Bioinspired Synthesis and Characterization of Dual-Function Zinc Oxide Nanoparticles from Saccharopolyspora hirsuta: Exploring Antimicrobial and Anticancer Activities

Abstract

Microbial synthesis offers a sustainable and eco-friendly approach for nanoparticle production. This study explores the biogenic synthesis of zinc oxide nanoparticles (ZnO-NPs) utilizing the actinomycete <i>Saccharopolyspora hirsuta</i> (Ess_amA6) isolated from <i>Tapinoma simrothi</i>. The biosynthesized ZnO-NPs were characterized using various techniques to confirm their formation and properties. UV-visible spectroscopy revealed a characteristic peak at 372 nm, indicative of ZnO-NPs. X-ray diffraction (XRD) analysis confirmed the crystalline structure of the ZnO-NPs as hexagonal wurtzite with a crystallite size of approximately 37.5 ± 13.60 nm. Transmission electron microscopy (TEM) analysis showed the presence of both spherical and roughly hexagonal ZnO nanoparticles in an agglomerated state with a diameter of approximately 44 nm. The biogenic ZnO-NPs exhibited promising biomedical potential. They demonstrated selective cytotoxic activity against human cancer cell lines, demonstrating higher efficacy against Hep-2 cells (IC50 = 73.01 µg/mL) compared to MCF-7 cells (IC50 = 112.74 µg/mL). Furthermore, the biosynthesized ZnO-NPs displayed broad-spectrum antimicrobial activity against both <i>Pseudomonas aeruginosa</i> and <i>Staphylococcus aureus</i> with clear zones of inhibition of 12.67 mm and 14.33 mm, respectively. The MIC and MBC values against <i>P. aeruginosa</i> and <i>S. aureus</i> ranged between 12.5 and 50 µg/mL. These findings suggest the potential of <i>S. hirsuta</i>-mediated ZnO-NPs as promising biocompatible nanomaterials with dual applications as antimicrobial and anticancer agents.