2 research outputs found
Interfacing Electrogenic Cells with 3D Nanoelectrodes: Position, Shape, and Size Matter
An in-depth understanding of the interface between cells and nanostructures is one of the key challenges for coupling electrically excitable cells and electronic devices. Recently, various 3D nanostructures have been introduced to stimulate and record electrical signals emanating from inside of the cell. Even though such approaches are highly sensitive and scalable, it remains an open question how cells couple to 3D structures, in particular how the engulfment-like processes of nanostructures work. Here, we present a profound study of the cell interface with two widely used nanostructure types, cylindrical pillars with and without a cap. While basic functionality was shown for these approaches before, a systematic investigation linking experimental data with membrane properties was not presented so far. The combination of electron microscopy investigations with a theoretical membrane deformation model allows us to predict the optimal shape and dimensions of 3D nanostructures for cell-chip coupling
Revealing the Cell–Material Interface with Nanometer Resolution by Focused Ion Beam/Scanning Electron Microscopy
The
interface between cells and nonbiological surfaces regulates
cell attachment, chronic tissue responses, and ultimately the success
of medical implants or biosensors. Clinical and laboratory studies
show that topological features of the surface profoundly influence
cellular responses; for example, titanium surfaces with nano- and
microtopographical structures enhance osteoblast attachment and host–implant
integration as compared to a smooth surface. To understand how cells
and tissues respond to different topographical features, it is of
critical importance to directly visualize the cell–material
interface at the relevant nanometer length scale. Here, we present
a method for <i>in situ</i> examination of the cell-to-material
interface at any desired location, based on focused ion beam milling
and scanning electron microscopy imaging to resolve the cell membrane-to-material
interface with 10 nm resolution. By examining how cell membranes interact
with topographical features such as nanoscale protrusions or invaginations,
we discovered that the cell membrane readily deforms inward and wraps
around protruding structures, but hardly deforms outward to contour
invaginating structures. This asymmetric membrane response (inward <i>vs</i> outward deformation) causes the cleft width between the
cell membrane and the nanostructure surface to vary by more than an
order of magnitude. Our results suggest that surface topology is a
crucial consideration for the development of medical implants or biosensors
whose performances are strongly influenced by the cell-to-material
interface. We anticipate that the method can be used to explore the
direct interaction of cells/tissue with medical devices such as metal
implants in the future