Engineering shape memory and morphing protein hydrogels based on protein unfolding and folding

Area of Science:

• Biomaterials Science
• Protein Engineering
• Materials Science

Background:

• Polymer-based shape memory/morphing materials have advanced significantly.
• Engineering protein-based shape memory/morphing materials is challenging and underexplored.

Purpose of the Study:

• To design and fabricate a novel bilayer protein-based shape memory/morphing hydrogel.
• To explore the protein folding-unfolding mechanism for material shape transformation.

Main Methods:

• Fabrication of a bilayer hydrogel using tandem modular elastomeric proteins (GB1)8 and (FL)8.
• Characterization of distinct denaturant-dependent swelling profiles and Young's moduli for each protein layer.
• Investigation of protein unfolding-folding induced swelling changes for tunable deformation.

Main Results:

• The bilayer hydrogels exhibit tunable and reversible bidirectional bending deformation controlled by denaturant concentration and layer geometry.
• Programmable and reversible bending behaviors were demonstrated.
• The protein-bilayer structure was utilized as a hinge for 1D to 2D and 2D to 3D folding transformations of patterned hydrogels.

Conclusions:

• The study presents a novel protein-based shape memory/morphing hydrogel with tunable and reversible bending and folding capabilities.
• The protein folding-unfolding mechanism is effectively leveraged for programmable shape morphing.
• This work offers new inspiration for designing and fabricating advanced protein-based morphing materials.