Developing a Hetero-Trinuclear Erbium(III)-Copper(II) Complex Based on Apoferritin: Targeted Photoacoustic Imaging and Multimodality Therapy of Tumor.

For the integration of targeted diagnosis and treatment of tumor, we innovatively designed and synthesized a single-molecule hetero-multinuclear Er(III)-Cu(II) complex ( ErCu 2 ) and then constructed an ErCu 2 @apoferritin (AFt) nanoparticle (NP) delivery system. ErCu 2 and ErCu 2 @AFt NPs not only provided an evident photoacoustic imaging (PAI) signal of the tumor but also effectively inhibited tumor growth by integrating photothermal therapy, chemotherapy, and immunotherapy. ErCu 2 @AFt NPs improved the targeting ability and decreased the systemic toxicity of ErCu 2 in vivo . Furthermore, we confirmed that ErCu 2 and ErCu 2 @AFt NPs inhibited tumor growth by inducing apoptosis and autophagy of tumor cells and activating the immune system. The study not only provides a novel strategy to develop therapeutic metal agents but also reveals their potential for targeted accurate diagnosis and multimodality therapy of cancer.