Design of a theranostic Gd (III)–Cu (I) complex to inhibit growth and metastasis of triple‐negative breast cancer

Abstract For precise personalized treatment of triple‐negative breast cancer (TNBC) and inhibition of its metastasis, we innovatively designed and synthesized a gadolinium (III)–copper(I) complex ( GdCu ) with remarkable performance in T 1 ‐weighted magnetic resonance imaging (MRI) and cytotoxicity to TNBC cells. In addition, we constructed a GdCu @apoferritin (AFt) nanoparticles (NPs) delivery system. GdCu and GdCu @AFt NPs significantly inhibited the migration and invasion of MDA‐MB‐231 cells in vitro. GdCu can significantly inhibit the growth and metastasis of TNBC in vivo. GdCu @AFt NPs not only improved the targeting ability of GdCu , showed an enhanced performance of MRI and tumor‐growth inhibition, but also decreased the systemic toxicity of GdCu in vivo. We demonstrated that GdCu and GdCu @AFt NPs prevented the growth and metastasis of TNBC by inducing mitochondria‐mediated apoptosis and inhibiting cancer cell stemness. The remarkable MRI, anticancer and anti‐metastasis capabilities of GdCu and GdCu @AFt NPs make them promising agents for the targeted theranostics of TNBC.