Kyung Hee University, School of Dentistry, Department of Maxillofacial Biomedical Engineering and Institute of Oral Biology, Seoul, Republic of Korea.
J Control Release. 2012 Dec 10;164(2):108-14. doi: 10.1016/j.jconrel.2012.07.010. Epub 2012 Jul 16.
Targeted drug delivery to tumor sites is one of the ultimate goals in drug delivery. Recent progress in nanoparticle engineering has certainly improved drug targeting, but the results are not as good as expected. This is largely due to the fact that nanoparticles, regardless of how advanced they are, find the target as a result of blood circulation, like the conventional drug delivery systems do. Currently, the nanoparticle-based drug delivery to the target tumor tissues is based on wrong assumptions that most of the nanoparticles, either PEGylated or not, reach the target by the enhanced permeation and retention (EPR) effect. Studies have shown that so-called targeting moieties, i.e., antibodies or ligands, on the nanoparticle surface do not really improve delivery to target tumors. Targeted drug delivery to tumor sites is associated with highly complex biological, mechanical, chemical and transport phenomena, of which characteristics vary spatiotemporally. Yet, most of the efforts have been focused on design and surface manipulation of the drug carrying nanoparticles with relatively little attention to other aspects. This article examines the current misunderstandings and the main difficulties in targeted drug delivery.
靶向肿瘤部位的药物输送是药物输送的最终目标之一。纳米颗粒工程的最新进展确实提高了药物靶向性，但结果并不如预期的那样好。这主要是因为，无论纳米颗粒多么先进，它们都像传统的药物输送系统一样，通过血液循环找到目标。目前，基于纳米颗粒的药物向靶肿瘤组织的输送基于错误的假设，即大多数纳米颗粒，无论是 PEG 化的还是非 PEG 化的，都是通过增强的渗透和保留（EPR）效应到达目标的。研究表明，纳米颗粒表面上所谓的靶向部分，即抗体或配体，并不能真正提高对靶肿瘤的输送。靶向肿瘤部位的药物输送与高度复杂的生物、机械、化学和传输现象有关，这些特征具有时空变化。然而，大多数努力都集中在设计和表面处理载药纳米颗粒上，而相对较少关注其他方面。本文研究了靶向药物输送中目前存在的误解和主要困难。
