Mechanically Reinforced Catechol-Containing Hydrogels with Improved Tissue Gluing Performance

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Adhesive Technology

Background:

• In situ forming hydrogels with catechol groups are bioinspired materials for tissue adhesion.
• Poly(ethylene glycol) (PEG)⁻catechol tissue glues are promising but often lack mechanical stability for load-bearing applications.
• Optimizing cross-linking mechanisms and conditions is crucial for PEG-catechol systems.

Purpose of the Study:

• To develop mechanically reinforced PEG⁻catechol adhesives with enhanced cohesive and adhesive properties.
• To improve the performance of tissue adhesives for load-bearing surgical applications.
• To create tunable bioinspired adhesives that perform well in the presence of blood.

Main Methods:

• Formulation of composite hydrogels using collagen/PEG mixtures, with optional hydroxyapatite nanoparticles.
• Characterization of mechanical performance and adhesion strength of the composite hydrogels.
• Evaluation of adhesive performance on tissue in the presence of blood, comparing with existing adhesives.

Main Results:

• Composite hydrogels exhibited significantly improved mechanical performance compared to individual components.
• Adhesion strength on blood-covered skin exceeded 40 kPa, surpassing cyanoacrylate, fibrin, and standard PEG⁻catechol systems by over sixfold.
• Mechanical and interfacial properties were tunable by adjusting the composite composition.

Conclusions:

• Mechanically reinforced PEG⁻catechol adhesives offer excellent and tunable cohesive and adhesive properties.
• These advanced adhesives show great potential for load-bearing surgery and challenging in-vivo conditions.
• The developed composite hydrogels represent a significant advancement in bioinspired tissue adhesives.