Photodegradable Polyacrylamide Gels for Dynamic Control of Cell Functions

Area of Science:

• Biomaterials Science
• Cell Biology
• Biotechnology

Background:

• Polyacrylamide hydrogels offer tunable stiffness and ligand attachment for cell culture.
• Current hydrogels have fixed properties after fabrication, limiting dynamic studies.
• Dynamic control over material properties is crucial for understanding cell mechanobiology.

Purpose of the Study:

• To develop a light-controllable photodegradable polyacrylamide hydrogel system.
• To investigate the impact of dynamic stiffness changes on cell behavior.
• To explore how *in situ* substrate softening influences cellular responses.

Main Methods:

• Synthesized photodegradable hydrogels via copolymerization of acrylamide and *ortho*-nitrobenzyl (o-NB) bis-acrylate.
• Utilized light exposure to induce photocleavage of o-NB cross-links, reducing gel stiffness.
• Cultured cells on gels with dynamic stiffness changes and analyzed YAP nuclear localization and cytoskeletal organization.

Main Results:

• Demonstrated light-induced decrease in polyacrylamide hydrogel stiffness.
• Showcased that *in situ* hydrogel softening alters cell behavior differently than pre-softened gels.
• Observed significant changes in YAP localization and cytoskeleton organization upon *in situ* softening, dependent on surface protein conditions.

Conclusions:

• Developed a novel photodegradable polyacrylamide hydrogel system for dynamic stiffness control.
• Highlighted the importance of dynamic mechanical cues in influencing cell fate and behavior.
• Enabled advanced studies of cell mechanobiology previously limited by static hydrogel properties.