Biogenic synthesis of silver nanoparticles using extracts of Leptolyngbya JSC-1 that induce apoptosis in HeLa cell line and exterminate pathogenic bacteria

Utilizing novel approaches for the green synthesis of metal nanoparticles are of great importance. Therefore, we reported biogenic synthesis of silver nanoparticles (AgNPs) using extracts of Leptolyngbya strain JSC-1, and their significant applications against pathogenic bacteria and cancerous HeLa cell line. The biofabricated AgNPs were characterized by UV-visible spectroscopy, FTIR, SEM, TEM, DLS and zeta-potential. The as prepared AgNPs were assessed for inhibition of bacterial growth and induction of apoptosis in HeLa cells by different doses of AgNPs was evaluated. UV-visible spectroscopy and FTIR of AgNPs demonstrated the surface plasmon resonance at 413 nm and interaction among extract and nanoparticles, respectively. Electron microscopy revealed the morphology and DLS demonstrated size distribution of the particles (10-100 nm). Zeta potential values were between -47 and 0 mV, indicating stability of the particles. Proliferation of HeLa cells was significantly inhibited and severe cytotoxicity with higher intracellular uptake were observed after applying high concentration of AgNPs. Efficient inhibition zones (17 ± 2 and 21 ± 2 mm) were produced at maximum concentration (100 µl from 1 mg ml^-1 stock of AgNPs) for Staphylococcus aureus and Escherichia coli, respectively. These findings reveal that the biofabricated AgNPs possess strong antibacterial activity and ability to induce apoptosis in cancer cell line (HeLa).