STED Nanoscopy of Interfaces and Interactions between Nanostructure Arrays and Living Cells

Research output: Contribution to conferenceAbstract

Abstract

STED Nanoscopy of Interfaces and Interactions between Nanostructure Arrays and Living Cells The specific arrangement of membrane lipids and proteins in a living cell at the interface to high-aspect ratio nanostructures (nanowires and nanostraws) is still unknown – as are the dynamic structural adaptations and molecular rearrangements of living cells in the vicinity of such nanostructures. Whether the nanostructures actually pierce through the cell membrane or how introduced changes in membrane curvature change the biophysical properties of the cell membrane is of particular interest for investigations of the efficacy and safety of nano-sized tissue implants and for studying the delivery of substances into living cells via hollow nanostraws. To elucidate these questions, STimulated Emission Depletion (STED) nanoscopy is the ideal technique because it is live-cell compatible, target-specific, and offers a lateral resolution on the protein level (<30 nm). Here we present STED based investigations of the live-cell membrane and the cytoskeletal Actin signal in the presence of hollow Alumina nanostraws with diameter of 100 nm. As cellular model system we chose the lung-cancer derived A549 culture cell line. The cells were incubated on the nanostraws and subsequently fluorescence-tagged with live-cell compatible labels targeting the cell membrane and filamentous Actin, respectively. We find that the cellular membrane forms ring structures of about 100 nm in diameter, wrapping tightly around the nanostraws. On the other hand, the Actin cytoskeleton forms intricate, coil-like nanometric structures around the nanostraws; these structures strongly vary in diameters between 250-600 nm and appear to widen with increasing distance from the nanostraw substrate. In addition, STED images of living cells stained for both membrane and Actin signal reveal a significant degree of co-localization at the apical cell membrane, i.e. further away from the nanostraws. This co-localization is almost entirely lost at the basal membrane close to the nanostraws which is due to a strongly reduced Actin signal on that side of the cell. In conclusion, our sub-diffraction STED imaging based investigations of the behavior of single living cells cultured on nanostraws reveals a strong response of the cellular membrane and the Actin cytoskeleton – two of the main structure-giving features of the cell. In a next step, we will extend our studies to additional scaffolding proteins to arrive at a more detailed map of the topology of living cells at the interface to nanostructures of different geometries.

Details

Authors
Organisations
Original languageEnglish
Number of pages1
Publication statusPublished - 2018 Nov 25
Publication categoryResearch
Peer-reviewedNo
Eventmrs fall meeting 2018 - Boston, Boston, United States
Duration: 2018 Nov 252018 Nov 30

Conference

Conferencemrs fall meeting 2018
CountryUnited States
CityBoston
Period2018/11/252018/11/30