Limits...
Lucifer Yellow uptake by CHO cells exposed to magnetic and electric pulses.

Towhidi L, Firoozabadi SM, Mozdarani H, Miklavcic D - Radiol Oncol (2012)

Bottom Line: The Chinese hamster ovary (CHO) cells were exposed to magnetic pulses of 2.2 T peak strength and 250 μs duration delivered by Magstim stimulator and double 70 mm coil.Three different frequencies of 0.25, 1 and 10 Hz pulses with 112, 56 and 28 number of pulses were applied (altogether nine experimental groups) and Lucifer Yellow uptake was measured in each group.Our results show that time-varying magnetic field exposure increases transmembrane molecular transport and this uptake is greater for lower frequencies and larger number of pulses.

View Article: PubMed Central - PubMed

Affiliation: Tarbiat Modares University, Department of Medical Physics, Tehran, Iran ; University of Ljubljana, Faculty of Electrical Engineering, Ljubljana, Slovenia.

ABSTRACT

Background: The cell membrane acts as a barrier that hinders free entrance of most hydrophilic molecules into the cell. Due to numerous applications in medicine, biology and biotechnology, the introduction of impermeant molecules into biological cells has drawn considerable attention in the past years. One of the most famous methods in this field is electroporation, in which electric pulses with high intensity and short duration are applied to the cells. The aim of our study was to investigate the effect of time-varying magnetic field with different parameters on transmembrane molecular transport.

Materials and methods: 'Moreover, a comparison was made between the uptake results due to magnetic pulse exposure and electroporation mediated uptake.' at the end of Background part. The Chinese hamster ovary (CHO) cells were exposed to magnetic pulses of 2.2 T peak strength and 250 μs duration delivered by Magstim stimulator and double 70 mm coil. Three different frequencies of 0.25, 1 and 10 Hz pulses with 112, 56 and 28 number of pulses were applied (altogether nine experimental groups) and Lucifer Yellow uptake was measured in each group. Moreover, maximum uptake of Lucifer Yellow obtained by magnetic pulses was compared to the measured uptake due to electroporation with typical parameters of 8 pulses of 100 μs, repetition frequency of 1 Hz and electric field intensities of 200 to 600 V/cm.

Results and conclusions: Our results show that time-varying magnetic field exposure increases transmembrane molecular transport and this uptake is greater for lower frequencies and larger number of pulses. Besides, the comparison shows that electroporation is more effective than pulsed magnetic field, but the observed uptake enhancement due to magnetic exposure is still considerable.

No MeSH data available.


Related in: MedlinePlus

Dye uptake of attached CHO cells. The white bar shows the control group normalized to 100. The fluorescence of other groups was computed as the percent of control fluorescence. The gray bars show uptake attributed to different electric field exposure amplitudes of 8 pulses of 100 μs and 1 Hz for electroporation experiments. The dashed line demonstrates the greatest uptake of cells due to magnetic field exposure (112 pulses of 0.25 Hz). Vertical bars represent standard deviation of the mean.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC3472937&req=5

f3-rado-46-02-119: Dye uptake of attached CHO cells. The white bar shows the control group normalized to 100. The fluorescence of other groups was computed as the percent of control fluorescence. The gray bars show uptake attributed to different electric field exposure amplitudes of 8 pulses of 100 μs and 1 Hz for electroporation experiments. The dashed line demonstrates the greatest uptake of cells due to magnetic field exposure (112 pulses of 0.25 Hz). Vertical bars represent standard deviation of the mean.

Mentions: In order to compare cell exposure to magnetic pulses with the conventional method for membrane permeability increase (i.e. electroporation), the uptake enhancement of attached CHO cells due to determined applied electric pulses were also investigated. The cells were exposed to 8 pulses of 100 μs duration and 1 Hz pulse repetition frequency of five different electric field intensities (200 to 600 V/cm with 100 V/cm increment). The resulted value for cellular uptake of LY due to electroporation with different pulse amplitudes are displayed in gray in Figure 3. For an easier comparison, the highest measured fluorescence of cells due to the magnetic pulse exposure (112 pulses of 0.25 Hz) is shown with dashed line. The control group is illustrated in white. The comparisons of the uptake between the control group, groups exposed to electric pulses and groups exposed to magnetic pulses were performed using the Mann-Whitney Rank-Sum test. The results of this comparison show that with selected parameters of electric and magnetic exposures, both give rises to the uptake enhancement and have a significant difference with the control group. Although the results show that all the electric pulse exposure groups, except the one with 600 V/cm field strength, were significantly more effective than magnetic pulse exposure groups (Figure 3).


