Peptide-Induced Biomineralization of Tin Oxide (SnO2) Nanoparticles for Antibacterial Applications

Recently, there has been growing attention and effort to search for new microbicidal drugs which present different mode of action from those already existing, as an alternative to the global threat of fungal and bacterial multi drug resistance (MDR). Here we propose biological synthesis of SnO2 nanoparticles using mammalian cells as an economic and ecofriendly platform. This presents a novel biogenic method for SnO2 synthesis using metal binding peptides extracted from MCF-7 human cancer cells, which induces the biornineralization of SnO2 nanoparticles. A series of electron donor functional groups and metal binding sites in these peptides reacts with Sn2+ ions and directs the growth of SnO2 nanoparticles without addition of toxic redox and capping agents in the reaction system. Since peptides present reactive sites in aqueous solution at room temperature, a facile reaction environment can be easily achieved. Furthermore, by tuning the reactants' concentration and pH, the size, shape and 3D-structures of SnO2 nanoparticles can be controlled. Peptides also ensure biocompatibility, and SnO2 nanoparticles provide antibacterial properties, which broadens their applications in biomedical fields.