Spatiotemporal Visualization of Cell Membrane with Amphiphilic Aggregation-Induced Emission-Active Sensor

Abstract

High-fidelity monitoring of cell membrane in spatiotemporal dimensions is critically important. However, commercial fluorescence probes are stocked by aggregation-caused quenching (ACQ) effect, while the reported aggregation-induced emission (AIE)-active probes are always limited by the unspecific aggregations in biological environment. Herein, we report the rational molecular design of a state-of-the-art amphiphilic AIE luminogen (AIEgen), Membrane Tracker QMC12, using quinoline-malononitrile (QM) as the core structure to suppress ACQ effect, incorporating the positively charged pyridinium salt group to regulate the dispersity as well as strengthen the binding force to the negative charged cell membrane, and extending the alky chain to improve the anchoring ability to the cell membrane. Such membrane tracker QMC12, which disperses well in both hydrophilic and lipophilic environments, not only achieves minimal background interference and high signal-to-noise (S/N) ratio in "ultra-fast" visualizing of cell membrane, but also endows "wash-free" characteristic, even realizing the spatial view in the three dimensional (3D) multicellular spheroid model and the observation of morphology changes in temporal dimension. Moreover, QMC12 can avoid false staining and signal loss, and unprecedentedly achieve the direct observation of cell membrane's microstructure, which could better understand the 3D model to study the intercellular information exchange in spatiotemporal dimensions.

AIE-active luminogens as highly efficient free-radical ROS photogenerator for image-guided photodynamic therapy

“…After forming the pyridinium salt, the AIE-active luminogen TCM-CPS was obtained with enhanced hydrophilicity and colloidal stability in water, and exhibited lower fluorescence intensity in an aqueous system according to RIM. 42,43…”

“…Aer forming the pyridinium salt, the AIEactive luminogen TCM-CPS was obtained with enhanced hydrophilicity and colloidal stability in water, and exhibited lower uorescence intensity in an aqueous system according to RIM. 42,43 To further investigate the AIE property of TCM-CPS, the response of the uorescence to viscosity was investigated in water-glycerin mixtures. The uorescence intensity was obviously enhanced with increasing glycerin fraction due to the restricted motion of TCM-CPS resulting from the increase in the solution viscosity (Fig.…”

Unique assembly of carbonylpyridinium and chromene reveals mitochondrial thiol starvation under ferroptosis and novel ferroptosis inducer

“…Besides, the formation of o-quinone methide aer recognizing the analytes could label the proteins in the mitochondria, which may lead to mitochondrial targeting with high accuracy. 23 Although alkylpyridinium ions has extensively been employed for mitochondrial targeting, 8,24,25 there have been no reports concerning carbonylpyridinium as a mitochondrial-targeting group in the probe. Carbonylpyridinium cation is also assumed to accelerate the recognition reaction due to its excellent leaving ability.…”

The Variance of Photophysical Properties of Tetraphenylethene and Its Derivatives during Their Transitions from Dissolved States to Solid States

“…Since 2001, the terminology of aggregation-induced emission (AIE) was specifically cast by Tang et al [ 1 ] the value and potential of substantially enhanced emissions of organic compounds in aggregated solid states started to gain importance, especially for their advantages in overcoming the critical weaknesses of dyes including the aggregation-caused quenching (ACQ) of emission and the poor photobleaching characteristics [ 2 ]. Up to now, AIE luminogens (AIEgens) have been widely utilized in the fields of lighting [ 3 , 4 , 5 ], optical sensors [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ], biological therapies [ 14 , 15 , 16 , 17 , 18 , 19 , 20 ] and so on [ 21 , 22 , 23 , 24 , 25 , 26 ]. Hence, it shows the necessity to comprehensively understand the photophysical properties of AIEgens.…”