340 - Nano-enabled Irreversible Electroporation Ablation Immunotherapy Using M1 Macrophage Cell Membrane–Coated Nanogel

Purpose: Irreversible electroporation (IRE) is a promising non-thermal ablation technique that induces both local tumor cell death and systemic immune responses. However, the immunomodulatory impact of nano-enabled IRE immunotherapy approaches with immune-stimulating nanomaterials remains underexplored. This study evaluated the therapeutic potential of a nano-enabled IRE-Immunotherapy combination using a novel M1 macrophage cell membrane–coated nanogel containing graphene quantum dots and zoledronate (M1-GAZ).

Materials and Methods: M1-GAZ was prepared by mixing sodium alginate solution with graphene quantum dots and zoledronate, followed by aluminum ion-induced gelation. Then, M1 macrophage cell membranes were coated on the surface of M1-GAZ through multiple extrusion cycles. CT26 colon carcinoma tumors were established subcutaneously in BALB/c mice. IRE (1000 V, 100 µs, 80 pulse, 5 mm electrode spacing) was performed, followed by intravenous administration of M1-GAZ. Tumor targeting and biodistribution of M1-GAZ were evaluated using IVIS imaging. Tumor growth was monitored for up to 24 days. Immune cell infiltration and activation (CD4⁺/CD8⁺ T cells, NK cells, dendritic cells, macrophages, neutrophils) were assessed in spleen and tumor tissues by flow cytometry and histology at day 3 post-treatment.

Results: M1-GAZ demonstrated efficient tumor targeting after IRE, with greater accumulation than control nanoparticles. Nano-enabled IRE-immunotherapy (IRE + M1-GAZ) significantly enhanced the inhibition of tumor growth and infiltration of CD8⁺ T cells, NK cells, and dendritic cells within the tumor microenvironment compared to IRE alone. Augmented systemic immune activation was also demonstrated in the spleen at day 3. Histological analysis confirmed greater tumor necrosis in the nano-enabled IRE-immunotherapy group compared with either monotherapy. No notable toxicity was observed in major organs.

Conclusion: Nano-enabled IRE immunotherapy using M1-GAZ nanogel showed a translational potential with its synergistically enhanced tumor ablation and early immune activation in a solid colon tumor model.