Robust-adhesion and high-mechanical strength hydrogel for efficient wet tissue adhesion.

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Wound Healing Technologies

Background:

• Bioadhesive hydrogels are promising for wound closure due to minimally invasive application.
• Existing hydrogels often suffer from poor adhesion and mechanical integrity on wet tissues.

Purpose of the Study:

• To develop a ready-to-use bioadhesive hydrogel with enhanced wet adhesion and mechanical properties for wound closure.
• To investigate the adhesion mechanisms and material properties of the novel hydrogel.

Main Methods:

• A one-pot UV crosslinking polymerization of acrylic acid (AA), catechol-functionalized chitosan (C-CS), and acrylic acid N-hydroxysuccinimide ester (AA-NHS ester).
• Characterization of hydrogel mechanical properties (tensile strength, fracture strain, toughness) in swollen state.
• Evaluation of adhesion performance (shear strength, interfacial toughness, burst pressure) on wet porcine skin.

Main Results:

• The PAA-NHS/C-CS hydrogel exhibited high tensile strength (~630 kPa), fracture strain (~1950%), and toughness (~4250 kJ m⁻³).
• Achieved high shear strength (~160 kPa), interfacial toughness (~630 J m⁻²), and burst pressure (~447 mmHg) on wet porcine skin.
• Demonstrated robust adhesion through hydrogen bonds, electrostatic attractions, and dual adhesive moieties (NHS ester and catechol groups).

Conclusions:

• The developed PAA-NHS/C-CS hydrogel offers a promising solution for wound closure with rapid, robust adhesion and high mechanical strength.
• The combination of advanced material properties and ease of use makes this hydrogel suitable for clinical applications in wound management.