Can single molecule localization microscopy be used to map closely spaced RGD nanodomains?

Area of Science:

• Biophysics
• Materials Science
• Cell Biology

Background:

• Cells respond to nanoscale variations in ligand distribution on adhesion receptors.
• Single molecule localization microscopy (SMLM) is suitable for mapping ligands on nanopatterned surfaces.

Purpose of the Study:

• To investigate SMLM spatial cluster analysis for detecting nanodomains of arginine-glycine-aspartic acid (RGD) peptides.
• To evaluate the influence of nanodomain spacing and localization precision on detection accuracy.

Main Methods:

• Atomic force microscopy (AFM) to determine block copolymer topology.
• Direct stochastic optical reconstruction microscopy (dSTORM) to image individual RGD peptide localization.
• DBSCAN for spatial cluster analysis of dSTORM data.
• Simulations to assess nanodomain mapping with dSTORM.

Main Results:

• dSTORM successfully mapped RGD nanodomains formed by block copolymer phase separation.
• Nanodomain detection accuracy depended on inter-domain spacing and localization precision.
• Accurate mapping of nanodomains closer than 50 nm required ~11 nm localization precision.
• Non-specific ligand absorption had minimal impact on nanodomain detection.

Conclusions:

• SMLM is a promising technique for mapping nanoscale ligand distribution and organization.
• Improved localization precision in SMLM is beneficial for detailed nanoscale mapping.
• Understanding ligand distribution is key for deciphering cell-nanomaterial interactions.