A Reversibly Intramolecular Cyclization Cy5 Optical Probe for Stochastic Optical Reconstruction Microscopy in Live Cell Mitochondria

Abstract

Single molecule localization microscopy as an advanced optical imaging technique is capable of super-resolution imaging of biological targets with the size below the optical diffraction limit. It is promising to provide powerful tools for the exploration of occurrence mechanism of severe diseases and precisely therapeutic method at single cell/organelle level, which exhibits wide applications in biomedical field. Generally, stochastic optical reconstruction microscopy (STORM) is prominently dependent on large amount of imaging buffers (Redox enzymes) and thiol-containing reagents for the ideal photoblinking behaviors of optical probes. However, the imaging buffer and thiol-containing reagents are harmful for the live cells, which make it difficult to carry out STORM imaging in live cells. Therefore, it is of significance to exploit new approaches to display STORM imaging in live cells. In this work, we provided a new strategy to facilitate the design of live cell STORM imaging probes with improved photo-blinking mechanism. A new fluorescent pentamethine cyanine probe with a thiol-attachment (SHCH 2 CH 2 CH 2-) at the N-position of one indoline moiety was synthesized to show spontaneously photoblinking behavior caused by intramolecular ring-closing/-opening processes. The fluorescent probe is biologically compatible with rare cytotoxicity and suitable for the live cell imaging. The probe can exhibit excellent photo-blinking under the direct illumination of a single laser beam (656 nm) with low power density (200 W•cm-2 for solution sample and 100 W•cm-2 for cell sample, respectively), without using any imaging buffer or thiol-chemicals. And the fluorescent probe was used to test cell toxicity with CCK-8, showed almost no cytotoxicity after 24 h incubation. The photo-blinking frames were collected

A Continuous Add‐On Probe Reveals the Nonlinear Enlargement of Mitochondria in Light‐Activated Oncosis

“…It is generally accepted that ROS plays an essential role in mitochondrial damage and participates in numerous biological processes, [ 25 ] such as causing an acceleration of apoptosis or initiation of autophagy. [ 26 , 27 ] To reduce the destruction of cell biological processes by endogenous ROS, some ROS eliminator drugs have been developed, such as the commercial ROS inhibitor Apocynin, [ 28 ] which targets NADPH oxidase to inhibit the production of ROS, thereby protecting cells.…”

Enhanced temporal and spatial resolution in super‐resolution covariance imaging algorithm with deconvolution optimization

“…Nevertheless, as this dataset is not mean for SOFI, it could not demonstrate the advantage of SOFI with low SNR and dense raw images, and the molecule blinking rate and acquisition rate are relatively too slow, which cannot fully reflect the advantage of fast imaging in SOFI. So in our next paper, mitochondria labeled with blinking enhanced fluorescent pentamethine cyanine probes 37,38 in live cells will be processed with this algorithm for faster SOFI imaging.…”

Research Progress in Mitochondrial Targeting Fluorescent Probes for Hydrogen Peroxide

“…根据现有文献报道, 能够特异性定位于线粒体的荧 光探针多数基于带有正电荷的基团, 从而对线粒体进行 靶向定位 [25][26] . 探针在线粒体中的积累可以通过膜电 位、阳离子的心磷脂络合或弱酸的离子捕获来驱动 [27] .…”