Interfacial fluid transport is a key to hydrogel bioadhesion

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Adhesion Science

Background:

• Attaching hydrogels to soft internal tissues is essential for biomedical devices.
• The wet nature of hydrogels and tissues presents significant challenges for achieving and controlling adhesion.

Purpose of the Study:

• To investigate the role of fluid transport across hydrogel-tissue interfaces in determining adhesion strength.
• To understand the transition between different adhesion regimes based on interfacial fluid dynamics.

Main Methods:

• Ex vivo peeling experiments on porcine liver using model hydrogel membranes.
• Systematic variation of contact time, tissue hydration, and hydrogel swelling ratio.
• In vivo experiments on actively hydrated tissues and evaluation of superabsorbent hydrogel meshes.

Main Results:

• Identified two distinct peeling regimes: lubricated (low adhesion energy) and adhesive (high adhesion energy).
• Demonstrated that interfacial fluid draining induces local tissue dehydration, promoting intrinsic adhesion.
• Validated a model based on tissue microanatomy and confirmed findings in vivo.

Conclusions:

• Interfacial fluid transport is a key determinant of hydrogel-tissue adhesion.
• Adhesion can be significantly enhanced by controlling fluid dynamics and inducing local tissue dehydration.
• Findings inform the design of improved bioadhesion tests and strategies for biomedical applications.