Bladder wall biomechanics: A comprehensive study on fresh porcine urinary bladder

Area of Science:

• Biomedical Engineering
• Regenerative Medicine
• Urology

Background:

• Regenerative medicine for reconstructive urogenital surgery is a rapidly advancing field.
• Scaffold mechanical properties are critical for successful bladder regeneration.
• Limited biomechanical data exists for porcine bladder tissue, a common model.

Purpose of the Study:

• To comprehensively evaluate the viscoelastic properties of fresh porcine urinary bladder wall (BW).
• To establish a biomechanical data-base for guiding scaffold design in bladder regeneration.

Main Methods:

• Utilized three testing modes: Uniaxial tensile, ball-burst (BB), and Dynamic Mechanical Analysis (DMA).
• Assessed anisotropic behavior using circumferential and longitudinal BW cut-outs in uniaxial tests.
• Measured viscoelastic properties (storage and loss modulus) via DMA and whole-tissue integrity with BB.

Main Results:

• Porcine bladder wall exhibits anisotropic behavior at strain loads >200%.
• DMA confirmed BW elasticity with storage modulus consistently higher than loss modulus.
• Ball-burst tests showed significantly higher ultimate stress and an average ultimate strain compared to uniaxial tests.

Conclusions:

• The combined biomechanical data from uniaxial, DMA, and BB tests offer a valuable resource for bladder regeneration research.
• Understanding these properties aids in designing functional scaffolds for urogenital reconstructive surgery.