3D Printing of Enzymatically Softening Hydrogel Biomaterials

Area of Science:

• Biomaterials Science
• Tissue Engineering
• 3D Bioprinting

Background:

• 3D printing accelerates tissue engineering but requires stiff bioinks for shape fidelity.
• Softer materials generally support better cellular function but lack structural integrity during printing.
• A gap exists in printing soft biomaterials with high resolution.

Purpose of the Study:

• To develop a hydrogel system for 3D bioprinting soft materials.
• To maintain high resolution and shape fidelity in printed constructs.
• To bridge the gap between material stiffness and cellular support.

Main Methods:

• Developed a photopolymerizable copolymer hydrogel (synthetic and natural polymers).
• Varied polymer content and ratio (poly(ethylene glycol) and gelatin) to tune stiffness.
• Utilized enzymatic treatment (collagenase) for post-print softening.

Main Results:

• Generated hydrogels with initial stiffness from 2 to 82 kPa, softening up to 20-fold.
• Softened gels exhibited higher structural integrity post-3D printing (digital light processing).
• Enhanced endothelial cell seeding and maintained high cell viability in softened gels.

Conclusions:

• The developed material system offers a solution for 3D printing soft materials with high resolution.
• Post-print softening enhances structural integrity and cellular compatibility.
• This approach expands the accessibility of soft biomaterials in tissue engineering.