Spatiotemporal Monitoring Endocytic and Cytosolic pH Gradients with Endosomal Escaping pH-Responsive Mice liar Nanocarriers
Spatiotemporal Monitoring Endocytic and Cytosolic pH Gradients with Endosomal Escaping pH-Responsive Mice liar Nanocarriers
复制标题
利用内体逃逸 pH 响应小鼠骗子纳米载体时空监测内吞和胞质 pH 梯度
DOI：
10.1021/bm501296d
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发表时间：
2014-11-01
影响因子：
6.2
通讯作者：
Liu, Shiyong
中科院分区：
文献类型：
--
作者：
Hu, Jinming;Liu, Guhuan;Liu, Shiyong
内体逃逸对于提高基于纳米颗粒的药物和基因递送的治疗功效至关重要。长期以来，人们一直认为pH响应性聚合物纳米载体由于“质子海绵”效应而有效地帮助内体逃逸;然而，在内吞和内体逃逸过程期间由pH响应性纳米载体经受的细胞内pH（pH（i））梯度仍有待定量和阐明。我们在此报道了超灵敏的比率荧光pHi成像探针的制造，该探针具有来自双染料标记的pH响应性嵌段共聚物的强大的内体逃逸能力，其可以直接监测活细胞中的内体逃逸，并定量测量整个内吞和内体溶解过程中的pHi变化。基于胶束纳米颗粒的pHi传感器可以通过胞吞作用有效地内化到细胞中，其中发生胶束到单聚体的转变，然后内体逃逸到胞质溶胶中。该过程伴随着酸性细胞器内蓝色香豆素发射的失活和中性胞质环境内恢复的蓝色/红色双发射，允许通过胶束纳米颗粒内吞转运途径进行的整个pHi梯度的比率荧光成像。
Endosomal escape is of crucial importance to increase the therapeutic efficacy for nanoparticle-based drug and gene delivery. It has been long presumed that pH-responsive polymeric nanocarriers are potent in aiding endosomal escape due to the "proton sponge" effect; however, the intracellular pH (pH(i)) gradients subjected by pH-responsive nanocarriers during endocytic and endosomal escaping processes remain to be quantified and elucidated. We herein report the fabrication of ultrasensitive ratiometric fluorescent pHi imaging probes with robust endosomal escaping capability derived from dual dye-labeled pH-responsive block copolymers, which can directly monitor endosomal escape in living cells and quantitatively measure pHi variations during the entire endocytic and endosomolytic processes. Micellar nanoparticle-based pHi sensors could be efficiently internalized into cells via endocytosis where micelle-to-unimer transition occurs, followed by endosomal escape into the cytosol. This process is accompanied by deactivation of blue coumarin emission within acidic organelles and restored blue/red dual emissions within the neutral cytosolic milieu, allowing for ratiometric fluorescent imaging of entire pHi gradients subjected by micellar nanoparticles following the endocytic transport pathway.