Molecular imaging with nanoparticles: giant roles for dwarf actors

Histochem Cell Biol. 2008 Nov;130(5):845-75. doi: 10.1007/s00418-008-0511-y. Epub 2008 Sep 30.


Molecular imaging, first developed to localise antigens in light microscopy, now encompasses all imaging modalities including those used in clinical care: optical imaging, nuclear medical imaging, ultrasound imaging, CT, MRI, and photoacoustic imaging. Molecular imaging always requires accumulation of contrast agent in the target site, often achieved most efficiently by steering nanoparticles containing contrast agent into the target. This entails accessing target molecules hidden behind tissue barriers, necessitating the use of targeting groups. For imaging modalities with low sensitivity, nanoparticles bearing multiple contrast groups provide signal amplification. The same nanoparticles can in principle deliver both contrast medium and drug, allowing monitoring of biodistribution and therapeutic activity simultaneously (theranostics). Nanoparticles with multiple bioadhesive sites for target recognition and binding will be larger than 20 nm diameter. They share functionalities with many subcellular organelles (ribosomes, proteasomes, ion channels, and transport vesicles) and are of similar sizes. The materials used to synthesise nanoparticles include natural proteins and polymers, artificial polymers, dendrimers, fullerenes and other carbon-based structures, lipid-water micelles, viral capsids, metals, metal oxides, and ceramics. Signal generators incorporated into nanoparticles include iron oxide, gadolinium, fluorine, iodine, bismuth, radionuclides, quantum dots, and metal nanoclusters. Diagnostic imaging applications, now appearing, include sentinal node localisation and stem cell tracking.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Acoustics
  • Animals
  • Contrast Media* / chemistry
  • Contrast Media* / pharmacokinetics
  • Contrast Media* / toxicity
  • Diagnostic Imaging / methods*
  • Humans
  • Image Interpretation, Computer-Assisted
  • Magnetic Resonance Imaging
  • Microscopy
  • Nanomedicine*
  • Nanoparticles*
  • Optics and Photonics
  • Particle Size
  • Positron-Emission Tomography
  • Radiography
  • Surface Properties
  • Tomography, Emission-Computed, Single-Photon
  • Tomography, X-Ray Computed
  • Ultrasonography


  • Contrast Media