Multiplexed Screening of Cellular Uptake of Gold Nanoparticles Using Laser Desorption/Ionization Mass Spectrometry

Gold nanoparticles (AuNPs) are highly promising candidates as drug delivery agents into cells of interest. We describe for the first time the multiplexed analysis of nanoparticle uptake by cells using mass spectrometry. We demonstrate that the cellular uptake of functionalized gold nanoparticles with cationic or neutral surface ligands can be readily determined using laser desorption/ionization mass spectrometry of cell lysates. The surface ligands have “mass barcodes” that allow different nanoparticles to be simultaneously identified and quantified at levels as low as 30 pmol. Using this method, we find that subtle changes to AuNP surface functionalities can lead to measurable changes in cellular uptake propensities

Glycodendriproteins: a synthetic glycoprotein mimic enzyme with branched sugar-display potently inhibits bacterial aggregation.

The continuing ability of bacteria to resist current antibiotic treatments highlights the need for alternative strategies for inhibiting their pathogenicity. Bacterial attachment is a major factor in infectivity and virulence. This key binding phase of bacteria to any potential host is mediated by adhesin proteins and so these present an attractive therapeutic target for antiinfective blocking strategies. However, the natural ligands to adhesins are large, typically complex molecules that are difficult to mimic with small molecules. We describe here a method that creates precise synthetic mimics of glycoproteins that are designed to bind adhesins. By using protein-degrading enzymes as the basis for these mimics we have created large-molecule protein ligands that inhibit aggregation of pathogenic bacteria at levels greater than a million-fold higher than small-molecule inhibitors of adhesins