#1830 A glomerulus-on-chip to study glomerular cell interactions

Background and Aims The development of effective preventive therapies for glomerulopathy is critically needed. Current pre-clinical research utilizes in vitro 2D cell cultures and in vivo animal models, both of which present significant limitations. Two-dimensional cultures fail to adequately replicate the complex cellular interactions present in physiological environments, while ethical considerations necessitate a reduction in the use of animal models. Although kidney organoid cultures demonstrate enhanced tissue-specific characteristics, they remain insufficient for a comprehensive evaluation of the glomerular filtration barrier (GFB) due to the absence of capillary loop formation. As a complementary approach, the organ-on-chip approach relies on microfluidic to control the organization of the co-culture of differentiated cells [1, 2]. Method We present a glomerulus-on-chip (GoC) fabricated through photolithography, enabling the creation of durable polydimethylsiloxane (PDMS) culture chambers. This model incorporates dual-layer PDMS systems designed to mimic glomerular architecture, featuring dimensional parameters that are consistent with physiological conditions with a 100μm vascular space and a 50μm urinary space. The GoC utilizes three immortalized human cell types: podocytes [3] and parietal epithelial cells (PECs) [4] in the lower chamber, and glomerular endothelial cells (GEnC) [5] cells on the upper side of the porous membrane. Results We propose an innovative opto-microfluidic organ-on-chip, that constitutes a unique integrated system to comprehensively probe complex pathophysiological processes from molecular events to cell/tissue functional behavior in a physiologically relevant environment. Our GoC utilizes immortalized human cell types to reconstitute glomerular organization and facilitate in situ measurements. The model successfully addresses challenges associated with the maturation of the filtration barrier, providing a robust platform for investigating intricate cellular interactions and conducting drug screening. Conclusion Existing commercial systems fail in accurately mimicking the glomerular organization and lack the requisite versatility for systematic screening of diverse stimuli. Our GoC model, characterized by its innovative design and functional filtration capabilities, represents a pivotal advancement in glomerular research. This approach offers a powerful, animal-free platform for pharmacological evaluation and pre-clinical studies, paving the way for novel analyses and therapeutic strategies in kidney pathology.