Mucus-Mimicking Mucin-Based Hydrogels by Tandem Chemical and Physical Crosslinking

Area of Science:

• Biomaterials Science
• Pharmaceutical Sciences
• Drug Delivery

Background:

• Mucosal tissues are key interfaces, protected by mucus, a hydrated mucin gel.
• Mucus is vital for lubrication, protection, and moisture regulation.
• Native mucosal membranes are often used in pharmaceutical research for mucoadhesion and muco-penetration studies, but face accessibility, reproducibility, and ethical challenges.

Purpose of the Study:

• To develop a platform for studying drug and delivery system interactions with mucosal tissues.
• To synthesize mucus-mimicking hydrogels using mucin.

Main Methods:

• Mucin aqueous solutions were crosslinked using both chemical (glutaraldehyde) and physical (freeze-thawing) methods.
• Hydrogel properties including water content, density, and mechanical moduli were characterized.
• Comparison of synthesized hydrogels with native gastrointestinal mucus properties.

Main Results:

• Hydrogels synthesized with one freeze-thawing cycle exhibited high water content (97.6-98.1%) and low density (0.0529-0.0648 g cm⁻³).
• These hydrogels possessed storage and loss moduli (≈40-60 Pa and ≈3-5 Pa, respectively) comparable to native gastrointestinal mucus.
• Mechanical stability of the hydrogels increased with additional freeze-thawing cycles.

Conclusions:

• The study presents a simple, reproducible, and scalable method for creating artificial mucus-mimicking hydrogels.
• These mucin-based hydrogels show promise as an alternative to animal tissues for pharmaceutical research.
• The developed hydrogels have potential applications in evaluating mucoadhesion and muco-penetration of drug delivery systems.