Impact of the Cell-Spread and Ablation Imaging Technique on Irreversible Electroporation of MCF-7-seeded Hydrogels

Tumor ablation may be achieved by irreversible electroporation (IRE) as a non-thermal, minimally-invasive procedure. Particularly, malignant breast tumors are an important tissue to target by IRE. This work presents MCF-7-seeded hydrogels as an analogue framework to in vivo tumors to evaluate the effects of IRE in breast cancer. The experimental ablation extent was imaged in a small surface (1.2 mm x 1.0 mm) in the center of the hydrogel by epifluorescence microscopy. The ablation extent in the complete hydrogels was solved through a computational model considering a homogeneous hydrogel surrounding a central block of MCF-cells heterogeneously spread within extracellular matrix. The electric field distribution revealed that 82% of the hydrogel undergoes more than 400 V/cm and is hence likely to achieve IRE. This distribution was contrasted against the experimental cell-death extent to determine the electric field threshold for IRE of MCF-7 cells as 549.16 V/cm (heterogeneous block) and 728.61 V/cm (homogeneous hydrogel) which are consistent with the values reported for liver, and pancreatic tumors in vivo.