Cell-Friendly Indirect 3D Printing Strategy for Scaffold Fabrication.

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Bioprinting

Background:

• Hydrogel scaffolds are crucial for tissue engineering (TE) applications.
• Low-viscosity biomaterials pose challenges for extrusion-based 3D printing.
• Developing methods to fabricate cell-laden scaffolds with controlled architecture is essential.

Purpose of the Study:

• To evaluate polyvinyl alcohol (PVA) moulds for fabricating cell-containing hydrogel scaffolds using a bottom-up TE approach.
• To investigate the use of PVA moulds to overcome viscosity limitations in 3D printing of hydrogels.
• To assess the biocompatibility and mechanical properties of PVA-molded hydrogel scaffolds for soft tissue TE.

Main Methods:

• Functionalization of gelatin derivatives and assessment of their gelation behavior.
• Indirect 3D printing using water-soluble PVA moulds for low-viscosity hydrogels.
• Characterization of scaffold properties including CAD/CAM mimicry, swelling ratio, mechanical properties, and cell viability.

Main Results:

• PVA moulds exhibited excellent water solubility, biocompatibility, and photo-transmittance.
• Scaffolds demonstrated high CAD/CAM mimicry (~110%) and suitable swelling ratios (4-24) for soft TE.
• Mechanical properties (Young's moduli 0.8-2 kPa) mimicked native fatty tissue, and cell viability remained high (>80%) over 14 days.

Conclusions:

• PVA moulds effectively shape gelatin derivatives for TE applications, ensuring cell compatibility.
• This approach circumvents viscosity issues, enabling 3D printing of low-viscosity photo-crosslinkable hydrogels.
• PVA-molded hydrogel scaffolds offer control over architecture and cell behavior for advanced TE.