Nanosecond Electric Pulses as a Novel In Situ Vaccination Strategy for Cancer Treatment: Mechanisms, Challenges and...

Nanosecond electric pulses (nsEPs) are an emerging pulsed-power technology with unique bioelectric characteristics distinct from conventional long-pulse electroporation. As a tunable physical modality, nsEPs can modulate intracellular structures, membrane dynamics, and signaling pathways. Increasing evidence supports nsEPs as a promising non-thermal tumor ablation approach due to their high spatial precision, preservation of critical tissue structures, and minimal adverse effects. One of the most significant discoveries associated with nsEP tumor ablation is the induction of potent systemic antitumor immunity, particularly in situ vaccination (ISV) effects and, in some cases, abscopal effects against distant untreated tumors. Substantial evidence demonstrates that nsEPs can function as authentic immunogenic cell death (ICD) inducers by promoting the release of damage-associated molecular patterns (DAMPs), including calreticulin (CRT), ATP, and HMGB1. These events facilitate dendritic cell activation, antigen presentation, and the generation of long-term antitumor T-cell immunity. In addition to enhancing tumor immunogenicity, nsEPs profoundly remodel the tumor microenvironment (TME), including disruption of tumor vasculature, reduction in immunosuppressive cell populations, and alteration of stromal components. Emerging studies further suggest that nsEPs act as electric metabolic modulators capable of influencing mitochondrial function, calcium signaling, and metabolism-associated signaling pathways. Current evidence indicates that the immunological outcomes induced by nsEPs are highly dependent on pulse parameters, waveform characteristics, and tumor type. Despite its considerable therapeutic promise, the development of nsEP-induced ISV immunotherapy faces several important challenges, including standardization and optimization of pulse protocols, identification of critical molecular and cellular targets, and clarification of tumor- and cell-type-specific responses. Addressing these challenges through multidisciplinary collaboration and advanced technologies, including multi-omics, spatial analysis, and computational modeling, may accelerate the development of next-generation bioelectric immunotherapies for cancer treatment.