Doxorubicin delivery enhanced by electroporation to gastrointestinal adenocarcinoma cells with P-gp overexpression.

Electroporation (EP) can effectively support the penetration of macromolecules from the extracellular space into cells. Electropores induced by the influence of electromagnetic field generate additional paths of transport for macromolecules. The aim of this study was evaluation of the electroporation effect on doxorubicin transport efficiency to human colon (LoVo and LoVo/DX) and gastric (EPG85-257/P and EPG85-257/RDB) adenocarcinoma cells with overexpression of P-glycoprotein and murine macrophage cell line (P388/D1). In our EP experiments cells were placed into a cuvette with aluminum electrodes and pulsed with five square electric pulses of 1300 V/cm and duration of 50 μs each. Cells were also treated with low doxorubicin concentration ([DOX]=1.7 μM). The ultrastructure (TEM) and changes of P-glycoprotein expression of tumor cells subjected to electric field were monitored. The mitochondrial cell function and trypan blue staining were evaluated after 24h. Our results indicate the most pronounced effect of EP with DOX and disturbed ultrastructure in resistant gastric and colon cells with decrease of P-gp expression. Electroporation may be an attractive delivery method of cytostatic drugs in chemotherapy, enabling reduction of drug dose, exposure time and side effects.