Green synthesis nanoparticles for cancer immunotherapy: current applications and future perspectives

Green-synthesized nanoparticles (GSNPs) represent a developing paradigm in cancer immunotherapy, integrating principles of nanotechnology and bio-derived materials. These nanoparticles, produced via eco-friendly biological reductants from plants, microorganisms, or natural polymers, constitute a sustainable class of bioactive biomaterials that can directly interface with immune cells and tissues. Beyond their environmentally conscious synthesis, GSNPs often retain biofunctional moieties from natural sources, providing intrinsic antitumoral and immunomodulatory properties. Such dual behavior enables them to act simultaneously as cytotoxic and immune-activating biomaterials. Relevant literature was identified through searches of PubMed, Scopus, Web of Science, and Google Scholar for studies published between 2010 and 2026 using keywords related to green-synthesized nanoparticles, cancer immunotherapy, immune modulation, and the tumor immune microenvironment. This review comprehensively discusses the synthesis principles of GSNPs, their plant-, microbial-, and biopolymer-mediated fabrication routes, and their immune-modulating and tumoricidal mechanisms of relevance to biomaterial-cell interactions. GSNPs possess tunable physicochemical and biological characteristics that allow activation of macrophages, Th1 polarization, cytokine release, and attenuation of tumor-driven immune suppression. Furthermore, they act synergistically with checkpoint inhibitors or as nanovaccine platforms for antigen delivery. Through apoptosis induction, photothermal ablation, metabolic starvation, and modulation of NF-κB or PI3K/Akt signaling, GSNPs exert direct tumor-killing effects while maintaining biocompatibility.