There is an interest in gaining more insight into how the physico-chemical properties of a nanoparticle influence it’s behavior in vivo. Inorganic nanoparticles are studied as tools for (bio)imaging purposes as well as a therapeutic agent. These nanoparticles typically have an organic surface coating which determines it’s behavior. Gold nanoparticles (GNP) are stabilized using small molecules (e.g. citrate), lipids (e.g. CTAB) and polymers like PEG. Unfortunately many of these cannot be used in vivo due to lack of colloidal stability or their inherent toxicity. Therefore, we set out to look for new ways to stabilize these nanoparticles. Peptides can provide a solution. It was proven that peptide-capped gold nanoparticles are highly stable (resistant against 1,5M NaCl) without loss in colloidal stability. The key idea lies in self-assembly of peptide chains on the gold surface once the covalent bond between the thiol group of Cys and gold is established. Even when complete coverage with peptides is not possible, 5-25% is sufficient to yield peptide-capped gold nanoparticles with remarkable properties. The efficiency of peptide self-assembly on the surface obviously depends on the length of a peptide, its composition and the adopted secondary structure. It was shown that oligopeptides like CALNN are effective in stabilizing gold particles up 30 nm in diameter under physiological conditions. However larger GNPs cannot be stabilized with these oligopeptides. Therefore we designed new peptide sequences and peptide amphiphiles able to stabilize gold nanoparticles over a large size range facilitating their use in biomedical applications.

One peptide for them all? Stabilization of gold nanoparticles of different sizes by a common peptide amphiphile

2019 Fall National Meeting

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