Expansion Microscopy for Imaging the Cell-Material Interface

Area of Science:

• Biomaterials Science
• Cell Biology
• Microscopy

Background:

• Surface nanotopography significantly influences cell behavior, including adhesion, migration, and differentiation.
• Existing super-resolution microscopy techniques for studying cell-material interfaces are often complex, expensive, and inaccessible.
• Expansion microscopy (ExM) offers an affordable way to image beyond the diffraction limit but is challenging to apply to non-expanding materials like those at the cell-material interface.

Purpose of the Study:

• To develop a novel protocol enabling Expansion Microscopy (ExM) for high-resolution imaging of the cell-material interface.
• To investigate the spatial organization of cellular components at the nanoscale interface with nanostructured substrates.
• To visualize the interaction of osteoblasts with titanium dental implants for insights into osseointegration.

Main Methods:

• Development of a modified ExM protocol compatible with non-expanding materials at the cell-material interface.
• Application of the ExM protocol to image U2OS cells on nanostructured substrates.
• Application of the ExM protocol to image primary osteoblasts interacting with titanium dental implants.

Main Results:

• The ExM protocol successfully resolved the cell-material interface with high spatial resolution.
• ExM revealed the spatial segregation of AP2 and F-actin at curved membranes induced by vertical nanostructures.
• The technique enabled reliable imaging of osteoblast interactions with roughened titanium implant surfaces, overcoming previous technical limitations.

Conclusions:

• The developed ExM protocol is a powerful and accessible tool for studying the cell-material interface at the nanoscale.
• This method provides new insights into how cells interact with nanotopographical features and implant surfaces.
• The findings have significant implications for understanding cell behavior on biomaterials and improving dental implant osseointegration.