Probed adhesion force of living lung cells with a tip-modified atomic force microscope

Area of Science:

• Biophysics
• Materials Science
• Cell Biology

Background:

• Extracellular matrix mechanical properties influence cellular microenvironments.
• Understanding cell-surface interactions is crucial for bio-microenvironment research.

Purpose of the Study:

• To measure the adhesion forces between gold (Au) and silver (Ag) nanoparticle (NP) clusters and human fetal lung cells using atomic force microscopy (AFM).
• To analyze how NP cluster size, dimension, and material affect cell-surface interactions.

Main Methods:

• Utilized AFM to probe adhesion forces between modified AFM tips and lung cells.
• Grafted Au and Ag NP clusters onto AFM tips using (3-mercapto-propyl) triethoxysilane (MPTMS).
• Analyzed force-distance curves to quantify adhesion forces.

Main Results:

• MPTMS modification increased adhesion force from 92 pN to 332 pN due to non-specific interactions.
• Au NP clusters on AFM tips showed adhesion forces of 122 pN, increasing with cluster size.
• Ag NP clusters on AFM tips reduced adhesion force to 56 pN.
• Adhesion forces varied based on NP material, size, and surface properties.

Conclusions:

• Nanoparticle clusters significantly modify adhesion forces between AFM tips and lung cells.
• Results suggest electrostatic and van der Waals forces play a role in NP-cell interactions.
• Findings provide insights into nanoparticle-surface interactions relevant to lung cell membranes.