The application of irreversible electroporation (IRE) to endoluminal organs is being investigated; however, the current preclinical evidence and optimized electrodes are insufficient for clinical translation. Here, a novel self-expandable electrode (SE) made of chemically polished nickel-titanium (Ni-Ti) alloy wire for endoluminal IRE is developed in this study. Chemically polished heat-treated Ni-Ti alloy wires demonstrate increased electrical conductivity, reduced carbon and oxygen levels, and good mechanical and self-expanding properties. Bipolar IRE using chemically polished Ni-Ti wires successfully induces cancer cell death. IRE-treated potato tissue shows irreversibly and reversibly electroporated areas containing dead cells in an electrical strength-dependent manner. In vivo study using an optimized electric field strength demonstrates that endobiliary IRE using the SE evenly induces well-distributed mucosal injuries in the common bile duct (CBD) with the overexpression of the TUNEL, HSP70, and inflammatory cells without ductal perforation or stricture formation. This study demonstrates the basic concept of the endobiliary IRE procedure, which is technically feasible and safe in a porcine CBD as a novel therapeutic strategy for malignant biliary obstruction. The SE is a promising electrical energy delivery platform for effectively treating endoluminal organs.
Keywords: chemical polishing; electrode; irreversible electroporation; nickel-titanium alloys; self-expandable metallic stents.