Advanced drug delivery system utilizing a nanocarrier is the major application of nanotechnology on pharmacotherapeutics. However, despite the promising benefits and a leading trend in pharmaceutical research, nanomedicine development suffers from a poor clinical translation problem as only a handful of nanomedicine products reach the market yearly. The conventional pharmacokinetic study generally focuses only on monitoring the level of a free drug but ignores the nanocarrier's role in pharmacokinetics. One hurdle is that it is difficult to directly track intact nanocarriers in vivo to explore their pharmacokinetics. Although several imaging techniques such as radiolabeling, nuclear imaging, fluorescence imaging, etc., have been developed over the past few years, currently, one method that can successfully track the intact nanocarriers in vivo directly is by Förster resonance energy transfer (FRET). This review summarizes the application of FRET as the in vivo nanoparticle tracker for studying the in vivo pharmacokinetics of the organic nanocarriers and gives elaborative details on the techniques utilized.

利用纳米载体的先进药物递送系统是纳米技术在药物治疗中的主要应用。然而，尽管药物研究具有可喜的好处和领先的趋势，但纳米药物的开发仍存在临床转化问题，因为每年只有少数纳米药物产品进入市场。传统的药代动力学研究通常只关注监测游离药物的水平，而忽略了纳米载体在药代动力学中的作用。一个障碍是很难在体内直接追踪完整的纳米载体来探索它们的药代动力学。尽管有几种成像技术，如放射性标记、核成像、荧光成像等。, 在过去的几年中已经发展起来，目前，一种可以成功地直接在体内追踪完整纳米载体的方法是通过Förster 共振能量转移(FRET)。本综述总结了 FRET 作为体内纳米粒子跟踪器在研究有机纳米载体体内药代动力学方面的应用，并详细介绍了所使用的技术。