to individual cells and is highly inefficient at targeting the desired
cells. Physical methods rely on forces to penetrate the membrane.
Among all physical delivery methods, microinjection [4] is the most
straightforward approach that can deliver cargo into the cytosol
using a fine pipette to pierce through the cell membrane. However,
its manual operation greatly decreases the practical efficiency and
user-friendliness, thereby limiting the applications [9].
Compared to other physical counterparts, electroporation
achieves higher transfection efficiency with ease by optimizing the
electric field on the cells. When a charge is applied across the cells, it
permeabilizes the membrane temporarily [8]. In commercial electroporation systems, cells are placed in buffer solution in a chamber
between parallel plates, and a charge is applied across the plates.
The cell membranes will open, accepting drugs or particles within
the suspended solution through diffusion [10]. Commercial electroporation typically causes serious cell damage due to the high
voltage electric field in the bulk environment [11, 12]. Moreover, it
is impossible to control the transfection at the single cell
resolution [13].
To precisely electroporate single cells, a 3D nanoelectroporation (NEP) device was designed, as shown in Fig. 1 [12]. A 3D
nanochannel array is fabricated on the nanochip, labeled as 3D
NEP chip. A z-directional electric field is applied over each single
cell aligned on a nanochannel. The nanochannel accurately focus
the electric field on the cell membrane for safe electroporation
Fig. 1 The cross-sectional schematic of 3D NEP. The system consists of a nanochannel array chip, a support
platform, two PDMS spacers, and a bottom of electrode, all of which confined a top chamber where cells are
load and a bottom chamber filled with cargo. An electric field (black arrow) is generated by a voltage pulses
applied between a top planar electrode and the bottom electrode, by which the cargo is delivered through the
nanochannel and are injected into the cells aligned on the nanochannel array. Reproduced with permission
from RSC
30
Lingqian Chang et al.
cells. Physical methods rely on forces to penetrate the membrane.
Among all physical delivery methods, microinjection [4] is the most
straightforward approach that can deliver cargo into the cytosol
using a fine pipette to pierce through the cell membrane. However,
its manual operation greatly decreases the practical efficiency and
user-friendliness, thereby limiting the applications [9].
Compared to other physical counterparts, electroporation
achieves higher transfection efficiency with ease by optimizing the
electric field on the cells. When a charge is applied across the cells, it
permeabilizes the membrane temporarily [8]. In commercial electroporation systems, cells are placed in buffer solution in a chamber
between parallel plates, and a charge is applied across the plates.
The cell membranes will open, accepting drugs or particles within
the suspended solution through diffusion [10]. Commercial electroporation typically causes serious cell damage due to the high
voltage electric field in the bulk environment [11, 12]. Moreover, it
is impossible to control the transfection at the single cell
resolution [13].
To precisely electroporate single cells, a 3D nanoelectroporation (NEP) device was designed, as shown in Fig. 1 [12]. A 3D
nanochannel array is fabricated on the nanochip, labeled as 3D
NEP chip. A z-directional electric field is applied over each single
cell aligned on a nanochannel. The nanochannel accurately focus
the electric field on the cell membrane for safe electroporation
Fig. 1 The cross-sectional schematic of 3D NEP. The system consists of a nanochannel array chip, a support
platform, two PDMS spacers, and a bottom of electrode, all of which confined a top chamber where cells are
load and a bottom chamber filled with cargo. An electric field (black arrow) is generated by a voltage pulses
applied between a top planar electrode and the bottom electrode, by which the cargo is delivered through the
nanochannel and are injected into the cells aligned on the nanochannel array. Reproduced with permission
from RSC
30
Lingqian Chang et al.