Aqueous Two-Phase Bioinks for Discrete Packing and Compartmentalization of 3D Bioprinted Cells.

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Aqueous two-phase systems (ATPS) offer unique microscale compartmentalization for modulating cell behavior.
• These systems are ideal for tissue engineering and regenerative medicine (TERM) applications.

Purpose of the Study:

• To develop novel ATPS biomaterial inks for 3D bioprinting of water-in-water (W/W) emulsions.
• To enable precise cellular crowding for enhanced tissue regeneration in vitro and ex vivo.

Main Methods:

• Formulation of ATPS inks using gelatin methacryloyl (GelMA) and alginic acid with varying sodium chloride (NaCl) concentrations.
• Characterization of emulsion droplet size, rheological properties, and degradation.
• Utilizing microfluidic-assisted 3D bioprinting to control fiber structure and ATPS deposition.
• Evaluating cell behavior (cytoskeletal remodeling, differentiation, crowding) and in ovo vascularization.

Main Results:

• Emulsion droplet size influenced degradation and cell localization.
• Higher salt concentrations enhanced cytoskeletal remodeling in encapsulated cells.
• Increased GelMA content promoted cell crowding, mineral deposition, and skeletal differentiation.
• Salt modulation controlled degradation and vascular infiltration in ovo.

Conclusions:

• ATPS bioinks provide a versatile platform for fabricating complex tissues with microscale precision.
• This approach expands biofabrication strategies for TERM applications.
• The developed inks allow fine-tuning of cellular microenvironments for improved tissue regeneration.