Electrochemotherapy is an e cient method for the local treatment of cutaneous and subcutaneous metastases, but its e cacy as a systemic treatment remains low. The application of gene electrotransfer (GET) to transfer DNA coding for immune system modulating molecules could allow for a systemic e ect, but its applications are limited because of possible side e ects, e.g., immune system overactivation and autoimmune response. In this paper, we present the simultaneous electrotransfer of bleomycin and plasmid DNA as a method to increase the systemic e ect of bleomycin-based electrochemotherapy. With appropriately selected concentrations of bleomycin and plasmid DNA, it is possible to achieve e cient cell transfection while killing cells via the cytotoxic e ect of bleomycin at later time points. We also show the dynamics of both cell electrotransfection and cell death after the simultaneous electrotransfer of bleomycin and plasmid DNA. Therefore, this method could have applications in achieving the transient, cell death-controlled expression of immune system activating genes while retaining e cient bleomycin mediated cell killing.

Electroporation is a widely established method for molecular delivery across electric field perturbed plasma membrane. It can be used as a non-viral DNA transfection method, or as a way to achieve small molecule delivery to or extraction from cells. We examined the possibility of combining the DNA delivery to the cells with small molecule transport across electroporated plasma membrane. The results show that the presence of DNA in electroporation medium increases the extraction of fluorescent dye calcein from calcein-AM loaded cells as well as the delivery of small-molecule drug bleomycin to the cells. We propose that these results may have implications in enhanced drug delivery using electroporation both in vivo and in clinics.