Mucociliary transference rate and mucus viscoelasticity dependence on dynamic storage and loss modulus

Area of Science:

• Biophysics
• Reproductive Biology

Background:

• Bovine cervical mucus (BCM) is a complex biological fluid with viscoelastic properties crucial for reproductive processes.
• Understanding the rheological behavior of BCM is essential for elucidating its role in sperm transport and fertilization.

Purpose of the Study:

• To investigate the dynamic viscoelastic properties of estrous bovine cervical mucus.
• To determine the relationship between viscoelastic parameters (storage modulus and loss modulus) and the transference rate of particle loads on ciliated epithelium.

Main Methods:

• Collected estrous bovine cervical mucus samples.
• Measured dynamic viscoelastic properties (storage and loss moduli) within a specific frequency range (2.7–4.4 rad/s).
• Modified mucus crosslinking using heat and glutaraldehyde, then reassessed viscoelastic properties.
• Assessed particle load transference rate on frog palate ciliated epithelium.

Main Results:

• Storage modulus increased markedly with increasing loss modulus in native mucus.
• Heat treatment decreased crosslinks, reducing storage modulus, while glutaraldehyde increased crosslinks, raising storage modulus; loss modulus remained largely unaffected.
• Transference rate correlated directly with storage modulus, peaking at 1.6 dynes.cm⁻².
• No correlation was found between transference rate and loss modulus.

Conclusions:

• The storage modulus is the primary determinant of particle transference rate in bovine cervical mucus.
• Alterations in mucus crosslinking significantly impact the storage modulus and, consequently, its transport capacity.
• These findings have implications for understanding reproductive physiology and developing artificial mucus substitutes.