Dynamic Gelatin Hydrogels Crosslinked by Dithiolane-Norbornene Click Chemistry

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Stem Cell Biology

Background:

• Gelatin hydrogels mimic the extracellular matrix (ECM) but lack thermal stability for 3D cell culture.
• Modified gelatins like Gelatin-methacryloyl (GelMA) and Gelatin-norbornene (GelNB) enable stable photopolymerization.
• Existing gelatin hydrogels often lack dynamically tunable properties.

Purpose of the Study:

• To develop dynamically tunable and cytocompatible gelatin-based hydrogels.
• To enable in situ manipulation of hydrogel properties for advanced cell culture applications.
• To create a platform for human induced pluripotent stem cell (hiPSC) encapsulation, culture, and differentiation.

Main Methods:

• Integration of GelNB with a dithiolane-containing crosslinker, poly(ethylene glycol)-tetra-lipoic acid (PEG4LA).
• Modular photo-crosslinking of GelNB/PEG4LA hydrogels under cytocompatible light conditions (365 nm, 5 mW/cm², 1 mM LAP).
• Dynamic tuning of hydrogel stiffness via secondary light-induced dithiolane ring-opening.

Main Results:

• Successful formation of stable GelNB/PEG4LA hydrogels under mild photopolymerization conditions.
• Demonstrated dynamic tunability of hydrogel stiffness through secondary light exposure.
• Validated cytocompatibility and suitability for hiPSC encapsulation, culture, and differentiation.

Conclusions:

• GelNB/PEG4LA hydrogels offer a tunable and cytocompatible platform for 3D cell culture.
• The developed hydrogels are suitable for advanced applications including stem cell manipulation.
• This work advances the development of smart biomaterials for regenerative medicine.