ZD2‐Engineered Gold Nanostar@Metal‐Organic Framework Nanoprobes for T1‐Weighted Magnetic Resonance Imaging and Photothermal Therapy Specifically Toward Triple‐Negative Breast Cancer

: Compared with other subtypes of breast cancer, triple-negative breast cancer (TNBC) is seriously threatening to human life. Therefore, it is a matter of urgency to develop multifunctional nanoprobes for visualized theranostics of TNBC, achieving specific targeting toward only TNBC, but not other subtypes. Nanoscale metal-organic frameworks (MOFs) show important potential in visualized theranostics of tumors, but it is critical to synthesize well-defined core-shell MOF-based nanocomposites by encapsulating a single nanoparticle within MOF. In this study, a TNBC-targeted peptide (ZD2)-engineered, and a single gold nanostar (AuNS) coated within MIL-101-NH2 (Fe) by coating MOF with four cycles, obtain well-defined core-shell AuNS@MOF-ZD2 nanocomposites, which are expected to achieve T1 -weighted magnetic resonance imaging and photothermal therapy (PTT) specifically targeting toward TNBC. The prepared AuNS@MOF-ZD2 nanocomposites possess good biocompatibility, efficient T1 -weighted magnetic resonance (MR) relaxivity and stable photothermal conversion ability with an efficiency of 40.5%. The in vitro and in vivo characterizations prove their performances of T1 -weighted MR and PTT with a low power density of 808 nm laser, achieving excellent theranostic efficacy in TNBC. Importantly, it is demonstrated that the prepared AuNS@MOF-ZD2 nanoprobes can specifically target TNBC cells (MDA-MB-231), but not other subtypes of breast cancer cells (MDA-MB-435, MDA-MB-468, and MCF-7), indicating their promising application in visualized theranostics of breast cancers with molecular classification.