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A fluorescent probe based on tetrahydro[5]helicene derivative with large Stokes shift for rapid and highly selective recognition of hydrogen sulfide
摘要： In this work, we have designed and synthesized a dinitrobenzene-sulfonate tetrahydro[5]helicene (H-DNP) as an effective fluorescent probe for detection of hydrogen sulfide (H2S). Upon the addition of H2S, a significant fluorescence enhancement (75-fold) at 495 nm can be observed with a distinct color change from colorless to yellow. Additionally, H-DNP shows low background spectroscopic signal, large Stokes Shift up to ~140 nm, good sensitivity, rapid response time less than 2 min, low detection limit (48 nM) and high selectivity towards common bio-thiols (Cysteine, Homocysteine and Glutathione). Compared with the previous dinitrophenoxy tetrahydro[5]helicene, this probe has shorter response time and lower detection limit. Most importantly, this probe H-DNP has low toxicity to cells and excellent cell permeability, which can be applied to visualize H2S in living cells.
关键词： Fluorescence,Cell imaging,Probe,4-dinitrobenzene,Helicene,2,Hydrogen sulfide
更新于2025-11-21 11:08:12
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Dual-Modal Imaging-Guided Precise Tracking of Bioorthogonally Labeled Mesenchymal Stem Cells in Mouse Brain Stroke
摘要： Non-invasive and precise stem cell tracking after transplantation in living subject is very important to monitor both stem cell destinations and their in vivo fate, which was closely related to their therapeutic efficacy. Herein, we developed bicyclo[6.1.0]nonyne (BCN)-conjugated glycol chitosan nanoparticles (BCN-NPs) as a delivery system of dual-modal stem cell imaging probes. Near-infrared fluorescent (NIRF) dye, Cy5.5, was chemically conjugated to the BCN-NPs and then oleic acid-coated superparamagnetic iron oxide nanoparticles (OA-Fe3O4 NPs) were encapsulated into BCN-NPs, in resulting Cy5.5-labeled and OA-Fe3O4 NP-encapsulated BCN-NPs (BCN-dual-NPs). For bioorthogonal labeling of human adipose-derived mesenchymal stem cells (hMSCs), firstly, hMSCs were treated with tetra-acetylated N-azidoacetyl-D-mannosamine (Ac4ManNAz) for generating azide (-N3) groups onto their surface via metabolic glycoengineering. Second, azide groups on the cell surface were successfully chemically labeled with BCN-dual-NPs via bioorthogonal click chemistry in vitro. This bioorthogonal labeling of hMSCs could greatly increase the cell labeling efficiency, safety, and imaging sensitivity, compared to only nanoparticle-derived labeling technology. The dual-modal imaging-guided precise tracking of bioorthogonally labeled hMSCs was tested in the photothrombotic stroke mouse model via intraparenchymal injection. Finally, BCN-dual-NPs-labeled hMSCs could be effectively tracked of their migration from implanted site to brain stroke lesion using NIRF/T2-weighted magnetic resonance (MR) dual-modal imaging for 14 days. Our observation would provide a potential application of bioorthogonally labeled stem cell imaging in regenerative medicine by providing safety and high labeling efficiency in vitro and in vivo.
关键词： metabolic engineering,dual-modal imaging,bioorthogonal click chemistry,stem cell tracking,imaging probe,brain stroke
更新于2025-09-16 10:30:52