Jacobs, E. J. | Search bioRxiv

bioRxiv2026

Bioimpedance-assisted characterization of cardiac electroporation and anisotropic homogenization by pulsed field ablation

ObjectivePulsed field ablation (PFA) relies on irreversible electroporation to create nonthermal cardiac lesions, yet real-time indicators of electroporation progression and validated lethal electric field thresholds remain limited. This study aimed to develop a bioimpedance-based metric for real-time monitoring of cardiac electroporation, evaluate the impact of myocardial anisotropy under electroporation conditions, and derive waveform-specific lethal electric field thresholds. IntroductionCurrent PFA procedures lack direct intraoperative feedback on lesion formation, and uncertainty remains regarding the role of myocardial fiber orientation in shaping electric field distributions. Because electroporation dynamically alters tissue electrical properties, monitoring these changes during treatment may improve prediction of ablation outcomes. MethodsPFA was delivered to fresh ex vivo porcine ventricular tissue using clinically relevant and energy-matched waveforms with pulse widths from 1 to 100 {micro}s. Inter-burst broadband electrical impedance spectroscopy was performed using a low-voltage diagnostic waveform to quantify burst-resolved impedance changes. Lesions were visualized using metabolic staining, then finite element models incorporating nonlinear electroporation-dependent conductivity were used to compare anisotropic and homogenized electric field distributions. Lethal electric field thresholds were estimated by fitting simulated contours to measured lesion areas and validated using uniform electric fields generated by a parallel electrode array. ResultsAcross all waveforms, impedance measurements showed a rapid initial decrease followed by stabilization, indicating early electroporation saturation. Burst-to-burst percent change in impedance slope provided a consistent, waveform-agnostic metric of electroporation progression. Lesion morphology was not systematically influenced by fiber orientation, and modeling demonstrated that electroporation-induced conductivity increases homogenized tissue anisotropy. Lethal electric field thresholds increased with decreasing pulse width, ranging from 517 {+/-} 46 V/cm (100 {micro}s) to 1405 {+/-} 55 V/cm (1 {micro}s), and were validated under uniform field conditions. ConclusionBioimpedance-assisted monitoring enables real-time assessment of cardiac electroporation, while electroporation-induced homogenization supports simplified modeling and standardized PFA treatment design.

bioengineering↗

bioRxiv2025

Novel combination of irreversible electroporation and allogenic chimeric antigen receptor (CAR) T-cell therapy synergizes therapeutic outcomes in a preclinical human pancreatic cancer mouse model

Irreversible electroporation (IRE) is a non-thermal ablation modality used clinically for treating unresectable tumors while preserving vital structures through controlled application of pulsed electric fields. Previous data suggest that patient outcomes are enhanced with the induction of an anti-tumor immune response, but current research focuses on using immune checkpoint inhibitors, which function through conventional immune pathways that may be downregulated by cancer or dysregulated by chemo-induced lymphodepletion. Chimeric Antigen Receptor (CAR) T-cells overcome this limitation, as they are engineered with synthetic receptors that redirect lymphocytes to recognize and target cells expressing tumor-specific structures. CARs are engineered to have an increased binding affinity compared to in-situ T-cell binding, amplify internal stimulation cascades, and release pro-inflammatory cytokines that can modulate the endogenous immune system. However, there are still major limitations for adoptive cell therapies in solid tumors, including life-threatening on-target off-tumor cytotoxicity, antigen escape, and failure to infiltrate and persist in solid tumors. Given the substantial evidence that IRE overcomes many of the challenges associated with immune infiltration and persistence in solid tumors, there is a strong premise for using targeted cell therapies following IRE, which would then target residual cancer that could repopulate the lesion. Here, we present the first proof-of-concept combination of IRE with an adoptive cell therapy. We validated that the cell membrane CAR target is not affected in electroporated cells that survive IRE, allowing for subsequent binding and elimination of residual tumor. The research demonstrates the feasibility and synergy of a novel combination of two clinically used techniques.

cancer biology↗