Magnetoferritin enhances T2 contrast in magnetic resonance imaging of macrophages

Ambrish Kumar, Vikas Nandwana, Soo Ryoon Ryoo, Samyukta Ravishankar, Bhargy Sharma, Konstantin Pervushin, Vinayak P. Dravid, Sierin Lim*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


Imaging of immune cells has wide implications in understanding disease progression and staging. While optical imaging is limited in penetration depth due to light properties, magnetic resonance (MR) imaging provides a more powerful tool for the imaging of deep tissues where immune cells reside. Due to poor MR signal to noise ratio, tracking of such cells typically requires contrast agents. This report presents an in-depth physical characterization and application of archaeal magnetoferritin for MR imaging of macrophages – an important component of the innate immune system that is the first line of defense and first responder in acute inflammation. Magnetoferritin is synthesized by loading iron in apoferritin in anaerobic condition at 65 °C. The loading method results in one order of magnitude enhancement of r1 and r2 relaxivities compared to standard ferritin synthesized by aerobic loading of iron at room temperature. Detailed characterizations of the magnetoferritin revealed a crystalline core structure that is distinct from previously reported ones indicating magnetite form. The magnetite core is more stable in the presence of reducing agents and has higher peroxidase-like activities compared to the core in standard loading. Co-incubation of macrophage cells with magnetoferritin in-vitro shows significantly higher enhancement in T2-MRI contrast of the immune cells compared to standard ferritin.

Original languageEnglish (US)
Article number112282
JournalMaterials Science and Engineering C
StatePublished - Sep 2021


  • Immune imaging
  • Iron oxide nanoparticle
  • MRI
  • Magnetoferritin
  • Protein cage

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering


Dive into the research topics of 'Magnetoferritin enhances T2 contrast in magnetic resonance imaging of macrophages'. Together they form a unique fingerprint.

Cite this