A cancer-targetable copolymer containing tyrosine segments for labeling radioactive halogens

A series of cancer-targetable copolymers containing rhodamine and tyrosine segments were synthesized and further labeled with isotope 125I. Copolymers with different molecular weights (PRTH-1, PRTH-2 and PRTH-3) formed aggregates in water with average diameters of 66 nm, 191 nm and 137 nm, respectively. The cancer cell targeting properties of the copolymers were investigated by comparing BEL-7402 liver cancer cells and L-02 human normal liver cells. The results indicate that their targeting properties are related to the average diameters of the PRTH copolymers that self-assembled in water. PRTH-2 copolymers were selected as having the best targeting properties for cancer cells. The in vivo study of HepA mouse models based on single-photon emission computed tomography (SPECT) also showed good tumor-targeting properties of PRTH-2 labeled with 125I.