Cation-crosslinkedκ-carrageenan sub-microgel medium for high-quality embedded bioprinting

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Bioprinting Technology

Background:

• Embedded 3D bioprinting is promising for biomimetic scaffolds but faces challenges with microgel particle size, polydispersity, and cytocompatibility.
• Existing microgel media limit the resolution and fidelity of tissue-scale structure fabrication.

Purpose of the Study:

• To develop uniform, cell-friendly sub-microgels for high-resolution embedded 3D bioprinting.
• To overcome limitations of traditional microgel baths in fabricating intricate tissue architectures.

Main Methods:

• A mechanical grinding strategy was used to create uniform sub-microgels of cationic-crosslinked kappa-carrageenan (κ-Car).
• Characterization of sub-microgel size, jamming-unjamming transition, shear-thinning, and self-healing properties.
• Fabrication of various 3D tissue and organ structures using the κ-Car sub-microgel medium.

Main Results:

• Uniform κ-Car sub-microgels (approx. 642 nm) with rapid jamming-unjamming transitions (within 5 s) were successfully produced.
• Excellent shear-thinning and self-healing properties were achieved, crucial for high-resolution bioprinting.
• Intricate 3D constructs of heart, lungs, trachea, vasculature, kidney, auricle, nose, and liver were fabricated with high fidelity.
• Encapsulated bone marrow mesenchymal stem cells showed >92.1% viability and robust growth.

Conclusions:

• The developed κ-Car sub-microgel medium enables high-quality embedded 3D bioprinting.
• This innovation facilitates the fabrication of functional biological constructs with biomimetic organization.
• Offers a new pathway for advancing tissue engineering and regenerative medicine.