Biogenic Metal Nanoparticles from Indian Flora as Programmable Bio-Interfaces: From Phytochemical Coronas to Precision Nanomedicine

Biogenic metal nanoparticles are naturally covered with the phytochemical corona, which includes plant-derived metabolites. Emerging evidence suggests that the phytochemical corona, together with the intrinsic properties of the metallic core, contributes significantly to the biological identity, therapeutic behavior, and safety profile of biogenic nanoparticles. In this review, we go beyond the traditional view of plant extracts as reducing and capping agents to the phytochemical corona as a programmable nano-bio interface. Green synthesis from Indian flora has potential that can yield coronas rich in flavonoids, polyphenols, terpenoids, and alkaloids. Each corona composition contributes to different physicochemical properties, such as cellular interactions and downstream effects on reactive oxygen species, endocytic uptake and signaling pathways (p53, AKT, MAPK). When in contact with biological fluids, the corona adsorbs host proteins, giving rise to a hybrid interface that further influences the therapeutic outcome. The corona composition directly contributes to the biological activities of these nanoparticles: for example, anticancer, antimicrobial, antioxidant, and antiparasitic. The corona offers intrinsic targeting, stimuli-responsive release and improved stability for drug delivery. Toxicity and safety assessment shows dose-dependent effects, organ accumulation and long-term concerns for which standardized testing is needed. Translational challenges include: reproducibility, seasonal and geographic phytochemical variation, variability in extraction methods, scalability, shelf life and regulatory ambiguity. Future directions include Artificial intelligence (AI)-driven phytosynthesis, precision nanomedicine, nano-bio interface engineering, multi-omics integration, exploration of endangered Indian flora, and digital twin modeling. This review provides a roadmap for engineering phytochemical coronas as precision nanomedicine platforms by shifting the focus from core to corona and from empirical recipes to predictive design. It positions biogenic nanoparticles not only as eco-friendly alternatives, but as programmable, superior therapeutics for cancer and drug-resistant infections.