Characterization of a Novel Light Source for Simultaneous Optical and Scanning Ion Conductance Microscopy

The functionality of living cells is inherently linked to subunits with dimensions ranging from several micrometers down to the nanometer scale. The cell surface plays a particularly important role. Electric signaling, including information processing, takes place at the membrane, as well as adhesion and contact. For osteoblasts, adhesion and spreading are crucial processes with regard to bone implants. Here we present a comprehensive characterization of the 3D nanomorphology of living, as well as fixed, osteoblastic cells using scanning ion conductance microscopy (SICM), which is a nanoprobing method that largely avoids mechanical perturbations. Dynamic ruffles are observed, manifesting themselves in characteristic membrane protrusions. They contribute to the overall surface corrugation, which we systematically study by introducing the relative 3D excess area as a function of the projected adhesion area. A clear anticorrelation between the two parameters is found upon analysis of ca. 40 different cells on glass and on amine-covered surfaces. At the rim of lamellipodia, characteristic edge heights between 100 and 300 nm are observed. Power spectral densities of membrane fluctuations show frequency-dependent decay exponents with absolute values greater than 2 on living osteoblasts. We discuss the capability of apical membrane features and fluctuation dynamics in aiding the assessment of adhesion and migration properties on a single-cell basis.

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BIOPHYSICAL APPLICATIONS OF SCANNING ION CONDUCTANCE MICROSCOPY (SICM)

Modern Physics Letters B ◽

10.1142/s0217984911300031 ◽

2012 ◽

Vol 26 (05) ◽

pp. 1130003 ◽

Cited By ~ 16

Author(s):

FRANKLIN ANARIBA ◽

JOON HYUNG ANH ◽

GOO-EUN JUNG ◽

NAM-JOON CHO ◽

SANG-JOON CHO

Keyword(s):

Chemical Properties ◽

Live Cells ◽

Cell Dynamics ◽

Fundamental Physics ◽

Ion Conductance ◽

Scanning Ion Conductance Microscopy ◽

Patch Clamp Electrophysiology ◽

And Function ◽

Physical And Chemical

Scanning probe microscopy (SPM) techniques represent one of the most promising approaches to probe the physical and chemical properties of nanoscale materials. The growing convergence of physics and biology has demanded nanotechnology tools to understand the fundamental physics of biological systems. Despite the advantages of SPM techniques, there have been challenges with its application to characterization of biological specimens. In recent times, the development of one class of SPM technique, scanning ion conductance microscopy (SICM), has overcome these limitations and enabled noninvasive, nanoscale investigation of live cells. In this review article, we present the theory behind the SICM operating principles and data modeling. Based on this framework, we discuss recent research advances where the SICM technique has proven technically superior. SICM applications discussed herein include imaging of cell topography, monitoring of live cell dynamics, mechanical stimulation of live cells, and surface patterning. Additional findings on the combination of SICM with other SPM techniques as well as patch clamp electrophysiology are presented in the context of building integrated knowledge on the structure and function of live cells. In summary, SICM bridges physics and biology to enable a range of important biomedical applications.

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