title: Iron-based ferritin nanocore as a contrast agent.
abstract: Self-assembling protein cages have been exploited as templates for nanoparticle synthesis. The ferritin molecule, a protein cage present in most living systems, stores excess soluble ferrous iron in the form of an insoluble ferric complex within its cavity. Magnetic nanocores formed by loading excess iron within an engineered ferritin from Archaeoglobus fulgidus (AfFtn-AA) were studied as a potential magnetic resonance (MR) imaging contrast agent. The self-assembly characteristics of the AfFtn-AA were investigated using dynamic light scattering technique and size exclusion chromatography. Homogeneous size distribution of the assembled nanoparticles was observed using transmission electron microscopy. The magnetic properties of iron-loaded AfFtn-AA were studied using vibrating sample magnetometry. Images obtained from a 3.0 T whole-body MRI scanner showed significant brightening of T(1) images and signal loss of T(2) images with increased concentrations of iron-loaded AfFtn-AA. The analysis of the MR image intensities showed extremely high R(2) values (5300 mM(-1) s(-1)) for the iron-loaded AfFtn-AA confirming its potential as a T(2) contrast agent.
authors.affiliation: Division of Bioengineering, School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637457.
authors.forename: Barindra
authors.initials: B
authors.lastname: Sana
authors.forename: Eric
authors.initials: E
authors.lastname: Johnson
authors.forename: Kenneth
authors.initials: K
authors.lastname: Sheah
authors.forename: Chueh Loo
authors.initials: CL
authors.lastname: Poh
authors.forename: Sierin
authors.initials: S
authors.lastname: Lim
mesh_terms: D019611:Archaeoglobus fulgidus / Q000201:enzymology*; D003287:Contrast Media / Q000378:metabolism*; D005293:Ferritins / Q000302:isolation & purification / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000379:methods; D053758:Nanoparticles; D029595:Orchidaceae
chemical_list: D003287:Contrast Media; D005293:Ferritins; D007501:Iron