Construction of a three-dimensional urothelium on-chip with barrier function based on urinary flow microenvironment

Area of Science:

• Biomedical Engineering
• Urology
• Cell Biology

Background:

• The urothelium forms a critical barrier in the urinary tract.
• Dysfunction of this barrier is linked to various diseases.
• A 3D model is needed to study urothelial pathophysiology under fluid shear stress.

Purpose of the Study:

• To develop a functional 3D urothelium-on-chip model.
• To simulate physiological fluid shear stress from urinary flow.
• To investigate urothelial cell behavior under simulated urinary tract conditions.

Main Methods:

• Fabrication of a microfluidic chip using micromilling and replica molding.
• Culturing cells within a gelatin methacrylate hydrogel mimicking urinary tract mechanical properties.
• Implementing a pump-based perfusion system to provide pulsatile and periodic flow.

Main Results:

• The model successfully simulated the 3D urothelium structure and urinary flow microenvironment.
• Physiological fluid shear stress promoted urothelial cell differentiation and maturation.
• The model exhibited morphological characteristics and functional markers (uroplakin 2, cytokeratin 20) similar to natural urothelium, indicating barrier function.

Conclusions:

• The developed urothelium-on-chip model is a valuable tool for studying urinary tract diseases.
• Simulated physiological fluid shear stress enhances urothelial cell differentiation and barrier function.
• This model accurately replicates the native urothelium's structure and function in vitro.