Sequentially Moldable and Bondable Four-Dimensional Hydrogels Compatible with Cell Encapsulation.

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Tissue Engineering

Background:

• Hydrogels are widely used but typically have fixed shapes after formation.
• Existing hydrogel moldability is often limited to precursor injectability, lost post-gelation.
• Hydrogel modulation for shape-fitting and defect-filling is an emerging research area.

Purpose of the Study:

• To develop a compliant, cell-encapsulation-compatible hydrogel with sequential shape alteration capabilities.
• To create a moldable hydrogel from natural polymers using a mild processing strategy.
• To explore the potential of shape-morphing hydrogels for advanced applications.

Main Methods:

• Utilized unmodified natural origin polysaccharides.
• Employed polyelectrolyte complexation followed by partial coacervate compaction and dehydration.
• Demonstrated sequential shape alterations and bonding of hydrogel fragments.

Main Results:

• Achieved a compliant hydrogel capable of extreme sequential shape changes with high mechanical property recovery.
• Successfully bonded different hydrogel fragments into spatiotemporally controlled shape-morphing structures.
• The hydrogel is cell encapsulation-compatible.

Conclusions:

• Presented a novel, moldable hydrogel from affordable natural polysaccharides.
• The developed hydrogel exhibits unique shape-morphing and bonding capabilities.
• Potential applications include defect filling, wound healing patches, cargo release, and cell/tissue delivery.