The A₃ adenosine receptor (AR) is a G protein‐coupled receptor (GPCR) overexpressed in the membrane of specific cancer cells. Thus, the development of nanosystems targeting this receptor could be a strategy to both treat and diagnose cancer. Iron‐filled carbon nanotubes (CNTs) are an optimal platform for theranostic purposes, and the use of a magnetic field can be exploited for cancer magnetic cell sorting and thermal therapy. In this work, we have conjugated an A₃AR ligand on the surface of iron‐filled CNTs with the aim of targeting cells overexpressing A₃ARs. In particular, two conjugates bearing PEG linkers of different length were designed. A docking analysis of A₃AR showed that neither CNT nor linker interferes with ligand binding to the receptor; this was confirmed by in vitro preliminary radioligand competition assays on A₃AR. Encouraged by this result, magnetic cell sorting was applied to a mixture of cells overexpressing or not the A₃AR in which our compound displayed indiscriminate binding to all cells. Despite this, it is the first time that a GPCR ligand has been anchored to a magnetic nanosystem, thus it opens the door to new applications for cancer treatment.

中文翻译：

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用磁性碳纳米管靶向 G 蛋白偶联受体：以 A3 腺苷受体为例。

A ₃腺苷受体 (AR) 是一种 G 蛋白偶联受体 (GPCR)，在特定癌细胞的膜中过度表达。因此，针对这种受体的纳米系统的开发可能是一种治疗和诊断癌症的策略。充铁碳纳米管 (CNT) 是用于治疗诊断的最佳平台，磁场的使用可用于癌症磁性细胞分选和热治疗。在这项工作中，我们在铁填充的碳纳米管表面结合了 A ₃ AR 配体，目的是靶向过度表达 A ₃ AR 的细胞。特别是，设计了两种带有不同长度 PEG 接头的缀合物。A _{3 的}对接分析AR 表明 CNT 和接头均不干扰配体与受体的结合；A ₃ AR 的体外初步放射性配体竞争试验证实了这一点。受这一结果的鼓舞，磁性细胞分选被应用于过表达或不表达 A ₃ AR的细胞混合物，其中我们的化合物显示出与所有细胞的无差别结合。尽管如此，这是第一次将 GPCR 配体锚定在磁性纳米系统上，从而为癌症治疗的新应用打开了大门。