The Singleton Department of Pediatric Radiology, Texas Children's Hospital and Baylor College of Medicine, Houston, Texas 77030; email:
Annu Rev Med. 2015;66:177-93. doi: 10.1146/annurev-med-042513-125551.
Nanoparticle imaging agents for vascular pathologies are in development, and some agents are already in clinical trials. Untargeted agents, with long circulation, are excellent blood-pool agents, but molecularly targeted agents have significant advantages due to the signal enhancement possible with nanoparticle presentation of the contrast agent molecules. Molecular targets that are accessible directly from the vasculature are optimal for such agents. Targets that are removed from the vasculature, such as those on tumor cell surfaces, have limited accessibility owing to the enhanced permeation and retention effect. Yet, efforts at molecular targeting have tested small molecules, peptides, antibodies, and most recently aptamers as possible targeting ligands. The future is bright for nanoparticle-based imaging of vascular pathologies.
正在开发用于血管病变的纳米颗粒成像剂，其中一些已经在临床试验中。无靶向的纳米颗粒具有长循环的特点，是优秀的血池成像剂，但由于纳米颗粒呈递对比剂分子可以实现信号增强，因此分子靶向的纳米颗粒具有显著的优势。对于此类成像剂，可直接从血管获得的分子靶标是最佳的。那些位于血管之外的靶标，如肿瘤细胞表面的靶标，由于增强的渗透和保留效应，其可及性有限。然而，分子靶向的努力已经测试了小分子、肽、抗体，以及最近的适配体作为可能的靶向配体。基于纳米颗粒的血管病变成像具有广阔的前景。
