Deckers Roel, Rome Claire, Moonen Chrit T W
Laboratory for Molecular and Functional Imaging, UMR5231 CNRS, Université Victor Segalen, Bordeaux, France.
J Magn Reson Imaging. 2008 Feb;27(2):400-9. doi: 10.1002/jmri.21272.
Local drug delivery has recently attracted much attention since it represents a strategy to increase the drug concentration at the target location and decrease systemic toxicity effects. Ultrasound can be used in different ways to trigger regional drug delivery. It can cause the local drug release from a carrier vehicle and the local increase of cell membrane permeability either by a mechanical action or by a temperature increase. Ultrasound contrast agents may enhance these effects by means of cavitation. Ultrasound can be focused deep inside the body into a small region with dimensions on the order of 1 mm. Several types of drug microcarriers have been proposed, from nano- to micrometer sized particles. The objective of real-time imaging of local drug delivery is to assure that the delivery takes place in the target region, that the drug concentration and the resulting physiological reaction are sufficient, and to intervene if necessary. Ultrasound and nuclear imaging techniques play an important role. MRI is rather insensitive but allows precise targeting of (focused) ultrasound, can provide real-time temperature maps, and gives access to a variety of imaging biomarkers that may be used to assess drug action. Examples from recent articles illustrate the potential of the principles of ultrasound-triggered local drug delivery.
局部给药近来备受关注，因为它是一种提高靶部位药物浓度并降低全身毒性作用的策略。超声可通过多种方式用于触发局部给药。它可通过机械作用或温度升高，使药物从载体中局部释放，并使细胞膜通透性局部增加。超声造影剂可通过空化作用增强这些效应。超声能够聚焦于体内深处一个尺寸约为1毫米的小区域。已经提出了几种类型的药物微载体，粒径从纳米到微米不等。局部给药实时成像的目的是确保给药发生在靶区域，确保药物浓度和由此产生的生理反应足够，并在必要时进行干预。超声和核成像技术发挥着重要作用。磁共振成像（MRI）灵敏度较低，但能精确靶向（聚焦）超声，可提供实时温度图，并能获取多种可用于评估药物作用的成像生物标志物。近期文章中的实例说明了超声触发局部给药原理的潜力。
