Three-Dimensional Printable Hydrogel Using a Hyaluronic Acid/Sodium Alginate Bio-Ink

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Three-dimensional (3D) bioprinting requires advanced bio-inks with specific properties for successful tissue engineering.
• Hyaluronic acid (HA) and sodium alginate (SA) are biocompatible polymers with potential for bio-ink development.

Purpose of the Study:

• To synthesize and characterize a novel bio-ink composed of hyaluronic acid (HA) and sodium alginate (SA) for 3D bioprinting.
• To evaluate the viscosity, printability, and structural integrity of the developed bio-ink.
• To assess the biocompatibility and cell proliferation within the bio-ink for tissue engineering applications.

Main Methods:

• Synthesis of HA/SA blended hydrogels with varying HA concentrations (0-30% w/v) without chemical crosslinking agents for HA.
• Rheological characterization to determine viscosity at a shear rate of 0.1 s⁻¹.
• 3D printing evaluation of viscosity, printability, and structural integrity post-crosslinking with CaCl₂.
• Biocompatibility assessment using live/dead assays and WST-1 proliferation assay with NIH3T3 fibroblast cells.

Main Results:

• Successfully printed HA/SA blended hydrogels with increasing viscosity correlating to higher HA content (883-1525 Pa·s at 0.1 s⁻¹).
• The printed hydrogel structures showed no significant shrinkage after CaCl₂ crosslinking and maintained integrity during culture.
• Encapsulated NIH3T3 fibroblast cells exhibited a 70% higher relative proliferation rate in HA/SA bio-ink compared to SA-only bio-ink after four days.

Conclusions:

• The developed HA/SA blended hydrogel is a promising 3D printable bio-ink for tissue engineering.
• The formulation offers tunable viscosity and excellent biocompatibility, supporting cell proliferation.
• This novel bio-ink addresses key requirements for advanced tissue regeneration strategies.