Microfluidic bioprinting towards a renal in vitro model

It is estimated that 10% of the worldwide population suffers from chronic kidney disease (CKD) with a rising tendency. Patients with CKD have limited treatment options and novel therapies that could halt or even reverse the progression of CKD are urgently needed. Bioprinting is considered one of the most promising approaches to generate novel 3D in vitro models and organ-like constructs to investigate underlying pathomechanism of kidney diseases. This study aimed at establishing a method to isolate primary renal cells in an easy and reproducible way. These cells were used in a new bioprinting platform laying the foundation for the development of a 3D renal tubulointerstitium model for in vitro studies. Primary murine tubular (pmTECs), endothelial and fibroblast cells were successfully isolated, but further optimization is required for the culture and expansion of primary endothelial cells. Therefore, an endothelial cell line (HUVECs) and pmTECs were combined with polysaccharide biomaterial ink solutions and processed with a microfluidic 3D bioprinter, leading to high cell viability and metabolic activity. Core-shell bioprinted constructs with HUVECs and pmTECs were manufactured mimicking tubules. In conclusion, microfluidic bioprinting strategy could be used to build a novel 3D kidney in vitro model.