Bioinspired Processing: Complex Coacervates as Versatile Inks for 3D Bioprinting

Area of Science:

• Biomedical Engineering
• Materials Science
• Biotechnology

Background:

• 3D bioprinting requires advanced biomaterials with specific physicochemical and cytocompatibility properties.
• Existing biomaterial inks face limitations in meeting these diverse requirements.
• Natural material processing inspires new approaches for biomaterial development.

Purpose of the Study:

• To develop novel, tunable biomaterial inks for 3D bioprinting using hyaluronic acid-chitosan complex coacervates.
• To investigate the potential of complex coacervates as printable bioinks with tunable mechanical properties.
• To assess the cytocompatibility and scaffold stability of 3D bioprinted constructs using these coacervate inks.

Main Methods:

• Complex coacervates were formed via associative liquid-liquid phase separation of hyaluronic acid and chitosan.
• Biomaterial ink properties were tuned by adjusting salt concentration, pH, and polymer molecular weight.
• 3D bioprinting was performed in air and aqueous solutions, followed by scaffold characterization and cytocompatibility testing.

Main Results:

• Hyaluronic acid-chitosan complex coacervates demonstrated tunable viscoelastic properties suitable for 3D bioprinting.
• The inks transitioned from viscoelastic fluids to stable solids upon printing, eliminating the need for post-processing.
• Printed scaffolds exhibited excellent cytocompatibility and long-term topological stability.
• Printability was achieved in both air and aqueous environments.

Conclusions:

• Hyaluronic acid-chitosan complex coacervates represent a new class of tunable biomaterial inks for 3D bioprinting.
• These coacervate inks offer a facile method for creating stable, cytocompatible biofabricated scaffolds.
• The developed materials significantly advance the field of biofabrication by providing easy-to-handle and versatile biomaterials.