Targeting Ultrasmall Gold Nanoparticles with cRGD Peptide Increases the Uptake and Efficacy of Cytotoxic Payload.

Cyclic arginyl-glycyl-aspartic acid peptide (cRGD) peptides show a high affinity towards αVβ3 integrin, a receptor overexpressed in many cancers. We aimed to combine the versatility of ultrasmall gold nanoparticles (usGNP) with the target selectivity of cRGD peptide for the directed delivery of a cytotoxic payload in a novel design. usGNPs were synthesized with a modified Brust-Schiffrin method and functionalized via amide coupling and ligand exchange and their uptake, intracellular trafficking, and toxicity were characterized.

Absolute Quantification of Gold Nanoparticles with Femtomolar Accuracy Using Inductively Coupled Plasma Atomic Emission Spectroscopy.

Here we describe a label-free method for the detection and absolute quantification of gold nanoparticles (AuNPs). Inductively coupled plasma atomic emission spectroscopy (ICP-AES) is used to detect less than a nanogram of AuNPs from complex unpurified biological samples. This corresponds to approximately femtomolar concentration range of AuNPs.