Quantitative measurement of nano/micro particle endocytosis with cell mass spectrometry

摘要

Methods for detecting the presence of nanoparticles or microparticles by cell mass spectrometry (CMS) are provided. CMS methods are provided for determining the number of nanoparticles or microparticles in each cell. Nanoparticles whose intracellular concentration can be determines by the CMS methods of the invention include polymeric nanoparticles (NPs), liposomes, viral-based NPs, carbon nanotubes, diamond NPs, polymeric micelles, nanocarriers, liposomes, and viral nanoparticles. Determination of the efficiency of drug delivery and intracellular titer of pathogens according to the invention is disclosed. Methods for determining intracellular uptake of virus particles are provided.

主权项

1. A method for quantifying a number of nanoparticles taken up by an individual cell, the method comprising the steps of:
(a) contacting a cell with a nanoparticle of dimension less than 1 μm, under conditions suitable for uptake of the nanoparticle by the cell, and incubating for a specific period of time; (b) recording a mass spectrum of the cell by cell mass spectrometry, wherein the process of cell mass spectrometry comprises: mounting and desorbing/vaporizing the cell into a gas phase; enhancing the number of charges on the cell; measuring a mass to charge (m/z) ratio by a mass analyzer; and measuring the total number of charges (z) on the cell by a charge detector coupled to the mass analyzer; (c) measuring a mass/charge (m/z) ratio of the cell contacted with the nanoparticle and a mass/charge (m/z) ratio of a corresponding cell not contacted with the nanoparticle; (d) measuring an absolute mass of each cell with an uptake of nanoparticles from the acquired values of m/z and the corresponding charge (z) on the cell, wherein the cell with an uptake of the nanoparticles shows an upward shift in m/z ratio; and (e) measuring the number of nanoparticles taken up by the individual cell within the specific period of time from a mean mass difference, wherein a mass difference corresponding to a known number of the nanoparticle of a known dimension is predetermined as a standard.