Magnetic iron oxide nanoparticles
for MR contrast agents


Introduction

Why magnetic nanoparticles?
- Superparamagnetism

How SPIO works as MRI contrast agents?

Commercialized SPIO MRI contrast agents

In vivo detection of biological targets

References

In vivo detection of biological targets

  • Case 1: Magnetic iron oxide nanoparticles are conjugated with a cancer-targeting antibody, Herceptin, and intravenously injected into a mouse with a small HER2/neu positive cancer. They selectively detect small cancer with strong MR signals shown as blue color, which represents high MR relaxivity. [1,2,3]
  • Case 2: Gene transfection was demonstrated using MRI. Tumor cells were engineered to overexpress the transferrin receptor (a cell membrane receptor involved in regulating cellular iron uptake). As a result the tumor overexpressing transferrin receptors accumulated iron in the form of MIONs (monocrystalline iron oxide nanoparticles). The MIONs induce a high susceptibility (the left-hand tumor in these animals – the control tumor is on the right flank) imaged as signal loss by MR. [6,7]
  • Case 3: SPIO particles coated with dextran are sequestered by phagocytic Kupffer cells in normal RES, but are not retained in tumor tissue. Consequently, there are significant differences in T2 relaxation between normal RES tissue and tumors increasing the detectability of hepatic metastases.[8]

 

created by Yoon Kyung Kim

Clinical Medicine:
BME240