Adhesive Hydrogel Building Blocks to Reconstruct Complex Cartilage Tissues.

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Cartilage exhibits limited self-healing, necessitating surgical repair.
• Existing cartilage replacement methods face limitations, driving demand for synthetic substitutes.
• Native cartilage possesses high hydration, mechanical strength, and regional stiffness variations.

Purpose of the Study:

• To develop novel cartilage-mimetic substitutes.
• To engineer triple network (TN) hydrogels with cartilage-like properties.
• To achieve robust inter-material adhesion for construct fabrication.

Main Methods:

• Preparation of triple network (TN) hydrogels with tunable hydration and moduli.
• Incorporation of anionic or cationic third networks to induce electrostatic adhesion.
• Characterization of hydrogel shear strength and adhesive properties.
• Demonstration of TN hydrogel utility in fabricating a zonal intervertebral disc construct.

Main Results:

• TN hydrogels achieved cartilage-like hydration (60-80%) and moduli (≥1 MPa).
• Adhesion was achieved via electrostatic interactions between oppositely charged third networks.
• Increased third network concentration yielded robust shear strengths (∼80 kPa).
• TN hydrogels successfully formed a zonal intervertebral disc construct.

Conclusions:

• Adhesive TN hydrogels show promise as cartilage substitutes.
• These materials can recapitulate native cartilage's regional mechanical properties.
• TN hydrogels offer a viable strategy for creating advanced cartilage-mimetic constructs.