(658f) Biologically Inspired Stealth Peptide-Coated Gold Nanoparticles

Nanoparticle-based biotechnology is relevant to many biomedical applications including drug delivery, diagnosis, and biosensing. A challenge to these applications is nonspecific protein adsorption, which can result in cellular uptake, nanoparticle aggregation, or an immune system response. Proteins in the human body are well adapted to resist nonspecific adsorption and display stability in complex media. Through examining the surfaces of proteins we can seek inspiration for designing novel biocompatible materials with these properties. The analysis of over one thousand human proteins indicates that glutamic acid (E) and lysine (K) are the two most prevalent amino acids on the surfaces of proteins. Based on this knowledge, a stealth peptide was designed by alternating negatively charged E and positively charged K amino acid residues. This EK stealth peptide was incorporated into a gold nanoparticle system exhibiting high resistance to nonspecific protein adsorption. This system displays stability in salt, protein, and undiluted human blood serum. In addition, the peptide sequence can be extended with a functional peptide sequence to achieve specific targeting without the need for bioconjugation. Particles lacking specific targeting moieties possess stealth properties, whereas particles containing specific targeting moieties (c(RGDf)) are specifically uptaken by cells. This talk will discuss the design, assembly conditions, characterization, stability, and versatility of the peptide-based gold nanoparticle system.