A double crosslinking adhesion mechanism for developing tough hydrogel adhesives

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Tissue Engineering

Background:

• Tough hydrogel adhesives are promising for biomedical applications due to their mechanical strength and wet tissue adhesion.
• Current covalent conjugation methods for tissue adhesion in hydrogels are limited, restricting material design and potentially raising safety concerns.

Purpose of the Study:

• To report a novel, side-product-free amine-thiolactone chemistry for developing tough hydrogel adhesives.
• To investigate a double crosslinking adhesion mechanism for enhanced bioadhesive properties.

Main Methods:

• Developed thiolactone-bearing tough hydrogels using methacrylate-modified gelatin, acrylic acid, and thiolactone acrylamide.
• Utilized amine-thiolactone chemistry for covalent conjugation with tissue amines via ring-opening and subsequent disulfide bond formation.
• Evaluated hydrogel biocompatibility, mechanical properties, and adhesion to solids and tissues.

Main Results:

• The novel amine-thiolactone chemistry enabled a double crosslinking adhesion mechanism.
• Thiolactone-bearing hydrogels exhibited good biocompatibility and mechanical properties.
• Achieved strong adhesion to various engineering solids and biological tissues, functioning as a tissue sealant and drug depot.

Conclusions:

• The developed amine-thiolactone chemistry provides a versatile and safe platform for creating advanced tough hydrogel adhesives.
• This novel adhesion mechanism diversifies bioadhesive design for applications in hemostasis, drug delivery, and tissue repair.
• The findings facilitate the future development of superior bioadhesives for numerous biomedical applications.