Gels That Serve as Mucus Simulants: A Review

Area of Science:

• Biomaterials Science
• Immunology
• Polymer Chemistry

Background:

• Mucus is a vital component of the immune system, trapping pollutants, allergens, and pathogens.
• Synthetic hydrogels are developed to emulate mucus' protective functions.
• Key challenges include replicating mucus' rheological properties and particle-capturing adhesion mechanisms.

Purpose of the Study:

• To review existing synthetic mucus simulants.
• To analyze their rheological, adhesive, and tribological characteristics.
• To identify simulants that effectively mimic mucus' functional properties.

Main Methods:

• Literature review of synthetic mucus hydrogels.
• Analysis of rheological properties (storage modulus vs. loss modulus).
• Evaluation of adhesive properties and their role in particle capture.

Main Results:

• Most reviewed hydrogels exhibit mucus-like rheological properties, with storage modulus exceeding loss modulus.
• Rheological values of most simulants fall within the range observed in natural mucus.
• Only Polyvinyl alcohol-Borax hydrogel successfully mimics the adhesive properties crucial for particle capture.

Conclusions:

• While many synthetic hydrogels replicate mucus' flow properties, few replicate its adhesive functions.
• Polyvinyl alcohol-Borax hydrogel stands out for its ability to mimic mucus' adhesive mechanism.
• Further development is needed to create comprehensive mucus simulants for biomedical applications.