Liposomes are single bilayer capsules with distinct interior compartments in which hydrophilic drugs, imaging agents, diagnostics, etc. can be sequestered from the exterior environment. The polar parts of the individual lipids face the water compartments, while the hydrophobic parts of the lipid provide a barrier in which hydrophilic or charged molecules are poorly soluble. Hydrophobic molecules can be dissolved within the bilayer. The bilayers are typically from 3 - 6 nm thick and the liposome can range from about 50 nm - 50 microns in diameter. The question asked in this review is if any one bilayer, regardless of its composition, can provide the extended drug retention, long lifetime in the circulation, active targeting to specific tissues and rapid and controllable drug release at the site of interest. As an alternative, we review methods of self-assembling multicompartment lipid structures that provide enhanced drug retention in physiological environments. We also review methods of externally targeting and triggering drug release via the near infrared heating of gold nanoshells attached to or encapsulated within bilayer vesicles.

中文翻译：

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增强脂质体保留和快速、靶向释放的新方法。


脂质体是具有独特内部隔室的单双层胶囊，其中亲水性药物、显像剂、诊断剂等可以与外部环境隔离。各个脂质的极性部分面向水室，而脂质的疏水部分提供了亲水或带电分子难溶的屏障。疏水性分子可以溶解在双层内。双层的厚度通常为3-6纳米，脂质体的直径范围为约50纳米-50微米。本综述提出的问题是，是否有任何一个双层，无论其成分如何，都可以提供延长的药物保留、较长的循环寿命、主动靶向特定组织以及在感兴趣的部位快速且可控的药物释放。作为替代方案，我们回顾了自组装多室脂质结构的方法，该结构可增强药物在生理环境中的保留。我们还回顾了通过附着或封装在双层囊泡内的金纳米壳的近红外加热来外部靶向和触发药物释放的方法。