Industrial crop-derived green nanomaterials for cancer research: Feedstock design, functional matching, and translational challenges

Industrial crops and agro-residues provide chemically diverse feedstocks for green nanomaterial development, but their value for cancer research depends on more than renewable origin. This review evaluates industrial crop-derived nanomaterials through a feedstock design-functional matching-translational challenge framework. Feedstock design is considered in terms of cellulose-rich biomass for cellulose nanocrystals and cellulose nanofibers, lignin-rich residues for nanolignin and redox-active carriers, phytochemical-rich tissues for plant-mediated metal and metal-oxide nanoparticles, carbon-rich residues for carbon dots and carbon-based hybrids, lipid-rich crops for lipid carriers, and edible or medicinal plant tissues for plant-derived vesicle-like nanoparticles. This review emphasizes that these material classes are not interchangeable anticancer systems. Nanocellulose and nanolignin are most suitable as drug-delivery matrices, hydrogels, stabilizing scaffolds, and redox-modulating carriers. Plant-mediated Ag, Au, ZnO, CuO, Fe-oxide, and Se nanoparticles are more closely associated with reactive oxygen species generation, apoptosis induction, imaging, magnetic response, or photothermal function. Biomass-derived carbon materials are better aligned with fluorescence imaging, photothermal therapy, photodynamic therapy, and theranostics, whereas lipid-based carriers and plant-derived vesicle-like nanoparticles are more relevant for cargo delivery, membrane interaction, and immunomodulation. Current evidence remains dominated by two-dimensional cancer-cell assays, which often overestimate anticancer performance because they do not reproduce serum protein interactions, tumor penetration barriers, heterogeneous enhanced permeability and retention effects, mononuclear phagocyte clearance, biodistribution, or long-term toxicity. Future advances in the field require standardized feedstock reporting, controlled synthesis, rigorous physicochemical characterization, reproducibility testing, phytochemical- and protein-corona analysis, function-matched cancer models, safety and clearance studies, and scalable production. This review presents industrial crop-derived nanomaterials as promising but technically demanding platforms for cancer applications, highlighting a rational matching between feedstock chemistry, nanoscale function, biological model, and translational feasibility.