C-X-C基序趋化因子受体4（CXCR4）是乳腺癌的一个有前途的治疗靶点，因为它在包括三阴性乳腺癌（TNBC）在内的所有乳腺癌分子亚型的细胞表面过度表达。在此，通过将 C-X-C 基序趋化因子 12 (CXCL12) 衍生的环肽与胰蛋白胨涂覆的 NaGdF4 纳米点（直径 5±0.5 nm，称为 Try-NaGdF4 ND）。所制备的抗 CXCR4-NaGdF4 ND 具有高纵向弛豫 (r1) 值 (21.87 mM-1S-1)、合理的生物相容性和良好的肿瘤累积能力。抗 CXCR4-NaGdF4 ND 的特性可提高肿瘤 MRI 敏感性，并在体内注射小鼠 MDA-MB-231 肿瘤模型后促进肿瘤生物治疗。使用抗 CXCR4-NaGdF4 ND 的 MRI 引导生物疗法能够抑制 46% 的肿瘤生长。此外，注射后 24 小时，在小鼠尿液中发现了约 47% 注射剂量的抗 CXCR4-NaGdF4 ND。这些发现表明，抗 CXCR4-NaGdF4 ND 能够用作乳腺癌生物治疗和 MRI 的肾脏可清除纳米药物。© 2024。作者。

C-X-C motif chemokine receptor 4 (CXCR4) is a promising therapeutic target of breast cancer because it is overexpressed on cell surface of all molecular subtypes of breast cancer including triplenegative breast cancer (TNBC). Herein, CXCR4 antagonistic peptide-NaGdF4 nanodot conjugates (termed as anti-CXCR4-NaGdF4 NDs) have been constructed for magnetic resonance imaging (MRI)-guided biotherapy of TNBC through conjugation of the C-X-C Motif Chemokine 12 (CXCL12)-derived cyclic peptide with tryptone coated NaGdF4 nanodots (5 ± 0.5 nm in diameter, termed as Try-NaGdF4 NDs). The as-prepared anti-CXCR4-NaGdF4 NDs exhibits high longitudinal relaxivity (r1) value (21.87 mM-1S-1), reasonable biocompatibility and good tumor accumulation ability. The features of anti-CXCR4-NaGdF4 NDs improve the tumor-MRI sensitivity and facilitate tumor biotherapy after injection in mouse-bearing MDA-MB-231 tumor model in vivo. MRI-guided biotherapy using anti-CXCR4-NaGdF4 NDs enables to suppress 46% tumor growth. In addition, about 47% injection dose of anti-CXCR4-NaGdF4 NDs is found in the mouse urine at 24 h post-injection. These findings demonstrate that anti-CXCR4-NaGdF4 NDs enable to be used as renal clearable nanomedicine for biotherapy and MRI of breast cancer.© 2024. The Author(s).