Quantification of nanowire penetration into living cells.
High-aspect ratio nanostructures such as nanowires and nanotubes are a powerful new tool for accessing the cell interior for delivery and sensing. Controlling and optimizing cellular access is a critical challenge for this new technology, yet even the most basic aspect of this process, whether these structures directly penetrate the cell membrane, is still unknown. Here we report the first quantification of hollow nanowires-nanostraws-that directly penetrate the membrane by observing dynamic ion delivery from each 100-nm diameter nanostraw. We discover that penetration is a rare event: 7.1±2.7% of the nanostraws penetrate the cell to provide cytosolic access for an extended period for an average of 10.7±5.8 penetrations per cell. Using time-resolved delivery, the kinetics of the first penetration event are shown to be adhesion dependent and coincident with recruitment of focal adhesion-associated proteins. These measurements provide a quantitative basis for understanding nanowire-cell interactions, and a means for rapidly assessing membrane penetration.
Department of Materials Science and Engineering, Stanford University, 476 Lomita Mall, Stanford, California 94305, USA.
Alexander M
AM
Xu
Department of Materials Science and Engineering, Stanford University, 476 Lomita Mall, Stanford, California 94305, USA.
Amin
A
Aalipour
Department of Psychiatry and Behavioral Sciences, Stanford University, 1201 Welch Road, Stanford, California 94304, USA.
Sergio
S
Leal-Ortiz
Department of Chemical Engineering, Stanford University, 381 North South Mall, Stanford, California 94305, USA.
Armen H
AH
Mekhdjian
Department of Materials Science and Engineering, Stanford University, 476 Lomita Mall, Stanford, California 94305, USA.
Xi
X
Xie
1] Department of Chemical Engineering, Stanford University, 381 North South Mall, Stanford, California 94305, USA [2] Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, California 94305, USA.
Alexander R
AR
Dunn
Department of Psychiatry and Behavioral Sciences, Stanford University, 1201 Welch Road, Stanford, California 94304, USA.
Craig C
CC
Garner
Department of Materials Science and Engineering, Stanford University, 476 Lomita Mall, Stanford, California 94305, USA.
Nicholas A
NA
Melosh
D000818:Animals; D016466:CHO Cells; D002462:Cell Membrane; D003412:Cricetulus; D003600:Cytosol; D022001:Focal Adhesions; D007700:Kinetics; D018613:Microscopy, Confocal; D043942:Nanotubes; D053770:Nanowires