Ultrahigh-Water-Content yet Robust Hydrogels Enabled by Bioinspired Laminated Membranous Network

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Materials Engineering

Background:

• Hydrogels are water-rich polymer networks crucial for structural biomaterials.
• Typically, higher water content in hydrogels leads to reduced mechanical robustness (softness, low fracture stress).
• Jellyfish mesoglea uniquely combines high stiffness, strength, and ultrahigh water content.

Purpose of the Study:

• To investigate the structural basis for jellyfish mesoglea's exceptional mechanical properties.
• To develop a fabrication method for creating hydrogels with similar properties.
• To overcome the conventional trade-off between hydrogel mechanical robustness and water content.

Main Methods:

• Analysis of jellyfish mesoglea's long-range-ordered laminated membranous network structure.
• Fabrication of chitosan hydrogels using evaporation-induced phase separation.
• Alignment and crystallization of membranes via in-plane stretching and sodium hydroxide treatment.

Main Results:

• Jellyfish mesoglea's structure features crystal orientation and collagen spanning, enhancing stress resistance and dispersion.
• Fabricated chitosan hydrogels mimic this network structure.
• The resulting hydrogels achieve high modulus (5.2 MPa) and strength (6.5 MPa) with 91.8 wt.% water content.

Conclusions:

• A laminated membranous network structure is key to achieving robust hydrogels with high water content.
• The demonstrated fabrication method provides a viable approach for creating advanced hydrogels.
• This work offers a new structural concept for designing hydrogels that surpass existing synthetic and biological materials.