Stretchable and self-healable hyaluronate-based hydrogels for three-dimensional bioprinting

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Polymer Chemistry

Background:

• Hydrogels are crucial for 3D bioprinting but often lack mechanical strength and printability.
• Hyaluronic acid (HA)-based materials offer biocompatibility but require modification for enhanced properties.

Purpose of the Study:

• To engineer novel hyaluronate-based hydrogels with enhanced stretchability and self-healing capabilities.
• To evaluate these hydrogels as bio-inks for 3D bioprinting complex biological structures.
• To assess the viability of cells encapsulated within the 3D-printed constructs.

Main Methods:

• Synthesized oxidized hyaluronate (oHA) and hydrazide-modified hyaluronate (hHA).
• Formed double network hydrogels via chemical (acylhydrazone) and physical (charge) cross-linking.
• Incorporated adipic acid dihydrazide (ADH) to improve self-healing properties.
• Fabricated 3D constructs using the developed hydrogel bio-inks.
• Assessed mechanical properties (stretchability, self-healing) and cell viability (ATDC5 cells).

Main Results:

• oHA/hHA hydrogels exhibited excellent stretchability and flexibility due to double network formation.
• Addition of ADH significantly enhanced the self-healing capability of the hydrogels.
• 3D-printed constructs maintained structural integrity and stretchability (up to 2x original length) post-printing.
• ATDC5 cells remained viable within the 3D-bioprinted constructs in vitro.

Conclusions:

• Hyaluronic acid-based hydrogels with combined chemical and physical cross-linking offer superior mechanical properties for 3D bioprinting.
• The developed stretchable and self-healing hydrogels are suitable for fabricating complex 3D constructs with improved structural fidelity.
• This HA-based hydrogel system shows significant promise for various tissue engineering applications requiring advanced bio-inks.