The aim of the study was to evaluate changes in the cytoskeleton and integrity of the monolayer of human microvascular endothelial cells (HMEC-1) in vitro after exposure to electroporation or electrochemotherapy with bleomycin. We demonstrated that exposure to electric pulses alone affects cell morphology, additional alterations were observed also for the cytoskeletal proteins F-actin and beta-tubulin. During both electroporation and electrochemotherapy, the initial phase of cellular damage was noticed at 10 min as swollen cells and honeycomb-like actin bundles. The electroporation-induced cellular effects, observed from electric pulses above 150 V, were voltage-dependent and within 24 hrs partly recoverable. The electrochemotherapy-induced cellular effects developed at 2 hrs in spindle-like cells, and more densely packed F-actin and Beta-tubulin were observed, which were dependent on the amount of bleomycin and the voltages applied. In addition, for electrochemotherapy with electric pulses above 150 V cellular changes were not recoverable within 24 hrs. The effects on monolayer integrity were reflected in the enhanced monolayer permeability, with the electrochemotherapy showing an earlier onset. We conclude that electrochemotherapy as compared to electroporation leads within 24 hrs to a quicker and more pronounced monolayer integrity damage and endothelial cell death, which together provide further insight into the cellular changes of the vascular disruption of electrochemotherapy.
COBISS.SI-ID: 1409403
The aim of our present study was to understand and explain the effects of electropermeabilization on the dynamics (vasomotricity, permeability and recovery) of subcutaneous blood vessels. These features were studied via a dorsal skin fold window chamber, using fluorescently labeled dextrans of different sizes, intravital fluorescence microscopy imaging and specific image analysis. Application of electric pulses on the skin in vivo resulted in a rapid increase in vascular permeability that gradually recovered to basal levels at different times post-treatment, depending on dextran size. Simultaneously, the immediate constriction of the blood vessels occurred that was more pronounced for arterioles compared to venules. This vasoconstriction of arterioles results in a transient "vascular lock". The increased permeability of small vessels walls whatever the dextran size associated with delayed perfusion explains the improved delivery of the intravenous injected molecules (i.e. drugs, gene delivery) into the tissues induced by electropermeabilization in vivo.
COBISS.SI-ID: 1348475
The aim of the study was to investigate the effect of a combination of high-voltage (HV) and low-voltage (LV) pulses on skin-vessel blood flow using intravital microscopy in a dorsal window chamber in mice and fluorescently labeled dextrans. Image analysis of fluorescence intensity changes demonstrated that electroporation induces a transient constriction and increased permeability of blood vessels as well as a "vascular lock". In conclusion, our results show that blood flow modifying effects of EP in skin contribute to the infiltration of immune cells in the exposed area. When combined with plasmid DNA for vaccination, this could enable the initial and prolonged contact of immune cells with encoded therapeutic proteins.
COBISS.SI-ID: 1293435