Green synthesis of bovine serum albumin–tailored silver nanoparticles from Aspergillus fumigatus: Statistical optimization, characterization, antioxidant, and cytotoxicity evaluation on colon cancer cells

Abstract

Nanobiotechnology has evolved as a promising technology in developing therapeutically active materials. This study involved the biological synthesis of silver nanoparticles (AgNPs) from extracellular filtrate from the fungal species Aspergillus fumigatus to assess their antioxidant and cytotoxic activity under in‐vitro conditions. This method has become more reliable than physical and chemical approaches, attributed to its use of ecologically clean and non‐toxic methods. These synthesized nanoparticles are then characterized by UV–visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), dynamic light scattering, scanning electron microscope (SEM), differential scanning calorimetry, and X‐ray diffraction (XRD). Design optimization was done to optimize the selected variables to choose the best‐fit ratios for the experiment. UV spectroscopy showed the absorption peaks for AgNPs and bovine serum albumin (BSA) AgNPs at 300 and 315 nm. FTIR spectroscopy showed amide, carboxyl, and ester groups in BSA AgNPs, indicating their role in stabilizing nanoparticles. The particle size and zeta potential for AgNPs and BSA AgNPs were found to be 124.81 and 152.92 nm; zeta potentials for AgNPS and BSA AgNPs were found to be −13.3 and −15.6 mV. Various antioxidant studies like 2,2‐Diphenyl‐1‐picrylhydrazyl (DPPH), 2,2‐azinobis‐(3‐ethylbenzothiazoline‐6‐sulfonate) (ABTS), ion chelating assay, lipid peroxide assay, and malondialdehyde were carried out, indicating good antioxidant activity for synthesized nanoparticles. SEM images advocated good spherical images and are well dispersed. The cytotoxic assay performed on HT‐29 colon cancer cells exhibited good inhibition activity for AgNPs and BSA AgNPs, with an IC50 value of 120 and 100 μg/ml. These study results revealed that the synthesized AgNPs, on optimization through Box‐Behnken design, exhibited good antioxidant and cytotoxic activity.