Development of an upscaled bioartificial kidney

The development of cell based bioartificial kidney (BAK) could improve existing dialysis therapies for the removal of protein-bound toxins. A key requirement for the BAK is the formation of a “living membrane” consisting of a tight renal cells monolayer with preserved functional organic ion transporters, on an artificial porous membrane.The main aim of this thesis is to develop an upscaled BAK prototype, making use of conditionally immortalized human proximal tubule epithelial cells (ciPTEC), seeded on functionalized hollow fiber membranes (HFM).
First, we develop an optimal coating on the external surface of a commercially available HFM module. CiPTEC are seeded and cultured under static conditions on the functionalized HFM. We prove that this living membrane exhibits a uniform, reproducible and tight ciPTEC monolayer, on the outside surface of the HFM. Importantly, ciPTEC cultured in this upscaled system feature active organic transporters, crucial for the removal of uremic cationic metabolites and anionic toxins, such as indoxyl sulfate (IS). Furthermore, we study the immune response of the ciPTEC and show that they are fully polarized. The pro-inflammatory cytokines are mainly released towards the dialysate compartment, which would greatly reduce risks associated with eventual pro-inflammatory and immunogenic effects of the ciPTEC. Furthermore, we present strategies for achieving a good quality ciPTEC monolayer on the inside surface of the HFM. This configuration could be preferred for the development of a clinically relevant BAK due to a better preservation of the cell monolayer against friction and to a greater similarity with the natural proximal tubule. Finally, we also study the ability of alternative polymeric flat surfaces to support the formation of a “living membrane”. Overall, this thesis presents a successfully upscaled BAK device. Complementary testing of this system in vitro as well as modelling would lead to a clinically relevant device.