Murine bladder wall biomechanics following partial bladder obstruction.

Area of Science:

• Biomedical Engineering
• Urology
• Materials Science

Background:

• Evaluating bladder wall mechanical behavior is crucial for understanding functional changes in conditions like partial bladder outlet obstruction (pBOO).
• Traditional cystometry is challenging in murine models due to small bladder capacity and surgical exposure difficulties.
• Biaxial mechanical testing offers an alternative for characterizing murine bladder mechanical properties.

Purpose of the Study:

• To explore biaxial mechanical testing as an alternative method for assessing murine bladder mechanical properties.
• To quantify the changes in bladder mechanics following partial bladder outlet obstruction (pBOO) in a murine model.
• To differentiate mechanical property changes between fibrotic and distended bladder phenotypes post-pBOO.

Main Methods:

• Murine bladders from female C57/Bl6 mice subjected to partial bladder outlet obstruction (pBOO) for 4 weeks were analyzed.
• Control bladders from age-matched mice were used for comparison.
• Biaxial mechanical testing was performed in modified Kreb's solution at 37°C, evaluating axial strain at 50kPa after preconditioning.

Main Results:

• Normal murine bladders demonstrated anisotropy, being stiffer longitudinally.
• All mice with pBOO exhibited a loss of anisotropy.
• Fibrotic bladders showed reduced extensibility, while distended bladders displayed increased extensibility compared to controls.

Conclusions:

• Partial bladder outlet obstruction (pBOO) induces significant, quantifiable changes in murine bladder mechanics.
• Biaxial testing effectively quantifies these mechanical alterations, including anisotropy and extensibility changes.
• This method provides a valuable tool for studying bladder pathophysiology in murine models.