Nonlinear Nanoscale Electrical Transport Distinguishes Fibroblasts and Osteoblasts

Area of Science:

• Biophysics
• Cell Biology
• Nanotechnology

Background:

• Electrical signaling is crucial for cellular functions.
• Existing methods for mapping cellular electrical activity lack nanoscale resolution or perturb cells.

Purpose of the Study:

• To develop and apply conductive atomic force microscopy (CAFM) for nanoscale electrical transport mapping within cells.
• To investigate subcellular electrical heterogeneity and its relation to cell phenotype.

Main Methods:

• Utilized conductive atomic force microscopy (CAFM) to measure local current-voltage (I-V) characteristics.
• Examined fixed and air-dried L929 fibroblasts and OFCOLII osteoblasts on indium tin oxide (ITO) substrates.

Main Results:

• Observed enhanced electrical response in nuclear regions compared to cytoplasmic areas in both cell types.
• L929 fibroblasts showed linear, ohmic-like electrical transport, while OFCOLII osteoblasts exhibited nonlinear, diode-like transport.
• Identified significant cell-type and region-dependent variations in effective resistance and capacitance.

Conclusions:

• CAFM effectively resolves subcellular electrical heterogeneity.
• Distinct electrical transport signatures can differentiate cellular phenotypes at the single-cell level.
• Nanoscale electrical transport serves as a physically grounded marker of cellular phenotype.