ABSTRACT

Polymer micelles are composed of amphiphilic block copolymers that contain distinguished hydrophobic and hydrophilic segments. Polymer micelles are composed of amphiphilic block copolymers that contain distinguished hydrophobic and hydrophilic segments. The cyclic pentapeptide-encoded micelles have shown superb targeting efficiency in cell culture in vitro that establishes the micelle foundation for in vivo evaluations in tumor-bearing mice. To facilitate the evaluation of tumor targeting efficiency of these micelles, magnetic resonance imaging (MRI)-visible micelles have been developed. Clustering of superparamagnetic iron oxide (SPIO) particles inside the micelle core led to a dramatic increase in T2 relaxivity. SPIO nanoparticles have been extensively studied in the past decade for their use as magnetic resonance contrast agents. A new class of magnetic resonance imaging-visible nanoparticles was developed through the incorporation of hydrophobic SPIO nanoparticles inside polymer micelles.