Application and Mechanism of Bionic Leaf Vein Chip in the Construction of Bioartificial Kidney

Background: Bioartificial kidneys represent an emerging frontier in regenerative medicine and bioengineering, with particular emphasis on the development of functional bioreactors that recapitulate native renal transport mechanisms. In this study, we designed and constructed a bioartificial renal tubular bioreactor based on a bionic microfluidic chip inspired by leaf vein architectures. This system aims to replicate the physiological microenvironment of renal tubules and offers a novel in vitro platform for the advancement of wearable or implantable bioartificial kidney technologies.
Methods: Conditionally immortalized human renal proximal tubular epithelial cells (PTCs) were established via lentiviral transduction. A bionic microfluidic chip featuring leaf vein-like channel networks was fabricated using photolithography and soft lithography techniques. PTCs were seeded and cultured within the chip, and their morphology, functional activity, and expression of key transporter proteins were characterized through computational hydrodynamic simulation, immunofluorescence staining, and laser confocal microscopy. The transport efficiency of glucose, organic anions, and albumin was evaluated within the bioreactor system.
Results: Two generations of biomimetic renal tubular chips were successfully developed based on the leaf vein-inspired microfluidic platform. In the first-generation chip, PTCs cultured under three-dimensional (3D) conditions exhibited enhanced reticular morphology and improved viability compared to conventional two-dimensional (2D) cultures, indicating superior tubulogenic capacity. These cells also showed upregulated expression of key transporters, including SGLT and OAT3. The second-generation chip integrated vascular endothelial cells within the vein-mimetic channels and PTCs in the parenchymal compartment. Upon co-culture, a 3D reticular architecture was formed, further enhancing the tubulogenic potential of PTCs and increasing the expression of GLUT2 and AQP1. In the third-generation chip, human podocytes were co-cultured alongside PTCs. Following seeding, podocytes exhibited morphological alterations and reduced immunoreactivity for the podocyte-specific marker WT-1. In contrast, PTCs retained robust tubulogenic capacity and continued to express characteristic proximal tubular markers.
Conclusion: We have successfully engineered two types of renal tubule-on-a-chip platforms based on a leaf vein-inspired microfluidic design, which closely mimic the physiological microenvironment of the proximal tubule. PTCs cultured in these 3D systems demonstrated enhanced biological activity and reabsorptive function compared to 2D controls, with markedly improved tubular epithelial morphology. These biomimetic chips offer a powerful experimental platform to advance the development of bioartificial kidneys and facilitate mechanistic studies of the renal microenvironment.