Photostable Bipolar Fluorescent Probe for Video Tracking Plasma Membranes Related Cellular Processes

Abstract

Plasma membranes can sense the stimulations and transmit the signals from extracellular environment and then make further responses through changes in locations, shapes or morphologies. Common fluorescent membrane markers are not well suited for long time tracking due to their shorter retention time inside plasma membranes and/or their lower photostability. To this end, we develop a new bipolar marker, Mem-SQAC, which can stably insert into plasma membranes of different cells and exhibits a long retention time over 30 min. Mem-SQAC also inherits excellent photostability from the BODIPY dye family. Large two-photon absorption cross sections and long wavelength fluorescence emissions further enhance the competitiveness of Mem-SQAC as a membrane marker. By using Mem-SQAC, significant morphological changes of plasma membranes have been monitored during heavy metal poisoning and drug induced apoptosis of MCF-7 cells; the change tendencies are so distinctly different from each other that they can be used as indicators to distinguish different cell injuries. Further on, the complete processes of endocytosis toward Staphylococcus aureus and Escherichia coli by RAW 264.7 cells have been dynamically tracked. It is discovered that plasma membranes take quite different actions in response to the two bacteria, information unavailable in previous research reports.

Spatiotemporally Monitoring Cell Viability through Programmable Mitochondrial Membrane Potential Transformation by Using Fluorescent Carbon Dots

“…In fact, the selectivity of molecules and nanomaterials are dependent on the combine effect of many factors such as the hydrophilicity, lipophilicity, and the number of charge. For example, BODIPY fluorophore equipped with two TPP moiety was reported to selectively stain lysosome due to the hydrophilicity of the molecule 34. Therefore, it is reasonable that the MMP‐CDs leaked out from mitochondria can be trapped by lysosome.…”

SNAP‐Tag‐Based Subcellular Protein Labeling and Fluorescent Imaging with Naphthalimides

“…The distinct green fluorescence distribution in the nuclei and red fluorescence in the mitochondria indicate that separate collections without mutual interference was obtained (Figure A). The cells expressing mitochondrial COX8A labeled with ONI‐BG were also stained with nucleus‐targeted Hoechst 33342 and the plasma‐membrane‐specific dye SQAC . ONI‐BG and SQAC were excited with a λ =850 nm pulse laser, and Hoechst 33342 was excited with a λ =760 nm pulse laser .…”

“…The cells expressing mitochondrial COX8A labeled with ONI-BG were also stainedw ith nucleus-targeted Hoechst 33342 [16] and the plasma-membrane-specific dye SQAC. [17] ONI-BGa nd SQAC were excited with a l = 850 nm pulse laser,a nd Hoechst 33342 was excited with a l = 760 nm pulse laser. [16,17] The fluorescence was collected at l = 460-500 nm for Hoechst 33342,a t l = 520-560 nm for ONI-BG, and at l = 575-630 nm for SQAC.…”

“…[17] ONI-BGa nd SQAC were excited with a l = 850 nm pulse laser,a nd Hoechst 33342 was excited with a l = 760 nm pulse laser. [16,17] The fluorescence was collected at l = 460-500 nm for Hoechst 33342,a t l = 520-560 nm for ONI-BG, and at l = 575-630 nm for SQAC. The green fluorescenced istribution in the mitochondria for labeled naphthalimide, blue fluorescencei nt he nuclei for Hoechst 33342, and red fluorescenceonthe plasma membrane for SQAC are clearly shown in Figure 7B.T hese resultsd emonstrate that simultaneous excitationa nd separate collections can be maintainede ven for three channels.…”

Binding-Directed Energy Transfer of Conjugated Polymer Materials for Dual-Color Imaging of Cell Membrane

“…16 In an attempt to achieve binding onto the living cells, the organic probes have been incorporated with a zwitterionic head group and long lipophilic chain, which is structurally similar to phospholipid molecules. [17][18][19][20][21][22] The cell internalization problem has also been encountered for the small organic membrane 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 3 probe especially after a long retention time due to their poor solubility. 17 Thus, challenges remain to develop new probes with efficient targeting ability and stable binding on the cell membrane with comprehensive application.…”