Electroporation-induced changes in tumor vasculature and microenvironment can promote the delivery and increase the efficacy of sorafenib nanoparticles

Blood vessels, the extracellular space, and the cell membrane represent physiologic barriers to nanoparticle-based drug delivery for cancer therapy. We demonstrate that electroporation (EP) can assist in the delivery of dye stabilized sorafenib nanoparticles (SFB-IR783) by increasing the permeability of endothelial monolayers, improving diffusion through the extracellular space in tumorspheres, and by disrupting plasma membrane function in cancer cells. These changes occur in a dose-dependent fashion, increasing proportionally with electric field strength. Cell death from irreversible electroporation (IRE) was observed to contribute to the persistent transport of SFB-IR783 through these physiologic barriers. In a model of mice bearing bilateral xenograft HCT116 colorectal tumors, treatment with EP resulted in the immediate and increased uptake of SFB-IR783 when compared with the untreated contralateral tumor. The uptake of SFB-IR783 was independent of direct transfection of cells through EP and was mediated by changes in vascular permeability and extracellular diffusion. The combination of EP and SFB-IR783 was observed to result in 40% reduction in mean tumor diameter when compared with sham treatment (p < .05) at the time of sacrifice, which was not observed in cohorts treated with EP alone or SFB-IR783 alone. Treatment of tumor with EP can augment the uptake and increase the efficacy of nanoparticle therapy.