Bioprinting dynamic hydrazone hydrogels via light-mediated crosslinking

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Polymer Chemistry

Background:

• Viscoelastic hydrogels with dynamic bonds are crucial for mimicking native tissue matrix dynamics.
• Current limitations exist in applying these dynamic hydrogels to light-based bioprinting due to photocrosslinking incompatibility.
• This study addresses the challenge of integrating reversible bond formation with photocrosslinking in bioinks.

Purpose of the Study:

• To develop a novel class of photocrosslinkable, hydrazone-based bioinks.
• To enable reversible bond formation within hydrogel networks for dynamic tissue mimicry.
• To investigate the tunability of bioink properties and their impact on cell morphology.

Main Methods:

• Synthesized two modified polymers (Gel-A-DAAM and Gel-C-DAAM) with polymerizable groups via hydrazone conjugation chemistry.
• Fabricated hydrogels using droplet-based bioprinting followed by light-based crosslinking.
• Characterized hydrogel mechanical properties (storage moduli 0.08-1.2 kPa) and evaluated human fibroblast cell spreading and morphology.

Main Results:

• Developed hydrazone-based bioinks that are photocrosslinkable and exhibit reversible bond formation.
• Achieved tunable mechanical properties (0.08-1.2 kPa storage moduli) suitable for various physiological tissue environments.
• Demonstrated successful bioprinting and cell spreading, with cell morphology varying based on hydrazide substituents, indicating potential for cell-matrix interaction studies.

Conclusions:

• The novel bioink system offers a promising platform for creating next-generation tissue-mimetic constructs.
• The combination of biological tunability and printability facilitates advanced bioprinting technologies.
• This system provides a unique tool to systematically investigate cell-matrix interactions in engineered tissues.