Trace-stimuli-triggered controlled degradation for hydrogel adhesives.

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Tissue Engineering

Background:

• Biodegradable hydrogels are limited by harsh degradation triggers and uncontrolled breakdown.
• Existing hydrogels often lack precise control over degradation rates and timing.
• This limits their application in sensitive biomedical contexts like tissue adhesion and coatings.

Purpose of the Study:

• To develop a novel biodegradable hydrogel strategy with spatiotemporally controlled degradation.
• To utilize a redox-responsive crosslinker with a low activation threshold for precise degradation control.
• To enhance hydrogel performance as tissue adhesives and implantable coatings.

Main Methods:

• Designed hydrogels using a redox-responsive crosslinker sensitive to reactive oxygen species (ROS).
• Investigated hydrogel degradation kinetics at various ROS concentrations and temperatures.
• Evaluated hydrogel performance as a tissue adhesive in vitro and in vivo, assessing bond strength, adhesion, and sealing capabilities.
• Assessed degradation profiles under physiological ROS concentrations.

Main Results:

• Hydrogels demonstrated rapid and complete degradation within 2 hours at 0.1% ROS and 24 hours at 0.0001% ROS.
• Achieved strong wet adhesion (200 J/m²) and rapid bonding (within 5 s) as a tissue adhesive.
• Showcased excellent sealing performance in vitro and in vivo models.
• Degraded completely over 3 weeks under physiological ROS concentrations, aligning with wound healing timelines.
• Observed initial degradation triggering chain growth, reinforcing adhesion and compensating for swelling.

Conclusions:

• The developed hydrogel strategy enables precise, ROS-triggered degradation with a low activation threshold.
• These hydrogels function effectively as tissue adhesives with strong, rapid adhesion and excellent sealing properties.
• The degradation profile aligns with natural healing processes, minimizing risks of synthetic residue and contamination.
• This approach offers a versatile and biocompatible platform for advanced biodegradable materials in clinical applications.