Abstract
Gold nanoparticles (AuNPs) are increasingly used in biomedical applications, hence understanding the processes that affect their biocompatibility and stability are of significant interest. In this study, we assessed the stability of peptide-capped AuNPs and used the embryonic zebrafish (Danio rerio) as a vertebrate system to investigate the impact of synthesis method and purity on their biocompatibility. Using glutathione (GSH) as a stabilizer, Au-GSH nanoparticles with identical core sizes were terminally modified with Tryptophan (Trp), Histidine (His) or Methionine (Met) amino acids and purified by either dialysis or ultracentrifugation. Au-GSH-(Trp)2 purified by dialysis elicited significant morbidity and mortality at 200 µg/mL, Au-GSH-(His)2 induced morbidity and mortality after purification by either method at 20 and 200 µg/mL, and Au-GSH-(Met)2 caused only sublethal responses at 200 µg/mL. Overall, toxicity was significantly reduced and ligand structure was improved by implementing ultracentrifugation purifications at several stages during the multi-step synthesis and surface modification of Au-GSH nanoparticles. When carefully synthesized at high purity, peptide-functionalized AuNPs showed high biocompatibility in biological systems.
Highlights
Gold nanoparticles (AuNPs) are largely employed in the nanotechnology field in a variety of applications, mainly for their structural, electronic, optical and catalytic properties [1]
Biocompatible amino acid functionalized Au-GSH NPs can be produced when ultracentrifugation is used as a purification technique at each stage of a multi-step synthesis
The water-solubility of stock solutions of Au-GSH-(X)2 (X = Trp, His, Met) at pH 8.0 indicate that the terminal amino acids are conjugated to GSH covalently attached to the NP surface
Summary
Gold nanoparticles (AuNPs) are largely employed in the nanotechnology field in a variety of applications, mainly for their structural, electronic, optical and catalytic properties [1]. There is a growing interest around improving the synthesis method and purity of AuNPs, those designed for medical applications [2,3]. The inherent optical resonance of AuNPs makes them especially useful in biomedical imaging applications [4]. The current study reports on the synthesis, uptake, and biocompatibility of spherical AuNPs with small peptide ligands as stabilizers designed for chelation and optical imaging applications. Surface chemistry has been shown to play a role in the uptake and toxicity of AuNPs and the surface affinity of AuNPs enables the use of a large variety of inorganic and organic molecules as stabilizing ligands [5,6,7]. Often used in excess during the synthesis process, free or unbound stabilizers can remain after synthesis, requiring removal to prevent impacts on the stability, purity, and reactivity of the resulting nanoparticles [9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
