Interparticle Crosslinked Ion-Responsive Microgels for 3D and 4D (Bio)Printing Applications

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Biofabrication

Background:

• Microgels offer advantages over bulk hydrogels, particularly stimuli-responsive variants with bioactive and self-supporting characteristics.
• Existing biomaterials often require filler hydrogels, hindering cell migration and vascularization within constructs.

Purpose of the Study:

• To develop interparticle-crosslinked, self-supporting, ion-responsive microgels for 3D and 4D bioprinting.
• To create microgels that eliminate the need for filler hydrogels, preserving void spaces for cell infiltration and vascularization.
• To achieve tunable, reversible ion-responsive shrinking behavior via the Hofmeister effect.

Main Methods:

• Fabrication of interparticle-crosslinked, ion-responsive microgels.
• Validation of microgel properties including shear-thinning, self-healing, and print fidelity.
• Application of various bioprinting techniques (extrusion-based, embedded, intraembedded, aspiration-assisted).
• Development of multi-material 4D printing using ion-responsive and non-responsive microgels.

Main Results:

• Constructs supported angiogenesis with tunable vessel sizes.
• Demonstrated excellent shear-thinning, self-healing properties, and high print fidelity.
• Achieved multi-material 4D printing with programmable shape transformations (coiling filaments, grippers, folding sheets).

Conclusions:

• Developed novel ion-responsive microgels for advanced bioprinting applications.
• Demonstrated the potential of these microgels for creating complex, dynamic structures for tissue engineering and soft robotics.
• Highlighted the significance of interparticle crosslinking and ion-responsiveness for enhanced biomaterial design.