title: Determination of the intracellular stability of gold nanoparticle monolayers using mass spectrometry.
abstract: Monolayer stability of core-shell nanoparticles is a key determinant of their utility in biological studies such as imaging and drug delivery. Intracellular thiols (e.g., cysteine, cysteamine, and glutathione) can trigger the release of thiolate-bound monolayers from nanoparticles, a favorable outcome for controllable drug release applications but an unfavorable outcome for imaging agents. Here, we describe a method to quantify the monolayer release of gold nanoparticles (AuNPs) in living cells using parallel measurements by laser desorption/ionization (LDI) and inductively coupled plasma (ICP) mass spectrometry. This combination of methods is tested using AuNPs with structural features known to influence monolayer stability and on cells types with varying concentrations of glutathione. On the basis of our results, we predict that this approach should help efforts to engineer nanoparticle surface monolayers with tunable stability, providing stable platforms for imaging agents and controlled release of therapeutic monolayer payloads.
authors.affiliation: Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, United States.
authors.forename: Zheng-Jiang
authors.initials: ZJ
authors.lastname: Zhu
authors.forename: Rui
authors.initials: R
authors.lastname: Tang
authors.forename: Yi-Cheun
authors.initials: YC
authors.lastname: Yeh
authors.forename: Oscar R
authors.initials: OR
authors.lastname: Miranda
authors.forename: Vincent M
authors.initials: VM
authors.lastname: Rotello
authors.forename: Richard W
authors.initials: RW
authors.lastname: Vachet
mesh_terms: D005978:Glutathione / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D006367:HeLa Cells; D056945:Hep G2 Cells; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D053768:Metal Nanoparticles / Q000032:analysis*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013438:Sulfhydryl Compounds / Q000737:chemistry
chemical_list: D013438:Sulfhydryl Compounds; D006046:Gold; D005978:Glutathione