apoptosis such as slow membrane recovery and harmful electrochemical reactions and indeed offer several advantages over some
commercial systems. However, most of these microscale/nanoscale
systems still ignore the local electrical variation on individual cells
among a large population (i.e., bulk electroporation or BE), leaving
many uncontrollable factors similar to what in bulk electroporation
systems. For example, the randomness of cell allocation in the
buffer solution leads to random instead of uniform permeabilization of cells.
In this study, we developed a new micropillar array electroporation (MAE) approach to tackle this problem and accomplish cell
size specific electroporation. In MAE, cells are sandwiched between
a plain plate electrode and a plate electrode composed of thousands
of micropillars in a well-patterned array format. In this way, the
number of micropillars each cell faces varies with its membrane
surface area, or the size of cells, as shown in Fig. 1a. In another
word, larger cells likely receive more electroporation locations and
area, which means more transient pores are created on their cell
membrane, but each pore is smaller when compared to the situation in bulk electroporation. Such a size-dependent pore formation
is hardly affected by the randomly located sites of cells as all micropillars are configured in a well-patterned array of a large scale. It
works like many single cell electroporation units are carried out in
parallel to treat millions of cells simultaneously with no need for cell
positioning. As every cell electroporation becomes representative in
MAE, the cellular uptake dynamics study on individual cells might
provide useful information in electroporation protocol
(a)
Micropillar Array with 6-µm pillar and 2-µm pitch
Micropillar Array with 2-µm pillar and 2-µm pitch
(b)
Fig. 1 (a) The cell size specific coverage mechanism of the micropillar array electroporation (MAE): large cells
face more micropillars with each providing focused electric pulse during electroporation; (b) a SEM image of
2-μm micropillars
4
Xuan Liu et al.
commercial systems. However, most of these microscale/nanoscale
systems still ignore the local electrical variation on individual cells
among a large population (i.e., bulk electroporation or BE), leaving
many uncontrollable factors similar to what in bulk electroporation
systems. For example, the randomness of cell allocation in the
buffer solution leads to random instead of uniform permeabilization of cells.
In this study, we developed a new micropillar array electroporation (MAE) approach to tackle this problem and accomplish cell
size specific electroporation. In MAE, cells are sandwiched between
a plain plate electrode and a plate electrode composed of thousands
of micropillars in a well-patterned array format. In this way, the
number of micropillars each cell faces varies with its membrane
surface area, or the size of cells, as shown in Fig. 1a. In another
word, larger cells likely receive more electroporation locations and
area, which means more transient pores are created on their cell
membrane, but each pore is smaller when compared to the situation in bulk electroporation. Such a size-dependent pore formation
is hardly affected by the randomly located sites of cells as all micropillars are configured in a well-patterned array of a large scale. It
works like many single cell electroporation units are carried out in
parallel to treat millions of cells simultaneously with no need for cell
positioning. As every cell electroporation becomes representative in
MAE, the cellular uptake dynamics study on individual cells might
provide useful information in electroporation protocol
(a)
Micropillar Array with 6-µm pillar and 2-µm pitch
Micropillar Array with 2-µm pillar and 2-µm pitch
(b)
Fig. 1 (a) The cell size specific coverage mechanism of the micropillar array electroporation (MAE): large cells
face more micropillars with each providing focused electric pulse during electroporation; (b) a SEM image of
2-μm micropillars
4
Xuan Liu et al.