Peptide-Crosslinked, Highly Entangled Hydrogels with Excellent Mechanical Properties but Ultra-Low Solid Content

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomaterials Engineering

Background:

• Ordinary hydrogels suffer from brittleness and weakness due to low solid content.
• Developing hydrogels with both low solid content and robust mechanical properties remains a significant challenge.

Purpose of the Study:

• To synthesize hydrogels with ultra-low solid content that exhibit enhanced mechanical properties.
• To investigate the role of peptide cross-linkers in improving hydrogel performance.

Main Methods:

• Synthesized hydrogels using high monomer concentrations and low cross-linker/monomer ratios.
• Employed poly(l-lysine)-based peptide cross-linkers.
• Compared properties with hydrogels cross-linked using N,N'-methylenebisacrylamide (BIS).

Main Results:

• Achieved ultra-low solid content (5.8%) in peptide-crosslinked hydrogels with high swelling.
• Demonstrated excellent mechanical properties: 440% stretchability, 220 KPa tensile strength, 99% resilience, 2100 J m⁻² fracture toughness.
• Exhibited superior fatigue resistance, low friction, and high wear resistance compared to BIS-crosslinked hydrogels.

Conclusions:

• Peptide cross-linking enables the creation of highly entangled hydrogel structures with exceptional mechanical strength at ultra-low solid content.
• The breakage of intramolecular hydrogen bonds within the peptide helical structure provides a novel energy dissipation mechanism, enhancing material resilience and toughness.