Tunable photoinitiated hydrogel microspheres for quantifying cell-generated forces in complex three-dimensional...

Area of Science:

• Cell Biology
• Biophysics
• Materials Science

Background:

• Quantifying mechanical forces in cell biology is vital but challenging in native environments.
• Hydrogel microspheres are promising for force measurement but face production limitations.
• Existing methods struggle with high-yield, tunable, and monodisperse probe fabrication.

Purpose of the Study:

• To develop a high-throughput microfluidic method for producing cellular force microscopy probes.
• To create probes with controlled size, elastic modulus, and tunable properties.
• To enable accurate measurement of cellular forces in physiologically relevant systems.

Main Methods:

• Utilized flow-focusing microfluidics for reproducible droplet generation.
• Employed acrylamide precursor and LAP photoinitiator for controlled polymerization.
• Functionalized microspheres with ECM proteins and embedded fluorescent nanobeads for tracking.

Main Results:

• Generated large quantities of monodisperse polyacrylamide (PAAm) hydrogel microspheres.
• Successfully functionalized probes and embedded tracking nanobeads.
• Measured 3D traction forces exerted by vascular endothelial cells on probes.

Conclusions:

• The microfluidic method overcomes barriers in PAAm microsphere fabrication.
• The developed probes offer tunable stiffness and monodisperse size.
• This technique provides a powerful tool for studying cellular mechanobiology and forces in complex systems.