title: Polyelectrolyte coating of iron oxide nanoparticles for MRI-based cell tracking.
abstract: Iron oxide-based magnetic nanoparticles (MNPs) offer unique properties for cell tracking by magnetic resonance imaging (MRI) in cellular immunotherapy. In this study, we investigated the uptake of chemically engineered NPs into antigen-presenting dendritic cells (DCs). DCs are expected to perceive MNPs as foreign antigens, thus exhibiting the capability to immunologically sense MNP surface chemistry. To systematically evaluate cellular uptake and T2/T2(⁎) MR imaging properties of MNPs, we synthesized polymer-based MNPs by employing layer-by-layer (LbL) technology. Thereby, we achieved modification of particle shell parameters, such as size, surface charge, and chemistry. We found that subcellular packaging of MNPs rather than MNP content in DCs influences MR imaging quality. Increased local intracellular electron density as inferred from transmission electron microscopy (TEM) strongly correlated with enhanced contrast in MRI. Thus, LbL-tailoring of MNP shells using polyelectrolytes that impact on uptake and subcellular localization can be used for modulating MR imaging properties.
  
  
  BACKGROUND
  In this study, layer-by-layer tailoring of magnetic NP shells was performed using polyelectrolytes to improve uptake by dendritic cells for cell-specific MR imaging. The authors conclude that polyelectrolyte modified NP-s can be used for modulating improving MR imaging quality by increasing subcellular localization.
authors: Institute for Biomedical Engineering, Department of Cell Biology, University Hospital RWTH Aachen University, Aachen, Germany.
authors: Sebastian
authors: S
authors: Schwarz
authors: John E
authors: JE
authors: Wong
authors: Joerg
authors: J
authors: Bornemann
authors: Michael
authors: M
authors: Hodenius
authors: Uwe
authors: U
authors: Himmelreich
authors: Walter
authors: W
authors: Richtering
authors: Mathias
authors: M
authors: Hoehn
authors: Martin
authors: M
authors: Zenke
authors: Thomas
authors: T
authors: Hieronymus
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D058948:Cell Tracking; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000166:cytology*; D005290:Ferric Compounds / Q000737:chemistry*; D006412:Hematopoietic Stem Cells / Q000166:cytology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles / Q000008:administration & dosage / Q000737:chemistry; D051379:Mice; D046529:Microscopy, Electron, Transmission; D013194:Staining and Labeling
chemical_list: D005290:Ferric Compounds; D058185:Magnetite Nanoparticles; C000499:ferric oxide