Nanoelectropulse delivery for cell membrane perturbation and oxidation in human colon adenocarcinoma cells with drug resistance

Ultrashort electric pulses in the nanosecond range (nsPEF) can affect extra-and intracellular lipid structures and can also alternate cell functioning reversibly and irreversibly. Several of the nsPEF effects are due to the abrupt rise in intracellular free calcium levels and calcium ions influx from the outside. Calcium is one of the most important factors in cell proliferation, differentiation, and cell death (apoptosis or necrosis). Manipulating cal-cium levels using electroporation can have different effects on normal and malignant cells. This study aimed to examine the impact of nsPEFs, combined with 1 mM Ca2+ in human colon adenocarcinoma cell lines: sensitive-LoVo and drug resistant-LoVoDX. In this study 200 pulses of 10 ns and high voltage (12.5-50 kVcm(-1)) were used. Cell viability was determined by MTT and clonogenic assay. Proteasomal activity, GSH/GSSG assay, ROS pro-duction, and PALS-1 protein were evaluated as oxidative stress markers and protein damage. Cell morphology was visualized by AFM, SEM, and confocal microscopy imaging. The results revealed that nsPEF with 1 mM Ca2+ is cytotoxic, particularly for LoVoDX cells, and safe for normal cells. NsPEF provoked ROS release, altered cell polarity, and destabilized cell morphology. These results can be important for future protocols for colon adenocarcinoma using calcium nsPEF.

Automated summary

Ultrashort electric pulses in the nanosecond range can affect cell structures and functioning by altering calcium levels. This study examined the impact of nsPEFs combined with calcium on human colon adenocarcinoma cell lines. The results showed that nsPEF with calcium was cytotoxic for drug resistant cancer cells and safe for normal cells. The treatment also caused oxidative stress and altered cell morphology.