Poly(amino acid)s micelle-mediated assembly of magnetite nanoparticles for ultra-sensitive long-term MR imaging of tumors.

Micelles composed of a novel weakly cationic poly(amino acid)s shell and clustered magnetite nanoparticles as a core were prepared and evaluated as a potent MR imaging contrast agent based on their superior physicochemical and magnetic properties and the effective MR imaging of cancer in vitro and in vivo.