Dual Mass Spectrometric Tissue Imaging of Nanocarrier Distributions and Their Biochemical Effects

Anal Chem. 2020 Jan 21;92(2):2011-2018. doi: 10.1021/acs.analchem.9b04398. Epub 2019 Dec 30.

Abstract

Nanomaterial-based drug delivery vehicles are able to deliver therapeutics in a controlled, targeted manner. Currently, however, there are limited analytical methods that can detect both nanomaterial distributions and their biochemical effects concurrently. In this study, we demonstrate that matrix assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) and laser ablation inductively coupled plasma mass spectrometry imaging (LA-ICP-MSI) can be used together to obtain nanomaterial distributions and biochemical consequences. These studies employ nanoparticle-stabilized capsules (NPSCs) loaded with siRNA as a testbed. MALDI-MSI experiments on spleen tissues from intravenously injected mice indicate that NPSCs loaded with anti-TNF-α siRNA cause changes to the lipid composition in white pulp regions of the spleen, as anticipated, based on pathways known to be affected by TNF-α, whereas NPSCs loaded with scrambled siRNA do not cause the predicted changes. Interestingly, LA-ICP-MSI experiments reveal that the NPSCs primarily localize in the red pulp, suggesting that the observed changes in lipid composition are due to diffusive rather than localized effects on TNF-α production. Such information is only accessible by combining data from the two modalities, which we accomplish by using the heme signals from MALDI-MSI and iron signals from LA-ICP-MSI to overlay the images. Several unexpected changes in lipid composition also occur in regions where the NPSCs are found, suggesting that the NPSCs themselves can influence tissue biochemistry as well.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Capsules / administration & dosage
  • Capsules / analysis*
  • Capsules / metabolism
  • Drug Carriers / administration & dosage
  • Drug Carriers / analysis
  • Drug Carriers / metabolism
  • Injections, Intravenous
  • Mass Spectrometry
  • Mice
  • Nanoparticles / administration & dosage
  • Nanoparticles / analysis*
  • Nanoparticles / metabolism
  • Spleen / chemistry*
  • Spleen / metabolism
  • Tissue Distribution

Substances

  • Capsules
  • Drug Carriers