Lucifer Yellow uptake by CHO cells exposed to magnetic and electric pulses.

Towhidi L, Firoozabadi SM, Mozdarani H, Miklavcic D - Radiol Oncol (2012)

Dye uptake of attached CHO cells. The white bar shows the control group normalized to 100. The fluorescence of other groups was computed as the percent of control fluorescence. The gray bars show uptake attributed to different electric field exposure amplitudes of 8 pulses of 100 μs and 1 Hz for electroporation experiments. The dashed line demonstrates the greatest uptake of cells due to magnetic field exposure (112 pulses of 0.25 Hz). Vertical bars represent standard deviation of the mean.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3472937&req=5

f3-rado-46-02-119: Dye uptake of attached CHO cells. The white bar shows the control group normalized to 100. The fluorescence of other groups was computed as the percent of control fluorescence. The gray bars show uptake attributed to different electric field exposure amplitudes of 8 pulses of 100 μs and 1 Hz for electroporation experiments. The dashed line demonstrates the greatest uptake of cells due to magnetic field exposure (112 pulses of 0.25 Hz). Vertical bars represent standard deviation of the mean.
Mentions: In order to compare cell exposure to magnetic pulses with the conventional method for membrane permeability increase (i.e. electroporation), the uptake enhancement of attached CHO cells due to determined applied electric pulses were also investigated. The cells were exposed to 8 pulses of 100 μs duration and 1 Hz pulse repetition frequency of five different electric field intensities (200 to 600 V/cm with 100 V/cm increment). The resulted value for cellular uptake of LY due to electroporation with different pulse amplitudes are displayed in gray in Figure 3. For an easier comparison, the highest measured fluorescence of cells due to the magnetic pulse exposure (112 pulses of 0.25 Hz) is shown with dashed line. The control group is illustrated in white. The comparisons of the uptake between the control group, groups exposed to electric pulses and groups exposed to magnetic pulses were performed using the Mann-Whitney Rank-Sum test. The results of this comparison show that with selected parameters of electric and magnetic exposures, both give rises to the uptake enhancement and have a significant difference with the control group. Although the results show that all the electric pulse exposure groups, except the one with 600 V/cm field strength, were significantly more effective than magnetic pulse exposure groups (Figure 3).

Bottom Line: The Chinese hamster ovary (CHO) cells were exposed to magnetic pulses of 2.2 T peak strength and 250 μs duration delivered by Magstim stimulator and double 70 mm coil.Three different frequencies of 0.25, 1 and 10 Hz pulses with 112, 56 and 28 number of pulses were applied (altogether nine experimental groups) and Lucifer Yellow uptake was measured in each group.Our results show that time-varying magnetic field exposure increases transmembrane molecular transport and this uptake is greater for lower frequencies and larger number of pulses.

View Article: PubMed Central - PubMed

Affiliation: Tarbiat Modares University, Department of Medical Physics, Tehran, Iran ; University of Ljubljana, Faculty of Electrical Engineering, Ljubljana, Slovenia.

ABSTRACT

Background: The cell membrane acts as a barrier that hinders free entrance of most hydrophilic molecules into the cell. Due to numerous applications in medicine, biology and biotechnology, the introduction of impermeant molecules into biological cells has drawn considerable attention in the past years. One of the most famous methods in this field is electroporation, in which electric pulses with high intensity and short duration are applied to the cells. The aim of our study was to investigate the effect of time-varying magnetic field with different parameters on transmembrane molecular transport.

Materials and methods: 'Moreover, a comparison was made between the uptake results due to magnetic pulse exposure and electroporation mediated uptake.' at the end of Background part. The Chinese hamster ovary (CHO) cells were exposed to magnetic pulses of 2.2 T peak strength and 250 μs duration delivered by Magstim stimulator and double 70 mm coil. Three different frequencies of 0.25, 1 and 10 Hz pulses with 112, 56 and 28 number of pulses were applied (altogether nine experimental groups) and Lucifer Yellow uptake was measured in each group. Moreover, maximum uptake of Lucifer Yellow obtained by magnetic pulses was compared to the measured uptake due to electroporation with typical parameters of 8 pulses of 100 μs, repetition frequency of 1 Hz and electric field intensities of 200 to 600 V/cm.

Results and conclusions: Our results show that time-varying magnetic field exposure increases transmembrane molecular transport and this uptake is greater for lower frequencies and larger number of pulses. Besides, the comparison shows that electroporation is more effective than pulsed magnetic field, but the observed uptake enhancement due to magnetic exposure is still considerable.

No MeSH data available.


Related in: MedlinePlus