Self-reinforceable poly(lipoic acid)-based tough underwater tissue bioadhesive

Area of Science:

• Materials Science
• Biomedical Engineering
• Polymer Chemistry

Background:

• Achieving strong bioadhesive bonding on wet or underwater tissues is difficult due to hydration layers and swelling.
• Existing bioadhesives struggle to maintain adhesion in wet environments, limiting their biomedical applications.

Purpose of the Study:

• To engineer a novel bioadhesive capable of self-hardening in water for enhanced wet/underwater tissue adhesion.
• To investigate the adhesion strength, cohesion, and stability of the developed bioadhesive in wet conditions.
• To explore the integration of this bioadhesive into a strain sensor for wet environment applications.

Main Methods:

• A water-induced self-hardening bioadhesive (p(LA-ABO)) was synthesized using poly(lipoic acid) (PolyLA) and 4-allyl-1,2-benzenediol (ABO) via solvent evaporation-induced self-polymerization.
• Underwater curing was performed, and the bioadhesive's properties were evaluated, including tensile strength, adhesion strength on wet porcine skin, swelling, and detachment.
• A strain sensor was fabricated by integrating the bioadhesive with a conductive fabric for body motion sensing.

Main Results:

• The bioadhesive demonstrated a significant increase in tensile strength (57.77 to 93.87 kPa) and adhesion strength on wet porcine skin (50.48 to 80.59 kPa) within 6 hours.
• Robust underwater adhesion (∼85.09 kPa) was maintained after 6 hours, with minimal swelling (∼1.1%) after 12 hours of water immersion.
• The fabricated strain sensor exhibited high conductivity and sensitivity for detecting body motion signals in wet conditions.

Conclusions:

• The developed water-induced self-hardening bioadhesive provides durable and robust adhesion on wet/underwater tissues, overcoming limitations of existing materials.
• The bioadhesive exhibits excellent biocompatibility, biodegradability, and on-demand detachment capabilities.
• This technology offers a promising new platform for developing advanced biosensors for wet and underwater applications.