Transport of Gold Nanoparticles by Vascular Endothelium from Different Human Tissues

PLoS One. 2016 Aug 25;11(8):e0161610. doi: 10.1371/journal.pone.0161610. eCollection 2016.

Abstract

The selective entry of nanoparticles into target tissues is the key factor which determines their tissue distribution. Entry is primarily controlled by microvascular endothelial cells, which have tissue-specific properties. This study investigated the cellular properties involved in selective transport of gold nanoparticles (<5 nm) coated with PEG-amine/galactose in two different human vascular endothelia. Kidney endothelium (ciGENC) showed higher uptake of these nanoparticles than brain endothelium (hCMEC/D3), reflecting their biodistribution in vivo. Nanoparticle uptake and subcellular localisation was quantified by transmission electron microscopy. The rate of internalisation was approximately 4x higher in kidney endothelium than brain endothelium. Vesicular endocytosis was approximately 4x greater than cytosolic uptake in both cell types, and endocytosis was blocked by metabolic inhibition, whereas cytosolic uptake was energy-independent. The cellular basis for the different rates of internalisation was investigated. Morphologically, both endothelia had similar profiles of vesicles and cell volumes. However, the rate of endocytosis was higher in kidney endothelium. Moreover, the glycocalyces of the endothelia differed, as determined by lectin-binding, and partial removal of the glycocalyx reduced nanoparticle uptake by kidney endothelium, but not brain endothelium. This study identifies tissue-specific properties of vascular endothelium that affects their interaction with nanoparticles and rate of transport.

MeSH terms

  • Animals
  • Biological Transport
  • Brain / metabolism
  • Cytosol / metabolism
  • Endocytosis
  • Endothelial Cells / metabolism
  • Endothelium, Vascular / drug effects*
  • Gold / chemistry*
  • Humans
  • Kidney / metabolism
  • Male
  • Metal Nanoparticles / chemistry*
  • Microscopy, Electron, Transmission
  • Polyethylene Glycols / chemistry
  • Polysaccharides / chemistry
  • Rats
  • Rats, Wistar
  • Tissue Distribution

Substances

  • Polysaccharides
  • Polyethylene Glycols
  • Gold

Grants and funding

This work was supported by Sheffield Teaching Hospitals Trust and the Biotechnology and Biological Sciences Research Council (BB/K009184/1). The funders provided support in the form of salaries for authors (RG, IAR) and consumables, but did not have any role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. Midatech Pharma plc provided nanoparticles and facilities for ICP mass spectrometry. The specific roles of the authors are articulated in the ‘author contributions’ section.