Dual‐Function Plant‐Derived Nanovesicles From Regenerated <i>Cannabis sativa</i> Roots for Immunotherapy and Vaccine Delivery

Cannabis sativa is a medicinal plant that produces a diverse array of pharmacologically active metabolites, making it a valuable resource for pharmaceutical applications. In this study, an adventitious root (AR) culture system was established from C. sativa using two representative plant growth regulators-naphthaleneacetic acid (NAA; hereafter referred to as N-ARs) and indole-3-butyric acid (IBA; hereafter referred to as I-ARs) -from which plant-derived nanovesicles (PDNVs) were subsequently isolated (hereafter N-PDNVs and I-PDNVs, respectively). The resulting N-PDNVs and I-PDNVs exhibited average diameters of 128 ± 2 and 124 ± 4 nm, respectively, with zeta potentials of -12.9 and -15.7 mV. Both PDNV types maintained structural integrity and colloidal stability under diverse external stress conditions, underscoring their physicochemical robustness. Metabolite profiling of PDNVs revealed 25 distinct metabolites. Functionally, I-PDNVs markedly enhanced dendritic cell maturation through Toll-like receptor 2 (TLR2)- and TLR4-dependent pathways, promoted T cell proliferation and activation (notably IFN-γ- and IL-17A-producing subsets), and increased natural killer (NK) cell activity compared with N-PDNVs. In immunosuppressed and tumour-bearing mouse models, I-PDNVs further augmented NK cell, Th1 and cytotoxic T lymphocyte (CTL) responses, thereby confirming their superior potential as immunotherapeutic agents. Moreover, in immunized mouse models, OVA_257-264-encapsulated I-PDNVs demonstrated a clear advantage as a vaccine delivery platform by eliciting a potent OVA_257-264-specific CTL response. When applied as a prophylactic cancer vaccine, they not only delayed tumour growth but also reshaped the antitumour immune landscape, characterized by enhanced CTL responses, reduced regulatory T cell frequencies and diminished exhausted CD8⁺ T cell populations. Collectively, these findings highlight the potential of I-PDNVs as dual-function PDNVs, serving both as immunotherapeutic agents and as vaccine delivery platforms for applications requiring reinforced Th1, CTL and NK cell responses.