Rapid Ultratough Topological Tissue Adhesives

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Adhesion Science

Background:

• Achieving strong and tough adhesion in wet biological environments is crucial for biomedical applications.
• Existing tissue adhesives, whether covalent or non-covalent, often suffer from limitations such as weak, unstable, or slow adhesion.

Purpose of the Study:

• To develop a novel tissue adhesive capable of strong and tough adhesion in wet conditions without relying on covalent bond formation.
• To investigate the mechanism behind the adhesion and optimize adhesive properties for biomedical use.

Main Methods:

• Combining pH-responsive bridging chitosan polymer chains with a tough hydrogel dissipative matrix.
• Investigating the influence of chitosan molecular weight, matrix polymer molecular weight, and pH on adhesion.
• Exploring hydrogel dehydration to accelerate adhesion time.

Main Results:

• Achieved unprecedented ultratough adhesion to tissues (>2000 J m⁻²) within 5-10 minutes without covalent bonding.
• Demonstrated stable adhesion under physiologically relevant conditions.
• Showcased rapid adhesion (>1000 J m⁻² in ≤1 minute) through hydrogel dehydration, facilitating chitosan interpenetration and entanglement.

Conclusions:

• A novel non-covalent tissue adhesive based on chitosan and hydrogels offers superior adhesion properties.
• The mechanism relies on topological entanglement, influenced by polymer characteristics and pH.
• This technology presents new opportunities for developing advanced tissue adhesives for diverse bioapplications.