A dual ligand targeted nanoprobe with high MRI sensitivity for diagnosis of breast cancer

Antibody targeted delivery is an effective strategy to improve the diagnostic imaging outcome of nanoscale imaging agents in the focal areas.Dual targeting micelles encapsulating superparamagnetic iron oxide were prepared from the amphiphilic block copolymer poly(ethylene glycol)-poly(ε-caprolactone)(PEG-b-PCL) with different targeting ligands cRGD and scFv-ErbB single chain antibody conjugated to the distal ends of PEG block.The breast cancer animal model was established by subcutaneous injecting the BT474 cells into the BALB/c-nu female nude mice and then employed to assess the potential of the dual ligand targeted magnetic micelles as a novel MRI contrast agent on a 1.5 T clinical MRI scanner.The T2 signal intensity of the tumor in animals receiving the dual ligand targeted magnetic micelles via tail vein decreased more significantly than the single ligand targeted and nontargeted magnetic micelles.These results indicate that the dual ligand targeted magnetic micelles,cRGD/scFv-ErbB-PEG-PCL-SPION,have great potential to act as a new type of effective nanoscale MRI contrast agent for early diagnosis of breast cancer.