Biogenic metallic nanoparticles as multifunctional theranostic platforms for targeted drug delivery and imaging

The biogenic synthesis of nanoparticles represents a fascinating intersection of green chemistry and medical technology. This methodology harnesses plants’ rich biochemical repertoire to facilitate the development of biocompatible nanostructures. Biogenic metallic nanoparticles (BGMNPs) have gained significant interest due to their utility in therapeutic applications. Biogenic synthesis offers numerous advantages, as it is eco-friendly and possesses unique physicochemical properties, i.e., intrinsic biocompatibility, low toxicity, and feasible, cost-effective synthesis. Comparative insights reveal that BGMNPs have superior antioxidant, anticancer, and antimicrobial activities, along with improved imaging efficacy in MRI, fluorescence, and plasmonic modalities. This article summarises the available knowledge on biogenic metal-based nanoparticles as drug delivery agents. Additionally, it underscores the potential of BGMNPs, detailing their action in diseases such as cancer, inflammation, and microbial infections, as well as the toxicity and challenges, briefly, including cellular uptake, mechanisms of cell interaction and internalisation, reactive oxygen species formation, inflammatory responses, and the complex interplay of pathways governing their behaviour at a molecular level. By summarising biological actions, molecular targets, and drug delivery imaging, this work provides a consolidated perspective on the translational potential of green nanotechnology in next-generation theranostics.