Mechanically Induced Adaptive Self-Growing Protein Hydrogel.

Area of Science:

• Biomaterials Science
• Mechanochemistry
• Protein Engineering

Background:

• Living tissues exhibit adaptive growth and strengthening in response to mechanical stimuli.
• Replicating this self-reinforcing capability in synthetic materials is a significant challenge in materials science.

Purpose of the Study:

• To engineer a protein-based hydrogel capable of mechanochemically induced self-growth and reinforcement.
• To establish a generalizable framework for self-adapting biomaterials that evolve under mechanical stimulation.

Main Methods:

• Utilized the copper-storage protein Csp1 for force-regulated unfolding and Cu(I) release.
• Employed Cu(I)-catalyzed in situ azide-alkyne cycloaddition to form secondary crosslinks under mechanical load.
• Implemented a mechano-catalytic feedback loop involving Csp1 refolding and Cu(I) re-sequestration upon unloading.

Main Results:

• The protein hydrogel demonstrated autonomous self-reinforcement of mechanical properties under applied stress.
• Achieved stress- and time-dependent self-reinforcement within a closed system without external monomer supply.
• Exhibited programmable mechanical memory through cyclic growth-pause-growth transitions driven by Cu(I) homeostasis.

Conclusions:

• Developed a novel biomaterial that mimics the adaptive growth of living tissues.
• Established a generalizable mechanochemical strategy for designing self-adapting materials.
• Demonstrated the potential of protein conformational dynamics coupled with catalysis for advanced material design.