Estrone-Decorated Polyion Complex Micelles for Targeted Melittin Delivery to Hormone-Responsive Breast Cancer Cells.

Tumor targeting has revolutionized cancer research, especially active cellular targeting of nanoparticles, where they are specifically homed to the pathological site to deliver the therapeutics. This strategy, which involves the utilization of affinity ligands on the surface of the nanocarriers, minimizes the nonspecific uptake of nanocarriers and the subsequent harmful side effects in healthy cells. Estrone, one of the mammalian estrogens, has affinity for estrogen receptors (ERα), which are overexpressed in hormone-responsive breast cancers. Despite holding promise, the potential of estrone in active targeting of nanoparticles has barely been explored. Herein, we developed an estrone-appended polyion complex (PIC) micelle to deliver melittin, a cytotoxic peptide, to breast cancer cells. Amino functionalization of estrone was performed to conjugate estrone to the diblock polymer synthesized by reversible addition-fragmentation chain-transfer (RAFT) polymerization. Estrone-conjugated poly(ethylene glycol) methyl ether methacrylate-