Undrakh Ganbaatar

Supplemental Figure 2. Estimation of cell death within 3-dimensional hydrogel tissue mimic following treatment with IRE and sIRE.

Supplemental Table 3. Pulse parameters used for conventional IRE and sIRE.

Supplemental Figure 3. Fluorescent imaging of IRE and sIRE treatment effects on (A) MSTO-GM, (B) untransduced, and (C) CAR T cells embedded in 3D collagen mimics that were treated with various parameters of sIRE or IRE 24 hours post-treatment in vitro. 4x magnification images were scanned and stitched to illustrate PEF treatment area of effect within the whole well of a 24-well using a 2-pin probe electrodes with 4 mm spacing. Dead cells were identified by propidium iodide (red) and live cells identified with Calcein AM (green). (D–F) Area of cell death were quantified using script on FIJI ImageJ. Scale bar = 4 mm.

Supplemental Figure 4. Intratumoral T cell viability after sIRE or IRE in an immunocompetent syngeneic flank tumor model.

Supplemental Figure 7. sIRE promotes infiltration of CAR T cells with minimal killing of preexisting intratumoral T cells.

Supplemental Figure 5. Transwell migration assay of CAR T cells when exposed to sIRE and IRE conditioned media in vitro.

Supplemental Figure 1. Mesothelioma and T cell viability at 24 hours post-IRE in vitro. Mesothelioma cell lines.

Supplemental Table 2. Cell viability material properties.

Purpose:One recurring challenge in cell therapy for solid tumors is poor tumor infiltration of adoptively transferred T cells. We previously showed that a subablative dose of tumor-targeted radiation generates a chemokine gradient that promotes infiltration, proliferation, and a memory phenotype of chimeric antigen receptor (CAR) T cells in solid tumors. However, radiation is cytotoxic to infiltrating CAR T cells, limiting its repeated use.Experimental Design:We hypothesized that irreversible electroporation could generate a chemokine gradient that promotes CAR T-cell infiltration into solid tumors and that selective irreversible electroporation (sIRE) tuned for selective cancer cell lysis (thus sparing infiltrating CAR T cells) can be used in a repeated fashion. Using experimental screening and simulation models, we optimized sIRE parameters to kill cancer cells while sparing T cells.Results:Using 3D tumor mimics and mouse models of malignant pleural mesothelioma, we confirmed the therapeutic benefit of repeated sIRE. Chemokine secretion by cancer cells injured by sIRE promoted migration and tumor infiltration of systemically administered CAR T cells and facilitated sustained immunity in a tumor-rechallenge model.Conclusions:By leveraging a dual-purpose translational strategy—through direct cancer cell–targeted cytotoxicity and augmented CAR T-cell infiltration—sIRE can reduce cancer burden while preserving and enhancing CAR T-cell function.

Supplemental Figure 6. Flow cytometry analysis of T cell populations in blood samples was carried out from mice treated with intravenous CAR T cells, sIRE, or combinational therapy (sIRE + CAR & sIRE + CAR + sIRE).