The estimation of pore size distribution of electroporated MCF-7 cell membrane

ABSTRACT

The size of the pores created by external electrical pulses is important for molecule delivery into the cell. The size of pores and their distribution on the cell membrane determine the efficiency of molecule transport into the cell. There are very few studies visualizing the presence of electropores. In this study, we aimed to investigate the size distribution of electropores that were created by high intensity and short duration electrical pulses on MCF-7 cell membrane. Scanning Electron Microscopy (SEM) was used to visualize and characterize the membrane pores created by the external electric field. Structural changes on the surface of the electroporated cell membrane was observed by Atomic Force Microscopy (AFM). The size distribution of pore sizes was obtained by measuring the radius of 500 electropores. SEM imaging showed non-uniform patterning. The average radius of the electropores was 12 nm, 51.60% of pores were distributed within the range of 5 to 10 nm, and 81% of pores had radius below 15 nm. These results showed that microsecond (µs) high intensity electrical pulses cause the creation of heterogeneous nanopores on the cell membrane.

Plain Language Summary

Electroporation is a phenomenon in which permeability of the cell membrane to molecules and ions is increased due to externally applied high electric field pulses. The externally applied electric field pulses create pores on the cell membrane, allowing ions and molecules that normally can not pass through the membrane. The transport of molecules into the cell is related to the size and distribution of the pores created on the membrane. Studies visualizing the presence of electropores are very limited. In this study, we aimed to visualize pores and determine the size distribution of pores created due to the application of external electric field pulses on the cell membrane of human breast cancer cells. The membrane pores created by external electric field were visualized and characterized by different imaging techniques. The size distribution of pores was obtained by measuring the radius of 500 pores created on the cell membrane due to the applied electric fields. The surface of the electropermeabilized cells were very rough due to deformation during electroporation. We observed heterogeneous pore populations that were formed due to application of external electrical pulses on the surface of cell membrane. The average radius of the pores was found to be 12 nm.

KEYWORDS:

• Electroporation
• pore formation
• human breast cancer cell
• electropermeabilization
• scanning electron microscopy
• atomic force microscopy

Acknowledgments

The authors thank Prof Dr. Ongun Onaran for his technical assistance.

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No potential conflict of interest was reported by the author(s).

Author Interest Statement

All authors declare that they have no conflicts of interest.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.