Referenced transfection efficiency and cell viability results on
multiple cell lines are given in Fig. 4, following the electroporation
conditions and procedures described above. Obvious transfection
enhancement is observed in MAE treatment, attributed to the
synergistic effects of the electric field focusing, localized electroporation, and size-dependent treatment. The first two effects benefit
for cell membrane permeabilization at benign pulse conditions and
its better recovery afterwards (see Notes 1 and 2), while the sizedependent treatment allocates the number and area of the transient
openings on individual cell membrane to ensure a homogeneous
treatment on cells of various sizes. The dimensions of individual
micropillar and their pitch size in the array affect the accuracy of
size-specific treatment and the enhancement level on cell transfection in MAE (see Fig. 5a and Note 3). Besides plasma transfection
improvement, MAE also shows similar delivery enhancement effect
for small oligonucleotides such as siRNA (see Fig. 5b and Note 4). It
is worth to point out that these tests are done under the same
electric pulse conditions (625 V/cm, single pulse with a duration
of 10 ms), which might not be best for some cell types. Further fine
tuning of the pulse conditions may be necessary for the best results
with different cell sources. The actual gap size between the two
electrodes of a MAE system is measured (see Note 5 for details) to
determine the pulse voltage prior to MAE treatment to ensure the
overall electric field strength is the same (625 V/cm) for both MAE
and BE systems.
0
mESC
293T
COS7
HeLa
A549
K562
mESC
293T
COS7
HeLa
A549
K562
20
40
MAE
BE
MAE
BE
60
80
100
0
20
40
60
80
100
(a)
(b)
Fig. 4 Transfection enhancement of pGFP plasmids in 2-μm micropillar MAE in several mammalian cell lines:
(a) quantitative results of transfection efficiency; (b) cell viability. “BE” for bulk electroporation with a BTX
commercial electroporator
Cell Size-Specific Transfection by Micropillar Array Electroporation
9
multiple cell lines are given in Fig. 4, following the electroporation
conditions and procedures described above. Obvious transfection
enhancement is observed in MAE treatment, attributed to the
synergistic effects of the electric field focusing, localized electroporation, and size-dependent treatment. The first two effects benefit
for cell membrane permeabilization at benign pulse conditions and
its better recovery afterwards (see Notes 1 and 2), while the sizedependent treatment allocates the number and area of the transient
openings on individual cell membrane to ensure a homogeneous
treatment on cells of various sizes. The dimensions of individual
micropillar and their pitch size in the array affect the accuracy of
size-specific treatment and the enhancement level on cell transfection in MAE (see Fig. 5a and Note 3). Besides plasma transfection
improvement, MAE also shows similar delivery enhancement effect
for small oligonucleotides such as siRNA (see Fig. 5b and Note 4). It
is worth to point out that these tests are done under the same
electric pulse conditions (625 V/cm, single pulse with a duration
of 10 ms), which might not be best for some cell types. Further fine
tuning of the pulse conditions may be necessary for the best results
with different cell sources. The actual gap size between the two
electrodes of a MAE system is measured (see Note 5 for details) to
determine the pulse voltage prior to MAE treatment to ensure the
overall electric field strength is the same (625 V/cm) for both MAE
and BE systems.
0
mESC
293T
COS7
HeLa
A549
K562
mESC
293T
COS7
HeLa
A549
K562
20
40
MAE
BE
MAE
BE
60
80
100
0
20
40
60
80
100
(a)
(b)
Fig. 4 Transfection enhancement of pGFP plasmids in 2-μm micropillar MAE in several mammalian cell lines:
(a) quantitative results of transfection efficiency; (b) cell viability. “BE” for bulk electroporation with a BTX
commercial electroporator
Cell Size-Specific Transfection by Micropillar Array Electroporation
9