Phototunable Viscoelasticity in Hydrogels Through Thioester Exchange

Area of Science:

• Biomaterials Science
• Cell Biology
• Mechanobiology

Background:

• The extracellular matrix provides mechanical cues crucial for cell functions like development and differentiation.
• Understanding how cells perceive and respond to different mechanical properties (elastic vs. viscoelastic) is an ongoing research area.

Purpose of the Study:

• To develop a synthetic cell culture substrate with tunable viscoelastic properties.
• To investigate how NIH 3T3 fibroblasts respond to changes in substrate viscoelasticity over time.

Main Methods:

• Fabrication of thioester hydrogels using click chemistry, allowing in situ modulation of viscoelasticity via a photoinitiated thiol-ene reaction.
• Switching off substrate viscoelasticity without altering the elastic modulus.
• Culturing NIH 3T3 fibroblasts on elastic and viscoelastic substrates and monitoring cell area and YAP/TAZ localization.

Main Results:

• Fibroblasts cultured on viscoelastic substrates showed larger cell areas and higher nuclear-to-cytoplasmic YAP/TAZ ratios compared to those on elastic substrates.
• Switching off viscoelasticity led to rapid cellular responses, with cell area and YAP/TAZ ratios approaching those on elastic substrates.
• The photo-tunable hydrogels allowed for precise control over mechanical cues and observation of time-dependent cellular responses.

Conclusions:

• Phototunable viscoelastic hydrogels offer a versatile platform for studying time-dependent cellular responses to mechanical stimuli.
• These findings advance the understanding of how cells interpret and react to the dynamic mechanical microenvironment.
• The system provides insights into the dynamics of mechanoresponsive cellular pathways, relevant to development and disease.