Synthesis of gallotannin capped iron oxide nanoparticles and their broad spectrum biological applications

Abstract

Green synthesized nanoparticles (NPs) have attracted enormous attention for their clinical and non-clinical applications. A natural polyphenol, gallo-tannin (GT) was used to reduce and cap the Fe2O3-NPs. GT-Fe2O3-NPs were synthesized following co-precipitation of FeCl3and FeSO4·7H2O with GT. Fe2O3-NPs absorbed light at 380 nm. Physicochemically, Fe2O3-NPs were spherical with slight aggregation and average diameter of 12.85 nm. X-ray diffraction confirmed crystallinity and EDX revealed the elemental percentage of iron and oxygen as 21.7% and 42.11%, respectively. FT-IR data confirmed the adsorption of gallo-tannin functional groups. Multiple drug-resistant (MDR)Escherichia coli(ESβL),Pseudomonas aeruginosa(ESβL), andStaphylococcus aureuswere found susceptible to 500-1000 μg GT-Fe2O3-NPs per ml. In synergy, Fe2O3-NPs enhanced the efficiency of some antibiotics. GT-Fe2O3NPs showed significant (P≤ 0.05) inhibition of growth and biofilm against MDRE. coli,P. aeruginosa, andS. aureuscausing morphological and biofilm destruction. Violacein production (quorum sensing mediated) byC. violaceumwas inhibited by GT-Fe2O3-NPs in a concentration-dependent manner with a maximum decrease of 3.1-fold. A decrease of 11-fold and 2.32-fold in fungal mycelial growth and human breast cancer (MCF-7) cell viability, respectively was evident. This study suggests a plausible role of gallo-tannin capped Fe2O3-NPs as an alternative antibacterial, antiquorum sensing, antibiofilm, antifungal, and anti-proliferative agent.