4D biofabrication via instantly generated graded hydrogel scaffolds

Area of Science:

• Biomaterials Science
• Tissue Engineering
• 4D Biofabrication

Background:

• 4D biofabrication requires shape-morphing scaffolds for complex tissue regeneration.
• Current methods for creating gradient biomaterials can be complex.

Purpose of the Study:

• To develop a facile, one-step strategy for fabricating cell-laden gradient hydrogels for 4D biofabrication.
• To demonstrate the versatility and applicability of this method in creating advanced scaffold structures.

Main Methods:

• Photocrosslinking of a mixture containing photocrosslinkable polymer, photoinitiator (PI), UV absorber, and live cells.
• Utilizing UV absorbers to control photocrosslinking and create gradients.
• Integrating the method with other hydrogel engineering techniques like 3D bioprinting.

Main Results:

• Successfully generated cell-laden gradient hydrogels with pre-programmable deformation.
• Demonstrated gradient formation in various polymers (PEG, alginate, gelatin derivatives).
• Fabricated advanced cell-laden scaffolds by integrating with microfabrication and bioprinting techniques.
• Showcased proof-of-concept 4D bone-like tissue formation.

Conclusions:

• The developed strategy offers a simple and versatile approach for creating temporal shape changes in cell-laden hydrogel scaffolds.
• This method can expedite the development of 4D biofabricated constructs for diverse biological applications.
• The technique addresses a key challenge in achieving dynamic shape changes for tissue engineering.