Authors: G. Wang, M.R. Papasani, P.J. Hrdlicka, R.A. Hill
Affilation: University of Idaho, United States
Pages: 304 - 307
Keywords: gold nanoparticles, peptide, serum proteins
Gold nanoparticles (Au NPs) have been widely investigated as promising nanocarriers for therapeutics and other biologically active molecules. In the present study, two different cysteine-terminated peptides were used to form nanoconjugates with Au NPs (20 nm). Free peptide A can enter cells through receptor-mediated endocytosis, while free peptide B is a negative control with no known cell binding activity. We investigated the interactions of serum proteins with gold-peptide nanoconjugates and the cellular uptake of the nanoconjugates in the presence and absence of serum proteins. Electrophoresis gel data indicated the association of serum proteins with the nanoconjugates. In the presence and absence of serum in cell culture medium, both fluorophore-labeled peptide A and peptide B gold nanoconjugates were internalized by cells. Following cell internalization, at least some nanoconjugates were dissociated, as free peptides were detected using fluorescence microscopy. These data suggest that upon the adsorption of serum proteins, the cellular uptake of gold-peptide nanoconjugates may be mediated via multiple mechanisms including specific receptor-mediated uptake (via peptide ligands), adsorbed serum protein interactions with cell receptors and non–specific mechanisms. The interactions of these pathways resulted in different sub-cellular localization and distribution of the nanoconjugates.