Preclinical development of engineered biomaterial-based artificial bladder demonstrating core functions in a large-animal orthotopic model.

This study demonstrates an artificial bladder that restores urine storage, sensing, and controlled voiding by integrating engineered biomaterials. It comprises a main body for urine storage, a pressure control system for voiding, and a wireless, battery-free urine fullness sensor. The main body consists of an outer wall and a thin septum membrane. The outer wall is fabricated using poly(dimethylsiloxane)(PDMS) and Ecoflex (Smooth-On, Inc.) to achieve both mechanical strength and flexibility, with a Parylene-C coating ensuring biocompatibility. Inside, a diagonally positioned septum membrane separates the urine storage and working fluid compartments. Reinforced with a glass fiber mesh, this membrane allows controlled deformation and stable pressure regulation. The sensor, integrated into the bladder wall, enables wireless urine volume monitoring without an internal power source. The outer wall and pressure control system, including a manual pump and on/off valve, are fabricated using 3D-printed molds. In vitro simulation and in vivo experiments with mini pigs for 6 weeks demonstrated that the artificial bladder mimics human bladder function successfully, while maintaining stable storage pressure and generating sufficient voiding pressure via an external pump. Post-implantation analysis confirmed biocompatibility, structural stability, and secure urinary tract connection. These findings highlight the potential of biomaterial-based artificial organs in restoring bladder function.