Conjoined-network rendered stiff and tough hydrogels from biogenic molecules

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Materials Engineering

Background:

• Hydrogels derived from biological sources are promising structural biomaterials.
• Existing biological hydrogels often lack sufficient stiffness and toughness.
• Conventional strategies like homogeneity improvement or double-network approaches have limitations.

Purpose of the Study:

• To develop a new strategy for creating stiff and tough hydrogels from biological sources.
• To introduce the concept of conjoined-network hydrogels as a distinct approach.
• To demonstrate the effectiveness of this strategy using a specific chitosan-gelatin-phytate system.

Main Methods:

• Development of a conjoined-network hydrogel strategy.
• Preparation of a biogenic hydrogel via electrostatic cross-linking of chitosan-gelatin with sodium phytate.
• Characterization of the hydrogel's mechanical properties, self-recovery, and fatigue resistance.

Main Results:

• The conjoined-network hydrogel achieved simultaneous high compressive modulus and toughness.
• The chitosan-gelatin-phytate system demonstrated excellent self-recovery and fatigue resistance.
• The conjoined-network structure effectively distributes stress throughout the material.

Conclusions:

• The conjoined-network approach offers a novel strategy for designing stiff and tough hydrogels.
• This method overcomes limitations of existing biological hydrogels.
• The strategy is versatile, allowing for various cross-linking mechanisms for biocompatible materials.