Physical Modification of Hybrid Hydrogels to Fabricate Full-Scale Construct Using Three-Dimensional Bio-Printing...

Area of Science:

• Bioprinting
• Regenerative Medicine
• Biomaterials Science

Background:

• 3D bioprinting faces challenges in geometric fidelity and mechanical complexity for customized constructs.
• Rheological properties of biomaterials are critical for printability and the final construct's geometric accuracy.

Purpose of the Study:

• To explore the rheological properties of alginate-based biomaterials enhanced with carboxymethyl cellulose (CMC) and crosslinkers (CaCl2, CaSO4).
• To investigate the impact of viscosity enhancers and crosslinkers on the printability and geometric fidelity of 3D bioprinted constructs.
• To compare the effects of pre-crosslinking and post-crosslinking strategies.

Main Methods:

• Formulations of alginate, CMC, CaCl2, and CaSO4 were prepared at varying concentrations (≤8% solid content).
• Rheological tests including flow curves, thixotropic recovery, and amplitude tests were performed.
• Geometric fidelity tests were conducted and correlated with physical properties. Large-scale constructs were fabricated to demonstrate capability.

Main Results:

• Rheological characterization revealed shear thinning behavior and gelation properties crucial for printability.
• The addition of CMC and crosslinkers significantly influenced the structural integrity and printability of the biomaterial formulations.
• Successful fabrication of cm-scale constructs demonstrated the practical application of optimized compositions.

Conclusions:

• Optimizing biomaterial composition with viscosity enhancers and crosslinkers is essential for achieving high geometric fidelity in 3D bioprinting.
• Understanding rheological behavior provides critical insights for developing advanced regenerative medicine scaffolds.
• This research offers a foundation for fabricating complex, large-scale bioprinted constructs.