Alexiev Ulrike, Volz Pierre, Boreham Alexander, Brodwolf Robert
Institute for Experimental Physics, Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany.
Institute for Experimental Physics, Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany.
Eur J Pharm Biopharm. 2017 Jul;116:111-124. doi: 10.1016/j.ejpb.2017.01.005. Epub 2017 Jan 21.
The emerging field of nanomedicine provides new approaches for the diagnosis and treatment of diseases, for symptom relief, and for monitoring of disease progression. Topical application of drug-loaded nanoparticles for the treatment of skin disorders is a promising strategy to overcome the stratum corneum, the upper layer of the skin, which represents an effective physical and biochemical barrier. The understanding of drug penetration into skin and enhanced penetration into skin facilitated by nanocarriers requires analytical tools that ideally allow to visualize the skin, its morphology, the drug carriers, drugs, their transport across the skin and possible interactions, as well as effects of the nanocarriers within the different skin layers. Here, we review some recent developments in the field of fluorescence microscopy, namely Fluorescence Lifetime Imaging Microscopy (FLIM)), for improved characterization of nanocarriers, their interactions and penetration into skin. In particular, FLIM allows for the discrimination of target molecules, e.g. fluorescently tagged nanocarriers, against the autofluorescent tissue background and, due to the environmental sensitivity of the fluorescence lifetime, also offers insights into the local environment of the nanoparticle and its interactions with other biomolecules. Thus, FLIM shows the potential to overcome several limits of intensity based microscopy.
纳米医学这一新兴领域为疾病的诊断、治疗、症状缓解以及疾病进展监测提供了新方法。局部应用载药纳米颗粒治疗皮肤疾病是一种很有前景的策略，可克服作为有效物理和生化屏障的皮肤上层——角质层。要理解药物渗透入皮肤以及纳米载体促进药物增强渗透的过程，就需要分析工具，理想情况下这些工具应能可视化皮肤及其形态、药物载体、药物、它们在皮肤中的转运以及可能的相互作用，还有纳米载体在不同皮肤层中的作用。在此，我们综述荧光显微镜领域的一些最新进展，即荧光寿命成像显微镜（FLIM），以更好地表征纳米载体、它们的相互作用以及在皮肤中的渗透情况。特别是，FLIM能够区分目标分子，如荧光标记的纳米载体与自发荧光的组织背景，并且由于荧光寿命对环境的敏感性，还能深入了解纳米颗粒的局部环境及其与其他生物分子的相互作用。因此，FLIM显示出克服基于强度的显微镜的若干局限性的潜力。
