Highly stretchable, injectable hydrogels with cyclic endurance and shape-stability in dynamic mechanical...

Area of Science:

• Materials Science
• Biomedical Engineering
• Polymer Chemistry

Background:

• Traditional injectable hydrogels struggle with large deformation resistance and shape stability under cyclic stress.
• Polyampholyte (PA) hydrogels show promise for large deformation resistance, fatigue resistance, and self-healing, but lack injectability.

Purpose of the Study:

• To develop injectable hydrogels that combine resistance to large deformation and shape stability under cyclic deformation.
• To explore the use of electrostatic interactions for enhanced hydrogel properties.

Main Methods:

• Prepared polyampholyte (PA) hydrogels (as-prepared PA-N) were processed into microunits.
• Microunits were mixed with 0.9% NaCl solution to create reformed injectable hydrogels (as-reformed PA-N) via needle injection.
• Evaluated elongation at break and shape stability under cyclic deformation.

Main Results:

• The as-reformed PA-N hydrogels demonstrated 913.6% elongation at break.
• Excellent shape stability was observed under cyclic deformation, attributed to microunit self-healing and inherited hydrogel structure.
• The reformed hydrogels exhibit superior properties compared to existing tough injectable hydrogels.

Conclusions:

• The developed as-reformed PA-N hydrogels achieve convenient injectability while maintaining resistance to large deformation and shape stability under cyclic conditions.
• Potential applications include dynamic joint movement and mobile wound management.
• This work presents a promising strategy for creating advanced injectable hydrogels.