Asn-Gly-Arg (NGR) motifs have vasculature-homing properties via interactions with the aminopeptidase N (CD13) expressed on tumor neovasculature. Numerous NGR peptides with different molecular scaffolds have been exploited for targeted delivery of different compounds for imaging and therapy. When conjugated with NGR, complexes recognize the CD13 receptor expressed on the tumor vasculature, which improves the specificity to tumor and avoids systematic toxic reactions. Both preclinical and clinical studies performed with these products suggest that NGR-mediated vascular targeting is an effective strategy for delivering bioactive amounts of cytokines to tumor endothelial cells. For molecular imaging, radiolabeled peptides have been the most successful approach and have been translated into clinic. This review describes current data on radiolabeled tumor vasculature-homing NGR peptides for imaging and therapy.

通过与肿瘤新脉管系统上表达的氨基肽酶N（CD13）的相互作用，Asn-Gly-Arg（NGR）基序具有脉管系统归巢特性。具有不同分子支架的许多NGR肽已被用于靶向递送不同的化合物以进行成像和治疗。当与NGR偶联时，复合物可识别肿瘤血管上表达的CD13受体，从而提高了对肿瘤的特异性并避免了系统性的毒性反应。用这些产品进行的临床前和临床研究均表明，NGR介导的血管靶向是将生物活性量的细胞因子传递至肿瘤内皮细胞的有效策略。对于分子成像，放射性标记的肽是最成功的方法，并已转化为临床。