Nanoscale, Voltage-Driven Application of Bioactive Substances onto Cells with Organized Topography
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
With scanning ion conductance microscopy (SICM), a noncontact scanning probe technique, it is possible both to
obtain information about the surface topography of live cells and to apply molecules onto specific nanoscale structures. The
technique is therefore widely used to apply chemical compounds and to study the properties of molecules on the surfaces of
various cell types. The heart muscle cells, i.e., the cardiomyocytes, possess a highly elaborate, unique surface topography
including transverse-tubule (T-tubule) openings leading into a cell internal system that exclusively harbors many proteins necessary
for the cell’s physiological function. Here, we applied isoproterenol into these surface openings by changing the applied
voltage over the SICM nanopipette. To determine the grade of precision of our application we used finite-element simulations
to investigate how the concentration profile varies over the cell surface. We first obtained topography scans of the cardiomyocytes
using SICM and then determined the electrophoretic mobility of isoproterenol in a high ion solution to be 7 10 9 m2
/V s.
The simulations showed that the delivery to the T-tubule opening is highly confined to the underlying Z-groove, and especially to
the first T-tubule opening, where the concentration is ~6.5 times higher compared to on a flat surface under the same delivery
settings. Delivery to the crest, instead of the T-tubule opening, resulted in a much lower concentration, emphasizing the importance
of topography in agonist delivery. In conclusion, SICM, unlike other techniques, can reliably deliver precise quantities of
compounds to the T-tubules of cardiomyocytes
obtain information about the surface topography of live cells and to apply molecules onto specific nanoscale structures. The
technique is therefore widely used to apply chemical compounds and to study the properties of molecules on the surfaces of
various cell types. The heart muscle cells, i.e., the cardiomyocytes, possess a highly elaborate, unique surface topography
including transverse-tubule (T-tubule) openings leading into a cell internal system that exclusively harbors many proteins necessary
for the cell’s physiological function. Here, we applied isoproterenol into these surface openings by changing the applied
voltage over the SICM nanopipette. To determine the grade of precision of our application we used finite-element simulations
to investigate how the concentration profile varies over the cell surface. We first obtained topography scans of the cardiomyocytes
using SICM and then determined the electrophoretic mobility of isoproterenol in a high ion solution to be 7 10 9 m2
/V s.
The simulations showed that the delivery to the T-tubule opening is highly confined to the underlying Z-groove, and especially to
the first T-tubule opening, where the concentration is ~6.5 times higher compared to on a flat surface under the same delivery
settings. Delivery to the crest, instead of the T-tubule opening, resulted in a much lower concentration, emphasizing the importance
of topography in agonist delivery. In conclusion, SICM, unlike other techniques, can reliably deliver precise quantities of
compounds to the T-tubules of cardiomyocytes
Date Issued
2016-01-05
Date Acceptance
2015-11-11
Citation
Biophysical Journal, 2016, 110 (1), pp.141-146
ISSN
1542-0086
Publisher
Biophysical Society
Start Page
141
End Page
146
Journal / Book Title
Biophysical Journal
Volume
110
Issue
1
Copyright Statement
© 2016 The Authors. This is an open access article under the CC BY-NC-ND license (http://
creativecommons.org/licenses/by-nc-nd/4.0/).
creativecommons.org/licenses/by-nc-nd/4.0/).
Subjects
Science & Technology
Life Sciences & Biomedicine
Biophysics
ION CONDUCTANCE MICROSCOPY
LIVING CELLS
CARDIOMYOCYTES
HEART
NANOPIPETTE
MOLECULES
DELIVERY
SURFACE
Publication Status
Published