title: Distinguishing normal cells from cancer cells via lysosome-targetable pH biomarkers with benzo[a]phenoxazine skeleton.
abstract: In this paper, the design of a lysosome-targetable pH probe that has a fluorescent OFF (pH = 4) to ON (pH = 5-6) response is described to identify lysosomes in normal cells. The mechanism of photoinduced electron transfer with a fluorophore-based reaction (FBR-PET) was proposed. Benzo[a]phenoxazines with electro-donating aryl groups were selected, its (2,5-dimethoxyphenyl)imino-, (2-hydroxyphenyl)imino- and (2-hydroxy-5-methoxyphenyl)- imino-derivatives (probes 1a-c) were prepared and their optical responses towards pH were evaluated; their fluorescence pH titration experiments gave regularly changes with the increasing electro-donating abilities at the linked aryl groups, the (2-hydroxy-5-methoxyphenyl)iminobenzo[a]phenoxazine (probe 1c) exhibited a nearly OFF-ON response at 580-800 nm. All probes were reversible, and they showed excellent selectivity toward the proton over other competitive species. Fluorescence confocal images were performed with HeLa, KB cancer cells and V79 normal cells, probes 1a-c are all lysosome-targetable pH probes, and benzo[a]phenoxazine with (2-hydroxy-5-methoxyphenyl)imino-group (probe 1c) has potential applications in selective differentiation of normal cells from cancer cells.
authors: College of Chemistry, Chemical Engineering and Material Science, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, Soochow University, 199 Ren'Ai Road, Suzhou, 215123, China.
authors: Yan-Hua
authors: YH
authors: Zhan
authors: School of Radiation Medicine and Protection, Medicine College of Soochow University, Suzhou, 215123, China.
authors: Xiao-Jun
authors: XJ
authors: Li
authors: College of Chemistry, Chemical Engineering and Material Science, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, Soochow University, 199 Ren'Ai Road, Suzhou, 215123, China. Electronic address: sunru924@hotmail.com.
authors: Ru
authors: R
authors: Sun
authors: School of Radiation Medicine and Protection, Medicine College of Soochow University, Suzhou, 215123, China.
authors: Yu-Jie
authors: YJ
authors: Xu
authors: College of Chemistry, Chemical Engineering and Material Science, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, Soochow University, 199 Ren'Ai Road, Suzhou, 215123, China; Jiangsu Key Laboratory of Medical Optics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, 215163, China. Electronic address: ge_jianfeng@hotmail.com.
authors: Jian-Feng
authors: JF
authors: Ge
mesh_terms: D048588:Benzoxazines / Q000138:chemical synthesis / Q000737:chemistry*; D015415:Biomarkers; D002460:Cell Line; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007624:KB Cells; D008247:Lysosomes / Q000737:chemistry*; D015394:Molecular Structure
chemical_list: D048588:Benzoxazines; D015415:Biomarkers; D005456:Fluorescent Dyes
keywords: Biomarker; Lysosome; Photoinduced electron transfer; benzo[a]phenoxazinium; pH probe