ELECTROPORATION OF CARDIOMYOCYTES IN-VITRO IN 2-D CULTURE (YOUNG INVESTIGATOR AWARD COMPETITION)

Aim
Electroporation is a bioelectrical technique that applies short electrical pulses to create pores in the cytoplasmic membrane of cells. This method facilitates entry of large molecules into cells without induction of cell death (reversible electroporation) or induces cell death (irreversible electroporation). The aim of this study is to investigate electroporation protocols that can induce both types of electroporation in adherent cardiomyocytes.
Methods
A tumor line of murine cardiomyocytes was used for this study. Electroporation was conducted using a commercial TONAPULSE electrical pulse generator equipped with an electrode plate (TONAGENA, CZ). Cardiomyocytes were exposed to a burst consisting of 216 bipolar pulses lasting 2 μs, with 5 μs pauses in between of the pulses. Each burst was repeated 20 times with a 1 second pause between. Applied electric fields ranged from 250 V/cm to 1500 V/cm. The ratio of viable to non-viable cells was assessed at 1 hour and 24 hours post-electroporation with fluorescent microscopy.
Results
Electric fields of 250 and 500 V/cm (induced reversible electroporation), did not result in a higher rate of cell death. With increasing of electric field, cell death was induced. Electric field 750 V/cm induced cell death in 27 ± 6 % of cardiomyocytes, while 1000 V/cm resulted in 44 ± 6 %, 1250 V/cm in 56 ± 7 %, and 1500 V/cm in 75 ± 18 % (fig. 1). Similar ratio of cell death was observed after 24 hours.
Conclusion
The electric field for reversible electroporation - 250 and 500 V/cm did not induce cell death. However, electric fields for irreversible electroporation - 750 to 1500 V/cm resulted in cell death. This experiment validates the feasibility of achieving either reversible or irreversible electroporation in 2D cultures of cardiomyocytes, depending solely on the strength of the applied electric field.