Dynamic phototuning of 3D hydrogel stiffness

Area of Science:

• Biomaterials Science
• Cell Biology
• Tissue Engineering

Background:

• Hydrogels are vital for mimicking 3D cellular microenvironments in vitro.
• Extracellular matrix stiffness significantly influences cell phenotype and behavior.
• Dynamic changes in microenvironment stiffness are critical in biological processes like development and disease.

Purpose of the Study:

• To develop a hydrogel system with temporally tunable stiffness to recapitulate dynamic cellular microenvironments.
• To enable both dynamic stiffening and softening of hydrogels for advanced biological studies.
• To investigate the role of dynamic stiffness modulation on fibroblast morphology and migration.

Main Methods:

• Utilized alginate hydrogels with light-triggered release of calcium or chelators from liposomes for stiffness modulation.
• Demonstrated temporal stiffness modulation at least 14 days post-gelation.
• Employed near-infrared light for in vivo transdermal stiffness control.

Main Results:

• Achieved dynamic stiffening and softening of hydrogels, surpassing previous methods.
• Showcased spatial control over stiffness, enabling gradient and pattern formation.
• Observed that stiffening inhibits fibroblast spreading via both mesenchymal and amoeboid migration.

Conclusions:

• The developed hydrogel system offers unprecedented temporal and spatial control over matrix stiffness.
• This technology provides a powerful tool for investigating the impact of dynamic microenvironments in vitro and in vivo.
• Enables new avenues for understanding cell behavior in complex, changing biological settings.