Human Laryngeal Mucus from the Vocal Folds: Rheological Characterization by Particle Tracking Microrheology and...

Area of Science:

• Biophysics
• Otorhinolaryngology
• Rheology

Background:

• Mucus consistency impacts voice physiology and is linked to voice disorders.
• The rheological properties of human laryngeal mucus from vocal folds are largely unknown.
• Understanding mucus viscoelasticity is crucial for developing artificial mucus, improving experimental models, and treating voice disorders like dysphonia.

Purpose of the Study:

• To characterize the viscoelasticity of human laryngeal mucus from vocal folds.
• To investigate the relationship between mucus rheology and factors like hydration and smoking behavior.
• To establish a basis for improved understanding and treatment of voice disorders related to mucus.

Main Methods:

• Collected human laryngeal mucus samples from vocal fold patients.
• Employed two complementary rheological techniques: particle tracking microrheology (PTM) and oscillatory shear rheology (OSR).
• Analyzed mucus samples for viscoelastic properties (G' and G″) and correlated findings with demographic data, including smoking behavior.

Main Results:

• Significant diversity in mucus viscoelasticity (rigidity) was observed among samples.
• Samples exhibited either solid-like (G' > G″) or transitioned from solid-like to liquid-like (G' < G″) behavior, leading to three distinct groups.
• Mucus with predominantly liquid-like character was associated with current smokers.
• No significant correlation was found between demographic data (excluding smoking) and mucus viscoelasticity differences.

Conclusions:

• Human laryngeal mucus exhibits varied viscoelastic properties, likely influenced by hydration levels affecting mucin concentration and network formation.
• Smoking behavior is a potential factor influencing vocal fold mucus rheology, with smokers exhibiting more liquid-like mucus.
• These findings provide foundational knowledge for understanding mucus-related voice disorders and developing targeted therapeutic strategies.