Temperature-programmable and enzymatically solidifiable gelatin-based bioinks enable facile extrusion bioprinting.

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Polymer Chemistry

Background:

• Developing advanced bioinks for extrusion bioprinting is crucial for creating functional tissue constructs.
• Gelatin is biocompatible but lacks the viscosity and stable gelation required for high-fidelity bioprinting.
• Existing gelatin-based bioinks often compromise printability or cell viability.

Purpose of the Study:

• To engineer a modified gelatin bioink with improved printability, fidelity, and cell viability for extrusion bioprinting.
• To develop a bioink with temperature-programmable viscosity and enzyme-controlled solidification.
• To demonstrate the potential of the modified gelatin for fabricating complex, cell-laden tissue constructs.

Main Methods:

• Sequential chemical modification of gelatin with ureido-pyrimidinone (UPy) and tyramine (Tyr) moieties.
• Utilizing temperature-dependent viscosity and enzyme-triggered gelation for controlled printing and solidification.
• Fabricating various 2D and 3D cell-laden constructs, including scaffolds and tissue-like structures, using extrusion bioprinting.

Main Results:

• The modified Gel-UPy-Tyr bioink exhibited enhanced printability and superior fidelity in construct fabrication.
• Cell-laden constructs demonstrated high cell viability (>90% at 24h) and maintained cell proliferation and function over one week.
• Successful creation of diverse constructs, including 2D patterns, 3D scaffolds, and multi-cellular tissue mimics.

Conclusions:

• Chemically modified gelatin (Gel-UPy-Tyr) provides a promising platform for advanced extrusion bioprinting.
• The developed bioink overcomes the limitations of native gelatin, enabling high-fidelity fabrication of viable cell-laden constructs.
• This approach supports cell growth and function, paving the way for engineered tissues and regenerative medicine applications.