Endophyte-mediated biosynthesis of biogenic nanoparticles: mechanisms and biomedical applications.

Endophytes, the microorganisms inhabiting internal plant tissues without causing harm, have emerged as critical players at the intersection of biotechnology and nanoscience. Beyond their ecological functions, these are prolific producers of bioactive metabolites with antimicrobial, antioxidant, anticancer and stress-alleviating properties. Recent advances highlight their ability to act as natural bio-factories for the green synthesis of metallic, metal oxide, and carbon-based nanoparticles, where microbial metabolites mediate bio-reduction, capping, and stabilisation. This review offers a critical overview of research published in the past decade, identified through major scientific databases, highlighting key studies on endophyte-mediated nanoparticle synthesis, characterisation, and applications. Inclusion focused on peer-reviewed articles addressing biomedical, agricultural, and environmental applications, while descriptive reports lacking mechanistic or functional insight were excluded. Key findings reveal that endophyte-derived nanoparticles exhibit enhanced bioactivity, including potent antimicrobial effects against multidrug-resistant pathogens, targeted anticancer efficacy, and agricultural benefits such as improved nutrient uptake, pathogen resistance, and abiotic stress tolerance. However, major knowledge gaps persist regarding mechanistic pathways, phytotoxicity, long-term safety, and scalability. Comparative analysis with plant-mediated, bacterial-mediated and chemically synthesised further highlights the unique advantages of endophytes but also underscores the limited integration of omics-based insights and the absence of standardised protocols. By providing both a descriptive overview and a critical evaluation, this review advances understanding of endophyte-mediated nanotechnology as a sustainable platform for global health and food security. It emphasises the need for interdisciplinary research, regulatory clarity, and systematic toxicological evaluation to translate laboratory findings into real-world applications.