Abstract No. 160 Enhanced Combinational Immuno-Irreversible Electroporation Ablation Therapy Using Highly Conductive Metal Nanofilms for the Treatment of Hepatocellular Carcinoma

To evaluate enhanced therapeutic efficacy of irreversible electroporation (IRE) ablation using highly conductive metal nanofilms and their synergistic combination with aPD-L1 immunotherapy in vitro and in vivo N1S1 orthotopic HCC rat model Mxenes, consisting of atomically thin layers of metals (Ti3C2 and Ta4C3), were prepared based on previously reported. Enhanced cell ablation efficacy of Mxene-IRE (0.1 mg/mL, 0.5-1 kV, 8-20 pluses) was assessed with CCK assay compared with IRE alone. The therapy catalytic effect of Mxene in IRE was investigated by analyzing cellular membrane damages (BODIPY and YO-PRO-3) and cellular ion channels such as Ca2+ (Fluo-8) and K+ (Flux OR Green) assay. N1S1 orthotopic HCC rat models were subjected to IRE only (n=6, 2 kV, 40 pulses), Mxene-IRE (Mxene: 10 mg/kg, n=6), aPL-L1-Mxene-IRE groups were additionally infused with aPD-L1 (10 mg/kg, each IA and IV administration, n=6/6). Non-treated HCC rats were assigned as a control group (n = 6). Tumors were observed with 7T MRI or CT and the landscape of immune cells was analyzed using multiplex full spectrum CyTEK technique. Highly conductive Mxene-catalyzed IRE demonstrated significantly enhanced cancer cell killing with minimizing reversible cell survival. In the mechanism study, Mxene during IRE significantly generated ROS and nanopores on the cellular membrane. The conductive Mxene cellular patches randomly disrupted voltage-gated ion channels (Ca2+ and K+). In vivo results also demonstrated higher HCC ablation efficacy of Mxene-IRE compared to IRE only group. When local aPD-L1 immunotherapy was added in Mxene-IRE, tumors could be rejected within 7 days. High-dimensional immune analysis showed significant infiltration of CD8+ T cells expressing the activation marker (PD-1+ or IFNγ+), suppression of MDSC and Treg population, and systemic memory T cells induction in the Mxene-IRE-aPD-L1 treated tumor tissues. Enhanced IRE ablation cancer therapy minimizing reversible cancer cell survival was achieved with highly conductive Mxene. Their combination therapy with aPD-L1 has the potential for complete tumor removal and reduction of tumor recurrence.