Elucidating The Antimicrobial and Cytotoxic Responses of Silver Nanoparticle Synthesised Using Pongamia Pinnata Leaf Extract

Abstract

Biosynthesized nanoparticles, for their unique additional properties, have received global attention in nanomedicine [1]. Medicinal plants have extensively been screened for ecofriendly and efficient synthesis of metal nanoparticles [2]. Owing to the ever increasing applications of biosynthesized metal nanoparticles, the manuscript demonstrates the biogenic synthesis of silver nanoparticle (AgNP) using Pongamia pinnata leave extract. The characterization of biosynthesized AgNP indicated the highest yield of approximate 25 nm size face centred cubic silver nanocrystal with negative surface potential was obtained, when the plant extract taken in ten folds excess to metal salts. The biological corona, included bioactive molecules from the plant leave extract, is stabilising the AgNP core, as confirmed by elemental mapping of the nanoparticle. The biosynthesised AgNP found to have antimicrobial activity against Escherichia coli and Staphylococcus aureus, via predominantly enhanced intracellular ROS generation, at very low concentration. Interestingly, the nanoparticle showed higher cytotoxicity towards fibrosarcoma (HT1080) cells than differentiated monocytes (dTHP1), and also found to co-localise with nucleic acid. Additionally, the concentration inhibiting the microbial growth is found to be significantly higher than the cytotoxic concentration against HT1080 cell. The work will further be extended towards optimizing medicinal nanoformulations using these nanoparticles, and will be assessed for different therapeutic applications.