How cells tiptoe on adhesive surfaces before sticking

Area of Science:

• Cell Biology
• Biophysics
• Materials Science

Background:

• Cell membranes possess protrusions, but their 3D dynamics during surface interaction are unclear.
• Understanding cell membrane motion is key to explaining cell adhesion and response to topography.

Purpose of the Study:

• To investigate the dynamics of cell membrane deformations during initial contact with fibronectin-coated surfaces.
• To elucidate the role of membrane undulations in cell adhesion and surface topography sensing.

Main Methods:

• Utilized advanced microscopy techniques to observe monocytic cells interacting with fibronectin substrates.
• Analyzed nanometer-scale motions and deformations of the cell membrane in real-time.

Main Results:

• Observed membrane undulations with 5 nm amplitude and 5-10 s lifetime.
• Cells detected surfaces at 50 nm, leading to amplified undulations.
• Contact maturation involved molecule egress and sustained membrane fluctuations.

Conclusions:

• Cell membrane undulations are critical for sensing substrate topography and initiating cell adhesion.
• These dynamics influence the outcome and kinetics of cell-surface interactions.
• Membrane undulations may govern initial contact extension and cell sensitivity to surface features.