce a uniform cell layer on gas exchange membranes. In this project, we will evaluate mid- and long-term behavior of hiPSC-ECs after atomization especially under dynamic culture.With the described techniques, a proof-of-concept with long-term evaluation of an endothelialized laboratory oxygenator model will be accomplished in this project.

• DFG Programme: Priority Programmes
• Subproject of: SPP 2014: Towards an Implantable Lung
• Co-Investigator: Privatdozent Dr. Christian Cornelissen