Dai Xiaowen, Yue Zhilian, Eccleston Mark E, Swartling Johannes, Slater Nigel K H, Kaminski Clemens F
Department of Chemical Engineering, University of Cambridge, Cambridge, United Kingdom.
Nanomedicine. 2008 Mar;4(1):49-56. doi: 10.1016/j.nano.2007.12.002. Epub 2008 Jan 31.
Frequency domain fluorescence lifetime imaging microscopy (FLIM) has been used in combination with laser scanning confocal microscopy to study the cellular uptake behavior of the antitumor drug doxorubicin (DOX) and micellar-encapsulated DOX (PLyAd-DOX). The endocytosis uptake process of PLyAd-DOX was monitored over 72 hours using confocal microscopy, with a maximum fluorescence recorded at incubation periods around 24 hours. The micellar structure was not found to release the encapsulated DOX during the time course of imaging. FLIM revealed single lifetime distributions of PLyAd-DOX during accumulation in the cytoplasm. The free DOX in contrast was observed both in the cytoplasm and the nuclear domain of the cell, showing bimodal lifetime distributions. There was a marked dependence of the measured free-DOX lifetime on concentration within the cell, in contrast to reference experiments in aqueous solution, where no such dependence was found. The results suggest the formation of macromolecular structures inside the living cells.
频域荧光寿命成像显微镜（FLIM）已与激光扫描共聚焦显微镜结合使用，以研究抗肿瘤药物阿霉素（DOX）和胶束包裹的阿霉素（PLyAd-DOX）的细胞摄取行为。使用共聚焦显微镜在72小时内监测PLyAd-DOX的内吞摄取过程，在约24小时的孵育期记录到最大荧光。在成像过程中未发现胶束结构释放包裹的DOX。FLIM揭示了PLyAd-DOX在细胞质中积累期间的单寿命分布。相比之下，游离DOX在细胞的细胞质和核区域均被观察到，呈现双峰寿命分布。与在水溶液中的参考实验不同，在细胞内测得的游离DOX寿命对浓度有明显依赖性，在水溶液中未发现这种依赖性。结果表明活细胞内形成了大分子结构。
