Melanin is a group of natural pigments found in living organism. It can be used for positron emission tomography (PET) imaging due to its inherent chelating ability to radioactive cupric ion. This study was to prepare ⁶⁴Cu-labeled PEGylated melanin nanoparticles (⁶⁴Cu-PEG-MNPs), and to further take advantage of the enhanced permeability and retention (EPR) effect of radiolabeled nanoparticles to realize the integration of tumor diagnosis and treatment. We successfully synthesized PEG-MNPs. Saline and serum stability experiments demonstrated good stability. PET/CT showed high tumor aggregation. Moreover, ⁶⁴Cu-PEG-MNPs resulted in a therapeutic effect on the A431 tumor-bearing mice in the treatment group. The pathological results further confirmed that the therapeutic doses of ⁶⁴Cu-PEG-MNPs cause pathological changes of tumor tissues while showing minimal toxicity to normal tissues. Our data successfully demonstrate the good imaging performance of ⁶⁴Cu-PEG-MNPs on A431 tumors and further proved its therapeutic effect, highlighting a great potential in targeted radionuclide therapy.

黑色素是在生物体内发现的一组天然色素。由于其固有的对放射性铜离子的螯合能力，它可用于正电子发射断层扫描（PET）成像。本研究旨在制备^64个Cu标记的聚乙二醇化黑色素纳米颗粒（⁶⁴ Cu-PEG-MNPs），并进一步利用放射性标记的纳米颗粒增强的渗透性和保留（EPR）效应来实现肿瘤诊断和治疗的整合。我们成功地合成了PEG-MNP。盐水和血清稳定性实验证明了良好的稳定性。PET / CT显示高度肿瘤聚集。而且⁶⁴Cu-PEG-MNP对治疗组的A431荷瘤小鼠产生治疗作用。病理结果进一步证实^64个Cu-PEG-MNP的治疗剂量引起肿瘤组织的病理变化，而对正常组织的毒性最小。我们的数据成功地证明了^64种Cu-PEG-MNP在A431肿瘤上的良好成像性能，并进一步证明了其治疗效果，突出了靶向放射性核素治疗的巨大潜力。