Anisotropic gold nanostructures: optimization via in silico modeling for hyperthermia

Abstract

Protein- and peptide-based manufacturing of self-assembled supramolecular functional materials has been a formidable challenge for biomedical applications, being complex in structure and immunogenic in nature. In this context, self assembly of short amino acid sequences as simplified building blocks to design metal-biomolecule frameworks (MBioFs) is an emerging field of research. Here, we report a facile, bioinspired route of anisotropic nanostructure synthesis using gold binding peptides (10-15mers) secreted by cancer cells. The bioinformatics tool i-TASSER predicts the effect of amino acid sequences on metal binding sites and the secondary structures of the respective peptide sequence. Electron microscopy, X-ray, infrared, and Raman spectroscopy validated the versatile anisotropic gold nanostructures and the metal-bioorganic nature of this biomineralization. We studied the influence of precursor salt, pH, and peptide concentration on the evolution of nanoleaf, nanoflower, nanofiber, and dendrimer-like anisotropic MBioFs. Characterization of photothermal properties using infrared laser (785 nm) revealed excellent conversion of light into heat. Exposure of bacterial cells in culture exhibits high rate of photothermal death using lower laser power (1.9 W/cm(2)) compared with recent reports. The MBioF's self-assembly process shown here can readily be extended and adapted to superior plasmonic material synthesis with a promising photothermal effect for in vivo biofilm destruction and cancer hyperthermia applications.