Dual‐Targeting Biomimetic Semiconducting Polymer Nanocomposites for Amplified Theranostics of Bone Metastasis

Abstract Bone metastasis is a type of metastatic tumors that involves the spreads of malignant tumor cells into skeleton, and its diagnosis and treatment remain a big challenge due to the unique tumor microenvironment. We herein develop osteoclast and tumor cell dual‐targeting biomimetic semiconducting polymer nanocomposites (SPFeN OC ) for amplified theranostics of bone metastasis. SPFeN OC contain semiconducting polymer and iron oxide (Fe 3 O 4 ) nanoparticles inside core and surface camouflaged hybrid membrane of cancer cells and osteoclasts. The hybrid membrane camouflage enables their targeting to both metastatic tumor cells and osteoclasts in bone metastasis through homologous targeting mechanism, thus achieving an enhanced nanoparticle accumulation in tumors. The semiconducting polymer mediates near‐infrared (NIR) fluorescence imaging and sonodynamic therapy (SDT), and Fe 3 O 4 nanoparticles are used for magnetic resonance (MR) imaging and chemodynamic therapy (CDT). Because both cancer cells and osteoclasts are killed synchronously via the combinational action of SDT and CDT, the vicious cycle in bone metastasis is broken to realize high antitumor efficacy. Therefore, 4T1 breast cancer‐based bone metastasis can be effectively detected and cured by using SPFeN OC as dual‐targeting theranostic nanoagents. This study provides an unusual biomimetic nanoplatform that simultaneously targets osteoclasts and cancer cells for amplified theranostics of bone metastasis.