Velcro-Inspired Poly(ethylene glycol) Gel (PEGgel) for Robust Interface Adhesion Between Hydrogel, Device, and Tissue

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Polymer Chemistry

Background:

• Hydrogel bioadhesives are crucial for tissue engineering and flexible electronics due to their biocompatibility and mechanical properties.
• A key limitation is the difficulty in tuning hydrogel mechanical properties to match diverse biological tissue strengths.

Purpose of the Study:

• To develop a novel, tunable hydrogel bioadhesive with adjustable mechanical properties for various tissue engineering applications.
• To overcome the limitations of existing bioadhesives in matching specific tissue mechanical strengths.

Main Methods:

• A poly(methacrylamide-polyethylene glycol-N-hydroxysuccinimide ester-co-acrylic acid) PEGgel (MAP) bioadhesive was synthesized using a drying cross-linking mechanism.
• The molecular weight and proportion of the polyethylene glycol (PEG) solvent were modified to tune the hydrogel's mechanical properties.

Main Results:

• MAP demonstrated adjustable tensile strength (130 kPa to 1 MPa) and fracture strain (149% to 2653%) by altering PEG characteristics.
• MAP exhibited robust adhesion to tissues and substrates, with shear strengths of 130 kPa on pigskin and 6.8 MPa on glass.
• Successful applications in tendon healing and movement monitoring showcased MAP's tough and compliant adhesion.

Conclusions:

• MAP bioadhesives offer tunable mechanical properties, robust adhesion, and long-term storage capabilities.
• The material's 3D-printability, self-healing ability, and biocompatibility make it a promising candidate for advanced bioadhesive development.
• MAP addresses the challenge of matching bioadhesive mechanical properties to diverse tissue strengths, expanding its utility in biomedical fields.