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, selfassembly 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.

Intratumoral generation of photothermal gold nanoparticles through a vectorized biomineralization of ionic gold

“…Further to this, if cellular machinery are used to generate gold nanoparticles, the resulting plasmon-optical properties could act as a reporter of the affecting cell phenotype. This capability to generate gold nanoparticles via cellular biomolecules has already been demonstrated previously in mammalian cells [36][37][38][39][40][41][42][43][44][45][46][47] . The precise mechanism for this cellular bioreduction of gold nanoparticles is not fully understood, however, these treatments have been known to negatively impact cell health through cellular responses via shock and stress-related proteins 42 , decrease in viability 43,44 , and even cell fixation 44 .…”

ToF-SIMS 3D imaging unveils important insights on the cellular microenvironment during biomineralization of gold nanostructures

“…In recent reports, molecular modeling and simulation studies indicate that Au binding polypeptides interact with Au + nuclear lattices and exhibit specific sequence repeats, forming parallel and antiparallel β-sheet structures 8,14 . Threonine and serine polar side chains causes close contact between Au crystal planes and the peptide, which then rearranges the amino acid -OH groups into a regular lattice 6 .…”

“…The presynthesized spherical NPs act as solder between triangular microplates, converting them into long nanoribbons 5 . Such nanoribbons act as a wave guide and facilitate faster propagation of Plasmon waves for photothermal therapy 5,8,9 . Starting from a large field of view of 500 × 500 µm, we focused on a smaller ROI of 120 × 120 µm where the cell membrane interacts with the nanoribbons as shown in Fig.…”

Crafting Polymeric and Peptidic Hydrogels for Improved Wound Healing

“…Their modular chemical design, biocompatibility, and thixotropic nature make MDPs a viable injectable hydrogel system for direct delivery to the wound site ( Figure ) . The biological and chemical behavior of the hydrogel can be tuned by substituting different amino acids on the peptide chain of the MDP . NIH‐3T3 fibroblasts were seeded in the MDP hydrogel for 3, 7, 10, and 14 days.…”